Use of 4-bora-3a, 4a-diaza-s-indacene for security purposes

Abstract

The invention relates to the use of one or more compounds of the 4-boron-3a,4a-diaza-S-indacene family in the manufacture of a security element for a product, in particular a document, said security element comprising a polymer and said compounds being incorporated into said polymer, and to a method of ensuring the security of a product, in particular a document.

Description

[0001] This application is a divisional application of the application filed on January 9, 2017, with international application number PCT / FR2017 / 050045, national application number 201780012364.3, and entitled "4-boron-3a,4a-diaza-S-inda Province for use for safety purposes". Technical Field

[0002] This invention relates to the field of protecting and authenticating products (particularly documents) containing polymers. More specifically, this invention relates to protecting and authenticating identity, credit, or administrative documents. Background Technology

[0003] Today, counterfeiting and forgery are on the rise in many high-value-added industries, such as luxury goods, automotive and aerospace parts or packaging, and especially pharmaceuticals (such as blister packs). With the development of identity theft and, particularly in some countries, the establishment of point-based driving licenses, identity and administrative documents are increasingly becoming targets for forgery. Therefore, the protection and authentication of such products and documents are essential and raise domestic and international security concerns.

[0004] Therefore, it is necessary to continuously provide new means to effectively combat counterfeiting, especially altering original documents or counterfeits.

[0005] In the remainder of the specification, the term "document" refers to the group consisting of a support and information. The support can have different properties, different forms, and can comprise polymers or mixtures of polymers. For example, the support can be formed wholly or partially of a polymer material.

[0006] As examples of documents, specific references should be made to identity documents such as passports, ID cards, driver's licenses, or health cards, as well as credit documents such as bank notes and checks, or administrative documents such as registration certificates.

[0007] Therefore, documents can be in the form of paper, booklets, or cards, and when paper or cards are needed, information can be printed and / or etched on their surface, or when booklets are needed, information can be printed and / or etched on sheets.

[0008] Because of the significant value associated with the information it contains, the document must be secure.

[0009] In the field of document protection, various companies offer visual authentication solutions, such as those using holograms or laser etching, which makes it possible to insert information onto the body of cards made of polycarbonate (such as ID cards, health cards, or driver's licenses). Such application EP0708935 describes a holographic protective layer assembly. This assembly consists of a support film having at least one layer formed of a protective varnish, a reflective or transparent layer with diffractive microstructures, and finally an adhesive layer. Once this assembly is transferred onto a document, protection for the latter is achieved.

[0010] Subsequently, the system was improved in application WO2010 / 086522 by adding perforations to make the layers more difficult to separate. However, the assembly still consists of a large number of parts that must be assembled and are now perforated, representing limitations in technology, time, and cost.

[0011] With the development of informatics, the security of documents has been enhanced by incorporating electronic components such as chips, making forgery more difficult.

[0012] Currently, document security elements can be protected by classifying the security element according to three security levels based on the means used for detection. Thus, a Level 1 security element is an element that can be detected by at least one of the five senses or by a medium that contrasts with the background. In particular, this level includes guilloches, optically variable devices (such as rainbow printing), holograms, optically variable inks, markers, variable laser images, or multi-laser images.

[0013] Level 2 safety elements are those that can be detected using simple equipment, such as ultraviolet lamps, convex lenses, or the flash of a mobile phone. This level includes detectable elements such as microprinting and fluorescent inks, as well as fluorescent fibers or plates.

[0014] Finally, Level 3 safety elements are those that can be detected using advanced equipment, such as fluorescence spectrophotometers or electron microscopes. Specifically, this category includes nano-etched pigments and biometric chips, as well as fluorescent markers (explosive tracers) that are invisible to the naked eye.

[0015] Typically, the document incorporates multiple security elements at different levels.

[0016] While existing protection schemes are interesting, they are sometimes difficult to implement and / or control. Therefore, there is a real need for new protection methods that are easy to implement, stable, and subsequently allow for rapid control over the authenticity of products or documents while still providing a high level of security. These methods should not be mutually exclusive. Summary of the Invention

[0017] Thus, the inventors have successfully developed a means of protecting the authenticity of products including polymers, such as documents, especially identity, credit or administrative documents, as well as pharmaceutical packaging (especially blister packs), luxury goods, cosmetics, automotive and aerospace parts, or wear parts (e.g. seals) in industry.

[0018] Thanks to the developed protection mechanisms, authenticity can be controlled at the three security levels defined above.

[0019] In fact, thanks to the use of one or more compounds of the 4-boron-3a,4a-diaza-s-indavin group incorporated into polymers and, in particular, the polymer matrix constituting the document or product in question, a security element detectable at all levels has been obtained.

[0020] This application is particularly advantageous because the inventors have discovered that this family of fluorescent compounds (or one or more compounds of the 4-boron-3a, 4a-diaza-s-indarin family) can be incorporated into a polymer matrix without altering the polymer's properties.

[0021] Thus, the object of the present invention is the use of one or more compounds of the 4-boron-3a,4a-diaza-S-indarin family in the preparation of a safety element for a product (particularly a document), the safety element comprising a polymer and wherein one or more compounds of the 4-boron-3a,4a-diaza-S-indarin family are incorporated in the polymer.

[0022] For the remainder of this specification, the terms “one or more compounds of the 4-boron-3a,4a-diaza-s-indagen group” and “one or more fluorescent dyes” will be used without distinction.

[0023] Therefore, products (especially documents) protected according to the present invention will include polymers incorporating one or more fluorescent dyes. These protected documents can be certified thanks to the properties and effects imparted by the fluorescent dyes.

[0024] Therefore, polymers incorporating one or more fluorescent dyes form safety elements that can be implemented at the time of product manufacturing (especially for documents in question), and applied or integrated into the latter based on experience. Thus, within the framework of document protection, the safety element can be present in all or part of the document. These points will be further elaborated in the specification.

[0025] In any case, the obtained product (especially the document) is protected by using one or more fluorescent dyes incorporated into the polymer. This protection allows for the provision of products with a variety of effects, particularly the following: - Activation / deactivation effect (on / off): This effect corresponds to the color change observed after fluorescent stimulation of the fluorescent dye (especially by LED or UV type light sources). This provides Level 2 safety.

[0026] - Waveguide effect: Grooves within a layer or layer group cause discontinuities in the refractive index that stimulates fluorescence in the protective layer. Thus, the color observed in the grooves differs from the color observed on the rest of the layer or layer group. This provides Level 1 safety.

[0027] 4-Boron-3a,4a-diaza-s-indargen compounds are fluorescent dyes, the first of which was disclosed in 1968 (A. Treibs et al, Justus Liebigs Ann. Chem. 1968, 718, 208). Since then, several other synthetic methods have been disclosed (e.g., Chem. Eur. J., 2009, 15, 5823; J. Phys. Chem. C., 2009, 113, 11844; Chem. Eur. J., 2011, 17, 3069; J. Phys. Chem. C., 20B, 117, 5373), and many 4-boron-3a,4a-diaza-s-indargen compounds are commercially available, for example, from Thermo Fisher Scientific (Waltham, MA USA).

[0028] They exhibit remarkable absorption and emission properties, and particularly possess relatively narrow fluorescence excitation and emission bands, accompanied by a high quantum yield of 0.5–1. This makes them highly fluorescent. Furthermore, these compounds exhibit good photostability and excellent thermal stability. In fact, the fluorescent dyes according to the invention are generally stable up to 300°C. Thanks to this excellent thermal stability, these fluorescent dyes can be easily incorporated into polymer matrices in a molten state, and surprisingly, their fluorescence absorption and emission properties are not altered upon incorporation into the polymer matrix.

[0029] The use of one or more 4-boron-3a,4a-diaza-s-indarsen compounds is also highly effective, thanks to the unique combination of absorption color and specific fluorescence imparted to the polymer by the fluorescent dye, which can authenticate products protected according to the present invention (especially documents). Thus, only genuine products will simultaneously possess good fluorescence absorption and emission properties.

[0030] Therefore, thanks to the unique presence of one or more 4-boron-3a,4a-diaza-s-indarin compounds, products containing polymers according to the invention (especially documents) can be certified at the three safety levels described above by incorporating one or more 4-boron-3a,4a-diaza-s-indarin compounds into the polymer. To the applicant's knowledge, this is the first time a single safety element has allowed for such multi-level protection. In fact, in the visible spectrum, 4-boron-3a,4a-diaza-s-indarin compounds all have absorption bands, and the color perceived by the naked eye will correspond to the complementary color of the absorbed color. For example, to the naked eye, the absorbing compound corresponding to blue / green at approximately 500-520 nm will appear orange / red. Thus, this property allows for the attainment of a Level 1 safety element.

[0031] Regarding fluorescence properties, the 4-boron-3a,4a-diaza-s-indarin compounds according to the invention all possess an excitation band in the ultraviolet (UV) range and an emission band in the visible light range. Therefore, in particular, they can be excited by a UV lamp emitting light in the 100 nm–400 nm range and their fluorescence can be detected by the naked eye, making it possible to obtain a Class 2 safety element.

[0032] Finally, the emission wavelength can be determined by using a fluorescence spectrophotometer and a single-network low-resolution fluorometer (detected by a photodiode or photomultiplier tube), which provides a safety element with level 3 safety according to the invention.

[0033] Thus, thanks to the correlation between absorption and fluorescence properties, products protected according to the present invention, particularly documents, will be able to be detected at three levels.

[0034] The certification according to the present invention is understood as verifying the authenticity of a product (especially a document) by detecting the safety elements or protective devices incorporated therein. This detection of the presence or absence of coloring or fluorescence allows for the certification or non-certification of problematic products (especially documents).

[0035] Therefore, a product (especially a document) will be genuine if it has not been copied and if it contains one or more security elements. Conversely, an uncertified product will be considered fake, as it will not contain the security elements required to detect malfunctions.

[0036] The term "incorporation" refers to one or more 4-boron-3a,4a-diaza-s-indabenzene compounds being tightly integrated into a polymer to form a homogeneous mixture without any dispersion. Incorporation of one or more compounds into a polymer can be carried out in various ways.

[0037] As an example, the integration is carried out under heating. In this case, the polymer is heated to its melting temperature, and then one or more 4-boron-3a,4a-diaza-s-indasen compounds are added to the molten material before complete mixing until homogeneity is achieved.

[0038] As an example again, fluorescent dyes are integrated into a polymer in powder form. In this case, the polymer can be in the form of a photocurable resin, and a polar solvent, such as isopropanol, can be added to promote integration. A homogeneous mixture without any dispersion is then obtained by complete mixing, which will have specific applications in certain 3D printing technologies, particularly for the fabrication of holograms.

[0039] Incorporation can be carried out in all types of polymers, such as polycarbonate, polyester, polystyrene, polyethylene, polypropylene, polyterephthalic acid (PET), polyacrylate, polymethacrylate, poly(vinyl chloride), polyamide, polyaramid, ethylene vinyl acetate (EVA), polyurethane, thermoplastic polyurethane (TPU), cyanoacrylate, rosin resin, pine resin, UV-curable resin, or mixtures thereof. Preferably, incorporation can be carried out in polymers selected from polycarbonate, polyester, polypropylene, thermoplastic polyurethane, and UV-curable resin, and more preferably in polymers selected from polycarbonate, polyester, polypropylene, and mixtures thereof.

[0040] Advantageously, polymers without any UV-resistant additives will be used to optimally maintain fluorescence properties. It is also advantageous to use polymers that are transparent after formation.

[0041] The amount of fluorescent dye incorporated is required to detect absorbance and fluorescence properties. The fluorescent dyes according to the invention have the advantage of allowing performance detection even when incorporated into the polymer in very small amounts.

[0042] In practice, 0.01 wt% to 5 wt% of fluorescent dye relative to the total weight of the polymer is sufficient for detection, with a preferred amount of 0.01 wt% to 2 wt% relative to the total weight of the polymer, and even more preferably 0.01 wt% to 0.05 wt% relative to the total weight of the polymer.

[0043] Depending on the polymer formation and the desired visual effect, those skilled in the art will adjust the amount of one or more fluorescent dyes. For example, the greater the desired visual effect of transparency, the lower the amount of fluorescent dye must be, as with the thickness of the resulting form.

[0044] As described above, polymers incorporating one or more fluorescent compounds form safety elements that can be used at the time of manufacturing a product in question (particularly a document), and can also be applied or integrated into the latter based on experience. For protecting the product (particularly a document), the safety element can be present on the entire surface of the document, a portion of the surface, or even on the thickness of the document itself. For example, it can be present on the entire surface or only on the periphery, and can even form a support for the document.

[0045] Therefore, depending on the intended use, the safety element can be formed using methods known to those skilled in the art.

[0046] In practice, in one embodiment, the safety element has the form of layers or layers prepared using techniques known to those skilled in the art (e.g., lamination, extrusion, calendering, calendered extrusion, expansion extrusion with or without biaxial stretching or painting and / or coating). These techniques will be selected based on the polymer used and the final thickness of the layer or layer to be obtained. As an example, if the polymer is polycarbonate or thermoplastic polyurethane, a calendered extrusion principle is preferred. As another example, if the polymer is polypropylene, an expansion extrusion principle, particularly a biaxially stretched expansion extrusion principle, is preferred. For example, in the context of this invention, a layer group can be obtained by laminating two or more layers of polymers incorporating one or more fluorescent dyes.

[0047] This layer or group of layers has advantageous applications in protecting documents. Preferably, the layer or group of layers thus obtained is transparent.

[0048] The use of the layer or group of transparent layers according to the invention is particularly advantageous because, in addition to the effects described above, the layer or group of layers has the following effects: - Color Toggle Effect: This effect corresponds to the color change during the overlay of layers or groups of layers against a contrasting background (dark background type, especially black, or light background, especially white). Thus, the complementary color of the absorbed color on the light background and the fluorescent color on the dark background are observed. This provides Level 1 safety.

[0049] - Secondary effect: This effect corresponds to the observation of the complementary color of the absorbed color, which differs from the color observed on the surface at the edges of the layer or layer group. This provides Level 1 safety.

[0050] - Tilt / Joystick Effect: This effect corresponds to a color change in the superposition of layers or groups of layers on a reflective surface (e.g., a metallized surface), the color change depending on the viewing angle and the reflective power of the background (partial to total reflection). Thus, a change is observed in the pure color of the substrate as perceived by the naked eye, towards its fluorescent emission. This provides Level 1 safety.

[0051] - Shadowing effect: When fluorescence is stimulated by an LED or UV lamp and observed against a light-colored (especially white) background, this effect corresponds to the projection of the complementary color of the fluorescent color on the observed layer and the color absorbed against the light-colored background. This provides Level 2 safety.

[0052] Advantageously, the thickness of this layer is particularly 0.050 mm to 0.800 mm, preferably 0.200 mm to 0.600 mm, for example, about 0.400 mm. When the thickness of this layer is less than 0.100 mm, in the case of flat products (especially documents, more particularly identity, credit, or administrative documents), it is also referred to as a film and filler with specific applications and can be applied to at least a portion of one surface of the product.

[0053] The thickness of the layer or film depends on various parameters, such as the properties of the polymer used to incorporate the 4-boron-3a,4a-diaza-s-indane compound. For example, advantageously, when the polymer used for incorporation is polypropylene, the thickness of the obtained layer or film is 15 μm to 100 μm. As another example, advantageously, when the polymer used for incorporation is polycarbonate, the thickness of the obtained layer or film is 100 μm to 800 μm.

[0054] According to one specific embodiment, the layer is a film and preferably has a thickness of 1-30 μm, for example, about 10 μm. The film can be obtained according to methods known to those skilled in the art, and preferably, it is a bi-oriented film.

[0055] For example, according to this embodiment, the bi-oriented film can be a single-layer bi-oriented film or a multilayer bi-oriented film obtained by laminating multiple layers (at least one of which contains the fluorescent compound as described above). The bi-oriented film can be obtained by flat film extrusion (referred to as casting extrusion) or by ring extrusion (expansion extrusion). The polymer used to obtain the bi-oriented film can be the polymer described above, and preferably, the polymer is polypropylene. A film made of bi-oriented polypropylene is thus obtained.

[0056] In one specific implementation, the formed layer will allow the card to be manufactured using techniques known to those skilled in the art. As an example, cards made of polymers, professional cards, bank cards, or any other type of card should be mentioned. In this case, the security element is thus formed as a support for the document.

[0057] For example, the card can be obtained by laminating a multilayer polymer, at least one layer of which incorporates at least one fluorescent dye according to the invention.

[0058] In one specific embodiment, the security element is a membrane, i.e., a layer with a thickness of less than 0.100 mm (particularly 0.050 mm to 0.100 mm), used to laminate the two surfaces of a document (particularly an identity document). In another embodiment, the membrane is applied to only one of the two surfaces of the document (particularly an identity document). In yet another embodiment, the membrane is applied to only a portion of one of the two surfaces of the document (particularly an identity document). In still another embodiment, the membrane is applied to only a portion of each of the two surfaces of the document (particularly an identity document).

[0059] One or more 4-boron-3a,4a-diaza-s-indarsen compounds implemented in this invention may be selected from the following formula I:

[0060] in, R 1 It is a C1-C6 alkyl, C5-C6 cycloalkyl, C5-C6 heteroalkyl, or phenyl group, wherein the phenyl group is optionally surrounded by one or more groups selected from C1-C2 alkyl, hydroxyl, or R. 5 COO - Substitution of halogen groups; R 2 and R 2' Independently selected from hydrogen and C1-C2 alkyl groups; R 3 and R 3' The group is independently selected from hydrogen, aryl, heteroaryl, cycloalkyl, alkyl, alkenyl, and alkynyl, wherein the aryl, heteroaryl, cycloalkyl, alkyl, alkenyl, and alkynyl groups are optionally substituted by one or more groups selected from C1-C4 alkyl, aryl, hydroxyl, and ferrocene, wherein the aryl group is optionally substituted by one or more groups selected from aryl, C1-C2 alkyl, halogen, hydroxyl, dimethylamino, and nitro, wherein the aryl group is optionally substituted by C1-C2 alkyl. R 4 and R 4' The group is independently selected from aryl, heteroaryl, cycloalkyl, alkyl, and alkenyl groups, wherein the aryl, heteroaryl, cycloalkyl, alkyl, and alkenyl groups are optionally substituted by one or more groups selected from C1-C3 alkyl, aryl, hydroxyl, and ferrocene, wherein the aryl group is optionally substituted by one or more groups selected from aryl, C1-C2 alkyl, halogen, hydroxyl, dimethylamino, and nitro groups, wherein the aryl group is optionally substituted by C1-C2 alkyl groups; R 5 It is a C1-C4 alkyl or C2-C4 alkenyl; R 6 and R 6' Independently selected from halogen, C1-C4 alkyl, C2-C4 alkenyl or aryl, wherein the aryl group is optionally surrounded by one or more elements selected from C1-C2 alkyl, hydroxyl, R5 COO - It is replaced by halogen groups.

[0061] The preferred compound of formula I is one in which R 1 R 2 R 2' R 3 R 3' R 4 R 4' R 5 R 6 and R 6' One or more of the following are defined: R 1 It is a phenyl group substituted with one or more groups selected from methyl, fluorine, hydroxyl, acetyl and methyl methacrylate, preferably selected from methyl, fluorine, hydroxyl and acetyl, and more preferably selected from methyl or fluorine groups; R 2 and R 2’ Independently selected from hydrogen and methyl; R 3 and R 3’ The group is independently selected from hydrogen, C1-C3 alkyl, vinyl, aryl, heteroaryl, and adamantyl, wherein the vinyl and aryl groups are optionally substituted with one or more groups selected from phenyl and C1-C2 alkyl, and the phenyl groups are optionally substituted with one or more groups selected from C1-C2 alkyl, hydroxyl, bromine, nitro, and dimethylamino. Preferably selected from hydrogen, methyl, ethyl, n-propyl, vinyl, aryl, heteroaryl, and adamantyl, wherein the vinyl and aryl groups are optionally substituted with one or more groups selected from phenyl and C1-C2 alkyl, wherein the phenyl groups are optionally substituted with one or more groups selected from C1-C2 alkyl, hydroxyl, bromine, nitro, and dimethylamino, more preferably, R 3 and R 3’ The group is independently selected from ethyl, n-propyl, methyl, vinyl, phenyl, phenanthryl, naphthyl, pyrene, thienyl, and benzofuranyl, wherein the vinyl, aryl, and naphthyl groups are optionally substituted by one or more methyl, hydroxyl, bromine, nitro, and dimethylamino groups; R 4 and R 4’ The group is independently selected from methyl, vinyl, aryl, heteroaryl, and adamantyl, wherein the vinyl and aryl groups are optionally substituted with one or more groups selected from phenyl and C1-C2 alkyl groups, and the phenyl groups are optionally substituted with one or more groups selected from C1-C2 alkyl, hydroxyl, bromine, nitro, and dimethylamino groups. Preferably, R 4 and R 4’The group is independently selected from methyl, vinyl, phenyl, phenanthryl, naphthyl, pyrene, thiophene, and benzofuranyl, wherein the vinyl, aryl, and naphthyl groups are optionally substituted by one or more methyl, hydroxyl, bromine, nitro, and dimethylamino groups; R 5 It is methyl or vinyl; R 6 and R 6’ Independently selected from fluorine, C1-C4 alkyl, C2-C4 alkenyl or aryl, wherein the aryl group is optionally surrounded by one or more radicals selected from C1-C2 alkyl, hydroxyl, R 5 COO - Substitution with halogen groups, preferably, R 6 and R 6’ It's fluorine.

[0062] According to one embodiment, one or more 4-boron-3a,4a-diaza-s-indarsen compounds implemented in this invention may be selected from formula II:

[0063] in, R 1 It is a C1-C6 alkyl, C5-C6 cycloalkyl, C5-C6 heteroalkyl, or phenyl group, wherein the phenyl group is optionally surrounded by one or more groups selected from C1-C2 alkyl, hydroxyl, or R. 5 COO - Substitution of halogen groups; R 2 and R 2' Independently selected from hydrogen and C1-C2 alkyl groups; R 3 and R 3' Independently selected from hydrogen and C1-C3 alkyl groups; R 4 and R 4' The group is independently selected from aryl, heteroaryl, cycloalkyl, alkyl, and alkenyl groups, wherein the aryl, heteroaryl, cycloalkyl, alkyl, and alkenyl groups are optionally substituted by one or more groups selected from C1-C3 alkyl, aryl, hydroxyl, and ferrocene, wherein the aryl group is optionally substituted by one or more groups selected from aryl, C1-C2 alkyl, halogen, hydroxyl, dimethylamino, and nitro groups, wherein the aryl group is optionally substituted by C1-C2 alkyl groups; R 5 It is a C1-C4 alkyl or C2-C4 alkenyl.

[0064] In this embodiment, the preferred compound of formula I is wherein R 1 R 2 R 2' R 3 R 3' R 4R 4' and R 5 One or more of the following are defined: R 1 It is a phenyl group substituted with one or more groups selected from methyl, fluorine, hydroxyl, acetyl and methyl methacrylate, preferably selected from methyl, fluorine, hydroxyl and acetyl, and more preferably selected from methyl or fluorine groups; R 2 and R 2’ Independently selected from hydrogen and methyl; R 3 and R 3’ The components are independently selected from hydrogen, methyl, ethyl, n-propyl, and preferably ethyl; R 4 and R 4’ The group is independently selected from methyl, vinyl, aryl, heteroaryl, and adamantyl, wherein the vinyl and aryl groups are optionally substituted with one or more groups selected from phenyl and C1-C2 alkyl groups, and the phenyl groups are optionally substituted with one or more groups selected from C1-C2 alkyl, hydroxyl, bromine, nitro, and dimethylamino groups. Preferably, R 4 and R 4’ The group is independently selected from methyl, vinyl, phenyl, phenanthryl, naphthyl, pyrene, thiophene, and benzofuranyl, wherein the vinyl, aryl, and naphthyl groups are optionally substituted by one or more methyl, hydroxyl, bromine, nitro, and dimethylamino groups; R 5 It is methyl or vinyl.

[0065] The particularly preferred compounds of formula I are those listed in Table 1 below: Table 1:

[0066] Unless otherwise stated, the terms and expressions used in the description of the compounds implemented in this invention shall be interpreted in accordance with the definitions below.

[0067] The term "halogen" refers to fluorine, chlorine, bromine, or iodine. Preferred halogen groups are fluorine and bromine, with fluorine being particularly preferred.

[0068] The term "alkyl" refers to a straight-chain or branched hydrocarbon group of the formula CnH2n+1, where n is an integer greater than or equal to 1. Preferred alkyl groups are straight-chain or branched C1-C6 alkyl groups.

[0069] The term "alkenyl" refers to a straight-chain or branched unsaturated alkyl group, including one or more carbon-carbon double bonds. Suitable alkenyl groups comprise 2-6 carbon atoms, preferably 2-4 carbon atoms, and even more preferably 2 or 3 carbon atoms. Non-limiting examples of alkenyl groups are vinyl (vinyl) (ethenyl), 2-propenyl (allyl), 2-butenyl, and 3-butenyl, with vinyl and 2-propenyl being preferred.

[0070] The term "cycloalkyl" alone or as part of another group refers to a saturated monocyclic, bicyclic, or tricyclic hydrocarbon group having 3-12 carbon atoms, particularly 5-10 carbon atoms, and even more particularly 6-10 carbon atoms. Suitable cycloalkyl groups include, but are not limited to, cyclopentyl, cyclohexyl, norbornyl, and adamantyl, especially cyclohexyl and adamantyl. Preferred cycloalkyl groups include cyclohexyl, adamantyl-1-yl, and adamantyl-2-yl.

[0071] The term "aryl" refers to a polyunsaturated, aromatic, monocyclic (e.g., phenyl) or polycyclic (e.g., naphthyl, anthracene, phenanthryl, pyrene) hydrocarbon group. Preferred aryl groups include phenyl, naphthyl, anthracene, phenanthryl, and pyrene.

[0072] The term "heteroaryl" refers to an aromatic ring having 5-12 carbon atoms, wherein at least one carbon atom is substituted with an oxygen, nitrogen, or sulfur atom or -NH, wherein the nitrogen and sulfur atoms may optionally be oxidized and the nitrogen atom may optionally be quaternized; or a cyclic system containing 2-3 fused rings, each fused ring typically containing 5 or 6 atoms, wherein at least one ring is aromatic, and at least one carbon atom of at least one aromatic ring is substituted with an oxygen, nitrogen, or sulfur atom or -NH, wherein the nitrogen and sulfur atoms may optionally be oxidized and the nitrogen atom may optionally be quaternized. Examples of heteroaryl groups include furanyl, thiopheneyl, pyrroleyl, pyridyl, and benzofuranyl.

[0073] The compounds implemented in this invention can be synthesized according to methods known to those skilled in the art. In particular, reference can be made to the publications of A. Loudet et al. (Chem. Rev. 2007, 107, 4891-4932).

[0074] Another object of the present invention is the safety element as described above.

[0075] Another object of the present invention is a method for protecting a product (particularly a document) that implements the security elements as defined above.

[0076] Protection methods include: - Prepare a security element as defined above, which is capable of forming a product, particularly a document itself, or - Applied to the product, in particular the document to be protected.

[0077] In cases where the safety element cannot be formed into the product in this way, the application of the product to be protected is carried out according to the product (in particular the document to be protected) using techniques known to those skilled in the art.

[0078] For example, if the product to be protected is a document (especially an identity document), a security element can be applied by laminating it onto at least a portion of one of the surfaces of the document.

[0079] In one specific implementation, the product to be protected is a document, such as an identity, credit, or administrative document, and a security element may be applied to at least a portion of the product's surface.

[0080] In an alternative to this implementation, the safety element is a film laminated onto both surfaces of the document. Lamination can be performed under hot or cold conditions. In another alternative, the film is applied to only one of the two surfaces of the document. In yet another alternative, the film is applied to only a portion of one of the two surfaces of the document. In yet another alternative, the film is applied to only a portion of each of the two surfaces of the document.

[0081] According to another embodiment, the safety element is a film laminated on at least one surface including a reflective surface. The reflective surface is a surface whose reflectivity is controlled. For example, the reflective surface may be a metallized surface. Thus, the safety element may be a group of multiple layers, wherein at least one layer includes a metallized surface on which a polymer film incorporating a compound of the 4-boron-3a,4a-diaza-s-indarin group as described above is laminated.

[0082] In one specific embodiment, the safety element is a laminate of at least one layer of polymer without any fluorescent dye on either side, thus forming a card core.

[0083] According to one embodiment, the safety element is a varnish and can be applied to the surface of the product to be protected. In particular, the surface on which the varnish is applied can be a reflective surface. According to this embodiment, the application can be carried out by painting and / or coating, and advantageously, a layer or film with a thickness of 1 μm to 40 μm can be obtained. For the purposes of this invention, the varnish is a non-coloring composition that may consist of a binder, solvent, and optionally a diluent and / or additives.

[0084] In one specific embodiment, the safety element is ink, particularly ink for offset printing, which contains a polymer in its formulation incorporating a fluorescent compound; specifically, the polymer is a resin, particularly rosin resin or pine resin. For the purposes of this invention, the ink is a coloring composition suitable for writing, drawing, or printing.

[0085] The ink can be used to protect the product, and in particular the document, by being applied to it. Advantageously, using the ink for protection according to the invention allows for the acquisition of a layer with a thickness ranging from 1 μm to 40 μm. This application can be performed on the surface of the product, the document to be protected, or an element forming the latter. For example, the constituent element can be a reflective surface (which may or may not be metallized), a polyester or polypropylene film, which consists partially or entirely of transparent and / or reflective areas. This application can be performed using techniques known to those skilled in the art, particularly offset printing or screen printing techniques, which will be selected depending on the support of the product or document to be protected.

[0086] When used in offset printing, inks protected according to this embodiment have the advantage of limiting printhead clogging because the fluorescent component is less clogging than conventionally used pigments or dyes.

[0087] In another specific embodiment, the safety element is an adhesive comprising a polymer in which a fluorescent compound is integrated. This adhesive can be applied to the product or document to be protected for the purpose of protecting the product and, in particular, the document. For example, such a protective adhesive can be used in the manufacture of packaging.

[0088] The product to be protected can be of any nature. For example, it could be packaging (such as blister packs) or plastic, or documents such as identity, credit, or administrative documents (such as registration certificates).

[0089] The invention will be better understood using the following figures and embodiments, which are intended for illustrative purposes and not for limitation. Attached Figure Description

[0090] Figure 1 The absorption spectra of polycarbonate layers with a thickness of approximately 0.400 mm containing 0.05 wt% and 0.005 wt% fluorescent dyes, respectively, are shown.

[0091] Figure 2 The fluorescence spectrum of a polycarbonate layer with a thickness of approximately 0.400 mm containing 0.005% by weight of fluorescent dye is shown.

[0092] Figure 3 The transmission spectrum of a polycarbonate layer with a thickness of approximately 0.400 mm containing 0.1% by weight of fluorescent dye is shown. Detailed Implementation

[0093] Example 1: Prepare a transparent layer for a safety element having a polycarbonate polymer matrix incorporating a fluorescent dye.

[0094] For this embodiment of the safety element, the polymer selected is polycarbonate sold by Bayer under the reference name Makrolon® 2658.

[0095] The selected fluorescent dye is 2,8-diethyl-5,5-difluoro-10-mesityl-3,7-di(thiophen-2-yl)-5H-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaborinin-4-ium-5-uide (2,8-diethyl-5,5-difluoro-10-mesityl-3,7-di(thiophen-2-yl)-5H-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaborinin-4-ium-5-uide): .

[0096] The fluorescent dye absorbs at 590 nm and emits fluorescence at 641 nm.

[0097] To determine the amount of fluorescent dye to be incorporated to obtain a transparent layer, the following four test compositions were prepared: Composition 1: Polycarbonate Makrolon® 2658 mixed with 1% fluorescent dye.

[0098] Composition 2: Polycarbonate Makrolon® 2658 mixed with 0.05% fluorescent dye.

[0099] Composition 3: Polycarbonate Makrolon® 2658 mixed with 0.0167% fluorescent dye.

[0100] Composition 4: Polycarbonate Makrolon® 2658 mixed with 0.005% fluorescent dye.

[0101] Percentage by weight is expressed relative to the total weight of the fluorescent dye.

[0102] The four compositions were then extruded using a PLASTI-CORDER® extruder sold by BRADENDER, which has the following characteristics: - Screw diameter: 25 mm - Screw length: 40 D - Speed ​​range: 0-150 rpm - Maximum torque: 2x90 Nm - Two fill segments - Degassing section - Extrusion temperature range: 260°C - 290°C - Extrusion pressure: Environmental pressure This extruder allows for the production of granules or beads that will undergo a hot-pressing process to obtain a layer of safety components. Thus, the granules or beads are hot-pressed in a die.

[0103] The equipment used for this step is a LESCUYER press, in which the press plates are heated to 290°C and compressed at 50 bar for 2-3 minutes.

[0104] After cooling, a 10 cm × 10 cm safety element layer with a thickness of approximately 0.400 mm is obtained.

[0105] Pour in each composition and prepare a layer according to the description above.

[0106] For each layer, the absorption and fluorescence spectra were recorded.

[0107] Figure 1 The absorption spectra of polycarbonate layers incorporating 0.05% and 0.005% by weight of fluorescent dyes are shown. (Relative to λ) max The absorption spectrum of the fluorescent dye in solution at 588 nm was observed, and λ was observed. max The redshift displacement (bathochromic displacement) is measured for this layer made of polycarbonate. max In reality, the absorbance was 600 nm (0.05% fluorescent dye) and 599 nm (0.005% fluorescent dye). The maximum absorbance (abs) was also measured. max The concentration of the fluorescent dye in the solution. (45000mol.L) -1 .cm -1 The latter was determined using [method name missing]. The results are summarized in Table 2 below.

[0108] Table 2

[0109] Figure 2 The fluorescence spectra of a polycarbonate layer containing 0.005% fluorescent dye are shown at excitation wavelengths of 580 nm and 600 nm. (Relative to λ) max The fluorescence spectrum of the fluorescent dye in solution at 644 nm was observed, and λ was observed. maxA slight blue shift (hypsochromic displacement) was observed. For this layer made of polycarbonate, the measured λ was [value missing] for an excitation wavelength of 600 nm. max The actual wavelength is 641 nm, and for an excitation wavelength of 580 nm, the measured λ... max It is actually 640nm.

[0110] For light transmission, using the layer obtained from composition 1, wherein the concentration of the fluorescent dye is 0.1% by weight relative to the total weight of the polymer, the layer is nontransparent below 650 nm (see [link to composition 1]). Figure 3 ).

[0111] Composition 3 enables the formation of a transparent fluorescent safety element layer that allows light to pass through, thus allowing the color to change according to the incident light beam.

[0112] Other tests were conducted by changing the fluorescent dye used, while maintaining the same concentration. This resulted in a film with an absorption wavelength range of 516 nm–727 nm and a fluorescence wavelength range of 527 nm–742 nm.

[0113] Example 2: A transparent layer for a safety element having a polyurethane thermoplastic polymer matrix incorporating fluorescent dyes is prepared.

[0114] For this embodiment, the polymer selected is a thermoplastic polyurethane sold by Bayer under the name Desmopan® DP 9386A.

[0115] The selected fluorescent dye is 2,8-diethyl-5,5-difluoro-1,3,7,9-tetramethyl-10-(perfluorophenyl)-5H-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaborinin-4-ium-5-uide (OVM 6): .

[0116] The selected dye absorbs at 544 nm and emits fluorescence at 558 nm.

[0117] To obtain a transparent fluorescent layer, three test compositions were prepared as follows: Composition 1: Thermoplastic polyurethane Desmopan® mixed with 0.05% fluorescent dye DP 9386A.

[0118] Composition 2: Thermoplastic polyurethane Desmopan® DP 9386A mixed with 0.0167% fluorescent dye.

[0119] Composition 3: Thermoplastic polyurethane Desmopan® DP 9386A mixed with 0.005% fluorescent dye.

[0120] Percentage by weight, expressed as a percentage relative to the total weight of the fluorescent dye.

[0121] For each composition, the layer was prepared according to the same procedure as in Example 1.

[0122] The three polymers prepared using a polyurethane thermoplastic polymer matrix enable the production of layers of safety elements with the same appearance and transparency as compositions prepared using a polycarbonate polymer matrix.

[0123] Spectrophotometric analysis of the layers of the obtained safety element showed that incorporating fluorescent dyes into thermoplastic polyurethane did not alter its performance in terms of fluorescence absorption and emission.

[0124] The possibility of incorporating fluorescent dyes into the present invention is thus demonstrated.

Claims

Use of one or more compounds of the 1,4-boron-3a,4a-diaza-S-indarin group in the preparation of safety elements for products, particularly document safety elements, said safety elements comprising polymers in which said one or more compounds are incorporated, and said one or more compounds are selected from formula I: in, R 1 It is a phenyl group substituted with one or more groups selected from methyl, fluorine, hydroxyl, acetyl, and methyl methacrylate, preferably selected from methyl, fluorine, hydroxyl, and acetyl, and more preferably selected from methyl or fluorine groups; R 2 and R 2' Independently selected from hydrogen and C1-C2 alkyl groups; R 3 and R 3' The group is independently selected from hydrogen, aryl, heteroaryl, cycloalkyl, alkyl, alkenyl, alkynyl, said aryl, heteroaryl, cycloalkyl, alkyl, alkenyl and alkynyl are optionally substituted by one or more groups selected from C1-C4 alkyl, aryl, hydroxy and ferrocene, said aryl is optionally substituted by one or more groups selected from aryl, C1-C2 alkyl, halogen, hydroxy, dimethylamino, nitro, said aryl is optionally substituted by C1-C2 alkyl; R 4 and R 4' The group is independently selected from aryl, heteroaryl, cycloalkyl, alkyl, and alkenyl groups, wherein the aryl, heteroaryl, cycloalkyl, alkyl, and alkenyl groups are optionally substituted by one or more groups selected from C1-C3 alkyl, aryl, hydroxyl, and ferrocene, wherein the aryl group is optionally substituted by one or more groups selected from aryl, C1-C2 alkyl, halogen, hydroxyl, dimethylamino, and nitro groups, wherein the aryl group is optionally substituted by C1-C2 alkyl groups; R 5 It is a C1-C4 alkyl or C2-C4 alkenyl; R 6 and R 6' Independently selected from halogen, C1-C4 alkyl, C2-C4 alkenyl or aryl, wherein the aryl group is optionally surrounded by one or more elements selected from C1-C2 alkyl, hydroxyl, R 5 COO - It is replaced by halogen groups.

2. The use according to claim 1, characterized in that, One or more compounds of the 4-boron-3a,4a-diaza-s-indarin group are selected from: 。 3. The use according to any one of the preceding claims, characterized in that, The polymer is selected from polycarbonate, polyester, polystyrene, polyethylene, polypropylene, polyethylene terephthalate, polyacrylate, polymethacrylate, poly(vinyl chloride), polyamide, polyaramid, ethylene vinyl acetate (EVA), polyurethane, thermoplastic polyurethane (TPU), cyanoacrylate, rosin resin, pine resin, UV-curable resin, or mixtures thereof.

4. The use according to claim 3, characterized in that, The polymer is selected from polycarbonate, polyester, polypropylene, thermoplastic polyurethane or light-curing resin, preferably polycarbonate and thermoplastic polyurethane or mixtures thereof.

5. The use according to claim 4, characterized in that, The polymer is polycarbonate, polyester, polypropylene, or a mixture thereof.

6. The use according to any one of the preceding claims, characterized in that, The product in question is an identity, credit, or administrative document.

7. The use according to any one of claims 1-6, characterized in that, The safety element is in the form of a layer.

8. The use according to any one of claims 1-6, characterized in that, The safety element is ink or varnish.

9. The use according to any one of claims 1-6, characterized in that, The safety element is an adhesive.

10. A security element for a product, particularly a security element for a document, said security element comprising a polymer and one or more compounds of the 4-boron-3a,4a-diaza-s-indarin group, said one or more compounds being incorporated in said polymer and said one or more compounds being selected from formula I: in, R 1 It is a phenyl group substituted with one or more groups selected from methyl, fluorine, hydroxyl, acetyl and methyl methacrylate, preferably selected from methyl, fluorine, hydroxyl and acetyl, and more preferably selected from methyl or fluorine groups; R 2 and R 2' Independently selected from hydrogen and C1-C2 alkyl groups; R 3 and R 3' The group is independently selected from hydrogen, aryl, heteroaryl, cycloalkyl, alkyl, alkenyl, and ynyl, wherein the aryl, heteroaryl, cycloalkyl, alkyl, alkenyl, and ynyl groups are optionally substituted by one or more groups selected from C1-C4 alkyl, aryl, hydroxyl, and ferrocene, wherein the aryl group is optionally substituted by one or more groups selected from aryl, C1-C2 alkyl, halogen, hydroxyl, dimethylamino, and nitro, wherein the aryl group is optionally substituted by C1-C2 alkyl. R 4 and R 4' Independently selected from aryl, heteroaryl, cycloalkyl, alkyl, alkenyl, wherein the aryl, heteroaryl, cycloalkyl, alkyl, alkenyl are optionally substituted by one or more groups selected from C1-C3 alkyl, aryl, hydroxyl and ferrocene, wherein the aryl is optionally substituted by one or more groups selected from aryl, C1-C2 alkyl, halogen, hydroxyl, dimethylamino, nitro, wherein the aryl is optionally substituted by C1-C2 alkyl; R5 is a C1-C4 alkyl or C2-C4 alkenyl; R 6 and R 6' The group is independently selected from halogens, C1-C4 alkyls, C2-C4 alkenyls, or aryl groups, wherein the aryl group is optionally substituted by one or more groups selected from C1-C2 alkyls, hydroxyl groups, R5COO-, and halogens.

11. The safety element according to claim 10, characterized in that, One or more compounds of the 4-boron-3a,4a-diaza-s-indarin group are selected from: 。 12. The safety element according to any one of claims 10 and 11, characterized in that, The polymer is selected from polycarbonate, polyester, polystyrene, polyethylene, polypropylene, polyethylene terephthalate, polyacrylate, polymethacrylate, poly(vinyl chloride), polyamide, polyaramid, ethylene-vinyl acetate (EVA), polyurethane, thermoplastic polyurethane (TPU) or cyanoacrylate, rosin resin, pine resin, light-curing resin, or mixtures thereof.

13. The safety element according to claim 12, characterized in that, The polymer is selected from polycarbonate, polyester, polypropylene, thermoplastic polyurethane and photocurable resin, preferably from polycarbonate and thermoplastic polyurethane.

14. The safety element according to claim 13, characterized in that, The polymer is polycarbonate, polyester, polypropylene, or a mixture thereof.

15. The safety element according to any one of claims 10-14, characterized in that, It takes the form of layers.

16. The safety element according to claim 15, characterized in that, The thickness of the layer is 0.050mm-0.800mm, preferably 0.200mm-0.600mm, and more preferably about 0.400mm.

17. The safety element according to claim 15, characterized in that, The layer is a membrane.

18. The safety element according to claims 12 and 15, characterized in that, The polymer is polycarbonate, and it is in the form of a layer with a thickness of 100μm-800μm.

19. The safety element according to claims 12 and 15, characterized in that, The polymer is polypropylene, and it is in the form of a layer with a thickness of 15μm-100μm.

20. The safety element according to any one of claims 10-14, characterized in that, The safety element is ink or varnish.

21. The safety element according to any one of claims 10-14, characterized in that, The safety element is an adhesive.

22. A method for protecting a product, particularly a document, comprising the step of preparing a security element as defined above, said security element being capable of forming the product, particularly such a document, on itself, or being applied to the product to be protected, particularly said document.

23. The method for protection according to claim 20, characterized in that, The safety element is applied to at least a portion of the product to be protected, particularly the document.

24. The method for protection according to claim 20 or 21, characterized in that, The products to be protected are identity, credit, or administrative documents.

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