Anti-counterfeiting marking device and process for manufacturing the same

Abstract

The present invention relates to an anti-counterfeiting marking device (10) characterised in that it comprises at least one diffraction layer (14), wherein the at least one diffraction layer (14) comprises a matrix (14a) made of a host material having a first refractive index (n1) in which nanofibers (14b) of at least a second material having a second refractive index (n2) different from the first refractive index (n1) are embedded, the host material and the second material being substantially transparent or substantially non-absorbing at least with respect to electromagnetic radiation with a wavelength in the ultraviolet and visible light spectrum.

Description

[0001] ANTI-COUNTERFEITING MARKING DEVICE AND PROCESS FOR MANUFACTURING THE SAME

[0002] TECHNICAL FIELD

[0003] The present invention relates to an anti-counterfeiting marking device, in particular capable of ensuring a high robustness against cloning, reproduction or tampering.

[0004] STATE OF THE ART

[0005] In order to protect the authenticity of banknotes, stamps, documents and car number plates, as well as goods along their distribution chain, it is known to use anticounterfeiting technologies that employ specific markers characterised by being substantially non-reproducible or tamper-evident. Reproducing or tampering such markers involve very high efforts that act as a deterrent to fraudulent reproduction activities. By way of example, let us think about the holograms imprinted on banknotes.

[0006] The anti-counterfeiting markers known today are of a different nature and are made differently and are inseparably attached to products by different techniques. Within the scope of this description and in the accompanying claims, any reference to a "product" bearing an anti-counterfeiting marking device will indiscriminately refer to goods as well as to banknotes, stamps, documents and car number plates.

[0007] Known anti-counterfeiting markers, while offering a high degree of security against their cloning or tampering, have certain drawbacks. Firstly, most of the known anticounterfeiting markers are visible to the naked eye, facilitating the task of copiers wishing to reproduce appearance thereof.

[0008] Moreover, a verification of the authenticity of known markers generally requires the use of specific tools, which the end user usually does not have. Thus, an immediate verification of the authenticity of purchased products and / or received banknotes is precluded to the end user.

[0009] Last but not least, known anti-counterfeiting markers are generally ascribable to a single unique identifier code that, in theory, could be slavishly reproduced by a fraudulent copier who had gained access to any associations between unique codes and product codes.

[0010] WO 2023 / 069471 discloses an identifier based on light scattering that includes a first multiplicity of non-transparent particles that reflect or emit light in the visible range. In order to verify the identifier, the latter is illuminated with a first light source, obtaining a first test image of the light reflected by the first multiplicity of particles. The test image is then compared with a reference model. This solution is not useful when applied on a reflective substrate.

[0011] US 8,171,567 discloses a system for marking objects in order to prevent and detect counterfeiting. In particular, the marker incorporates a number of features that make unauthorised reproduction difficult, which are dynamically reconfigurable.

[0012] US 8,558,995 discloses a structure comprising at least one substrate made of fibrous material and a plurality of heterogeneous elements randomly dispersed within the substrate, wherein at least one authentication and / or identification piece of information is related to at least one spatial and / or physical feature of the heterogeneous elements.

[0013] WO 2016 / 059005 discloses a security element composed of one at least partially transparent support; a first security structure carried by the support and defining at least a first motif visible to transmitted light; and a second security structure carried by the support, which overlaps at least partially the first structure and comprises a non-opaque masking layer and a layer with a non-diffusive, non-opaque motif, which externally covers the masking layer and defines at least a second motif visible only by reflection on the side of the motif layer, in contrast to the masking layer.

[0014] OBJECTS AND SUMMARY OF THE INVENTION

[0015] In light of the above, the task underlying the present invention is to obviate the problems of the prior art or, at least, to provide an effective alternative solution.

[0016] Within the scope of this task, the object of the present invention is to devise an anticounterfeiting marking device that offers a higher level of security against cloning, reproduction or tampering than anti-counterfeiting marking devices of the prior art.

[0017] Another object of the present invention is to make an anti-counterfeiting marking device that is invisible to the human eye when not specifically inspected by a suitable procedure.

[0018] A further object of the present invention is to devise an anti-counterfeiting marking device that can be verified by means of instruments widely used or easily accessible to end users.

[0019] Not the least of the object of the present invention is to devise an anti-counterfeiting marking device that can be made through industrially available and low-cost processes.

[0020] Yet another object of the present invention is to develop a manufacturing process for an anti-counterfeiting marking device that can be implemented quickly and easily.

[0021] According to a first aspect thereof, the invention thus relates to an anti-counterfeiting marking device comprising at least one diffraction layer, wherein the at least one diffraction layer comprises a matrix of a host material having a first refractive index in which nanofibers of at least one second material having a second refractive index different from the first refractive index are embedded, the host material and the second material being substantially transparent or substantially non-absorbing at least with respect to electromagnetic radiation having a wavelength in the ultraviolet and visible light spectrum.

[0022] The Applicant has devised a special anti-counterfeiting marking device provided with a special diffraction layer comprising nanofibers embedded in a matrix, whereby both the nanofibers and the matrix are made of materials that are substantially transparent to electromagnetic radiation with a wavelength comprised in the ultraviolet and visible light spectrum and have different refractive indexes.

[0023] As a result, the diffraction layer behaves as a grating that separates a beam of monochromatic light impinging on the marking device into a plurality of beams randomly distributed over a wide angular range. This effect is achieved, among other things, thanks to the particular size range that characterises nanofibers (100 nm - 800 nm), i.e. substantially coinciding with the wavelengths of the visible light, allowing nanofibers to behave as diffractive elements of the incident light itself. On the contrary, under normal conditions of use of the marked product, the marking device is transparent to the human eye and therefore difficult to be detected by potential counterfeiters.

[0024] In other words, by illuminating the marking device with a monochromatic activation light, a unique light pattern obtained from the set of beams generated downstream of the diffraction layer appears as transmitted or reflected. These beams are advantageously angularly distributed so as to reach a large surface area, allowing for an easy inspection by the user who can detect the pattern generated by the light beams through conventional instruments, such as a camera, e.g., a smartphone camera.

[0025] In particular, the random pattern produced by the light beams generated downstream of the diffraction layer varies according to the wavelength of the activation light. In other words, each diffraction layer is associated with an infinite number of unique random patterns.

[0026] According to a second aspect thereof, the invention relates to a process for manufacturing an anti-counterfeiting marking device comprising the steps consisting of: a. making available a substrate, optionally a peelable support substrate or a protective substrate made of a material substantially transparent or substantially nonabsorbing at least with respect to electromagnetic radiation of a wavelength comprised in the ultraviolet and visible light spectrum; b. applying on at least an internal and / or external surface of the protective layer or peelable support layer a matrix of a host material having a first refractive index and a layer of non-woven nanofiber fabric of at least a second material having a second refractive index different from the first refractive index, the host material and the second material being substantially transparent or substantially non-absorbing at least with respect to electromagnetic radiation with a wavelength comprised in the ultraviolet or visible light spectrum; and c. solidifying the host material, thereby generating a diffraction layer applicable to at least one surface of a product to be marked.

[0027] Advantageously, the manufacturing process thus configured allows to achieve the same advantages described with reference to the anti-counterfeiting marking device according to the invention.

[0028] Further features of the preferred embodiments of the anti-counterfeiting marking device and associated manufacturing process according to the present invention are the subject of the dependent claims.

[0029] The different features in the individual configurations may be combined with one another as desired, should there be advantages specifically resulting from a particular combination.

[0030] BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Further characteristics and advantages of the present invention will become clearer from the following detailed description of some preferred embodiments thereof, made with reference to the appended drawings.

[0032] In such drawings,

[0033] - Figure 1 is a schematic sectional view of an anti-counterfeiting marking device according to a first preferred embodiment of the present invention;

[0034] - Figure 2 is a block diagram of a process for manufacturing an anti-counterfeiting marking device according to a preferred embodiment of the present invention;

[0035] - Figure 3 is a schematic sectional view of an anti-counterfeiting marking device according to a second preferred embodiment of the present invention, wherein the light distribution effect achieved by the diffraction layer is schematically represented;

[0036] - Figures 4-6 are schematic sectional views of an anti-counterfeiting marking device according to a third, fourth and fifth preferred embodiment of the present invention, respectively; and - Figure 7 is a projection of the light distribution effect downstream of an anticounterfeiting marking device according to the present invention.

[0037] DETAILED DESCRIPTION OF THE INVENTION

[0038] For the illustration of the drawings, use is made in the following description of identical numerals or symbols to indicate construction elements with the same function. Moreover, for clarity of illustration, certain references may not be repeated in all drawings.

[0039] While the invention is susceptible to various modifications and alternative constructions, certain preferred embodiments are shown in the drawings and will be described hereinafter in detail. It must in any case be understood that there is no intention to limit the invention to the specific embodiment illustrated, but, on the contrary, the invention intends covering all the modifications, alternative and equivalent constructions that fall within the scope of the invention as defined in the claims.

[0040] The use of “for example”, “etc.”, “or” indicates non-exclusive alternatives without limitation unless otherwise indicated. The use of “comprises” and “includes” means “comprises or includes, but not limited to”, unless otherwise indicated.

[0041] With reference to Fig. 1, an anti-counterfeiting marking device according to a first embodiment of the present invention, collectively referred to as 10, is schematically illustrated.

[0042] The anti-counterfeiting marking device 10, hereinafter also referred to as “marker 10” for brevity, is represented in Fig. 1 applied to a peelable support layer 13, such as a layer made of silicone-impregnated cellulose.

[0043] The anti-counterfeiting marking device 10 comprises at least one diffraction layer 14 comprising a matrix 14a of a first host material having a first refractive index m in which nanofibers 14b made of at least one second material having a second refractive index n2 different from the first refractive index m (e.g., measured at a wavelength of X = 589 nm) are embedded, preferably integrally.

[0044] Both the host material 14a and the second material of which the nanofibers 14b are made are substantially transparent or substantially non-absorbing at least with respect to electromagnetic radiation with a wavelength X comprised in the ultraviolet and visible light spectrum (i.e. 200 nm < X < 740 nm).

[0045] By way of example, nanofibers are made from a solidified thermosetting acrylic resin, such as polycyanoacrylate (PECA). This material shows substantial transparency properties in solidified form. In the context of the present invention and the appended claims, “material having substantial transparency properties” is understood to mean a material having a transmittance of at least 30%, preferably at least 40%, more preferably at least 50%.

[0046] Preferably, the host material 14a shows high transparency properties in solidified form.

[0047] In the context of the present invention and the appended claims, “material having high transparency properties” is intended to mean a material having a transmittance of at least 80%, preferably at least 85%, more preferably at least 90%.

[0048] By way of example, the host material is a single-component glue that is curable when subjected to light irradiation in the ultraviolet range. Alternatively, the host material is a thermosetting adhesive material that solidifies at a temperature of at least 100 °C, preferably at least 120 °C, more preferably at a temperature of 130 °C to 140 °C.

[0049] Alternatively, the host material is a flexible silicone material.

[0050] In addition to nanofibers 14b, at least one set of nanometric elements (not illustrated) may also be embedded in the host material, such as, for example, second nanofibers made of a material different from nanofibers 14b and / or nanoparticles made of a material different from the nanofibers, where the different material is not necessarily transparent.

[0051] The marker 10 of Fig. 1 also comprises a protective layer 15, typically made of flexible or rigid material, which is substantially transparent or substantially non-absorbing at least with respect to electromagnetic radiation with a wavelength comprised in the ultraviolet and visible light spectrum, applied to a first surface of the diffraction layer 14.

[0052] By way of example, the protective layer 15 is made as a thin film of polymeric material, such as polyethylene terephthalate (PET), polyethylene (PE), polyethylene naphthalate (PEN) or polyvinylidene fluoride (PVDF), or as a sheet of glass or polymeric material, such as polymethyl methacrylate (PMMA).

[0053] In order to attach the diffraction layer 14 to the surface of a product to be marked, such as banknotes, stamps, documents, plates or products of various kinds, such as clothing, fashion accessories and so on, there is usually a substrate 11 that acts as an adhesive, which, in the embodiment of Fig. 1, is applied to a second surface of the diffraction layer 14, opposite the first surface.

[0054] The adhesive substrate 11 is also made of a material that is substantially transparent or substantially non-absorbing at least with respect to electromagnetic radiation with a wavelength comprised in the ultraviolet and visible light spectrum, such as a resin.

[0055] The manufacturing process 100 of an anti-counterfeiting marking device 10 according to the embodiment in Fig. 1, schematically illustrated in Fig. 2, involves a first step 110 wherein a sheet of rigid material is made available, intended to make the protective layer 15 of the marker 10. Alternatively, during the first step 110 a thin, flexible film of polymeric material is made available, intended, in turn, to make the protective layer 15 of the marker 10.

[0056] Next (step 120), a layer of non-woven nanofiber fabric 14b, e.g. of a solidified thermosetting acrylic resin such as polycyanoacrylate (PECA), is applied to the protective layer 15.

[0057] The layer of non-woven nanofiber fabric 14b is for example obtained by electrospinning. Such a layer 14b appears as an off-white nanofiber veil having a thickness comprised between 0.5-5 g / m2 and preferably a porosity greater than 50%, preferably greater than 60%, more preferably greater than 70%.

[0058] The nanofibers forming the layer of non-woven fabric 14b have a diameter preferably comprised between 200 - 1,500 nm, such as comprised between 400 - 800 nm.

[0059] In particular, the non-woven fabric layer 14b is obtained by an electrospinning process performed under operating conditions configured to produce a chaotic, unordered layer. By way of example, a much higher extrusion speed of the nanofiber is used for this purpose, e.g. at least 10 times higher than the relative speed between the protective layer 15 and an emitter in an electrospinning plant.

[0060] In a subsequent step (step 130), a layer of adhesive material 14a is applied to the nonwoven nanofiber fabric layer 14b, e.g. by spraying or inkjet.

[0061] The step of applying the non-woven fabric layer 14b (step 120) and adhesive layer 14a (step 130) can be performed in reverse order in order to meet specific application requirements dictated by the particular manufacturing process implemented.

[0062] After both application steps 120, 130 have been completed, the nanofibers of the nonwoven fabric layer 14b appear as dispersed in the adhesive layer 14a in a homogeneous and chaotic / unordered manner, as no separate non-woven fabric layer is any longer discernible.

[0063] The adhesive material 14a is then solidified (step 140), for example by subjecting it to light irradiation in the ultraviolet range or heat treatment.

[0064] Finally, the adhesive substrate 11 , and possibly a peelable support substrate 13 (step 150), is applied.

[0065] In a second preferred embodiment of the marker 10 according to the invention, illustrated in Fig. 3, the host material 14a and the adhesive substrate 11 are made of the same material and / or are a single layer acting both as an adhesive towards the surface of the product to be marked and as a host material 14a into which the nanofibers 14b are embedded. The host material 14a, which also acts as substrate 11, has a refractive index different from that of the nanofibers 14b.

[0066] In this case, the application steps 120, 130 take place by laying the nanofiber non-woven fabric layer 14b and the adhesive layer 14a on the peelable support layer 13, which however is not shown in Fig. 3 in order to better illustrate the operation of the anticounterfeiting marking device 10, since the peelable support layer 13 is removed at the end of the manufacturing process or in any case prior to the application of the device 10.

[0067] Figure 4 shows a third preferred embodiment of the marker 10 according to the invention, wherein, compared to the embodiment of Fig. 3, the diffraction layer 14 is coated with a protective layer 15 that preserves integrity thereof when used in an environment subjected to wearing. A peelable support layer 13 is also possible in this embodiment.

[0068] According to a fourth preferred embodiment of the marker 10 according to the invention, illustrated in Fig. 5, the adhesive substrate 11 is applied between the protective layer 15 and the diffraction layer 14. Furthermore, the adhesive substrate 11 extends along the protective layer 15 beyond the diffraction layer 14, giving the protective layer adhesive properties. Thus, the marker 10 can be applied like a traditional patch to any transparent or at least partially reflective surface of a product to be marked. Also in Fig. 5, the peelable layer 13 placed on the diffraction layer 14 on the side opposite the adhesive substrate 11 has not been shown.

[0069] According to a fifth preferred embodiment of the marker 10 according to the invention, illustrated in Fig. 6, the diffraction layer 14 comprises a host material 14a that incorporates the adhesive substrate 11 and is coated with a protective layer 15. The combination of the diffraction layer 14 and the protective layer 15 is applied to a first surface of a reflective substrate 12, e.g. a metal film or metallised polymer, which allows the marker 10 to be used even on products without transparent or at least partially reflective surfaces. The reflective substrate 12 advantageously has an adhesive substrate I la applied to a second surface that is opposite to the first surface thereof. Although not shown, a peelable support layer 13 can also be provided in this embodiment.

[0070] The operation of the anti-counterfeiting marking device 10 according to the present invention is schematically illustrated on the basis of the embodiment shown in Fig. 3.

[0071] A beam of monochromatic control light (laser light) used to verify the authenticity of the marking device 10 impinging on the diffraction layer 14 is intercepted by the nanofiber layers 14b embedded in the host material 14a of the diffraction layer 14.

[0072] Due to the fact that the size of the nanofibers 14b is in the order of magnitude of the wavelengths of the incident radiation, each nanofiber 14b has a behaviour similar to that of a diffracting element.

[0073] The diffraction layer 14 can thus be considered to exhibit a plurality of contiguous and overlapping diffracting elements that give rise to a plurality of point light sources.

[0074] The light radiations emitted by such point sources, interfering with each other in the optical path, create interference separating each light beam into a plurality of light beams.

[0075] Fig. 7 shows an example of the diffractive effect on a point laser beam by a diffraction layer 14 according to what described above applied to a surface of a product to be marked. In order to inspect a marker according to the embodiments of Fig. 1, 3, 4 and 5, the surface to which it is applied must be transparent or at least partially reflective. A marker according to the embodiment of Fig. 6 can be applied on any surface.

[0076] As can be inferred from Fig. 7, the control light beam is separated into a plurality of beams distributed over a wide angular range, wherein, however, each beam remains concentrated on a limited area, indicated in the image by its light spot. Through the comparative image of a pen visible in Fig. 7, it is possible to appreciate the size of the angular range in which the beams are distributed downstream of the interaction with the diffraction layer.

[0077] The image generated is therefore large enough to be taken and verified with image capturing instruments that are widely spread among users, such as a smartphone.

[0078] In particular, the set of beams resulting from the separation of the control beam generates a unique random image, dependent on the structure of the nanofibers, which is also random due to the special production conditions employed in the electrospinning process that produce a chaotic, unordered layer.

[0079] In particular, the random distribution of light spots within the image depends on the wavelength of the control light. Therefore, by defining a set of controls at different wavelengths, it is possible to associate a plurality of unique codes with each particular marking device.

[0080] The anti-counterfeiting marking device 10 according to the invention can be applied to a product to be marked according to different processes.

[0081] By way of example, the marking device 10 can be applied to a surface of a product to be marked. The adhesive properties of the diffraction layer 14 itself or of the adhesive substrate 11, if any, provide for the bonding of the device 10 to the application surface. On the contrary, it is possible to envisage manufacturing marking devices 10 according to the invention that are so small that they can be dispersed in a paint. In this case, the paint can be applied directly to a surface of a product to be marked.

[0082] According to a further mode of use, the marking device 10 according to the invention can be of a small size and can be inserted into an injection moulding die during moulding, hot or cold casting or during melting of a product by dispersing, within the product body, which will have to be partially transparent, one or more devices arranged in a predefined or random position in space.

[0083] For manufacturing techniques involving a heating step, it is necessary for the melting temperature of the diffraction layer 14 to be higher than the temperature of the heating step in order to preserve the marking device 10 according to the invention during the production of the product to be marked incorporating it.

[0084] The invention thus conceived is susceptible to numerous modifications and variations and the above examples should not be interpreted as limiting. Naturally, all the details can be replaced with other technically-equivalent elements.

[0085] In practice, the materials used, as well as the contingent shapes and sizes of the above- mentioned elements, can be whatever according to the requirements without for this reason departing from the scope of protection of the following claims.

Claims

CLAIMS1. Anti-counterfeiting marking device (10) characterised in that it comprises at least one diffraction layer (14), wherein the at least one diffraction layer (14) comprises a matrix (14a) of a host material having a first refractive index (m) in which nanofibers (14b) of at least a second material having a second refractive index (n2) different from the first refractive index (m) are embedded, the host material and the second material being substantially transparent or substantially non-absorbing at least with respect to electromagnetic radiation with a wavelength in the ultraviolet and visible light spectrum.

2. Marking device (10) according to claim 1, wherein the at least one second material of which the nanofibers (14b) are composed is a solidified thermosetting acrylic resin, such as poly cyanoacrylate (PEC A).

3. Marking device (10) according to claim 1 or 2, wherein the host material ( 14a) is a material that shows high transparency properties in solidified form.

4. Marking device (10) according to any one of the preceding claims, wherein the host material (14a) is a single-component glue that can be cured if subjected to light irradiation in the ultraviolet range; and / or a thermosetting adhesive material configured to solidify when subjected to a heat treatment at a temperature of at least 100 °C, preferably at least 120 °C, more preferably at a temperature of 130 °C to 140 °C; and / or a flexible silicone.

5. Marking device (10) according to any one of the preceding claims, wherein the nanofibers (14b) embedded in the matrix (14a) form a layer with a thickness between 0.5-5 g / m2; and / or wherein the nanofibers (14b) embedded in the matrix (14a) form a layer with a porosity greater than 50%, preferably greater than 60%, more preferably greater than 70%; and / or wherein the nanofibers (14b) embedded in the matrix (14a) have a diameter between 200 nm and 1,500 nm, such as between 400 nm and 800 nm.

6. Marking device (10) according to any one of the preceding claims, wherein the diffraction layer (14) is applied to a peelable support layer (13); and / orwherein the diffraction layer (14) is embedded in an adhesive substrate (11).

7. Marking device (10) according to any one of the preceding claims, comprising a protective layer (15) substantially transparent or substantially nonabsorbing at least with respect to electromagnetic radiation with a wavelength in the ultraviolet and visible light spectrum applied to a first surface of the diffraction layer (14), wherein the protective shield (15) is optionally- a sheet of glass or polymeric material, such as polymethyl methacrylate (PMMA); or- a flexible film made of polymeric material, such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN).

8. Marking device (10) according to claim 7, wherein an adhesive substrate (11) is applied to the protective layer (15), wherein the adhesive substrate (11) extends along a surface of the protective layer (15) beyond an overlap portion between the diffraction layer (14) and the protective layer (15).

9. Marking device (10) according to any one of the preceding claims, comprising a reflective support (12) applied to a second surface of the diffraction layer (14).

10. Process (100) for manufacturing a marking device (10) comprising the steps consisting of: a. making available (110) a substrate, optionally a peelable support substrate(13) or a protective substrate (15) made of a substantially transparent or substantially nonabsorbing material at least with respect to electromagnetic radiation with a wavelength in the ultraviolet and visible light spectrum; b. applying (120, 130) on at least one internal and / or external surface of the protective layer (15) or of the peelable support layer (13) a matrix (14a) of a host material having a first refractive index (m) and a layer of non-woven nanofiber fabric (14b) in at least one second material having a second refractive index (ni) different from the first refractive index (m), the host material and the second material being substantially transparent or substantially non-absorbing at least with respect to electromagnetic radiation having a wavelength in the ultraviolet or visible light spectrum; and c. solidifying (140) the host material, thereby generating a diffraction layer(14) applicable to at least one surface of a product to be marked.

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