FR3011506A1 - MULTILAYER SAFETY STRUCTURE - Google Patents

Abstract

The present invention relates to a multilayer security structure (1), comprising: - a first layer (10) having at least one window (15), - a second layer (20) of polymeric plastic material, extending at least partially under the first layer and at least partially inside the window (15), - a security element (50) extending at least partially in the window (15).

Description

The present invention relates to secure multilayer structures and the manufacture of such structures. BACKGROUND In order to secure a document, it is known to use so-called "first level" security elements that are visible to the naked eye in visible light and without the use of a particular device and / or security elements. so-called "second-level" that are detectable only with a relatively simple device such as a lamp emitting in the ultraviolet or infrared. It may also be desirable to use so-called "third level" security elements capable of generating a specific signal when subjected to optoelectronic, electrical, magnetic or electromagnetic excitation. One of the aims of the present invention is in particular to provide level 3 security to multilayer structures.

In order to increase the security level of the security documents and to make their falsification more difficult, it is known to incorporate electronic devices therein. For example, identity cards are known comprising a device RH]) (radiofrequency identification device) and made from an assembly of polymeric layers. The presence of such devices sometimes creates extra thicknesses incompatible with the standards applicable to cards. Plastic cards are also known comprising an electronic contact module or a hybrid contact and non-contact module called "dual interface", for example used for bank cards. To manufacture such plastic chip cards it is known to use a method of machining a cavity and insertion of the chip into the thus machined cavity using a machine available from different manufacturers such as Muhlbauer or Ruhlamat. The application WO 01/41061 describes a method of manufacturing a "dual interface" smart card with screen-printed antenna deposited on a fibrous layer on each side of which is laminated a plastic card body. One of the card bodies is then machined to receive a hybrid chip.

No. 5,888,624 discloses a structure entirely of paper or cardboard in which is made by perforation and / or machining a housing for a chip. One of the difficulties of papermaking processes involving synthetic fibers is that such paper does not provide sharp edges by machining. However, there is an interest for a card having a contact chip with at least one outer layer based on paper. One solution would be to implant a chip in a card whose paper does not contain synthetic fibers; however, the mechanical properties of the card do not generally respond to or in a very limited way to the standards in force. Another solution would be to laminate several layers of synthetic paper, pre-punched to the size of the chip, so as to obtain the cavity having the desired shape. This necessitates rolling all the layers of paper in a marked way to obtain the required thickness according to the 1SO standard, which poses problems of industrial realization and does not make it easy to obtain a compliant card. There remains therefore a need for a board with contact chip thickness preferably substantially constant, having the required mechanical strength. SUMMARY The invention aims in particular to meet the above needs and achieves this through a multilayer security structure, comprising: a first layer having at least one window, a second layer of polymeric plastic, extending at least partially under the first layer and at least partially within the window, a security member extending at least partially within the window. The invention notably allows the insertion of a security element consisting of a contact chip, that is to say an electronic contact device, in a card structure with fibrous layers on its outer faces. Due to the presence of the polymeric plastic material of the second layer in the window, it is possible to machine this plastic material to create a cavity for accommodating the security element. Because the machined area is plastic, it is possible to obtain sharp and smooth edges, even when the first layer is a fibrous paper layer, including synthetic fibers. The first layer may have, on the opposite side to the second, a flat surface at least in the area extending around the window. By "flat surface" is meant a surface having no appreciable thickness variation, particularly perceptible tactilely. The security element can be flush with the flat surface of the first layer. The structure according to the invention preferably has a constant thickness to 20 grn, more preferably 10 p, m. The structure preferably conforms to ISO 7810 and / or 10373. First layer The first layer is preferably opaque. The first layer may have a multilayer or monolayer structure. In the case of a first layer comprising sub-layers, these are intended for example to obtain a first printable layer according to various methods, in particular by virtue of an internal underlayer, for example made of fibrous material containing safety elements and a sub-layer. external layer to be printed. The first layer may have, before lamination, a thickness of between 50 and 200 μm, preferably between 100 and 150 μm, and in the structure after lamination, a thickness of between 50 and 200 μm, preferably between 80 and 150 μm, rn. The first layer may have a compressibility, defined as the reduction of its thickness during lamination relative to the thickness before lamination, of between 10 and 25%, preferably between 12 and 18%. The first layer may be based on fibrous materials including cellulosic and / or synthetic fibers. The first layer may in particular be made of synthetic paper, in particular based on a film of high-density polyethylene (HDPE) coated on both sides, distributed by the applicant under the trademark POLYART®, or a non-fibrous material based on polyolefin loaded with silica such as TESL1N®, or in TYVEK®, or comprise a PET film sold by DuPont under the trade name MELINEX® or a polyester film, in particular from the PETix® range of AGFA, or still be a synthetic paper comprising synthetic fibers which are polyamide (PA), polyethylene (PE), polypropylene (PP), poly (ethylene terephthalate) (PET), polyvinyl alcohol (PVA) fibers aromatic polyester (for example Vectran® marketed by Kuraray), polyamide imide, polyolefin or polyacrylic fibers. The first layer may be a surface layer, at least partially defining the outer surface of the article. Alternatively, the first layer is covered by a surface layer, in particular transparent. Window The section of the window in plan view may be between 10 and 4000 min 2, preferably between 50 and 600 mm 2. The window preferably has a closed outline and is at a non-zero distance from the edges of the article. Alternatively, the window opens on at least one edge of the article, or extends from one edge to the opposite edge. The window can be made by die cutting, by wallet press, using a die punch tool or by laser cutting. Preferably, the window has a sharp edge. The window may for example have a polygonal edge, regular or not, oval, in particular elliptical, or circular. The first layer may be a fibrous layer and the window may be made by water jet cutting or on a paper machine at the time of formation of this layer or when it is still wet. The thickness of the window can be between 20 and 200 inn. Second layer The second layer may comprise a thermo-crosslinkable thermoplastic and bu material chosen to allow it to flow into the window of the first layer during a lamination operation, in particular chosen from the following nonlimiting list: PETg, PVC, PE, PC, PLA, ABS, PEC, PU, PET, PMMA, PA and polyethylene terephthalate (PETf), especially in film form. The second layer may comprise a polyester film, in particular from the PETix® range of AGFA or a PET film sold by DuPont under the trade name MELINEXe. The second layer may be made of thermoplastic polymer material, in particular with a glass transition temperature Tg of between -100 and 300 ° C., preferably between 50 ° C. and 160 ° C., measured according to the standard 1S011357.

The glass transition temperature of the second layer may be lower than that of the first layer by at least 10 ° C., or even at least 20 ° C., especially in the case of a first layer of synthetic paper. The layer may, before lamination, have a thickness that is preferably constant, between 50 and 250 μm, preferably between 120 and 180 μm. Within the structure, other than at the level of the window, the second layer may have a thickness before lamination. between 50 and 250 gm, preferably 120 to 180 gin. The ratio of the first window to the other, after lamination, between the thickness of the second layer at the window and the thickness outside the window may be between let 5, preferably let 3. After lamination, the material of the second layer may or may not cross the window entirely. The second layer may be opaque, translucent or transparent. The second layer may be colorless or colored, especially with pigments. The second layer may comprise a tracer, in particular luminescent, dispersed in its mass and / or a laser-markable compound, such as PETiX OLE®. The second layer is preferably of the same color as the first layer. The second layer may be monomateric or have a multilayer arrangement, with several sub-layers. The second layer may comprise an adhesive, for example hot-activatable. The second layer can be stretched before being placed within the structure. Security element The window may have a section of dimension greater than or equal to that of the security element. In a variant the section of the security element in top view is equal to that of the window. The section of the security element in top view is preferably smaller than the window, i.e., the window has a section larger than that of the security element.

The second layer may extend inside the window in a gap between the perimeter of the window and the security element. This gap has for example a width, measured locally perpendicularly to the periphery of the window, between 0 !. trn and 4000gm, preferably between 50um and 500um.

The width of the gap may be variable along the periphery of the window and / or the depth relative to the outer surface of the first layer. In a variant, the width of the gap is constant and non-zero all along the periphery of the window, over at least a portion of the height of the security element. The security element may be all around and / or at least part of its height, surrounded by the second layer. The security element may be a security thread, a foil, a tape or a patch, a screen, an AOB (antenna on board) electronic chip, a tactile impression, etc. Preferably, the security element is a security element. electronic device, in particular with contact. Electronic security device The electronic device may comprise an electronic chip with contact, better hybrid contact / contactless yet called "dual interface" or two electronic chips one with contact the other without contact. It is particularly advantageous that the contour of the layer receiving the portion of the electronic device provided with the contacts is sharp, so that the device remains maintained during reciprocating movements and in contact with a reading device. The electronic device may comprise an integrated antenna or be connected to an antenna, which may be wired, in particular copper or aluminum, screen-printed or etched. The electronic device can be connected to the antenna, when external, in particular by welding or gluing. The electronic device may be provided with a non-volatile memory, notably FRAM, SRAM, ROM or EEPROM, which, after its manufacture, makes it possible to record variable data, for example the name of the document holder, or even his photograph.

The memory may be, during the use of the electronic device to verify the authenticity of the document, read-only type or read / write. The electronic device can be chosen from contact or hybrid chips marketed by the INFINEON, NXP or ST companies, for example.

The security element is housed in a cavity of the structure, and this cavity can be stepped, especially when the security element is an electronic device which itself is stepped, such as a module. Heart of the Structure The structure according to the invention may comprise, on the side of the second layer 10 opposite to the first layer, a set of one or more additional layers which constitutes the core of the structure. The heart of the structure can be fibrous or not. More generally, the core of the structure may be of any composition, in particular paper, coated or not, plastic, synthetic paper or a mixture of these three types of materials, the core of the structure may be multilayer or monolayer. The core of the structure may be an inlay made as disclosed in application FR 2 963 275 pages 17 and 18 or a monolayer structure as disclosed in WO 2011/135497. The core of the structure may include a fluorescent coating. The core of the structure can have a thickness ranging from 50 to 400 μm. The core of the structure can partially integrate the security element, especially when it is an electronic contact or hybrid device. The heart of the structure can integrate an antenna of a hybrid electronic device capable of communicating by contact and without contact. The antenna may be deposited on the side of the core of the structure opposite to the second layer or between two layers of the core of the structure. The core of the structure may be assembled to at least one adjacent layer of the structure according to the invention by an adhesive layer, for example hot-activated or pressure-sensitive. The adhesive may be water-based or organic-solvent based, for example an acrylic, acrylonitrile, styrene butadiene, polyurethane or polyethylene adhesive. The adhesive can be crosslinkable by its nature or by the addition of a compound such as a blocked isocyanate.

Each of the first and second layers and the core of the structure, may be monolayer or multilayer. The structure may comprise one or more additional layers, located in particular on the side of the core layer opposite to the first and second layers, for example two additional layers. The structure can be symmetrical, except for the presence of the window, by the arrangement of the layers and their composition, on both sides of the core of the structure. The structure may comprise at least one transparent outer layer. Other security element (s) 10 The structure may also comprise one or more additional security elements, in particular integrated in the first layer, in the second polymer layer, or in the core of the structure. Among the additional security elements that can be integrated into a structure according to the invention, some are of the first level, being detectable with the naked eye, in daylight or in artificial light, without the use of a particular apparatus, being visible from one side of the structure or through the window if the second layer is non-opaque. These security elements comprise, for example, colored or luminescent fibers or boards, metal boards, fully or partially printed or metallized wires. The structure according to the invention may also comprise other types of second-level security elements, detectable from one side of the structure only with the aid of a relatively simple apparatus, such as a lamp emitting in the room. ultraviolet or infrared. These security elements comprise, for example, fibers, boards, strips, wires or particles. These security elements may be visible to the naked eye or not, being for example luminescent under the illumination of a Wood lamp emitting at the wavelength of 365 nm. Other types of security elements are of the third level and require for their detection a more sophisticated detection device. These security elements are for example capable of generating a specific signal when they are subjected, simultaneously or not, to one or more external excitation sources. The automatic detection of the signal makes it possible to authenticate, if necessary, the structure. These security elements comprise for example tracers in the form of active material, particles or fibers, capable of generating a specific signal when these tracers are subjected to optronic, electrical, magnetic or electromagnetic excitation. The structure may in particular comprise, as security elements, inter alia: dyes and / or luminescent pigments and / or interferential pigments and / or liquid crystal pigments, in particular in printed form or mixed with at least one polymer of at least one layer of the structure, dyes and / or photochromic or thermochromic pigments, in particular in printed form or mixed with at least one polymer of at least one layer of the structure, an ultraviolet (UV) absorber, in particular in the form coated or mixed with at least one polymer of the structure, a specific light-collecting material, for example of the "waveguide" type, for example a luminescent light-collecting material such as the commercially available polycarbonate-based polymer films by the company BAYER under the name LISA®, an interferential multilayer film, a structure with variable optical effects based on interfering pigments, or liquid crystal, a birefringent or polarizing layer, a diffraction structure, an embossed image, - means producing a "moiré effect", such an effect can for example reveal a pattern produced by the superposition of two elements within the structure, for example by bringing lines of two safety elements together, a partially reflective refi-active element, - a transparent lenticular grid, - a lens, for example a magnifying glass, - a colored filter, a flat and relatively small security element such as a board, visible or not visible, in particular luminescent, particles or agglomerates of particles, pigments or dyes of the HI-LITE type, visible or non-visible , in particular luminescent, - safety fibers, in particular metallic fibers, magnetic fibers (with soft and / or hard magnetism), or absorbers, or excitable with ultraviolet light, visi or infrared, and in particular the near infrared (N1R), - an automatically readable security having specific and measurable luminescence characteristics (eg fluorescence, phosphorescence), light absorption (eg ultraviolet, visible or infrared), Raman activity, magnetism, microwave interaction, X-ray interaction or electrical conductivity. One or more security elements as defined above can be integrated directly into one of the layers of the structure or included in one or more security elements incorporated in the structure, such as for example a wire, a foil, a band or a patch .

One or more security elements as defined above may be incorporated, in particular dispersed en masse, at least one of the layers of the structure. The structure may also comprise one or more so-called "tamper-proof" security elements, such as, for example, reagents for chemical products, for example capable of causing a color reaction in the presence of specific chemicals, for example chemicals used by the chemicals. fraudsters. The multilayer structure may include a plurality of electronic security devices. The core of the structure can integrate a non-contact electronic device and the first layer at least partially integrate an electronic device with contact.

The second layer may contain a contactless electronic device or a simple antenna. The multilayer structure may comprise an electronic device at least partially integrated with the second layer and / or the core of the structure, in particular different from the security element extending in the window.

According to another of its aspects, the invention also relates to an article, in particular a document, comprising a structure according to the invention. The document is for example in card format. The article is for example a passport, an identity card, a driving license, an interactive playing card or collectible card, a payment card or other means of payment, a voucher or a voucher, a access card, a secure label, a transport card, a loyalty card, a service card or a subscription card, or a specific payment method such as a token or a wafer used especially in casinos . Manufacturing Process According to another aspect, the invention also relates to a method of manufacturing a structure or an article according to the invention. This manufacturing method may comprise the following steps: a. the lamination, especially when hot, of at least a first layer comprising at least a first window and a second layer comprising a polymeric plastic material, at temperature and / or pressure conditions such that the second layer of material polymer flue into said at least one first window to fill it completely or partially, b. machining a cavity extending at least partially in the window, c. the removal of a safety element in the cavity thus machined. The first window can be made by laser cutting or with a punch or a pocket press or be formed on a paper machine by means of a galvano. The lamination may be carried out at a temperature Ti greater than the glass transition temperature Tg of the second layer by at least 10 ° C, especially at least 20 ° C. Preferably, the second layer of polymeric material flows into said at least one first window to fill it completely. By "completely filling the window", it should be understood that during lamination the second layer flows and overflows into the window and fills at least 95% of the volume thereof, better at least 98%, even better at least 99 %. In particular, the filling may be such that it is not possible to visually detect with the naked eye or tactilely with his finger a vacuum of material at the window.

The method may comprise a pre-assembly step in which the different layers are superimposed. These can each have, when positioned, a regular thickness, including the second polymer layer.

The layers can in particular be superimposed on the solid state. The method may comprise a step of pre-assembly by superposition of at least three layers, or even four or five layers. The structure or the document thus produced may have a constant thickness.

According to this method, the initial presence of an additional amount of polymer facing the window is not necessary. The second layer is preferably made of a film of substantially constant thickness and it is during lamination that the polymer will flow and fill the area of the window. The pressure during lamination may be from 20 to 200 N / cm 2, preferably from 20 to 100 N / cm 2. The lamination can be carried out at constant pressure or not. The pressure can be increasing or decreasing as a function of time. The lamination can be carried out hot, especially at a temperature between 100 ° C and 200 ° C, or between 110 ° C and 140 ° C. In order to facilitate creep of the polymeric material, in particular the thermoplastic material, into the window during the lamination step, its temperature may be greater than the glass transition temperature of said material by at least 10 ° C. When the second layer comprises a non-contact electronic device, the method can provide a verification step that the tuning frequency of the communication device has not been modified during the creep of the second layer, in particular because of a deformation of the antenna related to this creep. The method according to the invention can be implemented using a platen press. The multilayer structure or the document can be laminated in a plate press (for example a Burkle press) in particular under the standard lamination conditions of the plastic cards, for example PVC (120 ° C, 10 min) or polycarbonate (160 ° C). , 30 min). The conditions of temperature and pressure are chosen so that the material of the second layer flows into the window and the structure after lamination can peel off easily lamination trays. The structure or the document can be produced in a unitary manner, the various layers being previously cut in a defined format, in particular in the format. The cavity machined in the structure can be staggered. It may have dimensions equal to those of the security element to be introduced. It can be done by any usual means. "Machining" means any means for removing material, in particular by mechanical means or by laser.

It can extend totally or only partially in the window. The security element can be fixed in the cavity by any known means, for example by gluing. The security element deposited in step c) is for example an electronic device, including hybrid.

In the presence of an antenna, it can be deposited within a core structure of the structure before step a). The machining may comprise the drilling of two connection holes and in step c) the electronic chip may be connected with the antenna. In a variant, the glue used for fixing the chip also makes it possible to connect to the antenna. The method may further comprise at least one printing and / or customization step, in particular by laser engraving of one of the layers of the structure and / or ink jet printing, offset, laser toner, D2T2, transfer, flexography, heliography, screen printing and / or intaglio, especially of the first layer.

At least one or the personalization steps can be performed before and / or after the lamination step. The personalization of the card can advantageously be carried out in part by the publisher of the document. The invention will be better understood on reading the following detailed description, nonlimiting exemplary embodiments thereof, and on examining the appended drawing, in which: FIG. partial section an example of an article comprising a variant of the structure according to the invention; - FIG. 2 represents a top view of the face of the article of FIG. 1; FIGS. 3A and 3B represent in section the structure of FIG. FIG. 1, during manufacture, according to an exemplary method according to the invention; FIG. 4 illustrates another variant of the structure according to the invention; FIGS. 5A to 5C represent in section the structure of FIG. , during manufacture, - Figures 6A to 6C illustrate in partial section other structural variants according to the invention, and - Figure 7 shows in section an example of multilayer structure outside the invention. In the schematic figures, the actual relative proportions of the different layers have not necessarily been respected, for the sake of clarity of the drawing. Some layers may have been monolithically represented for the sake of simplification, while they may consist of several sub-layers in reality, as is the case for example of the core of the structure. FIGS. 1 and 2 illustrate an article 150 in the form of a card, comprising a structure according to the invention 1. The structure 1 comprises a first layer 10 defining the front 65 of the structure 1 and comprising a window 15. The latter has been realized previously, for example by perforation punch or wallet press or by laser cutting. The back 75 is defined by a layer 90. In a variant, each of the layers 10 and 90 is optionally covered with an outer surface layer, in particular transparent. The layers 10 and 90 are opaque fibrous layers, for example synthetic paper. They comprise in the illustrated example a mixture of natural and artificial fibers as described in the international application WO 2012/014412. The layers 10 and / or 90 may have been printed, in particular by offset. The layers 10 and 90 may comprise in their mass visible or non-visible security fibers.

The structure 1 comprises an inlay 31 forming the core of the structure 35, covered with a second layer 20, of thermoplastic polymer material, filling the first window 15 so as to have a flat surface 12, and covering another polymer layer 80. The two polymer layers 20 and 80 are for example PETg.

The layer 20 may be transparent, translucent or opaque. It is preferably of the same color as the first layer 10. As illustrated in Figure 1, the structure 1 may be symmetrical by the arrangement of the layers and their composition, on either side of the heart 35. The inlay 31 has a multilayer structure comprising two fibrous sub-layers 305 and 310, assembled for example by means of an adhesive layer 312, in particular a liquid adhesive. Structure 1 houses a security element 50 in a cavity 36 machined in the structure. The cavity 36 is stepped and has dimensions equal to those of the security element 50. The security element 50 is flush with the surface 12 of the front face 65 of the structure. The security element 50 extends through the window 15. As shown in FIG. 1, the insertion of the security element 50, in the illustrated example, an electronic device 53 comprising a contact chip 300, in which the cavity 36 of the structure 1, generates no extra thickness. The second layer 20 extends inside the window 15 in an interval E located between the periphery 16 of the window 15 and the security element 50. The gap E has a width /, measured locally perpendicular to the around, between Oilm and 4000pm, preferably between 50jam to 50011m. In the example shown the width / is constant and not zero. As illustrated in FIGS. 1 and 2, the second layer 20 surrounds the security element 50 all around its circumference and over part of its height. The cavity 36 extends between the first layer 10 and the back layer 90. Preferably, as illustrated, the cavity 36 is not through, being only open on the side of the first layer 10. The cavity 36 has sharp edges facilitating a good insertion of the security element 50. In the case of an electronic device 53 as illustrated, the contact portion 315 is held in place by the second layer 20 at the window 15, which allows it to resist lateral movements and facilitate the durable maintenance of the device 53.

Figure 3 A illustrates the placement of the layers before lamination. The first layer 10 has before lamination a thickness el between 50 and 200 gm, preferably between 80 and 150 Jim. The second layer 20 may have, before lamination, a thickness e2 of between 50 and 250 μm, preferably 120 to 180 μm. In a non-illustrated variant, the various pre-cut layers, for example in standardized format ID1, are introduced into a mold starting with the layer forming the reverse side of the structure and ending with the core structure incorporating, for example, an antenna, a second polymer layer and a first layer, for example synthetic paper, forming the front face of the structure and having a window. An example of a mold that can be used by a method according to the invention is described in application EP 2 279 864. During lamination, the second layer 20 of thermoplastic polymer material flows into the window 15 to fill it completely until it is flush with the Outer surface of the first layer 10, as shown in FIG. 3B. The first layer 10 has a planar surface 12, especially in the area around the window 15. Preferably, the structure 1 has, after lamination, a constant thickness, for example with a thickness equal to 760 μm +/- 80 μm. variation in thickness within the board being preferably less than or equal to 20 μm, preferably 10 μm. The lamination step can be carried out hot at a temperature TI greater than the glass transition temperature Tg of the second layer 20. Under the action of the temperature, the layer 20 flows inside the window 15 of the first layer 10. The pressure during lamination can be increasing as a function of time between 20 and 100 N / cm 2. The structure example 1 illustrated in FIG. 4 comprises a first layer 10 defining the front face 65, a second thermoplastic layer 20 and a core 35 formed of a single-layer inlay 31. The first and second layers are similar to that of the previous example. The second polymer layer extends under the entirety of the first layer and, after lamination, into the interior of the window 15, as illustrated in FIG. 5B.

The structure 1 comprises a security element 50 housed in a stepped cavity 36 machined to the dimensions of the security element 50. The latter is formed of an electronic device 53 comprising a hybrid electronic module 300 and an antenna 313 connected to the module 300 by gluing with a conductive glue via the connection holes 318. Thanks to the invention, it is advantageous that the contour of the cavity 36 receiving the device is sharp at the contact portion 315 ("leadframe" ) of the module 300, so that the device 53 is well maintained even during repeated readings. The antenna is deposited within the core 35 of the structure, on the opposite side to the second layer 20. FIG. 5C illustrates the structure 1 after machining the cavity 36 and piercing two connection holes 318 before insertion of the electronic device 53. At the core of the structure 35, the edges of the cavity have or not have cutting irregularities which do not interfere with the insertion of the device 53 not being located at the contact portion 315. variant shown in FIG. 6A, the core of the structure 35 comprises two fibrous sub-layers 305 and 310, forming, for example, a two-layer PAPERLAM structure, as in the example of FIG. 1, and the antenna 313 is deposited on one of the two layers 305 and 310, for example before receiving an adhesive layer 312. FIG. 6B illustrates in partial section for a variant of structure 1 according to the invention, a window 15 cut in a first fibrous layer 10 and in part e filled by a second thermoplastic layer underlying. Whereas in the examples of FIGS. 1, 4 and 6A, the material of the second layer 20 passes entirely through the window 15, the structure 1 illustrated in FIG. 6B comprises a security element 50, for example in the form of an electronic device 53 which is not surrounded by the second layer 20 at the surface 12 of the first layer. The contact portion 315 of the electronic device 53 completely fills the window 15. In this example, the window 15 has a section of dimension equal to that of the security element 50. FIG. 6C illustrates a structure 1 comprising a first fibrous layer 30. having a window 15 and a second layer 20 of polymeric plastic which partially extends inside the window 15. The structure 1 comprises a security element 50, for example a security thread, fully integrated with the window 15 The security element 50 is surrounded by the second layer 20 over its entire height. The material of the second layer 20 passes entirely through the window 15 and the security element 50 is flush with a flat surface 12. In the comparative example of FIG. 7, not covered by the invention, a cavity 36 has been made with conventional techniques and machines known to those skilled in the art in a structure formed of two layers 10 and 90 made of synthetic paper. surrounding a fibrous inlay 31. The machining generates irregular edges of the cavity 36, in particular at the layers 10 and 90 due to the presence of synthetic fibers. Several tests were carried out with different machines, different types of tools and different tool speeds (12000 rpm, 25000 rpm and 40000 rpm). The periphery 16 of the window 15 has, in particular, tearing off the paper which does not make it possible to satisfactorily incorporate an electronic device. EXAMPLES Example 1: Driving license This example corresponds to the variant embodiment of FIGS. 1 and 2. The structure comprises two surface layers 10 and 90 of synthetic paper, as described in the application WO 2012/014412, respectively forming the face-up 65 and verso 75, the layer 10 having a first window 15 obtained by laser perforation two layers 20 and 80 in white PETg 150 Jim thickness, an inlay 31 PAPERLAM® 20 bilayer AWSLA130TRA6 / AWSLA200TRA6, without RFID device. The front face comprises a window made by laser perforation or with a wallet press and of a dimension equal to or greater than that of the type contact module TM-3.2, sold by the company Infinéon. An ISO flat multilayer board is obtained by lamination at 120 ° C for 45min with a pressure of 20 to 100 Niai-12 increasing as a function of time. The cavity is made by a machining process. Removal of glue into the cavity and removal of the electronic module are performed for example using a machine MS330-2 Dual interface marketed by Ruhlamat. Example 2: Biometric Identity Card This example corresponds to a variant of the example illustrated in FIGS. 4, 5A to 5C comprising a core of bilayer structure.

The card consists of 6 layers: two layers 10 and 90 paper for example as defined in the patent application EP 2,598,324 and two layers 20 and 80 of 150gm thick PETg white, similar to the layers of the Example 1, as well as a bilayer PAPERLAMCD inlay, with antenna deposited by burying (wire embedding). The front face has a window made with a wallet press and a 0.1mm larger than the electronic module to integrate. The structure is laminated at 120 ° C. for 45 minutes with a pressure of between 20 and 100 N / cm 2, increasing with time. The resulting card is an ISO flat card in which a cavity is machined to receive a PM-8.4 type dual interface module marketed by the company Infinéon, as well as the two holes for making the connection between the antenna and the antenna. Contact module using a SM 5051 machine marketed by Muhlbauer. Anisotropic glue is placed in the connection holes using an FCB 1200 machine marketed by Muhlbauer, an operation generally known as "flex bump". The hybrid electronic module is then deposited in the cavity using a SCI 8210 machine marketed by Muhlbauer, the anisotropic adhesive used having both the role of glue and electrical connection between the antenna and the module. . The final card is a dual interface identity card, allowing a control of the biometric data registered in the memory of the chip via contact or contactless according to IS010373. The invention is not limited to the described embodiments. In particular, the number of layers, their nature, their thickness and their arrangement within the multilayer structure can be modified. The core of the structure is fibrous in the examples described, but may be plastic in a variant. The cavities described are staggered and have two levels. There is no departure from the invention with a non-stepped cavity, or having more than two levels.

The structure may comprise one or more adhesive layers, for example a layer formed of a TPU (thermoplastic polyurethane) film, between two of the previously described layers. The characteristics of the various embodiments can be combined with each other, within non-illustrated variants. The expression "having one" shall be understood as being synonymous with "having at least one" unless the contrary is specified.

Claims (23)

REVENDICATIONS1. Multilayer safety structure (1), comprising: a first layer (10) having at least one window (15), - a second layer (20) of polymeric plastic material extending at least partially under the first layer and at least partially partially inside the window (15), a security element (50) extending at least partially in the window (15). 2. Structure according to claim 1, the security element (50) being, all around and at least part of its height, surrounded by the second layer (20). 3. Structure according to claim 1 or 2, the window (15) having a section greater than that of the security element (50). 4. Structure according to any one of the preceding claims, the first layer (10) having the opposite side to the second layer (20), a surface (12) planar at least in the area around the window (15). 5. Structure according to the preceding claim, the security element (50) flush with the surface (12) of the first layer. 6. Structure according to any one of the preceding claims, the second layer extending inside the window in a gap (E) situated between the periphery (16) of the window (15) and the element of security (50). 7. Structure according to the preceding claim, the interval (E) having a width 1, measured perpendicularly locally to the periphery (16), between Umm and 4000gm, preferably between 50itm and 500um 25 8. Structure according to any one of the preceding claims, the security element (50) being an electronic device (53). 9. Structure according to the preceding claim, the electronic device (53) being in contact. 10. Structure according to any one of the preceding claims, 30 having a core (35) disposed on the opposite side to the first layer (10) relative to the second layer (20), the core (35) being in particular fibrous or plastic . 11. Structure according to claims 9 and 10, the electronic device (53) comprising a hybrid electronic module (300) and an antenna (313) deposited within the core (35), in particular on the opposite side to the second layer (20). or between two layers of the heart (35). 12. Structure according to any one of the preceding claims, each of the first and second layers (10, 20), and the core (35) of the structure, being monolayer or multilayer. 13. Structure according to any one of the preceding claims, comprising a stepped cavity (36) housing the security element (50). 14. Structure according to any one of the preceding claims, comprising an electronic device at least partially integrated with the second layer (20) and / or the core of the structure (35), in particular different from the security element (50). . 15. Structure according to any one of the preceding claims, the second layer (20) comprising, in particular being constituted by a thermoplastic polymer material and / or heat-curable. 16. Structure according to the preceding claim, the thermoplastic and / or thermally crosslinkable polymer material being chosen from the following list: PETg, PVC, PE, PC, PLA, ABS, PEC, PU, PET, PMMA, PA and Polyethylene Terephthalate (PETf) . 17. Structure according to any one of the preceding claims, the second layer (20) being made of thermoplastic and / or thermally crosslinkable polymer material having a glass transition temperature Tg of between -100 ° C. and 300 ° C., preferably between 50 ° C. C and 160 ° C. 18. Structure according to any one of the preceding claims, the first layer (10) being fibrous including paper or synthetic paper. 25 19. Structure according to any one of the preceding claims, the material of the second layer (20) completely through the window (15). 20. Article (100), including security document, comprising a structure (1) according to any one of the preceding claims, comprising in particular a passport, an identity card, an access card, a driving license, a playing card 30 or interactive collectible, a payment card or other means of payment, a voucher or a voucher, a secure label, a transport card, a debit card, a service card or a gift card. subscription, or a specific payment method such as a token or a wafer used in particular in casinos. 21. A method of manufacturing a multilayer security structure (1) according to any one of claims 1 to 19 or a security article according to claim 20, comprising the steps of: a. the lamination, in particular when hot, of at least a first layer (10) comprising at least a first window (15) and a second layer (20) comprising a polymeric plastic material, at temperature conditions and / or such that the second polymeric layer (20) flows into said at least one window (15) to partially fill it, and better, completely, b. machining a cavity (36) extending at least partially in the window (15). C. removing a safety element (50), in particular an electronic device (53), in particular with contact, in the cavity (36). 22. Method according to the preceding claim, the electronic device (53) comprising a hybrid electronic module (300) and an antenna (313), step a) comprising the lamination of the first and second layers (10, 20) and a core structure (35) in which the antenna (313) and step c) have been previously deposited, including the connection of the electronic module (300) with the antenna (313). 23. Method according to one of claims 21 and 22, the lamination being performed at a temperature T1 greater than the glass transition temperature Tg of the second layer (20) of at least 10 ° C.