EP2598693A1

EP2598693A1 - Security structure including phosphorescent and fluorescent compositions

Info

Publication number: EP2598693A1
Application number: EP11749537.4A
Authority: EP
Inventors: Henri Rosset
Original assignee: ArjoWiggins Security SAS
Current assignee: Oberthur Fiduciaire SAS
Priority date: 2010-07-29
Filing date: 2011-07-26
Publication date: 2013-06-05
Anticipated expiration: 2031-07-26
Also published as: PL2598693T3; KR101889526B1; ES2835182T3; KR20130132390A; CN103038418A; FR2963356A1; EP2598693B1; RU2578316C2; US20130147181A1; WO2012014151A1; CN103038418B; KR102059764B1; RS61167B1; BR112013002005B1; KR20180093135A; HUE052330T2; US10011141B2; FR2963356B1; RU2013107741A; BR112013002005A2

Abstract

The present invention relates to a security structure (10), comprising at least one first fluorescent composition (13) and at least one second phosphorescent composition (12), the first and second compositions being simultaneously excitable by a predefined illuminant from a single first surface (14) of the structure, the security structure (10) being provided in the form of a security thread, a security film, or a patch, wherein the first fluorescent composition is at least partially stacked on the second phosphorescent composition and/or the first and second compositions are used for the reference marking on the security structure.

Description

Security structure incorporating phosphorescent and fluorescent compositions

The present invention relates to security structures for combating counterfeit identity or value documents.

The invention relates more particularly to safety structures comprising luminescent substances. By "luminescent substance" is meant a fluorescent or phosphorescent substance.

Various security structures incorporating luminescent substances are known.

Thus, the application FR 2 877 609 discloses a security thread having first and second fluorescent zones emitting lights of different colors.

The application FR 2 866 036 discloses a flat security element that can incorporate a phosphor or phosphorescent substance.

The application EP 2,028,017 discloses a security structure comprising two perforated opaque layers, a first fluorescent layer being located between the first and second apertured opaque layers and a second fluorescent layer being located so as to be separated from the first fluorescent layer by one of the openwork opaque layers.

US 2002/0160188 discloses a security fiber having juxtaposed luminescent components capable of emitting blue fluorescence and red fluorescence next to each other.

The application US 2006/0014045 describes the possibility of applying a mixture of a phosphor and a phosphorescent substance to a polymer layer of a security film.

There is a need for further refinement of security structures incorporating luminescent substances, in particular to create new effects in order to make them more attractive to the observer, while being difficult to counterfeit and providing observable security to the observer. naked eye or under low magnification and under appropriate lighting.

The invention thus has, according to one of its aspects, a safety structure comprising:

at least a first fluorescent composition, at least a second phosphorescent composition, the first and second compositions being simultaneously excitable by a predefined illuminant from the same first face of the structure.

The predefined illuminant is a UV or IR illuminant, preferably UV at 365 nm.

Thanks to the invention, when the first and second compositions are excited by said illuminant, the fluorescent and phosphorescent lights can be combined or juxtaposed according to the configurations of the security structure, and produce an optical effect that is different from that observable after extinction of the illuminant, where only the light emitted by phosphorescence is likely to be perceived by the observer.

The structure can be arranged in such a way that the excitation of the compositions and the observation of the luminescence can be done only on one side of the structure.

Alternatively, the structure may be arranged such that excitation and observation can be made from each of the faces of the structure.

The first and second compositions may be arranged on the structure so as to be at least partially offset when the structure is observed from either side of the structure, and that the illuminant is placed on the side of the structure. one or other of the faces, that is to say during an observation in reflected light or transmitted. The first and second compositions can be superimposed at least partially, when the structure is observed from one or other of the faces of the structure, and this that the illuminant is placed on the side of one or other of the faces, that is to say during an observation in reflected light or transmitted.

In an exemplary embodiment, one of the first and second compositions forms a solid surface which is superimposed on the other of the first and second compositions, which forms at least one pattern.

The flat can cover all or part of the structure. The solid is for example defined by the fluorescent composition while the second composition, phosphorescent, defines the pattern. In one variant, the solid is defined by the phosphorescent composition while the fluorescent composition defines the pattern.

In an exemplary embodiment, one of the first and second compositions forms at least one pattern which, when the illumination is extinguished by the predefined illuminant, appears or disappears, or changes in appearance from a positive to negative pattern or from one color to another.

Thus, the contrast of the pattern with respect to its immediate environment can be changed between the state where the first and second compositions are illuminated by the predefined illuminant and the one where they are no longer illuminated, the modification of the resulting contrast for example of a change in the color of the pattern and / or its immediate environment, or the luminous intensity of the pattern and its immediate environment.

The first and second compositions may be deposited by printing or by deposition of a varnish, one covering for example entirely the other or one being arranged next to the other without covering it. One can be arranged with partial overlap only on the other.

The first and second compositions can emit by luminescence the same color, with substantially the same intensity or with different intensities.

When the first and second compositions emit the same color with substantially the same intensity, it may be advantageous to form with one of the compositions a solid and deposit the other composition in the form of at least one pattern. In the case of an at least partial superposition of the first and second compositions with the pattern which is defined by the phosphorescent composition and the flattened by the fluorescent composition, when the structure is illuminated under the predefined illuminant, the pattern can be observed in the superposition areas of the compositions because the light emitted by the solid hides the pattern, whereas when the illumination ceases, the light emitted by the phosphorescent composition makes it possible to observe the pattern, or in positive writing if the The phosphorescent composition is deposited in the form of a positive-writing imprint or a negative-writing if the phosphorescent composition is deposited as a negative-writing imprint.

By "substantially the same intensity", it should be understood that the difference in brightness is not detectable to the naked eye.

In a variant, the phosphorescent and fluorescent compositions emit the same color by luminescence but at different intensities. In this case, under the predefined illuminant, it is possible to show a positive pattern and this pattern changes to negative after extinction of the illuminant, this is the case for example if the fluorescent composition is a pattern and is a higher intensity than the composition phosphorescent which surrounds the pattern, or conversely the pattern appears negative under the illuminant and then positive after extinction of the illuminant.

Preferably, the phosphorescent composition is located on the fluorescent composition.

It is understood that the change in appearance of a pattern from positive to negative, or vice versa, means that the pattern is still discernible but that its color or its inner intensity is modified with respect to the background, that is to say by relative to the color or intensity surrounding the pattern.

The phosphorescent and luminescent compositions can still emit different colors by luminescence. In this case, it may be advantageous for the compositions to overlap at least partially. Under illumination with the predefined illuminant, it is then possible to observe in a superposition zone of the first and second compositions, a visible light of a third color, which results from the additive synthesis of the lights emitted by luminescence respectively by the phosphorescent composition and by the fluorescent composition. It may also be advantageous that in at least some areas, the compositions are not superimposed so as to allow their own colors to be observed.

The first and second compositions can be applied to the mark on the security structure, especially when they are juxtaposed. The first composition may form at least one positive pattern and the second composition may have at least one negative pattern, preferably complementary to the positive pattern, arranged at the marker. The layout of the compositions may be on the same face of a support of the structure or on either side of this support, which is then at least partially transparent.

As mentioned above, the first and second compositions can be juxtaposed and do not overlap, especially in the case of an impression at the marker.

The security structure may comprise a perforated opaque layer and the first and second compositions may be respectively on either side of this layer. The perforated opaque layer may be defined for example by at least one layer of locally demetallized metal or by a selective metallization or by a opacifying printing which is not necessarily metallic, for example comprising a black pigment or Ti0 ₂ .

The presence of the perforated opaque layer may allow, in the aperture or openings, the light emitted by the second composition to be added at least partially to the light emitted by the first, therefore to observe under the predefined illuminant a light resultant function of the luminescence colors in the presence. Moreover, the openings of the opaque openwork layer can also form patterns, which further enhances the safety of the structure.

In one exemplary embodiment, the security structure comprises a perforated opaque layer, with on one side thereof the first and second respectively fluorescent and phosphorescent compositions, and on the other side of this openwork opaque layer at least one other luminescent, phosphorescent or fluorescent composition, preferably third and fourth compositions respectively fluorescent and phosphorescent.

Numerous arrangements of the first, second, third and fourth compositions are possible, in particular to play on the nature of the compositions which are superimposed through the openings of the opaque openwork layer.

In particular, in an exemplary embodiment, the first and third compositions are shifted when the structure is observed from the first face. The second composition is also shifted with respect to the fourth. The first and third compositions may be superimposed at least partially with a lace. It may be the same for second and fourth compositions. The first and fourth compositions can be superimposed at the level of an openwork. It may be the same for second and third compositions. The first and second compositions can be juxtaposed without being superimposed; the same is true of third and fourth compositions, for example.

The first and third compositions may be the same or different, as are the second and fourth compositions. When the first and third compositions are different, as well as the second and fourth compositions, the first composition can emit by luminescence, in one example, the color of the fourth and the second composition that of the third. In an exemplary embodiment, the structure comprises two openwork opaque layers, these opaque layers can be perforated differently. The first composition may be located between the two opaque openwork layers and one of the openwork opaque layers may be between the two compositions. Moreover, the openings of the opaque openwork layer can also form patterns, which further enhances the safety of the structure.

Alternatively or in combination with a perforated opaque layer, the security structure may comprise at least one element that is a barrier to ultraviolet (UV) radiation, in particular a layer that is a barrier to UV radiation. Such a barrier layer may for example be applied by printing and / or coating. The barrier layer may be applied partially or totally to the support and / or to the fluorescent composition and / or to the phosphorescent composition.

By "barrier" is meant that the element or layer prevents the passage of UV radiation for at least a certain range of wavelength values. The "barrier" function may make it possible to avoid the effects of subtractive combination of fluorescence and phosphorescence.

The barrier layer may for example be applied by a conventional printing process, for example flexography, screen printing, inkjet or digital printing, curtain coating, roller coating, spraying or painting, among others.

The element and / or the barrier layer can be applied in the form of a pattern, for example a symbol, an alphanumeric character, a logo, among others. The pattern can be reproduced identically on the security document with the security structure.

The support of the security structure may incorporate at least one UV radiation barrier element and / or at least one UV radiation barrier layer may be applied to at least one of the faces of the support and / or at least one fluorescent and phosphorescent compositions. In particular, a first UV radiation barrier layer can be applied to the fluorescent composition and a second UV radiation barrier layer can be applied to the phosphorescent composition, the first and second layers including UV radiation barrier elements that do not overlap not. The layer and / or the UV radiation barrier element can prevent the passage of UV radiation whose wavelength is less than or equal to 400 nm.

The layer and / or the barrier element may comprise a binder chosen depending on the support, for example nitrocellulose, PVC, acrylate, among others. The layer and / or the barrier element may comprise an additive that absorbs UV radiation, for example a phosphite, triazine, benzotriazole, an ether-amine, for example Tinuvin® marketed by CIBA or Chisorb® marketed by DOUBLE. BOND, among others.

At least one of the compositions may be introduced into the security structure other than by printing. For example, at least one of the layers of the security structure is an extruded thermoplastic film or coating, which incorporates a pigment or a fluorescent or phosphorescent dye, or which is constituted by a fluorescent or phosphorescent compound.

The term "composition" should thus be understood broadly as encompassing both a solid film and a deposit having solidified, such as an ink deposit for example or a varnish.

The fluorescent composition and / or the phosphorescent composition may comprise a mixture of iridescent substances having an interferential effect.

Among the iridescent substances that can be used according to the invention, mention may be made in particular of mother-of-pearl extracts, lead salts and micas. In this respect, the preferred substances are micas, because mother-of-pearl extracts are very expensive, and lead salts imply, because of their toxicity, the respect of very strict hygiene and safety rules. Among the iridescent substances which are suitable, it is recommended micas coated with at least one metal oxide, and in particular the products marketed by Merck AG under the name Iriodine®, these products being micas coated with TiO ₂ with, where appropriate optionally, at least one other metal oxide.

The security structure may be in the form of a security element intended to be integrated in any security document, in particular a paper document comprising natural and / or synthetic fibers, in particular cellulose fibers. The security structure may advantageously be in the form of a security thread or a patch or a security film. Alternatively, the security structure can be confused with the security document, when the security document comprises a substrate on which the first and second compositions are applied directly, for example by printing, on the entire document substrate or in a strip. In the case of a security structure in the form of a wire, the latter can be integrated with a paper mass during the formation of the sheet, for example in a machine with a round shape or a flat table. In this case, the sheet may be formed so as to be equipped with windows, constituting openings which at least partially reveal the security thread or the patch.

The invention also relates to a security document incorporating a security structure as defined above.

The security structure can be observable on both sides of the document or only one of the faces, depending on the variants. The security structure may be confused with the document, for example when it comprises a paper or other substrate which is printed with the first and second compositions.

The security document can be chosen from identity documents and valuable documents, for example banknotes, show tickets or sports events, checks, identity cards, passports, transport, among others.

Preferably, each of the fluorescent and phosphorescent compositions extends over less than the entire extent of a face of the document.

The fluorescent composition preferably emits a red, green, blue or yellow color under UV illuminant at 365 nm. It is the same with the phosphorescent composition.

The security document, or the security structure that it comprises, may comprise one or more additional security elements as defined below.

Among the additional security features, some are detectable to the eye, daylight or artificial light, without the use of a particular device. These security elements comprise for example colored fibers or boards, fully or partially printed or metallized wires. These security elements are called first level. Other types of additional security elements are detectable only with a relatively simple apparatus, such as a lamp emitting in the ultraviolet (UV) or infrared (IR). 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 a lighting of a Wood lamp emitting in a wavelength of 365 nm. These security elements are said to be second level.

Other types of additional security elements 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 document. These security elements comprise, for example, tracers in the form of active materials, particles or fibers capable of generating a specific signal when these tracers are subjected to optronic, electrical, magnetic or electromagnetic excitation. These security elements are said to be third level.

The additional security element or elements present in the security document, or the security structure that it comprises, may have first, second or third level security features.

The phosphorescent composition may contain at least one phosphorescent compound chosen from ZN S DOPE zinc sulphide and a mixture of inorganic salts for example produced by GLOWBUG.

The fluorescent composition may contain at least one fluorescent compound chosen from an acrylic styrene copolymer from the company Arjowiggin and a magnesium doped with zinc sulphide from the company Glowbug.

The subject of the invention is also a process for manufacturing a safety structure as defined above, in which first and second compositions, respectively fluorescent and phosphorescent, are deposited on a support, in particular under UV illuminant at 365 nm, the deposition taking place so that the two compositions are excitable simultaneously from the same face of the structure. The deposition of the compositions can be carried out by printing, in particular a marked printing of one of the compositions with respect to the other. The deposit of the compositions can be carried out on one side of the structure or alternatively on both sides of the structure. The phosphorescent and fluorescent compositions each have a thickness of between 1 and 6 μιη, for example.

The subject of the invention is also a method of manufacturing a security document in which a security structure according to the invention, as defined above, is integrated into a paperboard substrate.

The invention also relates to a method of authenticating a document comprising a security structure as defined above, one of the first and second compositions of the document security structure forming at least one pattern, the process comprising the following steps:

the document is illuminated by the illuminant defined,

- the authenticity of the document is verified by means of the pattern which, when the illumination is extinguished by the predefined illuminant, appears or disappears or which changes appearance by passing from a positive or negative pattern or from a color to another.

In an exemplary implementation, one side of the structure under UV illuminant and after extinction of the UV illuminant is observed, and information relating to the authenticity of the document is deduced from the comparison of the observations. This comparison can be done automatically in a device responsible for this comparison, if any. In particular, under UV illuminant, both the light emitted by the fluorescent composition and the light emitted by the phosphorescent composition and / or an additive combination thereof are observed. After extinction of the UV illuminant, only the light emitted by the phosphorescent composition is observable. According to the combinations described above, it is thus possible to make appear / disappear patterns formed by the first and / or second compositions which, by comparison between the presence of UV illuminant and after its extinction, to authenticate the document.

The invention will be better understood on reading the following detailed description, nonlimiting examples of implementation thereof, and the examination of the appended drawing, in which:

FIG. 1 represents, in isolation, schematically and partially, in front view, an example of a security structure according to the invention,

FIG. 2 is a longitudinal, partial and schematic section of the security structure, FIGS. 3a and 3b show the structure of FIG. 1, respectively when observed under UV and when UV illumination ceases,

FIGS. 3c and 3d are views similar to FIGS. 3a and 3b, of an alternative embodiment,

FIGS. 4a and 4b are views similar to FIGS. 3a and 3b, of another variant embodiment,

FIGS. 5 to 12 are views similar to FIG. 2, of variant embodiments,

FIG. 13 represents an example of a security document incorporating a security structure according to the invention, and

Figure 14 is a view similar to Figure 2 of an alternative embodiment.

FIG. 1 shows an example of a security structure 10 made according to the invention.

In the example of FIG. 1, the security structure 10 is in the form of a security thread, whose width / is for example between 0.5 mm and 25 mm, this thread being intended for example for to be incorporated in a strip in a security document, then extending from one edge of this document to the opposite edge, the incorporation can be made in window (s) or on the surface.

The thickness of the structure 10 is generally, for example between 12 and 45μιη.

The invention is not limited to a security structure in wire form and the following applies to any security structure in a form other than a wire, for example patch or foil, or even a security structure constituted by the document itself.

The structure 10 comprises a support 11 which is for example a monolayer or multilayer structure, the support 11 preferably comprising at least one layer of a thermoplastic material, preferably transparent, for example PET.

The structure 10 may comprise thermo-adhesive varnishes or other surface coatings for improving its adhesion to the substrate, in particular fibrous, in which or on which it is fixed. The structure 10 may comprise elements of additional security such as magnetic or other elements, selected from those of first, second or third levels above.

The support 11 carries on one side 14 a phosphorescent composition 12 covered with a fluorescent composition 13.

The phosphorescent composition 12 is for example deposited by printing on the support 11 and forms one or more patterns 15, for example in positive write as visible in Figure 3b.

For example, the fluorescent composition 13 is deposited in the form of a solid surface covering the entire face 14 of the support 11 and the patterns 15 defined by the phosphorescent composition 12. The fluorescent composition 13 is for example deposited by printing.

The phosphorescent 12 and fluorescent compositions 13 may be chosen so as to emit by luminescence under UV excitation, at 365 mm, the same color substantially at the same intensity, so that under UV light, the structure 10 appears on the side of the face 14 of the support of substantially uniform appearance, as shown in Figure 3a, without the possibility for the observer to discern the patterns 15 formed with the phosphorescent composition 12.

After extinction of the UV illuminant, the fluorescent composition layer 13 ceases to emit and the patterns defined by the phosphorescent composition 12 appear, as illustrated in FIG. 3b. The time during which the patterns formed with the composition 12 remain visible depends on the time of remanence of the phosphorescent composition. Preferably, this period of remanence is greater than or equal to 3 seconds.

It is also possible to use phosphorescent 12 and fluorescent compositions 13 which emit different colors by luminescence. In this case, under UV illumination at 365 mm, the two compositions 12 and 13 emit different lights which, by additive synthesis where the compositions are superimposed, give patterns which appear in a first color, on a colored background. which appears from another color, which is that of fluorescence of the fluorescent composition 13 in the example illustrated in FIG. 3c.

For example, when using a fluorescent composition 13 which fluoresces blue light and a phosphorescent composition 12 which emits phosphorescence of the yellow light, under UV illumination the patterns appear in white, by additive synthesis where the compositions are superimposed, while the bottom 16 appears in blue. When the UV excitation is turned off, the patterns appear in yellow for the duration of persistence of the phosphor composition 12, as shown in FIG. 3d.

In the example of FIGS. 3a and 3b, the printing carried out with the phosphorescent composition 12 is a positive writing impression.

Without departing from the scope of the present invention, this impression can be made in negative writing, as illustrated in FIGS. 4a and 4b. The term "writing" should not be understood in a limiting sense and includes images and drawings in addition to the usual writing characters. Under UV excitation, the security structure 10 appears in a uniform color in the case of the use of phosphorescent and fluorescent compositions which emit substantially the same color with the same intensity by luminescence. In FIG. 4b, it can be seen that after extinction of the UV source, the negative writing defined by the phosphorescent composition 12 appears.

It is also possible to use phosphorescent and fluorescent compositions which emit the same color, but at different intensities. In this case, under UV and assuming that the phosphorescent composition defines positive patterns, the pattern (s) will appear with a contrast different from the background compared to the absence of UV, due to the addition of the intensities. light of the phosphorescent composition and the fluorescent composition. After extinction of the UV source, only the patterns defined by the phosphorescent composition appear positive.

In one variant, a pattern defined by the phosphorescent composition is superimposed on a solid surface of fluorescent composition, the phosphorescent composition emitting with a lower intensity than the fluorescent composition.

In the variant embodiment of FIG. 5, the fluorescent composition 13 is deposited as a flat surface on the face 14 of the support 11, whereas the phosphorescent composition 12 is deposited in the form of positive or negative write patterns, depending on the variants. . By "flattened" is meant a homogeneous deposit of sufficient extent to extend around the pattern at least.

In the variant embodiment of FIG. 6, the fluorescent composition 13 is deposited on the face 14 of the support 11 in the form of patterns, in positive or negative negative, and the phosphorescent composition 12 is deposited in the form of a solid which covers the fluorescent composition 13.

In the example of FIG. 7, the phosphorescent composition 12 is deposited in the form of a flat surface on the face 14 of the support 11, while the fluorescent composition 13 is deposited so as to define positive or negative write patterns, on the phosphorescent composition 12.

In the examples described above with reference to FIGS. 2 and 5 to 7, the phosphorescent 12 and fluorescent compositions 13 are located on the same side of the support 11.

Without departing from the scope of the present invention, the phosphorescent 12 and fluorescent compositions 13 may be disposed respectively on either side of the support 11, the fluorescent composition 13 being for example deposited on the face 14 and the phosphorescent composition 12 on the opposite face 17, as shown in Figure 8, the support 11 being at least partially transparent where the compositions 12 and 13 are superimposed and / or where it is superimposed with the composition deposited on the face 17.

FIG. 9 illustrates an embodiment variant in which the phosphorescent 12 and fluorescent compositions 13 are arranged juxtaposed and marked on the same side of the support 1 1. In this embodiment, there is no superposition of compositions 12 and 13.

In the variant embodiment of FIG. 10, the compositions 12 and 13 are respectively deposited on either side of the support 11, the face 14 of the support 11 being for example printed with the fluorescent composition 13 and the opposite face 17 with the phosphorescent composition 12. This impression can be made at the mark, as illustrated.

In the variants of FIGS. 8 and 10, the support 11 is at least partially transparent, so as to make it possible to excite the luminescence from an illumination of the structure 10 on the same side thereof, and on the same side, observe the light emitted by luminescence both by the fluorescent composition 13 and by the phosphorescent composition 12.

The support 11 may be only partially transparent, which may include opaque zones 18, for example metallizations, and apertures 19, as illustrated in FIG. 11. The compositions 12 and 13 can be printed at the mark on each of the faces of the support 11, so that on each of the faces of the structure can be observed a juxtaposition of zones respectively formed by the phosphorescent composition 12 and the fluorescent composition 13. There are thus areas where the compositions 12 or 13 located on either side of the support 11 are both superimposed at least partially with the same opaque zone 18 of the support 11, which is the case of the zones S0, S3, S6 , S9 in FIG. 11, and zones or phosphorescent compositions 13 respectively located on either side of the support 11 are superimposed with apertures 19, which is the case of the zones S1, S7. There are also areas where the fluorescent compositions 13 respectively located on either side of the support 11 are superimposed with openings 19, which is the case of S4 and S10 areas. There are also areas where the fluorescent 12 and phosphorescent compositions 13 respectively located on either side of the support 11 are superimposed, which is the case of S2, S5 and S8 zones.

Depending on the nature of the fluorescent and phosphorescent compositions, different effects can be observed. There are two following sides A and B of illumination of the structure and observation thereof, the side A being turned towards the face 14 of the support 11 and the B side opposite.

Example 1: UV illumination maintained with the phosphorescent composition 12 which emits blue light and the fluorescent composition 13 a yellow light

Visual rendering

UV Light Finder So SI S2 S3 S4 S5 S6 S7 S8 S9 S10

A A blue blue yellow yellow yellow blue blue blue yellow yellow yellow

B B yellow blue blue blue yellow yellow yellow blue blue blue yellow

A B zero blue violet zero yellow white zero blue violet zero yellow

B A zero blue white zero yellow purple zero blue white zero yellow

When the lighting is maintained on the side of the B side, which is observed from the side A, we see purple at the S2 area, which corresponds to the emission of blue light under the fluorescent composition that emits in yellow. When the lighting is maintained on the side of the side A, which is observed from the B side, we see white at the S8 area, which corresponds to the yellow light emission under the layer of phosphorescent composition which emits blue. EXAMPLE 2 After extinction of the UV illumination with the phosphorescent composition 12 which emits in yellow and the fluorescent composition 13 in blue

After Visual Rendering

extinction

UV light observer So SI S2 S3 S4 S5 S6 S7 S8 S9 S10

Zero Zero Yellow Zero Zero Zero Zero Zero Yellow Zero Yellow Zero Zero Yellow Yellow Zero Zero Zero Zero Zero Zero Yellow Zero Yellow Zero Zero Zero Yellow Zero Zero Zero Zero Zero Zero Zero Zero Zero Zero intense yellow

EXAMPLE 3 After extinguishing the UV illumination with the side of the side A, the phosphorescent composition emits yellow and the fluorescent composition emits blue and the side of the side B the phosphorescent composition emits blue and the fluorescent composition emits yellow

After Visual Rendering

extinction

Observer UV light So SI S2 S3 S4 S5 S6 S7 S8 S9 S10 A A zero zero yellow yellow yellow zero zero zero yellow yellow yellow

B B zero blue blue blue zero zero zero blue blue blue zero

A B zero blue violet zero yellow zero zero blue violet zero yellow

B A zero blue white zero yellow zero zero blue white zero yellow

FIG. 14 represents another variant embodiment of a security structure 10 according to the invention.

In this example, the support 11 is totally transparent and comprises on each of its opposite faces elements 20 which are barriers to ultraviolet (UV) radiation, applied for example in the form of layers respectively on the fluorescent composition 13 and the phosphorescent composition 12. In particular, the barrier elements 20 may be arranged on either side of the support 11 without being superimposed on each other.

Preferably, the ultraviolet radiation barrier elements are transparent to the visible radiation so that the pattern they form is visible only under a predefined excitation and invisible under visible radiation which further adds to the safety of the light. structure.

The barrier elements 20 may correspond to impressions and / or coatings produced on the support 11.

The barrier elements 20 may form a pattern, which may appear under a predefined excitation to enable the authentication of the security structure 10.

The formation of the barrier elements 20 on the support 11, in particular by printing and / or coating, can be carried out after the manufacture of the support 11 coated with the fluorescent 13 and phosphorescent compositions 12, thus making it possible to customize the security structure 10, for example under form of security thread, using the barrier elements 20 arranged in the form of patterns.

The barrier elements 20 may be printed at the mark on each of the faces of the support 11, respectively coated with the fluorescent composition 13 and the phosphorescent composition 12. There are thus areas where the compositions 12 and 13 located on either side of the 11 are superimposed on each other, which is the case of the zones S1 and S3, and areas where the compositions 12 and 13 located on either side of the support 11 are both superimposed at least partially with the same barrier element 20 , which is the case of the zones S0, S2 and S4.

Depending on the nature of the fluorescent and phosphorescent compositions, different effects can be observed. There are two following sides A and B of illumination of the structure and observation thereof, the side A being turned towards the face 14 of the support 11 and the B side opposite. EXAMPLE 4 UV Lighting Maintained with Phosphorescent Composition 12 Which Emits Blue Light and Fluorescent Composition 13 A Yellow Light

Visual rendering

Observer UV light S0 SI S2 S3 S4

A A zero yellow yellow yellow zero

B B blue white zero white blue

A B zero white zero white zero

B A zero blue zero blue zero

When the lighting is maintained on the side of the side A that is observed from the side B, or when the lighting is maintained on the side of the side B that is observed from the side A, we see white at level of the zones S1 and S3, which corresponds to a yellow light emission (or blue) under the layer of phosphorescent composition (or fluorescent) which emits blue (or yellow).

The embodiments described above can be combined with each other. In particular, the support 11 of FIG. 14 may comprise opaque zones, as previously described, for example in the form of metallizations, and / or UV radiation barrier elements arranged for example between apertures 19 as described above.

In particular, a support 11 comprising barrier elements 20 may be produced using two films, in particular polyester, the first film serving as a support for the printing and / or coating of barrier elements 20, which constitute a second film on which the fluorescent and / or phosphorescent compositions are deposited.

Alternatively, it is provided according to the invention that the security structure comprises only a first fluorescent composition and a second phosphorescent composition in the form of flattened respectively disposed on either side of the perforated support.

FIG. 12 shows an alternative embodiment in which the structure 10 comprises two transparent layers 1a and 1b. On each transparent layer 11a and 11b is deposited a partially opaque layer 18a, 19a and 18b and 19b. An adhesive 25 provides cohesion of the layers 11a, 11b and opaque openwork layers.

When the structure 10 is observed under UV illuminant from the face 14 of the layer 11a, by illuminating the structure from this face, the lights emitted by luminescence by the compositions 12 and 13 are added where the apertures 19b allow the light emitted by the fluorescent composition 13 to gain the face 14, while where this light is blocked by the opaque areas 18b, the patterns formed by the apertures 19a are only observable with the light produced by the fluorescent composition 13.

FIG. 13 shows an example of a security document 30 incorporating a security structure 10 according to the invention. This is in the form of a security thread incorporated in windows, and extending from one edge to the other of the document.

Of course, the invention is not limited to the embodiments which have just been described. In particular, it is possible to combine the particularities of embodiment of the examples which have just been described in non-illustrated variants.

The expression "having one" shall be understood as being synonymous with "having at least one", unless the opposite is specified.

Claims

A security structure (10) comprising:

at least one first fluorescent composition (13),

at least one second phosphorescent composition (12), the first and second compositions being excitable simultaneously by a predefined illuminant from the same first face (14) of the structure,

the security structure (10) being in the form of a security thread, a security film or a patch, and

the first fluorescent composition being superimposed, at least partially, on the second phosphorescent composition,

and or,

the first and second compositions being applied to the mark on the security structure.

2. Safety structure according to the preceding claim, wherein the first fluorescent composition (13) is superimposed, at least partially, to the second phosphorescent composition (12).

3. Safety structure according to one of the preceding claims, wherein the emitted lights, under illumination by the predefined illuminant, the fluorescent composition (13) and the phosphorescent composition (12) are observable from the same face of the structure (10).

4. Security structure according to any one of the preceding claims, one of the first (13) and second (12) compositions forming a solid surface which is superimposed on the other of the first and second compositions, which forms at least one pattern. (15).

5. Safety structure according to any one of the preceding claims, wherein one of the first (13) and second (12) compositions forms at least one pattern which, on extinction of the illumination by the predefined illuminant , appears or disappears, or changes appearance by moving from a positive to negative pattern or from one color to another.

6. Security structure according to any one of the preceding claims, the first (13) and second (12) compositions being deposited by printing or by depositing a varnish.

7. Security structure according to any one of the preceding claims, the first (13) and second (12) compositions emitting by luminescence the same color.

8. Safety structure according to the preceding claim, the first (13) and second (12) compositions emitting by luminescence the same color with substantially the same intensity.

9. Security structure according to claim 7, the first (13) and second (12) composition emitting by luminescence the same color with different intensities, the phosphorescent composition (12) being preferably in this case on the fluorescent composition (13). ).

10. Safety structure according to one of claims 1 to 6, the first fluorescent composition (13) emitting, under illumination by the predefined illuminant, a visible light of a first color, the second phosphorescent composition (12) emitting, under illumination by the predefined illuminant, a visible light of a second color, different from the first, and at least one superposition zone of the first and second fluorescent and phosphorescent compositions emitting, under illumination by the predefined illuminant, visible light of a third color, resulting from the additive synthesis of the first and second colors.

11. Safety structure according to any one of the preceding claims, the first (13) and second (12) compositions being applied to the mark on the security structure (10).

12. Safety structure according to the preceding claim, the first composition (13) being juxtaposed to the second composition (12).

13. Security structure according to any one of the preceding claims, the security structure comprising a perforated opaque layer (18, 19) and the first (13) and second (12) compositions lying respectively on either side of this layer.

14. Security structure according to the preceding claim, the security structure comprising two perforated opaque layers (18, 19), one of the first (13) and second (12) compositions being located between the two perforated opaque layers and one (18b, 19b) opaque opaque layers lying between the two compositions (12, 13).

15. Safety structure according to one of claims 1 to 12, the security structure having a perforated opaque layer (18, 19), with one side thereof the first (13) and second (12) compositions respectively fluorescent and phosphorescent, and on the other side of this opaque openwork layer, third and fourth compositions respectively fluorescent or phosphorescent, preferably with a superposition of at least one openwork with on the one hand one of the first and second compositions and secondly one of the third and fourth compositions.

16. Security structure according to the preceding claim, the first and third compositions being offset when the structure is observed from the first face (14).

17. Safety structure according to any one of claims 13 to 16, the structure comprising two perforated opaque layers (18a, 19a, 18b, 19b), these opaque layers being perforated differently.

18. Security structure according to any one of the preceding claims, comprising at least one element and / or a barrier layer (20) which prevents the passage of ultraviolet radiation.

19. Security structure according to the preceding claim, the element and / or the barrier layer (20) being applied to the fluorescent composition (13) and / or the phosphorescent composition (12).

20. Security structure according to claim 18 or 19, the support (1 1) of the security structure (10) incorporating at least one barrier element (20).

21. Security document incorporating a security structure according to any one of the preceding claims.

22. Security document incorporating a security structure comprising: at least one first fluorescent composition (13),

at least one second phosphorescent composition (12), the first and second compositions being excitable simultaneously by a predefined illuminant from the same first face (14) of the structure, the document comprising a papermaking substrate on which the first and second compositions are applied directly onto the entire document substrate or web, and

and or,

23. A method of authenticating a security document (30) according to the preceding claim, one of the first (13) and second (12) compositions of the security structure (10) of the document forming at least one pattern, the method comprising the following steps:

- illuminate the document with the predefined illuminant,

- verify the authenticity of the document by means of the pattern which, when the illumination is extinguished by the predefined illuminant, appears or disappears, or which changes appearance from a positive to negative pattern or from a color to another.