CA2761781A1 - Method of manufacturing a security element for a security document - Google Patents

Abstract

A translucent zone (Z2) is formed in the element (14) by applying a product (24) that is transparent to its substrate (12). Thus, the method comprises a step of applying a product (20) impregnating the substrate (12) on a first zone (Z1) of a first face (F1) of the substrate surrounding a second zone (Z2) devoid of the product waterproofing (20). The waterproofing product (20) prevents the impregnation of the substrate (12) by the transparentizer (24) in the first zone (Z1). The method then comprises a step of applying the transparentizer (24) to at least the second zone (Z2) so as to impregnate the substrate (12) to make it translucent in this zone (Z2). The first (Z1) and second (Z2) zones respectively form first (18) and second (22) patterns composing an image observable from the two faces (F1, F2) of the substrate (12).

Description

Method of manufacturing a security element for security document.
The present invention relates to the technical field of the elements security for document-value or security document. It applies more particularly to the manufacture of a security element transvision (in English see-through) that is to say comprising an observable image in transmitted light or even reflected light in a translucent area a substrate of the security element.
In the field of securities documents, especially banknotes bank, it is known to affix one or more security features of varied nature to protect these documents from counterfeiting. It exists different types of security features, including the elements of so-called first-level security.
Typically, a first-level security element is difficult to achieve while being easily identifiable by an audience any during a simple observation.
A transvision-type security element comprises a substrate on which additional reasons are printed on each of its faces, arranged in an area of the substantially translucent substrate, or transparent, in register with each other so as to form a composition final observable in transmitted light, even in reflected light when the area is sufficiently translucent. The translucent zone allowing the vision through also commonly referred to by the term - transvision is performed for example by local modifications of paper properties then its manufacture (fiber density, basis weight, etc.) It is in particular known to form the translucent zone on the substrate by application of r_ ~ n transparent product sari + e substrate

2 a translucent zone is formed by application of a composition transparentizing.
The disadvantage of this technique is that the wetting of the substrate gives a greasy, sticky appearance that is detrimental to the aesthetics of safety even after drying.
In addition, the transparency composition tends to migrate to the substrate surface which gives the translucent area a deformed appearance and irregular looking like an unwanted spot.
The object of the invention is in particular to remedy this drawback by providing a method of manufacturing a security element comprising a substrate with a particularly aesthetic translucent zone, while being very simple and inexpensive to implement.
For this purpose, the subject of the invention is a method of manufacturing a security element for security document, the security element comprising a substrate delimiting first and second opposite faces, in which a translucent zone is formed in the substrate by application a substrate-transparent product, characterized in that, to form this translucent zone, the method comprises:
a first step of applying a waterproofing product substrate on a first zone of the first face surrounding a second area of the first side devoid of this product permeabilizer, the waterproofing product preventing impregnation of the substrate by the transparent product in the first zone device and then a second step of applying the transparent product to least the second zone to impregnate Io substrate for the make translucent in this zorne the first and second zones forming respectively first and second patterns making up a image observable from both sides of the substrate, I._7 prerPie, the zone forms the border ooeriphCirque auto +. # Of the

3 around the second zone. By transparency, we mean who makes translucent, even transparent.
Of course, the first zone may include nestings more or less complex in the second zone, the important thing being that the contour of any part of the second zone is delimited by the first zoned.
The outline of the translucent area can then be clearly delimited thanks to the presence of the first area that surrounds the translucent area and which prevents, thanks to its previously applied waterproofing product, a part of the transparent product to extend beyond the limits of second predefined area and on the other hand to the transparent product to migrate into the substrate to the right of the first zone. This has the effect of reducing the appearance diffuse of the task.
By waterproofing product is meant a product impervious to a liquid at least for a predefined period. So when the product is applied to an area of the substrate covered by the product waterproofing, the transparent product does not penetrate into the substrate at right of this area for a predefined period beyond which effectiveness waterproofing product may decrease. It is then necessary to dry the transparent product before the end of this predefined period so as to avoid late impregnation of the transparent product in the substrate.
Preferably, the waterproofing product is an opaque product at light and so is said covering product.
In this case, the two zones make up an image contrasted thanks to the presence of two distinct products covering and transparentisant. image observed in reflected or transmitted light from of on the first side, includes a dark area corresponding to the main zone including the covering product and a clear area corresponding to the area translucent comprising the transparent product, hn observing the image from the second side in light , n i i f f f réfléch réfléch réfléch réfléch réfléch réfléch réfléch réfléch réfléch réfléch réfléch réfléch réfléch réfléch réfléch réfléch réfléch réfléch

4 So, the second pattern is perfectly observable from the second face in transmitted or reflected light. This second reason is detaches in particular the uniform substrate by its diaphanous appearance linked to impregnation of the transparent product in the substrate.
On the contrary, the first motif is difficult to observe from the second face since the substrate appears more opaque on the second side to the right of this zone because of the presence of the product covering the first face, especially by observation in transmitted light.
The observable image from the second face thus corresponds to negative of the observable image from the first observation face, and this is clearly visible by observation in transmitted light.
As a result, the first and second zones defining between them a contrast in the image that reverses according to the face of observation of the image.
Indeed, while by observing the image from the first face (so-called front), the first pattern is more visible than the second pattern, this contrast is reversed by observation from the second face (called back), since from this face the first motif is almost invisible (because of the opacity of the substrate in this area) while the second pattern is at less as visible as by observation from the first face (thanks to the impregnation of the substrate throughout its thickness).
Preferably, the waterproofing product is a usable ink in offset printing, screen printing, flexography, letterpress, rotogravure and Intaglio Preferably. the waterproofing product is a chosen ink F) Armi A wrinkle created, an ink effect ept that variable. an ink magnetically variable optical effect, a metal effect ink such as for example, silver ink and liquid crystal ink.
Preferably. the transparent product is a strong ink wetting power comprising for example del r ~ nomere; h sse ter -, c31 () 11 Sir.

Of course, the effectiveness of the impregnation of the substrate by the product depends not only on the characteristics of the transparent product (of its wettability, its viscosity, the amount deposited and the duration separating the application of the product and its drying) but also of the nature

5 of the substrate (fiber impregnation capacity, basis weight, calendering of the surface, porosity, etc.).
Preferably, the transparent product comprises tracers of for example, fluorescent particles, reaction at a predefined wavelength and / or thermochromic particles.
Thus, thanks to the presence of such particles, optical effects and additional security can be obtained.
Preferably, the method comprises a step of drying the irradiation-transparent product with ultraviolet light purple or infrared or by emitting a flow of hot air. Thus, thanks to drying, the transparent product is attached to the substrate.
Preferably, the substrate is made of a material comprising essentially paper made from natural and / or synthetic fibers, porous paper and / or cardboard paper.
In addition, possibly and in one embodiment of the invention, the method comprises an intaglio printing step with a non-penetrating or ink-free transparent ink to form a tactile mark in the second zone.
This makes it possible to add a complementary effect to the composite image first and second patterns, thereby producing tactile sensations.
The intaglio print with ink makes it possible to form a more pronounced relief detectable to the touch unlike the case where the substrate is difficult deformable. [.] in the case of a deformable substrate. a size impression-fresh without ink (commonly referred to as dry stamp) may be sufficient for form a pronounced relief detectable to the touch.

I) e prefel "ente r + ink" ansparente non r) enotr "ir1fe ^ r1j" 7 ~ 7f "n ~?

6 of a reaction type at a predefined wavelength and / or particles thermochromic.
In a manner known per se, the fluorescent particles react to exposure to ultraviolet light by producing a reaction short-lived fluorescence during this exposure. In a classic way, the thermochromic particles have a color that varies reversibly depending on the temperature.
Preferably, the transparent product is applied to the substrate by screen printing, flexography, offset, intaglio printing, typography and or gravure.
In addition, preferably, the method comprises a step of formation of a third image pattern on the second face of the substrate in locating with respect to the second area so that it is observable from the first side by translucency of the second zone. In variant, the third pattern 26 may not be formed in registration but in free positioning compared to other reasons.
Preferably, the third pattern completes the first and second patterns to form a final image observable from both sides in transmitted light, or even reflected light.
In addition, in one embodiment of the invention, the third pattern includes a message coded on the second face and the second zone includes means for decoding the message capable of revealing the message encoded by observation from the first side at least in light transmitted.
Preferably, the second inner zone is made sufficiently translucent to allow observation of light reflected from the del a races of the third m-votive rinse substrate extending over the other faces in locating with respect to the inner zone.
Thus, 1 transvision ettet can also be observed in light thoughtful and this facilitates the verification of the docr. d: É
creed,

7 The subject of the invention is also a safety element, characterized in that it is obtained from a manufacturing method according to the invention.
The invention finally relates to a security document, such as a ticket bank, comprising a security element, characterized in that the security element is according to the invention.
Other features and advantages of the invention will become apparent light of the description which follows, made with reference to the accompanying drawings in which FIGS. 1A and 1B respectively represent top views and from below a security document including an element of security according to a first embodiment of the invention;
FIGS. 2A and 2B respectively represent top views and from below a security document including an element of according to a second embodiment of the invention according to the section 3-3 of Figure 2A;
FIG. 3 represents a sectional view of the security document of Figures 2A and 2B;
FIGS. 4A and 4B represent respectively views from above and from below a security document including an element of security according to a third embodiment;
FIGS. 5A and 5B show respectively views from above and from below a security document including an element of security according to a fourth embodiment;
FIGS. 5A and 5B show respectively views from above and from below a security document including an element of security according to a fifth embodiment in observation orthogonal to plan, security document and figures 6C and 6D represent the same views as FIGS. 6A and 6B but in grazing observation - Figures, 7 to 10 illustrate stages of production or production not

8 FIGS. 1A and 1B show a security document comprising a security element according to the first embodiment. This security document is designated by the general reference 10.
The security document 10 comprises a substrate 12 delimiting first F1 and second F2 opposite sides. In this example, the document Security 10 is a page of a passport. Alternatively, the document Security 10 may be a bank note or other valuable document.
This security document 10 comprises a security element 14 formed on a portion of the substrate 12. This security element 14 comprises a first zone Z1 forming a first pattern 18 extending on the first face F1 of the substrate 12. This first pattern 18 is formed by a deposit of a product 20. The waterproofing product 20 is preferably also opaque to light and is designated in the following description by covering product 20. Of course, alternatively, the waterproofing product 20 may be more or less opaque, even translucent, without it framework of the invention.
For example, the covering product 20 is applied to the substrate 12 by screen printing, flexography, offset and / or intaglio printing, by typography and / or heliography. Thus, preferably, the product covering 20 is an ink that can be used in offset printing, flexography, screen printing, typography, gravure and intaglio.
In addition, the covering product 20 is preferably a chosen ink among an iridescent ink, a variable optical effect ink, an ink magnetic variable optical effect, a metallic effect ink, such as a 5 silver ink and liquid crystal ink.
Otherwise. the security element '.4 includes a second category, Z2 form a second pattern 22 and devoid of the product covering 20. This Z2 area is translucent. that is, it lets the light through.
This second zone Z2 is formed by application of a product transparentizing 24 ventueflement. fe transparent product '' 4 pst applied

9 Indeed, more particularly, the covering product 20 prevents the impregnation of the substrate 12 with the transparent product 24 in the first zone Z1.
For example, the transparent product 24 is a strong ink wetting power comprising low surface tension monomers, resins and / or photoinitiators or acrylic ink. So, by example, a transparent product which may be suitable comprises a composition such as than that described in GB 1,489,084.
Preferably, the transparent product 24 is applied by serigraphy. Alternatively, the transparent product 24 can be applied by any other known printing technique.
The first zone Z1 is subsequently called peripheral as opposed to the second zone Z2, called internal, because the zone Z1 surrounds said second zone Z2, called internal.
In this first embodiment, the first zone Z1 has a oval general shape and the second zone Z2 has a general shape of flower.
In the example described, the security element 14 comprises a third pattern 26 printed on the second face F2 of the substrate 12. This third pattern 26 completes the image formed by the first 18 and second 22 reasons. The third pattern 26 extends over a third zone Z3 of the substrate 12.
This third pattern 26 is printed in location on the outside with respect to first 18 and second 22 patterns.
The image obtained is observable from the two faces FI, F2 of substrate 12 in transmitted light and at least partially in light reflected.
Preferably, the second zone Z2 is made sufficiently ranslucide to allow observation in reflected light from games faces r I 1021 .Thus, the inner zone Z2 is sufficiently translucent to allow an observation of the third pattern 26 in reflected light and no longer light transmitted from the first face Fg (as n ela WO 2010/1309

10 PCT / FR2010 / 050786 Indeed, the first pattern 18 of the image resulting from the application of the covering product 20 is observable without difficulty in reflected light at go of the first face FI but is more difficult to observe in light reflected from the second face F2.
Thus, the contrast between a zone of the substrate 12 devoid of any product and Z1 zone is relatively small because the substrate 12 outside of the Zone Z2 is relatively opaque in observation from the face F2.
The first and second zones Z1, Z2 define between them a contrast in the image which is reversed according to the observation face F1, 10 of the image transmitted light, or even reflected light in the where the second inner zone Z2 is sufficiently translucent.
However, while the contrast is relatively sharp in observation by light transmitted from the two faces F1, F2, the latter is less visible when one observes the image from the second face F2 (ie say the F2 side not bearing the covering product) in reflected light.
FIGS. 2A to 6B show second to fifth embodiments of a security document 10 comprising an element of 14. In these embodiments, elements similar to the first embodiment have identical references in the figures and in the description. These different embodiments make it possible to increase the security level of the document with the security element.
In the second embodiment illustrated by FIGS. 2A and 2B, the first zone Z1 also partly extends to the center of the second zone Z2. The first zone Z1 follows the contours of the second zone Z2.
Moreover, in this embodiment. the third reason 26 is Partly in the second translucent zone Z2.
Preferably, the second zone Z2 is made sufficiently franslucide to allow observation in reflected light from the face Fi of a third pattern 26 extending on the face F2 in registration with Outside and inside of the second zone?

11 FIG. 3 shows the layers of material applied on the substrate 12 to form the zones Z1, Z2 and M. Ainsi, the zone Z1 comprises a product layer covering 20, zone Z2 comprises a layer of transparent product 22 which impregnates the substrate 12 on its entire thickness without impregnating the substrate 12 to the zone Z1 right.
Finally, zone Z3 also includes a product layer 28 such as an ink.
In the third embodiment illustrated by FIGS. 4A, 4B, the security document 10 is a bank note. Security Element 14 a for example a rectangular general shape forming a vertical band in the ticket 10.
The security element 14 comprises a first peripheral zone Z1 in general band shape and a second translucent inner Z2 area delimiting a second pattern 22. In the example illustrated in the figures, the second pattern 22 includes twice the inverse number `100 'and a sun stylized. Zone Z3 represents a third pattern 26 and includes the number 100 ' in the place where the central '0' figure forms a sun that completes in locating the sun of the F1 face of the substrate 12.
In the fourth embodiment illustrated by FIGS. 5A, 5B, the third pattern 26 includes a coded message 30 on the second face F2 and the second zone Z2 comprises means 32 for decoding the message able to reveal the coded message by observation from the first face F1 at least in transmitted light.
In this example, we see that the third pattern 26 is a message scrambled - <OA>, hardly noticeable! he naked in observation in light 2.5 transmitted etiou reflected from the second face F2 of the substrate 12.
In However. by observation from the first FI face thanks to 3. Ui.
presence decoding means in zone Z2, braiding 30 is connected by transvision.
The message 30 is encoded for example by a known technique of Dégéggraphie qt, i consist in coding information clans in fcnd

12 The decoding means 32 comprise, for example, lines modulated at a frequency substantially equal to the concealment frequency of the message. Preferably, the lines are printed and / or formed in relief.
In this illustrated example, the decoding means 32 comprise a relief 31 forming a repetition of lines of predefined height and of frequency substantially identical to that used to code the message.
This relief 31 is for example made by the conventional technique of dry stamp.
The dry stamp is made in registration with respect to printing offset of the face F2 of the substrate 12 and forms a decoding pattern steganographic, revealing the hidden data on the second face F2 of the substrate 12.
For example, the relief 31 is made by intaglio printing with a non-penetrating transparent ink to also form a tactile mark in the second zone Z2.
The non-penetrating transparent ink preferably comprises tracers, for example fluorescent particles, particles of a reaction type at a predefined wavelength and / or particles thermochromic.
FIGS. 6A and 6B show a security document 10 comprising a security element 14 according to a fifth embodiment of the invention.
In this fifth embodiment, the third pattern 26 comprises at least one latent image 34 on the first face F1, in particular in the first zone Z1. We see in particular that the letters B and C form first 34A and second 34B latent images.
The third pattern 26 includes a third still image 34C
formed on the second face F2, in the second zone Z2. These images Latents 34A-34C are formed by deformation with or without ink.
In a conventional manner, a latent image is obtained by printing in soft talon and is visible only under one. ert ~ ine inclinaisnr1 dlu djocu) ment, naar

13 In the example described, the latent images are produced by a relief printing process. The security element 14 comprises a first network of lines 36 extending in a predefined orientation and a second network of lines 38 extending in another orientation, for example oblique (as in the example shown) or perpendicular, thus forming a net break between the two networks 36 and 38.
For example, the second network 38 forms a pattern of the latent image may include information (in this example, information includes letters B and C) and the first network 36 forms the background of the image the tent.
Thus, as can be seen in Figures 6A and 6B, in orthogonal observation we do not see the latent image but in observation grazing as illustrated in FIGS. 6C and 6D, the pattern of the latent image appears clearly.
We will now describe the main steps of a process of manufacture of a security document 10 comprising a security element 14 with reference to Figures 7 to 10.
The reasons for the security element 14 illustrated by these figures have different shapes from the patterns of the other embodiments but the manufacturing process is applicable for the realization of the element of security of any of the previously described embodiments.
Initially and optionally, the third pattern 26 is formed.
the image delimited by the third zone Z3 on the second face F2 of the substrate This third zone Z3 is formed by flexographic printing, intaglio, silkscreen. typography or gravure. but preferably in ) Ffset.
t_e third n otrf 26 represents a sun written in urge star Le-third pattern can be printed in many colors.
THEN in a second step illustrated in Figure 8, ZI zone form on the first face FI of the substrate 12 by jpplic, a -ion s., r 1a

14 In a third step illustrated in FIG.
of the transparent product 24 on at least the inner zone Z2 so as to impregnate the substrate 12 to make it translucent in this area.
The first Z1 and second Z2 zones respectively form first 18 and second 22 patterns complementing each other to form an image observable at least by transmitted light and preferably by light reflected from the two faces F1, F2 of the substrate 12.
As the zone Zi includes covering product 20 which prevents the impregnation of the substrate 12 by the transparent product 24, it is possible to overflow substantially on the first zone Z1 during this application without this overflow being visible.
During this step, when the transparent product 24 has Impregnated the substrate 12 over its entire thickness, the third pattern 26 appears in transmitted light, or even in reflected light by observation from of the first F1 face.
The method further comprises a step of drying the product transparentizer 24 by irradiation irradiation with spectrum light ultraviolet or infrared or by emission of a hot air flow.
Applying the transparent product 24 by overflowing on the first zone Z1 only slightly modifies the appearance of the product covering 18 on the first F1 face.
Indeed, it is possible to observe a slight change in appearance golden product covering 18 if the latter is an iridescent ink by example.
Thus, it is possible that the application of the transparent product 24 on the product covering 20 slightly tarnishes its golden appearance. This allows also to produce further new optical effects.
It is understood that the embodiments that have just been described are not limiting in nature and that they will be able to receive all a desirable change without going out of the way;

In particular, it would be consistent with the invention to apply the product transparent by any other printing technique than those mentioned preferentially in the description.

Claims (17)

A method of manufacturing a security element (14) for security document (10), the security element (14) comprising a substrate (12) delimiting first (F1) and second (F2) opposite faces, wherein a translucent zone (Z2) is formed in the substrate (12) by application of a product (24) which is transparent to the substrate (12), characterized in that forming this translucent zone (Z2), the method comprises:
a first step of applying a product (20) which impregnates the substrate (12) on a first zone (Z1) of the first face (F1) surrounding a second zone (Z2) of the first face (F1), devoid of of this waterproofing product (20), the waterproofing product (20) preventing the impregnation of the substrate (12) with the transparent product (24) in the first zone (Z1), then a second step of applying the transparent product (24) to the least the second zone so as to impregnate the substrate (12) for the make translucent in this zone (Z2), the first (Z1) and second (Z2) areas forming respectively first (18) and second (22) patterns composing an observable image from both sides (F1, F2) substrate (12). 2. Method according to the preceding claim, wherein the product waterproofing is opaque to light. The method of claim 1 or 2, wherein the product impenerabilizer (20) is a usable ink, in offset printing, Elexography, screen printing. typography, gravure and intaglio 4. Method according to any one of the preceding claims, wherein the waterproofing product (20) is an ink selected from iridescent ink, a variable optical effect ink, an effect ink optical magnetic variable, a metallic effect ink and a crystal ink liquids. 5. Method according to any one of the preceding claims, wherein the transparent product (24) is a high power ink wetting agent comprising, for example, monomers with a low surface tension, resins and / or photoinitiators or acrylic ink. 6. Method according to the preceding claim, wherein the product (24) comprises security tracers, for example fluorescent particles, reaction-type particles to a length predefined wave and / or thermochromic particles. 7. Method according to any one of the preceding claims, comprising a step of drying the transparent product (24) by irradiation with ultraviolet or infrared spectrum light or program a hot air flow. 8. Process according to any one of the preceding claims, comprising an intaglio printing step with a transparent ink non-penetrating or inkless to form a tactile landmark in the second zone (Z2). 9. Method according to the preceding claim, wherein the ink non-penetrating transparency includes security tracers, for example fluorescent particles, reaction-type particles to a length predefined wave and / or thermochromic particles. 10. Process according to any one of the preceding claims, in which the transparentizer (24) is applied to the substrate (12) by silkscreen, flexo, offset, intaglio, letterpress and / or gravure. 11. Method according to any one of the preceding claims, comprising a step of forming a third pattern (26) of the image on the second face (F2) in register with respect to the second zone (Z2) of so that it is observable from the first (F1) by translucency of the second zone (Z2). 12. Method according to the preceding claim, wherein the third reason (26) completes the first (18) and second (22) reasons for form a final image observable from both sides (F1, F2). 13. Method according to the preceding claim, wherein the third pattern (26) includes an encoded message (30) on the second face (F2) and the second zone (Z2) comprises means (32) for decoding the message able to reveal the coded message (30) by observation from the first face (F1) at least in transmitted light. 14. Process according to any one of the preceding claims, wherein the substrate (12) is made of a material comprising essentially paper made from natural and / or synthetic fibers, porous paper and / or cardboard paper. 15. Process according to any one of the preceding claims, wherein the second zone (Z2) is made sufficiently translucent to allow observation in reflected light from one of the faces (F1) a third pattern (26) extending on the other of the faces (F2) in registration by compared to the second zone (Z2). 16. Security element (14), characterized in that it is obtained from a manufacturing method according to any of the claims preceding. 17. Security document (10), such as a bank note, comprising a security element (14), characterized in that the element of security (14) is according to the preceding claim.