EP2024568B1 - Material in sheet form having a window, its manufacturing method, and security document comprising it - Google Patents

Abstract

The sheet material useful in security sheet such as a banknote or cheque and an identity document such as identity card, driving licence, passport or visa, comprises fibrous jets juxtaposed on each other of which the first jet comprises a long area of zero thickness (4) and a lack of material in an area of non-zero thickness and the second jet (5) comprises an aperture. The aperture of the second jet faces the long area of zero thickness of the first jet thus forming a window. The lack of materials extends over a width of the non-zero thickness. The sheet material useful in security sheet such as a banknote or cheque and an identity document such as identity card, driving licence, passport or visa, comprises fibrous jets juxtaposed on each other of which the first jet comprises a long area of zero thickness (4) and a lack of material in an area of non-zero thickness and the second jet (5) comprises an aperture. The aperture of the second jet faces the long area of zero thickness of the first jet thus forming a window. The lack of materials extends over a width of the non-zero thickness. The aperture of second jet has a width less than or equal to a width of the long area of zero-thickness of the first jet facing the aperture. A width of aperture of the second jet is less than 5 mm in width of the long area of zero thickness of the first jet, which is placed opposite to the aperture. The width of the zone of zero-thickness of the first jet is 10-25 mm. The first and second jets comprise a security element such as a filigree or a security thread. The security element has a width of greater than 2 mm. The aperture of the second jet has a geometric form, an alphanumeric character, a symbol or drawing. An independent claim is included for: (1) a security sheet; (2) a security document; and (3) a process of fabricating a sheet material.

Description

The present invention relates to a sheet material comprising at least one window, its manufacturing method, and a security document comprising said material.

In the prior art are known various security sheets provided with through windows or not, in particular to observe a security element placed at the window. Generally these windows are openings in the security sheet and covered with a partially transparent security element such as a foil or a patch, which may contain a security element.

We know by the patent GB 1 552 853 a bank note comprising a layer of paper within which is incorporated a security thread. The paper layer has windows on the side revealing the security thread. The windows can be made using a laser capable of removing material from the paper layer while leaving the security thread intact. The windows may, alternatively, be made mechanically, by cutting or abrasion.

It is known from the patent application EP 229 645 a security paper comprising two jets of paper between which is interposed a security thread. Holes are made on at least one of the jets of paper using reliefs on the forming web of this paper jet.

It is also known from the patent application EP 0 687 324 , a method of manufacturing a bijet paper sheet having at least one region of reduced thickness relative to the thickness of the remainder of the sheet. This gives a virtually transparent area without having to pierce the paper in this area.

We also know by the request WO 95/09274 a sheet of security paper, consisting of two layers each having a zone of zero thickness facing one another and a strip of transparent material embedded in the sheet of paper, so that the strip of material transparent is next to areas of zero thickness. This gives a transparent window.

However, the sheets thus obtained have the disadvantage of having on their faces differences in thickness, in particular thicknesses at the level of the inserted strip, so that as long as the areas of reduced or zero thickness are one area important, the sheet becomes industrially difficult to handle. Indeed, in order to be able to store or transport the sheets, they are stacked in large quantities, so that the areas of reduced thickness are brought to overlap, which leads to an imbalance of the stack.

Requirement WO 2004/001130 discloses a method for producing a paper substrate comprising bringing a security thread into contact with a paper forming web, the fabric having reliefs for producing on the substrate windows through which an edge of the thread of security is visible. This method is not suitable for incorporating into the paper substrate a safety wire having a relatively large width. Indeed, when incorporating a wide wire, visible defects such as a lack of material may appear on the surface of the paper layer.

It is also known, by patent applications EP 0 860 298 and EP 0 625 431 , a method for manufacturing a security paper in which a security thread is incorporated within a first layer of paper according to the so-called "window thread" technique described in the patent application EP 0 059 056 . This paper layer has on one side a plurality of windows revealing the security thread. In the case where the security thread has a relatively large width, especially greater than 2 mm, the first layer is then assembled with a second layer of paper to hide the defect (s).

It is also known, by the patent US 6,428,051 , a security paper comprising a fibrous layer having a window covered by a foil, the window being made by stamping the fibrous layer. The dimensions and / or shape of the window depend on the punching tool used, which requires changing the tool if it is desired to form windows of different sizes and / or shapes.

A first object of the present invention is to provide a new security sheet with a window comprising a security element, preferably quite large, and in particular having no significant extra thickness.

Another object of the present invention is to provide a new sheet material for making such a security sheet.

Thus, the invention relates to a sheet material comprising at least two fibrous juxtaposed juxtaposed one on the other, such that the first jet comprises at least one elongate zone of zero thickness and the second jet comprises at least a recess, and said at least one recess of the second jet is located opposite the at least one elongate zone of zero thickness of the first jet and forms a window.

This produces a sheet material whose structure comprises, in the superposition region of the elongate zone of the first jet and the recess of the second jet, a through window.

Each elongated zone of zero thickness of the first jet has a width preferably between 5 and 50 mm, more preferably between 10 and 25 mm.

Preferably said at least one elongate zone of zero thickness extends all along said first jet.

According to a preferred embodiment, the first jet comprises several elongate zones of zero thickness, parallel to each other, along the entire surface of the first jet so that said first jet is in the form of a succession of parallel spaced fibrous strips.

According to another embodiment of the invention, the first jet further comprises at least a lack of at least partial material, located in at least one fibrous region. In this way, a first structured stream is obtained which is particularly difficult to imitate. In addition, such a structure makes it possible, thanks to the presence of material shortcomings, to obtain tactile effects allowing recognition of the material to the touch.

According to one embodiment, the lack of material is partial, that is to say that, at the level of said gaps, the thickness of the first jet is reduced. If necessary, if the thickness of the first jet is sufficiently reduced in terms of lack of material, said gaps allow to observe the second jet by transparency.

According to another embodiment, the shortages of material are total, that is to say that, at the level of said gaps, the thickness of the first jet is zero. In this particular case, the lack of material makes it possible to directly observe the second jet.

According to one embodiment, the gaps may extend over the entire width of the fibrous region in which they are located.

In another embodiment, the material gaps do not extend the full width of the fibrous region in which they are located.

The gaps may be of different shapes, for example geometric such as circular, triangular, square, rectangular or the like.

Preferably, and in order to ensure good strength and good cohesion of the structure of the sheet material, said at least one recess of the second jet has a width less than or equal to the width of the at least one elongated zone of thickness zero from the first throw. Preferably, the width of each recess of the second jet is at least 5 mm less than the width of the elongate zone of zero thickness of the corresponding first jet.

Indeed, the first jet having an elongate zone completely devoid of fibrous material, the region surrounding this zone of zero thickness is more fragile than the region facing the second jet which contains only discrete recesses devoid of fibrous material. This is why we prefer a support whose structure is such that the edges of the first jet on either side of said elongated zone of zero thickness, rest on the second jet.

According to the envisaged subsequent use of the sheet material according to the invention, its total thickness may vary between 70 μm and 2 mm, preferably between 90 and 300 μm.

According to one embodiment of the invention, the first and second jets have equal thicknesses. According to another embodiment of the invention, the first and second jets have different thicknesses. In particular, the second jet comprising the recesses has a thickness greater than 60 microns, to avoid embrittlement of said second jet due to the presence of recesses, said jet must be relatively solid to support the first jet during the manufacture of the sheet material. The first jet, consisting of continuous strips of paper, may be finer. For example, the sheet material has a total thickness of 110 μm, the first jet being 25 μm thick and the second jet being 85 μm thick.

According to one embodiment of the invention, and in order to increase its level of security, the first and / or second stream of the sheet material comprises at least one security element. Advantageously, the security elements are placed in the thickest jet, preferably the second jet. For example, the first and / or second stream contains a watermark or security thread.

In the embodiment where the fibrous regions of the first jet include gaps, it is particularly advantageous that the second jet comprises security elements located opposite these gaps.

One of the advantages of the invention is that according to a particular embodiment, one of the jets can contain a wide security thread, that is to say whose width is greater than 2 mm, in particular between 2 and 10 mm, preferably equal to about 3mm, the zone of incorporation of this wire being covered by the other jet which thus masks the defects that the wire has created.

The recesses of the second jet may be of different geometric shapes, for example circular, rectangular, square, ovoid, triangular, hexagonal or the like. We can still consider that the recesses have the form of alphanumeric characters, symbols.

In a particular embodiment, the second jet comprises a plurality of recesses arranged so as to form a code.

The invention also relates to a security sheet comprising said sheet material and a security element in the window of said sheet material.

More specifically, according to the invention, the sheet material also comprises an at least partially transparent element, located at least partially in the at least one elongated zone of zero thickness of the first jet and facing at least one recess of the second jet.

This element can be, for example, a patch, or preferably a continuous band.

By "patch" is meant here a planar element having reduced dimensions, that is to say much smaller than those of the support on which it is affixed, in particular of square, round or oval shape. For example, said at least partially transparent element may be a patch having the shape of a square of 1.5 cm side.

According to one embodiment of the invention, the at least partially transparent element has a thickness of between 10 and 50 μm. Advantageously, this element has the same thickness as the elongated zone so that the outer surface of the first jet is flat and has no excess thickness. For example, the first jet of the sheet has a thickness of 20 microns, and a continuous strip of the same thickness is inserted into the zone of zero thickness of the first jet.

According to a particularly advantageous embodiment, the at least partially transparent element is a continuous strip whose dimensions correspond to those of the elongated zone of zero thickness of the first jet, so that said elongated zone zero thickness is fully compensated by said continuous strip. In this way, it is advantageous to obtain a security sheet whose face corresponding to the first jet is flat.

Compared to the single-jet security sheets of the prior art, the security sheet according to the invention has the advantage that, being composed of several jets, it is possible to adapt the thickness of the first jet to the thickness of the transparent element thus making it possible to obtain a flat sheet, whatever the choice of the thickness of the transparent element.

According to one embodiment of the invention, the support of the at least partially transparent element is made of a synthetic material, for example a polyester film.

According to a particularly advantageous embodiment of the invention, the at least partially transparent element comprises at least one security means. In particular, said at least partially transparent element comprises a device with variable optical effect, interferential, in particular iridescent and / or diffractive, with liquid crystals, a lens system, a hologram, a magnetic, metallic or crystalline coating, magnetic fibers, detectable tracers by magnetic resonance, tracers detectable by X-ray fluorescence, biomarkers, a varnish or an ink, luminescent tracers, in particular fluorescent tracers, photochromic, thermochromic, electroluminescent and / or piezochromic and / or tribometric compounds and / or which change color in contact with one or more predetermined products, or any other similar security means.

In another example, the at least partially transparent element comprises at least one securing means, and the total thickness of the at least partially transparent element is close to the thickness of the sheet material, said security means being placed next to a recess of the second jet. For example, can be placed in the at least partially transparent element, a security means with a thickness of 40 .mu.m.

An advantage of the security sheet according to the invention is that its structure allows it to have devices which are of greater thickness than the foils generally used in transparent windows, such as chips or tactile devices. Indeed, the foils used usually have a thickness of the order of 5 to 10 microns, while chips or tactile devices may have thicknesses of 30 to 90 microns.

According to a particular embodiment of the invention, the security sheet is such that the second jet of the sheet material comprises at least one multitone effect watermark situated opposite the at least partially transparent element of an elongate zone. zero thickness of the first jet. Such a multiton watermark is composed of light areas, ie areas of thickness less than the thickness of the remainder of the sheet, arranged so as to form a raster pattern. Such screened watermarks have been described in the patent application EP 1122360

This embodiment is particularly advantageous because it makes it possible to increase the durability of a multitone effect watermark. Indeed, multitone watermarks are security elements that are very difficult to reproduce. However, their implementation requires locally reducing the thickness of the paper sheet very importantly, which makes them sensitive to wear and generates the risk that the paper sheet is found. This risk is all the more important as documents comprising security sheets, such as banknotes, are likely to be very frequently handled. By placing the multitone watermark opposite an at least partially transparent element of an elongate zone of zero thickness of said first jet, said multitone watermark is protected and the risk of hole formation is prevented.

According to a particular embodiment, at least one means for securing the at least partially transparent element is located exactly opposite a recess of the second jet. A security sheet is thus obtained comprising at least one security means observable at a level of a window. It is also envisaged that the at least partially transparent element comprises several securing means some of which are located opposite recesses of the second jet, and others are not.

The invention also relates to a security document comprising the security sheet described above. For example, the invention relates to a means of payment such as a bank note or a check, an identity document such as an identity card, a driver's license, a passport page or a visa, or a title such as a title deed or diploma, or any other paper-based document requiring security, or secure packaging or a label.

According to a particular embodiment of the invention, the security document comprising said sheet is such that said first jet comprises at least two security elements facing at least two recesses of the second jet, said two elements of security being placed so as to be superimposed when the security document is folded, to form a security or additional information. For example, a first security element may be a lenticular network that will cover a second security element consisting of an invisible image, which will be revealed only during the superposition of the two security elements. In another example, a first security element will be a polarized filter and a second security element will be liquid crystals, forming, for example, an image revealed by the filter.

The invention also relates to a method of manufacturing a sheet material.

• réaliser un premier de jet de papier comprenant au moins une zone allongée d'épaisseur nulle par filtration d'une suspension aqueuse de fibres de cellulose sur la toile d'une première forme ronde ou d'un former,
• réaliser un second jet de papier sur la toile d'une seconde forme ronde de façon à former au moins un évidement dans ledit second jet,
• réunir les deux jets de façon à ce qu'au moins un évidement du second jet soit situé en regard de ladite au moins une zone allongée d'épaisseur nulle du premier jet et former ainsi une fenêtre,
• sécher la structure ainsi obtenue.

According to the invention, this manufacturing method comprises the following steps:

• producing a first paper jet comprising at least one elongate zone of zero thickness by filtration of an aqueous suspension of cellulose fibers on the web of a first round shape or forming a
• making a second jet of paper on the web of a second round shape so as to form at least one recess in said second jet,
• joining the two jets so that at least one recess of the second jet is located opposite said at least one elongate zone of zero thickness of the first jet and thus form a window,
• to dry the structure thus obtained.

According to a particular case of the invention, said elongated zone of zero thickness of the first jet is produced by a suppression of the filtration of the suspension on at least one zone of the fabric of said first round shape or of said former. According to a particular case of the invention, the suppression of the filtration on the first round shape or on forming it is carried out by depositing masking zones on the perimeter of said first round shape or said forming. For example, these masking zones are made by means of masks made of an adhesive film, metal, an adhesive or a varnish.

According to another particular case of the invention, the fabric of said first round shape or of forming is further provided with parts preventing filtration of the suspension so as to form total gaps in the fibrous material of the first jet. According to yet another particular case of the invention, the fabric of said first round or forming form has embossments so as to form partial gaps in the material. fibrous first throw. In these two particular cases, a sheet material having a first structured jet which is particularly difficult to reproduce is thus obtained.

According to another embodiment of the invention, said elongate zone of zero thickness of the first jet is produced by removal of material by means of a jet of pressurized fluid, in particular a jet of water or water. air, on the first jet still wet, before its assembly with the second jet.

According to one embodiment, the at least one recess on the second jet is made by embossing the fabric of the second round shape in relief, which prevents the deposition of fibrous material at the level of the endorsements.

It is also envisaged to obtain the recesses by fixing on the fabric of the second round shape of parts preventing filtration, for example a piece of metal, in particular an electrotype (ie a metal plate, usually made of bronze ), a piece of glue, or a piece of resin. The shape of the piece will thus give the shape of the recess. It is envisaged to use pieces of different shapes to make recesses of different shapes.

Finally, the recesses can be made by removal of material by means of a projection of a jet of pressurized fluid, in particular a jet of water, on the second still wet jet, before being assembled with the first jet.

• la figure 1 représente une vue transversale d'un matériau en feuille selon un mode de réalisation de l'invention
• la figure 2 représente une vue de dessus du matériau en feuille de la figure 1
• la figure 3 représente une vue de dessus d'un matériau en feuille selon un autre mode de réalisation de l'invention
• la figure 4 représente une vue transversale d'une feuille de sécurité selon l'invention, au niveau de la fenêtre
• la figure 5 représente une vue de dessus d'une feuille de sécurité servant à fabriquer un document de sécurité selon l'invention
• la figure 6 est un schéma illustrant les différentes étapes de fabrication d'un matériau en feuille selon l'invention
• la figure 7 est un schéma illustrant une des formes rondes utilisée pour la fabrication d'un matériau en feuille selon un mode de réalisation de l'invention

The invention will now be described in more detail with the aid of the accompanying drawing in which:

• the figure 1 represents a transverse view of a sheet material according to an embodiment of the invention
• the figure 2 represents a top view of the sheet material of the figure 1
• the figure 3 represents a top view of a sheet material according to another embodiment of the invention
• the figure 4 represents a transverse view of a security sheet according to the invention, at the level of the window
• the figure 5 represents a top view of a security sheet used to manufacture a security document according to the invention
• the figure 6 is a diagram illustrating the various steps of manufacturing a sheet material according to the invention
• the figure 7 is a diagram illustrating one of the round shapes used for the manufacture of a sheet material according to an embodiment of the invention

For the sake of clarity, the relative proportions of the components are not respected, and in Figures 1 to 4 In the following, there is shown a single elongate zone of zero thickness of the first jet of the sheet material, surrounded by two areas of fibrous material.

The figure 1 and the figure 2 illustrate an embodiment in which the sheet material (1) consists of two jets of fibrous material. The first fibrous material jet (2) has an alternation of elongated areas of fibrous material (3) and elongated areas of zero thickness (4). The second fibrous material jet (5) has a plurality of circular recesses (6) located opposite an elongate zone of zero thickness (4) of the first jet (2).

In particular, in the case illustrated in the Figures 1 and 2 the first and second jets have different thicknesses, the first jet (2) having a thickness of 40 μm and the second jet having a thickness of 70 μm. The second fibrous material jet (5) has a plurality of circular recesses (6) located opposite an elongate zone of zero thickness (4) of the first jet (2).

The figure 3 illustrates an embodiment in which the sheet material (1) also consists of a first jet (2) and a second jet (5) of fibrous material. The first fibrous material jet (2) comprises elongated areas of zero thickness (4), areas of fibrous material (7) having gaps (8) of rectangular shape extending over the entire width of said fibrous material areas as well as fibrous regions (3) devoid of gaps. In the same way as in the embodiment illustrated in the Figures 1 and 2 the second jet (5) has a plurality of circular recesses (6) located opposite an elongate zone of zero thickness (4) of the first jet.

The figure 4 illustrates a security sheet (9) according to the invention, comprising a sheet material as shown in FIGS. Figures 1 and 2 , and a transparent polyester film (10) inserted into the elongate region of zero thickness (4) of the first jet (2) facing the circular recesses (6) of the second jet (5). The transparent film (10) has the same width and thickness as the elongate zone of zero thickness (4) in which it is inserted, so that there is no extra thickness in this film (10) and that the face of the leaf is flat.

The figure 5 illustrates a banknote paper sheet (11) according to the invention, which comprises the security sheet (9) presented in the figure 4 and a watermark (12) made in the second jet (5).

The figure 6 is a diagram illustrating the different stages of manufacture of a sheet material such as the sheet materials presented in the Figures 1 to 3 .

The first jet (2), having elongated areas of zero thickness (4), is made from an aqueous suspension of cellulose fibers, by means of a first round shape (R1) on the fabric of which are deposited masks (M). In this way, the fibrous suspension is deposited only in regions devoid of masks (M). Thus, a first wet jet (2) is obtained consisting of an alternation of elongate areas of zero thickness (4) and areas of fibrous material.

The first jet (2) thus formed is fed to a second round shape (R2) in order to be deposited on the second fibrous jet (5) in formation. The second jet (5) is formed on the web of the second round shape, on which elements have been fixed which prevent filtration of the suspension. The elements are placed at positions marked as they form recesses (6) in correspondence with the positions of the elongate areas of zero thickness (4) of the first jet (2). There is thus obtained a second wet jet (5) made of fibrous material having recesses (6).

At the output of the second form, the first jet (2) is deposited on the second jet (5). A bijet sheet is obtained, which can then be surface treated or impregnated, for example by reinforcing the surface with PVA and / or resistance to soiling, or even improving the printability, in particular by means of a gluing press or an impregnator. This sheet is then dried and wound according to usual procedures.

The figure 7 is a diagram illustrating the first round shape (R1) used in the manufacture of a sheet material (1) according to the invention, in the particular case where the first fibrous jet (2) of said sheet material (1) comprises elongate areas of zero thickness (4) and fibrous regions comprising total material gaps (8).

The web (T) of the first round shape (R1) comprises rectangular masks in an adhesive film (M), laid on so as to extend, at regular intervals, over the entire perimeter of the round shape (R1). Thus, at the level of said masks (M), the fiber suspension is not deposited, and the first fibrous jet (2) will have areas of zero thickness (4). In the illustrated example, the first round shape (R1) further comprises rectangular pieces of metal (P) deposited on the fabric (T), between two adjacent masks (M). These parts (P) prevent the filtration of the fiber suspension, and therefore of any fibrous deposition, so that the fibrous regions (3) of the first jet (2) have a total lack of material (7).

Claims (15)

1. A material in sheet form comprising at least two fibrous plies juxtaposed on one another, a first ply comprising at least one elongate zone of zero thickness and a second ply comprising at least one recess, and said at least one recess of the second ply being situated facing said at least one elongate zone of zero thickness of the first ply, thus forming a window.
2. The material in sheet form according to the preceding claim, characterized by the fact that at least one elongate zone of zero thickness of the first ply extends over the entire length of said first ply.
3. The material in sheet form according to any preceding claim, characterized by the fact that said first ply further comprises at least one at least partial absence of material in at least one region of non-zero thickness.
4. The material in sheet form according to any one of claims 1 to 3, characterized by the fact that said one recess of the second ply has a width less than or equal to said elongate zone of zero thickness of said first ply facing said recess.
5. The material in sheet form according to any preceding claim, characterized by the fact that the width of said zone of zero thickness of the first ply is between 5 and 50 mm, preferably between 10 and 25 mm.
6. The material in sheet form according to any preceding claim, characterized by the fact that said first ply and/or said second ply comprises a security element.
7. A security sheet, characterized by the fact that it comprises a material in sheet form according to any preceding claim, and at least one at least partially transparent element in said at least one elongate zone of zero thickness of the first ply.
8. The security sheet according to claim 7, characterized by the fact that said at least partially transparent element comprises at least one security means, chosen from a variable optical effect device, an interferential, iridescent and/or diffractive device, a liquid crystal device, a system of lenses, a hologram, a magnetic, metallic or crystalline coating, magnetic fibers, tracers that can be detected by magnetic resonance, tracers that can be detected by x-ray fluorescence, biomarkers, a lacquer or ink, fluorescent tracers, or photochromic, thermochromic, electroluminescent and/or piezochromic and/or tribometric compounds and/or compounds which change color upon contact with one or more predetermined products, or a chip.
9. The security sheet according to claim 8, characterized by the fact that said security means is positioned exactly facing the at least one recess of the second ply.
10. The security sheet according to claim 7 or 8, characterized by the fact that said second ply of the material in sheet form comprises at least one watermark with a multi-tonal effect facing an at least partially transparent element of an elongate zone of zero thickness of the first ply of said material in sheet form.
11. A security document, characterized by the fact that it comprises a material in sheet form or a security sheet according to any preceding claim and by the fact that said first ply comprises at least two security elements facing at least two recesses of the second ply, said two security elements being positioned in such a way that they become superposed when the security document is folded in order to form an additional security feature or additional information.
12. A method of manufacturing a material in sheet form involving the following steps:

    - creating a first ply of paper comprising at least one elongate zone of zero thickness by filtering an aqueous suspension of cellulose fibers on the wire cloth of a first cylinder mold or of a former,

    - creating a second ply of paper on the wire cloth of a second cylinder mold in such a way as to form at least one recess in said second ply,

    - assembling the two plies in such a way that at least one recess of the second ply faces said at least one elongate zone of zero thickness of the first ply, thus forming a window,

    - drying the structure thus obtained.
13. The method of manufacture according to the preceding claim, characterized by the fact that said elongate zone of zero thickness of the first ply is created by omitting to filter the suspension over at least one zone of the wire cloth of said first cylinder mold or of said former.
14. The method of manufacturing a material in sheet form according to the preceding claim, characterized by the fact that the omission of filtration on the first cylinder mold or on the former is achieved by depositing masking zones on the perimeter of said first cylinder mold or of said former.
15. The method of manufacture according to claim 12, characterized by the fact that said elongate zone of zero thickness of the first ply is created by the removal of material by spraying a jet of pressurized fluid, before this ply is assembled with the second ply.

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