EP2822764A1

EP2822764A1 - Method and device for the secure protection of official documents by means of a transparent film having a single continuous thermoplastic layer

Info

Publication number: EP2822764A1
Application number: EP13711092.0A
Authority: EP
Inventors: Laurence Bes; Eric Philippe; Anthony Gallo
Original assignee: Fasver SAS
Current assignee: Fasver SAS
Priority date: 2012-03-05
Filing date: 2013-03-05
Publication date: 2015-01-14
Anticipated expiration: 2033-03-05
Also published as: WO2013132186A1; EP2822764B1; HK1205483A1; FR2987577B1; FR2987577A1

Abstract

The invention relates to a method for the secure protection of a surface portion (5) of an official document (9) in which a transparent security film is heat-transferred onto said surface portion. The security film includes a single continuous layer (2) which determines the format thereof and has a thickness of 5 μm to 25 μm, made up of a thermoplastic resin having a glass-transition temperature of 30 °C to 120 °C. A protective device supporting said security film is laminated at a lamination temperature higher than said glass-transition temperature in order to perform the transfer thereof.

Description

METHOD AND DEVICE FOR SECURELY PROTECTING

OFFICIAL DOCUMENTS USING A TRANSPARENT FILM TO

SINGLE THERMOPLASTIC CONTINUOUS LAYER

The invention relates to a method and a device for the secure protection of a surface portion of an official document formed of a fibrous material by hot transfer of a transparent security film. It extends to an official document thus protected.

Various devices and methods for the protection of official documents in fibrous material are already known (identity documents (identity card, passport, driving license ...), gray cards, diplomas, contracts, fiduciary documents, banking document, certificates, tickets ...) against falsification attempts and / or counterfeits and / or for authentication and / or against aggressive external environments. In particular, it is appropriate to protect variable inscriptions and / or common marks or inscriptions (in particular marks or inscriptions made with patterns or inks of safety such as photoluminescent inks under ultraviolet, iridescent inks, holograms ...) carried by these official documents. It should be noted in this respect that the invention does not relate to the manufacture of cards such as bank cards made of non-fibrous polymeric materials that do not pose the same problems.

Among the known security protection solutions, one of the most commonly used since EP-0271941 and US-5232527 is to apply by heat transfer on the surface to be protected a thin transparent adhesive film of multilayer polyurethane, this security film can incorporate various security functions such as embossed and / or metallized and / or holographic markings or impressions (FR 2897556), patterns preventing reproduction by optical scanning, patterns visible only under certain lighting conditions (WO 0024587, FR 2834484), patterns whose appearance varies according to the viewing angle, iridescent patterns, interferential pigment patterns, weakened areas (FR 2862906) ... All these known security films of official documents comprise at least one layer of varnish (usually of type bi-component, eg polyurethane), and preferably in general a plurality of lacquer layers, and at least one adhesive layer which may be a cold pressure sensitive adhesive or a heat-activatable adhesive. They are carried by a lamination support so as to form a transfer, and, during the hot lamination of this transfer on an official document to be protected, the adhesive layer is applied to the surface portion of the official document to glue. on the latter with an adhesive power greater than the adhesive power of the film on the lamination support, so that the latter can then be detached.

These devices and known security protection methods are generally satisfactory, but the inventors have determined that they have the disadvantage not only of being relatively complex and expensive to manufacture (and in particular are most often incompatible with continuous manufacture ), but also not to optimize the security film to the nature of the portion of the surface to be protected (which can vary from a simple paper, to synthetic papers or other more or less complex materials) and / or the mechanical and / or optical and / or chemical characteristics sought. Indeed, the adhesive layer must itself be compatible on the one hand with the adjacent layers of varnish of the security film, on the other hand with the material of the surface portion to be protected and with the possible inscriptions that she wears. It turns out in practice that it is not always possible to use one or other of these known security films according to the official document to be protected.

The invention therefore aims to overcome these drawbacks by proposing a method and a safety protection device that can be more easily adapted and optimized according to the nature of the surface portion to be protected and according to the mechanical and / or optical and / or chemical characteristics sought. in terms of protection.

The invention also aims to achieve this goal at a lower cost, in a simple, reliable and reproducible manner, in particular by making it possible to ensure a quality of production and quality of application of the security film on the document. The invention therefore relates to a method for the secure protection of a surface portion of an official document made of a fibrous material, in which:

a device for protecting by hot transfer of a transparent security film extending in a format adapted to that of said surface portion and carried by a support film adapted to allow the hot transfer of said security film onto a film. said surface portion by lamination of the protective device on said surface portion,

said film of security is transferred to said surface portion, characterized in that:

a protection device is chosen whose said security film comprises a single continuous layer determining said format and having a thickness of between 5 μπι and 25 μπι consisting of a thermoplastic resin having a glass transition temperature of between 30 ° C. and 120 ° C. ° C - in particular between 35 ° C and 80 ° C-,

said protective device is rolled onto said surface portion by applying said security film directly to said surface portion at a lamination temperature greater than said glass transition temperature so as to transfer said security film to said portion of said surface portion; area.

The invention extends to a device for implementing a method according to the invention. It therefore also relates to a device for the safe protection by heat transfer on an official document surface portion formed of a fibrous material, comprising:

a transparent security film extending in a format adapted to that of said surface portion,

a support film carrying said security film and adapted to allow the hot transfer of said security film to said surface portion by lamination of the protective device on said surface portion, characterized in that: said security film comprises a single continuous layer determining said format and having a thickness of between 5 μπι and 25 μπι consisting of a thermoplastic resin having a glass transition temperature of between 30 ° C. and 120 ° C. in particular between 35 ° C. C and 80 ° C,

said security film is directly applied to said surface portion.

Surprisingly, the inventors have found that the fact of using a single layer of thermoplastic resin as mentioned above to constitute mainly the security film, allows on the one hand to obtain an equally effective safety protection, and even better in many cases, than previously known multilayer films, on the other hand allows to vary in a wide range of variation the chemical nature of the security film, and thus to make it chemically perfectly compatible and optimized with different fibrous materials constitutive documents. Also, it is possible with such a single layer to control the mechanical characteristics, in particular in terms of flexibility, surface hardness, mechanical cohesion ... the surface chemical resistance, the adhesion power on the official document, the surface appearance that can be more or less matte or shiny.

Moreover, the manufacturing method of the device and its cost are reduced. In particular, a protection device according to the invention can be easily manufactured in a continuous process, because of the small number of printing steps that it requires, each printing step being simple, not subject to constraints. of precise drying or crosslinking, the support film may be chosen to be itself compatible with such continuous manufacture.

Also, the operation of transferring the security film according to the invention to an official document is facilitated, simpler, and in practice subject to fewer constraints than with a known multilayer film whose adhesive is specific.

Furthermore, it turns out that the support film carrying the security film may itself be subject to different variants, and may consist of a common carrier film and inexpensive, in one thickness, may be lacking silicone or detachment layer, unlike films multilayer known previously which can most often be printed on very specific and expensive media. In addition, the invention even makes it possible to apply a security impression interposed between the security film and the support film, that is to say, exposed on the outer face of the security film after transfer of the latter on a document official, this security impression having a considerably improved optical appearance, especially when it is made with iridescent ink and / or interferential pigments and / or photochromic pigments and / or thermochromic pigments, while having an excellent mechanical strength in terms of being embedded in the thickness of said thermoplastic single layer and intimately bonded thereto by the very fact of the lamination step. In particular, it should be noted that the invention makes it easy to choose compositions of security ink and thermoplastic resin perfectly compatible with each other, in particular belonging to the same chemical family and / or similar chemical natures and / or including same solvents. In particular, the thermoplastic resin constituting said single continuous layer of the security film may be chosen from the group of vinyl thermoplastic resins, polyester thermoplastic resins, thermoplastic polyamide resins and mixtures thereof.

Also, such a thermoplastic resin may comprise one or more solvents that can be chosen from a wide range of solvents of different properties and / or natures, in particular depending on the nature of the official document to be protected.

Advantageously and according to the invention, said protective device is laminated at a higher lamination temperature of 30 ° to 100 ° C to the glass transition temperature of said thermoplastic resin. The maximum value of the lamination temperature is limited by the strength of the support film, the latter must not be damaged or begun to melt in order to be detached after lamination, and by that of the surface portion of the official document which must not no longer be damaged. Thus, the lamination temperature must in particular be less than the glass transition temperature of the support film when the latter is thermoplastic. In addition, in a method according to the invention, if said surface portion of the official document is itself also thermoplastic, a lamination temperature is chosen that is lower than the glass transition temperature of said surface portion. It should be noted, however, that it may be envisaged to choose a lamination temperature which is of the order of the glass transition temperature of said surface portion so as to favor an intimate connection of said continuous layer of the security film with said surface portion during this lamination step, if the other characteristics of said surface portion of the official document allow it, for example if it is compatible with the presence of variable or common inscriptions on this portion of surface.

Furthermore, advantageously, and according to the invention, a protective device is chosen in which said single continuous layer of the security film consists of a vinyl thermoplastic resin. In particular, such a vinyl thermoplastic resin is perfectly transparent not only in the visible range, but also in the entire ultraviolet range, which is a considerable advantage when photoluminescent inscriptions are carried by the official document.

Furthermore, advantageously, and according to the invention, a protective device is chosen in which said single continuous layer of the security film consists of a thermoplastic resin whose molecular weight is between 20,000 g / mol and 100,000 g / mol. . In this way, it is particularly avoided that the security film has a residual adhesive capacity (tac) after laying. It should be noted that the known adhesive compositions are generally formed of resin whose molecular weight is between 5000 g / mol and 10 000 g / mol. The thermoplastic resin constituting the single layer of the security film according to the invention is therefore different from known adhesive compositions.

More particularly, this vinyl thermoplastic resin constituting said single continuous layer of the security film according to the invention is chosen from the group formed of acrylic polymers and acrylic copolymers whose molecular weight is between 20,000 g / mol and 100,000 g / m 2. mol, especially chosen from the group consisting of the following polymeric materials: methyl methacrylate-ethyl acrylate, butyl methacrylate-methyl methacrylate, ethyl acrylate-ethyl methacrylate-methyl methacrylate, butyl-styrene methacrylate, methyl methacrylate and butyl methacrylate.

In addition, advantageously and according to the invention the security film comprises at least one inscription printed on at least one of its faces with the aid of an ink composition -particularly a composition of security ink-. Advantageously and according to the invention, an ink composition chemically compatible with said thermoplastic resin is chosen. An ink composition is composed of a coloring agent such as a pigment or a colorant, a binder and a solvent medium (which disappears on drying). Advantageously and according to the invention, use is made of an ink composition comprising a vinyl binder, in particular an acrylic binder. Advantageously and according to the invention, said security film carries at least one inscription formed of a security ink composition chosen from the group consisting of photoluminescent inks - especially in ultraviolet light -, fluorescent inks, photochromic inks, thermochromic inks, iridescent inks, interferential pigment inks, soluble dye inks, and soluble binder inks. Advantageously and according to the invention said security film also bears at least one security mark, in particular chosen from the group of holographic marks and metallised marks (that is to say formed from at least one impression of a ink producing a metallic effect and / or incorporating metallic particles and / or a metal layer).

The support film receiving the security film must allow on the one hand the application of said single continuous layer by printing of the latter on the support film, and possibly printing any inscriptions on the support film before that of said single continuous layer, but also its detachment of the security film after the lamination step on said surface portion of an official document. In practice, advantageously and according to the invention, the support film has a receiving face of the non-porous safety film having a surface tension of between 33 dyn / cm and 38 dyn / cm. Such a characteristic proves to be sufficient in all possible variants for the thermoplastic resin and ink compositions of a protective device according to the invention. In particular, all the other characteristics of the support film can vary and be chosen and optimized according to the required properties. For example, the support film may consist of a simple paper coated on both sides with a layer of a high density polyethylene chosen so as to have a glass transition temperature high enough to withstand the lamination step at hot. The surface state of the support film can be adapted to the desired appearance, for example according to the matt or glossy appearance that it is desired to give the face of the visible safety film after lamination.

Moreover, advantageously and according to the invention, the protective device is rolled onto said surface portion of the official document:

at a lamination temperature of between 100 ° C. and 200 ° C., in particular between 100 ° C. and 120 ° C., and / or

with a pressure greater than or equal to 3.10 ⁵ Pa, which may be less than 10 ⁶ Pa-in particular under a pressure comprised between

4.10 ⁵ Pa and 6.10 ⁵ Pa-, and / or

during a period of between 1s and 10s, in particular between 4s and 6s.

The invention extends to an official document protected by a method according to the invention, with a device according to the invention. It therefore extends to an official document comprising at least one surface portion formed of a fibrous material protected by a transparent security film, characterized in that:

said security film comprises a single continuous layer determining the format of said security film and having a thickness of between 5 μπι and 25 μπι consisting of a thermoplastic resin having a glass transition temperature of between 30 ° C. and 120 ° C. especially between 35 ° C and 80 ° C-,

said security film is directly applied to said surface portion.

Advantageously and according to the invention, said surface portion is formed of a fibrous material selected from the group consisting of papers, non-thermoplastic synthetic papers, and synthetic papers. thermoplastics having a glass transition temperature greater than 70 ° C. The invention therefore extends in particular to a method for the safe protection of such a surface portion.

The invention also relates to a protection method, a protection device and an official document characterized in combination by all or some of the characteristics mentioned above or below.

Other objects, features and advantages of the invention will appear on reading the following non-limiting description which refers to the appended figures in which:

FIG. 1 is a diagrammatic cross-sectional view of a protection device according to one embodiment of the invention,

FIG. 2 is a diagrammatic cross-sectional view illustrating the protection device of FIG. 1 applied to a surface portion of an official document, before the lamination step,

FIG. 3 is a diagrammatic cross-sectional view illustrating the protection device of FIG. 1 applied to a surface portion of an official document, after the lamination step;

FIG. 4 is a diagrammatic cross-sectional view illustrating the protection device of FIG. 1 applied to a surface portion of an official document, after the step of lamination and removal of the support film;

FIG. 5 is a schematic perspective view of an exemplary protected official document according to the invention.

A device for protecting official documents according to the invention as shown in the figures comprises a support film 1 on one of its main outer faces, a security film formed of a single continuous layer 2 and, optionally, inscriptions or marks 3, 11.

This protective device constitutes a heat transfer, that is to say can be used to apply the security film 2, 3, 11 and transfer it by hot lamination on a surface portion 5 of an official document 9 , as shown in FIG. 5, in particular in order to protect it against falsification and / or to authenticate the official document and / or inscriptions variables or common previously printed on this portion of surface 5 and / or to ensure its integrity.

The continuous layer 2 of the security film determines the general format of the latter and is therefore chosen according to the format of the surface portion 5 to be protected. In the example of FIG. 5, the continuous layer 2 is of generally rectangular format to cover a portion of an identity card or a passport page. This single continuous layer 2 is formed of a thermoplastic resin having a glass transition temperature of between 30 ° C and 120 ° C printed in a flat of the corresponding format on the support film 1 with a thickness of between 5 μπι and 25 μπι. This impression can be made from a resin composition in a solvent medium by screen printing.

The thermoplastic resin constituting the continuous layer 2 can be chosen from the group consisting of vinyl thermoplastic resins, polyester thermoplastic resins and thermoplastic polyamide resins, and mixtures thereof. Advantageously, it is chosen from the group of vinyl thermoplastic resins, more particularly from the group formed by acrylic polymers and acrylic copolymers whose molecular weight is between 20,000 and 100,000 g / mol. For example, it may be chosen from acrylic resins marketed under the reference Neocryl®-B by the company DSM NeoResins + Waalwijk (The Netherlands). For its printing on the support film 1, this resin is mixed in a solvent medium chosen in particular according to the printing technique used.

The exact chemical nature of the thermoplastic resin of the continuous layer 2 is chosen as a function of the adhesion properties and the desired thermal properties, and according to the nature of the surface portion 5, of the type of official document 9 on which the the safety film and the lamination process used for the transfer are deposited.

For example: a high molecular weight vinyl type resin having a transition temperature advantageously between 35 ° C and 75 ° C, diluted in a screen printing solvent medium is suitable to achieve the continuous layer 2 by screen printing on a support film 1 consisting of a paper whose two faces are coated by coating with a high density polyethylene resin. The security film thus obtained can be transferred by lamination to about 100 ° C to 120 ° C for 5 seconds on an official document 9 such as an identity card, a driver's license or a passport with a portion of surface 5 paper or security paper. It should be noted that the lamination temperature corresponds to the temperature measured at the core of the continuous layer 2 during the lamination step, which corresponds to a substantially higher target temperature, for example of the order of 140 ° C. at 160 ° C.

For example, for screen printing, the solvent medium may for example comprise at least one solvent selected from light aromatic naphtha, ethyl 3-ethoxypropionate and trimethylbenzene.

The printing composition used to print this continuous layer 2 in a flat manner therefore comprises the solvent medium, the thermoplastic resin, optionally additives in a proportion of less than 10% by weight, especially anti-blocking, anti-ultraviolet and stabilizing additives. light.

The support film 1 must be rigid enough to be handled on the printing machines and has a face that can receive an impression, in particular by screen printing, of the continuous layer 2 and possibly safety markings 11. This face of the film support 1 must have a surface tension of between 33 dyn / cm and 38 dyn / cm for the one hand to allow this impression, on the other hand to act as a detachable support during a hot lamination operation. It is thus unnecessary to provide a layer of silicone or other detachment layer on the support film. In addition, this face of the support film 1 must be non-porous and non-absorbent so that the prints made on this face do not penetrate into the thickness of the support film 1 and can be transferred. For example, paper having at least one side coated with a high density polyethylene film can be used. It should be noted that the continuous layer 2 made with such thermoplastic vinyl resins is perfectly transparent in the visible range and short and long ultraviolet. Before printing the continuous layer 2 on the support film 1, it is possible to print patterns forming safety markings, for example with iridescent inks such as those sold under the reference OVTek® by the company TIFLEX Poncin (France) . Indeed, it is found that such inscriptions are then integral with the continuous layer 2 and transferred with the latter. Surprisingly, it turns out that the visual appearance and the quality of hanging of these inscriptions are excellent.

After printing of the continuous layer 2, it is also possible to print patterns forming security markings 3 which will then be interposed between the continuous layer 2 and the surface portion 5 of the official document, after the transfer of the security film. These security inscriptions 3 are for example made with photochromic inks or thermochromic inks or other. The ink composition used to make these safety markings 3 contains at least one pigment having the desired safety functions, a binder and a solvent medium. The binder used is of the same chemical nature as the thermoplastic resin of the continuous layer 2. For example, when the vinyl thermoplastic resin is formed of an acrylic copolymer, the binder used for the screen printing ink composition is the same acrylic copolymer.

This protective device thus obtained may be placed on a surface portion of an official document 9 as shown in FIG. 2. After the hot lamination at a temperature above 30 ° C. to 100 ° C. above the temperature of 30.degree. glass transition of the thermoplastic resin of the continuous layer 2, it is found that the inscriptions 3, 11 penetrate into the thickness of the continuous layer 2 as shown in FIG. 3, and that the support film 1 can be detached as shown in FIG. Security film thus transferred is very fine, and the security markings they wear are of excellent quality and perfectly protected. They are integrated in the thickness of the security film. It is not possible to modify them. Surprisingly, it is noted that this security film is of a quality superior to that of known security films such as films marketed under the reference Fasprotek® in accordance with EP-0271941 and US Pat. 5232527 or Passprotek® by Fasver. It can be applied under low pressure, especially less than 10 ⁶ Pa, is simple and inexpensive in manufacturing and installation, and can be used and / or manufactured with complex and tormented formats.

Examples:

A support film 1 is produced by coating a paper of 120 g / m ² on both sides with a high density polyethylene film reference Captive 600/105 from Loparex BV, Apeldoorn (The Netherlands).

A security inscription 11 is printed on one side of this support film 1 using an iridescent ink marketed under the reference OVTek® by TIFLEX Poncin (France). This printing is done in silkscreen mesh 120.31 son / cm.

A continuous layer 2 is then printed by serigraphic printing of a printing composition consisting of a vinyl thermoplastic resin and a screen printing solvent medium marketed under the reference CS090413 by the company TIFLEX Poncin (France). This impression is made in flat with a mesh 29.34 son / cm, so as to form a thickness of the order of 20 μιη.

Security inscriptions 3 are then printed on the continuous layer 2 after drying of the latter with a photochromic security screen printing ink sold under the reference 3Y1558 by TIFLEX Poncin (France).

In a first example, a vinyl thermoplastic resin consisting of a butyl methacrylate-methyl methacrylate copolymer with a molecular weight of 60,000 g / mol and a glass transition temperature (Tg) of 65 ° C. sold under the reference Neocryl B®-725 by the company DSM Waalwijk (Netherlands).

In another example, a vinyl thermoplastic resin consisting of a methyl methacrylate-ethyl acrylate copolymer with a molecular weight of 55,000 g / mol and a glass transition Tg of 43 ° C sold under the reference Neocryl B®-722 by the company DSM Waalwijk (Netherlands).

In another example, a vinyl thermoplastic resin consisting of a copolymer of ethyl acrylate-butyl methacrylate with a molecular weight of 40,000 g / mol and a Tg of 74 ° C. marketed under the reference Neocryl B®-735 was used. by the company DSM Waalwijk (Netherlands).

In another example, a vinyl thermoplastic resin consisting of a butyl methacrylate-methyl methacrylate copolymer with a molecular weight of 55,000 g / mol and a Tg of 59 ° C. marketed under the reference Neocryl B®-810 was used. DSM Waalwijk (Netherlands).

In another example, a vinyl thermoplastic resin consisting of an ethyl acrylate-ethyl methacrylate-methyl methacrylate copolymer with a molecular weight of 45,000 g / mol and a Tg of 52 ° C. marketed under the reference was used. Neocryl B®-814 by the company DSM Waalwijk (Netherlands).

In another example, a vinyl thermoplastic resin consisting of a butyl-styrene methacrylate copolymer with a molecular weight of 40,000 g / mol and a Tg of 49 ° C. sold under the reference Neocryl B®-819 by the company was used. DSM Waalwijk (Netherlands).

In another example, a vinyl thermoplastic resin consisting of a butyl methacrylate-methyl methacrylate copolymer with a molecular weight of 45,000 g / mol and a glass transition temperature (Tg) of 40 ° C. sold under the reference Neocryl B®-859 by the company DSM Waalwijk (Netherlands)

In each example, the security film obtained as indicated above on the support film 1 is transferred to a hot-lamination passport page at a higher lamination temperature of 30 ° C to 100 ° C above the temperature. glass transition of the thermoplastic resin of the continuous layer 2, without exceeding the glass transition temperature of the high-density polyethylene constituting the support film 1.

As can be seen diagrammatically in FIG. 5, the safety film whose thickness is of the order of 20 μπι perfectly adheres to the passport, does not in any way interfere with the visualization of the variable or common inscriptions 4 carried by the passport page. , and that the safety markings 3, 11 are of excellent quality and extremely resistant.

In particular, with the security film of the last example mentioned above (Neocryl B®-859 resin), rolled to a target temperature 160 ° C +/- 5 ° C on a driving license paper for 5 seconds under about 5.10 ⁵ Pa we obtain the following results:

thickness measured according to ASTM standard D374-99: 20 μπι +/- 5 μπι,

- breaking strength measured according to ASTM D882-02 at a speed of 300 mm / min: 3 N / mm ² +/- 1.5 N / mm ² ,

- measured transparency according to ASTM D1003-00:> 90%,

- adherence measured according to ISO 8510-2 at a speed of 300 mm / min and an angle of 180 °: the minimum value is that of the deterioration of the peak paper test,

- Ultraviolet A resistance measured according to ISO 4582 and DIN 6167: samples are placed 75h at 60 ° C and 0.72 W / m ² / nm, then the yellowness difference ("G" from 0 to 100) and the difference in transparency between before and after test: maximum gap G = 5, transparency = 3, no degradation,

- abrasion measured according to the ICAO standard: no degradation observed after 5000 round-trip passages with a roller of 15 mm diameter weighted with 500 g, - climatic aging measured according to standards NF T 76-109 and DIN 6167: seven cycles D4 then the yellowness difference ("G" from 0 to 100) and the difference in transparency between before and after test: maximum deviation G = 6, transparency = 3, no degradation.

In another example, with a resin layer 2 of μπι +/- 5 μπι, even a measured breaking strength of 2 N / mm ² is obtained. These properties are unexpected and similar to those obtained with a security film conforming to EP-0271941 and US-5232527 having a thickness of 20 μπι +/- 5 μπι, but whose tensile strength measured under the same conditions is equal to 20 N / mm ² +/- 5 N / mm ² .

Comparative tests have been carried out between multilayered safety film protectors designated A, B, C, and D according to the state of the art, and protective devices with a designated single-layer security film. E and F according to the invention on the properties:

- adhesion

- resistance to use

- resistance to forgery

Table 1 below gives the characteristics of the security films used.

Table 1

Protective Varnish Adhesive Impressions

security

A Polyurethane Acrylic Adhesive Intercalated between the

polymerized based heat-sealable protective varnish and hydroxylated polyester the adhesive layer and a

polyisocyanate

B Acrylic drying Adhesive acrylic Intercalated between the

UV heat-sealable protective varnish and adhesive layer

C Acrylic Drying Acrylic Adhesive Intercalated Between

UV heat-sealable protective varnish and adhesive layer

D Acrylic Drying Resin Neocryl B® - Intercalated Between

UV 859 protective varnish and adhesive layer

E Neocryl B® Monolayer Resin - 859 Placed on the outside of the security film

F Neocryl B® single-layer resin - 859 Interposed between the safety film and the support The security films are hot-rolled on a fibrous material substrate at the following lamination conditions: 170 ° C. +/- 5 ° C., under 3.10 ⁵ Pa, with a speed of 5 revolutions / min.

TEST OF ADHERENCE

An adhesive tape is placed on the laminated safety film on the fibrous material substrate and a peel test is carried out according to ISO 8510-2. Table 2 below gives the results obtained.

Table 2

(1): adhesion greater than 6N / 25 mm greater than the cohesion of the fibrous material. The film peels off by defibrating the top of the paper.

RESISTANCE TO USE

Abrasion tests are carried out on the rolled films on the substrate of fibrous material according to the ICAO standard, 10,000 round-trip passages with a roller of 15 mm diameter weighted with 500 g. Table 3 below gives the results obtained.

Table 3

Result

No degradation

B No degradation

C No degradation

D No degradation

E No degradation

F No degradation RESISTANCE TO FALSIFICATION

An attempt is made to remove the security film from the fibrous material substrate on which it has been laminated, so as to recover it as intact as possible (no degradation of the film or visible security prints). This is to evaluate its ability to be reused by gluing or lamination on the medium whose variable information has been falsified or on another support corresponding to a false. Table 4 below gives the results obtained.

Table 4

(1): A "label-removed" solvent and a reinforcement are used.

(2): Different methods were used - various solvents tested, thermal activation and reinforcement to stabilize the film.

These tests demonstrate that, completely unexpectedly, a security film (E, F) according to the invention has adhesion, abrasion and wear resistance and abrasion resistance properties which are as good or even better than those of the multilayer films (A to D) among the most efficient of the state of the art.

Claims

1 / - A method of safely protecting a surface portion (5) of an official document (9) made of a fibrous material, wherein:

a device is chosen for protecting by hot transfer of a transparent security film extending in a format adapted to that of said surface portion (5) and carried by a support film (1) adapted to allow the transfer to hot said security film on said surface portion by lamination of the protective device on said surface portion,

said heat film is hot-transferred onto said surface portion (5), characterized in that:

a protection device is chosen whose said security film comprises a single continuous layer (2) determining said format and having a thickness of between 5 μπι and 25 μπι consisting of a thermoplastic resin having a glass transition temperature of between 30 ° C. C and 120 ° C,

said protective device is rolled onto said surface portion (5) by applying said security film directly to said surface portion at a lamination temperature higher than said glass transition temperature so as to transfer said security film to said said surface portion.

21 - Process according to claim 1, characterized in that said laminating device is laminated at a higher lamination temperature of 30 ° C to 100 ° C to the glass transition temperature of said thermoplastic resin.

3 / - Method according to one of claims 1 or 2, characterized in that a protective device is chosen which said single continuous layer (2) of the security film consists of a thermoplastic resin whose molecular weight is understood between 20,000 g / mol and 100,000 g / mol.

4 / - Method according to one of claims 1 to 3, characterized in that a protective device is chosen which said single continuous layer (2) of the security film is made of a thermoplastic resin vinyl selected from the group consisting of acrylic polymers and acrylic copolymers.

5 / - Method according to one of claims 1 to 4, characterized in that a protective device is chosen which said single continuous layer (2) of the security film consists of a vinyl thermoplastic resin selected from the group formed polymeric materials: methyl methacrylate-ethyl acrylate, butyl methacrylate-methyl methacrylate, ethyl acrylate-ethyl methacrylate-methyl methacrylate, butyl-styrene methacrylate, methyl methacrylate, and butyl methacrylate.

6 / - Method according to one of claims 1 to 5, characterized in that one chooses a protective device whose security film comprises at least one inscription (3, 11) printed on at least one of its faces using an ink composition.

II - Method according to one of claims 1 to 6, characterized in that a protective device is chosen comprising a support film (1) having a non-porous security film receiving face having a surface tension of between dyn / cm and 38 dyn / cm.

8 / - Method according to one of claims 1 to 7, characterized in that said protective device is rolled over said surface portion (5) of the official document:

at a lamination temperature of between 100 ° C. and 200 ° C., and / or

with a pressure greater than or equal to 3.10 ⁵ Pa, and / or

- for a period of between 1s and 10s.

91 - Device for the safe protection by hot transfer on a surface portion (5) of an official document (9) made of a fibrous material, comprising:

a transparent security film extending in a format adapted to that of said surface portion (5), a support film (1) carrying said security film and adapted to allow hot transfer of said security film to said surface portion by lamination of the protective device on said surface portion, characterized in that:

said security film comprises a single continuous layer (2) determining said format and having a thickness of between 5 μπι and 25 μπι consisting of a thermoplastic resin having a glass transition temperature of between 30 ° C and 120 ° C,

said security film is directly applied to said surface portion (5).

10 / - Device according to claim 9, characterized in that said single continuous layer (2) of said security film consists of a thermoplastic resin whose molecular weight is between 20,000 g / mol and 100,000 g / mol.

11 / - Device according to one of claims 9 or 10, characterized in that said single continuous layer (2) of said security film consists of a vinyl thermoplastic resin selected from the group consisting of acrylic polymers and acrylic copolymers.

12 / - Device according to one of claims 9 to 11, characterized in that said single continuous layer (2) of said security film consists of a vinyl thermoplastic resin selected from the group consisting of the following polymeric materials: methyl methacrylate ethyl acrylate, butyl methacrylate-methyl methacrylate, ethyl acrylate-ethyl methacrylate-methyl methacrylate, butyl-styrene methacrylate, methyl methacrylate and butyl methacrylate.

13 / - Device according to one of claims 9 to 12, characterized in that said security film comprises at least one inscription (3, 11) printed on at least one of its faces with a composition ink.

14 / - Device according to one of claims 9 to 13, characterized in that said support film (1) has a receiving face of the film of non-porous safety having a surface tension of between 33 dyn / cm and 38 dyn / cm.

15 / - Official document comprising at least one surface portion (5) formed of a fibrous material protected by a transparent security film, characterized in that:

said security film comprises a single continuous layer (2) determining the format of said security film and having a thickness of between 5 μπι and 25 μπι consisting of a thermoplastic resin having a glass transition temperature of between 30 ° C. and 120 ° C. ° C,

said security film is directly applied to said surface portion (5).

16 / - Document according to claim 15, characterized in that said surface portion (5) is formed of a fibrous material selected from the group consisting of papers, non-thermoplastic synthetic papers, and thermoplastic synthetic papers having a transition temperature glassy upper than 100 ° C.