FR2467089A1 - Forge proof documents - coated with liq. UV curable epoxy! acrylate! varnish contg. monomolecular layer of luminescent pigment, covered with heat sealed film - Google Patents

Abstract

Anti-forgery coating for security articles is made by first grinding a crystalline rare earth luminiferous substance to a particle size of 25-50 microns, and uniformly dispersing 8-15wt.% of the prod. into a UV-curable liq. binder comprising an epoxy acrylate resin and a photoinitiator. One or both faces of the article is then coated with the varnish such that the whole of the information carried on the article is coated, the thickness of the coating being adjusted such that the luminiferous crystals form a monomolecular layer. A transparent protective film is then applied over the article whilst the varnish is still wet and the whole is calendered to even out the coating, to remove excess varnish, and to preserve the monomolecular distribution of the luminiferous pigment. The protective films are then sealed to the edges of the article by high frequency welding and the whole is exposed to UV to cure the varnish. Process allows prodn. of forge-proof documents, identity cards, etc., using prodn. line techniques.

Description

 The present invention relates to a method for the anti-falsification protection of information carried on various media such as documents, securities, titles, identification cards or the like, from a computer.

 The invention also relates to an installation for the industrial application of this process, in particular a continuous production line.

 Before approaching the main provisions of the invention, it is necessary to recall, on the one hand, the known means with a view to giving information media anti-falsification protection and, on the other hand, to recall the difficulties encountered in the occasion of the application of such processes at the industrial stage, in the absence of exploitable education.

 The method according to the present invention proposes to use, among other components, for the anti-forgery protection of information carriers, compositions comprising so-called photoluminescent substances, also called photophores.

 Among these substances, we will mention those based on rare earth metals, endowed with the power to emit when they are excited by a radiation at relatively long wavelength, preferably infrared, a radiation at shorter wavelength , especially visible light.

 The properties of these compositions have been highlighted by the researcher François AUZEL, in several communications to the Academy of Sciences, since 1966, in the description of the phenomenon called "antistockes".

 The application of the antistock properties of substances based on rare earth metals has been described in the French patent AUZEL No. 1,532,609 applied for on June 1, 1967.

 This patent describes in particular various methods for preparing compositions, as well as screens prepared from these compositions, to serve for the detection of radiation from the so-called near infrared band. The AUZEL patent also describes an apparatus for detecting the presence in a screen of said compositions.

The application of photophores in the anti-forgery function of documents, was described in a patent application in
Austria, deposited on May 3, 1972 under No. A.3827 / 72 in the name of International
Security Systems SA

 In this application, substances which are not commercially available are recommended, chosen from fluorescent materials according to concentrations determined on the whole or in one or more places of the paper for titles or values, materials which, being excited, are fluorescent and exhibit characteristic emission spectra in the visible range. Since many of these substances are colorless, they cannot be seen with the naked eye.

 However, the Austrian patent application does not give a concrete example on the nature of otherwise known fluorescent substances, nor on their preparation process, nor on the process of incorporation into an information carrier. there is therefore, therefore, no practical teaching for the implementation of the anti-falsification process claimed in order to produce an industrial product.

 On the other hand, in this application, an apparatus for controlling the presence of fluorescent substances is also described.

We also know, by another Austrian patent, filed on July 26, 1974, the application of phosphors to valuable paper or similar document, this application consisting in covering the paper with a layer of
homogeneous protection, either before or after the printing of the information carried by the document, the luminance properties, or spectral reflection,
or fluorescence of the paper, the protective layer and the printing ink of the information, being such that the deteriorations of the protective layer can be detected, either in the wavelength of light used for the information reading, either under a particular control wavelength.

 Thus, if it is desired that the document be checked during the reading operation, the Austrian patent proposes to use, among other solutions, a light source which, despite a good contrast between the background printing and the printing of 'information, at the same time excites the fluorescence of the additives contained in the paper.

 In the second Austrian patent, neither the nature of the known fluorescent substances is given, nor the process for applying them for the production of an information medium.

Finally, the French patent application will be cited for the record.
AB ID-KORT, of October 24, 1975-, which claims a process for marking documents using a substance based on rare earth metals, having the antistocking property demonstrated and described in the prior patent
AUZEL from 1967.

 It will be noted that the AB ID-KORT patent mentioned above gives no indication of the process for the preparation of the claimed substance, and that there is no teaching there on the process and on the means of manufacturing it. an anti-falsification information medium.

 The main object of the present invention is therefore a method of preparing an anti-forgery information medium, in the context of industrial manufacturing.

 Another object of the invention is to provide an installation for the industrial application of the present process.

 Another object of the invention is to ensure effective protection of the information of a medium by making detectable attempts to falsify.

 To achieve these goals, the invention relates first of all to a method for the preparation of an anti-falsification information medium, using, for the verification of authenticity, at least one substance based on metals. of rare earths, preferably with antistocking property per se known, reduced to the state of crystalline powder and which is incorporated into a varnish intended to constitute the anti-falsification protective layer of the information medium P this process is characterized in that it consists, on the one hand, - in reducing the phosphor crystals to a particle size between 20 and 50 / * on the other hand, - in constituting the varnish from acrylic epoxy resins, with a high power of adhesion, and to introduce into the selected resin photos initiators giving the varnish a reactive power by crosslinking under ultraviolet exposure, on the other hand, - to be dispersed in the varnish, being in the form of a liquid reagent with low density , 8 to 15% of phosphor crystals, and to keep the mixture under constant stirring to keep the crystals in the dispersed state until the coating operation of the information medium, on the other hand, then - to coat the sides of the information carrier, so as to completely cover the information-carrying surface, and to adjust the thickness of the film so as to obtain a mono-molecular arrangement of the phosphor crystals, then to double-coat the coating varnish , using a transparent mechanical protection film, while the varnish is still in the liquid state, on the other hand, - subjecting the complex information carrier, varnish, and mechanical protection film, to a calendaring action to keep the regular dispersion of the phosphor crystals in the varnish, let the excess varnish flow, and equalize the thickness of the varnish to the dimension of the phosphor crystals, on the other hand, finally - to combine the mechanical protection films u varnish by high-frequency welding, following the contours of the information medium, then subjecting the protective varnish of the information medium to exposure under ultraviolet rays, so as to transform the varnish in the liquid state into solid, flexible, tamper-resistant film, at least in relation to the protected face of the information carrier.

 It is understood that by the main provisions of the present process, it becomes easy to industrialize each step and to lead the manufacture of an information medium in which priority has been given to the protection of information, which can no longer be reached by the counterEditor, without going through a joint destruction of the varnish including the luminolhores and the information medium.

According to a provision of the present process, the phosphor crystals are reduced to a particle size of 24 μ, in that for an application of the protective varnish to a support based on cellulose, paper or cardboard, the varnish is constituted by a composition comprising approximately 10%
phosphor crystals, a trimethylol propane, a triacrylate, in the presence
a photo initiator, in particular a dibenzoy-dimethyl acetal, entering the
composition in a proportion between I and 5%.

According to another provision of this process, for the
continuous manufacturing of information, it consists
- to constitute the information support in the form of a continuous band on
which we transfer the information from each medium,
- to provide this strip of Carol perforations to make it progress
through various manufacturing stations,
- to precut the outline of each information medium,
- coating the surfaces of the information carrier with protective varnish,
- to cut out the material bridges that hold the information medium to the
perforated strip,
and
- to transfer, preferably on an air cushion, the coated support and introduce it
between mechanical protection films,
- to schedule the varnish under protective films, then to weld these films around the
outline of the information carrier, and to follow this welding with a phase of
crosslinking of the varnish,
- to separate the information medium from the mechanical protection films, by
cut in the contour of the weld strip.

The invention also relates to an installation for
continuous manufacturing of an anti-falsification information medium,
in the form of a continuous chain comprising, among other stations - a punching table for the production of Carol perforations on the banks
of the constituent strip of the information carriers, at least one step-by-step feed device engaged with the perforations of
said strip, a first precut press for the production of information media
individual mations retained at the banks of the strip by bridges of material not
- a coating group supplied with varnish under constant agitation and comprising
a set of transfer cylinders with device for adjusting the thickness of the
layer of transferred varnish, - a separating device for cutting the attachment points between each information carrier and the initial continuous strip, and thereafter, a device for transferring the coated information carrier, preferably on an air cushion , to introduce each support between the supply and pressure cylinders of the mechanical protection film which forms a new continuous strip, - a high frequency welding device, followed by a crosslinking tunnel with ultraviolet lamps and, subsequently, - a second cutting press for once again separating the information medium trapped in the mechanical protection film with respect to the continuous strip of this film.

 The invention also relates to an anti-falsification information carrier consisting of a support core, for example paper, carrying information, the faces of this support core being coated with anti-defoliation adhesion varnishes, containing crystals. phosphors arranged in a mono-molecular layer in such a way that these crystals are distributed homogeneously on the faces of the support core and on the information carried on this support, without altering the visual reading of this information, this support core preferably being but not necessarily coated on both sides with a transparent PVC / polyester mechanical protection complex trapping the information medium.

Other characteristics and advantages of the invention will emerge from the following detailed description of an embodiment of a manufacturing chair for the implementation of the present method, given here by way of example and illustrated on the attached drawings in which
Figure 1 is a schematic sectional elevation view of a production line.

 Figure 2 is a schematic view showing on a very large scale the detail of the shaper of the production line.

 Figure 3 is a view of an information carrier showing in a partial enlargement the distribution of the photoluminescent particles in the protective varnish.

 With reference to the accompanying drawings, in particular FIGS. 1 and 2, the process for the preparation of an information medium will be explained jointly, using an example of complete industrialization, on a production line, designated by the general reference 10.

 In the example chosen, the method is more particularly applied to the production of an information medium 11, such as paper or cardboard, in the form of a continuous strip which is perforated along its edges , according to the terforation process Carol, using a perforating device 12, known per se, which allows it to advance this strip, step by step, through the various stations of the production line.

 This step-by-step advance will be provided in particular by toothed wheels 13a, 13b, engaged with the Carol perforations.

 The continuous strip 11 is first subjected to a precut on a first press 14, the cutting tool 15 of this press being designed to precut in the strip 11, the outline of each information medium, in order to obtain individual information carriers, retained at the edges of the strip by bridges of uncut material.

 We then proceed to the double-sided coating of the information medium, using a varnish 16, applied by means of a coating assembly 17, of helio type, making it possible to deliver a constant thickness of varnish, on the sides of the information carrier.

 In the embodiment chosen, the protective varnish is made up of a composition comprising a trimethylol propane, a triacrylate, in the presence of a photo initiator, in particular a acetal dibenzoydimethyl, entering into the composition in a proportion of between 1 and 5%.

 In this composition, phosphor crystals 18 (Figures 2 and 3) were introduced, the particle size of which was reduced, preferably to 24 / v. The phosphor is introduced into the varnish in a proportion close to or equal to 10%. One or more agitators 19 are provided in the varnish tanks of the coating group 17, to keep the particles of phosphors in suspension in the varnish.

 At the outlet of the coating device, the information carrier is separated from the continuous strip 11, by means of knives 20, which cut the bridges of material, between the information carrier and the strip. The paper strip 11 is deflected from the axis of progression of the information carriers, by means of a pipe roller 21, a toothed capstan 22, and a weeding roller 23. The progression of the carrier coated information, is preferably provided by an air cushion transfer device 24, in the direction of a calibrating device 25, which layer on the coating of the information carrier, a transparent protective film, respectively 26a, 26b , - cut from delivery rollers 27a, 27b.

 The transparent protective film is made up of a two-component complex, a polyester film 26 ′, and a polyvinylchloride film 26 ", the latter being, for its compatibility with the adhesive power of the varnish, applied in contact with the latter. Reference will be made more particularly to FIG. 2, which shows the detail of the calendaring phase, by means of the pressing rollers 25a, 25b. The purpose of the calendaring operation is to make the excess varnish flow. adhesion 16, in which the phosphor particles or crystals 18 are coated, so that the thickness of the layer of varnish does not exceed the average thickness E of the phosphor crystals. It goes without saying that the thickness of the information signs 28 of the support 29, has no influence on the regularity of the average thickness of the calendar varnish layer.

 Thanks to the control of the thickness of the coating layer, followed by the calendering phase, the formation of a monolecular layer of phosphor crystals is obtained, in particular by the pressure effect of calendering. - say a layer in which the crystals are neither juxtaposed nor superimposed.

 This mode of distribution of the phosphor crystals in the information protection layer is particularly desired, on the one hand to allow a perfect definition of the outline of the signs of information carried on the support 20, on the other hand, to detect , in the event of an attempt at falsification, changes in the distribution and number of the phosphor crystals.

 The complex coated with the anti-falsification varnish and the mechanical protection complex is introduced, while the varnish is still in the unpolymerized state, in a high frequency welding station 30, which binds the mechanical protection films 26a, 26b , by a continuous weld 31, which follows the contour of the information carrier.

When the complex is assembled and welded, it is introduced
dtns a crosslinking station 31, inside which operates the phase of adhesivation and crosslinking of the protective varnish 16. This crosslinking is obtained in particular by exposure to radiation from ultraviolet lamps 32a, 32b, the time of which d exposure is regulated by shutter drawers 33, controlled by electromagnets and time relays not shown.

 After crosslinking, each information carrier is again subjected to cutting through a second press 33, which cuts the information carrier around the contour of the weld strip 31.

Leaving the press 33, the continuous strip, cut, formed from the union of the films 27a and 27b, is led out of the production line of the installation, in the direction of a weeding cylinder 34. It goes from As a result, contrary to what is shown in FIG. 3, the phosphor crystals are not perceptible on the surface of the information carrier. To detect their presence or their lack of presence, the information carrier is subjected to exciting radiation belonging to the so-called near infrared band, which makes the radiation emitted by the phosphor crystals visible.

 Of course, the invention is not limited to the exemplary embodiments described and shown above, for which other variants can be provided, without thereby departing from the scope of the appended claims.

Claims (1)

CLAIMS I) Process for the preparation of an anti-falsification information medium, using, for the verification of authenticity, at least one substance based on rare earth metals, preferably with antistock properties per se known, reduced to the state of crystalline powder, and which is incorporated into a varnish intended to constitute the anti-falsification protective layer of the information medium, a process characterized in that it consists, on the one hand, in reduce the phosphor crystals to a particle size between  25 and 50 / u- on the other hand, - to constitute the varnish from high power acrylic epoxy resins  adhesion, and to introduce initiator photos into the selected resin  giving the varnish a reactive power by crosslinking under ultraviolet exposure, on the other hand, - to be dispersed in the varnish, being in the form of a liquid reagent to  low density, 8 to 15% of phosphor crystals, and to maintain the mixture  under constant stirring to maintain the crystals in the dispersed state until  the operation of coating the information carrier, on the other hand thereafter, - coating the face (s) of the information carrier, so as to coat  the information-carrying surface, and to adjust the thickness of the  film so as to obtain a monolecular arrangement of the crystals  phosphors, then double-coat the coating varnish with a  transparent film, while the varnish is still in the liquid state, on the other hand, - subjecting the complex information carrier, varnish, and mechanical protection film, to a calendaring action to keep the regular dispersion of phosphor crystals in the varnish, let the excess varnish flow and equalize the thickness of the varnish to the dimension of the phosphor crystals, on the other hand finally, - to join the mechanical protection films of the varnish by a high weld  frequency, following the contours of the information medium, then to submit  the protective varnish of the information medium at an exposure under rays  ultraviolet, so as to transform the varnish in the liquid state into a film  solid, flexible, unbreakable, at least in relation to the protected face of the  information carrier.  2) Method according to claim 1, characterized in that the phosphor crystals are reduced to a particle size of 27, L, in that for an application of the protective varnish to a support based on cellulose, paper or cardboard, the varnish is made up of a composition comprising approximately 10% of phosphor crystals, a trimethylol propane, a triacrylate, in the presence of a photo initiator, in particular a dibenzoydimethyl acetal entering the composition in a proportion of between 1 and 5%.  3) Method according to any one of claims 1 and 2, characterized in that for the coating phase of the transparent mechanical protection film on the varnish, this film is formed by a two-component complex, a polyvinyl chloride film associated with a polyester film, the PVC film being, for its compatibility with the adhesive power of the varnish, applied in contact with the latter.  4) A method for the continuous manufacture of an information medium according to any one of claims 1 to 3, characterized in that it consists - of constituting the information medium in the form of a continuous strip on  which we transfer the information from each support, - to provide this Carol perforation strip to make it progress in  step by step advance indexed through various manufacturing stations, - to precut the outline of each information carrier, - to coat the faces of the information carrier with protective varnish, - to cut the bridges of material that hold the support of information  to the perforated strip, and, to be transferred, preferably on an air cushion, the coated support and introduce it  between the mechanical protection films, to schedule the varnish under protective films and then to weld these films around  of the outline of the information carrier, and to follow this welding with a  crosslinking phase of the varnish, to separate the information carrier from the mechanical protection films, by  cut in the contour of the weld strip.  5) Installation for the continuous manufacture of an anti-falsification information medium obtained according to any one of claims 1 to 4, characterized in that it is in the form of a continuous chain comprising, among other stations - a punching table for the production of Carol perforations on the banks  of the constituent strip of the information carriers, - at least one step-by-step advance device engaged with the perforations of  said strip, - a first precut press for the production of supports  of individual information retained at the banks of the strip by bridges of  uncut material, - a coating group supplied with varnish under constant agitation and  comprising a set of transfer cylinders with device for adjusting  the thickness of the layer of transferred varnish, - a separating device to cut the bridges of attachment between each support  information and the initial tape continues, and as a result, a device  transfer of the coated information medium, preferably on an air cushion,  to introduce each support between the delivery and pressure cylinders of the  mechanical protection film, which forms a new continuous strip, - a high frequency welding device, followed by a polymerization tunnel  with ultraviolet lamps and, subsequently, a second cutting press for  again separate the information medium trapped in the film from  mechanical protection, compared to the continuous strip of this film.  6) anti-falsification information carrier obtained by the method and the installation according to any one of claims I to 5, characterized in that it consists of a support core, for example paper, carrying information, the faces of this support core being coated with anti-defoliation adhesion varnish containing phosphor crystals, arranged in a mono-molecular layer so that these crystals are distributed homogeneously on the faces of the support core, and on the information carried on this support, without altering the visual reading of this information, this support core being preferably, but not necessarily, coated on both sides with a transparent complex of PVC / polyester mechanical protection, trapping the information support.