CA1336053C

CA1336053C - Self adhesive tamper-proof information medium and its application to the non-falsification of documents

Info

Publication number: CA1336053C
Application number: CA000601011A
Authority: CA
Inventors: Michel Camus; Jean-Paul Menez
Original assignee: ArjoWiggins SAS
Current assignee: ArjoWiggins SAS
Priority date: 1988-05-31
Filing date: 1989-05-29
Publication date: 1995-06-27
Anticipated expiration: 2012-06-27
Also published as: EP0345130B1; AU3516989A; FR2631990B1; FI892622A; ATE82765T1; AU619839B2; DE68903600D1; EP0345130A1; FI892622A0; FR2631990A1; DE68903600T2; ES2036815T3

Abstract

The invention concerns a self-adhesive tamper-proof medium intended to be placed over a substrate.
It is formed of at least a planar printable structure overlaid with an adhesive layer, the planar structure and the adhesive being such that the adhesive layer is partially absorbed in the thickness of the planar structure. Preferably, the planar structure is a sheet of natural and/or synthetic fibres whose sizing degree is 5.
Applications in particular include means to prevent the falsification of passports.

Description

SE U ADHESIVE TAHPER-PROOF INFORHATION HEDIU~ AND ITS APPLICATION
TO lHE NON-FALSIFICATION OF DOCUMENTS
The invention concel-ns a self-adhesive tamper-proof information medium,and more particularly pressure adhesive paper, 05 espec;ally of the type intended to receive a stamp and/or inscription eg. a visa.
Transparent self-adhesive films are already known and used to protect information media such as photogl-aphs, signatures written on passports or identity cards. Such films are described in the following documents : GB-A-2 128 581, GB-A-615 666, GB-A-2 013 571 and GB-A-1 589 395. These films are transparent and made from sheets of plastic material. Their essential purpose is to protect information whilst leaving it visible. They contain print which is invisible to natural light and which is covered by a pressure- sensitive adhesive layer. As an example, the print has a greater affinity to the adhesive than to the plastic film. Therefore, when the film is adhered over an area of information and a counterfeiter attempts to remove the film to modify the information, there occurs a delamination of both the adhesive and the film, while the print remains on the information medium and the latter thus becomes unus~ble by the counterfeiter.
These plastic films known from prior art allow the protection of information media such as photographs or signatures written, for example, on a passpol~ or any other official document and prevent the counterfeiter from removing these photoy~aphs to replace them by others and/or altering the filled in parts (name, age, signature).
US Patent number 3 623 944 ~;~closes a self-adhesive friable polymer film for the protection of a subs~-a~e. The film and the adhesive must be chosen so that the tear resistance of the film is less than the adhesive force between the adhesive and the subs~l-aLe. Attempts to falsify the subs~La~e are evidenced by the partial (or total) destruction of the friable film in tearing it away. However, this security system has a number of drawbacks :

2 13~6053 - very specific compositions are required for both the polymer film and the adhesive, - they are produced in a solvent medium, which means that in addition to the well-known problems connected with the use of 05 solvents (cost, toxicity, explosion hasards) the self adhesive film itself can only be very partially tamper proof.
Indeed such a film cannot incorporate some anti-tampering agents used for safety documents, in particular those that react to solvents. This self adhesive film can therefore be counterfeited.
Moreover, it can be unstuck by dissolving the adhesive using the solvent employed for its preparation.
The present invention has a totally different aim. One aim of the invention is to provide a tamper-proof info~ Lion medium that cannot be counterfeited.
A second aim of the invention is to provide an information medium which when printed and/or written on and when placed on an organic substrate such as the page of a passport or identity card, cannot be removed by counterfeiters.
Another aim of the invention is to provide an information medium intended to receive print and/or writing, said print and/or writing being infalsifiable.
Another aim of the invention is to make locally tamper-proof a document that was not initially intended to be so.
Indeed, passports are very often marked, usually by means of stamps, with visas, marks and other signs. Up until now, counterfeiters could very easily modify the mark or writing appended to such a substrate. They could just as easily print over the subsLlaLe by making false stamps.
It is therefore an aim of the presenL invention to provide a means for preventing the falsification of visas marked over substrates, especially passport pages or identity cards.
The invention concelns a self adhesive tamper-proof information medium intended to be placed on an organic subsL~-aLe and to receive print and/or writing. This information medium has a planar structure, is flexible, tamper-proof, printable, and

3 1336053 covered with a pressure-sensitive adhesive layer; the adhesive layer and planar structure are such that the self-adhesive tamper-proof medium cannot be taken apart from the substrate without at least partially destroying the substrate and possibly the planar structure. Thus, when the information medium is placed on a substrate, the mechanical removal of the medium causes the substrate to be delaminated and/or the planar structure to be torn.
Another aspect of this invention is as follows:
Self-adhesive tamper-proof medium intended to be placed on an organic substrate, wherein it is formed of at least one printable, tamper-proof planar structure covered with a pressure-sensitive adhesive layer, which is partially absorbed in the thickness of the planar structure, the planar structure and the adhesive being such that the self-adhesive tamper-proof medium cannot be removed from the substrate without at least partial destruction of the substrate.
According to one embodiment of the invention, the planar structure is a partially or totally fibrous structure eg. a sheet formed by natural and/or synthetic fibres, and is preferably a sheet of paper obtained by a wet process. The plane structure can be a composite and can consist of at least one fibrous sheet in association with at least one continuous sheet, eg. a plastic sheet. This plane structure can for example be formed of a plastic sheet overlaid, at least on one face, by a layer composed of bonding agents and pigments.
According to a specific embodiment of the invention, the adhesive layer is partially absorbed in the thickness of the plane structure.
According to another embodiment of the invention, the plane structure is a sheet of natural and/or synthetic fibres the sizing degree of which is equal to 5.

r~

3a According to another embodiment of the invention, the structure is a sheet of tamper-proof paper that includes a security means chosen among security threads and fibres, interrupted patterns and watermarks.
According to another embodiment of the invention, the plane structure is a paper that takes on a different colour to its original colour when submitted to an alkali, acid, an oxydoreduction couple, water, sodium hypochlorite, or solvents.
According to an alternative embodiment of the invention, the plane structure contains a coloured layer that reacts to the action of an alkali, acid or to water.
According to another alternative embodiment of the invention, the adhesive is such as to adhere the plane structure to

4 1336053 $he substrate in a time period of a few minutes to five hours.
According to another alternative embodiments of the invention, the adhesive is overlaid with an anti-adhesion sheet.
Preferably, the adhesive layer is absorbed within û5 approximately one third of the thickness of the plane structure.
It is indeed a requirement according to the invention that the adhesive layer only superficially - and not totally penetrates into the plane fibrous structure. A penetration of the adhesive throughout the entire plane structure would bring in too great an adhesion of the latter. When the information medium is printed and subsequently placed over a substrate, one aim of the invention is that the information medium cannot be disassociated from the substrate; and when a counterfeiter attempts to mechanically remove the information medium, the structure becomes delaminated owing to the weak cohesion of the fibrous structure.
The information medium can for example be a highly sized paper, the size preventing the adhesive deposited on the information medium from being totally absorbed into the thickness of the latter. The degree of sizing can be equal to sizing degree n5 according to the French AFNOR Q03-015 standard appended here for reference, which is similar to the American TAPPI
standard "size test for paper by ink resistance" which is also appended here for reference.
The AFNûR Qû3-û15 standard consists in tracing lines on paper using coloured solutions of increasing degrees of aggressiveness.
The most aggressive of these solutions which allows lines to be drawn without smearing or transudation are taken to characterise the sizing degree of the paper under test. The compositions of the solutions to use are laid out in the following table :

Composition of solutions Coloured solution Ns in order of increasing CI 74 180 CI 42 045 aggressiveness in grams per litre 2 7.5 2.5 4 2.5 7.5 The following dye solutions are used as the reactants :
direct dye : CI 74 180 colour index (weakly aggressive dye). This dye can be sold for example by ICI Francolor under the name "Turquoise diazol lumière JLS".
Acidic dye : CI 42 045 colour index (highly aggressive dye). This dye can be sold for example by ICI Francolor under the name "Bleu sulfacide brillant 6Jn.
Solutions numbered 1 to 5 for each of the two dyes are prepared by dissolving in distilled water and by adding one gram of diluted phenol per litre to each solution.
Next are pl-epal-ed paper test pieces that are conditioned in an atmosphere specified in French standard AFNOR Q03-010. Then, a trace is made on each of the faces of the test pieces using the series of coloured solutions. This trace is the set of six crossed lines. An observation is then made on each face of the test piece to determine the number of the most agyLessive solution that does not smear and the number of the most aggressive solution that does not transude the paper. The thus-recorded numbers constitute the results for the test pieces.
According to an embodiment of the invention, the plane fibrous structure is a tamper-proof paper such that when a counterfeiter attempts to erase markings by current methods (sodium hypochlorite, oxydoreducing combination, alkali, acids or solvents) it takes on a colour different to its original colour.
Thus, if the counterfeiter attempts to tear off such a self-adhesive security paper, he tears off the substrate and/or the information medium;and if he attempts to erase the markings to insert another, the tamper-proof paper forming the information medium becomes stained.
05 Preferably, the information medium includes threads or fibres within its bulk, these being for example fluorescent. It can also include interrupted patterns i.e. tiny confetti or light, dark or greyish watermarks.
The paper can be a tamper-proof paper of the type already disclosed and protected by the European patent application EP-A-O 174 885 filed by the applicant. It can also include a coloured layer obtained by layerîng the paper on one face~ the layering soup being coloured by a dye reactive to acids, alkali or even water.
Preferably, the adhesive used is an acrylic adhesive in an aqueous, reticule emulsion. This adhesive must possess all three sf the following main characteristics : good adhesion, good tack (instantaneous glueing capability) and good internal cohesion. This adhesive can be obtained by mixing an acrylic copolymer of the ACRONAL V 20 ~, sold by BASF, which gives tack, an ACRONAL 290 type acrylate, sold by BASF, and a DERMULSEN 51 ~ type colophane in emulsion, sold by DRT (France); the last two components providing adhesion and internal cohesion. The relative quantities of these components shall be determined by the man of the art according to the characteristics required for the end product. There can also be added rheology regulating additives which are commonly used by the man of the art.
ACRONAL V 20 ~ is an anionic aquaeous dispersion of an acrylic ester copolymer with carboxylic groups. It contains 70 + 1%
of dry extract.
ACRONAL 290 ~ is an aquaeous dispersion of an acrylate and styrene copolymer. It contains 50 + 1% of dry extract.
DERMULSEN 51 ~ is an aquaeous dispersion of a modified colophane, with 55 ~ 1% of dry extract.
The following description with reference to the appended drawings shall give an understanding of how the invention can be put into practice.
- Figure 1 is a three-quarter view of an embodiment of the self adhesive tamper-proof information medium according to the 05 invention.
- Figure 2 is a three-quarter view of the information medium of Figure 1 which has been printed over.
- Figure 3 is a view along the line M of the information medium shown in Figure 2.
lû - Figure 4 shows an information medium according to the invention~ placed on a substrate, eg. page from a passport.
The self-adhesive tamper-proof information medium according to the invention, shown in Figure 1, has a flexible, printable, planar structure 2 that can be formed from cellulosic and/or synthetic fibres. This planar structure 2 can also be formed from any other printable matter provided that it be more or less porous. The planar structure 2 is covered with an adhesive layer 3. The essential characteristic of the information medium according to the invention is that the planar structure is a sheet that allows partial pene~.a~ion of the adhesive into the thickness of the planar structure.
According to the inventi.on, the planar structure, which can be made of paper, has two further characteristics. First, the adhesive 3 is made such that when the self adhesive medium 1 is placed on a substrate 4 (Figure 4), eg. on a page of a passport 5, the mechanical removal of the medium 1 brings about a delamination and tearing of the substrate 4 and/or the planar structure 2. Thus, a counterfeiter attempting to recuperate a passport 5, and in so doing tries to remove the self adhesive medium 1I would delaminate the substrate 4 and thus the page of the passport 5. The latter would then no longer be reusable. The counterfeiter would also delaminate the planar structure 2 which could then no longer be placed on a substrate 4 again.
The self adhesive medium 1 can have a planar structure 2 that is the tamper-proof paper. The term tamper-proof paper is taken to mean paper that includes threads or fibres in its bulk, eg.
fluorescent threads or fibres, and interrupted patterns or watermarks. Such types of paper are difficult for a counterfeiter to reproduce.
The Figures show a planar structure 2 that is a 05 tamper-proof paper that contains a watermark 6. Also, in Figure 3 is shown a planar structure 2 which is a tamper-proof paper that includes a security thread 7.
According to one embodiment, the planar structure 2 is a tamper-proof paper such that when an attempt is made to erase printing by sodium hypochlorite or an oxydoreduction combination of the "Corector" type, or acids, alkali, solvents etc., it takes on a colour different to its original colour.
Indeed, this planar structure 2 is intended to receive print 8, eg. a stamp. The problem is thel-erore to prevent counterfeiters from attempting to erase and/or alter this stamp 8.
Thus, when the planar structure 2 is submitted to chemical action, it can take on a colour different to its original colour.
The planar structure 2 or security paper 6 can also include a surface-coloured layer, eg. a layer deposited by a class;cal layering device.
Finally, the self-adhesive medium according to the invention can be provided with an anti-adhesion coating 9 placed over the adhesive 3.
The self-adhesive tamper-proof medium 1 is used as follows :
the medium 1 (Figure 1) is printed over so as to have a motif 8, eg. a visa. Next, the user unsticks the anti-adhesion covering 9 and sticks the medium 1 on the subs~ e 4 which is a page of the passport 5. It can thus be seen that the motif 8 is external and is not contained between the subx~l-a~e 4 and the plane fibrous structure 2.
Preferably, a heat resistant adhesive 3 is used.
Moreover, the adhesive 3 can be chosen to provide a maximum adhesion to the fibrous structure 2 on the substrate 4 of the passport within a maximum period of 5 hours, but preferably the adhesive is chosen to provide sufficiently high adhesion in a few minutes. Indeed, the planar structure 2 or sheet of paper must rapidly adhere to the substrate 4. Thus, when a counterfeiter attempts to remove the planar structure 2 from the substrate 4, after a few hours, the sub~ a~e delaminates and likewise the û5 fibrous structure delaminates. These parts cannot therefore be reused by a counterfeiter.
The self adhesive tamper-proof information medium 1 according to the invention is plepaled in the fo~lo~;ng manner.
COMPARATIVE EXAMPLE
An adhesive is prepared in an aquaeous emulsion having the fûllowing composition. Quantities are expressed in terms of weight.
- ACRûNAL V 205, sold by BASF, approximately 70% dry extract 78 - ACRONAL 29û D, sold by BASF, approximately 50% dry extract 22 - DERMULSEN 511, sold by DRT (France) approximately 55% dry extract 5 The adhesive thus obtained in an aquaeous dispersion is deposited on an anti-adhesion paper. After drying, the planar structure is stuck thereto by pressure. This planar structure is a tamper-proof paper such as described above.
If the thus-obtained product is cut out and stuck on a substrate 4, eg. a page of a passport, an attempt at mechanically removing the planar structure will not result in the delamination of that plane structure, but the adhesive will separate from the substrate.
Thus, this preparation mode does not achieve the aim sought for by the invention. Indeed, the adhesive mass could not 0 penetrate sufficiently into the thickness of the planar structure.
EXAMPLE ACCORDING TO THE INVENTION
Use is made of an acrylic adhesive in the previously-obtained aquaeous dispersion, deposited on a fibrous planar structure 2 to obtain a layer of between 20 and 45 9 of adhesi~e sec/m of planar structure 2. This planar structure 2 is pl-erel-ably a tamper-proof paper having a grammage of 659 m2. Then, after drying of the adhesive mass, an anti-adhesion paper is glued against the planar structure 2. When using such a self-adhesive information medium, i.e. when removing the anti-adhesion paper, 05 and then glueing the planar structure 2 on a su~L-a~e 4, there results a delamination of that structure and/or substrate 4.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. Self-adhesive tamper-proof medium intended to be placed on an organic substrate, wherein it is formed of at least one printable, tamper-proof planar structure covered with a pressure-sensitive adhesive layer, which is partially absorbed in the thickness of the planar structure, the planar structure and the adhesive being such that the self-adhesive tamper-proof medium cannot be removed from the substrate without at least partial destruction of the substrate.

2. A self-adhesive medium according to Claim 1, wherein the adhesive layer is partially absorbed within approximately one third of the thickness of the planar structure.

3. Self-adhesive medium according to Claim 1 or 2, wherein the planar structure is a sheet of natural and/or synthetic fibres whose sizing degree is equal to 5.

4. Self-adhesive medium according to Claim 1 or 2, wherein the structure is a sheet of tamper-proof paper having security means chosen among security threads and fibres, interrupted patterns and watermarks.

5. Self-adhesive medium according to Claim 1 or 2, wherein the planar structure is a paper that takes on a colour different to its original colour if it is submitted to the action of an alkali, an acid, an oxydoreduction couple, water, sodium hypochlorite, or solvents.

6. Self-adhesive medium according to Claim 1 or 2, wherein the planar structure includes a coloured layer that is reactive to the action of an alkali, an acid or water.

7. Self-adhesive medium according to Claim 1 or 2, wherein the adhesive is an adhesive that allows the adhesion of the planar structure on the substrate in a time period from a few minutes to five hours.

8. Self-adhesive medium according to Claim 1 or 2, wherein the adhesive is overlaid with an anti-adhesion sheet.