ES2214005T3 - DOCUMENT WITH RASCABLE LAYER THAT PREVENTS FRAUDULENT READING. - Google Patents

Abstract

The printed document, e.g. a lottery scratch card on which confidential information (2) printed on a base layer (1) is masked by an opaque scratch-off layer (4), has an outer surface layer (5) containing thermochrome pigments which react to a variation in temperature by a reversible change in colour. The pigments can be incorporated in the scratch-off layer (4) itself or in another layer (5) immediately adjacent to it, and this can be covered by an additional overprinted layer (6). When exposed to a temperature of some 25 deg C or e.g. ultraviolet light, an even colour change indicates that the scratch-off layer has not been disturbed. An uneven colouration indicates possible tampering.

Description

Document with scratch-resistant layer that prevents reading fraudulent

The invention relates to printed documents that have confidential information masked by a opaque scratch coat. Normally this information can only be revealed after destruction by scratching said layer.

This category of documents includes in particular game tickets called "lottery instant ". In these games, the buyer of a ticket can know immediately the winning nature or not of your purchase scratching the layer, operation that discovers the message or number concealed below. Said scratchable layer can also be used. in different types of documents - such as: gift voucher, voucher commercial, etc. - which give rise, for example, to the delivery of a prize or a gift based on a message, a number, a icons, revealed by scratching the opaque layer.

Any document that contains a part of information whose confidentiality the issuer wishes to guarantee, such as a secret code to communicate to a person In particular, it can also be provided with a scratchable layer.

The common peculiarity of all these types of documents is that the total or partial absence of the scratch coat must clearly reveal if the underlying message has been eventually discovered. If this layer is altered when the document reaches its normal recipient, it is that the document secret has been violated, no doubt with a purpose fraudulent.

It is essential that in these documents the Integrity of the scratch coat can be easily checked. Even the absence of tiny parts of the layer can be enough for the scammer to know what a message needs hidden from a code. It is therefore convenient that the document be conceived so that even the alteration of a very small part of the layer is sufficiently visible and evident to wake up the suspicions and evidence of such fraud.

Likewise, the conception of said documents must be such that it is impossible, or as little difficult, to remove partial or completely scratch the layer to know the hidden message, to reconstitute it then, or even apply a new coat scratchable so that the document appears intact and fraud non-existent.

FR-2 595 987 describes an opaque layer made with a brittle ink, covered by a complicated printed drawing, such as a guilloche, so that the scammer will act by removing and replacing the layer, had to take the delicate work Supplementary to reconstitute the original overlay drawing.

WO 9640394 is known as a multilayer printing procedure that supposedly prevents reproduction after layer alteration scratchable

WO 95/14579 part of another approach to the problem: crucial information is only printed on the document in the moment of the sale, by means of a thermal procedure Controlled by a central computer.

According to other techniques, the ink that covers the information can react with certain solvents, so that any attempt to detach the layer is detected easily.

Intermediate document WO 005080A describes a series of optional methods and in particular the presence of a thermochromic layer, to prevent fraud. This document, without However, it does not provide, in particular, the combination of several layers With particular optical effects.

There are numerous examples of application of principles stated above. Unfortunately, the practice still shows fraudulent manipulations: the skill used it has been enough to give the impression that the document is exempt from any scratching. It follows clearly for the issuer of the document the disclosure of information theoretically confidential, or, in the case of lotteries, a loss financial added to a disastrous effect on the credibility of The games in question.

An objective of the invention is to obtain some scratch-proof documents in which hidden information be protected against fraud, in particular due to scratching and to the fraudulent reconstitution of the layer that masks this information, overlapping or taking off and relocation of that layer.

Another object of the invention is to obtain some scratch-proof documents that have a more elaborate appearance that of a simple printed image, even complicated, and whose Visual effect be remarkable.

Another object of the invention is that it can be carry out the control at any time in the chain of distribution, without the documents themselves being affected.

The object of the invention is a printed document that has confidential information masked by a opaque scratch layer whose outer face has a layer that It contains pigments that react with a color change reversible in the event of a temperature variation hereafter called "thermochromic layer", in which the pigments are arranged in the same opaque scratch coat and / or pigments are dispersed in a different layer applied on the outer face of the opaque scratch layer, the document comprising an outer layer in overprinting on the thermochromic layer.

Optionally, one of the layers that covers the confidential information includes pigments that have a variable optical effect according to environmental conditions.

This variable optical effect depends, for example, of the angle from which an observer observes the document.

This variable optical effect can be obtained by an irised ink, or by an ink that reacts so reversible against ultraviolet radiation.

Advantageously, this variable optical effect is obtained by fixing a holographic layer.

Advantageously, the temperature at which produces this change is close to that of the epidermis, that is 25ºC approximately.

The object of the invention is also a procedure for manufacturing a document such as the one described previously comprising the following operations:

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fixing on a support of confidential information;

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fixing on by at least a part of this layer information protective;

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dispersion in a layer of an ink that contains pigments that react with a reversible color change in the face of a variation of the temperature;

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fixing on by at least a part of the protective layer of an opaque layer scratchable;

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layer fixation which contains said pigments.

The scratchy opaque layer may be confused and the thermochromic layer.

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fixing on overprinting of a printed outer layer.

This procedure may also include the following operation:

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dispersion in the outer layer of an ink that has a variable optical effect according to the conditions of the environment.

The thermochromic layer may be fixed by silkscreen or flexography. It can also be a layer transferable.

Other particularities and advantages of the invention will become apparent from the following description of a particular embodiment, referring to the attached drawings, in which:

Figure 1 is a perspective view with torn from a document according to the invention.

The document comprises a support 1 on which printed information 2 has been added (in general, a series of figures, figures, icons, etc.).

This information 2 in principle is impossible to decipher without destroying at least partially a layer that the discover in sight or any other means of reading (photography, photocopier, etc.).

Information 2 is covered by a layer protective 3, which separates it from an opaque layer 4, which is equipped with mechanical and physical characteristics such that only It can be removed by deliberate scratching. This opaque layer 4 it is in turn covered by a layer 5 that contains an ink thermochromic As Figure 1 shows, this layer 5 is covered by an outer layer 6, which can have a function decorative

A classic method of scammers consists of know the coveted information by destroying the layer locally scratchable in a series of strategic points (the information being global withdrawal at the same time by interpolation and extrapolation) and then masking the surfaces - which, depending on their ability, they can be extremely reduced - destroyed by their intervention.

With some classic documents, if the scammer is skillful, you can get to mask it practically undetectable altered places. Quite paradoxically, the more complicated the motifs that cover the layer scratchable, the easier it will be, depending on the discontinuities in the color or in the strokes, conceal his intervention. Conversely, about Very simple reasons can be masked by a state of uniform surface.

All known protections act therefore as "passive" protections.

The document according to the invention acts, at on the contrary, as an "active" protection due to the presence of motifs made with the help of thermochromic pigments. The particularity of these pigments is that they act quickly with visible color changes before a variation of the temperature.

In the present case, it is sufficient that the legitimate recipient of the document exposes it to a change of temperature: if the entire surface of the document or the motive presents a concordant color change, you can deduce that The confidentiality of the information that has been sent to you has been  respected If, on the contrary, some zones or points located retain their original color, or even have a discordant variation, you must deduce that the document has been counterfeit.

No complex instrument is needed to proceed to this check: it is sufficient to put the document in skin contact, for example by applying a finger on it.

If the counterfeit areas retain their color or original tone, it can be deduced that the document has been forged with the help of classic pigments, which do not They react to a temperature variation.

The presence ( a priori unlikely) of counterfeit areas that present a discordant variation would indicate that the scammer, despite its high cost and restricted diffusion, has been able to obtain thermochromic pigments.

However, the variety of features that can be applied to these pigments (in particular by mixing) leads to a practically zero probability rate the color matching with a series of prints determined.

Being this color variation reversible, it is possible non-destructive, punctual or large scale, at any point in the distribution chain, keeping the controlled documents all their integrity.

As shown in Figure 1, the layer thermochromic 5 may in turn be covered by a layer overprinted 6, consisting for example of a difficult guilloche reconstruction after alteration. This overprint is done generally offset.

It will be noted that the presence of a layer of overprint 6 is not essential, but that allows however produce interesting cross effects in association with the thermochromic layer 5.

According to a first printing procedure, the Scratchable layer 4 is applied by screen printing.

The polyester gauze used for this procedure must have a mesh length of 50 µm at least, and preferably between 60 and 80 µm.

Therefore, in principle a silk of 77 to 100 threads / cm.

In this procedure, you can use inks with variable optical properties OVI SICPA (which produce in particular a variation from gold to green).

You can also use some inks transparent iridescent (from violet to green), some semi-transparent inks with two shades (which pass for example from blue to green) or iridescent semi-opaque inks (which pass from gold to beige). All these inks produce a color variation according to Your angle of observation.

Thermochromic inks are water based and must be applied homogeneously by wefts of 77 threads / cm of density. These inks generally change color in some intervals of 25, 30 and 47 ° C (for example, some blue inks whose color change threshold is set to 20 ° C).

They can be used to make the other layers some photochromic inks: the latter have a color change after being exposed to UV radiation (in particular, with a wavelength of 350-370 nm at a rate of 3 mW / cm2). It's enough a few seconds to produce said Color change, which persists for several minutes.

According to another embodiment, recourse has been made to a flexographic printing procedure. Flexography is a lithography form in which the plate is flexible. It can use for example a Nyloflex FA plate (BASF®). To transfer enough ink (so that you get a uniform distribution), several overlapping layers can be pressed. This procedure applies to both variable and inks. for the thermochromic or photochromic inks described previously.

It is also possible to apply the scratch coat described above using a hot transfer or cold

A transfer machine, such as the machine Gietz® allows to transfer a layer 5, 6, by a combination of pressure and heat, on the scratch layer 4.

A pressure of the order of 200 is used kg / cm2 and a temperature of approximately 125 ° C. Speed of transfer does not exceed a cadence of 3600 documents per time. The clichés used are made of steel; the sheet used is, for example, a simple gold or silver leaf.

You can transfer them in the same way holograms, cinegrams or other diffraction layers on the scratch coat 4.

According to a variant not shown in the figure 1, thermochromic pigments are dispersed in the same layer scratchable 4, and not in a different layer 5.

The amount of pigments, in this case, is obviously more important since the layer is thicker and since colors should appear despite the load opaque

Claims (12)

1. Printed document that has confidential information (2) masked by an opaque scratch layer (4) whose outer face comprises a layer (5) that contains thermochromic pigments, which react with a reversible color change to a variation of the temperature characterized in that the pigments are arranged in the same opaque scratch layer (4) and / or said document comprises an overprinted outer layer (6) on the layer containing the thermochromic pigments. 2. Document according to claim 1, characterized in that one of the layers (4, 5, 6) that cover the confidential information comprises pigments that have a variable optical effect according to the surrounding conditions. 3. Document according to claim 2, characterized in that the variable optical effect depends on the angle from which an observer observes the document. 4. Document according to any of claims 2 and 3, characterized in that the variable optical effect is obtained by an iris ink. 5. Document according to any of claims 2 to 4, characterized in that the variable optical effect is obtained by an ink that reacts reversibly to ultraviolet radiation.
ta. 6. Document according to any of claims 2 to 5, characterized in that the variable optical effect is obtained by fixing a holographic layer. 7. Document according to any of the preceding claims, characterized in that the color change of the pigments is carried out at a temperature of approximately 25 ° C. 8. Method of manufacturing a document according to any of the preceding claims, characterized in that it comprises the following operations:

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fixing on a support of confidential information (2);

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fixing on by at least part of this information (2) of a layer protective;

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dispersion in a layer (4, 5) of an ink containing pigments thermochromic;

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fixing on by at least a part of the protective layer of a scratchable opaque layer (4);

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layer fixation (4, 5) that contains these pigments, and the opaque layer (4) and the layer (4, 5) containing the pigments thermochromic;

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fixing on overprinting of a printed outer layer (6).

9. Manufacturing method according to claim 8, characterized in that it further comprises the following operation:

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dispersion in the outer layer of an ink that has a variable optical effect according to the conditions of the environment.

10. Manufacturing method according to any of claims 8 and 9, characterized in that the layer containing the thermochromic pigments is fixed by screen printing. 11. Manufacturing method according to any of claims 8 to 10, characterized in that the layer containing the thermochromic pigments is fixed by flexography. 12. Manufacturing method according to any of claims 8 to 10, characterized in that the layer containing the thermochromic pigments is a transferable layer.