KR20150116822A - Method for checking the authenticity of a security document - Google Patents

Abstract

(i)
의 가역성 기계발광 화합물을 가지는 최소 하나의 영역을 포함하거나, 상기 영역 내 또는 이러한 영역의 표면에 가역성 기계발광 화합물을 포함하고: R은 1 내지 12개의 탄소 원자를 포함하는 알킬 사슬을 나타내며, 상기 방법은 상기 영역에 자외선 조사를 실시하여 상기 영역 전체를 첫 번째 형광색 (C1) 하에서 육안으로 볼 수 있는 단계를 포함하고, 상기 첫 번째 색 (C1)으로부터 상기 첫 번째 형광색과 다른 두 번째 형광색 (C2)으로 변환시킴으로써 확인되는 상기 문서의 진위성의 드러냄은, 또한 상기 영역을 최소 마찰 또는 기계적 스트레스에 처함이 없이 최소 50℃의 온도까지 상기 최소 하나의 영역을 가열시키는 것으로 구성되는 단계를 포함한다는 사실에 의해 특징지어진다.The method of the present invention relates to a method for verifying the authenticity of a security document, in particular a trust document,

(i)
Wherein R comprises at least one moiety having a reversible mechano-luminescent compound, or comprises a reversible mechano-luminescent compound in the region or on the surface of such region: R represents an alkyl chain comprising from 1 to 12 carbon atoms, (C2) different from the first fluorescent color (C1) from the first color (C1) by irradiating ultraviolet light to the region, so that the entire region can be visually observed under the first fluorescent color , The disclosure of the authenticity of the document as identified by the fact that it comprises the step of heating the at least one zone to a temperature of at least 50 DEG C without subjecting the zone to minimal friction or mechanical stress .

Description

METHOD FOR CHECKING THE AUTHENTICITY OF A SECURITY DOCUMENT

The present invention relates to a method for verifying the authenticity of a secure document.

The present invention is applicable to applications, particularly in the fiduciary industry and more specifically in the manufacture of secure documents.

A representation of a "security document" means a document, e.g., a paper document, which is at least very complex to disable deceptive reproduction and is included / included within the document to ensure authentication ≪ / RTI > means a document that is coated with means that allows the manufacture of the document to be protected or secured.

In the technical field of security documents, prevention against counterfeiting is enforced and particularly achieved by a series of elements either incorporated into or applied to the support.

The above-described security elements are classified according to various security levels. Security is usually divided into three levels.

Luminescent-type security elements are well known to those skilled in the art. Fluorescent, phosphorescent inks at one or more excitation wavelengths are widely used in the security printing field. Also, parts of the apparatus for identifying such inks are well known and used by the general public.

In particular, the use and large scale dissemination of these inks other than in trust printing (prescription, decorative paints, toys, etc.) facilitates their supply through unsecured routes (e.g. the Internet) It makes it easy to fake.

Document US 5,118,349 and WO 2003/053980 describe the use of rare earths in particular.

A certain number of pure organic compounds having the characteristic of mechanochromism have been described in the literature. The above-mentioned compounds have been presented in a recent review (Chem. Soc. Rev. 2012, DOI: 10.1039 / C2CS35016E).

These compounds, "multi-stimuli" compounds that respond to so-called two or multiple stimuli are very valuable and none of them simultaneously have two reversible and unique physico-chemical properties, They do not react simultaneously to the available mechanical fluorochromism and thermofluorochromism. At present, all of the above-described features may be of interest to further make it more difficult to manufacture counterfeit security documents.

For example, diphenyldibenzofulvene (Adv. Mater. 2011, 23, 3261-3265) is a fluorescent green (500 nm) when pure and solid. After mechanical change, this fluorescence disappears. There is thus a loss of fluorescence properties. The green fluorescence is spontaneously recovered at room temperature. The disappearance of fluorescence is also observed when the compound in a pure state is heated to 90 占 폚. To change to an initial green, rapid cooling is required after heating to the melting temperature of the compound (148 DEG C). The above-mentioned properties are incompatible with use as a constituent of varnish for ink or fork.

In fact, it is preferred that the surface of the support (compound + support in the liquid phase) is not heated to a temperature equal to or higher than the melting point of the compound. At such temperature, the compound will be in a liquid phase and will react with the support, i. E. The material to which it is attached, for example. By returning to the solid state (at ambient temperature), the compound can change its structural configuration and lose its properties in the support.

Furthermore, compounds of one family are known from the document WO-A-2011/068537,

≪ / RTI >

The composition containing the compound has a reversible pressure discoloring effect.

Starting with these products, the Applicant has found that the compositions comprising the compounds are suitable for simultaneous two or more of the above-mentioned reversible and unique physico-chemical properties, namely mechanical fluorescence discoloration and thermal fluorescence discoloration, which can be used independently or additionally I suggest the fact.

Thus, the present invention relates to a method for verifying the authenticity of a security document, in particular a trust document,

At least one region having a reversible mechano-luminescent compound, or a reversible mechano-luminescent compound in the region or on the surface of such a region,

R represents an alkyl chain containing 1 to 12 carbon atoms,

Said method comprising the step of irradiating said region with ultraviolet radiation so that the entire region can be visually observed under a first fluorescent color,

The disclosure of the authenticity of the document identified by conversion from the first color to the first fluorescent color and the second fluorescent color further comprises the step of providing the region with the minimum one And heating the area of the substrate.

In accordance with other non-limiting and advantageous features of the present invention, either individually or in any combination:

The temperature applied to the compound is below the dissolution temperature of the compound;

The temperature is comprised between 50 and 250 ° C;

The heating of the zone to the temperature is carried out for a period comprised between 1 and 10 seconds;

The method comprising the step of applying a frictional force to a portion of the region prior to the heating step such that the portion is converted from the first fluorescent color to the second fluorescent color;

- the above-mentioned reversible compounds are present on the surface and are used when the above-mentioned reversible compounds are incorporated in the ink or varnish;

The method is applied to a security document in which the compound is covered by a varnish, the varnish also completely or partially covering the print appearing in such a secure document;

The method is applied to a security document in which the compound is covered by a continuous film of a polymeric material and the continuous film of polymeric material completely or partially covers the print appearing in the security document.

Other features and advantages of the present invention will become apparent upon reading the following detailed description. The invention will now be described with reference to the accompanying drawings,
Figures 1 to 3 are partial top views of the banknote exemplified in various other states corresponding to the method of the present invention.
Figure 4 is a diagram showing other phenomena applied in accordance with the present invention.

The security document present in banknote 1 is schematically illustrated in the front view of Figs. However, this may be another type of security document, such as a visa or a passport. Therefore, this is a simple exemplary implementation.

For reasons of facilitating the reading of figures, only the monetary value of the banknote, in this case a value of "10 " Of course, what is clearly stated on the front will also be effective for the rear face 3.

By convention, all or some of the security measures (holograms, security lines, watermarks, etc.) used in the trust field may be incorporated into these banknotes, but are not spontaneously illustrated above.

As indicated above, the present invention relates to a method for verifying the authenticity of a security document, in particular a trust document,

Wherein R comprises at least one region having a reversible mechano-luminescent compound, or comprises a reversible mechano-luminescent compound in the region or on the surface of such region, and R represents an alkyl chain comprising from 1 to 12 carbon atoms.

Methods for synthesizing compounds of such families are known per se and are described in particular in the above-mentioned document WO-A-2011/068537.

Compositions of the ink or varnish type may be prepared using a colorless or substantially colorless " intaglio "matrix, termed" transparent blanks " in terms of the trade available, notably from SICPA .

These matrices are composed primarily of dry vegetable oils or consist of solvents, resins and additives (fillers, desiccants).

A compound suitable for the above formula I is introduced into such a matrix at a level comprised between 1 and 10% by weight. Well, this level is 5%.

Such inks or such varnishes are then attached to constituent trust papers of banknote 1 according to one of the methods known to those skilled in the art.

In the example of Figures 1 to 3, this is a uniform tint area forming the egg-shaped region 4.

Of course, other types of regions may be considered and the number of these may vary.

Depending on the nature of the structure of compound I (modification of the length of the chain R) and the characteristics of the matrix (intaglio ink, offset ink, varnish), the compound I can have different fluorescent colors under UV irradiation Lt; / RTI >

For example, at a level of 5% by weight, the compound I comprising 12 carbon atoms has a blue fluorescence color in the intaglio ink, whereas the compound I comprising 6 carbon atoms has a It has a green fluorescent color. This color, referred to as C1 in Figure 1, is uniform across the entire varnish or ink.

Such a situation known from the art corresponds to state A of FIG.

In all of the above-mentioned compounds, the fluorescence changes from blue C1 to yellow C2 (Fig. 2) as soon as friction is applied to a portion of the region 4 (e.g., by the edges of a coin, a blunt object, etc.).

Referring to Fig. 4, this corresponds to the conversion from state A to state B. It is therefore possible to indicate "writing" produced by UV irradiation by "writing "

The change in fluorescence is observed only in the mechanically disturbed part. The reversibility of these properties ensures that the "recording" is spontaneously erased within a few seconds at room temperature or by heating (30-50 占 폚), as can be seen in Fig.

According to the present invention, it is possible to further improve the authenticity check of the secure document by applying the step of heating at least the region 4 to a temperature of at least 50 캜.

Indeed, it is possible to induce a change in fluorescence color over the entire surface by applying such thermal stimuli, for the above-mentioned compounds, by providing heat. This is the situation in Fig. 3, which corresponds to the conversion from state A to state C in Fig.

After the heating is stopped, restarting the latter at a temperature in the order of 30 to 50 ° C provides the possibility of returning to state A.

It will be appreciated that although having fluorescence, state C no longer has the characteristic of mechanical fluorescence discoloration. That is, when friction is applied to the region, the region does not cause a color change locally.

Region 4 having the state B (obtained by friction) illustrated in FIG. 4 can be heated (to a minimum of 50 DEG C) to convert to state C. The return to the initial state A is achieved by the above-mentioned low temperature heating step (30 DEG -50 DEG C).

The heating time to this temperature of 50 DEG C or higher is generally comprised between 1 second and 10 seconds.

Of course, it is important that the temperature obtained by Region 4 is below the dissolution temperature of Compound I.

Thus, the melting temperature of the pure product with R = C ₁₂ H ₂₅ is 158 ° C.

This temperature is variable depending on the length of the R group.

The method of the present invention not only affords the possibility of obtaining significant changes in fluorescence color by friction or by providing heat, but also gives the possibility of achieving loss of mechanical fluorescence discoloration characteristics by heating.

In the trust field, applying varnish is common in secure documents, which completely or partially cover the prints and / or other security elements that appear in the document.

In one selectable case, a continuous film of polymeric material is applied to completely or partially cover the prints appearing in the security document.

In both cases, such a coating has a protective function.

As long as the thickness of such a coating is too large, the above-described phenomena are shown despite the presence of the coating.

Substantially, a man or merchant at a distance can observe the fluorescence of the region by UV lamp and can confirm the color change by friction.

A combination of a UV lamp and a heating means may be made available to the bank for application of the method of the present invention.

Such a device may be integrated into an automated machine for classifying banknotes.

Of course, simple tools such as hair dryers or hot guns can be used.

Claims (8)

1. A method for verifying the authenticity of a secure document (1), in particular a trust document,

At least one region (4) having a reversible mechanoluminescent compound of the formula (I), or comprising a reversible mechanoprene compound in or on the surface of such a region,
Wherein R represents an alkyl chain containing 1 to 12 carbon atoms,
The method comprises irradiating the region (4) with ultraviolet light (R) so that the entire region can be visually observed under a first fluorescent color (C1)
The starting content of the authenticity of the document (1), which is confirmed by converting from the first color (C1) to the second fluorescent color (C2) which is different from the first fluorescent color, also allows the region to be subjected to minimal frictional or mechanical stress And heating said at least one zone (4) to a temperature of at least 50 ° C. The method of claim 1, wherein the temperature applied to the compound is less than the melting temperature of the compound. The method of claim 1 wherein the temperature is comprised between 50 ° C and 250 ° C. The method according to one of the preceding claims, characterized in that said heating to said temperature is carried out for a period of time comprised between 1 second and 10 seconds. A method according to one of the preceding claims, comprising the step of applying a frictional force to a portion of said region (4) before said heating step to convert this portion from said first fluorescent color (C1) to said second fluorescent color (C2) . ≪ / RTI > The method according to one of the preceding claims, wherein said reversible compound is present on the surface, characterized in that said reversible compound is contained in an ink or varnish. Method according to one of the preceding claims, characterized in that the method is applied to a security document in which the compound is covered by a varnish, which varnish also completely or partially covers the print appearing in such a secure document (1) . The method of one of the preceding claims, wherein the method is applied to a security document in which the compound is covered by a continuous film of a polymeric material, wherein the continuous film of polymeric material comprises a print appearing on the secure document (1) Lt; RTI ID = 0.0 > completely < / RTI >

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