EP1436774A1

EP1436774A1 - Valuable document and security mark using a marking substance

Info

Publication number: EP1436774A1
Application number: EP02781215A
Authority: EP
Inventors: Karlheinz Mayer; Dirk Uwe SÄNGER; Jürgen ZERBES
Original assignee: Giesecke and Devrient GmbH
Current assignee: Giesecke and Devrient GmbH
Priority date: 2001-10-05
Filing date: 2002-10-04
Publication date: 2004-07-14
Also published as: JP2009274448A; CN100476870C; MXPA04002958A; ZA200402086B; BR0213133A; CA2462803A1; US20050052519A1; RU2004114246A; CN1564998A; WO2003032243A1; RU2305866C2; JP2005505444A; PL368057A1; DE10149265A1

Abstract

The invention relates to a valuable document, a security element and a security mark, which contain a marking substance that is absorbent in the infra-red spectral range between 1000 and 2500 nm, but is not significantly absorbent in either the visible spectral range, or at 800 nm. Said marking substance cannot therefore be recognised by the widespread simple IR reading devices, which operate at approximately 800 nm. Preferably, an additional overprint is added, which is absorbent in the visible spectral range and also at approximately 800 nm, but not in the 1000 to 2500 nm range. According to the inventive method, for verification the marked location is irradiated with infra-red light in the 1000 to 2500 nm range and the absorption is determined.

Description

Valuable document and security marking with marking material

The invention relates to a document of value, a security element and a security marking which have a marking substance which absorbs in the infrared spectral range, which shows no significant absorption in the visible range and is preferably largely transparent, as well as an examination method and a device for carrying out the examination. With such marking materials, for example introduced in printing ink, markings can be produced on any objects or their packaging, which are preferably used for authenticity checking or in the field of logistics, for example for recording and tracking the flow of goods.

A security code is known from EP 0340 898 B1, which has two identification marks. An identification mark is essentially colorless and absorbs in the near infrared part of the electromagnetic spectrum from 700 to 1500 ran. This first marking is overprinted with a second color marking, which is opaque in the visible range and does not absorb in the infrared spectral range mentioned. The marking absorbing in infrared is detected with a reader that works at 780 to 800 nm. Such readers, which work with commercially available and inexpensive silicon detectors, are now widespread and accessible to everyone. The visually invisible markings known from the prior art, which absorb around 800 nm in the working range of common silicon detectors, therefore have the disadvantage that the portion of the marking which is actually supposed to remain hidden from the human eye has no particular problem for unauthorized and uninitiated persons Difficulty is accessible.

The object of the present invention is therefore a possibility for marking and a method for testing objects and in particular to propose documents of value that meet further security requirements without having the disadvantages of the prior art.

This object is achieved by the subjects and the method with the features of the independent claims. Further developments and preferred embodiments are set out in the subclaims.

The documents of value, security elements and security markings according to the invention are distinguished by a marking substance which has a significant absorption in the infrared spectral range from 1000 to 2500 nm. In the visible spectral range, on the other hand, the marking substance has no or only a weak intrinsic color and therefore shows no significant absorption in this part of the spectrum. The marking substance also shows no significant absorption at a wavelength of or around 800 nm.

The marking substance has the advantage that it cannot be detected with the widespread and inexpensive silicon detectors, which operate in the range from approx. 780 to 800 nm.

In addition to organic compounds, inorganic materials are used as IR absorbers according to the present invention, which have a better stability against environmental influences. Those absorbers based on doped semiconductor materials are preferred. Metal oxides which are also distinguished by their aging resistance are particularly preferred. The marking substance is preferably present in an average particle size which is less than 50 nm. As a result, visible light is hardly scattered by the particles. The marking substance is colorless or has only a very weak intrinsic color.

The marking substance is preferably applied to the value document in the form of an imprint. The marking substance is added to a binder or a printing ink mixed with color pigments. The printing ink or the binder must not have any significant absorption in the infrared range from 1000 to 2500 nm, in particular 1500 to 2000 nm. The print image to be displayed with the marking substance is arbitrary and can be, for example, a logo, alphanumeric characters, a bar code or the like.

However, it is also possible to apply or incorporate the feature substance absorbing in the infrared directly onto a value document. The methods described in EP-A-0 659 935 and DE 101 20818 are suitable for this purpose. The pigment particles used to mark a document of value are mixed with a gas stream or a liquid jet and introduced into a paper web. These methods are particularly suitable for marking so-called security paper, such as is used for the production of banknotes, for example. It is also possible to add the marking substance to a coating slip or to apply it together with surface sizing to the surface of a value document or to the substrate materials used for its production. In addition to paper and similar fiber-containing substances, foils into which the feature substance can be incorporated are also suitable for the production of value documents. The process of coextrusion is particularly suitable for this in film production. It can also be used to produce foils that only contain the marking substance in certain sections or strips. The marking substance is preferably not applied or applied over the entire area, but only at selected locations or along predetermined tracks. Coding can be generated through targeted recesses or interruptions in the application or application of the marking substance. Such codes can be used, for example, to reproduce batch numbers, lot sizes or product or manufacturer names.

Value documents in the sense of the invention are understood to mean in particular bank notes, but also other monetary documents, such as checks, shares and vouchers. Identity cards and identification documents are also counted. Such documents of value are often provided with an individual serial number. In the value documents according to the invention, the serial number is preferably displayed in addition to a visually visible representation or exclusively by means of the marking substance absorbing in the infrared. The so-called non-impact printing processes are particularly suitable for this. For the reproduction of characters that do not change for a large number of documents, other printing methods, such as offset printing, are also suitable.

The area of a document of value provided with the marking substance can remain free or can be combined with a visually visible marking to be explained in more detail below. In particular, if the area provided with the infrared absorbing marking substance remains free and this has a slight intrinsic color in the visible, it can be advantageous to color the value document in the color or the color tone of the marking substance. A further advantageous possibility for camouflaging and disguising the marking can consist in that the area provided with the marking substance is additionally coated with a layer of paint or to provide a thin cover film. Such an additional covering layer must then be sufficiently transparent both at 800 nm and in the selected measuring range, which can be between 1000 and 2500 nm.

According to a preferred embodiment, the document of value can have a security marking which consists of at least a first imprint, which absorbs significantly in the visible and at 800 nm and has no significant absorption peaks between 1000 and 2500 nm, and a second imprint, which is visible and at 800 nm has no significant absorption, but is significantly absorbed in the spectral range from 1000 to 2500 nm.

In a further preferred embodiment of the security marking, the first and the second imprint are arranged to overlap at least in regions.

The security marking according to the invention has the advantage that it is not accessible with the widespread and inexpensive silicon detectors operating at approx. 780 to 800 nm, since only the imprint is recognized in this spectral range, which due to its absorption in the visible can be recognized even without technical information Aid and is recognizable with the normal human eye. The marking formed by the second imprint remains hidden in such a measurement since it has no significant absorption at 800 nm. The second marking is only accessible in the spectral range of> 1000 nm, since only in this range is there any appreciable absorption. The infrared range from 1000 to 2500 nm is of particular interest for the purposes mentioned, since it has advantages in terms of measurement technology. The range from 1500 to 2000 nm is particularly preferred. For a significant absorption in the visible spectral range, which is between approx. 400 nm and approx. 760 nm, it is not necessary that the imprint absorbs in the entire spectral range. Sufficient and effective absorption is also present if absorption is only carried out in a subinterval of the visible spectral range. The corresponding imprint is then easily visible and recognizable to the normal human eye under normal lighting conditions and normal viewing distance. However, the visually visible marking can also be checked mechanically using appropriate optical devices, such as scanners or photodiodes, which operate at a suitable wavelength.

The same applies to the invisible infrared spectral range. Significant absorption in a sufficiently wide interval in which the check can then be carried out is sufficient. An absorption is always considered significant if it can be perceived or measured visually or mechanically without special efforts or particularly complex measurement measures. If the absorption of the visually visible imprint is less than 40%, in particular less than 30% of its absorption value at 800 nm, it is considered to be no longer significant.

The same applies to the second imprint, the absorption of which is not significant if it is less than 40%, in particular less than 30% of the value which it has at the wavelength between 1000 and 2500 nm at which the infrared test is carried out.

The absorption of an imprint is usually caused by colorants admixed with a binder, which are present either as soluble dyes or pigments. However, it is also possible that the binder contributes significantly to the absorption behavior of the print. Binder and colorant are the essential components of a printing ink with which the prints forming the security marking can be produced.

Both the first and the second imprint can form a closed surface or can be interrupted. Designs are preferred in which additional information is reproduced by the respective imprint. This can consist, for example, of a logo, a national emblem, a lettering or other alphanumeric characters or display an image. The execution as a barcode, with which information can be represented in encrypted form, is particularly preferred. Execution as a two-dimensional barcode is also possible.

The camouflage and concealment of the second print by the first is particularly efficient when the first and the second print are printed on essentially the same area, i.e. are congruent. However, only partially overlapping arrangements are also suitable. Regardless of the order in which they are arranged and positioned relative to one another, the two imprints can have any shape. They can be symmetrical and / or asymmetrical. The contour of the two prints can be the same as well as different.

All suitable printing methods can be used to generate the prints. However, the ink jet method is particularly preferred since it is a contactless printing method with which, for example, non-flat and curved surfaces can also be printed without particular difficulties. It is also particularly suitable Way to create individual, changing prints, such as a serial number.

The security marking according to the invention can also be applied to packaging and wrappings, such as cardboard boxes and foils, or can be printed on a tag or label, a seal or a banderole and then subsequently connected to the object which is actually to be protected. An embodiment is also preferred in which the security marking is generated as an intermediate carrier on a transfer belt and from there onto a belt to be protected or identified

Subject is transferred. The attachment of the security marking on deposit containers, such as bottles or cans, is particularly preferred, the security marking according to the invention also having the function of a token.

The security marking according to the invention is advantageously used wherever the authenticity of an object or document is to be checked. Their use is also advantageous in the field of logistics, since information contained in the marking can be queried when the marking is checked at different “security levels”. For example, first information may be visually visible, but coded as a barcode, while second information , which can be identical or different to the first, is only accessible when measuring in the infrared range of> 1000 nm. The second information can also be additionally coded, for example as a bar code.

Preferred applications of security marking for documents concern documents of value, such as checks and vouchers, admission tickets, Lottery tickets, ID documents, such as passports, company or ID cards, accompanying documents, such as delivery notes, certificates of authenticity and customs papers.

For the first print, which is significantly absorbed in the visible and at approx. 800 nm, but not above 1000 nm, printing inks come into consideration, for example, to which CI Bluelδ and / or Green 7 has been added as a colorant (CI = Color Index). Printing inks that appear visually black are preferably used, which are produced by subtractive color mixing using red and yellow base colors and one or both of the aforementioned colorants. For example, 2,5-cyclohexadiene-l, 4-diylidene-bis [N, N- bis (4-dibutylanτ ophenyl) amm.omunι] comes as the infrared absorber, which has no effective absorption either in the visible spectral range or at approx. 800 nm. bis (hexafluoroantimonate) into question, which has the empirical formula C62H ₉₂ N ₆ Fι ₂ Sb2. The dyes ADS 990 MC with the empirical formula C32H30N2S4M and are also suitable. ADS 1120 P with the formula C52H44CI2O6, which are offered by Siber Hegner GmbH, Hamburg.

The security marking is preferably checked automatically, ie by machine. Commercially available scanners can be used for this, laser beams of suitable wavelength being preferably used as test beams. Laser diodes are particularly suitable for irradiating the measuring range. The marking substance absorbing in the infrared can be checked, for example, at approximately 1070 or 1550 nm. If the absorption is measured in several different spectral ranges or wavelengths, the tests can be carried out both in succession and at the same time, since they contradict each other. do not influence each other. The absorption of the visually visible portion can be determined, for example, at 630 or 650 nm.

As already mentioned, it is for the visually visible, i.e. imprint absorbing in this spectral range according to the present invention is of particular importance that it also absorbs at or around 800 nm. For the visually visible print, both colored, colored and black printing inks can be used. Black prints are preferred because on the one hand they are particularly widespread for marking objects and also form a particularly strong contrast on light and transparent objects. Black markings are therefore particularly noticeable. A black print is also particularly suitable to hide or hide the print absorbing in the infrared.

In order for the second print, which absorbs essentially between 1000 and 2500 nm, to remain inconspicuous and hidden, it is necessary that it has no significant absorption in the visible spectral range. Substances that are transparent and colorless are preferably used for this. However, there are also substances that have only a weak intrinsic color and therefore cannot be visually apparent or easily hidden. In the case of substances with their own color, in particular, their concentration in the second print should be adjusted so that it has only a weak color in the visible spectral range and still leads to sufficient absorption in the infrared between 1000 and 2500 nm.

The marking substance or the safety marking is usually checked in reflection. If the object to which the marking is applied is sufficiently transparent in the relevant spectral range, can also be checked in transmitted light, ie in transmission. The marking substance is preferably checked at approximately 1070 nm and / or at 1550 nm.

In the inventive combination of the imprints in a security marking in which the two imprints overlap at least partially, but preferably lie completely one above the other, the appearance in the visible spectral range or perceived by measurement or measurement technology is determined almost entirely by the first imprint, while the second portion of the security marking is not perceived here.

Even an examination of the security marking according to the invention with inexpensive and widespread infrared detectors operating at approximately 800 nm does not provide any additional information about the presence or the content of the additional second print, since this does not yet have any significant absorption at 800 nm. With such a measurement with simple aids, only the information that is already accessible in the visible spectral range is reproduced, since the first imprint not only absorbs in the visible spectral range, but also or still at 800 nm. In contrast, the examination of the security marking is carried out between 1000 and 2500 nm , the measurement result is caused by the previously hidden second print, while the first print in this spectral range does not contribute significantly to the measurement result.

The security marking according to the invention could not be realized if normal black standard printing ink was used for the visually visible print, since this usually contains carbon black, which also absorbs above 1000 nm. The printing inks or dyes mentioned in EP 0340898 B1, which absorb in the visible but are not effective above 700 nm, do not lead to this either The effect of the present invention that the visually visible print can also be used as camouflage or to conceal the second print even in the near infrared at approximately 800 nm.

If, on the other hand, a document of value or security element according to the invention is checked, in which the area provided with the marking substance does not necessarily have to be combined with an additional, visually visible marking, a single measurement of the absorption at at least one wavelength that was between 1000 and 2500 nm can in principle be carried out - may be sufficient. It is checked whether the visually essentially invisible marking is present at the checked point. However, a further measurement is preferably carried out at a different wavelength. This is preferably around 800 nm or in the visible spectral range. In this way, imitations can be identified that use, for example, the IR absorbers known from the above-mentioned prior art or very broadband absorbing compounds, for example containing carbon black. The latter would be recognizable both in the measurement of the absorption between 1000 and 2500 nm and in the visible spectral range, while the real marking substance according to the invention can only be recognized in the measurement carried out between 1000 and 2500 nm.

If it is not possible or not desirable to provide a document of value directly with the marking substance or the security marking, these can also be introduced into a security element according to the invention. Such security elements can be manufactured separately and connected to a value document or any other object to be secured at any time, for example via an adhesive layer. The security element is preferred designed as a label, seal, banderole or transfer ribbon or integrated into one. Such prefabricated security elements can be arranged on, for example, a band-shaped carrier and, if necessary, can be transferred from this to an object to be protected.

The value documents and security elements according to the invention can have other elements that are difficult to imitate, such as watermarks, security threads, diffraction structures or other so-called feature substances, in order to increase their security against forgery. These feature substances are preferably substances which have luminescence or are magnetic or are electrically conductive. These additional security features are advantageously checked during the authenticity check of the marked objects and documents. According to an advantageous embodiment of the invention, a further print or the first print absorbing in the visible additionally contains these feature substances. Due to their special physical properties, the feature substances make it possible to check the print, in particular for further mechanical testing, using appropriately designed sensors.

Further features and advantages of the invention emerge from the drawing and its description below. Show it:

1 is a document of value provided with marking material,

2 shows a document of value with marking substance along a track,

3 shows a detail from the cross section of a value document, 4 shows a detail from the cross section of a document of value with a coating,

5 shows an object with a security marking imprinted according to the invention in cross section,

6 shows a document with a security marking in supervision,

Fig. 7 is a label in cross section.

1 shows a simple embodiment of a value document 1 according to the invention. This can be a bank note, for example. In a defined area 2 of the value document 1, the document contains a marking substance which is absorbing in the infrared but is essentially invisible visually. The marking substance can, for example, be contained in a printing ink and printed on the value document 1. Other coating or transfer processes are also possible. The area 2 in which the marking substance is present is formed in FIG. 1 as a simple, unstructured surface. However, the marking substance can preferably also be applied in a structured form, for example as a pattern, symbol or barcode. The areas 2 provided with the marking substance can also represent alphanumeric characters which represent, for example, the serial number of the document.

In FIG. 2, the areas 2 containing the marking substance are arranged along a predetermined track 3. The trace with the marking substances is not continuous and continuous, but is interrupted by areas in which no marking substance is present. Due to the location, length and spacing of the areas 2, for example encoded information can be reproduced. This information can, for example, reflect a batch number, the name of the manufacturer or the value of the document, in particular the value of a banknote. The areas 2 can contain the marking substance only on the surface of the value document 1 or also in its volume.

An example of this is shown in FIG. 3. It schematically shows a section of the cross section of a value document 1. It is predominantly formed from fibers 4, which can be paper and / or plastic fibers. Individual particles 5 of the marking substance are embedded in an irregular distribution in the fleece-like fiber matrix. In particular, the representation of the size of the particles 5 is not to scale. The particles can be added to the paper or fiber mass before the sheet is formed or, for example, can be introduced into the fiber matrix after the layer formation using the methods described in EP-A-0659 935 and DE 101 20 818. The concentration of the particles can vary in the value document 1 and, as shown for example in FIG. 2, can be specifically changed along one direction.

A further possibility for equipping a value document with a marking substance is shown in FIG. 4. The document of value 1 consists of a core layer 7, which is formed, for example, by a paper or plastic substrate, the upper and lower surfaces of which have been provided with a coating 6. This coating can be, for example, a coating slip, surface sizing, a top coat, a lacquer layer or a cover film. One of the two outer layers, in the case shown the lower one, was mixed with finely divided particles 5 of the marking substance. Of course, it is also possible to Apply material on both sides or only partially in one or both of the coatings.

In FIG. 5, an object 8 is shown in cross-section in sub-figures a) and b), which has a security marking 9. In the embodiment according to FIG. 5 a), the first imprint 10, which absorbs in the visible spectral range, is on the outside and above the second imprint 11, which is non-absorbing in the visible, but absorbs in the infrared at> 1000 nm.

In Fig. 5b) the imprints 10, 11 are arranged in reverse order. In Fig. 5b) the first and the second overlap only partially overlap, while in Fig. 5a) they are congruent, ie they have been printed on the same surface. 5a) and 5b), the imprints 10, 11 are shown as continuous layers. However, it is also possible to carry out one or both prints as an interrupted layer or by means of individual segments spaced apart from one another. It is therefore not absolutely necessary that in the areas in which the first and the second overlap overlap there are two layers lying one above the other in the entire overlap area. In particular, in cases where the second imprint 11 still has a weak intrinsic color in the visible, it is advantageous to choose an embodiment according to FIG hides or camouflages. The embodiment variant according to FIG. 5 b), in which the second print 11, which absorbs essentially in the infrared, is on the outside, is particularly preferably used in cases in which the second print 11 is completely transparent and colorless. 6 shows a document 1 in supervision, which bears a security marking 9. The visually visible imprint 10 was imprinted using an inkjet process and is designed as a barcode. It overlaps to a large extent with the surface on which the second IT imprint, which is not visible in the visual, was applied. Since the second imprint 11 only absorbs in the infrared above 1000 nm, but has no intrinsic color in the visual spectral range and is therefore not visible to the naked eye, only the outline of the imprint 11 is indicated by a dashed line in FIG. 6. The visually invisible imprint 11 can also be produced using the ink jet method, but also using another suitable printing method. Imprint 11 can also be designed as a barcode, but can also reproduce other symbols or characters, for example a national emblem or a company logo.

In particular for embodiments which are constructed in principle according to the scheme shown in FIGS. 5a, b and 6, it can be advantageous to provide one or more additional coloring or lacquer layers which can lie above, below or between the two described. Such additional layers must be essentially transparent in the measuring range between 1000 and 2500 nm. With a suitable color or gloss, these layers can serve as additional camouflage for the marking absorbing in the infrared. The additional layers can have the function of a protective layer or a so-called design layer, through which the markings are graphically integrated into their environment.

According to a preferred embodiment, an additional layer or an imprint can be provided, by means of which a marking or a code is represented, which in the range between 760 and 1000 nm represents a significant edge absorption. This makes it possible to implement a “three-stage” marking and safeguarding, each of which has a marking in the visible, in the range from 760 to 1000 nm accessible by conventional means and in the area of maximum security above 1000 nm.

7 shows a cross-section of a label 12 which has the security marking 9 on one surface and is provided with an adhesive layer 13 on the other surface. With the aid of a suitably adapted adhesive layer 13, the label 12 can be attached to any objects. If the label 12 consists of a carrier layer that is transparent both in the visible and in the infrared spectral range, the adhesive layer can also be arranged on the same side as the security marking 9. Both the print 10 and the print 11 are composed of non-contiguous sub-segments, as is the case, for example, with a bar code. The one in this case is outside

Imprint 10 takes up a larger area than imprint 11. Even if ink has not been transferred at every point of the imprint 10, the imprints 10 and 11 overlap, i.e. their printing areas completely. Although not all segments of the inside print 11 are covered by printing ink of the outside print 10, this is not disturbing, since the print 11 has at best a weak intrinsic color in the visually visible spectral range.

Claims

Patent claims

1. Document of value (1) with a marking substance absorbing in the infrared spectral range, characterized in that the marking substance has a significant absorption in the range from 1000 to 2500 nm and has no significant absorption in the visible spectral range and at 800 nm.

2. A document of value according to claim 1, characterized in that the marking substance is applied to the document of value (1)

Ink or a toner is included.

3. Value document according to claim 1, characterized in that the marking substance is introduced into the substrate of the value document (1).

4. Document of value according to claim 3, characterized in that the substrate is essentially formed by security paper.

5. Value document according to one of claims 1 to 4, characterized in that information is reproduced by the arrangement or distribution of the marking substance.

6. Value document according to claim 5, characterized in that the information is encoded.

7. Value document according to claim 6, characterized in that at least part of the information is present as a barcode.

8. Value document according to one of claims 1 to 7, characterized in that alphanumeric characters or symbols are represented by the marking substance.

9. Value document according to one of claims 5 to 8, characterized in that an individual serial number assigned to the value document (1) is represented by the marking substance.

10. Document of value according to one of claims 1 to 9, characterized in that the marking substance comprises doped semiconductor material.

11. document of value according to one of claims 1 to 10, characterized in that the marking substance comprises a metal oxide.

12. Value document according to one of claims 1 to 11, characterized in that the marking substance is present as particles, the average size of which is less than 50 nm.

13. Value document according to one of claims 1 to 12, characterized in that the value document (1) is selected from the following group of documents: banknotes, checks, identification documents, accompanying documents, customs papers, lottery tickets, entrance tickets, vouchers, tokens.

14. Security element for securing objects, which has a marking substance absorbing in the infrared spectral range, characterized in that the marking substance has a significant absorption in the range from 1000 to 2500 nm and bar spectral range and at 800 nm has no significant absorption.

15. Security element according to claim 14, characterized in that it is arranged in a detachable form on a carrier.

16. Security element according to one of claims 14 or 15, characterized in that it is designed as a label, seal, transfer ribbon or banderole.

17. Security marking (9) which has at least a first and a second imprint (10, 11) and the first imprint (10) is significantly absorbent in the visible spectral range, while the second imprint (11) has none or only one in the visible spectral range has weak intrinsic color, characterized in that the first imprint (10) absorbs significantly at 800 nm and has no significant absorption between 1000 and 2500 nm and the second imprint (11) has no significant absorption at 800 nm, but in the spectral range from 1000 to 2500 nm significantly absorbed.

18. Security marking (9) according to claim 17, characterized in that the first and the second overlap overlap at least in regions.

19. Security marking according to claim 17, characterized in that the first and the second imprint (10, 11) are substantially congruent.

20. Security marking according to one of claims 17 to 19, characterized in that the first and / or the second imprint (10, 11) comprises a barcode.

21. Security marking according to one of claims 17 to 20, characterized in that the first print (10) is arranged substantially above the second print (11).

22. Security marking according to one of claims 17 to 21, characterized in that the first and / or the second imprint (10,

11) are printed using an ink jet method.

23. Security marking according to one of claims 17 to 22, characterized in that the first print (10) contains the colorants CI Blue 15 or CI Green 7.

24. Security marking according to one of claims 17 to 23, characterized in that the first print (10) is black.

25. Security marking according to one of claims 17 to 24, characterized in that the second imprint (11) is transparent in the visible spectral range and has no intrinsic color.

26. Security marking according to one of claims 17 to 25, characterized in that the second imprint (11) has substances which are luminescent, magnetic or electrically conductive.

27. Security marking according to one of claims 17 to 26, characterized in that it is in the form of a label (12), seal, one Banderole or a transfer tape is present and which is suitable for transferring the marking (9) to another object or to connect to it.

28. A method for verifying the authenticity of a security element or security marking (9), which comprises:

irradiating the security element or marking (9) with infrared radiation from the wavelength range from 1000 to 2500 nm,

determining the absorption of the security element or marking (9) at at least one wavelength from the range of the radiation.

29. The method according to claim 28, characterized in that the

• ^ Absorption is also measured at at least one wavelength from the visible spectral range.

30. The method according to any one of claims 28 or 29, characterized in that the absorption is also measured at approximately 800 nm.

31. The method according to claim 28, characterized in that the irradiation is carried out by means of laser light.

32. The method according to claim 31, characterized in that the irradiation is carried out by means of a laser diode.

33. The method according to any one of claims 28 to 32, characterized in that a character, pattern or code represented by the marking substance is determined and evaluated by electronic means.

34. Device for carrying out the method according to one of claims 28 to 33, which has means for radiation which emit in the wavelength range from 1000 to 2500 nm and means for determining the absorption at least one wavelength from the range of radiation.

35. Apparatus according to claim 34, characterized in that the means for irradiation has a laser diode.