EP4145426B1 - Security label - Google Patents

Description

FIELD OF THE INVENTION

• eine laserbeschreibbare Schicht mit schwarzem Aluminiumoxid, wobei die laserbeschreibbare Schicht eine Oberseite und eine Unterseite aufweist, die einander gegenüberliegend angeordnet sind und voneinander weg weisen,
• mindestens eine transparente Schutzschicht, die in einer ersten Richtung gesehen vor der laserbeschreibbaren Schicht angeordnet ist, um die laserbeschreibbare Schicht vor äußeren Einflüssen zu schützen, wobei die erste Richtung von der Oberseite zur Unterseite weist, sowie
• eine Kontrastschicht, die in der ersten Richtung gesehen hinter der laserbeschreibbaren Schicht angeordnet ist, wobei zumindest eine der mehreren Schichten als Bruchschicht aus einer spröden Kunststofffolie ausgebildet ist, um eine Zerstörung der zumindest einen Bruchschicht sowie der laserbeschreibbaren Schicht, und gegebenenfalls einer oder mehrerer dazwischenliegender Schichten, bei einer Manipulation oder einem Ablösen des auf einem Untergrund aufgeklebten Sicherheitsetiketts zu bewirken, und wobei die Kontrastschicht als Bruchschicht ausgebildet ist.

The present invention relates to a security label with multiple layers comprising

• a laser-writable layer comprising black aluminum oxide, the laser-writable layer having a top and a bottom which are arranged opposite one another and point away from one another,
• at least one transparent protective layer which is arranged in front of the laser-writable layer when viewed in a first direction in order to protect the laser-writable layer from external influences, the first direction pointing from the top side to the bottom side, and
• a contrast layer which, as seen in the first direction, is arranged behind the laser-writable layer, wherein at least one of the plurality of layers is designed as a fracture layer made of a brittle plastic film in order to cause destruction of the at least one fracture layer and the laser-writable layer, and optionally one or more intermediate layers, in the event of manipulation or detachment of the security label adhered to a substrate, and wherein the contrast layer is designed as a fracture layer.

STATE OF THE ART

Security labels for marking goods are well known and are used in a wide variety of areas of technology. For example, components supplied to the automotive industry are provided with such security labels.

In order to be able to write desired information on these security labels efficiently, it is necessary to It is known to provide a laser-writable layer. Black aluminum oxide is particularly suitable for such a layer, which has a black metallic color due to a substoichiometric oxygen content of the aluminum oxide. In the following, "laser-writable layer" is to be understood as such a black aluminum oxide layer (sometimes also referred to as "black metallization"), unless otherwise stated. A particularly efficient production of films having such a black aluminum oxide layer is known from EP 1522606 B1 known.

Corresponding layers can be "written" by means of laser action, whereby the energy input makes the aluminum oxide layer transparent along the path of the laser beam. The processes responsible for this, which take place due to the energy input, can include evaporation, oxidation, ablation and the like, as can be seen from the US 5766827 A is known. In order to make the trace or writing particularly visible, an opaque, optically contrasting layer can be arranged below the aluminum oxide layer.

A generally desirable property of security labels is the so-called document authenticity, which in particular includes the property that manipulation or even removal of the security label is not possible without leaving traces. In this context, for example, so-called "void labels" are known from the state of the art, which are used to indicate attempts to tamper with objects and packaging, cf. for example the EP 2603910 B1 or the EP 2603911 B1 . With these void labels, a layer structure with at least one release lacquer layer ensures that a previously invisible or invisible security feature appears on the label surface as soon as the void label is removed from the respective substrate. With the security feature These are usually lettering, images, patterns or the like. However, it turns out that a simple combination or additional creation of a laser-writable layer with or to such a void label does not produce a reliably functioning "laser-writable security label", i.e. a security label with a laser-writable layer. During the application or creation of the laser-writable layer, too much energy is typically introduced into the existing layer system of the void label, so that the existing layer system of the void label no longer functions reliably and document authenticity is not guaranteed.

From the US 2019/147775 A1 A film structure according to the preamble of independent claim 1 is known.

From the US 6,066,437 A A laser-writable film structure is known which, in order to ensure security against tampering, has layers with continuous punching lines which cause the said layers to be destroyed in the event of tampering.

From the DE 10 2005 061 124 A1 A label is known in which a second layer of varnish is applied to a thicker (first) layer of varnish underneath, with this thicker layer of varnish being applied as a carrier layer on an adhesive layer. Discrete inclusions made of a polymer are printed on the adhesive layer, whereby the inclusions contain detectable additives. When the label is stuck onto a substrate, the inclusions are imprinted on the layers above, so that the surface of the label has optically visible and tactile impressions of the inclusions. When the label is removed by force, the inclusions, together with the detectable additives, remain partially in the adhesive, which is why an expert must determine the missing inclusions or the missing detectable additives can be used to determine whether such a label has already been removed and thus re-glued.

From the US 5,770,283 A A label is known whose structure includes an upper visible side and an interrupted separating layer that is printed on the underside of the visible side, as well as an adhesive layer that ensures that there is a strong adhesive force between the visible side and an underlying contrast layer. The label also has a pressure-sensitive adhesive layer on its underside, with which the label is stuck to a substrate. When the label is removed, the upper visible side detaches from the separating layer in the area of the separating layer, so that indirect contact between the visible side and the contrasting layer is lost in the area of the separating layer. In those places where the adhesive layer is glued to the underside of the visible side without an intervening separating layer, the indirect connection between the visible side and the contrasting layer is maintained by means of the adhesive layer. In this way, when the label is removed from a substrate, tamper-proof symbols, figures and the like can be created.

TASK OF THE INVENTION

It is therefore an object of the present invention to provide a laser-writable security label which overcomes the disadvantages described above and ensures document authenticity.

PRESENTATION OF THE INVENTION

• eine laserbeschreibbare Schicht mit schwarzem Aluminiumoxid, wobei die laserbeschreibbare Schicht eine Oberseite und eine Unterseite aufweist, die einander gegenüberliegend angeordnet sind und voneinander weg weisen,
• mindestens eine transparente Schutzschicht, die in einer ersten Richtung gesehen vor der laserbeschreibbaren Schicht angeordnet ist, um die laserbeschreibbare Schicht vor äußeren Einflüssen zu schützen, wobei die erste Richtung von der Oberseite zur Unterseite weist, sowie
• eine Kontrastschicht, die in der ersten Richtung gesehen hinter der laserbeschreibbaren Schicht angeordnet ist, wobei zumindest eine der mehreren Schichten als Bruchschicht aus einer spröden Kunststofffolie ausgebildet ist, um eine Zerstörung der zumindest einen Bruchschicht sowie der laserbeschreibbaren Schicht, und gegebenenfalls einer oder mehrerer dazwischenliegender Schichten, bei einer Manipulation oder einem Ablösen des auf einem Untergrund aufgeklebten Sicherheitsetiketts zu bewirken, und wobei die Kontrastschicht als Bruchschicht ausgebildet ist, erfindungsgemäß vorgesehen, dass zwischen der laserbeschreibbaren Schicht und der Kontrastschicht zumindest eine weitere Schicht angeordnet ist, wobei die zumindest eine weitere Schicht zumindest eine partielle Trennlackschicht umfasst, und dass die spröde Kunststofffolie der zumindest einen Bruchschicht eine Bruchdehnung von weniger als 20%, bevorzugt von weniger als 15%, besonders bevorzugt von weniger als 10%, aufweist.

To solve the above task, a security label with multiple layers requires comprehensive

• a laser-writable layer with black aluminum oxide, wherein the laser-writable layer has a top side and a bottom side which are arranged opposite each other and point away from each other,
• at least one transparent protective layer which is arranged in front of the laser-writable layer when viewed in a first direction in order to protect the laser-writable layer from external influences, the first direction pointing from the top side to the bottom side, and
• a contrast layer which, viewed in the first direction, is arranged behind the laser-writable layer, wherein at least one of the plurality of layers is designed as a fracture layer made of a brittle plastic film in order to cause destruction of the at least one fracture layer and the laser-writable layer, and optionally one or more intermediate layers, in the event of manipulation or detachment of the security label glued to a substrate, and wherein the contrast layer is designed as a fracture layer, according to the invention, at least one further layer is arranged between the laser-writable layer and the contrast layer, wherein the at least one further layer comprises at least a partial release lacquer layer, and that the brittle plastic film of the at least one fracture layer has an elongation at break of less than 20%, preferably less than 15%, particularly preferably less than 10%.

According to the above, it is not excluded that one or more further layers, in particular protective layers, are arranged above or, as seen in the first direction, in front of the at least one transparent protective layer.

The at least one transparent protective layer does not have to be arranged directly in front of the laser-writable layer, i.e. one or more further layers can be arranged between the at least one transparent protective layer and the laser-writable layer.

The laser-writable layer appears dark, in particular black. The contrast layer serves to generate an optical contrast of the, in particular transparent, inscription in the laser-writable layer. In particular, the contrast layer can be white. The contrast layer does not have to be arranged directly behind the laser-writable layer, i.e. one or more further layers can be arranged between the laser-writable layer and the contrast layer, for example a laminating adhesive layer.

Theoretically, the at least one fracture layer can be formed by the laser-writable layer and/or by the at least one transparent protective layer and/or by the contrast layer and/or by at least one further layer. If the laser-writable layer forms the fracture layer, the aluminum oxide of the laser-writable layer can be applied to a plastic film of the laser-writable layer, which plastic film is brittle or has the desired brittle properties.

The said destruction of the at least one fracture layer and the laser-writable layer, and optionally one or more intermediate layers, comprises breaking or tearing.

Due to its brittleness, the fracture layer is reliably destroyed if the security label is manipulated or removed. According to the above, the laser-writable layer, including any intervening layers, is also destroyed if the fracture layer is destroyed. Document authenticity is therefore ensured.

A characteristic value for the brittleness of a material is its elongation at break. The latter is typically in the range of 10 µm to 100 µm for plastic films with thicknesses of 10 µm to 100 µm, in particular 12 µm to 100 µm, as is commonly used for security labels. of approximately 100% or even significantly more than 100%. For example, a 50 µm thick film made of polyethylene terephthalate (PET) has an elongation at break of 190% in the machine direction and 120% across it. If the elongation at break of the plastic film is more than 60%, in particular more than 80%, there is in any case insufficient brittleness. In order to reliably achieve sufficient brittleness, the security label according to the invention is designed, as mentioned, for the brittle plastic film of at least one breaking layer to have an elongation at break of less than 20%, preferably less than 15%, particularly preferably less than 10%. These elongation at break values apply to the plastic film as such, i.e. considered on its own - without the entire structure of the security label with the other layers.

The brittleness requirement mentioned can be met with plastic films of usual thickness using a wide variety of known materials. Accordingly, in a preferred embodiment of the security label according to the invention, the brittle plastic film of the at least one fracture layer is an acrylate film or a polyvinyl chloride film (PVC film) or a polyurethane film (PU film). Said films are sufficiently brittle per se. Additional embrittlement, for example through targeted UV irradiation, is not necessary. Furthermore, no significant additional embrittlement of the plastic films used usually occurs during the manufacturing process.

As mentioned, the contrast layer on the security label is designed as a fracture layer. This allows extremely compact structures to be created with a minimal number of layers, whereby the contrast layer can be arranged directly or not directly behind the laser-writable layer when viewed in the first direction.

As mentioned, the security label according to the invention is provided with at least one further layer between the laser-writable layer and the contrast layer, wherein the at least one further layer comprises at least one partial release lacquer layer. The at least one further layer can comprise further layers in addition to the partial release lacquer layer, e.g. a layer of laminating adhesive. The partial release lacquer layer is not completely continuous, so that certain symbols or characters can be seen when the security label is removed.
to further increase the authenticity of the document. The partial release coating provides a different level of adhesion between the layers arranged in front of and behind the release coating compared to the adhesion of these layers without an intermediate release coating, in order to cause certain shaped areas to detach when the security label is removed or manipulated and to make the symbols mentioned visible.

Alternatively or additionally, in order to increase the sensitivity of the security label to manipulation or removal, a particularly preferred embodiment of the security label according to the invention provides that at least one further layer is arranged between the protective layer and the laser-writable layer, wherein the at least one further layer comprises at least a partial release lacquer layer. In turn, the at least one further layer can also comprise further layers in addition to the partial release lacquer layer, e.g. a layer of laminating adhesive. Likewise, the partial release lacquer layer is not completely continuous, so that certain symbols or characters are created when the security label is removed in order to (even) further increase the authenticity of the document.

As mentioned, symbols of various shapes can be produced using the partial release lacquer layer. Accordingly, in a particularly preferred embodiment of the security label according to the invention, the at least one partial release lacquer layer has the shape of one or more letters, one or more characters, one or more symbols, one or more lines, one or more guilloches, one or more numbers or one or more lettering. The corresponding shape(s) will be formed when the security label is removed due to the local different detachment of the layers adjacent to the partial release coating layer.

In a preferred embodiment of the security label according to the invention, the at least one protective layer comprises a layer of a UV transfer varnish. This represents a particularly favorable solution in terms of process technology for producing the at least one protective layer.

In this case, a particularly transparent layer made of plastic, in particular PET, or a plastic film, in particular PET film, can initially be provided, which, viewed in the first direction, is arranged immediately in front of the layer of UV transfer varnish and is subsequently removed again (by peeling off) - typically already before the security label is applied.

Analogously, in a preferred embodiment of the security label according to the invention, it is therefore provided that the at least one protective layer comprises a layer of a plastic film, in particular polyethylene terephthalate film (PET film).

Of course, cases are also possible in which the at least one protective layer consists of at least one layer of plastic film, in particular PET film, or is completely formed by it.

In the case of several protective layers, it is conceivable that these layers comprise or consist of different plastic films.

In particular, it can be provided that a protective lacquer layer is applied as the "top" or first layer, which can be arranged above the said at least one transparent protective layer. This protective lacquer layer protects the surface of the Security labels against abrasion and can in particular be slightly matt. The latter reduces the reflection of the surface and can therefore prove advantageous if, for example, a barcode written into the laser-writable layer is to be read by a scanner. Accordingly, in a preferred embodiment of the security label according to the invention, it is provided that the at least one protective layer comprises a layer of a protective varnish or printing varnish.

Furthermore, a layer of a printable adhesion promoter can be provided above the at least one transparent protective layer - and below the protective lacquer layer mentioned. This proves to be advantageous, for example, if the security label is initially delivered to a customer with the layer of adhesion promoter as the top layer, who can then print a logo, for example, on the adhesion promoter layer and then apply the protective lacquer layer mentioned, in particular a matt one.

In a preferred embodiment of the security label according to the invention, it is provided that the at least one protective layer comprises at least one fracture layer. This again makes it possible to achieve a very compact structure. In this case, the fracture layer is preferably arranged directly in front of the laser-writable layer when viewed in the first direction, so that the direct adhesion of the fracture layer to the laser-writable layer results in the highest possible security against the destruction of the laser-writable layer if the fracture layer is destroyed.

As already mentioned, the contrast layer does not have to be located directly behind the laser-writable layer when viewed in the first direction. However, in order to ensure the greatest possible contrast, it is A preferred embodiment of the security label according to the invention provides that the contrast layer is arranged directly behind the laser-writable layer when viewed in the first direction. This guarantees optimal readability of what is written in the laser-writable layer in terms of contrast.

SHORT DESCRIPTION OF THE CHARACTERS

The invention will now be explained in more detail using exemplary embodiments. The drawings are examples and are intended to illustrate the inventive concept, but in no way restrict it or even represent it exhaustively.

Fig. 1

eine schematische Schnittansicht einer auf einen Untergrund applizierten ersten Ausführungsform eines erfindungsgemäßen laserbeschreibbaren Sicherheitsetiketts

Fig. 2

eine schematische Schnittansicht einer auf einen Untergrund applizierten zweiten Ausführungsform des erfindungsgemäßen laserbeschreibbaren Sicherheitsetiketts

Fig. 3

eine schematische Schnittansicht einer dritten Ausführungsform des erfindungsgemäßen laserbeschreibbaren Sicherheitsetiketts

Fig. 4

eine schematische Schnittansicht einer auf einen Untergrund applizierten vierten Ausführungsform des erfindungsgemäßen laserbeschreibbaren Sicherheitsetiketts

Fig. 5

eine schematische Schnittansicht einer auf einen Untergrund applizierten fünften Ausführungsform des erfindungsgemäßen laserbeschreibbaren Sicherheitsetiketts

It shows:

Fig. 1

a schematic sectional view of a first embodiment of a laser-writable security label according to the invention applied to a substrate

Fig. 2

a schematic sectional view of a second embodiment of the laser-writable security label according to the invention applied to a substrate

Fig. 3

a schematic sectional view of a third embodiment of the laser-writable security label according to the invention

Fig. 4

a schematic sectional view of a fourth embodiment of the laser-writable security label according to the invention applied to a substrate

Fig. 5

a schematic sectional view of a fifth embodiment of the laser-writable security label according to the invention applied to a substrate

WAYS OF IMPLEMENTING THE INVENTION

The Figures 1 to 5 show, in schematic sectional views, embodiments of a security label 1 with several layers, which is a "laser-writable security label", ie a security label 1 comprising a laser-writable layer 2 with black aluminum oxide. The laser-writable layer 2 has a top side 4 and a bottom side 5, which are arranged opposite one another and point away from one another. Viewed in a first direction 6, the top side 4 is arranged in front of the bottom side, or the first direction 6 points from the top side 4 to the bottom side 5.

Viewed in the first direction 6, a transparent protective layer 3 is arranged directly in front of the laser-writable layer 2 in order to protect the laser-writable layer 2 from external influences.

A contrast layer 7, eg white, is arranged behind the laser-writable layer 2 as seen in the first direction 6, whereby the contrast layer 7 does not have to immediately follow the laser-writable layer 2. If, as described at the beginning, the laser-writable layer 2 is written on with a laser, the laser-writable layer 2 becomes transparent along the path of the laser beam, whereby the contrast layer 7 makes the said path particularly clearly visible.

Typically, the contrast layer 7 can be applied with a self-adhesive layer 15 on a substrate 9, wherein the substrate 9 is formed, for example, by a product whose authenticity is to be guaranteed by means of the security label 1.

In order to ensure document authenticity, it is provided in the security label 1 according to the invention that at least one of the several layers is designed as a fracture layer 8 made of a brittle plastic film in order to cause destruction of the at least one fracture layer 8 and the laser-writable layer 2, and optionally one or more intermediate layers, in the event of manipulation or detachment of the security label 1 stuck to a substrate 9.

To ensure optimum brittleness, the brittle plastic film of the at least one fracture layer 8 can have an elongation at break of less than 20%, preferably less than 15%, particularly preferably less than 10%.

Fig. 1 shows a schematic sectional view of a first embodiment of the laser-writable security label 1 according to the invention. Viewed in the first direction 6, the following sequence of layers arranged one behind the other results: the protective layer 3 formed by a transparent PET film 13 (PET = polyethylene terephthalate); the laser-writable layer 2; a partial release lacquer layer 10, a laminating adhesive layer 11; the fracture layer 8, which is formed by a white acrylate film 16 and at the same time represents the contrast layer 7; the self-adhesive layer 15, with which the security label 1 is applied to the substrate 9.

If the security label 1 is manipulated or if an attempt is made to remove the security label 1 from the substrate 9, the fracture layer 8 breaks and destroys the arranged layers, i.e. those layers which are arranged in front of the fracture layer 8 as seen in the first direction 6, and thus in particular also the laser-writable layer 2.

The partial release lacquer layer 10 is not completely continuous, so that certain symbols or characters are also created when the security label 1 is removed in order to further increase the authenticity of the document. The partial release lacquer layer 10 provides a different adhesion between layers arranged in front of and behind the release lacquer layer 10 - i.e. in particular between the laser-writable layer 2 and the white acrylate film 16 or the laminating adhesive layer 11 - compared to the adhesion of these layers without an intermediate release lacquer layer 10, in order to cause a detachment of certain shaped areas when the security label 1 is removed or manipulated and to make the symbols mentioned visible. The partial release lacquer layer 10 can for this purpose in particular have the shape of one or more letters, one or more characters, one or more symbols, one or more lines, one or more guilloches, one or more numbers or one or more lettering.

Fig. 2 shows a second embodiment of the security label 1 according to the invention with a particularly compact structure that requires a minimum number of layers. Viewed in the first direction 6, the transparent protective layer 3 is again provided as the first layer, which in this case is formed by a transparent acrylate film 17 and thus also simultaneously forms the fracture layer 8. The laser-writable layer 2 is arranged directly behind the protective layer 3, so that if the fracture layer 8 is destroyed, the laser-writable layer 2 is also reliably destroyed.

The laser-writable layer 2 is in turn arranged directly on the contrast layer 7, wherein the contrast layer 7 is formed by a white lacquer layer 18. Behind the contrast layer 7 is arranged the self-adhesive layer 15, with which the security label 1 is applied or glued to the substrate 9.

Fig. 3 shows a third embodiment of the security label 1 according to the invention, wherein the fracture layer 8 is again formed by the contrast layer 7, in that the contrast layer 7 is formed as a white acrylate film 16.

In this embodiment, the transparent protective layer 3 comprises not only the transparent PET film 13, but also a transparent UV transfer lacquer layer 19, which represents a particularly favorable solution in terms of process technology for producing the at least one protective layer 3. The transparent PET film 13 arranged in the first direction 6 immediately in front of the UV transfer lacquer layer 19 is usually removed again before the security label 1 is applied to the substrate 9 (by peeling it off), which can happen in different process steps. Accordingly, in Fig. 3 the security label 1 is also not shown applied to the substrate 9.

Viewed in the first direction 6, the following sequence of layers arranged one behind the other results: the transparent PET film 13; the UV transfer varnish layer 19; the laser-writable layer 2; the (transparent) laminating adhesive layer 11; the white acrylate film 16; and the self-adhesive layer 15, with which the security label 1 can be applied to the substrate 9. If the fracture layer 8 is destroyed, all layers arranged above the fracture layer 8 - and thus in particular the laser-writable layer 2 - of the security label 1 applied to the substrate 9 are also reliably destroyed.

Fig. 4 shows a fourth embodiment of the security label 1 according to the invention, wherein the fracture layer 8 is again formed by the contrast layer 7 and a particularly compact structure can be achieved with a minimal number of layers. The transparent protective layer 3 is formed in this case by a protective lacquer layer 20, which not only protects the surface of the security label 1 from abrasion, but can in particular be matt in order to prevent reflections and thus facilitate the readability, in particular by machine, of the information (symbols, writing, etc.) encoded in the laser-writable layer 2. Seen in the first direction 6, the laser-writable layer 2 is arranged directly behind the protective lacquer layer 20 and directly behind this is the contrast layer 7 or fracture layer 8 formed by the white acrylate film 16. Accordingly, the laser-writable layer 2 is destroyed extremely reliably if the fracture layer 8 breaks or is destroyed. Behind the fracture layer 8 there is only the self-adhesive layer 15 with which the security label 1 is applied to the substrate 9.

Fig. 5 shows a fifth embodiment of the security label 1 according to the invention, in which two break layers 8 are provided in order to guarantee a particularly thorough destruction of the security label 1 in the event of manipulation or an attempt to pull it off. One of the two break layers 8 is formed by the transparent protective layer 3, which is designed as a transparent acrylate film 17. Viewed in the first direction 6, the laser-writable layer 2 is arranged directly behind the transparent acrylate film 17, which is accordingly destroyed in a highly reliable manner if the transparent acrylate film 17 breaks or is destroyed. The laser-writable layer 2 is arranged with a laminating adhesive layer 11 on the contrast layer 7, which is formed by a white acrylate film 16 and thus forming the second fracture layer 8. Immediately behind the contrast layer 7 is the self-adhesive layer 15, with which the security label 1 is applied to the substrate 9.

REFERENCE SYMBOL LIST

1

security label

2

laser-writable layer

3

protective layer

4

top of the laser-writable layer

5

underside of the laser-writable layer

6

First Direction

7

contrast layer

8

fracture layer

9

underground

10

Partial release coating

11

laminating adhesive layer

13

Transparent PET film

15

self-adhesive layer

16

White acrylic film

17

Transparent acrylic film

18

white lacquer layer

19

UV transfer varnish layer

20

protective varnish layer

Claims (8)

1. Security label (1), having a plurality of layers comprising

   - a laser-writable layer (2) with black aluminum oxide, wherein the laser-writable layer (2) has an upper side (4) and a lower side (5) which are arranged opposite one another and face away from one another,

   - at least one transparent protective layer (3), which is arranged in front of the laser-writable layer (2) as seen in a first direction (6), in order to protect the laser-writable layer (2) from external influences, wherein the first direction (6) faces from the top side (4) to the bottom side (5), and

   - a contrast layer (7), which is arranged behind the laser-writable layer (2) as seen in the first direction (6),

   wherein at least one of the plurality of layers is formed as a breakage layer (8) of a brittle plastic film in order to cause destruction of the at least one breakage layer (8) and of the laser-writable layer (2), and optionally of one or more interposed layers, in the event of manipulation or detachment of the security label (1) affixed to a substrate (9),

   and wherein the contrast layer (7) is designed as a breakage layer (8), characterized in that at least one further layer is arranged between the laser-writable layer (2) and the contrast layer (7), wherein the at least one further layer comprises at least one partial release lacquer layer (10), and in that the brittle plastic film of the at least one breakage layer (8) has an elongation at break of less than 20%, preferably less than 15%, particularly preferably less than 10%.
2. Security label according to claim 1, characterized in that the brittle plastic film of the at least one breakage layer (8) is an acrylate film or a polyvinyl chloride film or a polyurethane film.
3. Security label according to one of claims 1 to 2, characterized in that the at least one protective layer (3) comprises a layer of a UV transfer lacquer.
4. Security label according to one of claims 1 to 3, characterized in that the at least one protective layer (3) comprises a layer of a protective lacquer or printing lacquer.
5. Security label according to one of claims 1 to 4, characterized in that the at least one protective layer (3) comprises a layer of a plastic film, in particular polyethylene terephthalate film.
6. Security label according to one of claims 1 to 5, characterized in that at least one further layer is arranged between the protective layer (3) and the laser-writable layer (2), wherein the at least one further layer comprises at least one partial release lacquer layer (10).
7. Security label according to one of claims 1 to 6, characterized in that the at least one partial release lacquer layer (10) has the form of one or more letters, of one or more characters, of one or more symbols, of one or more lines, of one or more guilloches, of one or more numbers or of one or more lettering.
8. Security label according to one of claims 1 to 7, characterized in that the contrast layer (7) is arranged directly behind the laser-writable layer (2) as seen in the first direction (6).

Images