DE202012011619U1 - security label - Google Patents

Abstract

Security label comprising a carrier (1) and at least one thermochromic security feature (4), and an adhesive layer, characterized in that the thermochromic security feature (4) comprises a full-surface thermochrome layer (2) and an optical security feature layer (3) applied to the thermochrome layer (2) includes.

Description

The invention relates to a security label with at least one thermochromic security feature.

Security labels are known in the art.

The DE 102 08 427 A1 relates to an adhesive seal, which has two mutually imperceptible or weakly connected sealing parts, both of which are arranged on a carrier, wherein the carrier is removed after the attachment of the adhesive seal and the sealing parts maintain their relative position to each other. After removing one of the sealed parts, the relative position can not be restored later.

The GB 2 270 857 A concerns a seal label with a temperature-sensitive area, which permanently changes its appearance when heated.

The DE 298 05 635 U1 relates to a security tag with a subsequently changed by thermal influence security feature.

Security labels may have proof of opening. The proof of opening can be based on making the opening of the security label visually recognizable. Even if you attempt to close the label after opening the label, you will see that the security label has already been opened. The principle of this type of opening detection can be based on the fact that partial areas of different adhesive strength are formed along the area over which the opening detection extends. When a carrier layer is removed, a lacquer layer is thereby broken perpendicular to the label plane. A color layer that becomes visible in some areas serves as a recognizable proof of opening. When re-laying the carrier layer form air pockets. The air inclusions produce a region-wise different refractive index, so that the opening detection remains recognizable.

One means to circumvent this opening detection is to reduce the bond strength of the adhesive layer with which the label is glued to the substrate, so that the security label can be detached without breaking the paint layer and the opening detection is not even triggered. Usually, the bond strength of standard adhesives is significantly reduced at temperatures of 60 ° C to 80 ° C. Such temperatures can be easily achieved by means of a commercial hair dryer. A known solution to detect the heating of the security labels is the use of temperature-sensitive security features, which are additionally applied to the security label. Temperature-sensitive security features may include irreversible thermochromic pigments, which preferably also change their color in the range of about 60 ° C to 80 ° C and do not undo their changed color on cooling.

A disadvantage of said security labels is that the thermochromic security features do not carry individualized information.

It is an object of the present invention to provide a security label which avoids the above-mentioned disadvantage.

The object is achieved by a security label having the features of claim 1.

The irreversible thermochromic pigments used in thermochromic security features are printed on the security labels in conventional printing processes, such as flexo or screen printing processes. However, such printing methods only allow a continuously identical pressure. Although this is economical, it is not suitable for applying individualized information. The known thermochromic security features are therefore identical for different security labels and do not contain individualized information.

The invention makes use of the idea to form a thermochromic security feature applied to a carrier according to the invention with a thermochromic layer formed over the entire area and an individual optical security feature layer applied to the thermochrome layer. Thermochrome layer and the optical security feature layer are arranged one above the other perpendicular to the security feature plane. By arranging the thermochrome layer and the security feature layer one above the other, the proof of tampering can be combined with individualized information.

A full-surface thermochromic layer is understood here to mean that the thermochromic layer has the entire surface in terms of the extent of the thermochromic security feature. The thermochrome layer by no means needs to cover the entire security label over the entire surface. The carrier is conveniently designed as a carrier film. Carrier films are flexible and inexpensive.

The security label comprises an adhesive layer with which it can be bonded to the surface to be sealed.

Between the carrier and the adhesive layer, further optical security features with opening detection are preferably provided. The thermochromic security feature according to the invention is advantageously arranged on the side of the carrier opposite the adhesive layer. Thus, manipulation attempts by heating the security label for the viewer from the outside are easy to recognize. However, the thermochrome layer can also be arranged between the adhesive layer and the carrier. Then she is better protected.

In a preferred embodiment of the invention, pigments of the thermochrome layer are chosen such that a contrast between the thermochromic layer and the optical security feature layer changes from a temperature at which the bond strength of the adhesive layer decreases, preferably decreases significantly. Usually, the adhesive strength of the adhesive layer remains high at temperatures up to approximately between 60 ° C to 80 ° C, depending on the selected adhesive, and then decreases significantly. Temperatures at which the bond strength is high, ie temperatures up to between 60 ° C to 80 ° C are referred to here as the normal temperature. By heating is meant here a temperature increase to above the normal temperature, ie above 60 ° C to 80 ° C.

In one embodiment of the invention, the contrast between the security feature layer and the thermochrome layer at normal temperature is recognizable to the human eye, preferably a scanner. After heating, the security feature layer preferably does not form a detectable contrast on the thermochrome layer. While the individualized information of the security feature is recognizable at normal temperature, it is no longer recognizable after heating in this embodiment of the invention.

Preferably, the contrast change is represented by color change. The optical security feature layer preferably has a security feature layer color identical throughout the security feature and the thermochrome layer has a thermochromic layer color identical to the thermochrome layer at normal temperature throughout the thermochromic layer, and even after the heating, the security feature layer color and thermochromic layer color are the same along the security feature, though possibly different from the color at normal temperature. Conveniently, the color of the thermochrome layer changes by heating to approximate the color of the heated optical security feature layer and the colors to the human eye, preferably a scanner, are indistinguishable. They are preferably identical.

In another embodiment of the invention, the optical security feature layer does not form a detectable contrast on the thermochrome layer at the above-mentioned normal temperature. Preferably, however, in this embodiment, the contrast changes by heating such that the heated security feature layer forms a detectable contrast on the heated thermochrome layer. Thus, the individualized information of the security feature is recognizable only when heated.

Preferably, the color of the thermochromic layer changes by heating such that it further differs from the color of the heated optical security feature layer and the colors to the human eye, preferably a scanner, form a recognizable contrast upon heating.

Under a recognizable contrast here is a recognizable to the human eye contrast or recognizable for a scanner contrast understood. The apparent contrast is sufficiently strong and large enough to fully recognize the individualized information of the security feature.

The thermochrome layer can be reversible, but it can also be irreversible. In reversible Thermochromschicht the thermochromic layer assumes its original state, preferably color after heating and cooling to room temperature again, while an irreversible Thermochromschicht their changed by the heating state, preferably color even after cooling, or at least a significantly different color than their original color maintains.

In a particularly inexpensive embodiment of the security label according to the invention, the thermochrome layer is applied directly to the carrier film and / or the optical security feature layer is applied directly to the thermochrome layer.

The thermochrome layer is preferably printed on the carrier film in flexographic or screen printing processes, the classical printing process, while the security feature layer is preferably printed individually on the already applied thermochrome layer in digital printing processes, such as inkjet processes, for each security label.

The optical security feature layer may include individualized information, preferably in the form of a QR code, data matrix code or a number code.

The thermochromic security feature can complete individualized information. The thermochromic security feature may contain information about the condition of the goods such as A and B goods.

The invention will be described with reference to an embodiment in two figures. Showing:

1 a schematic plan view of a security label according to the invention before heating,

2 a schematic plan view of the security label according to the invention in 1 after heating.

The security label according to the invention 10 has a carrier film 1 on. The carrier foil 1 preferably consists entirely of biaxially oriented polypropylene (BOPP), but other plastics are also conceivable.

The illustrated security label 10 includes one on one in 1 upwardly facing outside of the carrier film 1 applied thermochromic security feature 4 , On the in 1 downwardly facing inside of the carrier film 1 For example, a further optical security feature (not shown) with an opening detection can be applied. The security label 10 is with a (not shown) adhesive layer on the inside of the carrier film 1 is applied, aufklebbar on a surface to be sealed.

On one area of the carrier foil 1 is a thermochromic layer 2 applied. The thermochromic layer 2 is here directly on the carrier film 1 printed. The thermochromic layer 2 has temperature sensitive pigments. In the exemplary embodiment, the pigments are irreversibly formed and thus form an irreversible thermochromic layer 2 out. Upon heating, the irreversible pigments are chemically altered to alter their perceivable color to the human eye. However, after subsequent cooling, the pigments retain their changed state as a result of the heating and thus also the color change obtained by the heating.

Usually, the security labels 10 manufactured as a security label web. In this case, the individual security labels are along a carrier film web 10 printed side by side, and finally from the security label web the individual security labels 10 punched out.

Color pigments are usually very long, voluminous molecules that clog the nozzles of inkjet printers that have a very small diameter. In addition, thermal transfer processes are not suitable for the application of temperature-sensitive color pigments. Therefore, the thermochromic layer becomes 2 in classical printing processes such as flexo or screen printing on a web of a carrier film 1 printed.

In flexographic printing process, a printing plate mounted on a printing roller is inked by means of an anilox roller. The pressure roller contacts an impression cylinder which guides the carrier film web and onto which the thermochromic layer 2 partially or completely printed on. In screen printing process, however, a template is first applied to a stretched in a frame, fine tissue, the pigments are pressed through the fine tissue on the carrier film web. The areas covered by the stencil remain recessed.

The thermochromic layer 2 can be applied in an identical manner to predetermined areas of a plurality of security labels along the carrier film web by flexo and screen printing methods by separating them in a targeted and register-accurate manner in each of the security label areas along the carrier film web or printing them over the carrier film web over the entire area. Thus, the classical printing process is an intermediate product for producing the security label 10 In a first step, inexpensive and quickly produced.

After printing the thermochromic layer 2 is on the thermochromic layer 2 an individual optical security feature layer, in 1 in the form of a data matrix code 3 , applied by digital printing method, such as thermal transfer or inkjet printing method. The digital printing methods are computer-controlled, so that in an easy-to-handle way individual data matrix codes 3 , For example, read from a database and by means of the printer individually on the thermochromic layer 2 each of the security labels 10 can be printed.

1 shows a ready-made security label 10 with a data matrix code visible to the human eye at normal room temperature 3 on the different colored thermochromic layer 2 is printed. The data matrix code 3 is therefore readable, the data matrix code 3 can be scanned and decrypted using a Data Matrix Code Reader. For example, when trying to open a package with criminal energy, by the security label 10 is heated to bypass an opening effect (not shown) takes the thermochromic layer 2 the color of the data matrix code 3 at. The heated state is in 2 shown. The data matrix code 3 becomes unreadable. Also after cooling the security label 10 stay in 2 state shown received. The thermochromic layer 2 is irreversibly discolored.

The security label 10 thus indicates on the one hand the manipulation attempt, on the other hand, it has another function by the individualized data matrix code 3 becomes unreadable.

In areas of the security label 10 that from the thermochromic layer 2 are not covered, are usually the known security features 4 , as the opening checks described above, arranged. These are the ones in the 1 . 2 left, free areas of the security label 10 ,

LIST OF REFERENCE NUMBERS

1

support film

2

thermochromic layer

3

Data Matrix Code

4

safety feature

10

security label

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 10208427 A1 [0003]
• GB 2270857 A [0004]
• DE 29805635 U1 [0005]

Claims (19)

Security label with a carrier ( 1 ) and at least one thermochromic security feature ( 4 ), and an adhesive layer, characterized in that the thermochromic security feature ( 4 ) a full-surface thermochrome layer ( 2 ) and one on the thermochrome layer ( 2 ) applied optical security feature layer ( 3 ). Security label according to claim 1, characterized in that a contrast between the thermochrome layer ( 2 ) and optical security feature layer ( 3 ) changes from a temperature at which an adhesive strength of the adhesive layer decreases. Security tag according to one of claims 1 or 2, characterized in that the optical security feature layer ( 3 ) at normal temperature a noticeable contrast on the thermochrome layer ( 2 ) trains. Security tag according to one of claims 1, 2 or 3, characterized in that the optical security feature layer ( 3 ) a security feature color and the thermochrome layer ( 2 ) has a thermochromic layer color and the security feature layer color and the thermochromic layer color are recognizably different. Security tag according to one of claims 1 or 2, characterized in that the heated optical security feature layer ( 3 ) on the heated thermochrome layer ( 2 ) forms no recognizable contrast. A security tag according to claim 5, characterized in that a color of the heated thermochrome layer ( 2 ) and a color of the heated optical security feature layer ( 3 ) are the same. Security tag according to one of claims 1 or 2, characterized in that the optical security feature layer ( 3 ) at normal temperature no apparent contrast on the thermochrome layer ( 2 ) trains. Security tag according to claim 7, characterized in that the optical security feature layer ( 3 ) a security feature layer ink and the thermochrome layer ( 2 ) has a thermochromic layer color and the security feature layer color is not recognizable on the thermochromic layer color. Security tag according to one of claims 7 or 8, characterized in that the heated security feature layer ( 3 ) a noticeable contrast on the heated thermochrome layer ( 2 ) trains. A security tag according to claim 9, characterized in that a color of the heated thermochrome layer ( 2 ) and a color of the heated optical security feature layer ( 3 ) are recognizably different. Security feature according to at least one of the preceding claims, characterized in that the heated thermochrome layer ( 2 ) and the heated optical security feature layer ( 3 ) have a temperature of at least 60 ° C-80 ° C. Security feature according to at least one of the preceding claims, characterized in that the normal temperature is a temperature of up to 60 ° C-80 ° C. Security label according to at least one of the preceding claims, characterized in that the contrast is recognizable or not recognizable to the human eye. Security label according to at least one of the preceding claims, characterized in that the thermochrome layer ( 2 ) is reversible. Security label according to at least one of the preceding claims, characterized in that the thermochrome layer ( 2 ) is irreversibly formed. Security label according to at least one of the preceding claims, characterized in that the thermochrome layer ( 2 ) directly onto the carrier film ( 1 ) is applied. Security tag according to at least one of the preceding claims, characterized in that the optical security feature layer ( 3 ) directly onto the thermochrome layer ( 2 ) is applied. Security tag according to at least one of the preceding claims, characterized in that the heated thermochromic security feature ( 4 ) completes individualized information. Security tag according to at least one of the preceding claims, characterized in that the thermochromic security feature ( 4 ) Contains information about the condition of a sealed product.

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