EP2168113B1 - Safety label - Google Patents

Abstract

The invention relates to a safety label allowing magnetic influences exerted thereon to be visualised by means of magnetic metal particles arranged within a multi-layer construction (12) and to a method of fabricating said safety label, a gel-like function layer (18) containing magnetically responsive metal particles incorporated therein being applied to the support layer (14), at least in specific zones, and surrounded by an adhesive layer (19) arranged on the support layer (14), the gel-like function layer (18) being covered by a covering layer (24) which is provided on a protective layer (28), such that the magnetically responsive metal particles may migrate from the function layer (18) to the covering layer (24) when exposed to a magnetic influence and the proportion of metal particles having passed into the covering layer (24) is visualable.

Description

The invention relates to a security label according to the preamble of claim 1.

From the WO 03/061960 A1 goes out a label for the visualization of magnetic influences or forces. This label comprises a layer structure having a first substrate layer deposited on a layer of magnetically sensitive microcapsules. The latter layer is provided with an opaque base layer, which can be attached to an object by an adhesive layer. The magnetosensitive microcapsules comprise a mixture of magnetic particles in a suspension layer. Such magnetic particles are formed of metal and have a first and second surface with different optical surface. When acting on a Magnetic field on this layer, the magnetic particles are aligned by rotation.

From the U.S. Patent 5,079,058 For example, there is a laminated layer structure in which a fluid layer is prepared by a process having on one side of the layer a powdery magnetic material for forming a fluid film and operating in response to the magnetic force. In this case, a pattern is to be generated by the magnetic elements in the fluid film, for example of plastic and a solvent, upon the action of the magnetic force.

Such devices have the disadvantage that they are expensive to manufacture. In addition, a clear representation of a force acting on the security label magnetic force is not possible.

From the DE 10 2006 010 382 B3 a security label is known for the visualization of magnetic influence acting thereon. Such a security label has a carrier layer and a semipermeable layer attached thereto, wherein the semipermeable layer is covered by a protective layer. Between the carrier layer and the semipermeable layer may be applied a slightly adherent adhesive layer to which the metal particles are applied. The semipermeable layer has flaps which, upon application of a magnetic force, open onto the security label toward the protective layer so that individual magnetically responsive metal particles can migrate through the semipermeable layer. After the action of the magnetic force, the flaps close automatically and in an indicator zone between the semipermeable layer and the transparent protective layer, the metal particles accumulate. Such security tags are easier to manufacture than prior art devices. However, the requirements for such security labels, also with regard to their clear representation of the applied magnetic force, is increasing steadily.

The invention is therefore an object of the invention to provide a security label, which includes a simple structure and a statement allows for the duration of a magnetic force on the security label.

This object is achieved by the features of claim 1 and claim 13. Further advantageous embodiments and further developments are specified in the respective dependent claims.

The inventive design of a security label for visualization of acting thereon magnetic influences with a on the support layer at least partially applied gel-functional layer are introduced in the metal particles and with a gel-like cover layer which covers the functional layer, wherein the magnetically responsive magnetically responsive metal particles of the functional layer migrate into the cover layer, it is possible that during a magnetic force over a shorter or longer period of time an emigration process of the metal particles from the functional layer and an immigration takes place in the cover layer and thus the immigrated metal particles are visible in the gel-like cover layer. In addition, this embodiment of the invention makes it possible that with a longer acting period of a magnetic force an increased storage of metal particles in the cover layer, so that by the increased incorporation of the metal particles in the cover an optical change, such as a gradually uniform coloring or clouding, which can be concluded by the degree of coloring or clouding on the duration of the action of a magnetic field. Such information is particularly advantageous when attached to electricity meters to show that it was not just a manipulation as such, but also how long the manipulation took place. Such manipulation consumes electricity without the meter registering this consumption.

According to a preferred embodiment of the invention, it is provided that the gel-like functional layer is solvent-free. This will achieves a non-drying functional layer and ensures the longevity of the security label. By this non-drying functional layer, the function of emigrating the metal particles from the functional layer is retained.

According to a further preferred embodiment of the invention it is provided that the gel-like functional layer is saturated with magnetically responsive metal particles. It is thereby achieved that a uniform distribution of the magnetic particles is given in the functional layer and, even after prolonged storage or attachment of such a security label to an article, a consistent indication of magnetic field influences is possible and can be displayed.

The cover layer of the security label is preferably formed solvent-free. Due to the solvent-free design, the longevity is achieved in analogy to the functional layer.

Furthermore, it is preferably provided that the covering layer is made larger in a plane direction of extension than the gel-like functional layer to be covered. This ensures that the metal particles contained in the functional layer do not shimmer through the visible surface and give the impression of being tampered with. Rather, the display area is preferably delimited by the covering layer, with the protective film preferably being made transparent at least in the region of the covering layer.

Furthermore, it is preferably provided that a photopolymerized layer is formed on the functional layer by irradiation, in particular UV irradiation. On the one hand, during the production of the security label, this photopolymerized layer or wafer-thin skin makes it possible for the gel-like functional layer to remain in its applied position and form. On the other hand, this photopolymerized layer or skin on the functional layer is decisive for the proportion of metal particles which migrate from the functional layer into the covering layer, and thus determines the coloring or Clouding of the cover layer as a function of the duration of action of a magnetic field with.

According to a further preferred embodiment of the invention, it is provided that a photopolymerized layer or skin can be produced on the cover layer by irradiation, in particular UV irradiation. The irradiation of the functional layer and / or the covering layer can be effected by a UV lamp, a laser irradiation or the like. The same applies to this photopolymerized layer or skin as to the functional layer.

Furthermore, it is preferably provided that, depending on the viscosity of the gel-like functional layer and / or the thickness of the photopolymerized layer on the functional layer, the rate of passage of the magnetic metal particles into the covering layer can be determined. For example, a low viscosity, the migration rate is lowered. The same applies to the formation of the photopolymerized layer with an increasing thickness. As a result, security labels can be made available, which detect, for example, a manipulation of more than 24 hours, more than a week or more than one month, since it is only after this period of time that migration takes place due to the viscosity of the gel-like functional layer and / or the thickness of the photopolymerized layer the metal particles and storage in the cover layer is done so that these embedded in the cover metal particles are visible. By means of these parameters, it is also possible to realize indicator zones on a security label which respond at different exposure times, the individual indicator zones comprising the functional layer, the cover layer and, if appropriate, photopolymerized layers provided thereon with different migration parameters.

Furthermore, it is preferably provided that a rate of migration of the magnetic metal particles into the covering layer is determined as a function of the viscosity of the covering layer and / or the thickness of the photopolymerized layer thereon. analog applies to the functional layer. Depending on the gel materials used, differently thick photopolymerized layers can be formed on the functional layer and the cover layer in order to achieve the corresponding migrations of the metal particles and derive therefrom the corresponding conclusions regarding the manipulations.

The covering layer is preferably provided with color pigments deviating from the metal particles. This can be a coloring or clouding, in particular a gray coloration of the cover layer in the use of white or light color pigments and dark metal particles, be given, wherein the degree of coloration represents the duration of the installation of a permanent magnetic field. The increasing gray coloration of the cover layer is based on the increasing number of metal particles, in particular ferrite powder particles, which migrate into the cover layer, so that a statement about the duration of the magnetic field effect can be read therefrom.

It is preferably provided that the cover layer is at least partially formed as a transparent film. As a result, a simple detection of any manipulations and a simultaneous protection of the cover layer is made possible. For ease of manufacture it can be provided that the carrier layer receives both the functional layer and the cover layer and is transparent, so that no separate protective layer is required.

The object underlying the invention is further solved by the features of claim 13. The inventive method for producing the security label a simple and inexpensive production is possible. In this case, it is provided that the gel-like functional layer applied to the carrier layer with metal particles incorporated therein and the covering layer to be assigned to the functional layer are applied in a mirror image along a straight line on the carrier layer, so that they can be folded along the mirror straight line after application, so that the covering layer of the functional layer is assigned and this covered. This allows a simple and safe handling of the gel-functional layer and covering layer are made possible, wherein the regionally applied layers can be maintained in shape. By folding the transport layer and the congruent superimposing of the at least one covering layer to the at least one functional layer, a cost-effective method is made possible, which in particular enables a continuous production of the security labels as web goods.

According to an advantageous development of the method, it is provided that the functional layer is photopolymerized with at least one irradiation source. This photopolymerization is preferably carried out before folding the carrier layer. This allows the gel-like functional layer with a thin, preferably wafer-thin,

Skin or layer to be completed upwards, this layer is also provided as a time indicator for the magnetic field influence.

According to a further advantageous embodiment of the method, it is provided that at least the functional layer, the covering layer or the adhesive layer is applied by a screen printing process. As a result, the individual layers can be applied simply and inexpensively by known screen printing techniques.

Furthermore, it is preferably provided that the functional layer is saturated with a proportion of at least 40% magnetically responsive metal particles. As a result, a uniform distribution of the metal particles in the functional layer is made possible, which counteracts unequal settling after prolonged use, without the influence of a magnetic field being present.

Furthermore, it is preferably provided that the covering layer is saturated with a color particle content of at least 40%. At the same time, the color particles are selected with a different color from the metal particles. As a result, a completely covering covering layer can be provided, which takes on a coloring depending on the degree of migration through the metal particles, which in turn represents a measure of the duration of the magnetic field influence.

Figur 1

eine schematische Seitenansicht der erfindungs- gemäßen Ausgestaltung eines Sicherheitseti- ketts,

Figur 2

eine schematische Ansicht auf das Sicherheits- etikett gemäß Figur 1 und

Figuren 3a bis c

schematisch dargestellte Schritte zur Herstellung eines Sicherheitsetiketts gemäß Figur 1.

The invention and further advantageous embodiments and developments thereof are described in more detail below with reference to the examples shown in the drawings and explained. The features to be taken from the description and the drawings can be applied individually according to the invention individually or in combination in any combination. Show it:

FIG. 1

1 is a schematic side view of the inventive design of a security label,

FIG. 2

a schematic view of the security label according to FIG. 1 and

FIGS. 3a to c

schematically illustrated steps for producing a security label according to FIG. 1 ,

In FIG. 1 is a schematically enlarged sectional view of a security label 11 for visualization of magnetic influences acting thereon. Such security labels 11 preferably have an areal extent of a few square millimeters to a few square centimeters. The security label 11 comprises a layer structure 12 with a carrier layer 14, which according to the exemplary embodiment is provided with a firmly adhering adhesive layer 16 and a protective film 17 arranged thereon for protection. Such an adhesive layer 16 and protective film 17 can be applied to both the bottom and the top of the security label 11 as needed. Such a protective film 17 is peeled off immediately before attaching the security label 11 at its destination, so that a self-adhesive security label 11 is formed and attachable to the destination.

The carrier layer 14 receives a gel-like functional layer 18, which extends at least partially along the carrier layer 14. This gel-like functional layer 18 is formed solvent-free. By way of example, the functional layer 18 is applied to the carrier layer 14 in the form of dots or drops. Similarly, the functional layer 18 seen in plan view can also be applied square or rectangular. Furthermore, patterns or graphic designs may be provided on the functional layer 18, which are preferably applied via a mask.

In the functional layer 18 magnetically responsive metal particles are incorporated, wherein a proportion of at least 60% metal particles is provided, so that the gel-like functional layer 18 is saturated. Between the functional layers 18 is preferably an adhesive layer 19, which limit the functional layer 18 in the direction of extent of the carrier layer 14.

Depending on the size and function of the security label 11, a functional layer 18 or a plurality of functional layers 18, which are arranged, for example, in a row, in a grid pattern or with further patterns, may be provided on the carrier layer 14. The attachment of several functional layers 18 may be provided to secure a larger area against impacts. Furthermore, the functional layers 18 may differ in their design and construction from one another in order to visualize different exposure times of magnetic field influences. In addition, individual functional layers can be constructed identically in order to enable redundancy and to check the detected manipulation of the redundant functional layers 18 for their correctness.

Opposite the carrier layer 14, the functional layer 18 has a photopolymerized layer 21, which is formed as a wafer-thin layer or as a wafer-thin pellicle. The functional layer 18 with the photopolymerized layer 21 is completely covered by a cover layer 24. The cover layer 24 is preferably made larger in its planar extension direction, ie in the extension direction along the XY plane, than the functional layer 18, so that complete coverage of the functional layer 18 is ensured. The cover layer 24 is preferably provided as a solvent-free gel, which may also be formed with a photopolymerized layer 26. The cover layer 24 is saturated with a color pigment which is deviating from the color of the metal particles. The cover layer 24 is supported by a protective film 28 which is transparent at least in the region of the cover layer 24. In a preferred embodiment, which will be described below, the protective film 28 corresponds to a part of the carrier layer 14. The cover layer 24 is also bounded by the adhesive layer 19 in a horizontal orientation or along the XY plane.

In FIG. 2 is a plan view of the security label 11 according to the invention FIG. 1 shown. Due to the at least partially transparent protective film 28, the cover layer 24 is visible. Because of the covering layer 24 saturated with color pigments, the respectively underlying functional layer 18 is not visible and only shown in dot-dash lines. As soon as an influence of a magnetic field acts on the security label 11, the magnetic particles begin to migrate beyond a specific magnetic force by migrating through the gel functional layer 18, through the photopolymerized layer 21 of the functional layer and optionally through the photopolymerized layer 26 into the cover layer 24 and store in the cover layer 24 or the migration is stopped by the adjacent to the cover layer 24 protective layer. A coloring of the cover layer 24 given thereby signals the presence of the magnetic field infusion with a minimum force as such and with increasing discoloration the duration of the action of the magnetic field. For example, as in FIG. 2 is shown, four indicators 29 may be provided consisting of the functional layer 18, the photopolymerized layer 21, optionally the photopolymerized layer 26 and the cover layer 24, wherein each of the indicators 29 a different viscosity of the functional layer 18 and cover layer 24 and a different layer thickness of the photopolymerized layer 21 and optionally the further photopolymerized layer 26 has. This makes it possible that a security label 11 is formed with, for example, a four-stage display, which shows depending on the exposure time gradually the action in the respective cover layer 24. Thus, for example, the indicator 29 'only indicates an incipient coloring after the indicator 29 has already taken a complete coloring. The same applies to the indicator 29 "and 29"'.

Alternatively it can be provided that the indicator 29 and 29 'are redundant, so that the security label 11 allows a test of the own display in the cover layer 24.

In the FIGS. 3a to c individual process steps for producing a security label 11 according to the invention are shown. On a carrier layer 14, which is at least partially preferably transparent, a functional layer 18, which is formed dot-shaped or drop-shaped applied. Before, simultaneously or afterwards, the covering layer 24 can be applied, which preferably takes place mirror-symmetrically along a straight line 31 and corresponds to a folding edge to be described later. The adhesive layer 19 can then be applied. Alternatively, it can also be provided that the adhesive layer 19 is applied first or after the application of the functional layer 18 and before the application of the covering layer 24. The application of these layers 18, 19 and 24 takes place in a screen printing process. In a subsequent step, a photopolymerized layer 21 and 26 is formed by a UV radiation source on the functional layer 18 and the cover layer 24, as shown FIG. 3 evident.

In the subsequent working step, the carrier layer 14 is folded along the straight line 31, which represents a folding edge, so that the covering layer 24 completely covers the functional layer 18. This is in Figure 3c shown. Following this, the edge regions are trimmed, if necessary, and the adhesive layer 16 is applied with a protective film 17 provided for protection on a top side or underside of the security label 11.

All the above-described features are considered individually in each case and essential to the invention in any desired combination.

Claims (15)

1. A safety label allowing magnetic influences exerted thereon to be visualised by means of magnetically responsive metal particles arranged in a multi-layer construction (12), with the multi-layer construction (12) comprising at least one support layer (14), with a function layer (18) comprising magnetically responsive metal particles applied at least in specific zones to the support layer (14) and the function layer (18) is covered by a covering layer (24), provided on a protective layer (28), characterized in that the function layer (18) is gel-like and incorporating magnetically responsive metal particles, that the function layer (18) is surrounded by an adhesive layer (19) arranged on the support layer (14) and the covering layer (29) is gel-like such that the magnetically responsive metal particles may migrate from the function layer (18) to the covering layer (24) when exposed to a magnetic influence and the proportion of metal particles having passed into the covering layer (24) is visualable.
2. The safety label as claimed in claim 1, characterised in that the gel-like function layer (18) is solvent-free.
3. The safety label as claimed in claim 1, characterised in that the gel-like function layer (18) is saturated with magnetically responsive metal particles.
4. The safety label as claimed in claim 1, characterised in that the covering layer (24) is realised in the form of a gel-like and preferably solvent-free layer.
5. The safety label as claimed in claim 1, characterised in that the covering layer (24), as considered in a planiform extension, is larger than the gel-like function layer (18) that is to be covered.
6. The safety label as claimed in claim 1, characterised in that on the gel-like function layer (18) and/or the covering layer (24) a photopolymerised layer is formed using irradiation.
7. The safety label as claimed in any of the preceding claims, characterised in that the transmigration speed of the magnetic metal particles into the covering layer (24) is determined as a function of the viscosity of the function layer (18) and/or the thickness of the polymerised layer (21) present on the function layer (18).
8. The safety label as claimed in any of the preceding claims, characterised in that the immigration of the magnetic metal particles into the covering layer (24) is determined as a function of the viscosity of the covering layer (24) and/or the thickness of the photopolymerised layer (26) of the covering layer (24).
9. The safety label as claimed in any of the preceding claims, characterised in that the covering layer (24) is provided with coloured pigments which are different from the metal particles and the protective film (28) is preferably realised as a transparent film, at least in the zone of the covering layer (24).
10. A method for fabricating a safety label (11) allowing magnetic influences exerted thereon to be visualised

    - in which a gel-like function layer (18) is applied to a support layer (14) and extends along the plane of the support layer (14), at least over specific zones,

    - in which a covering layer (24) is applied to a support layer (14) in a mirror-symmetric manner with respect to the at least one function element (18) and extends along the plane of the support layer (14), at least over specific zones, said covering layer being formed in a planiform extension with a size equal to, or larger than, the function layer (18),

    - in which an adhesive layer (19) is applied to the zones of the support layer (14) which are not covered by the function layer (18) and the covering layer (24), and

    - in which the support layer (14) is bent and folded up along a straight line of the mirror-inverted arrangement formed between the at least one function layer (18) and the at least one covering layer (24), such that the covering layer (24) covers the function layer (18).
11. The method as claimed in claim 10, characterised in that, in particular prior to the folding-up of the support layer (14), the gel-like function layer (18) is photopolymerised using an irradiation source, preferably a UV irradiation source.
12. The method as claimed in claim 10, characterised in that the covering layer (24) is photopolymerised using an irradiation source, preferably a UV irradiation source.
13. The method as claimed in claim 10, characterised in that at least one of the function layer (18), the covering layer (24) and the adhesive layer (19) is applied using a screen printing technique or an ink-jet printing technique.
14. The method as claimed in claim 10, characterised in that the gel-like function layer (18) is saturated to a proportional extent of at least 40 % with magnetically responsive metal particles.
15. The method as claimed in claim 10, characterised in that the covering layer (24) is saturated to an extent of at least 40 % with coloured particles which are of a different colour than the magnetically responsive metal particles.

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