FILM STRUCTURE WITH TAMPER PROTECTION

Description

[0001] The following describes a foil structure with tamper protection based on a void effect.

[0002] For identification purposes, foil structures in the form of labels or plaques are typically affixed to the objects to be marked. To detect any tampering with a label or plaque, the foil structure can be tamper-evident. With a foil structure featuring a void effect, when the foil structure is removed from an object, part of the marking remains on the substrate, while another part adheres to the removed foil layer. Thus, the marking, and therefore the printed text, is destroyed.

[0003] The altered lettering should make the manipulation visually apparent. However, counterfeiters often manage to reattach the detached foil layer, along with the attached marking fragments, to the remaining layers on the substrate in such a way that the detached marking sections fit together very precisely with the remaining marking fragments. The manipulation of the foil structure is therefore not noticeable, at least at first glance.

[0004] US Patent 4,184,701 A describes a counterfeit-proof label. The label has a flexible, transparent backing layer on whose inner surface an information-carrying layer is printed. A rasterized layer, responsible for a void effect, is applied over the information-carrying layer and the unprinted areas of the transparent backing layer. A colored adhesive layer is applied to the underside of the label for adhesion to a substrate.

[0005] One objective of the present invention is to provide a film structure with tamper protection in which, when an attempt is made to remove the film structure from a substrate of a

[0006] When the object detaches, a void effect occurs, and the detached layers of the film structure cannot be rejoined with the layers of the film structure remaining on the substrate in such a way that the triggered void effect is no longer recognizable.

[0007] A film structure with tamper protection based on a void effect, in which the triggered void effect is still recognizable after an attempt to re-adhere the detached film layer to the layers of the film structure remaining on the substrate of an object, is specified in claim 1.

[0008] The tamper-evident film assembly comprises a void layer for triggering a void effect and a cover layer arranged above the void layer. The cover layer is, for example, formed by a film layer. The film assembly also includes a pattern layer for creating a pattern, with the pattern layer arranged below the void layer. The pattern layer is designed such that the pattern it contains has at least one rasterized area.

[0009] The pattern layer corresponds to a layer containing a grid, for example, in the form of spaced-apart dots, i.e., a dot pattern. In addition to the griddled area, another structure, such as a guilloche or other image motif, can also be integrated into the pattern layer.

[0010] At least one information layer can be arranged between the void layer and the pattern layer. This at least one information layer can include a layer that serves as an identifier, for example, a label in the form of letters or numbers, or an image.

[0011] The void layer has at least one first region containing a release agent and at least one second region lacking a release agent. The first and second regions are directly adjacent to each other. In the second region of the void layer, where no release agent is present, the cover layer adheres directly to the underlying layer, for example, the at least one information layer or directly to the pattern layer.

[0012] In the film structure, a background color layer can be arranged directly beneath the pattern layer. The background color layer can, for example, be a solid color layer, such as a white or gray layer. In particular, the background color layer can be applied across the entire surface. To adhere the film structure 1 to the substrate of an object, an adhesive layer is arranged beneath the background color layer. The background color layer can, in particular, be positioned between the pattern layer and the adhesive layer.

[0013] Due to the release agent partially present in the void layer, an attempt to peel off the film assembly adhered to an object's substrate triggers a void effect. In those areas of the film assembly where the void effect occurs, the top or backing film separates from one or more of the layers beneath it. Because of the void layer's segmentation, those parts of the information layers located beneath the void layer containing the release agent remain adhered to the underlying layers of the film assembly. That is, these parts of the information layers remain bonded to the substrate. Other parts of the information layers, not located beneath the void layer containing the release agent, remain adhered to the backing film and are lifted off along with it.

[0014] Due to the combination of the rasterized area of ​​the pattern layer and the underlying background layer, which acts as a background effect, the optical light trap is reduced in those areas of the film structure where the layers have separated from the release liner. As a result, when the release liner is re-adhered to the remaining part of the film structure, those areas of the release liner that were separated from the information layer during removal appear brighter than the areas that were not separated—that is, those areas of the release liner where parts of the information layer remained after removal. This significantly increases the optical detection of tampering. Therefore, with the same number of inks, improved optical detectability can be achieved in a printing press.

[0015] It should be noted that void effects in film structures can also be achieved with solid colors (transition to transparent). With solid colors, the contrast after triggering a void effect and attempting to rejoin the film layers is not immediately apparent, especially in glossy substrate films. This is because the glossy film and the affected area do not exhibit ideal contrast, as only a surface separation has occurred, and the triggering area itself has not been altered. For example, only the adhesive applied beneath the background layer contracts when the film is peeled from the substrate; the geometry of the remaining marking fragments on the substrate remains unchanged.

[0016] Another way to achieve a void effect in a film structure is to use a multi-color build. In a multi-color build, for example, the background appears in purple. When the film is removed from a substrate, hidden text in red is revealed, while the blue component of the original purple color remains on the substrate or disappears. A disadvantage of a multi-color build is that a mixed color is always created, which can exhibit visual variations. Furthermore, such a film structure requires a complex layered design. This layered design is often incompatible with existing machinery intended for its production.

[0017] In a commonly used film construction with a transparent void effect, a matte film is employed. When a label with such a film construction is separated from the substrate, the contrast is visually perceived as a more matte area at the point where the void layer had a release agent and an information layer stood out from the cover layer. This contrast occurs after the film layers are rejoined. A disadvantage of this method is that matte film cannot be used for many products requiring labeling, as it alters the perceived color, which is often undesirable for customers or applications.

[0018] According to the film structure according to the invention, there is no solid color layer below the void layer or below the at least one information layer. Instead, the pattern layer has at least one rasterized area. The rasterized area can be designed such that individual color dots are arranged at a specific dot spacing, with no color present between the color dots.

[0019] When an attempt is made to peel the adhesive foil structure from a substrate, part of the marking remains on the substrate in the areas where the void or release agent is present in the void layer. Transparent areas appear on the removed top layer / surface film in the areas where the void or release agent is present. If a counterfeiter attempts to re-adhere the removed top layer / surface film to the underlying layers, an optical shift occurs in the transparent areas of the top layer. This makes a motif / pattern clearly visible in the griddled area of ​​the pattern layer, which is embedded within the pattern layer.

[0020] The invention will be explained in more detail below with reference to figures showing exemplary embodiments of the present invention. These figures show: Figure 1a cross-section through a first embodiment of a film structure with tamper protection based on a void effect, Figure 2A an embodiment of a void-effect layer of a film structure with tamper protection, Figure 2B an embodiment of at least one information layer with a marking of a foil structure with tamper protection, Figure 2C an embodiment of a pattern layer and a background color layer of a film structure with tamper protection, Figure 3A a top view of a foil structure with tamper protection against triggering a void effect, Figure 3B A top view of a foil structure with tamper protection after triggering a void effect.

[0021] Figure 1Figure 1 shows a first embodiment of a film assembly 1 with tamper protection based on a void effect. The film assembly comprises a void layer 100 for triggering the void effect when an attempt is made to detach the adhered film assembly from a substrate of an object. The film assembly further comprises a cover layer 200, which is arranged above the void layer 100 in the film assembly. The cover layer 200 can, for example, be designed as a transparent film. In a top view, the cover layer 200 is configured as the uppermost layer or film layer in the film assembly.

[0022] For bonding the film assembly 1, the film assembly has an adhesive layer 300 on its underside. The adhesive layer 300 is located in the film assembly below, but not directly below, the void layer 100. The adhesive layer 300 can be applied from a Figure 1The protective film (liner) is not shown. Furthermore, the film structure 1 has a pattern layer 400 to form a pattern. The pattern layer 400 is located below the void layer 100 or between the void layer 100 and the adhesive layer 300.

[0023] The actual marking, which the foil structure 1 exhibits, is contained in at least one information layer 600a, ..., 600n. The at least one information layer 600 is present in the Figure 1 In the illustrated embodiment of the film structure, the information layer is arranged directly beneath the void layer 100. The at least one information layer 600a, ..., 600n is arranged between the void layer 100 and the pattern layer 400.

[0024] In at least one information layer 600a, ..., 600n, at least one color layer 610 is arranged such that a marking is created in the at least one information layer 600a, ..., 600n. The color layer 610 in the at least one information layer 600a, ..., 600n allows, for example, the implementation of a label in the form of numbers, letters, or other characters, or in the form of an image, within the film structure.

[0025] For the sake of simplicity, the color layer 610, for example a printing ink, is shown only in the information layer 600a. However, the marking in the film structure 1 can also be achieved by having further color layers 610 in the layers 600b, ..., 600n located below the information layer 600a, which together form the marking in the form of the lettering or image motif. Each of the information layers 600a, ..., 600n can be designed as a film layer onto which a color layer 610 is applied.

[0026] The pattern layer 400 is designed such that the pattern contained in the pattern layer 400 has at least one halftone area 410. This halftone area 410 of the pattern layer 400 can have a dot pattern in which dots are arranged at a specific interval. The dots can, for example, be arranged at a regular interval. When using an amplitude-modeled screen, the halftone dots always have the same center-to-center distance within a screen ruling. Instead, the size or shape of the halftone dots changes. In a 54 lpi screen, 54 dots per cm are arranged at a distance of 0.0185 cm (= 1 / 54 cm). The screen ruling ranges from 28 dots per cm in screen printing, corresponding to a distance of 0.0357 cm (= 1 / 28 cm), to 200 dots per cm in offset printing, corresponding to a distance of 0.005 cm (= 1 / 200 cm).Another possibility is to use a frequency-modeled grid, in which the grid points on a surface have the same point size but different spacing.

[0027] In addition to at least one halftone area 410, the pattern layer 400 can have at least one further area 420, in which, for example, a guilloche pattern is present. Unlike halftone area 410, the pattern contained in area 420 is realized by a printed solid surface. This does not consist of individual dots of a color that are unconnected to one another, but rather of interconnected dots of color that, for example, form individual lines of the guilloche. The pattern layer 400 can have a layer on which the halftone area 410 and, optionally, the guilloche 420 are applied, for example, by a printing process.

[0028] The film assembly 1 has a background color layer 500 below the pattern layer 400. The background color layer 500 is arranged between the pattern layer 400 and the adhesive layer 300. In the film assembly 1, the background color layer 500 is provided, in particular, directly below the pattern layer 400. The background color layer 500 can be designed as a solid color layer. The background color layer 500 can have a layer onto which the background color, for example, a white or gray color layer, is applied over the entire surface.

[0029] The void layer 100 has at least one first region 101 in which a void or release agent 110 is present. Furthermore, the void layer 100 has at least one second region 102 in which no void or release agent is present. The at least one first region 101 of the void layer 100 is directly adjacent to the at least one second region 102 of the void layer 100.

[0030] As demonstrated by Figure 1 As can be seen, the at least one rasterized area 410 of the pattern layer 400 is arranged in a vertical projection under at least one of the at least one first area 101 and under at least one of the at least one second area 102 of the void layer 100.

[0031] Figure 2A Figure 1 shows the void layer 100 with the release agent 110, which is arranged as a void motif in the void layer 100. In the illustrated embodiment of the Figure 2AThe release agent 110 is arranged in the void layer 100 in the form of interrupted circular segments (different radii).

[0032] Figure 2B Figure 600a, ..., 600n shows the at least one information layer. In the illustrated embodiment, the at least one information layer has several layers in which color layers 610 are arranged such that, for example, the coat of arms contained in the center of the at least one information layer or the edge lettering is formed as a marker of the film structure.

[0033] Figure 2CFigure 400 shows the pattern layer 400, located directly below the at least one information layer 600a, ..., 600n, with the rasterized area 410 and the guilloche-patterned area 420. Area 420 is designed as a solid color. The rasterized area 410 can, for example, contain colored dots forming a dot pattern. Alternatively, the rasterized area 410 can contain black or gray dots spaced apart from one another. Instead of a single-color dot pattern, a CMYK print in the pattern layer 400, combined with a white background in the background color layer 500, can be used, particularly in the case of a glossy film layer. The described embodiments of the rasterized area 410 are merely examples.

[0034] When attempting to peel off the film assembly 1 after it has been adhered to a substrate of an object, the sections 601 of the at least one information layer 600a, ..., 600n, which are arranged under the at least one first region 101 of the void layer, i.e., under the release agent 110, remain adhered to the substrate of the object when the film assembly is removed. The sections 602 of the at least one information layer 600a, ..., 600n, which are arranged under the second region 102 of the void layer 100, i.e., under the recessed area in which no release agent is present, remain adhered to the release film 200 when the film assembly is removed from the substrate of the object.

[0035] The Figures 3A and 3B Figure 1 shows a top view of the film structure. In the at least one information layer 600a, ..., 600n, the color layers 610 are arranged such that the in the Figures 3A and 3BThe marking shown, for example the coat of arms depicted on the left, is designed as a marking. The rasterized area 410 of pattern layer 400 is located beneath at least one information layer 600a, ..., 600n, that is, in the area of ​​the depicted cross of the foil structure. The area to the right of the cross contains a monochrome motif without a raster. The lines shown in this area are parts of a guilloche.

[0036] Figure 3A shows the structure of the film in its applied state before any manipulation. Figure 3B shows the foil structure after a manipulation attempt, where the previously lifted parts of the information layer, which remained stuck to the cover layer due to the void effect, are to be reattached to those parts of the information layer that remained stuck to the lower foil layers during the manipulation attempt.

[0037] Due to the combination of the rasterized area 410 of the pattern layer 400 and the underlying background color layer / effect area 500, an optical light trap is reduced when the foil structure is opened in the area of ​​the void effect. This causes the exposed areas—that is, areas of the cover layer where parts of the information layer adhered during removal—to appear brighter than the unexposed areas after reassembly. The void effect, here a circular arc, is visible in the cross-section. Figure 3B more clearly than in the adjacent monochrome gray area. The refraction of light makes the motif appear brighter. By deliberately placing a color-matched background layer 500 behind the raster surface 410, which acts as a contrasting surface, the optical perception of the triggered void effect is significantly enhanced. Reference symbol list

[0038] 1. Film structure 100. Void layer 110. Release varnish 200. Cover layer 300. Adhesive layer 400. Pattern layer 410. Rasterized area of ​​the pattern layer 420. Area of ​​the pattern layer without rasterization 500. Background color layer 600a, ..., 600n. Information layer 610. Color layer in the information layer

Claims

1. A foil structure including a tamper protection, comprising: - a void layer (100) for triggering a void effect, - a cover layer (200) arranged in the foil structure (1) over the void layer (100), wherein the void layer (100) comprises at least one first area (101) in which a release lacquer (110) is present and at least one second area (102) in which no release lacquer is present, wherein the at least one first area (101) of the void layer (100) directly adjoins the at least one second area (102) of the void layer (100), and wherein, due to the partially present release lacquer (110) in the void layer (100), the void effect occurs when an attempt is made to peel off the foil structure that has been glued to the substrate of an object, characterized in that the foil structure (1) has a pattern layer (400) for forming a pattern, which is arranged in the foil structure (1) under the void layer (100), the pattern layer (400) being designed in such a way that the pattern contained in the pattern layer (400) comprises at least one rasterized area (410), and wherein, due to the rasterized area (410) of the pattern layer (400), an optical light capture is reduced when the foil structure is opened in the area of the void effect.

2. The foil structure according to claim 1, comprising: a background color layer (500) arranged beneath the pattern layer (400).

3. The foil structure according to claim 2, wherein the background color layer (500) is formed as a full-surface color layer.

4. The foil structure according to claim 3, wherein the background color layer (500) is formed as a white color layer.

5. The foil structure according to any one of claims 1 to 4, wherein the at least one rasterized area (410) of the pattern layer (400) is arranged in a perpendicular projection under at least one of the at least one first area (101) and under at least one of the at least one second area (102) of the void layer (100).

6. The foil structure according to any one of claims 1 to 5, wherein the at least one rasterized area (410) of the pattern layer (400) has a dot pattern in which dots are arranged at a dot pitch.

7. The foil structure according to any one of claims 1 to 6, wherein the pattern layer (400) has, in addition to the at least one rasterized area (410), at least one further area (420) in which a guilloche is present as a pattern.

8. The foil structure according to any one of claims 1 to 7, comprising: - at least one information layer (600a, ... , 600n), in which a color layer (610) is arranged in such a way that a marking is formed in the at least one information layer (600a, ... , 600n), - the at least one information layer (600a, ... , 600n) being arranged between the void layer (100) and the pattern layer (400).

9. The foil structure according to claim 8, - wherein the void layer (100) is configured such that first sections (601) of the at least one information layer (600a, ... , 600n) of the foil structure (1), which are arranged under the at least one first area (101) of the void layer, remain adhered to the substrate of the object when the foil structure (1) is peeled off from the substrate of the object to which the foil structure (1) is glued by means of the adhesive layer (300), - wherein the void layer (100) is configured such that second sections (602) of the at least one information layer (600a, ... , 600n), which are arranged under the at least one second area (102) of the void layer (100), remain adhered to the cover foil (200) when the foil structure (1) is peeled off from the substrate of the object to which the foil structure (1) is glued by means of the adhesive layer (300).

10. The foil structure according to any one of claims 1 to 9, comprising: - an adhesive layer (300) for gluing the foil structure (1) to a substrate of an object, the adhesive layer (300) being arranged in the foil structure (1) under the void effect layer (100), - wherein the pattern layer (400) is arranged between the void effect layer (100) and the adhesive layer (300), - wherein the background color layer (500) is arranged between the pattern layer (400) and the adhesive layer (300).

11. The foil structure according to any one of claims 1 to 10, wherein the cover layer (200) is formed as a transparent foil.

12. The foil structure according to any one of claims 1 to 11, wherein the foil structure (1) is formed as a self- adhesive label or as a marking tag.