EP2017809A2 - Adhesive security tape and method for its production - Google Patents

Abstract

The security adhesive strip useful as theft protection enveloping packaging strips e.g. transportation packing for cigarettes, comprises a first flexible carrier layer (2), a first adhesive layer (3) applied on one of the two surfaces of the first carrier layer, and a second flexible carrier layer (5) adhered on the free surface of the first carrier layer indirectly over a second adhesive layer (6). The first carrier layer is perforated along predetermined separating lines (4) in a partially completed manner. The separating lines are slots extending itself over the width of the safety tape. The security adhesive strip useful as theft protection enveloping packaging strips e.g. transportation packing for cigarettes, comprises a first flexible carrier layer (2), a first adhesive layer (3) applied on one of the two surfaces of the first carrier layer, and a second flexible carrier layer (5) adhered on the free surface of the first carrier layer indirectly over a second adhesive layer (6). The first carrier layer is perforated along predetermined separating lines (4) in a partially completed manner. The separating lines are slots extending itself over the width of the safety tape and separated through bars, and are sequence of perforations. The second flexible carrier layer is removed after cutting to size of the adhesive cover plate from the safety strip and specified gluing of the adhesive cover plate. The slots and/or perforations are produced by ablation using a working laser radiation. The material of the first carrier layer is absorbed for the working laser radiation and contains natural rubber content. The material of the second carrier layer is not absorbed for the working laser radiation. The second carrier layer is coated with a layer reflecting the working laser radiation, and consists of a tear-resistant material to remove the layer reliably in a unit after specified gluing of the adhesive cover plate. The separating lines represent an identifier by its line process. An independent claim is included for a procedure for the production of a security adhesive strip.

Description

The invention relates to a security adhesive tape, as it assembles to a security adhesive tab in the generic patent application DE 10 2007 016 483 is described. A generic method as claimed herein is also in the patent application DE 10 2007 016 483 explained.

An adhesive flap in the sense of the following description is intended to mean a usable piece of adhesive tape. It may have a predetermined or any length.

Basically, an adhesive tab serves to connect at least two end pieces of a flat material, e.g. B. of paper, cardboard or foil by the adhesive flap is glued covering each at least the impact or the overlap of the end pieces.

Adhesive flaps that can not be manipulated unnoticed, d. H. which are not reversibly removable and re-attachable, will be referred to below as a security adhesive flap. They are particularly suitable as anti-theft device for outer packaging (hereinafter also called packaging), in which a plurality of individual packaging are combined. Here, in particular, transport packaging for cigarette rods, smaller electronic devices and pharmaceutical products may be mentioned.

Adhesive tapes, from which such safety adhesive tabs are obtained by merely cutting to length, should be referred to as safety adhesive tapes.

In order to effectively form a tamper evident closure for packaging, particularly paper or paperboard, the security adhesive tab must be adhered to at least two butt or overlapping packaging parts such that removal of at least one of the packaging parts is required to open the package ,

From the prior art, a variety of self-adhesive tabs (also called adhesive tapes here) or adhesive labels, which are primarily used as labels for marking purposes, known that due to their special layer structure in a manipulation, d. H. Trying to remove them from the packaging will result in visible irreversible changes. Such custom-made adhesive tapes and adhesive labels are not readily available commercially, so they can not be replaced unnoticed.

The JP-A-09-176990 discloses, for example, an adhesive tape which consists of a pigment-containing layer with an adhesive portion and a protective layer above it. When removing the adhesive tape, the protective layer is completely removed, but the adhesive layer remains partially on the protective layer and partially stick to the packaging, ie the pigment-containing layer is visibly damaged and re-sticking is subsequently clearly visible. The disadvantage here is in particular the need for special adhesives, which must be introduced into the pigment-containing layer.

In the DE 299 13 746 U1 A layer construction for an adhesive label is described, consisting of a weakened lines intermediate layer of an adhesive layer and a continuous top film, which is applied by means of adhesive on the line provided with weakening lines. The top film has the function of providing a smooth and well printable surface to create a print image unimpaired by the lines of weakness.

Advantageously, the top film should be designed as a label carrier made of an easily destructible material to complicate a non-destructive peeling. A disadvantage of the adhesive label described here is the need for two different processing methods for introducing the lines of weakness, z. B. by punching and applying the label by printing.

In the DE 103 46 683 A1 an adhesive label is described, consisting of an adhesive layer and a film degradation with at least one layer which is injured by means of a laser beam, but not cut through. As suitable for this is called a polyester film, which has a sufficient tensile strength and heat stability to keep the film structure stable.
The material of the film layer adjoining the adhesive layer and the adhesive are selected so that a repositionability of the adhesive label is preferably still possible for about half an hour. The degree of weakness of the line of weakness, ie in particular the removal depth is material dependent and thickness-dependent chosen so that the adhesive label can be donated without destruction risk on the object to be adhered, a repositioning without damaging the adhesive label is guaranteed and after complete development of the adhesive layer, the adhesive label in the region of the line of weakness uncontrollably ruptures when attempting to remove the adhesive label.
In a preferred embodiment of the film structure, a laser-sensitive layer should be provided in addition to the weakened by laser radiation film layer. This can advantageously be introduced into the weakenable film layer, a line of weakness as well as a label in the laser-sensitive layer in one operation.
An adhesive label after the DE 103 46 683 A1 , which is to serve both for identification and as security closure, must, as explained, have a special film structure of at least two layers or in the case of only one layer, a marking can only be done by the additional step of printing.

All the aforementioned adhesive tabs and adhesive labels have in common that they are designed so that they undergo irreversible changes in the attempt of detachment, so that the same adhesive tab or the same adhesive label are not suitable for unnoticed reclosing and a same adhesive tab or a same adhesive label Replacement due to the special layer structure are not readily accessible.

In the DE 10 2007 016 483 are described a security adhesive flap and a method for their preparation, which can be produced by cutting to length of a commercially available, self-adhesive packaging tape and then in only be changed so that they are not destructively removable and moreover, if necessary, a marking carrier represent. For this purpose, the security adhesive flap is adhered as intended to an object (adhesive surface), that is, the security adhesive flap, as already described in the introduction, at least two ends of the packaging is glued overlapping. After sticking, laser radiation is directed to the surface of the security adhesive tab and guided along predetermined dividing lines so that the carrier material is removed along the dividing lines. The dividing lines can completely separate the safety flap into individual parts or even partially separate only the carrier material. In both cases, unnoticeable removal and reapplication of the safety adhesive flap is excluded. Advantageously, the line profile of the dividing line is selected such that it represents a marking. This can z. As a bar code or a lettering.

A disadvantage of this solution is, in particular, that the handling of a laser tool required for carrying out the method must be individually matched to the object intended for bonding and the adhesive position, and a corresponding laser tool must be at hand when closing the package.

The invention has for its object to provide a security tape and a method for its production, are produced from the adhesive tabs, which have the carrier material at least partially completely breaking dividing lines and can be cut to length from the security tape thus prefabricated.

This object is achieved for a security adhesive tape having the features of claim 1 and for a method for producing a security adhesive tape having the features of claim 10.

Advantageous developments are described in the subclaims.

Reference to the drawing, a security tape according to the invention is explained in more detail below by way of example.

Fig. 1

ein Schnittbild durch ein Sicherheitsklebeband,

Fig. 2a - 2d

Ausführungsformen von Klebebändern mit unterschiedlichem Trennlinienverlauf

Show it:

Fig. 1

a sectional view through a security tape,

Fig. 2a - 2d

Embodiments of adhesive tapes with different separation line course

Basically, a security adhesive tape 1 consists of a first carrier layer 2, a first adhesive layer 3, a second carrier layer 5 and a second adhesive layer 6, wherein the first adhesive layer 3 and the first carrier layer 2 are at least partially completely broken along dividing lines 4.

A security adhesive tape 1, produced by a method according to the invention, is to be described below as a particularly advantageous embodiment.

The choice of materials suitable for the adhesive layers 3, 6 and carrier layers 2, 5 is essentially determined by their function.

Thus, the first carrier layer 2 has the function of adhering permanently after sticking a cut to length from the security tape 1 piece of adhesive flap on an adhesive surface. It should not be possible to remove this first carrier layer 2 unchanged from the adhesive surface or to stick it back in unchanged form. For this purpose, the first carrier layer 2 should have separating lines 4 which partially or completely separate the material of the first carrier layer 2.

Only partially separating dividing lines, z. B. consisting of webs separated perforations or slits, cause the attempt to detach from the adhesive surface either that the dividing lines tear 4 or the webs be overstretched. Both lead to damage and perceptible change.

Completely separating dividing lines, d. H. Although cuts that extend over the entire width of the security adhesive tape 1, allow a non-destructive peeling, but the separated by the dividing lines 4 items can not be glued in place again identical in precision, which also a change is perceptible.

The course of the line can be selected specifically to form an identification.
The dividing lines 4 are therefore not only relevant for safety feature but also relevant for the marking.

In the Fig. 2a - 2d Examples of special lines are shown. For processing by means of laser, examples 2a, 2c and 2d are particularly suitable. They show dividing lines 4 of constant width. In Fig. 2a the dividing lines 4 are zig-zag lines that completely cut through the first carrier material across the width of the security adhesive tape 1.
In Figure 2c are dividing lines 4, consisting of several perforations and slots represented. The fewer webs connect the two adjacent parts, the greater the probability of destroying them.
This in Fig. 2d Pictured example is interesting in that stick here within the security tape 1 items that, the smaller they are executed, impossible to remove mechanically nondestructive.
This in Fig. 2b shown example differs from the other examples in that here the dividing lines 4, which represent a bar code, have different widths. This is achieved by forming several dividing lines 4 next to each other without gaps.
The second carrier layer 5 serves as a support layer, so that the first carrier layer 2 is securely held together during the introduction of the parting lines 4 and divided by the parting lines 4 or separated parts of the first carrier layer 2 in their Relative position remain unchanged. It remains even after the introduction of the dividing lines 4 adhering to the first carrier layer 2 to the first carrier layer 2 mechanically during the entire handling, for. B. to protect during transport and storage.
The security tape 1 is stored as conventional tapes as endless tape wound on rolls.
For gluing it can either be unwound directly from the roll on the intended adhesive surface and finally cut to length, or it is only a piece of a predetermined length deflected and then glued. As already explained, a usable piece of the security adhesive tape 1 should be understood as a security adhesive flap.

When sticking, the first carrier layer 2 with the adhesive layer receives a new support layer and the second carrier layer 5 loses its function.
If the dividing lines 4 in the first carrier layer 2 also have a characteristic function, the second carrier layer 5 is now necessarily removed. It is important that in this case the first carrier layer 2 is not damaged.

Functionally suitable for the first carrier layer 2 all flexible materials are suitable, which are machinable by laser, ie materials that absorb laser radiation.
Advantageously, they have only a low tensile strength, so that regardless of the material weakening along predetermined separation lines, a non-destructive solubility is made difficult by an adhesive surface.
An advantageously high irreversible extensibility of the material results in overstretching in the attempt to remove and thus prevents unnoticed re-sticking.
Suitable materials for the first carrier layer 2 are PVC, PP or polyester, but also paper in question, which advantageously have a natural rubber content.

For the second carrier layer 5 a tear resistant, flexible material is selected. Fabric, plastic and paper come z. B. here in question.

The material should advantageously also not be stretchable, in order to prevent the first carrier layer 2 from being stretched and thus changed when it is glued on.

This material is advantageously non-absorbent for the treatment laser radiation, or coated with a layer reflecting the processing laser radiation, in order to preclude a weakening of the second carrier layer 5 by the processing laser radiation.

For the first adhesive layer 3, depending on the material and the roughness of the surface (adhesive surface), which is intended to be adhered, an adhesive is selected which strongly adheres to this adhesive surface to the first carrier layer 2 indirectly via the first adhesive layer 3 with high adhesion to keep.

On the other hand, an adhesive is used for the second adhesive layer 6, which allows easy release of the second carrier layer 5 and damage to the first carrier layer 2 is reliably avoided.
The adhesion between the two carrier layers 2, 5 indirectly via the second adhesive layer 6 must therefore be appreciably lower than the adhesion between the first carrier layer 2 and the adhesive layer indirectly above the first adhesive layer 3.

As adhesive layers, e.g. Acrylate to be used.

A security adhesive tape 1 according to the invention is advantageously produced by a process according to the invention. Instead of using a laser, however, the separating cuts can also be introduced using other removing or separating methods, such as mechanical needling or cutting.

To carry out a method according to the invention, the multilayer material structure consisting of the two carrier layers 2 and 5 and the two is first prepared by conventional methods for producing conventional adhesive tapes Adhesive layers 4 and 6 prepared, the multilayer structure made up to a predetermined width for the security tape and wound on rolls. For introducing the parting lines 4, the security adhesive tape is unwound from a roll, guided over a laser processing area and wound up on another roll. While the security adhesive tape 1 is pulled over the laser processing area, laser radiation from the first adhesive layer 3 is directed onto the security adhesive tape 1. The necessary relative movement between the security adhesive tape 1 and the laser radiation for producing dividing lines 4 of predetermined line courses is advantageously a composite movement, determined by the direction of movement and speed of the adhesive tape on the one hand and the direction of movement and speed of the laser radiation on the other hand.
The process parameters of a laser delivering the laser radiation will be adjusted so that the first adhesive layer 3 and the first carrier layer 2 are completely penetrated by a single traverse of the parting lines 4. Advantageously, a continuously emitting or pulsed CO ₂ laser can be used.
It is clear to the person skilled in the art that the dividing lines 4 can also be generated by a plurality of lasers.

LIST OF REFERENCE NUMBERS

1

security tape

2

first carrier layer

3

first adhesive layer

4

dividing lines

5

second carrier layer

6

second adhesive layer

Claims (11)

Security adhesive tape (1) having a flexible first carrier layer (2) and a first adhesive layer (3) applied to one of the two surfaces of the first carrier layer (2), wherein the first carrier layer (2) is at least partially completely perforated along predetermined separation lines (4) , characterized
that on the free surface of the first carrier layer (2) indirectly via a second adhesive layer (6) a second flexible carrier layer (5) adheres, which is provided after the cutting to length of a security adhesive tab from the security adhesive tape (1) and a proper sticking the security adhesive tab removed to become. Security adhesive tape (1) according to claim 1, characterized
that the dividing lines (4) extends over the width of the adhesive security tape (1) are extending slots. Security adhesive tape (1) according to claim 1, characterized
in that the dividing lines (4) are rows of slots separated by webs. Security adhesive tape (1) according to claim 1, characterized
that the dividing lines (4) are juxtapositions of perforations. Security adhesive tape (1) according to any one of claims 2-4, characterized in that the slots or perforations are produced by removal by means of a processing laser radiation, and that the material of the first carrier layer (2) for the processing laser radiation is absorbent. Security adhesive tape (1) according to claim 5, characterized in that
that the material of the first support layer (2) contains a natural rubber component. Security adhesive tape (1) according to claim 5 or 6, characterized
in that the material of the second carrier layer (5) for the treatment laser radiation is non-absorbent. Security adhesive tape (1) according to claim 5 or 6, characterized
in that the second carrier layer (5) is coated by the second adhesive layer (6) with a layer which reflects the treatment laser radiation. Security adhesive tape (1) according to one of the preceding claims, characterized
that the second support layer (5) consists of a tear-resistant material, in order to remove this securely in one piece to the intended gluing a pre-cut adhesive safety strap therefrom. Security adhesive tape (1) according to claim 1, characterized
that the dividing lines (4) represent a marking by their line course. Method for producing a security adhesive tape (1). in which a first adhesive layer (3) is applied to a flexible first carrier layer (2) which is absorbent for processing laser radiation, characterized
that a second flexible support layer (5) indirectly via a second adhesive layer (6) with the free surface of the first support layer (2) is connected and the machining laser radiation onto the first adhesive layer (3) directed along predetermined dividing lines (4) (relative to the adhesive security tape 1 ), so that the processing laser radiation in the first carrier layer (2) along the parting lines (4) at least partially causes a complete removal of material.

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