EP1050485A1 - Tear strip with security feature, production method and its use in packaging material - Google Patents

Abstract

The pull-open strip with security marking, consisting of a thermoplastic carrier foil covered on one side with a sealing lay and on the other side possibly with a release layer, is characterized by the fact that the carrier foil is printed on one side w a security dye. An Independent claim is also included for a method which involves steps of printing with a security dye and subsequent application of a sealing layer for producing such a strip, and its application for production of a packaging foil.

Description

The present invention relates to tear strips and is concerned with tear strips for applying security features to consumer goods, food packaging and the like.

The manufacture and sale of counterfeit goods represents an ever-growing one Problem. Such counterfeit products are often deceptively similar Kind of like the original goods packed so as to deceive potential buyers and them make you believe you are buying originals. This poses various problems. On the one hand, the manufacturer of the original products escapes the business. On the other hand the owner of the rights to the product is defrauded of its intellectual property. In Even more important in many cases is the fact that the imitations are often are of inferior quality and thus a considerable loss of image for the manufacturer inflict. Furthermore, the lower quality can lead to claims from the Product liability so that it is up to the manufacturer of the original to prove that the good causing the damage does not come from him. For these reasons out of it it is desirable to label original products in such a way that the Consumers will be able to recognize the originality and that it is in the event of damage it is possible to prove the originality.

Packaging made from plastic films, paper, cardboard or composites is often used of these packaging materials with tear strips. Attaching the strips to the Packing is done using a self-adhesive on the strip or an adhesive to be activated by heat. The patents US 4,887,714 and US 4,844,962 describe such tear strips.

The introduction of a security feature in a packaging in the form of a Adhesive tape is described in EP 0 585 076. Here are holographic Elements used as a security feature. A disadvantage of holograms is generally that the special effect in low light conditions loses. In addition, the production of holograms presents a complicated, complex manufacturing process. In particular in the manufacture of tear strips this process must be upstream and cannot be integrated into the existing Manufacturing processes are integrated. The carrier film must be primed and with be coated with an embossing lacquer. Then the holographic pattern embossed. The metallization must then be carried out as the next production step become. Only this material can then be used in the usual production process Tear strips are fed. The manufacturing process is expensive and around several steps more complex.

The task therefore was to provide a tear strip with a security feature To provide, whereby the introduction of the security feature no new, additional manufacturing step in the manufacturing process of the tear strip necessary makes.

The invention therefore relates to a tear strip with a security feature a carrier film with a sealing layer on one side and the other If applicable, a release layer is applied, characterized in that that the carrier film is printed on one side with a special security color.

The carrier film is preferably made of cellophane, polyvinyl chloride, vinyl chloride copolymer, Vinyl chloride terpolymer, polyester, polypropylene, polypropylene copolymer, Polypropylene terpolymer, polypropylene-polyethylene copolymer, polymaid, polystyrene, Polystyrene copolymer, polystyrene terpolymer, polycarbonate, polyketone, Polymethacrylate or polymethacylate copolymer. Particularly preferably from monoaxial oriented polypropylene or polypropylene-polyethylene copolymer.

In a special embodiment, the carrier film can be coated with one or more polymer films, with paper, with metallized polymer foils, with metal foils or in Vacuum-coated foils must be laminated.

The sealing layer is preferably a layer of self-adhesive pressure sensitive adhesives based on polyacrylates or natural or artificial resins.

The release layer which may be present is preferably a UV-crosslinkable one Silicone coating.

Another object of the invention is a method for producing a Tear strip with security feature, where you have a carrier film with security color printed, a sealing layer on the printing and on the other side if necessary, a release layer is applied to the carrier film.

According to the invention, printed tear strips are produced in such a way that one Operation printed a carrier film and a sealing medium such as on the printing ink e.g. Hot melt pressure sensitive adhesive applies. If necessary, is also on the other side a release coating is applied to the wearer to prevent blocking. By using suitable colors it is now possible to work within these Manufacturing method to integrate a security element in the tear strip.

In the case of execution as a counter print, this is carried out so that one at the finished packaging through the packaging film, the adhesive and finally recognize the printed security color through the carrier film can.

The carrier film can have a thickness between 10 and 100 microns and a width between 1 and 100 mm. The thickness is preferably between 10 and 40 μm and Width between 1.5 and 10 mm, very particularly preferably between 1 and 5 mm.

The sealing layer can be sealing media such as Polyethylene or um so-called hot-melt coatings, the layer thickness between 1 and is 20 µm and the sealing temperature is usually above 100 ° C.

Cold-glue, self-adhesive pressure-sensitive adhesives are preferred as the sealing medium on the basis of polyacrylates or very particularly preferably on the basis of natural or artificial resins.

In the case of self-adhesive pressure-sensitive adhesives, the back of the film is covered with a Release coating equipped. This is preferably a Silicone coating, very particularly preferred around UV-crosslinkable silicone coatings.

The carrier film can be printed in one or more colors. It is coming any printing process that can be used for foils. Especially done printing in typical packaging printing processes such as offset, screen, flexo, UV flexo or gravure. Especially in flexographic or gravure printing, especially in Gravure printing.

The security colors used are colors that are special Have properties that are suitable, the originality of the packaged item ensure.

The security colors used can be of different colors Trade effects. For example, thermochromic colors can be used change color reversibly or irreversibly at a certain temperature; Daylight fluorescent colors, the luminosity of which depends on the proportion of UV light in the lighting is so that the originality with the technical aids of today is far common color copier can be checked; Luminescent colors, the UV light absorb and emit longer-wave, visible light, resulting in lighting A certain color impression can be achieved with a UV lamp Light can either be emitted very quickly after absorption so that one speaks of fluorescence or it can last for a longer period, so that one speaks of phosphorescence; Infrared colors that under IR light show characteristic absorption behavior, so that a distinction from Colors are possible that look identical under daylight; photochromic colors that change their color reversibly by irradiation with UV light; metamere Colors whose hue depends on the viewing angle

Products can advantageously be produced by the tear strips according to the invention protected against counterfeiting. The purpose of the security element is if falsifications occur, prove their lack of originality in court to be able to but also to the consumer, an intermediary or to enable an authority like customs or police to use simple means Recognize the originality of a product.

The production of a tear strip of the construction described can on the usual machines happen. The release layer is applied with a Multi-roll applicator and subsequent drying or curing of the Layer.

The printing on one side of the carrier film can be done with the known printing machines respectively. One or more printing units, depending on the number of desired Effects are filled with security color and like a conventional color integrated into the printed image. The sealing medium is rotated in-line or off-line or by means of slot dies or other suitable methods the printing applied.

By introducing a security element according to the invention by means of a printing process without additional manufacturing steps, it is possible in a particularly simple and economical way to equip tear strips with a security element.

Another object of the invention is packaging material, the invention Tear tape contains such as in the packaging of cigarettes, compact Discs or foils used in food.

Examples example 1

A film made of monoaxially stretched polypropylene, with a thickness of 38 µm, where the maximum tensile force is greater than 160 N, the elongation at break> 25%, the tensile force at 10% elongation> 32N, the tear strength> 6N, the longitudinal tensile force> 1250 kJ / m ² , the transverse pull> 100 kJ / m ² , the shrinkage (at 125 ° C and 10 minutes) less than 6% and the pretreatment level greater than 38 mN / m, was coated with a mixture of silicones, which is solvent-free silicone acrylates with a polymeric photoinitiator that were radically crosslinked by UV radiation under a protective gas atmosphere and whose mixing ratio determines the separating effect of the hardened silicone acrylate layer.

The next step was the intaglio printing on the side opposite the silicone-coated side, the surface tension being previously set to a value> 38 mN / m ² by means of a corona treatment. A commercially available hotmelt adhesive based on SBS copolymers and condensation resins was applied to the printing ink. The application quantity was 10 g / m ² . In the subsequent steps, the film finished in this way was cut to a width of 2 mm and wound on spools of 6000 m.

Example 2

A cellophane film with a thickness of 30 µm was printed by gravure and a hot-melt adhesive was applied to the paint, also by gravure, the composition of which consists of 25-45% ethyl vinyl acetate copolymer, 20-35% cyclohexanone hydrocarbon resin, 15- 25% saturated hydrocarbon resin, 5-10% (-methylstyrene hydrocarbon resins and less than 10% oligomeric polyurethanes. The melting range is 70-80 ° C. The application amount was 4 g / m ² .

The film finished in this way was cut to a width of 2 mm in the subsequent steps and wound on spools of 6000 running meters.

Example 3

The procedure was as in Example 1. However, a commercially available acrylate dispersion was used as the pressure sensitive adhesive, the solids content of which was approx. 53% and the flow time in the DIN 4 cup was 60 seconds. The application weight was 3 g / m ² , the aqueous dispersion was applied by gravure printing.

Claims (11)

Tear strips with security feature made of a carrier film, on which on the one side a sealing layer and on the other side one if necessary Release layer is applied, characterized in that the carrier film is printed on one side with a security color. Tear strip according to claim 1, characterized in that the carrier film made of cellophane, polyvinyl chloride, vinyl chloride copolymer, vinyl chloride terpolymer, Polyester, polypropylene, polypropylene copolymer, polypropylene terpolymer, Polypropylene-polyethylene copolymer, polyamide, Polystyrene, polystyrene copolymer, polystyrene terpolymer, polycarbonate, Polyketone, polymethacrylate or polymethacrylate copolymer. Tear strip according to claim 2, characterized in that the film mono- or biaxially oriented polymeric materials. Tear strip according to claim 1, characterized in that the carrier film with one or more polymer films, with paper, with metallized Polymer films, with metal foils or foils vacuum-coated in a vacuum is covered. Tear strip according to one of claims 1 to 4, characterized in that that the sealing layer on a layer of self-adhesive pressure sensitive adhesives the basis of polyacrylates or natural or artificial resins. Tear strip according to one of claims 1 to 5, characterized in that that a release layer of a UV-crosslinkable on the carrier film Silicone coating is applied. Process for producing a tear strip with a security feature, characterized in that a carrier film with a security color printed, a sealing layer on the printing and on the other side of the Carrier film optionally applies a release layer. A method according to claim 7, characterized in that the security color by gravure printing. A method according to claim 7, characterized in that the security color in the flexographic process. Packaging material containing a tear strip with a security feature according to one of claims 1 to 7. Use of a tear strip with a security feature according to one of the Claims 1 to 6 for the production of a packaging film.