DE2444616A1 - DUE TO VOLTAGE, THE DISPLAY ELEMENT BECOMES NAKED TO PROOF THE UNAUTHORIZED OPENING OF A CONTAINER - Google Patents

Description

1 BERLIN 33 β MUNICH 80

Auguste-Viktoria-Strasse 65 _n DIIC O U k " P Λ, PAPTMFR Pienzenauerstrasse 2

Pat-Anw.Dr. Ing.Ruschko Dr. RU SUH Kt & PAK IN L K Pat.-Anw.Dipl.-lng.

Pat. Dipl.-Ing. P AT F N TA N WÄ LT E Hans E. Ruschke

Olaf hiuschke r AIE IN IM IN VVM _{l_IC T} «l _B fnn · 089/38 03 24

Phone. 030 / g »» »BERL I N - M Ü MUNICH · ^{Telephone 089/98} ₇₂₅₈

Telegram address: Telegram address:,

Quadrature Berlin Quadrature Munich TELEX: 183786 TELEX: 522767

24U616

Minnesota Mining and Manufacturing Company, St. Paul, Minnesota, V.St.A.

Display element becoming opaque due to tension as proof of unauthorized opening of a container

The present invention relates to an improved container closure.

In the past, containers were often found with easy-to-open strap closures sealed with a thermosetting or pressure sensitive Applying adhesive over a hole in the container lid; see the US-PS 3,389,827. Such a closure typically has a free end which can be grasped with the fingers to remove the closure, whereafter the container contents - For example, fruit juice, oil, salt and the like - through the now exposed hole can be emptied.

Although such tape closures are effective and easy to open Represent closure, it is possible to carefully open the container contents to remove or falsify and then the tape with no visible traces to raise again.

U.S. Patent 3,680,236 discloses a closure that changes color when attempted will remove it with an organic solvent. The servers-

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The end has a dye-containing layer that comes into contact with a organic solvents - for example kerosene or toluene - dissolve and color the tape. In most cases the attempt to access the container will be unauthorized to open, but purely mechanical means are used.

Another type of tape fasteners is the one with heat on the neck of various types Bottles with seasonings, wine or other edible substances are shrunk open Sleeve. This seal generally cannot be restored once it has been broken. Each type of bottle requires it a specially adapted sleeve that is only suitable for a certain bottle size and shape. In the past, you had the pods before and after Shrinking held in place mechanically.

The present invention provides a simple method by which to determine lets whether any of several types of tape fasteners have been broken has been. In any case, the closure visibly indicates when it has been mechanically tampered with, thus increasing the security and trust of the End user in the product. When applying heat-shrinkable closures the sleeve is held in place with an adhesive until it has shrunk, eliminating the need for a separate holding device is eliminated.

The present invention, in one aspect, consists of an improved form well-known tape fasteners. The invention provides a closure which is provided on an exposed surface with a layer of a substance which is initially clear or translucent but under tension (as occurs when the seal is removed to open the container) becomes opaque. Before applying tension to the under tension When the material becomes opaque, the substrate is visible. However, after the voltage is applied, the material becomes opaque or white pastel! colored. The substrate surface lying under it, which was previously visible is now covered, resulting in an appearance change indicating that an attempt has been made to open the tape fastener. This display remains even if the closure is reapplied afterwards. The entire closure can be made opaque under tension

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Material to be made. Alternatively, this can be opaque under tension The material will be part of a separate indicia layer provided on an otherwise conventional tape fastener.

The tape closure selected can be, for example, that in the aforementioned US-PS 3,389,827 belong to the type described, the disclosure of which is incorporated into the present application by reference. The closure according to the present Invention can also take the form of an elongated, with a pressure-sensitive Adhesive coated strip or tape is present that the joint between a can and a lid in slide-on lid or collar cans ("slipcover or collar cans"), as they are conventionally used for packaging Coffee, ham etc are used; See U.S. Patent 3,516,852. The strip is also useful for attaching conventional fitting caps or lids to food containers made of plastic or cardboard (e.g. for yoghurt or white cheese) to hold on. In this case the closure of the present invention is formed off by putting a strip of heat shrinkable tape on the butt pieces between the container body and lid around the container so that he extends under and possibly also over the edge. When heat is applied, the band shrinks around the edge and thus forms a tight seal the end. The heat-shrunk band collar can thus primarily open as a closure (as with sliding lid cans) or as a display element for unauthorized persons (as in the case of bottles, etc.), in which case it forms a second airtight seal. So if the main seal leaks, how it can happen, for example, if the sealing bead on a bottle splinters, the tape protects the contents of the container.

Where the indicator layer is a separate closure on the used one attached layer is, at least a part of the display layer is partial attached to the free end of the tape fastener so that it flexes and begins to opaque before a substantial part of the Lock has been removed. This ensures that the contents of the closed container cannot be falsified undetected.

The display layer, which becomes opaque under tension, advantageously becomes from a 1 ... 10 mil (25 ... 250, u) thick film of normally

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transparent, which becomes opaque under tension and not plasticized Made of polyvinyl chloride; other suitable materials that become opaque under tension are films made of polybutadiene-polystyrene, Polyvinyl chloride-polyvinyl acetate and isotactic polypropylene-butyl rubber compounds.

Where the film becomes opaque under tension the entire tape closure represents, it is generally thicker than where it is only provided as a layer on a load-bearing tape fastener. The thickness of the inserted Film necessarily depends on the internal pressure of the container to be sealed away. For example, cans of carbonated drinks require a thicker and stronger closure than packs of non-pressurized dry materials such as cereal breakfast foods.

If a separate display layer is used, it is advantageous to attach it by means of a pressure sensitive adhesive on the tape fastener, although others thermosetting and thermoplastic adhesives can be used. The glue should of course attach the display element to the tape fastener so firmly and with good adhesion, that when the tape fastener is flexed, the indicator strip is placed under tension beyond the point at which the opacity is achieved entry. Adhesives which do not adequately adhere the display layer to the tape fastener allow the same to throw off or off the tape fastener to replace. As a result, the display layer will not be fastened with the tape bent and gives no visible indication of attempted opening. In categories of the effect to be achieved: the glue should be so firmly attached to both the Indicator layer as well as the tape fastener adhere that the force that is required to peel the display layer from the closure is greater than the force under which the display layer becomes opaque.

The peel adhesion of the adhesive can be determined according to a modified version of the 180 ° test PSTC-I of the Pressure-Sensitive Tape Council. One obtains a strip forth _s by a 1 ... 3 mil (25 ... 75, u) thick biaxially oriented polyethylene terephthalate film at a dry coating weight of 10 ... 12 grains per 24 square inches (about 40 ... 50 g / m) coated with the adhesive to be tested, from the film a 10 inch (about 25 cm) long and

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Cut a 1 inch (2.5 cm) wide strip and place it on a clean steel plate of 2x5 inches (about 5 χ 12.5 cm) so that 5 inches (about 12.5 cm), rolling the strip to ensure that there are no air pockets. The test specimen is aged for 24 hours at room temperature, then the free end of the tape strip over the glued-on part laid back, pulled past the end of the plate, and set in the pair of jaws of an Instron tensile tester. The free end of the steel plate (at the bend of the tape) is then set in the second pair of jaws of the testing machine, so that the tape is pulled off the steel plate when the pairs of jaws are removed apart. The jaws run at a speed of 12 inches (about 30.5 cm) apart per minute; provides the required force a measure of the peel adhesion. Adhesive with a peel adhesion of at least about 50 oz. per inch of width (about 560 g per cm of width) have been found to be im generally found suitable to a display layer on the tape fastener to be attached so that the tension is sufficient to become opaque. Under the layer that becomes opaque under tension is the colored one Substrate. In the unbent and thus translucent state, it is colored Substrate visible along the entire closure. However, if the layer is bent, it becomes opaque, covering the color underneath and thus "results in an altered appearance indicating that attempted." has been to open the shutter which contains the layer which becomes opaque under tension.

It is still possible to use characters such as the words "Open" or "Opened" on the surface of the layer which is opaque under tension to be printed on, these characters being the same color as the one below Have substrate. The characters are then invisible before the closure is opened, but are in color on the opaque white or paste-colored Background shows when the shutter has been bent.

It is also within the scope of the invention to produce closures, the colored Have layers both above and below the layer which becomes opaque under tension, the exposed colored layer being transparent is, so that the display element is initially the sum color of the two individual colors shows. When it becomes opaque, only the upper color is then

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visible. Further information on such color systems and materials for their Manufacture can be found in U.S. Patent 3,468,744, which is incorporated by reference in the present application.

The invention will now be described with reference to the accompanying drawings in which like reference numerals indicate like parts.

Fig. 1 is a top plan view of a can end having an opening which is associated with the Tape fastener according to the present invention is closed;

Figure 2 is a sectional view of the can end of Figure 1 taken along the line 2-2 in the direction of the arrows;

Figure 3 is a perspective view of a roll of tape as it is being used to manufacture the can closure of the present invention is suitable;

Fig. 4 is a perspective view of a sliding lid can with a closure is sealed according to the present invention ;.

Fig. 5 is a partial cross-sectional view of a food container with the lid in place and shows a heat shrinkable tape in the process of shrinking ready Arrangement;

FIG. 6 shows the container of FIG. 5 after the tape has been shrunk on.

Fig. 1 shows a can lid 10 with an opening 12, which is secured by a tape fastener 14 is tightly closed, with the transparent display layer 16, which becomes opaque under tension, firmly on the surface of the closure is glued on.

The display strip 16 consists of that which becomes opaque under tension Layer 20 overlying colored layer 22 and glued to it. The latter is firmly attached to the tape fastener 14 by means of an adhesive layer 24 upset. The tape closure 14 consists of a layer of a strong film 26 which is fastened to the can lid 10 around the opening 12 with an adhesive 24 is.

In an alternative embodiment, the film 26 is the closure 14 for its part is a strong one that becomes opaque under tension Material, eliminating the need for a separate display layer. In the-

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This embodiment is the colored layer 22 between the adhesive 28 and the film 14, the shutter 14 itself becoming opaque when bent which gives a visible indication of the attempted opening.

As shown in Fig. 3, the tape fastener 14 of Figs. 1 and 2 with his Display strip 16 advantageously made from a roll 30 of material stamped unwound strips. The one suitable for forming a tape fastener Film 23 has a continuous display 16 of under tension opaque material on the exposed surface is stuck on. A layer of adhesive 33 suitable for applying the closure to a can lid is fixed to that of the indicator strip 16 opposite surface of the film 32 glued. The ribbon closures are conveniently made from a strip from the roll 30 in the desired shape punched out; See for example Fig. 3 (The role is natural conventionally wound onto a core with the adhesive side inward and in Fig. 3 only for easier understanding shown as can be seen).

4 shows the sliding lid can 35 with the lid 36 and the body 38 closed with a strip fastener 34 covering the line (not shown), along which the lower edge of the lid 36 overlaps the upper edge of the body 38. The closure 34 has a pull tab 40 with a display element 41 between tab 40 and point 42 where closure 34 overlaps and is lightly glued to itself to achieve a hermetic seal. Part of the lid 36 and the container 38 is flat with a Provided recess, so that the strip fastener 34 does not cover the main circumferential surface the can protrudes and thus the strip 34 against accidental Protects damage during transport. Further details of this type of closure construction can be found in the aforementioned US Pat. No. 3,516. 852, the disclosure of which is incorporated into the present application for reference is.

5 and 6, a food container 44 is shown with a easily removable cover 46 closed with a recess provided in the middle is. A strip of heat-shrinkable tape 47 with one-sided

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The pressure sensitive adhesive 48 applied is wrapped and glued around the edge 49 which the lid and container form along the joint line of the two parts. As shown in Fig. 5, the tape 47 is applied along the edge 49 with overlapping ends so that the film forms a continuous sleeve after heat shrinkage. After it has been applied to the edge 49, the band 47 is ^{heated, for example, with a hot air jet at about 100 ... 20O 0} C, the film shrinking and enclosing the edge, as FIG.

The invention will now be described with reference to the following examples, that are not intended to restrict them. Parts and percentages are parts and percentages by weight, unless stated otherwise.

example 1

A 7.5 mil (about 19G, u) film of oriented rigid, unplasticized polyvinyl chloride (commercially available from BASF under the name "Luvitherm") was coated on one side with a black vinyl paint made from carbon black pigment in one side phthalate plasticized polyvinyl chloride / polyvinyl acetate binder resin solution-coated ( "reverse roll coated"), then 15 min kept in a hot air oven at 65 ⁰ C to drive off the solvent. the remaining top draw dry weight was 0.25-0.30 grams of paint per 24 square inches (about 50 mg / cm). A suitable color can be produced by diluting black vinyl paint of the type MRX-9243 from Crescent Ink and Color Company with a solids content of 39 % to a solids content of 24 % , for which purpose a mixture of equal volumes of toluene and methyl ethyl ketone is used.

A thin primer layer of polyamide with a dimer base at 7.5 % solids content (available under the name "Versalon 1140" from General Mills) in a solvent mixture of isopropanol and toluene in a ratio of 2: 1 was applied to the paint. A pressure sensitive adhesive was then prepared by dissolving (1) 100 parts of an ABA block polymer ₉ in which A was 15,000 molecular weight polystyrene and B 30,000 molecular weight polybutadiene (available from Shell Chemical Company under Trade name "Kraton 1101"), and (2) 95 parts ci-terpene in toluene The mixture was mixed with toluene to a solids content of 40 %

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diluted, brushed onto the primed and coated surface with a knife and then ^{dried at 65 °} C. for 20 minutes to remove the toluene

to evaporate, which is 12 grains of adhesive per 24 square inches (about 50 g / m) of weight revealed. The resulting strip was applied to the surface of a container closure in accordance with the description of US Pat. No. 3,389,827, Example II, applied, the closure made of a vapor-deposited with aluminum, biaxial oriented polyethylene terephthalate film having a structure similar to FIG. 2 duration.

When viewed from the exposed side, the indicator strip appeared after application initially black on the closure, since the black color applied to the covered surface of the transparent "Luvitherm" polyvinyl chloride film was visible. However, when the closure was bent on removal, it took the polyvinyl chloride film had an opaque white appearance, masked it the black color, indicating that the closure had been partially removed.

Example 2

A polyvinyl chloride base film was prepared by blending together

Parts of polyvinyl chloride resin available from Union Carbide Co. 100

Acrylate-butadiene-styrene copolymer, available as

"Acryloid KM 228" from Röhm & Hass 9

Montan wax acid derivative, available as "E" wax from

BASF Wyandotte Corp 5

Barium: cadmium stabilizer, available as "Mark 99" from

Argus Chemical Co. 3

Acrylic ester polymer available as "Acryloid K-120N" from

Röhm & Hass 2

Epoxy stabilizer, available as "Drapex .3-2" from

Argus Chemical Co. 2

Phosphite chelate available as "Mark C" from Argus Chemical Co. 1

The mixture was calendered into a 7 mil (190 µ) thick polymer film. The calendered film was stretched in the longitudinal direction in the ratio 2.5: 1, whereby the film thickness decreased to about 2.75 mils (about 0.07 mm) and the

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Film became heat shrinkable.

The stretched film was coated with black vinyl paint as in Example 1 ("reverse roll coated"). A pressure sensitive adhesive was prepared by dissolving 100 parts of the ABA block polymer of Example 1 and 95 parts of alpha pinene resin in toluene (commercially available as "PiccolyteoCl35" from Pennsylvania Industrial Chemical Co.). The mixture was diluted with toluene to a solids content of 40%, brushed onto the primed and coated area with a knife and ^{dried at 65 °} C. for 20 minutes to drive off the toluene, which equates to 8 grains of glue per 24 square inches (approx

2
27.5 g / m).

A 2 inch (about 5 cm) long strip of the tape was placed around the neck of a ketchup bottle with about 3/8 inch (about 9 mm) overlapping ends with about 1/16 inch (about 0.16 cm) beyond the cap presided. The bottle held in position band (about 16O ⁰ C) about 3 lake in a hot air stream at about 300 ⁰ F. long turned. The tape shrunk, fitted tightly to the bottle and cap, and made an airtight seal.

If the end of the tape is peeled off the bottle, the film becomes as a result of the occurring tension l. opaque, which the film surface - instead of black - now makes it appear white.

Claims

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Claims (7)

Claims 1. \ Container with content that has an opening that is opened by means of a deflection is closed, characterized in that at least part of the Cover is provided on the surface with an indicator strip, the one under tension has become opaque underlay, whereby when the display layer is bent to open the shutter, the pad is opaque and represents a color difference between the bent and the unbent part, which indicates the bending even when the cover is returned to its closed position. 2. Closure according to claim 1, characterized in that the display strip consists of heat-shrinkable tape that has been exposed to heat, causing the tape forms a tight seal. 3. Closure according to claim 1, characterized in that the display strip on the exposed area with printed characters in the same Color like that of the colored base is provided, whereby if the display element is unbent, the characters are invisible and if the indicator is bent, the characters appear visibly against an opaque background. 4. Sealed container according to claim 1, characterized in that the The container furthermore has a rigid wall with an opening formed therein and the cover over the opening has a tape fastener with a free one The end, wherein the closure consists of a sheet material which is removably glued directly onto a part of the wall which surrounds the opening, and at its free end can be grasped and withdrawn on itself without tearing is to the underlying material and by means of an adhesive on the Closure to reveal glued display layer. 5. A closure according to claim 4, characterized in that the adhesive, the the strip attached to the closure, a peel adhesion of at least 50 oz. per inch width (560 g / cm). 509818/0274 -12- 24U616 6. A closure according to claim 1, characterized in that the under tension The material that becomes opaque is an oriented polyvinyl chloride polymer film is. 7. A closure according to claim 1, characterized in that it is the Container is a sliding cover can ("slip cover can"), which with a Piece of tape closed with a free end that is suitable for gripping with the display layer adhered to the shutter so that at least a part of the display layer is flexed before any part the closure from the can. M 3492 Cl / Nep 509818/0274