DE102008014390A1 - Adhesive tape for sealing packaging with a non-slip surface and using the same - Google Patents

Abstract

The invention relates to an adhesive tape, in particular for cardboard closure from a carrier film, on which an adhesive is applied on one side, characterized in that the adhesive mass-free back of the carrier film has a static coefficient of friction with respect to the surface of the same material of at least 1, preferably at least 1.5 and more preferably at least 2.

Description

The The present invention relates to an adhesive tape for sealing of packaging with anti-slip surface and use thereof.

A the essential conditions for a safe and efficient Goods transport is the choice of suitable packaging. For the primary and secondary packaging of goods The modern packaging industry today offers a great many, partly sophisticated solutions. As examples of The latter can be cited as so-called active packaging such as dust and moisture barrier films, the at the same time sweat off corrosion-protective substances.

Despite the variety of possible individual packaging, the vast majority of consumer goods for shipping are once again protected by an outer packaging in the form of cardboard boxes. Typically, to facilitate rapid loading and unloading of means of transport, multiple units of such cartons are stacked on pallets. To secure these stacks can be used depending on the requirements of other aids. For example, the cardboard boxes can be held together by strapping with strapped steel or plastic straps and on the pallets. Stretch and shrink films are particularly often used for wrapping, since they can be processed quickly and economically by machines and on the other hand provide additional protection against moisture and / or contamination. An alternative are prefabricated shrink hoods, which are particularly robust and provide a secure cohesion and increased protection against contamination. Should be mentioned that special strapping tapes such as that available from the tesa AG tesa ^® 51128 can be used for this application.

Also during in-house transport of stacks of goods on pallets, such as for further processing steps or just on the way to Einstretchstation, but also if no claim regarding Wet pollution protection can be a protection of the Stack to be advantageous against slipping or falling over. This is on the one hand, for efficiency reasons, as desired Realignment or re-stacking associated with effort is. On the other hand, also occupational safety aspects and logistical reasons play a role. So can for example also the possible later Einstretchen only the slipping fix state, and thus need wider stacks nevertheless unnecessarily much valuable transport space in the logistics chain.

Previous Solutions exist for the described problem for example in the application of special slip-resistant paints on the cardboard surface. The disadvantage here, however, is that affects the appearance of the cardboard surface and the achieved friction remains limited and. So usually no glossy surface of cardboard boxes possible.

Farther can be between the individual stack layers mostly on both sides provided with anti-slip coatings, papers or films be placed. However, these liners significantly increase the Time and effort of hoof stacking, since several times an intermediate step is introduced. In addition, the insertion of these slip-resistant happens Sections due to the large constructive effort of corresponding Machines predominantly by hand and therefore accordingly lower efficiency. It also increases with the slip-resistant sections the proportion of packaging materials to be disposed of later and interferes with the stacking.

Also proposed is the simple partial bonding of the boxes in the stack with each other, for example, selectively with nozzles or by spraying applied liquid Adhesives. This in turn also affects the optical Appearance of the packaging, as the cardboard surface during Separating the cardboard boxes is easily damaged or at Use of pressure-sensitive adhesive for unwanted tightening of Dirt at the sticky spots tends.

task The invention therefore provides an aid to put, with the slipping of stacked on each other Cartons within a carton stack can be prevented and which the mentioned disadvantages of the previous solutions does not have.

Solved this task is achieved by an adhesive tape with anti-slip backing, as characterized in detail in the main claim. In the Subclaims are advantageous embodiments of the invention. Furthermore, the use of the invention Adhesive tape of the inventive concept includes.

Accordingly, the invention relates to a cardboard closure adhesive tape made of a carrier film, on the one side an adhesive is applied, the adhesive-free Rear side of the carrier film has a static coefficient of friction opposite the surface of the same material of at least 1, preferably at least 1.5 and more preferably has at least 2.

According to one further advantageous embodiment of the invention has the adhesive-free reverse side of the carrier film a static coefficient of friction against paper of at least 0.35 and more preferably of at least 0.5.

For the expert surprising and completely unexpected shows that when using the inventive Adhesive tapes for closing later on one another Stacked cardboard boxes at least as high stacking protection is achieved, as they are for conventional slip-resistant Liner papers is known.

Ideally is in addition to the increased friction on its own back also a slip-inhibiting effect of the back of the carrier scored against the cardboard surfaces. This amplifies the total effective slip inhibition of the invention Adhesive tape in addition.

One Such product has significant advantages over all described alternative solutions. As usually cardboard boxes sealed with cardboard sealing tape, found at the Application of the adhesive tape according to the invention no additional process step in packaging instead. moreover The application can be done mechanically and with the same efficiency as done with standard closure tapes. simultaneously the visual impression of the packaging remains unimpaired, even the appearance of the tape according to the invention is indistinguishable from a standard packaging tape.

When Support material for the invention Adhesive tape is suitable for various film structures. It is preferred if the film of polypropylene or at least substantially Polypropylene exists.

The Carrier film can be made from a coextruded film or from consist of a laminated film.

• 1.) Basisschicht aus BoPP kaschiert mit einer PP-Castfolie
• 2.) Basisschicht aus BoPP kaschiert mit einer PP-Copolymer Castfolie
• 3.) Basisschicht aus BoPP kaschiert mit einer PE-Castfolie
• 4.) Basisschicht aus PET kaschiert mit einer PP-Copolymer Castfolie
• 5.) Basisschicht aus BoPP, rückseitig beschichtet mit Silikonkautschuk
• 6.) Basisschicht aus BOPP, rückseitig beschichtet mit Poly(Ethylen-co-vinylacetat)
• 7.) Coextrudierte Folie beinhaltend eine Basisschicht aus PP und eine Deckschicht aus PE oder PE-PP-Copolymer

Without wishing to limit the scope of the invention, the following advantageous carrier films may be mentioned by way of example:

• 1.) Base layer of BoPP laminated with a PP cast film
• 2.) Base layer of BoPP laminated with a PP copolymer cast film
• 3.) Base layer of BoPP laminated with a PE cast film
• 4.) Base layer of PET laminated with a PP copolymer cast film
• 5.) Base layer of BoPP, coated on the back with silicone rubber
• 6.) BOPP base layer, coated on the back with poly (ethylene-co-vinyl acetate)
• 7.) Coextruded film comprising a base layer of PP and a top layer of PE or PE-PP copolymer

at the choice of the surface is beside the achievement of a Surface with sufficient coefficient of friction opposite the same material, in particular to obtain a sufficient low separation force between the back of the carrier film and the pressure-sensitive adhesive layer. This is significant, therefore as that the tape must be easy to unroll.

Prefers is next to a top layer of slip-resistant polyolefin one Silicone-based reverse side coating.

The Carrier film is preferably used together with a polyolefin film coextruded, or the polyolefin film is preferably applied to the carrier film is laminated.

The Silicone can be solvent-free (100% or as a dispersion) or solventborne and by blasting, thermally, for example via a condensation, addition or radical reaction or physically (for example by a block structure).

Possibly The silicone coating can also be applied by coextrusion (For example, with an outer layer containing polyvinyl stearyl carbamate or silicone-grafted polyethylene).

Solvent-free silicones with thermal or radiation-induced crosslinking become particularly preferred, in particular vinylpolydimethylsiloxanes. These are preferably crosslinked with methylhydrogensiloxanes in the presence of a platinum or rhodium catalyst or by EB / UV radiation.

usable for example, this is the one available on the market addition-curing silicone release system "Dehesive 940A" Wacker chemistry with an associated catalyst system, which is applied in the uncrosslinked state and then subsequently crosslinked in the applied state.

When Crosslinkable silicone can be the usual used for release coating silicone systems. These include mixtures of crosslinking catalysts and so-called thermally curable condensation or addition-curing Siloxanes. Furthermore, photoactive catalysts, so-called photoinitiators, in combination with UV-curable cationically crosslinking siloxanes based on epoxide and / or vinyl ether or UV-curable free-radical crosslinking siloxanes such as acrylate-modified siloxanes are used. Likewise is the use of electron beam curable silicone acrylates possible. Appropriate systems can vary depending on Intended use also other additives such as stabilizers or flow control agents.

Furthermore, various types of Organopolysiloxanmassen are known, which crosslink by heating or irradiation. Called masses, as they are for example in the EP 0 378 420 A1 which crosslink by addition reaction, namely by temperature treatment of a mixture of an organopolysiloxane having hydrogen atoms bonded directly to the silicon atoms and an organopolysiloxane having vinyl groups bonded directly to the silicon atoms in the presence of a hydrosilylation catalyst.

Also, photopolymerizable organopolysiloxane compositions can be used. Mention may be made, for example, of compositions which are bonded directly to the silicon atoms by the reaction between organopolysiloxanes which have hydrocarbon radicals substituted by (meth) acrylate groups and are crosslinked in the presence of a photosensitizer (cf. EP 0 168 713 B1 . DE 38 20 294 C1 ). Also useful are compositions in which the crosslinking reaction between organopolysiloxanes having hydrocarbyl substituted with mercapto groups bonded directly to the silicon atoms and organopolysiloxanes having vinyl groups attached directly to the silicon atoms is induced in the presence of a photosensitizer. Such masses are used for example in the US 4,725,630 A1 described.

When using the example in the DE 33 16 166 C1 Organopolysiloxane compositions containing epoxy groups substituted hydrocarbon radicals bonded directly to the silicon atoms, the crosslinking reaction is induced by release of a catalytic amount of acid, which is obtained by photo-decomposition of added onium salt catalysts. Other cationic-mechanism-curable organopolysiloxane compositions are materials having, for example, propenyloxysiloxane end groups.

• a) Einem linearen oder verzweigten Dimethylpolysiloxan, welches aus ca. 80 bis 200 Dimethylpolysiloxan-Einheiten besteht und an den Kettenenden mit Vinyldimethylsiloxy-Einheiten abgestoppt ist. Typische Vertreter sind zum Beispiel lösungsmittelfreies, additionsvernetzendes Silikonöl mit endständigen Vinylgruppen, wie DEHESIVE^® 921 oder 610, beide kommerziell erhältlich bei Wacker-Chemie GmbH.
• b) Einem linearen oder verzweigten Vernetzer, welcher üblicherweise aus Methylhydrogensiloxy- und Dimethylsiloxy-Einheiten zusammengesetzt ist, wobei die Kettenenden entweder mit Trimethylsiloxy-Gruppen oder Dimethylhydrogensiloxy-Gruppen abgesättigt sind. Typische Vertreter dieser Produktklasse sind zum Beispiel Hydrogenpolysiloxane mit hohem Gehalt an reaktivem Si-H wie die Vernetzer V24, V90 oder V06, welche bei Wacker-Chemie GmbH kommerziell erhältlich sind.
• c) Einem Silikon-MQ-Harz, welches als M-Einheit neben den üblicherweise verwendeten Trimethylsiloxy-Einheiten auch über Vinyldimethylsiloxy-Einheiten verfügt. Typische Vertreter dieser Gruppe sind zum Beispiel die Trennkraftregler CRA^® 17 oder CRA^® 42, kommerziell erhältlich bei Wacker-Chemie GmbH.
• d) Einem silikonlöslichen Platinkatalysator wie zum Beispiel einem Platindivinyltetramethyldisiloxan-Komplex, welcher üblicherweise als Karstedt-Komplex bezeichnet wird und beispielsweise unter der Bezeichnung Katalysator OL bei Wacker-Chemie GmbH kommerziell erhältlich ist.

Thermally curing release coatings are often multicomponent systems, which typically consist of the following components:

• a) A linear or branched dimethylpolysiloxane, which consists of about 80 to 200 dimethylpolysiloxane units and is stopped at the chain ends with vinyldimethylsiloxy units. Typical representatives are, for example, solvent-free, addition-silicone oil with terminal vinyl groups, such as DEHESIVE ^® 921 or 610, both commercially available from Wacker-Chemie GmbH.
• b) A linear or branched crosslinker, which is usually composed of methylhydrogensiloxy and dimethylsiloxy units, wherein the chain ends are saturated with either trimethylsiloxy groups or dimethylhydrogensiloxy groups. Typical representatives of this product class are, for example, hydrogenpolysiloxanes with a high content of reactive Si-H, such as the crosslinkers V24, V90 or V06, which are commercially available from Wacker-Chemie GmbH.
• c) A silicone MQ resin, which also has vinyldimethylsiloxy units as the M unit in addition to the trimethylsiloxy units usually used. Typical representatives of this group are, for example, the separation force regulator CRA ^® 17 or CRA 42 ^®, commercially available from Wacker-Chemie GmbH.
• d) A silicone-soluble platinum catalyst such as a platinum divinyl tetramethyl disiloxane complex, which is commonly referred to as Karstedt complex and commercially available, for example, under the name catalyst OL at Wacker-Chemie GmbH.

The silicones used according to the invention, preferably silicone oils, are polydisperse mixtures of differently long and differently substituted, linear or cyclic siloxane chains. The mixtures are formed in catalyzed synthesis processes. The polysiloxanes consist of alternie atoms of silicon and oxygen, so that the characteristic feature is the Si-O-Si - (= siloxane) bond in the molecular structure. Different substituents are possible at the two remaining valences of the silicon.

Chemically correct, the treated silicone oils are therefore polydimethylsiloxanes, which are generally abbreviated as PDMS. They are characterized by the following formula: Structure of linear (left) and cyclic polydimethylsiloxanes (right)

The Residues on the silicon can also be linked to other siloxane bonds be saturated; in this way one comes to branched and crosslinked silicones. The former then form the silicone resins, the latter the silicone elastomers.

• • [M] = R₃SiO_1/2
• • [D] = R₂SiO_2/2
• • [T] = RSiO_3/2
• • [Q] = SiO_4/2

Depending on the functionality of the silicon group (mono-, di-, tri- or tetrafunctional), the symbolic notations M, D, T and Q have been introduced:

• • [M] = R ₃ SiO _1/2
• • [D] = R ₂ SiO _2/2
• • [T] = RSiO _3/2
• • [Q] = SiO _4/2

• • lineare Polysiloxane: sind kettenförmig aus difunktionellen Siloxaneinheiten aufgebaut und enthalten monofunktionelle Endgruppen; Bautyp [MD_nM] od. R₃SiO[R₂SiO]_n SiR₃, im Formelbild (R=CH₃).
• • verzweigte Polysiloxane: sind ring- oder kettenförmig aus di-, tri- oder tetrafunktionellen Siloxan-Einheiten aufgebaut; Bautyp [M_nD_mT_n].
• • cyclische Polysiloxane: sind ringförmig aus difunktionellen Siloxan-Einheiten aufgebaut; Bautyp [D_n].
• • vernetzte Polymere: sind ketten- oder ringförmige Moleküle, die mit Hilfe von T- und Q-Einheiten zu zwei- oder dreidimensionalen Netzwerken verknüpft sind.

One can distinguish the following groups:

• • linear polysiloxanes: are constructed in chain form from difunctional siloxane units and contain monofunctional end groups; Building type [MD _n M] od. R ₃ SiO [R ₂ SiO] _n SiR ₃ , in the formula image (R = CH ₃ ).
• Branched polysiloxanes: are constructed in a ring or chain form of di-, tri- or tetrafunctional siloxane units; Type of construction [M _n D _m T _n ].
• • cyclic polysiloxanes: are ring-shaped of difunctional siloxane units; Type of construction [D _n ].
• • cross-linked polymers: are chain or ring-shaped molecules that are linked to two- or three-dimensional networks by means of T and Q units.

The to be provided with a silicone coating side of the film becomes better adhesion of the coating preferably on the surface pretreated. These can be chemical coatings or Treatments from the gas phase (for example, fluorine-containing gases) or physical processes such as flame or plasma and in particular Corona treatment.

The Thickness of the carrier film is preferably between 30 and 200 μm, more preferably between 40 and 140 μm, most preferably between 50 and 90 microns.

As adhesive tape, a film with a self-adhesive adhesive layer is preferred according to the invention. For the adhesive tape application, the carrier film is coated on one side with pressure-sensitive adhesive as a solution or dispersion or 100% (for example from the melt) or by coextrusion with the carrier film. The adhesive layer can be crosslinked by heat or high-energy radiation and, if necessary, covered with release film or release paper. Suitable pressure-sensitive adhesives are, in particular, pressure-sensitive adhesives based on acrylate, natural rubber, thermoplastic styrene block copolymer or silicone.

to Optimization of the properties may be the self-adhesive used with one or more additives such as tackifiers (resins), plasticizers, Fillers, pigments, UV absorbers, light protection, aging protection, Crosslinking agents, crosslinking promoters or elastomers blended be.

suitable Elastomers for blending are, for example, EPDM or EPM rubber, Polyisobutylene, butyl rubber, ethylene-vinyl acetate, hydrogenated block copolymers from dienes (for example by hydrogenation of SBR, cSBR, BAN, NBR, SBS, SIS or IR, such polymers are for example SEPS and SEES known) or acrylate copolymers such as ACM.

Tackifiers are, for example, hydrocarbon resins (for example, unsaturated C ₅ or C ₇ monomers), terpene-phenolic resins, terpene resins from raw materials such as α- or β-pinene, aromatic resins such as cumarone-indene resins or resins of styrene or α-methylstyrene such as rosin and its derivatives such as disproportionated, dimerized or esterified resins, whereby glycols, glycerol or pentaerythritol can be used. Particularly suitable are age-stable resins without olefinic double bond such as hydrogenated resins.

suitable Fillers and pigments are, for example, carbon black, Titanium dioxide, calcium carbonate, zinc carbonate, zinc oxide, silicates or Silica.

suitable UV absorber, sunscreen and anti-aging agent for the adhesives are those described in this document the stabilization of the film can be listed.

suitable Plasticizers are, for example, aliphatic, cycloaliphatic and aromatic mineral oils, di- or poly-esters of phthalic acid, Trimellitic acid or adipic acid, liquid Rubbers (for example nitrile or polyisoprene rubbers), liquid Polymers of butene and / or isobutene, acrylic esters, Polyvinyl ethers, liquid and soft resins based on raw materials to adhesive resins, wool wax and other waxes or liquid Silicones.

crosslinking agent are, for example, phenolic resins or halogenated phenolic resins, melamine and formaldehyde resins. Suitable crosslinking promoters are, for example Maleimides, allyl esters such as triallyl cyanurate, polyfunctional esters of acrylic and methacrylic acid.

According to preferred Embodiments, the pressure-sensitive adhesive contains bright and transparent raw materials. Particularly preferred are acrylate adhesive (for example as a dispersion) or styrene block copolymer pressure-sensitive adhesive and resin (for example, as is common for hot melt pressure sensitive adhesives are).

The coating thickness with adhesive is preferably in the range of 15 to 50 g / m ² , in particular 18 to 29 g / m ² . The width of the adhesive tape rolls is preferably in the range of 20 to 60 mm.

Of the general term "adhesive tape" includes the meaning this invention all planar structures as in two dimensions extended films or film sections, tapes with extended Length and limited width, band sections, die cuts, Labels and the like.

in the The invention will be more closely understood by way of examples without being limited in any way to act.

example 1

Of the Carrier consists of a "cast-random PP film" with a thickness of 60 microns, to which a 25 micron thick BOPP film is laminated. On this is an adhesive in the form of a Dispersion acrylate adhesive (for example Primal PS 83 D from Rohm & Haas), which is applied with a thickness of 23 microns. The adhesive power is 2.5 N / cm.

Example 2

The support consists of a "cast-random PP film" with an admixture of 15 wt .-% PE (Exxon Vistamaax 1100) with a thickness of 60 microns, to which a 40 micron thick hard PP film is laminated. On this is an adhesive in the form of a dispersion of acrylate adhesive (for example, Primal PS 83 D from Rohm & Haas) used, which is applied with a thickness of 23 microns. The bond strength is 2.5 N / cm

Test Methods

Determination of static friction coefficients

The Measurement of the static coefficient of friction is done by means of a Friktionstesters. The towing weight is 200 g, the Towing speed is 0.1 m / min.

Determining the quality of the stack safety device through practical sliding tests with cardboard boxes

A) Determination of breakaway force

The upper and lower flaps of two standard corrugated boxes (700 × 400 × 300 mm, L × W × H) are each closed in the U-lock with a 50 mm wide packaging tape. The cartons are previously filled to simulate the packaged goods with 10 kg of uniform contents (for example, dried peas) and stacked horizontally. Immediately afterwards, with an electronic force measuring device, the force which must act in the horizontal direction on the upper carton in order to set this straight in motion, that is to move relative to the lower carton. product breakout force Conventional packaging tapes tesa 64014 15 N tesa 4100 17 N tesa 4263 19 N tesa 4234 25 N tesa 4298 26 N tesa 64285 orange 34 N tesa 64285 transparent 33 N Anti-slip paper 60 N Inventive adhesive tape 1 70 N Adhesive tape 2 according to the invention 102 N

B) Determination of the minimum slip angle

The upper and lower flaps of two standard corrugated boxes (700 × 400 × 300 mm, L × W × H) are each sealed in the U-lock with a 50 mm wide packaging tape. The cartons are previously filled to simulate the packaged goods with 10 kg of uniform contents (for example, dried peas) and stacked horizontally. The lower carton is fixed on a tiltable plate. The angle of the plate to the horizontal is then increased very slowly (about 1 ° / s). It measures the minimum angle at which the top begins to slip on the bottom carton. product angle Conventional packaging tapes tesa 4100 7 ° tesa 64285 orange 15 ° tesa 64014 16 ° tesa 4298 16 ° Anti-slip paper 30 ° Inventive adhesive tape 1 42 ° Adhesive tape 2 according to the invention 56 °

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• EP 0378420 A1 [0026]
• EP 0168713 B1 [0027]
• - DE 3820294 C1 [0027]
• US 4725630 A1 [0027]
• - DE 3316166 C1 [0028]

Claims (8)

Adhesive tape, in particular for carton closure, from a carrier film to which an adhesive is applied on one side, characterized in that the adhesive-free reverse side of the carrier film has a static coefficient of friction with respect to the surface of the same material of at least 1, preferably at least 1.5 and more preferably at least 2 , Adhesive tape according to Claim 1, characterized that the adhesive mass-free back of the carrier film a static coefficient of friction against paper of at least 0.35 and more preferably of at least 0.5. Adhesive tape according to Claim 1 or 2, characterized the backing film has a thickness of 30 to 160 μm, preferably 40 to 140 μm, particularly preferably 50 to 90 microns. Adhesive tape according to at least one of the claims 1 to 3, characterized in that the carrier film Polypropylene exists. Adhesive tape according to at least one of the claims 1 to 3, characterized in that the carrier film in Essentially made of polypropylene. Adhesive tape according to at least one of the preceding claims, characterized in that on the adhesive mass-free back the carrier film is a polyolefin film or a backside coating is available on silicone basis. Adhesive tape according to at least one of the preceding claims, characterized in that the carrier film together with a polyolefin film is coextruded or that the polyolefin film is laminated to the carrier film. Use of an adhesive tape after at least one the previous claims in particular to the closure or to equip cardboard boxes with a non-slip surface.