Adhesive tape roll, the lateral face of which has an edge passivation

Abstract

The present application relates to adhesive tape rolls (1) which comprise an adhesive tape wound onto itself to form a roll, wherein at least one of the lateral faces (3) of the adhesive tape roll (1) is provided with a paint layer (2) which has cavities.

Description

[0001] ADHESIVE TAPE ROLL WITH EDGE PASSIVATION ON THE SIDE

[0002] The present application relates to an adhesive tape roll comprising an adhesive tape wound onto itself to form a roll, the side surface of which has a special edge passivation, and to a method for producing such passivated adhesive tape rolls.

[0003] The portfolio of adhesive tapes includes cable wrapping tapes and joining technology, as well as construction adhesive tapes. This type of adhesive tape is primarily used in energy-efficient construction. In addition to insulation bonding, membranes can also be bonded. To achieve good bonding on such substrates, high application weights and comparatively low crosslinking levels are required, especially when using non-metallic materials, to achieve correspondingly high adhesive strength.

[0004] The use of adhesives containing acrylates has proven beneficial in this regard and is therefore used in a variety of ways. During the production of acrylates, one-sided UV irradiation creates a crosslinking gradient within the adhesive layer, which leads to the desired adhesive behavior. This gradient also results in the presence of a weakly crosslinked adhesive on one side within the adhesive layer. This resulting, weakly crosslinked adhesive, in addition to its good adhesive properties, has the disadvantage of a high tendency to flow. Such a high tendency to flow can cause the adhesive to leak out from the sides of the finished adhesive tape roll, which can lead to blocking of the rolls when stacked and, particularly when packaged as a single adhesive tape roll, to sticking to the packaging material.To prevent these properties, so-called side plates are often used. These plates are coated with a non-adhesive coating (e.g., siliconized) that prevents the adhesive from sticking to the adhesive. These side plates are applied to the side surfaces of the adhesive tape rolls immediately after cutting. This ensures that the adhesive flow through the side plates (also called discs) is stopped, thus limiting the described blocking and sticking – if at all – to only small areas.

[0005] However, the adhesive tape is often applied without the protective side panels. Firstly, dirt and dust can then adhere to the sticky sides (which has the potential to damage the substrate being bonded), and secondly, if stored on its side for a long time, the roll can also stick to the surface. Both effects are undesirable. Furthermore, applying the side panels is a separate step and therefore a cost-intensive process.

[0006] Adhesive tape rolls whose side surfaces are provided with a passivating coating are already known from the state of the art.

[0007] For example, EP 3 819 347 A1 describes adhesive products in which the surface of the adhesive layer is functionalized, at least in some areas, resulting in a non-tackiness and / or a reduction in the adhesive strength of the adhesive layer, particularly at its edges. Due to the necessary adaptation of the functionalization to the material of the adhesive layer, such processes are not universally applicable, and complex machine conversion is required when the type of adhesive tape produced is changed.

[0008] Furthermore, such functionalized adhesive products are not yet fully convincing in terms of their storage stability (temperature stability, stability against humidity, stability against friction during transport). However, the requirements for such coatings are high: they must not lose their suitability for use under the conditions of possible transport, for example, by sea or in a heated construction vehicle, over a wide temperature range, at varying air humidity, and even under mechanical influences caused by transport, such as friction. Furthermore, the coating should not be too hard / brittle, as otherwise the unrolled adhesive tape might have sharp edges, which could lead to damage to the materials to be bonded, such as nonwovens or membranes.

[0009] In order to avoid the use of side windows and the associated manual work and to reduce or prevent the other disadvantages mentioned, the sticking and blocking of the adhesive tape rolls - even after storage and transport as well as during use - should be avoided as completely as possible with the help of an automatically applied, optimized layer on the side surface of the adhesive tape roll.

[0010] In addition, the resulting adhesive tape should not leave any threads behind when unrolled and should be easy to tear by hand. The adhesive tape roll should not stick to the surface or other materials during use, and no dirt and / or dust should accumulate on the side surfaces.

[0011] The invention is therefore based on the object of improving the performance properties of such adhesive tape rolls and the adhesive tapes resulting therefrom by means of a special lacquer layer on the side surfaces of the adhesive tape rolls.

[0012] Surprisingly, it has now been found that adhesive tape rolls that are provided with a lacquer layer that has cavities do not have the disadvantages mentioned and, in particular, do not tend to block or stick together even after prolonged storage, do not pick up dirt on the edges and the resulting adhesive tape has no sharp edges and is easy to tear by hand.

[0013] This advantageously makes it possible to dispense with side windows and / or intermediate layers when packaging the adhesive tape rolls according to the invention, which leads to a reduction in the use of labor and materials and thus in costs, and also to a minimization of waste, in particular plastic waste.

[0014] A first subject of the present invention is therefore a roll of adhesive tape comprising an adhesive tape wound onto itself to form a roll, wherein at least one of the side surfaces of the roll of adhesive tape is provided with a lacquer layer having cavities.

[0015] Further advantageous embodiments of the invention will become apparent from the following explanations, the drawings, the examples and the appended claims.

[0016] For the purposes of this invention, the general term "adhesive tape" encompasses all flat structures that exhibit self-adhesive properties on one or both sides. The adhesive tapes according to the invention can be designed with or without a carrier material.

[0017] Although not absolutely necessary, it has proven advantageous if the adhesive tape rolls according to the invention have a so-called roll core in the center. A roll core is preferably a cylinder which lies transversely to the winding direction of the adhesive tape and around which the adhesive tape is wound. A roll core preferably consists of diagonally wound cardboard or plastic. Preferred roll cores have an inner diameter of 28 to 51 mm, with 1 inch, 1.5 inches, 2 inches or 3 inches being preferred. The term “side surfaces” according to the invention refers to the surfaces of the adhesive tape roll which are perpendicular to the axis of rotation of the roll. In the modern production of adhesive tape rolls, cutting processes are often used to produce an adhesive tape roll which is of a size that the end user can handle after coating a wide master roll.In these cases, the side surfaces of the ready-to-use adhesive tape rolls are created along the cutting line and are accordingly also called “cut surfaces” or “cut edges”.

[0018] According to the invention, the “lacquer layer” is understood to mean the material that is present for edge passivation on the side surfaces of the ready-to-use adhesive tape roll.

[0019] Although there are no limits to the type of cavities contained in the lacquer layer according to the invention, it has proven advantageous if they are formed by lightweight fillers.

[0020] In a first advantageous embodiment, the cavities are formed by hollow spheres. The hollow spheres are characterized by the fact that they each have a surrounding edge layer made of a characteristic material that differs from the material of the paint layer. Examples of such hollow spheres are hollow metal spheres, such as hollow steel spheres, hollow glass spheres, hollow plastic spheres based, for example, on phenolic resins, epoxy resins, or polyesters, expanded hollow microspheres, and / or hollow ceramic spheres.

[0021] The hollow spheres are preferably completely surrounded by the lacquer layer. However, it can also happen - particularly in the upper edge region of the lacquer layer - that individual hollow spheres protrude from the lacquer layer and are no longer completely surrounded by it. Hollow spaces formed by expanded hollow microspheres are particularly preferred. This embodiment is characterized in particular by its simple production, since the hollow microspheres in non-expanded - and therefore expandable - form can be incorporated into a coating dispersion, which is then sprayed onto the side surface of the adhesive tape rolls. The smaller volume of the non-expanded hollow microspheres reduces nozzle abrasion; furthermore, it is advantageous that the coating can penetrate even smaller cavities and layers of the side edge of the adhesive tape roll, thus resulting in fewer defects in the lacquer layer.The conversion of the expandable hollow microspheres into the expanded form can occur during the drying process of the coating to form the coating layer according to the invention. Furthermore, the use of expanded hollow microspheres increases the flexibility of the coating layer.

[0022] Particularly preferred are expanded hollow microspheres, which can be formed by thermal expansion from the expandable hollow microspheres described below. Regarding the preferred embodiments, reference is therefore made to the further explanations at this point.

[0023] In a further advantageous embodiment, the cavities are formed by gas bubbles within the paint layer. Unlike hollow spheres, gas bubbles are characterized by being directly surrounded by the paint layer material and thus do not have a surrounding edge layer made of a different material. A preferred example is foam-like structures.

[0024] In the latter two variants, it has proven advantageous if the cavities in the lacquer layer are obtained by thermal treatment of a coating containing thermally expandable hollow microspheres and / or at least one thermally activatable blowing agent. In this embodiment, the applied coating is transformed into the lacquer layer according to the invention by the thermal treatment. Accordingly, the "coating" refers to the material applied to the side surface of the adhesive tape roll before the thermal treatment.

[0025] The expandable hollow microspheres according to the invention consist of a flexible, thermoplastic, polymeric shell and a core containing a liquid and / or a gas that expands when heated.

[0026] Preferably, the core material is an organic substance that has a lower boiling point than the softening temperature of the polymer shell. Examples of suitable core materials are propane, butane, pentane, isobutane, neopentane, and combinations thereof. Isobutane is a particularly preferred core material according to the invention.

[0027] The choice of thermoplastic resin for the polymer shell influences the temperature range of expansion as well as the mechanical properties of the resulting coating layer.

[0028] For example, acrylonitrile-containing resins can be used, in particular with an acrylonitrile content of at least 50 wt%, preferably at least 60 wt% and more preferably at least 70 wt%.

[0029] Other examples of suitable thermoplastic resins that can be used as a shell are

[0030] - Acrylic and methacrylic acid esters such as polyacrylate, acrylate-acrylonitrile copolymers and methacrylate-acrylic acid copolymers,

[0031] - polystyrene, styrene (meth) acrylate copolymers,

[0032] - Vinylidene chloride-containing polymers such as vinylidene chloride-methacrylate copolymers, vinylidene chloride-acrylonitrile copolymers, acrylonitrile-vinylidene chloride-methacrylonitrile-methylacrylate copolymers, and acrylonitrile-vinylidene chloride-methacrylonitrile-methylmethacrylate copolymers. Expanded hollow microspheres with a wall material made of (meth)acrylic acid ester copolymers, polystyrene, styrene(meth)acrylate copolymers, and, in particular, polyvinylidene chloride and copolymers of vinylidene chloride with acrylonitrile and / or (meth)acrylic acid esters have proven particularly advantageous.

[0033] Furthermore, it is advantageous if the materials of the expanded hollow microspheres and the other components of the paint coating are matched to one another in such a way that good adhesion of the paint to the spheres is ensured.

[0034] The expandable hollow microspheres preferably have, before the thermal treatment, a volume-weighted particle size distribution with a D(0.5) value of 5 to 30 pm, preferably of 6 to 25 pm (measured by laser diffraction, low angle light scattering).

[0035] During thermal expansion, the hollow microspheres increase their volume; it is preferred if the diameter of the hollow microspheres at least doubles, preferably at least triples, in particular at least quadruples during thermal expansion.

[0036] Depending on the nature of the core and shell materials of the hollow microspheres, they each exhibit a characteristic temperature range in which they expand. Expandable hollow microspheres with an expansion temperature range of 70 to 175°C, preferably 75 to 150°C, in particular 80 to 145°C, are advantageous for the purposes of the present invention.

[0037] Particularly preferred according to the invention are expandable hollow microspheres which

[0038] - under the trade name Expancel® by Nouryon,

[0039] - under the trade names Dualite® E and Dualite® U by Chase Corporation,

[0040] - by the company Crerax, - under the trade name CELLCOM® by the company KUMYANG or

[0041] - sold by KUREHA under the trade names KUREHA® Microspheres H series and S series. The expandable hollow microspheres sold by Nouryon under the trade name Expancel® are particularly preferred according to the invention.

[0042] The coatings according to the invention preferably contain the thermally expandable hollow microspheres in an amount of 1 to 10 wt.%, in particular 2 to 8 wt.%, very particularly preferably 3 to 7 wt.%, in each case calculated as the mass of the solids content based on the mass of the entire coating.

[0043] Particularly suitable as thermally activatable propellants are those propellants which release gases through thermal decomposition; examples of suitable thermally activatable propellants are azo compounds, hydrazide compounds, nitroso compounds and carbazide compounds, such as azobisisobutyronitrile, azodicarbonamide (ADCA), di-nitroso-pentamethylenetetramine, 4,4'-oxybis(benzenesulfonic acid hydrazide) (OBSH), azocyclohexylnitrile, azodiaminobenzene, benzene-1,3-sulfonylhydrazide, calcium azide, 4,4'-diphenyldisulfonylazide, diphenylsulfone-3,3'-disulfohydrazide, benzene-1,3-disulfohydrazide, trihydrazinotriazine, p-toluenesulfonylhydrazide and p-toluenesulfonylsemicarbazide.

[0044] According to the invention, blowing agents which are activated below 140 °C, such as azodicarbonamides, are particularly advantageous.

[0045] The thermally activatable blowing agents are contained in the coatings in an amount of 0.01 to 12.5 wt.%, in particular 1 to 8.5 wt.%.

[0046] It has proven advantageous if the cavities, in particular the lightweight fillers, in the paint layers have a volume-averaged particle size distribution with a D(0.5) value of 2 to 150 pm, preferably of 10 to 100 pm, very preferably of 20 to 60 pm (measured by means of laser diffraction, low angle light scattering).

[0047] Expanded hollow microspheres having a volume-average particle size distribution with a D(0.5) value of 2 to 150 pm, preferably of 10 to 100 pm, very preferably of 20 to 60 pm, are particularly advantageous in the context of the present invention.

[0048] Advantageously, the determination of the volume-averaged particle size distribution can be carried out according to the standard ISO 13320:2020-01.

[0049] The adhesive tape rolls according to the invention comprise an adhesive tape wound on itself.

[0050] In principle, the present invention is not subject to any restrictions regarding the adhesive tapes used. On the one hand, single-sided adhesive tapes, which are characterized by a carrier and a single-sided adhesive layer, can be passivated. On the other hand, passivation of double-sided adhesive tapes and so-called transfer adhesive tapes is also possible. Double-sided adhesive tapes are characterized by a carrier coated on both sides with an adhesive. A transfer adhesive tape is an adhesive tape that uses no carrier material, but only the adhesive itself.

[0051] For double-sided and transfer adhesive tapes, a so-called liner is essential. This separates the two consecutive layers of the roll from each other, as they would otherwise stick together. The liner consists of a carrier material which, for example, has a silicone coating that makes it very difficult for the adhesive to bond and thus easy to remove. Such a liner may also be required for single-sided adhesive tapes to prevent them from sticking to the back of the adhesive tape. In an advantageous embodiment of the present invention, the adhesive tape roll is characterized in that the adhesive tape comprises at least one carrier and at least one adhesive layer applied to the carrier.

[0052] The adhesive layer is preferably a pressure-sensitive adhesive (PSA). Although the pressure-sensitive adhesive can in principle be made from many different materials, it has proven advantageous according to the invention if the pressure-sensitive adhesive is based on acrylates and / or natural and / or synthetic rubber resins.

[0053] As acrylates, copolymers of (meth)acrylic acid and its esters having 1 to 25 C atoms, maleic, fumaric and / or itaconic acid and / or its esters, substituted (meth)acrylamides, maleic anhydride and other vinyl compounds, such as vinyl esters, in particular vinyl acetate, vinyl alcohol and / or vinyl ethers, are preferably used in the adhesive layers according to the invention.

[0054] Depending on the application, the acrylates are preferably used as acrylate base polymers and / or as UV-crosslinkable hotmelt acrylates and / or as dispersion acrylates and / or as solvent acrylates, whereby in all cases radiation-induced crosslinking can take place.

[0055] In an acrylate bulk polymer, acrylate monomers and / or oligomers are applied and then polymerized under UV initiation. It has proven advantageous if the acrylate bulk polymers are crosslinked to form the pressure-sensitive adhesive according to the invention. Conventional crosslinking methods can be used, for example by thermal activation, by irradiation, for example by UV radiation or electron beam (E-beam). Crosslinking by UV radiation is particularly preferred according to the invention. UV-crosslinkable hotmelt acrylates according to the invention are understood to be UV-crosslinkable low-molecular-weight acrylate polymers that are applied as a melt and crosslinked by UV radiation. It has proven advantageous if the UV-crosslinkable acrylate polymers either already contain a polymerized photoinitiator themselves or if a photoinitiator is added separately to the melt.Corresponding UV-crosslinkable low-molecular-weight acrylate polymers, which have proven to be particularly suitable, are commercially available from BASF, for example, under the name acResin® UV.

[0056] Preference may also be given to pressure-sensitive adhesives based on acrylate hotmelts, into which benzoin derivatives, such as benzoin acrylate or benzoin methacrylate, as well as corresponding acrylic or methacrylic esters, are optionally polymerized. Such benzoin derivatives are described in EP 0 578 151 A. The acrylate hotmelt-based adhesive can be UV-crosslinked. Other crosslinking methods are also possible, for example, electron beam crosslinking.

[0057] Dispersion acrylates, especially aqueous dispersion acrylates, have also proven suitable. In these cases, acrylate polymers are applied from a dispersion, and the dispersion medium is subsequently removed. Crosslinking can also be achieved with dispersion acrylates, for example, by adding thermally activated initiators, such as carbodiimide crosslinkers. Such dispersion acrylates are marketed commercially by BASF, for example, under the trade name Acronal®.

[0058] Solvent-based acrylates have also proven advantageous. In this case, acrylate polymers are applied dissolved in a solvent, especially in an organic solvent, and the solvent is subsequently removed. Crosslinking can also occur with solvent-based acrylates. UV-crosslinkable hotmelt acrylates and / or aqueous dispersion acrylates are particularly preferred according to the invention.

[0059] It has been found advantageous for synthetic rubber resins to be selected from ABA-type block copolymers, where block A is a derivative of a styrene monomer and block B is a derivative of an isoprene or butadiene monomer or their hydrogenated variants.

[0060] Furthermore, isobutene-isoprene block copolymers (butyl rubbers) have proven to be a preferred adhesive layer. Natural rubbers can also be used as adhesives in the adhesive tape rolls according to the invention.

[0061] In the context of the present invention, it is particularly advantageous if the adhesive layer

[0062] - an acrylate adhesive, in particular a UV-crosslinkable hotmelt acrylate, a dispersion acrylate, in particular an aqueous dispersion acrylate, a solvent acrylate and / or an acrylate mass polymer,

[0063] - a styrene-isoprene-styrene block copolymer (SIS),

[0064] - a styrene-butadiene-styrene block copolymer (SBS) and / or

[0065] - contains an isobutene-isoprene block copolymer (butyl rubber).

[0066] The adhesives can be produced and processed from solution, dispersion, or melt. Particular preference is given to producing the adhesive from the melt, with batch or continuous processes being particularly suitable. Continuous production of the pressure-sensitive adhesives using an extruder or as part of a continuous batch process is particularly advantageous. In a continuous batch process, at least two batches are operated side by side and used countercyclically to one another. The adhesives produced in this way can be applied to the carrier using generally known processes. When processed from the melt, this can be application via a die or calender. When processed from the solution, coatings using doctor blades, knives, or nozzles are known, to name just a few.

[0067] If the adhesive is applied as a reactive system, it is subsequently reacted - for example, UV-induced - to obtain the adhesive layer according to the invention.

[0068] The technical focus of the present invention is on adhesive layers made of UV-crosslinkable hot-melt acrylates, although other systems, such as those based on synthetic rubber and / or the application of aqueous dispersions, can also benefit from the advantages of the present invention. Such systems are used, for example, in adhesive tapes for roofing membranes and adhesive tapes that include an aluminum layer in the carrier.

[0069] It is also advantageous if the adhesive is applied to the carrier with a basis weight in the range of 100 to 350 g / m 2 , preferably in the range of 150 to 300g / m 2 is applied.

[0070] A particular advantage of the present invention is that the lacquer layer can be applied universally, i.e., regardless of the nature of the carrier. In this way, adhesive tape rolls with different carriers or different adhesive layers can be coated with the lacquer layer according to the invention on one apparatus without the need for complex retooling.

[0071] It is also advantageous if the adhesive tape rolls have a textile carrier, in particular a nonwoven, a stitched nonwoven or a woven fabric, or a paper or film carrier. A second subject of the present invention is a method for producing a passivated adhesive tape roll, in which at least one side surface of the adhesive tape roll

[0072] - in a first step, it is provided with a coating containing thermally expandable hollow microspheres and / or at least one thermally activatable blowing agent, and

[0073] - the coating is thermally treated in a second step so that a lacquer layer with cavities forms on the treated side surface.

[0074] With regard to the details of this subject matter of the present invention, what has already been said regarding the other subject matters applies mutatis mutandis.

[0075] With regard to the process technology to be used in the first step of the process according to the invention, the following processes can be used:

[0076] - Painting, for example manually by brush, roller, brush or sponge,

[0077] - Spraying processes, for example with a spray bottle, pressure nozzle, airbrush, ultrasonic atomizer, etc., preferably in an automated process,

[0078] - Curtain coating application, i.e. a curtain coating, which is particularly advantageous with regard to the possibility of collecting the medium to be applied,

[0079] - Application between two rollers under pressure,

[0080] - all common coating processes such as blade coating, application with comma bar, doctor blade and indirect coating via several rollers, etc., - gravure printing processes, in particular indirect gravure printing processes such as pad printing,

[0081] - Plasma processes, such as reactive plasma coating, for example PECVD.

[0082] According to the invention, applying the coating using a spray technique has proven particularly advantageous. Two different embodiments have proven advantageous within the meaning of the invention.

[0083] In a first embodiment (static system), a static spray nozzle and an apparatus are used to rotate the adhesive tape roll within the spray area. The adhesive tape roll is preferably rotated vertically, i.e., around the axis of the roll center, by means of a roller drive. Wide-jet nozzles or painting nozzles with shaping air control are preferred static spray nozzles according to the invention. Painting nozzles with shaping air control, in which the shaping air is composed of a wide and a round jet, are particularly advantageous.

[0084] In a second preferred embodiment (dynamic system), the adhesive tape roll is placed on a turntable, and the coating is then applied using a movable nozzle. A round-jet head is a preferred movable nozzle according to the invention.

[0085] However, other forms of application are also conceivable, for example by a robot.

[0086] The thermal treatment carried out in the second step of the process according to the invention can be carried out, for example, in an oven and / or in a hot air zone and / or in a reaction zone and / or by means of an IR radiator. Thermal treatment in an oven and / or by means of an IR radiator is particularly preferred according to the invention.

[0087] In order to activate the thermally activatable components in the coating on the one hand and to expose the adhesive tape roll to as little heat as possible on the other, it has proven advantageous if the thermal treatment is carried out until the surface temperature of the coating applied to the side surface has reached a temperature of 100°C to 150°C, in particular a temperature of 120°C to 140°C, and very particularly preferably a temperature of 120°C to 130°C, for a period of 2 seconds to 20 seconds, preferably 4 seconds to 10 seconds, measured in each case using a non-contact IR thermometer with a measuring distance of 20 cm. According to the invention, it is preferred if the IR thermometer has a measuring distance to the measuring spot size ratio (distance-to-spot ratio or D:S) of 11:1.

[0088] An example of a contactless IR thermometer is the commercially available Scantemp® 410 device from TFA.

[0089] Achieving a surface temperature of 130 °C for a period of 3 seconds to 8 seconds has proven to be particularly advantageous according to the invention.

[0090] It is also advantageous if the coating on the side surfaces of the adhesive tape roll according to the invention is applied with an application weight in the range of 8 to 300 g / m 2 , preferably in the range of 10 to 150 g / m 2 The basis weight of the lacquer layer resulting from the process according to the invention, i.e. after the thermal treatment, is preferably 2 to 200 g / cm 2 , preferably 7 to 100 g / cm 2

[0091] In addition to the components essential to the invention, the coating may contain other conventional components. It has proven advantageous according to the invention if the coating applied in the first step is water-based and / or applied as a hot melt. A water-based coating has proven particularly advantageous.

[0092] In addition to the thermally expandable hollow microspheres and / or the at least one thermally activatable blowing agent, the coating applied in the first step of the process according to the invention further contains

[0093] - at least one anchoring aid and / or

[0094] - at least one rheology modifier.

[0095] According to the invention, an “anchoring aid” is understood to mean a compound which helps to fix the lacquer layer on the side surface of the adhesive tape roll.

[0096] Preferred anchoring aids according to the invention are selected from crosslinked acrylate dispersions, in particular aqueous acrylate dispersions, core-shell acrylates, acrylic resins, polyurethane dispersions, and / or natural latex dispersions. Solvent-containing systems or reactive systems—for example, UV-induced—can be used. Other suitable reactive systems include, for example, 2-component systems based on epoxides and / or polyurethanes, room-temperature-curing silicones (RTV), silanes / silane-modified polymers, and moisture- and / or high-temperature-curing silicones (HTV).

[0097] According to the invention, a “rheology modifier” is understood to mean a compound which improves the rheology profile of the - preferably water-based - coating and / or ensures the most homogeneous distribution possible of the thermally activatable components within the coating.

[0098] Rheology modifiers selected from the group of associative thickeners, in particular hydrophobically modified polyacrylates, hydrophobically modified cellulose ethers, hydrophobically modified polyacrylamides, hydrophobically modified polyethers, phyllosilicates such as montmorillonites or bentonites, fumed silicas, and associative polyurethane thickeners, have demonstrated a particularly beneficial effect on coating stabilization. Phyllosilicates and polyurethane thickeners are particularly suitable in this regard.

[0099] It has further proven particularly advantageous, especially if the coating is sprayed onto the side surface of the adhesive tape roll in the first step and / or is water-based, if the coating has a viscosity in the range of 100 to 1500 mPas, in particular in the range of 500 to 1200 mPas, before spraying (determined by means of a Brookfield viscometer, spindle RV3, 50 rpm, 25°C).

[0100] The adhesive tape rolls according to the invention are offered for sale in various packaging forms.

[0101] This allows the adhesive tape rolls to be packaged in larger containers for major customers. Several rolls are stacked on top of each other with their respective sides, and several of these stacks of rolls are packed side by side in a carton. The side panels and / or interlayers described above can be arranged between the individual sides of the adjacent rolls in such a stack.

[0102] Due to the surprising advantages of the present invention, it is also possible to dispense with the separating side panels and to arrange the side surfaces of the adhesive tape rolls provided with the lacquer layer directly on top of one another or only separated from one another by an intermediate layer.

[0103] A third subject matter of the present invention is accordingly a sales unit comprising a plurality of adhesive tape rolls according to the invention stacked on top of one another, wherein the side surfaces of two adjacent adhesive tape rolls are in direct contact with one another or are merely separated from one another by an intermediate layer, and at least one of the side surfaces in direct contact with one another or in contact with an intermediate layer has a lacquer layer according to the invention in the contact area with the other roll or with the intermediate layer.

[0104] Particularly advantageous are sales units comprising two or more rolls of adhesive tape stacked on top of one another, the rolls of adhesive tape being in direct contact with one another via their respective side surfaces, at least one of the side surfaces in contact with one another having a lacquer layer according to the invention in the contact area with the other roll.

[0105] Alternatively, the adhesive tape rolls according to the invention are also offered in individual packaging for the end customer, for example, in hardware stores and corresponding online platforms. In this embodiment, too, the lacquer coating according to the invention reduces the stickiness of the side surfaces of the adhesive tape roll, so that the conventional side panels can be dispensed with in this packaging form as well, without the packaging components, in particular the cardboard packaging and the shrink film used, sticking to the side surface of the adhesive tape roll.

[0106] With regard to the details of this subject matter of the present invention, what has already been said regarding the other subject matters applies mutatis mutandis.

[0107] It shows

[0108] Fig. 1 is a perspective view of an adhesive tape roll according to the invention with a lacquer layer

[0109] Fig. 2 a schematic exploded view of a stack of four adhesive tape rolls

[0110] Fig. 3 is a schematic exploded view of a stack of four adhesive tape rolls with intermediate layers in between. Fig. 1 schematically shows an adhesive tape roll 1 which has been provided with a lacquer layer 2 according to the invention on one of its two side surfaces 3. According to the invention, it is particularly preferred if both side surfaces 3 of the adhesive tape rolls 1 are provided with a lacquer layer 2 according to the invention.

[0111] Fig. 2 shows, by means of an exploded view, the orientation in which four adhesive tape rolls 1 are stacked on top of one another, so that the adhesive tape rolls 1 are in direct contact with each other via their respective side surfaces 3. The lacquer layer 2 according to the invention is not shown in the drawing.

[0112] Fig. 3 shows, by means of an exploded view, the orientation in which four adhesive tape rolls 1 are stacked with intermediate layers 4 in between, so that the side surfaces 3 of two adjacent adhesive tape rolls 1 are separated from each other only by an intermediate layer 4. The lacquer layer 2 according to the invention is not shown in the drawing.

[0113] Within the scope of the activities underlying this invention, it was shown that the use of a lacquer layer 2 having cavities on at least one side surface 3 of an adhesive tape roll 1 passivates the latter at its edges and significantly improves its performance properties.

[0114] It has further been found that the use of a lacquer layer 2 having cavities on at least one side surface 3) of an adhesive tape roll 1 results in the adhesive tape being easy to unwind and the adhesive it contains being less likely to pull threads.

[0115] Furthermore, the use of a lacquer layer 2 having cavities on at least one side surface 3 of an adhesive tape roll 1 enables the edge profile of the unwound adhesive tape to be rounded, so that the resulting adhesive tape has fewer sharp edges. This makes the resulting adhesive tape easier to process without the user running the risk of damaging themselves or the materials to be bonded. The lacquer layer 2 according to the invention is further characterized by the fact that it easily breaks apart when the adhesive tape is unwound from the roll, thus allowing the adhesive tape to be unwound from the roll without any problems.

[0116] A fourth subject of the present invention is accordingly the use of a lacquer layer 2, which has cavities, on at least one side surface 3 of an adhesive tape roll 1 to improve the handling of the adhesive tape roll 1, in particular for

[0117] - Passivation of the side surfaces 3 of the adhesive tape roll 1 ,

[0118] - Reduction of pulling threads when unwinding the adhesive tape roll 1 and / or

[0119] - Avoidance of sharp edges of the adhesive tape after unwinding the adhesive tape roll 1.

[0120] With regard to the details of this subject matter of the present invention, what has already been said regarding the other subject matters applies mutatis mutandis.

[0121] The invention is not limited to the illustrated and described embodiments, but also encompasses all equivalent embodiments within the meaning of the invention. It is expressly emphasized that the embodiments are not limited to all features in combination; rather, each individual feature can also have an inventive significance in isolation from all other features. Furthermore, the invention is not yet limited to the combination of features defined in claim 1, but can also be defined by any other combination of specific features of all the individual features disclosed overall. This means that, in principle, practically every individual feature of claim 1 can be omitted or replaced by at least one individual feature disclosed elsewhere in the application.

[0122] All quantities used in the examples are in percent by weight unless otherwise stated.

[0123] 1. Dispersion formulations

[0124] The raw materials mentioned were mixed in an ED mixing beaker with a capacity of 1900 ml using an electronic laboratory stirrer (Hei-TORQUE 200) with a propeller stirrer with a ring.

[0125] Batches of approximately 1000 g were prepared. First, WorleeCryl® 7462 was added, followed by the demineralized water. WorleeAdd® 6226 was then added while gently stirring at approximately 200 rpm, and the mixture was stirred for another 5 minutes.

[0126] The rheology modifier was then added to formulation E1, and the speed was increased to 1000 rpm. The mixture was then stirred for another 10 minutes. The filler (Expancel® 031 WU40) was then added in portions over a period of 15 minutes, and the mixture was stirred for another 30 minutes. After sieving the resulting formulations V1 and E1 through a 125 pm nylon sieve (AquaDrop 125, Schuller Eh'klar GmbH), homogeneous dispersions were obtained.

[0127] The paint layer 2 was applied using a static spray nozzle with shaped air control (shaping air composed of a wide and a circular jet) to the side surface 3 of a roll of adhesive tape 1 moving vertically in the spray mist. The nozzle was selected to ensure good coverage of the side surfaces 3 of the respective rolls of adhesive tape 1 (overspray was permitted). Each roll of adhesive tape 1 was exposed to the paint mist for 3 revolutions at a constant rotation speed. The dispersions V1 (comparison) and E1 (according to the invention) were each sprayed onto both side surfaces 3 of 8 rolls of adhesive tape 1 of the following types:

[0128] Adhesive tape roll A

[0129] - Backing made of PP spunbond, basis weight 60g / m 2

[0130] - One-sided adhesive application of a UV-cured hotmelt acrylate with an application weight of 200g / m 2

[0131] - Cover made of siliconized paper (liner)

[0132] Adhesive tape roll B

[0133] - PE paper backing, grammage 120g / m 2

[0134] - One-sided adhesive application of a UV-cured hotmelt acrylate with an application weight of 200g / m 2

[0135] - Cover made of siliconized paper (liner)

[0136] The coated rolls were then dried using a hot air dryer, with the dryer being moved in a circle over the rolls until a surface temperature of 130 °C was reached on the coated side surfaces 3 for a period of 3 to 5 seconds (measured using a commercial, non-contact IR thermometer (Scantemp 410 from TFA) at a distance of 20 cm). After application and drying, four identical adhesive tape rolls of type A and type B, one without and one with intermediate layers 4 (LDPE film siliconized on one side with a thickness of 200 μm), were stacked on top of each other to form a roll stack so that their respective side surfaces 3 were in contact with each other and with the intermediate layer 4. The resulting roll stacks, each consisting of four adhesive tape rolls 1, were dried for 8 weeks at a temperature of 40 °C and a relative humidity of 100 °C.Humidity of 80% in a climate cabinet (model CTS C-40 / 100, Clima Temperature Systems).

[0137] After storage, the samples were tested for interlocking. For this purpose, the adhesive tape rolls 1 were subjected to manual force in a vertical direction (at an angle of 90° to the side surface 3) to achieve, if possible, separation of the rolls from each other or from the release liner.

[0138] The following separation behavior was observed:

[0139] While the rolls treated with the coating layer V1 could not be separated non-destructively using manual force, the rolls treated with the coating according to the invention showed significantly improved separability – both from each other and from the intermediate layer 4. The rolls treated with the formulation E1 according to the invention fell apart as soon as the rolls were lifted. Accordingly, in this case, the weight of the roll itself (700-1200 g, corresponding to a force of approximately 7-12 N) caused the rolls to separate from each other and from the intermediate layer 4. 2. List of raw materials used

[0140] WorleeCryl® 7462 aqueous pure acrylic dispersion containing ethoxylated disodium C10-C16 fatty alcohol succinate and benzoisothiazolone derivatives, approx. 55% solids content in water, Worlee

[0141] Expancel® 031 WUF 40 expandable hollow microspheres containing isobutane, shell made of copolymer based on acrylic-added monomers, average particle size D(0.5): 10-16 pm; onset of expansion at approx.

[0142] 80 - 95 °C; Tmax: 118 - 133 °C; approx. 74 - 79% solids content in water, Nouryon Pulp and Performance Chemicals AB

[0143] WorleeAdd® 6226 defoamer based on a siloxane mixture containing decamethylcyclopentasiloxane, Worlee

[0144] Rheobyk®-H 7625 VF associative thickener, aqueous solution of a hydrophobically modified, ethoxylated urethane thickener (HEUR), Byk-Chemie GmbH

[0145] List of reference symbols: Adhesive tape roll Lacquer layer applied to a side surface of the adhesive tape roll Side surface of an adhesive tape roll Intermediate layer

Claims

Patent claims 1. Adhesive tape roll (1) comprising an adhesive tape wound onto itself to form a roll, wherein at least one of the side surfaces (3) of the adhesive tape roll (1) is provided with a lacquer layer (2), characterized in that the lacquer layer (2) has cavities.

2. Adhesive tape roll (1) according to claim 1, characterized in that the cavities are formed by lightweight fillers, in particular by hollow metal spheres, hollow glass spheres, hollow plastic spheres, expanded hollow micro spheres and / or hollow ceramic spheres.

3. Adhesive tape roll (1) according to claim 2, characterized in that the cavities are formed by expanded hollow microspheres.

4. Adhesive tape roll (1) according to one of claims 1 to 3, characterized in that the cavities are obtained by thermal treatment of a coating which contains thermally expandable hollow microspheres and / or at least one thermally activatable blowing agent.

5. Adhesive tape roll (1) according to one of claims 1 to 4, characterized in that the cavities have a volume-averaged particle size distribution with a D(0.5) value of 2 to 150 pm, preferably of 10 to 100 pm, very preferably of 20 to 60 pm.

6. Adhesive tape roll (1) according to one of claims 1 to 5, characterized in that the adhesive tape comprises at least one carrier and at least one adhesive layer applied to the carrier.

7. Adhesive tape roll (1) according to claim 6, characterized in that the adhesive layer comprises an acrylate adhesive, in particular a UV-crosslinkable hotmelt acrylate, a dispersion acrylate, in particular an aqueous dispersion acrylate, a solvent acrylate and / or a Acrylate mass polymer, a styrene-isoprene-styrene block copolymer (SIS), a styrene-butadiene-styrene block copolymer (SBS) and / or an isobutene-isoprene block copolymer (butyl rubber).

8. Adhesive tape roll (1) according to one of claims 6 to 7, characterized in that the basis weight of the at least one adhesive layer is in the range from 100 to 350 g / m 2 , preferably in the range of 150 to 300 g / m 2 lies 9. Adhesive tape roll (1) according to one of claims 6 to 8, characterized in that the carrier is a textile carrier, in particular a nonwoven, a stitched nonwoven or a woven fabric, and / or a paper or film carrier.

10. A method for producing a passivated adhesive tape roll (1), characterized in that at least one side surface (3) of the adhesive tape roll (1) - in a first step, it is provided with a coating containing thermally expandable hollow microspheres and / or at least one thermally activatable blowing agent, and - the coating is thermally treated in a second step so that a lacquer layer (2) with cavities is formed on the treated side surface (3).

11. A method according to claim 10, characterized in that the coating applied in the first step is water-based.

12. The method according to any one of claims 9 to 11, characterized in that the thermal treatment is carried out until the surface temperature of the coating applied to the side surface (3) has reached, for a period of 2 seconds to 20 seconds, preferably 4 seconds to 10 seconds, in the range from 100 °C to 150 °C, in particular in the range from 120 °C to 140 °C, very particularly preferably in the range from 120 °C to 130 °C, in each case measured by means of a contactless IR thermometer with a measuring distance of 20 cm.

13. Method according to one of claims 9 to 12, characterized in that the coating further contains a) at least one anchoring aid, and / or b) at least one rheology modifier.

14. The method according to claim 13, characterized in that the anchoring aid is selected from the group of crosslinked acrylate dispersions, in particular aqueous acrylate dispersions, core-shell acrylates, acrylic resins, polyurethane dispersions and / or natural latex dispersions.

15. The method according to claim 13 or 14, characterized in that the rheology modifier is selected from the group of associative thickeners, in particular hydrophobically modified polyacrylates, hydrophobically modified cellulose ethers, hydrophobically modified polyacrylamides, hydrophobically modified polyethers, phyllosilicates and associative polyurethane thickeners.

16. Sales unit, comprising several stacked adhesive tape rolls (1) according to one of claims 1 to 9, characterized in that the side surfaces (3) of two adjacent adhesive tape rolls (1) are in direct contact with one another or are only separated from one another by an intermediate layer (4), wherein at least one of the side surfaces (3) in direct contact with one another or with the intermediate layer (4) has a lacquer layer (2) according to one of claims 1 to 9 in the contact area with the other roll or the intermediate layer (4).

17. Use of a lacquer layer (2) having cavities on at least one side surface (3) of an adhesive tape roll (1) to improve the handling of the adhesive tape roll (1), in particular for - passivation of the side surface (3) of the adhesive tape roll (1), - Reduction of pulling of threads when unwinding the adhesive tape roll (1 ) and / or - Avoidance of sharp edges of the adhesive tape after unwinding the adhesive tape roll (1 ).

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