Reactive adhesive tape

Abstract

The utility model relates to a reactive curing adhesive tape, a method for manufacturing the reactive curing adhesive tape with a passivated side edge and application of the reactive curing adhesive tape. The reactive curable adhesive tape has a width corresponding to the range of the adhesive tape in the y-direction, and has a first outer edge and a second outer edge in the y-direction, and comprises at least one layer of a reactive curable adhesive comprising a reactive component wherein the curing is carried out by a chemical conversion of the reactive component, the adhesive layer has a first outer edge and a second outer edge, and is characterized in that the adhesive layer has an edge region and an intermediate region arranged between the edge regions in the y-direction at the first outer edge and the second outer edge, the edge regions being optically different from the intermediate region.

Description

Technical Field

[0001] The present utility model relates to a reactive curable tape, a method for manufacturing a reactive curable tape for side edge passivation, and the use of a reactive curable tape. Background Art

[0002] Reactive curable, especially room temperature curable (e.g., based on the polymerization of acrylate monomers) pressure-sensitive tapes have been developed for several years and have reached a high level of maturity.

[0003] For example, EP 3757183 A1 discloses a pressure-sensitive adhesive reactive adhesive comprising (a) at least one reactive monomer or reactive resin, (b) an initiator, especially a free radical initiator, and (c) a photo-redox catalyst, which can be cured by irradiation with UV light.

[0004] DE 10 2021 125429A1 also discloses a photo-curable reactive pressure-sensitive adhesive film comprising (a) at least one reactive monomer or reactive resin, (b) an initiator, (c) a photo-redox catalyst, (d) a polymer formed from monomers including N-vinyl compounds, and (e) a film-forming polymer.

[0005] EP 4242277A1 discloses a UV-curable adhesive based on polymerizable epoxy compounds, which is cationically polymerized by the activation of a cationic photoinitiator.

[0006] Unlike liquid reactive adhesives, reactive curable (or simply "reactive") tapes must have a certain degree of cohesion before activation, whereby they are pressure-sensitive adhesive. It has been shown here that it is challenging to balance sufficient cohesion to produce a good pressure-sensitive adhesive state before activation and high bond strength after activation. This is due to the opposite effects of changes in cohesion on the properties in the uncured state and the bond strength after activation. In the prior art, there are many indications on how to intervene in the formulation of reactive pressure-sensitive adhesive films to improve bleed-out (cold flow) performance and still achieve high bond strength.

[0007] WO 2017117163 A1 describes a method in which a slurry is first prepared and then crosslinked and polymerized at a certain wavelength after coating, but the curing reaction of the second reactive component is not triggered. This only occurs when the tape is applied by irradiation with a second wavelength.

[0008] US 9109142 B2 discloses specific graft polymers aimed at reducing bleed-out.

[0009] US 11377576 B2 discloses that specific film-forming polymers reduce exudation because the epoxides are "retained".

[0010] WO 2023037185 A1 discloses methacrylate block copolymers aimed at reducing exudation.

[0011] However, in all cases, the formulation is disturbed, thereby having a negative impact on the properties in the cured state.

[0012] Therefore, there remains a problem that tapes or tape rolls designed for high adhesion strength have undesired cold flow of the adhesive before application and curing of the corresponding adhesive. This can in particular lead to lateral (transverse) overflow of the adhesive from the tape or tape roll, making storage and transportation quite difficult. SUMMARY OF THE INVENTION

[0013] Therefore, the object of the present utility model is to provide a tape that can be reactively cured, which does not show any overflow of the adhesive in the unbonded state and still has optimal adhesion strength after bonding.

[0014] The object is achieved according to the present utility model by a tape as defined in the present utility model.

[0015] The tape according to the present utility model has a width corresponding to the extension (dimension, elongation) of the tape in the y direction, and has a first outer edge and a second outer edge in the y direction, and comprises at least one layer of a reactively curable adhesive comprising reactive components, wherein curing is carried out by chemical conversion of the reactive components, and is characterized in that the adhesive layer has an edge region at each of the first outer edge and the second outer edge in the y direction and an intermediate region arranged between the edge regions, wherein the chemical conversion of the reactive components of the adhesive in the edge regions takes place in each case to at least 30% and to a higher degree than in the intermediate region, and wherein each edge region has a width in the y direction greater than 200 μm.

[0016] Since the adhesives in the edge regions each have a higher degree of chemical conversion of the reactive components than the intermediate region, cold flow of the adhesive in the edge regions is inhibited and undesired overflow of the adhesive on the outer edges or side edges is avoided. At the same time, the adhesive can still be formulated as a reactively curable adhesive, so that optimal adhesion strength is achieved for the corresponding application without being adversely affected by altered or additional components.

[0017] Preferably, the chemical conversion in the intermediate region does not occur at all or only to a very small extent and thus preferably to an extent of 0 to 10%, particularly preferably 0 to 5%, especially 0%. Therefore, the adhesive in the intermediate region of the tape according to the present utility model remains uncured for subsequent applications and curing of the bond. In particular, the intermediate region has not been subjected to any treatment, especially irradiation.

[0018] Preferably, the chemical conversion of the reactive components of the adhesive in the edge regions each occurs to an extent of at least 50%, particularly preferably at least 60%, very preferably at least 70%, further preferably at least 75%, further particularly preferably at least 80% and up to 100%. Here, the conversion continues over time. An edge region having, for example, a conversion rate of at least 50% after irradiation may have a conversion rate of 80% after one day, for example.

[0019] Therefore, according to the present utility model, it is crucial only that the conversion in the edge regions occurs to an extent of at least 30% or according to a further preferred extent, so as to avoid the overflow of the adhesive on the outer edges.

[0020] In particular and preferably, the chemical conversion of the reactive components of the adhesive occurs in the edge regions in each case to an extent such that no adhesive overflows laterally from the tape. Here, the viscosity of the adhesive in the edge regions increases compared to the intermediate region.

[0021] The degree of chemical conversion is determined particularly within the scope of the present utility model by a suitable spectroscopic method by which the reactants can be determined qualitatively and quantitatively by comparison with reference documents. A person skilled in the art can identify the reactants suitable for the corresponding reactive chemistry and select the corresponding method for verification. A suitable and preferred method within the scope of the present utility model is ATR-FTIR (attenuated total reflection (ATR); Fourier transform infrared spectroscopy (FTIR)), as described below. This method is particularly suitable for determining the conversion rate of cationic polymerization involving epoxy compounds and radical polymerization of acrylates.

[0022] All embodiments of this specification are applicable to the tape according to the present utility model, the method for manufacturing the tape according to the present utility model, and the use of the tape according to the present utility model.

[0023] The present utility model also includes all features as any preferred technical solutions. In addition, the present utility model includes the combination of each feature with each other, and in this case also includes different preferred levels. Therefore, the present utility model also includes, for example, the combination of a first feature called "preferred" and a second feature called "particularly preferred". Here, the objects also specified within the scope of the "embodiment" also include different preferred levels.

[0024] The present utility model relates to a tape. The tape according to the present utility model has a width corresponding to the extension of the tape in the y direction and has a first outer edge and a second outer edge in the y direction.

[0025] In principle, the tape can exist in any manufacturing form, and a tape roll is preferred.

[0026] The tape, especially in the form of a web, can be manufactured here both in the form of a roll (i.e., wound on itself in the form of an Archimedean spiral) and obtained as an adhesive strip, for example, in the form of a blank or a die-cut part.

[0027] A web should be understood to mean an object whose length (extension in the x direction) is many times its width (extension in the y direction) and whose width is formed to be substantially the same along the entire length.

[0028] However, the present utility model should not be limited to the fact that the length in the x direction is greater than the width in the y direction. Therefore, for example, it also includes the square blanks of the present utility model.

[0029] Within the scope of the present utility model, the definition of the y direction is only used to describe the outer edges opposite to each other in one direction, at which the adhesive has other properties different from the rest of the tape, the intermediate region, so that no adhesive overflows from the tape due to cold flow (exudation).

[0030] Therefore, the general term "tape", and its synonym also called "adhesive strip", includes all flat structures in the sense of the present utility model, such as foils or foil segments extending two-dimensionally, tapes with an extended length and a limited width, tape segments, etc., and finally also includes die-cut parts or labels.

[0031] The preferred shapes of the blanks, die-cut parts, and labels are rectangles.

[0032] Preferably, the tape according to the present utility model exists in the form of a tape roll, where the y direction corresponds to the axial direction of the tape roll. Then, the longitudinal extension corresponds to the x direction or the circumferential direction.

[0033] In particular, the tape roll has the following advantages: there is no or practically no outer edge on which the adhesive can pass outwards in the x direction.

[0034] In addition to the longitudinal extension (x direction) and the width extension (y direction), the tape also has a thickness extending perpendicular to the two extensions (z direction), where the width extension and the longitudinal extension are many times larger than the thickness. The thickness is as uniform as possible over the entire surface extension determined by the length and width of the tape, and preferably exactly the same within the tolerance range.

[0035] The described embodiments are similarly applied to the carrier layer, which forms a layer in the x- and y-directions as a component of the tape according to some preferred embodiments.

[0036] It is to be understood that the individual layers are arranged one above the other in the z-direction, and in the form of a roll the z-direction is the radial direction.

[0037] At the outer edge, the adhesive layers each have an edge region. The edge region preferably extends substantially parallel to the circumferential direction of the tape roll, and in particular in the case of a rectangular tape, preferably has the shape of a strip which has a length in the x-direction (which corresponds in the case of a tape roll to the length of the tape wound on the tape roll) and a width in the y-direction (which represents a part of the width of the tape). Thus, within the scope of the present invention, the edge region can in particular be referred to as an edge strip.

[0038] According to the present invention, each edge region has a width in the y-direction of more than 200 μm.

[0039] Preferably, each edge region has a width in the y-direction of more than 200 μm and at most 800 μm, especially in the case of cationic polymerization during the curing of a reactive curable adhesive.

[0040] According to an advantageous embodiment, each edge region has a width in the y-direction of from 250 μm to 750 μm, especially from 300 μm to 600 μm.

[0041] The edge region is in particular and preferably optically distinguishable from the intermediate region. This is due to the different degrees of chemical conversion required by the present invention.

[0042] The optical distinguishability can here be caused by a turbidity and / or a color change during the chemical conversion. The color change is indicated in particular by the presence of one or more light indicators. These can be, for example, color indicators which change color when the pH value changes, or UV indicators which change their absorption spectrum due to UV light.

[0043] The optical differentiation is carried out here in particular by the human eye or, if necessary, by suitable spectroscopic methods.

[0044] Thus, one aspect of the present invention also provides a reactive curable tape which has a width corresponding to the extent of the tape in the y-direction, and has a first outer edge and a second outer edge in the y-direction, and comprises at least one layer of a reactive curable adhesive comprising reactive components, wherein the curing takes place by chemical conversion of the reactive components, wherein the adhesive layer each has an edge region at the first and second outer edges in the y-direction and an intermediate region arranged between the edge regions, and wherein the edge region is optically different from the intermediate region.

[0045] In another aspect of the present utility model, the edge region differs from the middle region in terms of different colors and / or different turbidity.

[0046] In another aspect of the present utility model, the edge region differs from the middle region in terms of a higher viscosity, which is particularly caused by a higher degree of chemical conversion in the edge region. Here, each of the edge regions has a higher viscosity than the middle region.

[0047] According to the present utility model, it is a reactively curable tape, which correspondingly includes at least one layer of a reactively curable adhesive, wherein the reactively curable adhesive includes reactive components for the purpose of reactive curing, and the curing is carried out through the chemical conversion of the reactive components.

[0048] Such a reactive adhesive layer as a component of the reactively curable tape is known to those skilled in the art.

[0049] Therefore, "reactively curable adhesive" within the scope of the present utility model should be understood to refer to an adhesive that cures through the chemical reaction of at least one correspondingly included reactive component, thereby producing an adhesive bond.

[0050] Within the scope of the present utility model, such an adhesive is also referred to as a "reactive adhesive".

[0051] The terms "reactively curable tape" and "reactive tape" are used synonymously within the scope of the present utility model. This similarly applies to adhesives and adhesive layers.

[0052] Preferably, the reactively curable tape or the corresponding reactive adhesive according to the present utility model functions as a structural adhesive or a semi-structural adhesive after curing.

[0053] According to DIN EN 923:2006-01, structural adhesives are significantly suitable for manufacturing load-bearing structures, where the adhesive bond can withstand a high percentage of the maximum breaking force for a long time without failure (as defined by ASTM: "bonding agents used for transferring required loads between adherends exposed to service environments typical for the structure involved"). Therefore, it is an adhesive for chemically and physically highly stressed bonding, which helps to strengthen the tape in the cured state.

[0054] The term “(semi-)structural adhesive” includes “semi-structural adhesives” and “structural adhesives”. A “semi-structural adhesive” means a cured adhesive having a tensile shear strength of at least 1.0 MPa and preferably at least 1.5 MPa (in each case on steel) in a tensile shear test. A “structural adhesive” means a cured adhesive having a particularly high tensile shear strength and having a tensile shear strength of at least 5 MPa, preferably at least 7 MPa and particularly preferably at least 10 MPa (in each case on steel) in a tensile shear test.

[0055] The chemical reaction occurs particularly after activation, for example by heat, moisture, plasma or particularly by irradiation (radiation) activation.

[0056] Within the scope of the present utility model, preferred are reactive curable tapes, wherein the curing is carried out by activating a chemical reaction or chemical transformation by means of irradiation, particularly by means of light having a wavelength in the visible range of the electromagnetic spectrum or by means of UV light.

[0057] In principle, the reactive curable adhesive can be any reactive curable adhesive known to those skilled in the art.

[0058] As understood by those skilled in the art, the components defined within the scope of the present utility model are used as “one or more” in each case. The term “one or more” herein refers to the chemical nature of the corresponding compounds in the manner of industry practice, rather than the amount of substance. For example, a curable adhesive as a polymerizable epoxy compound may include only cyclohexylmethyl-3’,4’-epoxycyclohexanecarboxylate, which means that the curable adhesive includes a plurality of corresponding molecules.

[0059] In the manner of industry standards, the mass fraction is expressed herein as the combined mass fraction of one or more components, whereby the mass fractions of the correspondingly formed components together meet the corresponding standards, where, in the absence of other information, in each case, the mass of the curable adhesive is the reference system.

[0060] Within the scope of the present utility model, unless otherwise specified, information on the mass fraction of the individual components of the curable adhesive relates to weighing and thus to the curable adhesive at 0% conversion.

[0061] Preferred is a tape according to the present utility model, wherein the reactive curable adhesive contains at least one photoactivatable substance, which initiates the chemical transformation of the reactive components by activation with UV light or visible light, and wherein the chemical transformation of the reactive components of the adhesive in the edge region is carried out by irradiating the outer edge with UV light or visible light having a wavelength required for activation with the photoactivatable substance.

[0062] The UV light is particularly and preferably UV-A radiation within the scope of the present invention, especially radiation within the wavelength range of 320 to 390 nm.

[0063] Particularly preferred is a tape according to the present invention, wherein the reactive curable adhesive comprises at least one photoinitiator for initiating cationic polymerization or at least one photo-redox system for initiating free radical polymerization, and the wavelength of visible light or UV light is selected such that it corresponds to the activation wavelength of the photoinitiator or the photo-redox system.

[0064] The at least one photoinitiator for initiating cationic polymerization or at least one photo-redox system for initiating free radical polymerization represents a particularly advantageous embodiment of the above-mentioned at least one photoactivatable substance.

[0065] Such systems are known to the person skilled in the art as described above.

[0066] For example, EP 3757183 A1 and DE 10 2021 125429A1 disclose adhesives comprising at least one photo-redox system for initiating free radical polymerization.

[0067] The photo-redox system particularly includes c) at least one initiator and d) at least one photo-redox catalyst within the scope of the present invention.

[0068] Within the scope of the present invention, the term "initiator", especially "free radical initiator" or free radical-forming substance (or curing agent) refers to a compound capable of initiating the polymerization reaction or crosslinking of the adhesive. However, the initiator, especially the free radical initiator, only accounts for a very small proportion during the reaction and thus does not form a polymer component that determines the adhesion properties.

[0069] Within the scope of the present invention, the term "redox catalyst" represents a compound that can mediate the electron transfer between compounds, which would otherwise react more slowly or not at all.

[0070] Within the scope of the present utility model, the term "photoredox catalyst" correspondingly represents a photo- or UV-sensitive compound which, when excited by light or UV light, can mediate the electron transfer between compounds which would otherwise react more slowly or not at all. In contrast to photoinitiators disclosed, for example, in EP 3910715A1, the photoredox catalyst does not decompose into reactive fission products upon irradiation with light or UV light, but only assumes an excited state which is generally of relatively long lifetime and can initiate or mediate redox processes therefrom. At temperatures up to 90 °C, the photoredox catalyst preferably does not initiate polymerization in a mixture of monomers or oligomers which are free-radically polymerizable, even if the mixture is irradiated with UV light or blue light. This applies as long as no free-radical initiator or other initiating substance is added to the mixture.

[0071] Therefore, the photoredox catalyst is not an initiator or a free-radical initiator. When irradiated with UV light or blue light, it only activates the initiator which then initiates the polymerization. This delayed mechanism results in the so-called open time during which the tape can still be applied before the start of the reactive curing.

[0072] Neither the photoredox catalyst nor the initiator which can be immediately initiated for curing by, for example, photoactivation or thermal activation is an initiator within the scope of the present utility model.

[0073] Preferably, the initiator is a free-radical initiator, and mixtures of two or more initiators can be contemplated. All free-radical initiators known in the prior art can be used. Preferred free-radical initiators are peroxides, hydroperoxides and azo compounds.

[0074] According to a particularly preferred embodiment of the present utility model, the free-radical initiator is an organic peroxide. Particularly preferred are hydroperoxides, especially diisopropylbenzene hydroperoxide (or cumene hydroperoxide) (CAS No. 26762-93-6). Diisopropylbenzene hydroperoxide is preferably used in the form of a 50 wt% solution of diisopropylbenzene hydroperoxide in diisopropylbenzene, and is obtained under the trade name IHP-50. α,α-Dimethylbenzyl hydroperoxide, also known as cumene hydroperoxide (CAS No. 80-15-9), can also be used. In addition, for example, p-menthane hydroperoxide (CAS No. 26762-92-5), tert-amyl hydroperoxide (CAS No. 3425-61-4) or 1,1,3,3-tetramethylbutyl hydroperoxide (CAS No. 5809-08-5) can also be used.

[0075] According to a preferred embodiment, the combined mass fraction of the initiator, preferably a free radical initiator (which is preferably selected from hydroperoxides), in the curable adhesive is 0.1% to 9%, particularly preferably 0.1% to 5%, and very particularly preferably 0.1 to 2%, based on the mass of the curable adhesive.

[0076] Furthermore, within the scope of the present invention, the terms "redox catalyst" and "photoredox catalyst" should not be limited to the corresponding compounds not being consumed during the reaction.

[0077] Photoredox catalysts known to those skilled in the art can be used as photoredox catalysts. Photoredox catalysts are generally transition metal complexes having ruthenium, copper or iridium as the central atom (depending on the ligand, it is neutral or exists in cationic form).

[0078] Bidentate ligands can preferably be used as ligands for the transition metal complex, especially those having at least two interconnected heteroaromatic six-membered rings, for example in the form of biphenyl, which in turn can be part of a more complex structure - for example polycyclic aromatic hydrocarbons and / or bridged - bicyclic or polycyclic - aromatic hydrocarbons. If a ligand containing a biphenyl structural unit is used, in each case, one of the aromatic rings of the biphenyl can advantageously form a "tooth" of the ligand, thus obtaining bidenticity. The bicyclic aromatic compound - such as a biphenyl compound - or polycyclic aromatic compound as the ligand can be unsubstituted - i.e., each C atom carries a hydrogen atom - or monosubstituted or polysubstituted. The transition metal complex acts as a photoredox catalyst in the sense of the present invention here.

[0079] According to a preferred embodiment of the present invention, the photoredox catalyst is a transition metal complex having ruthenium as the central atom and bipyridine or monosubstituted or polysubstituted bipyridine derivatives as ligands.

[0080] In another preferred embodiment according to the present invention, the photoredox catalyst is a transition metal complex having iridium as the central atom and phenylpyridine or mono - or polysubstituted phenylpyridine derivatives as ligands.

[0081] Therefore, the reactive tape according to the present invention according to the foregoing embodiments is also preferred, which is characterized in that the photoredox catalyst includes ruthenium as the central atom and bipyridine or monosubstituted or polysubstituted bipyridine derivatives as ligands, or iridium as the central atom and phenylpyridine or monosubstituted or polysubstituted phenylpyridine derivatives as ligands.

[0082] Preferably, at least one photoredox catalyst is selected from: Ru(bpm) 2+ (such as tris(2,2′ - bipyrimidine)ruthenium(II) dichloride), Ru(bpz)3 2+ (such as tris(2,2'-bipyrazine)bis(hexafluorophosphate)ruthenium), Ru(bpy) 3 2+ , Ru(phen) 3 2+ (such as dichlorotris(1,10-phenanthroline)ruthenium(II)), Ir[dF(CF 3 )ppy] 2 (dtbbpy) + (such as [4,4′-bis(1,1-dimethylethyl)-2,2′-bipyridine-N1,N1′]bis[3,5-difluoro-2-[5-(trifluoromethyl)-2-pyridyl-N]phenyl-C]iridium(III) hexafluorophosphate), Ir(ppy) 2 (dtbbpy) + (such as [Ir(dtbbpy)(ppy) 2 [PF 6 )], in each case with one or more anions (or the counterions of the cation), such as chloride or hexafluorophosphate, Ir(Fppy) 3 or fac-Ir(ppy) 3 (fac-tris(2-phenylpyridine)iridium(III)), Ir(ppy) 3 ; and the copper complex dichloro-(1,10-phenanthroline)-copper(II) (CAS: 14783-09-6).

[0083] According to a particularly preferred embodiment of the present invention, the photoredox catalyst is tris(2,2'-bipyridyl)ruthenium(II) hexahydrate Ru(bpy)3Cl 2 ·6H 2 O.

[0084] According to a preferred embodiment, the combined mass fraction of the photoredox catalyst in the curable adhesive is at most 1%, particularly preferably 0.01% to 0.5%, and particularly preferably 0.01 to 0.1%, based on the mass of the curable adhesive.

[0085] Systems based on polymerizable epoxy compounds (which are cationically polymerized by the activation of a cationic photoinitiator), as described at the beginning, are also known to those skilled in the art and are disclosed, for example, in EP 4242277A1.

[0086] Those skilled in the art basically adjust the catalyst system for curing according to the application requirements, particularly the wavelength provided for the activation of the subsequent curing, and the polymerizable epoxy compound used.

[0087] As initiators for this cationic radiation (i.e., usually UV-induced) curing of epoxide compounds, systems based on sulfonium, iodonium, and metallocene can be used in particular.

[0088] For examples of sulfonium-based cations, reference can be made to the statements in US 6,908,722 B1.

[0089] Examples of anions used as counterions for the above cations can mention tetrafluoroborate, tetraphenylborate, hexafluorophosphate, perchlorate, tetrachloroferrate, hexafluoroarsenate, hexafluoroantimonate, pentafluoro-hydroxyantimonate, hexachloroantimonate, four-pentafluorophenylborate, tetrakis(pentafluoromethylphenyl)borate, bis(trifluoromethanesulfonyl)amide, and tris(trifluoromethanesulfonyl)methylate. In addition, particularly for iodonium-based initiators, chloride, bromide, or iodide can also be considered as anions, although initiators substantially free of chlorine and bromine are preferred. A powerful example of such a system is, for example, triphenylsulfonium hexafluoroantimonate. Further suitable initiators are disclosed, for example, in US 3,729,313 A, US 3,741,769 A, US 4,250,053 A, US 4,394,403 A, US 4,231,951 A, US 4,256,828 A, US 4,058,401 A, US 4,138,255 A, and US 2010 / 063221 A1.

[0090] Specific examples of the sulfonium salts that can be used are in particular triaryl sulfonium salts, which can be substituted by an acetyl group or a methyl group, for example optionally correspondingly substituted: triaryl sulfonium hexafluorophosphate, triaryl sulfonium tetrakis(pentafluorophenyl) borate, triphenyl sulfonium hexafluoroarsenate, triphenyl sulfonium hexafluoroborate, triphenyl sulfonium tetrafluoroborate, triphenyl sulfonium tetrakis(pentafluorobenzyl) borate, methyldiphenyl sulfonium tetrafluoroborate, methyldiphenyl sulfonium tetrakis(pentafluorobenzyl) borate, dimethylphenyl sulfonium hexafluorophosphate, triphenyl sulfonium hexafluorophosphate, triphenyl sulfonium hexafluoroantimonate, diphenylnaphthyl sulfonium hexafluoroarsenate, mesityl sulfonium hexafluorophosphate, methoxyphenyldiphenyl sulfonium hexafluoroantimonate, 4-butoxyphenyldiphenyl sulfonium tetrafluoroborate, 4-chlorophenyldiphenyl sulfonium hexafluoroantimonate, tris(4-phenoxyphenyl) sulfonium hexafluorophosphate, bis(4-ethoxyphenyl)methyl sulfonium hexafluoroarsenate, 4-acetylphenyldiphenyl sulfonium tetrafluoroborate, 4-acetylphenyldiphenyl sulfonium tetrakis(pentafluorobenzyl) borate, tris(4-thiomethoxyphenyl) sulfonium hexafluorophosphate, bis(methoxysulfonylphenyl)methyl sulfonium hexafluoroantimonate, bis(methoxynaphthyl)methyl sulfonium tetrafluoroborate, bis(methoxynaphthyl)methyl sulfonium tetrakis(pentafluorobenzyl) borate, bis(methylcarbonylphenyl)methyl sulfonium hexafluorophosphate, (4-octoxyphenyl)diphenyl sulfonium tetrakis(3,5-bis(trifluoromethyl)phenyl) borate, tris[4-4-(acetylphenyl)thiophenyl] sulfonium tetrakis(pentafluorophenyl) borate, tris(dodecylphenyl) sulfonium tetrakis(3,5-bis(trifluoromethyl)phenyl) borate, 4-acetamidophenyldiphenyl sulfonium tetrafluoroborate, 4-acetamidophenyldiphenyl sulfonium tetrakis(pentafluorobenzyl) borate, dimethylnaphthyl sulfonium hexafluorophosphate, trifluoromethyldiphenyl sulfonium tetrafluoroborate, trifluoromethyldiphenyl sulfonium tetrakis(pentafluorobenzyl) borate, phenylmethylbenzyl sulfonium hexafluorophosphate, 5-methylthianthrenium hexafluorophosphate, 10-phenyl-9,9-dimethylthioxanthium hexafluorophosphate, 10-phenyl-9-oxythioxanthium tetrafluoroborate, 10-phenyl-9-oxythioxanthium tetrakis(pentafluorobenzyl) borate, 5-methyl-10-oxythianthrenium tetrafluoroborate, 5-methyl-10-oxythianthrenium tetrakis(pentafluorobenzyl) borate, and 5-methyl-10,10-dioxythianthrenium hexafluorophosphate.

[0091] Specific examples of the iodonium salts which can be used are diphenyliodonium tetrafluoroborate, bis(4-methylphenyl)iodonium tetrafluoroborate, phenyl-4-methylphenyl iodonium tetrafluoroborate, bis(4-chlorophenyl)iodonium hexafluorophosphate, dinaphthyliodonium tetrafluoroborate, bis(4-trifluoromethylphenyl)iodonium tetrafluoroborate, diphenyliodonium hexafluorophosphate, bis(4-methylphenyl)iodonium hexafluorophosphate, diphenyliodonium hexafluoroarsenate, bis(4-phenoxyphenyl)iodonium tetrafluoroborate, phenyl-2-thienyl iodonium hexafluorophosphate, 3,5-dimethylpyrazolyl-4-phenyl iodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, 2,2'-diphenyliodonium tetrafluoroborate, bis(2,4-dichlorophenyl)iodonium hexafluorophosphate, bis(4-bromophenyl)iodonium hexafluorophosphate, bis(4-methoxyphenyl)iodonium hexafluorophosphate, bis(3-carboxyphenyl)iodonium hexafluorophosphate, bis(3-methoxycarbonylphenyl)iodonium hexafluorophosphate, bis(3-methoxysulfonylphenyl)iodonium hexafluorophosphate, bis(4-acetamidophenyl)iodonium hexafluorophosphate, bis(2-benzothienyl)iodonium hexafluorophosphate, diaryliodonium tris(trifluoromethylsulfonyl)methylides such as diphenyliodonium hexafluoroantimonate, diaryliodonium tetrakis(pentafluorophenyl)borates such as diphenyliodonium tetrakis(pentafluorophenyl)borate, [4-2-(hydroxy-n-tetradesiloxy)phenyl]phenyl iodonium hexafluoroantimonate, [4-2-(hydroxy-n-tetradesiloxy)phenyl]phenyl iodonium trifluoromethanesulfonate, [4-2-(hydroxy-n-tetradesiloxy)phenyl]phenyl iodonium hexafluorophosphate, [4-2-(hydroxy-n-tetradesiloxy)phenyl]phenyl iodonium tetrakis(pentafluorophenyl)borate, bis(4-tert-butylphenyl)iodonium hexafluoroantimonate, bis(4-tert-butylphenyl)iodonium hexafluorophosphate, bis(4-tert-butylphenyl)iodonium trifluoromethanesulfonate, bis(4-tert-butylphenyl)iodonium tetrafluoroborate, bis(dodecylphenyl)iodonium hexafluoroantimonate, bis(dodecylphenyl)iodonium tetrafluoroborate, bis(dodecylphenyl)iodonium hexafluorophosphate, bis(dodecylphenyl)iodonium trifluoromethanesulfonate, bis(dodecylphenyl)iodonium hexafluoroantimonate, bis(dodecylphenyl)iodonium trifluoromethanesulfonate, diphenyliodonium hydrogensulfate, 4,4'-dichlorodiphenyliodonium hydrogensulfate, 4,4'-dibromodiphenyliodonium hydrogensulfate, 3,3'-dinitrodiphenyliodonium hydrogensulfate, 4,4'-dimethyldiphenyliodonium hydrogensulfate, 4,4'-bis(succinimido)diphenyliodonium hydrogensulfate, 3-nitrodiphenyliodonium hydrogensulfate, 4,4'-dimethoxydiphenyliodonium hydrogensulfate, bis(dodecylphenyl)iodonium tetrakis(pentafluorophenyl)borate, (4-octyloxyphenyl)phenyl iodonium tetrakis(3,5-bis(trifluoromethyl)phenyl)borate and tolyl cumyl)iodonium tetrakis(pentafluorophenyl)borate; and ferrocenium salts (see, for example, EP 0 542 716 B1) such as η 5-(2,4-Cyclopentadien-1-yl)[1,2,3,4,5,6,9)-(1-methylethyl)benzene]iron.

[0092] Such cationic photoinitiators are usually used alone or as a combination of two or more photoinitiators. For example, when using a photoinitiator, a combination with a so-called sensitizer for adapting the activation wavelength of the photoinitiating system to the selected emission spectrum is particularly helpful for curable adhesives of the prior art. Such sensitizers are, for example, disclosed in the textbook "Industrial Photoinitiators: A technical guide" by A.W. Green in 2010.

[0093] Some cationic photoinitiators, such as the photoinitiator commercially available under the trade name Deuteron UV 1242, react only in a relatively short wavelength range within 220 to 250 nm. Activation by means of typical UV LEDs, which may be highly preferred from an application technology perspective, is not possible or at least not effective here, since the emission maximum of typical UV LEDs is at a wavelength of about 365 nm. To activate these cationic photoinitiators with typical UV LEDs, the concept of "radical promoter cationic curing" described in the literature is used. For this purpose, a radical initiator is added as a sensitizer, such as that commercially available under the trade name Omnirad BDK or Irgacure 651, which decays when excited with a higher wavelength (e.g., with a wavelength typical for UV LEDs of 365 nm). The radicals or other reactive species formed in this way activate the cationic initiator, which ultimately initiates the curing of the epoxide compound. Generally, in these cases where a sensitizer is used, the mass fraction of the cationic photoinitiator in the curable adhesive does not exceed 4% but is at least 0.1%, and is preferably in the range of 0.5% to 2%. The mass fraction of the sensitizer is generally not more than 3% and is preferably in the range of 0.5% to 2%.

[0094] Within the scope of the present utility model, the curable adhesive that can be reactively cured particularly preferably contains at least one photoinitiator for initiating cationic polymerization. The cationic photoinitiator is preferably selected from the above group and is particularly selected from sulfonium salts and iodonium salts here.

[0095] According to a particularly preferred embodiment, the combined mass fraction of the cationic photoinitiator in the curable adhesive is preferably 0.5 - 7%, particularly preferably 0.5 - 4%, very particularly preferably 0.5 - 3%, and further preferably 0.5 - 2%, based on the mass of the curable adhesive.

[0096] In a particularly advantageous embodiment, the cation of the photoinitiator is selected from acetyl- or methyl-substituted triarylsulfonium and is commercially available, for example, under the names Omnicat 270 (IGM Resins), QL 211 and QL 212 (Quang Li Chem.), Irgacure 290 (BASF), or phenyl-substituted diaryliodonium, which is commercially available, for example, under the names Omnicat 250 (IGM Resins), Speedcure 939, Speedccure 938, Speedcure 937 (Arkema), Deuteron 1240, Deuteron 1242 (Deuteron).

[0097] According to a particularly advantageous embodiment, at least one sulfonium salt is used as a cationic photoinitiator, such as, for example, and in particular, triarylsulfonium hexafluorophosphate substituted with acetyl groups (CAS: 953084-13-4) or triarylsulfonium tetrakis(pentafluorophenyl)borate substituted with acetyl groups or tris(4-(4-acetylphenyl)thiophenyl)sulfonium tetrakis(pentafluorophenyl)borate.

[0098] Preferred is a tape according to the present invention, wherein the curable reactive adhesive comprises at least the following components:

[0099] a) at least one polymer; and

[0100] b) at least one reactive resin; and

[0101] c) at least one photoinitiator for initiating cationic polymerization or at least one photo-redox system for initiating radical polymerization.

[0102] For component c), all of the previous embodiments apply, wherein preferably at least one photoinitiator for initiating cationic polymerization is included.

[0103] At least one reactive resin particularly represents the reactive component of the curable reactive adhesive.

[0104] In the case of at least one photoinitiator for initiating cationic polymerization, components a) and b) and additives are preferred.

[0105] Polymers a) and reactive resins b) suitable for cationic or radical polymerization are known to those skilled in the art.

[0106] In the case of cationic polymerization, the curable reactive adhesive preferably comprises one or more (co)polymers as polymer component a).

[0107] Those skilled in the art understand that the (co)polymer generally functions as a film-forming agent, which is particularly important since it is specifically intended to obtain a pressure-sensitive adhesive. Here, preferably, one or more (co)polymers are selected from poly(meth)acrylates, polyurethanes, polyvinyl acetals such as polyvinyl butyral, polysiloxanes, synthetic rubbers, polyesters, phenoxy polymers, polyvinyl alcohol, polyvinyl alcohol copolymers, and olefin-vinyl acetate copolymers, preferably selected from poly(meth)acrylates, phenoxy polymers, polyvinyl alcohol, polyvinyl alcohol copolymers, polyvinyl acetals such as polyvinyl butyral, and ethylene-vinyl acetate copolymers (EVA or EVAC, poly(ethylene-co-vinyl acetate)), particularly selected from poly(meth)acrylates, phenoxy polymers, and ethylene-vinyl acetate copolymers.

[0108] Additionally or alternatively, as the (co)polymer, block copolymers such as (meth)acrylate block copolymers can also be used. Corresponding examples are disclosed, for example, in documents US2011003947 A1, US 20080200589A1, US2007078236 A1, US2007078236 A1, US2012196952A1, US2016032157 A1, US2008146747A1, and US2016230054 A1.

[0109] According to a particularly advantageous embodiment, as the (co)polymer a), it contains at least one olefin-vinyl ester copolymer.

[0110] In particular, olefin-vinyl ester copolymers with a relatively high vinyl ester fraction are preferred because a low crystallinity, which has been proven to be particularly advantageous in the experiments of the present inventors, is advantageously obtained for the corresponding olefin-vinyl ester copolymers. Preferably, at least one olefin-vinyl ester copolymer is an ethylene-vinyl ester copolymer having a vinyl ester fraction of 60% or more, particularly 70% or more, based on the mass of the (co)polymer.

[0111] The ethylene-vinyl ester copolymer is preferably an ethylene-vinyl acetate copolymer (EVA) having an acetic acid vinyl ester fraction of 60% or higher, preferably 70% or higher, based on the mass of the (co)polymer. Suitable ethylene-vinyl acetate copolymers are obtained under the trade name 700 from Arlanxeo Corporation, which has a vinyl acetate content of 70% by weight.

[0112] (The number-average molar mass M of the (co)polymer nPreferably in the range of 50,000 to 10,000,000 g / mol, more preferably in the range of 100,000 to 5,000,000 g / mol, very preferably in the range of 150,000 to 2,000,000 g / mol. The number-average molar mass M n of which is determined herein by gel permeation chromatography (GPC). The measurement is carried out on 100 μl of a clarified and filtered sample (sample concentration 4 g / l). The eluent used is tetrahydrofuran with 0.1% by volume of trifluoroacetic acid. The measurement is carried out at 25 °C. The pre-column used is a PSS-SDV type column, 5 μm, 8.0 mm * 50 mm (the information here and below is in the following order: type, particle size, porosity, inner diameter * length; ). The separation is carried out using a combination of PSS-SDV type columns, 5 μm, and and each 8.0 mm * 300 mm (columns from Polymer Standards Service; detected by means of a Shodex RI71 differential refractometer). The flow rate is 1.0 ml / minute. Calibration is carried out with a commercially available ReadyCal-Kit Poly(styrene) high from PSS Polymer Standard Service GmbH, Mainz or Agilent. In the case of polyacrylates, calibration is carried out against a PMMA standard (polymethyl methacrylate calibration), and in the case of other (resins, elastomers), calibration is carried out against a PS standard (polystyrene calibration).

[0113] Regardless of the specific choice of (co)polymer, preferably, the combined mass fraction of the (co)polymer in the curable adhesive is in the range of 20 to 55%, preferably in the range of 20 to 50%, particularly preferably in the range of 25 to 50%, very particularly preferably in the range of 25 to 45%, extremely preferably in the range of 30 to 45%, based on the mass of the curable adhesive.

[0114] Within the scope of the present utility model, the "reactive resin" should be understood to refer to polymerizable compounds.

[0115] As understood by those skilled in the art, the expression "polymerizable" herein means the ability of these compounds to enter into a polymerization reaction under appropriate circumstances after suitable activation. In the case of polymerizable epoxy compounds, for example, polymerizability is achieved through epoxy groups.

[0116] In the case of cationic polymerization, the curable adhesive comprises one or more reactive resins b), which preferably comprise at least one compound selected from epoxide compounds, vinyl ethers, and oxetanes.

[0117] Particularly preferably, one or more reactive resins b) are at least one polymerizable epoxide compound in the case of cationic polymerization.

[0118] As understood by those skilled in the art, an epoxide compound is a compound carrying at least one oxirane group.

[0119] Preferred is a tape according to the present invention, wherein the curable adhesive comprises one or more polymerizable epoxide compounds selected from polymerizable epoxide compounds having a weight-average molecular weight Mw in the range of 300 to 2000 g / mol, preferably in the range of 300 to 1500 g / mol, and particularly preferably in the range of 350 to 1300 g / mol as measured by GPC. Additionally or alternatively, particularly preferred is also a curable tape according to the present invention, wherein the curable adhesive comprises one or more polymerizable epoxide compounds selected from polymerizable epoxide compounds having a weight-average molecular weight Mw of 2000 g / mol or less as measured by GPC.

[0120] The polymerizable epoxide compound can be, for example, aromatic or aliphatic in nature, more particularly cycloaliphatic. The polymerizable epoxide compound often has an average of at least two epoxide groups per molecule, preferably more than two epoxide groups per molecule. Preferably, one or more polymerizable epoxide compounds are selected from epoxide compounds having two or more epoxide groups, preferably two epoxide groups.

[0121] Exemplary polymerizable epoxide compounds include cyclohexene oxide carboxylates, such as 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-2-methylcyclohexylmethyl 3,4-epoxy-2-methylcyclohexanecarboxylate, and bis(3,4-epoxy-6-methylcyclohexylmethyl) adipate. Other examples of polymerizable epoxide compounds are disclosed, for example, in US 3,117,099 A. Further polymerizable epoxide compounds that are particularly useful in the context of the present invention include glycidyl ether monomers, as disclosed, for example, in US 3,018,262. Examples are glycidyl ethers of polyphenols, which are obtained by reacting a polyphenol with an excess of chlorohydrin, such as epichlorohydrin (e.g., the diglycidyl ether of 2,2-bis(2,3-epoxypropoxyphenol) propane). In particular, the diglycidyl ethers of bisphenols such as bisphenol-A (4,4′-(propane-2,2-diyl)diphenol) and bisphenol-F (bis(4-hydroxyphenyl)methane). Such reaction products are commercially available in different molecular weights and aggregation states (e.g., the so-called type 1 to type 10 BADGE resins). Typical examples of liquid bisphenol-A diglycidyl ether are Epikote 828, D.E.R. 331, Araldite GY 250CH, and Epon 828. Typical solid BADGE resins are Araldite GT6071, GT7072, Epon 1001, and D.E.R. 662. Other reaction products of phenol and epichlorohydrin are phenol and cresol novolac resins, such as Epiclon products or Araldite EPN and ECN products (e.g., ECN 1273).

[0122] Herein, it is preferred that one or more polymerizable epoxide compounds are selected from epoxide compounds having at least one alicyclic group, more particularly a cyclohexyl group or a dicyclopentadienyl group. Additionally or alternatively, it is preferred that one or more polymerizable epoxide compounds are selected from bisphenol-A diglycidyl ether and bisphenol-F diglycidyl ester, preferably bisphenol-A diglycidyl ether.

[0123] According to the inventors' estimates, particularly advantageous curable adhesives can be obtained by using two or more different polymerizable epoxy compounds, especially if they differ in their state of aggregation at room temperature. Preferably, the curable adhesive comprises one or more polymerizable epoxy compounds selected from epoxy compounds which are solid at 25 °C or which are highly viscous substances having a dynamic viscosity of 50 Pa s or greater, preferably 100 Pa s or greater, particularly preferably 150 Pa s or greater, and / or the curable adhesive comprises one or more polymerizable epoxy compounds selected from epoxy compounds which are liquids having a dynamic viscosity of 40 Pa s or less, preferably 20 Pa s or less, very preferably 10 Pa s or less at 25 °C. Within the scope of the present utility model, the dynamic viscosity is determined in accordance with DIN 53019-1 from 2008; at 25 °C, at a shear rate of 1 s -1 -1.

[0124] Regardless of the specific choice of the polymerizable epoxy compounds, preferably, the combined mass fraction of the polymerizable epoxy compounds in the curable adhesive is in the range of 20 to 60%, preferably in the range of 30 to 55%, particularly preferably in the range of 30 to 45%, very preferably in the range of 30 to 40%, based on the mass of the curable adhesive.

[0125] As a further component, the curable adhesive preferably comprises at least one epoxy-modified nitrile rubber. The epoxy-modified nitrile rubber is in particular a liquid, usually highly viscous, polymeric epoxy resin which has a base skeleton consisting of a nitrile rubber modified with epoxy groups, the epoxy groups being introduced by modification with an epoxy resin or an epoxy prepolymer, wherein the mass fraction of the nitrile rubber is preferably in the range of 5 to 50%, particularly preferably in the range of 10 to 40, very particularly preferably in the range of 10 to 25%, based on the mass of the epoxy-modified nitrile rubber. As will be understood by the person skilled in the art, the expression "epoxy-modified nitrile rubber" thus refers to the conversion product of an optionally functionalized nitrile rubber and an epoxy resin. In order to achieve good miscibility with the relatively polar epoxy resin or epoxy prepolymer, the nitrile rubber polymer on which the epoxy-modified nitrile rubber is based comprises a mass fraction of acrylonitrile of at least 20% and at most 50%, particularly the mass fraction of acrylonitrile being in the range of 25% to 40%.

[0126] The expression nitrile rubber is known to those skilled in the art here and refers to a butadiene-acrylonitrile copolymer. In order to incorporate epoxy groups into the butadiene-acrylonitrile copolymer, one or more additional monomers having functional groups, such as carboxylic acid groups, such as acrylic acid, can be copolymerized during manufacture. From carboxylic acids and nitrile rubbers, for example, so-called carboxyl-terminated nitrile rubbers (CTBN) or carboxylated nitrile rubbers are obtained as precursors of epoxy group-modified nitrile rubbers, where carboxylic acid groups can also be present additionally or alternatively in the polymer chain. CTBN is also commercially available and is provided, for example, by B.F. Goodrich under the trade name Hycar. This has, for example, a weight-average molar mass in the range from 2000 to 5000 g / mol and an acrylonitrile content in the range from 10 to 30%. Specific examples are Hycar CTBN 1300x 8, 1300x 13 or 1300x 15. By reacting CTBN with an epoxy resin or an epoxy prepolymer, an epoxy group-modified nitrile rubber, such as an epoxy group-terminated nitrile rubber (ETBN), can be obtained under suitable conditions. Such epoxy group-terminated nitrile rubbers, especially ETBN, can be commercially obtained, for example, from Emerald Materials under the name HYPRO ETBN (formerly Hycar ETBN), for example under the trade names Hypro1300X40 ETBN, Hypro 1300X63 ETBN and Hypro 1300X68 ETBN. In addition, such epoxy group-modified nitrile rubbers from Schill+Seilacher “Struktol” GmbH are obtained under the trade name Polydis, for example under the names Polydis 3604 or 3605, 3606, 3610, 3611, 3614, 3615, 3616, 3618, 3633, 3636, 3652, 3670, 3691, 3693, 3694S, 3695 or 3696S. Epoxy group-modified nitrile rubbers are sometimes also provided as epoxy resins modified with nitrile rubbers, where this name is especially for a perspective issue and is, according to the inventor's estimation, in many cases mainly based on the mass fraction of the components converted together.

[0127] According to the inventor's estimation, preferably, one or more epoxy group-modified nitrile rubbers are selected from epoxy group-modified nitrile rubbers having an average functionality of 2 or greater, preferably 2.5 or greater, particularly preferably 3 or greater. Additionally or alternatively, preferably, one or more epoxy group-modified nitrile rubbers are selected from epoxy group-modified nitrile rubbers having terminal epoxy groups and / or epoxy groups arranged in the chain.

[0128] According to the estimation of the inventor of the present utility model, it is particularly preferred that one or more epoxy group-modified nitrile rubbers are selected from epoxy group-modified nitrile rubbers having a weight-average molar mass Mw measured by GPC in the range of 5,000 to 35,000 g / mol, preferably in the range of 10,000 to 30,000 g / mol, and particularly preferably in the range of 15,000 to 25,000 g / mol.

[0129] The inventors have found, surprisingly, that especially this epoxy group-modified nitrile rubber results in improved adhesion and shows at least one bimodal distribution in GPC. Without wishing to be bound by this theory, the inventors assume that this achieves a balance between the adhesive properties and the cohesive properties. By "at least bimodal", the inventors understand herein a GPC curve that contains more than one maximum or whose mathematical derivation of the molecular weight distribution intersects the x-axis at least twice. Therefore, it is preferred that one or more epoxy group-modified nitrile rubbers are selected from epoxy group-modified nitrile rubbers having at least a bimodal weight-average molar mass distribution.

[0130] Since the GPC results only provide relative information about the molecular weight and the quality of the measured values and resolution strongly depends on the type of column, the weight-average molar mass distribution considered to be preferred can be characterized relative to the peak of the highest molecular fraction. Particularly preferred are those epoxy group-modified nitrile rubbers that show at least two additional molar mass maxima in GPC in addition to the highest molecular peak. Such a specific molecular weight distribution can be obtained, for example, in a method in which CTBN is converted with an epoxy resin (or CTBN reacts with an epoxy resin) and the chain is extended by adding a diol or a polyol such as bisphenol A.

[0131] Additionally or alternatively, it is particularly preferred that one or more epoxy group-modified nitrile rubbers are selected from epoxy group-modified nitrile rubbers having a weight-average molar mass Mw measured by GPC greater than 2,000 g / mol.

[0132] Regardless of the specific selection of the epoxy group-modified nitrile rubber, it is preferred that the combined mass fraction of the epoxy group-modified nitrile rubber in the curable adhesive is in the range of 3.5 to 25%, preferably in the range of 4 to 20%, and particularly preferably in the range of 4.5 to 18%, based on the mass of the curable adhesive.

[0133] As an advantage of the present utility model, it can be seen that the reactivity-curable adhesive is very flexible with respect to the presence of other components, enabling the physicochemical properties to be particularly tailored in a favorable manner to the various requirements of the application. For example, it is preferred that the curable adhesive includes one or more polyols, preferably in a combined mass fraction of 0.5 to 15%.

[0134] Additionally or alternatively, preferably, the curable adhesive comprises one or more additional additives, preferably in a combined mass fraction in the range of 0.1 to 50%, particularly preferably in the range of 0.2 to 40%, based on the mass of the curable adhesive, and / or one or more of the additional additives are preferably selected from adhesive resins, anti-aging agents, light protection agents, UV absorbers, rheological additives, and additives for increasing opacity.

[0135] In the case of at least one photo-redox system for initiating radical polymerization, the preferred components a) and b) and additives

[0136] In the case of radical polymerization, the reactive curable adhesive further preferably comprises one or more (co)polymers as polymer component a).

[0137] According to a preferred embodiment of the present invention, the (co)polymer is selected from ethylene-vinyl acetate copolymers (EVA), poly(meth)acrylates, polyurethanes (PU), polyvinyl acetates (PVA), polyacetals such as particularly polyvinyl butyral (PVB), polyesters, and polymers formed from monomers including N-vinyl compounds.

[0138] Particularly preferred are polymers selected from ethylene-vinyl acetate copolymers (EVA), poly(meth)acrylates, poly(N-vinylcaprolactam), poly(N-vinylpyrrolidone), and polyurethanes (PU).

[0139] In the case of radical polymerization, the reactive curable adhesive comprises one or more reactive resins b), which preferably comprise at least one free-radically polymerizable monomer or oligomer.

[0140] As understood by those skilled in the art, the free-radically polymerizable monomer or oligomer should represent a monomer or oligomer capable of free-radical chain polymerization.

[0141] Those skilled in the art understand that, particularly distinct from polymers, free-radically polymerizable oligomers are particularly free-radically polymerizable compounds having a weight-average molecular weight distribution Mw of less than 35,000 g / mol, particularly less than 15,000 g / mol, and especially less than 10,000 g / mol. And within the scope of the present utility model, they are particularly epoxide compounds, acrylated and / or methacrylated ether oligomers, butadiene oligomers, ester oligomers, carbonate oligomers or silicone oligomers having a weight-average molecular weight distribution Mw of less than 35,000 g / mol, particularly less than 15,000 g / mol, and especially less than 10,000 g / mol. These are particularly epoxy-(meth)acrylates, aliphatic and aromatic silicone carbamate-(meth)acrylic acids, aliphatic and aromatic polyester-(meth)acrylates, polybutadiene-(meth)acrylates, dendritic (meth)acrylates, polyether-(meth)acrylates and polycarbonate-(meth)acrylamides, which can be obtained from Miwon and Bomar, for example, MIRAMER SC2565 from Miwon Co., Ltd. with an Mw of 5200 g / mol, or oligomers based on aliphatic polyurethanes, particularly polyester-polyurethanes, for example, aliphatic carbamate diacrylates obtained under the trade names 8402, 48582 or 8809, or acrylated low polyesters based on caprolactone, such as commercially available hydroxyethyl acrylate caprolactone (HECLA; CAS No.: 110489-05-9). Preferably, the functionality of the polymerizable oligomer (i.e., the number of free-radically polymerizable groups per molecule) is 1 to 20, usually 2 to 15, and mainly 2 to 6. The dynamic viscosity at 25 °C measured according to DIN 53019-1 in 2008 is preferably greater than 1 Pas, but particularly preferably significantly higher than 10 Pas. In particular, in order to manufacture a good pressure-sensitive adhesive with sufficient cohesion, the oligomer is suitable as a component of the adhesive, and its dynamic viscosity at 25 °C is greater than 20 Pas, preferably greater than 30 Pas. Within the scope of the present utility model, the dynamic viscosity is measured according to DIN 53019-1 in 2008; at 25 °C, it is measured at a shear rate of 1 s -1 .

[0142] According to a preferred embodiment, the boiling point of at least one free-radically polymerizable monomer or oligomer at 1 mbar is at least 30 °C, preferably at least 60 °C, and particularly preferably at least 80 °C, or it exists in solid form at 23 °C. In this case, free-radically polymerizable oligomers are particularly preferred.

[0143] Suitable free-radically polymerizable monomers are selected from acrylates (such as 2-hydroxy-3-phenoxypropyl acrylate), methacrylates, vinyl compounds, and compounds having carbon-carbon double bonds, as well as crosslinkable free-radically polymerizable monomers such as diacrylates, dimethacrylates, triacrylates, trimethacrylates, and higher-functional acrylates or higher-functional methacrylates.

[0144] Suitable free-radically polymerizable oligomers are in particular oligomer substances having acrylate or methacrylate functionality or vinyl functionality, where the functionalization can be mono-functional or multi-functional.

[0145] Preferably, in the free-radically polymerizable reactive adhesive variant of the reactive tape according to the present utility model, the weight ratio of all polymers to all free-radically polymerizable monomers or oligomers is from 3:1 to 1:3, more preferably from 2:1 to 1:2, and especially from 2:1 to 1:1.

[0146] Additional additives and / or auxiliaries

[0147] In the case of free-radical polymerization, the curable reactive adhesive can also contain additional additives and / or auxiliaries known from the prior art. The combined mass fraction of the additional additives and / or auxiliaries can be in the range from 0 to about 20%, preferably from 0 to 15%, more preferably from 0 to 10%, and most preferably from 0 to 5%, where in the case of containing additives, the combined mass fraction is preferably at least 0.1%. In each case based on the mass of the curable adhesive,

[0148] As additional additives and / or auxiliaries, for example, fillers, dyes, nucleating agents, rheological additives (such as pyrogenic silica), blowing agents, adhesion enhancers (adhesion promoters, especially silanes and tackifier resins), compounding agents, plasticizers, and / or anti-aging agents, light and UV protectants, for example, in the form of primary antioxidants and secondary antioxidants, can be mentioned.

[0149] In particular and according to a preferred embodiment, the filler, such as glass beads or The proportion of 5211 is up to 50% by mass fraction, especially up to 40%.

[0150] According to a preferred embodiment, the free-radically polymerizable reactive adhesive contains at least one rheological modifying filler, such as silica, and particularly preferably in a combined mass fraction of from 1 to 10%, especially preferably from 2 to 5%.

[0151] In the case where the curable adhesive is reactive and has both at least one photoinitiator for initiating cationic polymerization and at least one photo - redox system for initiating radical polymerization, the above - described embodiments are similarly applicable, where those skilled in the art appropriately select the resulting combined mass fractions of these components as well as the types and amounts of the polymer, reactive resin, and additives.

[0152] Pressure - sensitive adhesiveness

[0153] Preferably, the adhesive in at least the intermediate region is pressure - sensitive adhesive, and in particular and preferably before the start of chemical conversion, i.e., at a degree of 0% chemical conversion. Thus, the adhesive in the intermediate region is preferably a pressure - sensitive adhesive.

[0154] Preferably, due to the partial chemical conversion of the reactive components, the adhesive in the correspondingly treated edge region is not (any longer) pressure - sensitive adhesive.

[0155] As understood by those skilled in the art, a pressure - sensitive adhesive is understood to be an adhesive having pressure - sensitive adhesive properties, i.e., the ability to form a permanent bond with an adherend substrate even under relatively weak applied pressure. The corresponding pressure - sensitive tapes can typically be separated (peeled) from the adherend substrate with substantially no residue after use, and generally have a permanent inherent tack even at room temperature, which means that they have a certain viscosity and touch tack (contact tack) such that they can wet the surface of the substrate even under low applied pressure. The pressure - sensitive adhesiveness of a pressure - sensitive tape is the result of using a pressure - sensitive adhesive as the adhesive. Without wishing to be bound by this theory, it is often assumed that a pressure - sensitive adhesive can be regarded as a fluid of extremely high viscosity having elastic components (constituents), which correspondingly have characteristic visco - elastic properties resulting in the above - mentioned permanent inherent tack and pressure - sensitive adhesive ability. It is assumed that in the case of a corresponding pressure - sensitive adhesive, during mechanical deformation, there is a viscous flow process and the formation of elastic restoring forces. A proportional (in a certain proportion) viscous flow is used to achieve adhesion, while a proportional (in a certain proportion) elastic restoring force is particularly required to achieve cohesion. The relationship between rheology and pressure - sensitive adhesiveness is known in the prior art and is described, for example, in Satas, "Handbook of Pressure Sensitive Adhesives Technology", Third Edition (1999), pages 153 to 203. To characterize the degree of elastic and viscous components, the storage modulus (G′) and loss modulus (G″) are usually employed, which can be determined by dynamic mechanical analysis (DMA) using, for example, a rheometer as disclosed, for example, in WO2015 / 189233. Within the scope of the present utility model, when at a temperature of 23 °C at 10 0 to 10 1In the deformation frequency range in radians per second, G′ and G″ are each at least partially in the range of 10 3 to 10 7 Pa, the adhesive is preferably understood to be pressure-sensitive tacky and thus a pressure-sensitive adhesive.

[0156] Regarding the most favorable processing properties, particularly favorable results are often achieved in such a situation, i.e., when a reactive curable adhesive is used as the adhesive layer of a single-sided or double-sided tape, when the single-sided or double-sided tape further includes a carrier layer or when the adhesive layer is arranged on a release layer such as a liner (from which the adhesive layer can be easily peeled).

[0157] The tape according to the present invention can thus be a so-called transfer tape, which consists of the above-mentioned reactive curable adhesive layer.

[0158] However, preferably, the tape according to the present invention further has at least one carrier layer.

[0159] The carrier layer generally refers to the layer of such a multi-layer tape, which critically determines the mechanical and physical properties of the tape, such as tensile strength, stretchability, insulating ability or resilience (elasticity, elastic force). Conventional materials for the carrier layer are, for example, woven fabrics, laid scrims and plastic foils, such as PET foils and polyolefin foils. However, the carrier layer itself can also be pressure-sensitive tacky.

[0160] In a preferred embodiment, the tape according to the present invention can be a double-sided tape, the carrier layer of which is provided with the reactive curable adhesive as described above on both sides.

[0161] In this case, preferably, each layer of the reactive curable adhesive has a corresponding edge region, so that further no adhesive overflows from the tape, especially from the tape roll.

[0162] Preferably, the carrier layer comprises a foil.

[0163] The carrier layer can also have electrical insulation properties, so that the corresponding tape according to the present invention is electrically insulating and can be used for electrical insulation of articles. For this purpose, an insulating carrier foil having a specific volume resistivity of > 10 15 Ωcm, preferably > 10 16 Ωcm, more preferably > 10 17 Ωcm as determined according to DIN EN 62631-3-1 (VDE 0307-3-1): 2017-01 can be used.

[0164] Therefore, in a preferred embodiment, the tape according to the present invention can be a double-sided tape, the insulating carrier foil of which is provided with the reactive curable adhesive on both sides.

[0165] Preferably, the tape according to the present invention is a single-sided tape.

[0166] More preferably, the tape according to the present invention is a single-sided tape, and its electrically insulating carrier foil is provided with a reactively curable adhesive on one side. Such a single-sided tape is very suitable for encapsulating battery cells in hybrid electric vehicles and all-electric vehicles.

[0167] Preferably, the carrier foil preferably having simultaneous insulation comprises one or more materials selected from the following: polyimide, polybenzimidazole, polyamide, polyetherimide, polyacetal, polyphenylene sulfide, polyether ether ketone, polytetrafluoroethylene, nylon 6, ultra-high molecular weight polyethylene, polypropylene, vinyl chloride resin, polystyrene, polyethylene terephthalate, acrylonitrile-butadiene-styrene, polycarbonate, polyvinyl chloride, ethylene-vinyl acetate copolymer and polyester, more preferably selected from polypropylene, polyethylene terephthalate, polycarbonate and polyvinyl chloride, and still more preferably selected from polypropylene and polyethylene terephthalate (PET), wherein the foil particularly preferably comprises PET.

[0168] Regarding the thickness of the carrier, there is no particular limitation in principle. The thickness of the carrier is preferably in the range of 20 μm to 100 μm, more preferably in the range of 30 μm to 90 μm, and still more preferably in the range of 40 μm to 75 μm.

[0169] Another subject of the present invention is a method for manufacturing a tape with side-edge passivation, especially a roll of tape with side-edge passivation, which at least includes the following method steps:

[0170] i.) Providing an adhesive, especially a reactively curable adhesive, which comprises reactive components, and curing is carried out through the chemical conversion of the reactive components;

[0171] ii.) Optionally providing a carrier layer;

[0172] iii.) Coating the adhesive on the carrier layer in step ii.) or a releasable layer such as a liner, thereby providing a tape comprising at least one adhesive layer;

[0173] iv.) Optionally rolling up the tape into a roll;

[0174] v.) Optionally cutting the tape or the tape roll;

[0175] vi.) Treat the outer edge of the tape or tape roll to initiate a chemical transformation of the reactive components of the adhesive such that the chemical transformation of the reactive components of the adhesive in the edge region takes place in each case to an extent of at least 30% and to a greater extent than in the intermediate region, and wherein the chemical transformation preferably takes place in the intermediate region to an extent of 0 to 10%, particularly preferably 0 to 5%, especially 0%, and wherein the treatment is preferably carried out by irradiating the outer edge, in particular with visible light or UV light.

[0176] For the reactive curable adhesive, the carrier layer, and the irradiation, all the above-described embodiments apply.

[0177] In particular and preferably, the treatment of the outer edge is carried out such that the chemical transformation of the reactive components of the adhesive takes place in the edge region to an extent such that no adhesive laterally spills out of the tape. Here, compared to the intermediate region, the treatment increases the viscosity of the adhesive in the edge region.

[0178] In particular, it is preferred here to include a photoinitiator for initiating cationic polymerization as the photoactivatable substance and the reactive resin includes at least one epoxy compound.

[0179] The present invention also relates to the use of the tape according to the present invention for bonding two or more components by curing a curable adhesive.

[0180] A further subject of the present invention is the use of the tape according to the present invention for bonding components in electronic, optical or precision mechanical equipment, automotive, medical equipment and dental equipment, in particular batteries or accumulators.

[0181] Regarding effective curing, the use according to the present invention is preferably as follows, wherein the curable adhesive is cured with a minimum dose of 4000 mJ / cm 2 or greater, preferably 5000 mJ / cm 2 or greater, particularly preferably 6000 mJ / cm 2 or greater.

[0182] Preferably, for all the subjects according to the present invention, the curable adhesive is cured with a UV LED, preferably with a maximum emission wavelength in the range of 320 to 410 nm, particularly preferably in the range of 340 to 390 nm, very preferably in the range of 360 to 370 nm, especially at 365 nm.

[0183] As described above, from the perspective of applied technology, it is particularly preferred here that curing is carried out by means of typical UV LEDs, which is feasible for curable adhesives, although in this case the effectiveness of the sensitizer is reduced and is even feasible in the case of a high content of epoxy-modified nitrile rubber. It is particularly preferred that the cationic photoinitiator is matched to the emission characteristics of the UV LED, in particular by adjusting the above-defined mass ratio between the cationic photoinitiator and the epoxy-modified nitrile rubber. Detailed Description of the Invention

[0184] Hereinafter, some embodiments are described to further clarify the present invention.

[0185] Test Methods

[0186] Unless otherwise specified, all measurements were carried out at 23 °C and 50% relative air humidity. The mechanical and adhesion data obtained are as follows:

[0187] Number-average molar mass Mn, weight-average molar mass Mw

[0188] The information on the number-average molar mass Mn or the weight-average molar mass Mw in this specification relates to the determination by gel permeation chromatography (GPC). The determination was carried out on 100 μl of a clarified and filtered sample (sample concentration 4 g / l). The eluent used was tetrahydrofuran with 0.1% by volume of trifluoroacetic acid. The measurement was carried out at 25 °C. The pre-column used was a PSS SDV column, 5 μm, 8.0 mm * 50 mm (here and in the following statements in the following order: type, particle size, porosity, inner diameter * length; ). The separation was carried out using the following combination: PSS SDV column, 5 μm, and and each 8.0 mm × 300 mm (columns from Polymer Standards Service; detection was carried out using a Shodex RI71 differential refractometer). The flow rate was 1.0 ml / minute. Calibration was carried out using commercially available Poly(styrene)high from PSS Polymer Standards Service GmbH, Mainz or Agilent. Calibration was carried out against a PMMA standard (polymethyl methacrylate calibration), and in other cases against a PS standard (polystyrene calibration).

[0189] Thickness

[0190] The thickness of the adhesive layer can be determined as follows: Measure the thickness of such a part (section) of the adhesive layer applied to the backing, which is defined by its length and its width, and subtract the thickness of the part (section) of the backing used, which has the same dimensions (known or separately measurable). A commercial thickness gauge (probe instrument) with an accuracy of less than 1 μm deviation can be used to determine the thickness of the adhesive layer. If fluctuations in the thickness are measured, report the average of the measured values at at least three representative positions, i.e., in particular, do not measure at wrinkles, creases, tips, etc.

[0191] Similar to the thickness of the adhesive layer, the thickness of the tape (adhesive strip) or the carrier can also be measured using a commercial thickness gauge (probe instrument) with an accuracy of less than 1 μm deviation. If fluctuations in the thickness are measured, report the average of the measured values at at least three representative positions, i.e., in particular, do not measure at wrinkles, creases, tips, etc.

[0192] The following examples (marked as "E") and comparative examples (marked as "V") according to the present utility model for tapes or tape rolls were prepared.

[0193] A reactive curable pressure-sensitive adhesive (pilot plant; coating from a 60% strength methyl ethyl ketone solution) was obtained from the components summarized below by mixing the components in a conventional manner (the numbers are in parts by weight):

[0194] 34.4% 700 (ethylene-vinyl acetate copolymer, vinyl acetate content 70 wt%, Arlanxeo Corporation)

[0195] 17.1% D.E.R. 331 (liquid bisphenol-A diglycidyl ether, weight average molar mass Mw < 2000 g / mol, Olin Corporation)

[0196] 17.1% D.E.R. 662E (solid bisphenol-A diglycidyl ether, weight average molar mass Mw < 2000 g / mol, Olin Corporation)

[0197] 17.1% Polydis 3610 (epoxy-modified nitrile rubber, Schill+Seilacher "Struktol" GmbH)

[0198] 12.8% Capa 3050 (polycaprolactone-based polyester polyol, Ingevity Corporation) and

[0199] 1.5% triarylsulfonium hexafluorophosphate CAS: 109037-77-6 (50% strength in propylene carbonate, the weighing data relates to the solution, Sigma-Aldrich Corporation).

[0200] For each of the examples prepared from a 60% concentration methyl ethyl ketone solution, the pressure-sensitive adhesive obtained was in each case coated onto a silicated PET liner with a layer thickness of 50 μm. After the drying section (10 m, 120 °C), a 50-μm thick blue PET foil was laminated (pasted) on, and the composite (total layer thickness 100 μm) was rolled up into a tape roll with a width of 125 cm in the y-direction.

[0201] On a cutting machine, four rolls each 30 cm wide in the y-direction and 50 m long were cut from this master roll.

[0202] Side-edge passivation was carried out on the same day.

[0203] Side-edge passivation

[0204] For side-edge passivation, an exemplary reactive tape roll was irradiated on each side, i.e., on each of the two outer edges in the y-direction. The light source was selected to match the activation wavelength of the reactive tape. For the above exemplary reactive adhesive, a 365-nm LED light source from the company was suitable and was used accordingly. The dose in the UV-A range (320 nm–390 nm) was measured using a UV Power Puck II from UVECO (EIT) company.

[0205] As shown in Table 2, in Examples E1 to E3 and V2 and V3, the irradiation dose was varied, resulting in different widths of the activated regions.

[0206] The data in Table 2 relate to one of the irradiated sides, but the exact same irradiation was carried out on both sides.

[0207] In addition, no irradiation was carried out in Comparative Example V1.

[0208] Then, the width of the activated region (width of each edge region) was optically measured using a VK-X3000 type 3D laser scanning microscope from Keyence Corporation and a CF ICEPIPlan 5x lens (magnification 84 - 960).

[0209] The sample was scanned at the corners with the microscope, and the images were evaluated using the VK-X3000 multi-file analyzer program. This program allows distance measurements to be made at selected points on the scanned sample surface. The at least partially cured region of the adhesive layer activated by irradiation is visibly detached from the uncured region due to turbidity, as the adhesive becomes optically visible (white) through activation.

[0210] The degree of chemical conversion (conversion rate) was determined by ATR-FTIR (Attenuated Total Reflection (ATR); Fourier Transform Infrared Spectroscopy (FTIR)).

[0211] For this purpose, the relevant area was placed on the ATR crystal and the epoxide signal in the range of ~925 cm -1 was evaluated in comparison to non-irradiated (0% conversion rate) and fully cured samples (100% conversion rate).

[0212] Since the relevant area was significantly narrower than the measurement range of ATR-FTIR, multiple optically altered edge areas were cut from the tape in the x-direction and placed side by side on the ATR crystal. The measurement was carried out three days after activation. By irradiating with a UV LED of 7000 mJ / cm 2 and then curing for 3 days at 23°

[0213] C / 50% r.F. (relative humidity), a fully cured reference sample was produced.

[0214] Adhesive overflow ("bleeding")

[0215] Regarding adhesive overflow ("bleeding"), the samples were also evaluated after storage at 23 °C and 50% r.F. for 28 days, and the following categories listed in Table 1 were defined for this purpose:

[0216] Table 1:

[0217] Category Definition Number of drops 0 No adhesive spillage 0 1 Adhesive spillage in the form of drops ≤10 2 Adhesive spillage in the form of drops 11≤50 3 Adhesive spillage in the form of drops >50 4 Surface (sheet) adhesive spillage Uncountable

[0218] Table 1 shows that the increase in adhesive overflow is related to the increase in categories.

[0219] Table 2:

[0220]

[0221] The examples show that even passivation of ~200 μm can achieve a significant reduction in adhesive overflow (V3). V1 and V2 show very strong adhesive overflow. If the activated edge area is larger than 200 μm (E1 to E3), no adhesive overflow can be observed anymore. With the help of ATR-FTIR, an epoxy resin conversion rate of more than 50% can be measured in the activated area.

[0222] Since side edge passivation logically results in narrow edges with reduced adhesion, the individual maximum width of the activation area must be determined for each application.

[0223] In the reference experiment, a very wide activation area of 832 μm could be produced with a longer irradiation time.

[0224] Compared with E2, it shows that when pasting the edge of a rectangular aluminum block with a 1 mm strip on the edge side, the activation area is already too large, and the restoring force is stronger than the remaining adhesive force, so that the activated paste

[0225] The edge of the tape or the 1 mm wide strip detaches from the aluminum block. This cannot be observed for E1 to E3, and also cannot be observed for V1 to V3.

[0226] The bonding strength of the transfer tape (lap joint) according to the present utility model is all independent of the side edge passivation, unaffected in the middle region and greater than 7 MPa. Description of the Drawings

[0227] Hereinafter, the preferred embodiments of the present utility model will be further explained and described with reference to the drawings. Here:

[0228] Figure 1 is a cross-sectional view of the tape according to the present utility model viewed from the z direction.

[0229] In Figure 1 , the tape 1 has a width 2, which corresponds to the extension of the tape in the y direction. The extension of the tape in the x direction corresponds to the direction in which the tape can be wound into a roll.

[0230] The tape has a first outer edge 3 and a second outer edge 4 in the y direction.

[0231] The tape is shown in a top view from the z direction. There is a layer of reactively curable adhesive in the x, y plane. This is, for example, the adhesive used above for Examples E1 to E3 according to the present utility model.

[0232] The tape is treated as described above at the outer edges 3 and 4, in particular and for example by UV irradiation, also exemplarily as described above.

[0233] Thereby, the reactively curable adhesive of the treated tape is activated at the outer edges 3 and 4 respectively, whereby the adhesive in the width 2 has different regions, namely the corresponding edge regions 3a and 4a (where the reactively curable adhesive is cured to at least 30%), and the middle region 5 (which has not undergone irradiation and where the chemical conversion of the reactive components has occurred by 0%).

[0234] The edge regions 3a and 4a each have a width 3b or 4b in the y direction of more than 200 μm.

[0235] Figure 1 The illustration in

[0236] List of Reference Numerals:

[0237] 1 Adhesive tape according to the present utility model

[0238] 2 Width of the adhesive tape in the y direction

[0239] 3 First outer edge

[0240] 3a First edge region where the adhesive is activated

[0241] 3b Width of the first edge region in the y direction

[0242] 4 Second outer edge

[0243] 4a Second edge region where the adhesive is activated

[0244] 4b Width of the second edge region in the y direction

[0245] 5 Intermediate region

Claims

1. A reactive adhesive tape having a width (2) corresponding to the extent of the adhesive tape in the y direction and having a first outer edge (3) and a second outer edge (4) in the y direction, comprising at least one layer of a reactively curable adhesive comprising a reactive component, wherein curing takes place by chemical conversion of the reactive component, characterized in that The adhesive layer has, in the y direction, at the first and second outer edges (3, 4), respectively an edge region (3a, 4a) and a middle region (5) arranged between the edge regions, wherein the edge regions (3a, 4a) are optically different from the middle region (5).

2. The reactive adhesive tape according to claim 1, characterized in that The edge regions (3a, 4a) differ from the central region (5) by a higher viscosity, wherein the edge regions (3a, 4a) in each case have a higher viscosity than the central region (5).

3. The reactive adhesive tape according to claim 1 or 2, characterized in that: The edge regions (3a, 4a) differ from the central region (5) by a different colour and / or a different turbidity.

4. The reactive adhesive tape according to claim 1 or 2, characterized in that: The adhesive is pressure-sensitive at least in the middle region (5).

5. The reactive adhesive tape according to claim 1 or 2, characterized in that: Each edge region ( 3 a , 4 a ) has a width ( 3 b , 4 b ) in the y direction of greater than 200 μm and up to 800 μm.

6. The reactive adhesive tape according to claim 5, characterized in that Each edge region ( 3 a , 4 a ) has a width ( 3 b , 4 b ) in the y direction of 250 μm to 750 μm.

7. The reactive adhesive tape according to claim 6, characterized in that Each edge region ( 3 a , 4 a ) has a width ( 3 b , 4 b ) in the y direction of 300 μm to 600 μm.

8. The reactive adhesive tape according to claim 1, characterized in that It furthermore has at least one carrier layer.

9. The reactive adhesive tape according to claim 8, characterized in that The carrier layer comprises a foil.

10. The reactive adhesive tape according to claim 9, characterized in that The foil comprises polyethylene terephthalate (PET).

11. The reactive adhesive tape according to claim 8 or 9, characterized in that It is a single-sided tape.

12. The reactive adhesive tape according to claim 1 or 2, characterized in that: It is present in the form of a roll of adhesive tape, wherein the y direction corresponds to the axial direction of the roll of adhesive tape.

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