Reactive adhesive tape

Abstract

The invention relates to a reactive curable adhesive tape, to a method for producing a reactive curable adhesive tape having a passivated side edge, and to the use thereof. The invention relates to a reactive curable adhesive tape having a width corresponding to the extension of the adhesive tape in the y-direction and having a first outer edge and a second outer edge in the y-direction and comprising at least one layer of a reactive curable adhesive comprising a reactive component, the curing being carried out by a chemical conversion of the reactive component, the adhesive layer has an edge region on the first outer edge and on the second outer edge in the y-direction and an intermediate region arranged between the edge regions, in each case a chemical conversion of the reactive component of the adhesive in the edge region takes place at an extent of at least 30% and at a higher extent than in the intermediate region, and the chemical conversion is preferably carried out in the intermediate region to an extent of 0 to 10%, particularly preferably 0 to 5%, particularly 0%, each edge region having a width in the y-direction greater than 200 [mu] m.

Description

Technical Field

[0001] The present invention relates to a reactively curable adhesive tape, a method for producing a reactively curable adhesive tape with side-edge passivation, and the use of a reactively curable adhesive tape. Background Art

[0002] Reaction-curing, in particular room-temperature-curing, pressure-sensitive adhesive tapes (for example based on the polymerization of acrylate monomers) have been developed over several years and have reached a high level of maturity.

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

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

[0005] EP 4242277 A1 discloses a UV-curable adhesive based on polymerizable epoxide compounds which polymerize cationically by activation with a cationic photoinitiator.

[0006] Unlike liquid reactive adhesives, reactively curable (or simply "reactive") adhesive tapes must possess a certain degree of cohesion before activation in order to be pressure-sensitively adhesive. It has been shown that balancing sufficient cohesion to produce a good pressure-sensitive adhesive state before activation and achieving high bond strength after activation is challenging. This is due to the fact that changes in cohesion have opposing effects on the properties in the uncured state and the bond strength after activation. In the prior art, there are many instructions on how to modify the formulation of reactive pressure-sensitive adhesive films to improve bleed (cold flow) properties while still achieving high bond strength.

[0007] WO 2017117163 A1 describes a method in which a slurry is first prepared and then, after application, crosslinked and polymerized at a certain wavelength without triggering the curing reaction of the second reactive component. This only occurs when the adhesive tape is applied, by irradiation with a second wavelength.

[0008] US 9109142 B2 discloses specific grafted polymers intended to reduce exudation.

[0009] US 11377576 B2 discloses that certain film-forming polymers reduce exudation because the epoxide is "retained".

[0010] WO 2023037185 A1 discloses methacrylate block copolymers intended to reduce exudation.

[0011] However, in all cases the formulation is disturbed, thereby negatively affecting the properties in the cured state.

[0012] Therefore, there is still the problem that adhesive tapes or adhesive tape rolls designed for high bond strength have an undesirable cold flow of the adhesive before the application and curing of the corresponding adhesive. This can lead in particular to lateral (transverse) overflow of the adhesive tape or adhesive tape roll, making storage and transportation quite difficult. Summary of the Invention

[0013] It was therefore an object of the present invention to provide reactively curable adhesive tapes which do not exhibit any leakage of adhesive in the unbonded state and which at the same time still have an optimal bond strength after bonding.

[0014] This object is achieved according to the invention by an adhesive tape as defined in the invention.

[0015] The adhesive tape according to the invention has a width corresponding to the extent (dimension, extension) 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 reactively curable adhesive comprising a reactive component, wherein curing takes place by chemical conversion of the reactive component, and is characterized in that the adhesive layer has an edge region in the y direction at each of the first outer edge and the second outer edge 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 extent than in the intermediate region, and wherein each edge region has a width in the y direction of greater than 200 μm.

[0016] Since the adhesive in the edge regions has a higher degree of chemical conversion of reactive components than in the central region, cold flow of the adhesive in the edge regions is suppressed and undesirable adhesive overflow at the outer or side edges is avoided. At the same time, the adhesive can still be formulated as a reactive curing adhesive, achieving the optimal bond strength for the respective application without being adversely affected by changes or additional components.

[0017] Preferably, the chemical conversion in the central region does not occur at all or only to a minimal extent, and thus preferably to an extent of 0 to 10%, particularly preferably 0 to 5%, and in particular 0%. Consequently, the adhesive in the central region of the adhesive tape according to the invention remains uncured, ready for later application and cured bonding. In particular, the central region has not been subjected to any treatment, in particular no irradiation.

[0018] Preferably, the reactive components of the adhesive are chemically converted in the edge regions 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%. The conversion continues over time. An edge region that has, for example, a conversion of at least 50% after irradiation can, for example, have a conversion of 80% after one day.

[0019] According to the invention, it is therefore essential only that the conversion in the edge region takes place to an extent of at least 30%, or to a further preferred extent, in order to avoid overflow of the adhesive at the outer edge.

[0020] Particularly and preferably, the chemical conversion of the reactive components of the adhesive is carried out in the edge regions in each case to a certain extent, so that no longer adhesive overflows laterally from the adhesive tape. Here, the viscosity of the adhesive in the edge regions increases compared to the middle region.

[0021] The degree of chemical conversion is determined within the scope of the present invention, in particular, by suitable spectroscopic methods, by which the reactants can be determined qualitatively and, by comparison with references, quantitatively. A person skilled in the art will be able to identify the reactants suitable for the respective reactive chemistry and select the corresponding method for verification. A suitable method, and one preferred within the scope of the present invention, is ATR-FTIR (Attenuated Total Reflectance (ATR); Fourier Transform Infrared Spectroscopy (FTIR)), as described below. This method is particularly suitable for determining the conversion rate in the following cationic polymerizations with the participation of epoxide compounds and in the free-radical polymerization of acrylates.

[0022] All embodiments of this description apply to the adhesive tape according to the invention, the method according to the invention for producing the adhesive tape and the use of the adhesive tape according to the invention.

[0023] The present invention also includes all features as any preferred technical solution. Furthermore, the present invention includes combinations of features, and in such cases, includes different levels of preference. Thus, for example, the present invention also includes a combination of a first feature designated as "preferred" with a second feature designated as "particularly preferred." Similarly, objects designated within the scope of "embodiments" also include different levels of preference.

[0024] The invention relates to an adhesive tape. The adhesive tape according to the invention has a width corresponding to the extent of the adhesive tape in the y-direction and has a first outer edge and a second outer edge in the y-direction.

[0025] In principle, the adhesive tape can be present in any production form, with adhesive tape rolls being preferred.

[0026] The adhesive tape, in particular in web form, can be produced both in roll form (ie wound on itself in the manner of an Archimedean spiral) and as an adhesive strip, for example in the form of blanks or die-cut parts.

[0027] A web is understood to mean an object whose length (extension in the x-direction) is a multiple of its width (extension in the y-direction) and whose width is formed to be approximately identical along the entire length.

[0028] However, the invention should not be limited to the fact that the length in the x-direction is greater than the width in the y-direction.Thus, for example, square blanks according to the invention are also included.

[0029] Within the scope of the present invention, the definition of the y-direction is used only to describe the outer edges that are opposite to each other in one direction, at which the adhesive has other properties that are different from the rest of the tape, the middle area, so that no adhesive escapes from the tape due to cold flow (seepage).

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

[0031] The preferred shape of the blanks, die cuts and labels is rectangular.

[0032] Preferably, the adhesive tape according to the invention is in the form of an adhesive tape roll, wherein the y direction corresponds to the axial direction of the adhesive tape roll. The longitudinal extension then corresponds to the x direction or circumferential direction.

[0033] In particular, the adhesive tape roll has the advantage that there is no or virtually no outer edge in the x-direction over which adhesive could pass outwards.

[0034] In addition to a longitudinal extent (x-direction) and a width extent (y-direction), the adhesive tape also has a thickness perpendicular to the two extents (z-direction), wherein the width and longitudinal extents are many times greater than the thickness. The thickness is as constant as possible over the entire area defined by the length and width of the adhesive tape, preferably identical within a tolerance range.

[0035] The embodiments described apply analogously to the carrier layer, which forms a layer in the x and y direction as a component of the adhesive tape according to some preferred embodiments,

[0036] It will be understood that the various layers are arranged on top of each other along the z-direction, and that in the roll form the z-direction is the radial direction.

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

[0038] According to the invention, the edge regions have a width in the y-direction of greater than 200 μm.

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

[0040] According to an advantageous embodiment, the edge regions have a width in the y-direction of 250 μm to 750 μm, in particular of 300 μm to 600 μm.

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

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

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

[0044] Therefore, one aspect of the present invention also provides a reactively curable adhesive tape having a width corresponding to the extension of the tape in the y direction, and having a first outer edge and a second outer edge in the y direction, and comprising at least one layer of a reactively curable adhesive comprising a reactive component, wherein curing occurs by chemical conversion of the reactive component, wherein the adhesive layer has an edge region at each of the first and second outer edges in the y direction and an intermediate region arranged between the edge regions, wherein the edge region is optically different from the intermediate region.

[0045] In another aspect of the invention, the edge regions differ from the middle region in that they have a higher viscosity, which is caused in particular by a higher degree of chemical conversion in the edge regions.

[0046] In another aspect of the invention, the edge region differs from the middle region by a different color and / or a different turbidity.

[0047] According to the invention, this is a reactively curable adhesive tape which accordingly comprises at least one layer of a reactively curable adhesive, wherein the reactively curable adhesive comprises reactive components for the purpose of reactive curing and curing takes place by chemical conversion of the reactive components.

[0048] Such reactive adhesive layers are known to those skilled in the art as components of reactively curable adhesive tapes.

[0049] Therefore, within the scope of the present invention, a “reactively curable adhesive” is understood to mean an adhesive which cures by chemical reaction of at least one correspondingly contained reactive component, thereby producing an adhesive connection.

[0050] Within the scope of the present invention, such adhesives are also referred to as “reactive adhesives”.

[0051] The terms “reactively curable adhesive tape” and “reactive adhesive tape” are used synonymously within the scope of the present invention. This applies analogously to the adhesive and the adhesive layer.

[0052] Preferably, the reactively curable adhesive tape according to the invention or the corresponding reactive adhesive acts as a structural adhesive or semi-structural adhesive after curing.

[0053] According to DIN EN 923:2006-01, structural adhesives are clearly suitable for the production of load-bearing structures, where the adhesive bond can withstand a high percentage of the maximum breaking force for a long period of time without failure (according to the ASTM definition: "bonding agents used for transferring required loads between adherends exposed to service environments typical for the structure involved"). Therefore, they are adhesives used for chemically and physically high-stress bonds, which contribute to the strengthening of the tape in the cured state.

[0054] The term "(semi)structural adhesive" encompasses "semistructural adhesives" and "structural adhesives". "Semistructural adhesives" are understood to mean those cured adhesives which have a tensile shear strength in a tensile shear test of at least 1.0 MPa and preferably at least 1.5 MPa (in each case on steel). "Structural adhesives" are understood to mean those cured adhesives which have a particularly high tensile shear strength and have a tensile shear strength in a tensile shear test of at least 5 MPa, preferably at least 7 MPa and particularly preferably at least 10 MPa (in each case on steel).

[0055] The chemical reaction takes place in particular after activation, for example by heat, moisture, plasma or in particular irradiation (radiation).

[0056] Within the scope of the present invention, preference is given to reactively curable adhesive tapes in which curing occurs by activation of a chemical reaction or chemical conversion by irradiation, in particular by light of a wavelength in the visible range of the electromagnetic spectrum or by UV light.

[0057] In principle, the reactively curable adhesive may be any reactively curable adhesive known to the person skilled in the art.

[0058] As understood by those skilled in the art, the components defined within the scope of the present invention are used in each case as "one or more." The term "one or more" here refers to the chemical nature of the corresponding compound, rather than the amount of substance, in the manner commonly used in the industry. For example, a curable adhesive that is a polymerizable epoxide compound may include only epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate, which means that the curable adhesive includes a plurality of corresponding molecules.

[0059] In an industry-standard manner, the mass fractions are expressed here as the combined mass fraction of one or more components, thereby indicating that the mass fractions of the respectively formed components together meet the corresponding standard, wherein in the absence of further information, the mass of the curable adhesive in each case is the reference system.

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

[0061] Preference is given to adhesive tapes according to the invention in which the reactively curable adhesive contains at least one photoactivatable substance which initiates a chemical conversion of the reactive components by activation with UV or visible light, and in which the chemical conversion of the reactive components of the adhesive in the edge region is carried out by irradiating the outer edge with UV or visible light of the wavelength required for activation of the photoactivatable substance.

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

[0063] Particularly preferred are adhesive tapes according to the invention in which the reactively curable adhesive contains at least one photoinitiator for initiating cationic polymerization or at least one photoredox system for initiating free-radical polymerization, and the wavelength of the visible or UV light is selected such that it corresponds to the activation wavelength of the photoinitiator or the photoredox system.

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

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

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

[0067] The photoredox system within the scope of the present invention comprises, in particular, c) at least one initiator and d) at least one photoredox catalyst.

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

[0069] In the context of the present invention, the term "redox catalyst" denotes a compound which can mediate the transfer of electrons between compounds which would otherwise react more slowly or not at all.

[0070] For the purposes of the present invention, the term "photoredox catalyst" refers to a light- or UV-sensitive compound that, when excited by light or UV light, mediates electron transfer between compounds that would otherwise react more slowly or not at all. In contrast to the photoinitiators disclosed, for example, in EP 3910715A1, photoredox catalysts do not decompose into reactive fission products upon irradiation with light or UV light, but rather only assume an excited state, which is generally relatively long-lived and can initiate or mediate redox processes. At temperatures up to 90°C, photoredox catalysts preferably do not initiate polymerization in mixtures with free-radically polymerizable monomers or oligomers, even when the mixture is irradiated with UV or blue light. This applies as long as no free-radical initiators or other initiating substances are added to the mixture.

[0071] Therefore, photoredox catalysts are not initiators or free radical generators. When irradiated with UV or blue light, they simply activate the initiator, which then initiates polymerization. This delayed mechanism results in the so-called open time, during which the adhesive tape can still be applied before reactive curing begins.

[0072] Photoredox catalysts and initiators that can initiate curing immediately, such as by light activation or thermal activation, are not initiators within the scope of the present invention.

[0073] Preferably, the initiator is a free radical initiator, wherein mixtures of two or more initiators are conceivable. 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 invention, the free radical initiator is an organic peroxide. Particularly preferred is a hydroperoxide, in particular diisopropylbenzene hydroperoxide (or diisopropylbenzene hydroperoxide) (CAS No. 26762-93-6). Diisopropylbenzene hydroperoxide is preferably used in the form of a 50% by weight solution of diisopropyl hydroperoxide in diisopropylbenzene, sold under the trade name IHP-50 can be obtained. 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 initiators, preferably free radical initiators (which are preferably selected from hydroperoxides), in the curable adhesive is 0.1% to 9%, particularly preferably 0.1% to 5%, and 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 being not consumed during the reaction.

[0077] Photoredox catalysts known to those skilled in the art can be used as photoredox catalysts. Photoredox catalysts are typically transition metal complexes with ruthenium, copper or iridium as central atoms (depending on the ligand, it is neutral or present in cationic form). Bidentate ligands can preferably be used as ligands for transition metal complexes, in particular those with at least two interconnected heteroaromatic six rings, for example in the form of biphenyl, which can in turn 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 the "teeth" of the ligand, thereby obtaining bidentate properties. The bicyclic aromatic compound, such as a biphenyl compound, or the polycyclic aromatic compound used as a 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.

[0078] According to a preferred embodiment of the present invention, the photoredox catalyst is a transition metal complex having ruthenium as a central atom and bipyridine or a mono- or poly-substituted bipyridine derivative as a ligand.

[0079] In another preferred embodiment of the present invention, the photoredox catalyst is a transition metal complex having iridium as a central atom and phenylpyridine or a mono- or polysubstituted phenylpyridine derivative as a ligand.

[0080] Therefore, the reactive adhesive tape according to the invention according to the aforementioned embodiment is also preferred, characterized in that the photoredox catalyst comprises ruthenium as a central atom and bipyridine or a monosubstituted or polysubstituted bipyridine derivative as a ligand, or iridium as a central atom and phenylpyridine or a monosubstituted or polysubstituted phenylpyridine derivative as a ligand.

[0081] Preferably, at least one photoredox catalyst is selected from: Ru(bpm) 2+ (e.g. tris(2,2′-bipyrimidinyl)ruthenium(II) dichloride), Ru(bpz)3 2+(e.g. tris(2,2'-bipyrazine)bis(hexafluorophosphate)ruthenium), Ru(bpy)3 2+ 、Ru(phen)3 2+ (e.g. dichlorotris(1,10-phenanthroline)ruthenium(II) chloride), Ir[dF(CF3)ppy]2(dtbbpy) + (e.g., [4,4′-bis(1,1-dimethylethyl)-2,2′-bipyridyl-N1,N1′]bis[3,5-difluoro-2-[5-(trifluoromethyl)-2-pyridyl-N]phenyl-C]iridium(III) hexafluorophosphate), Ir(ppy)2(dtbbpy) + (e.g. [Ir(dtbbpy)(ppy)2][PF6]), in each case with the addition of one or more anions (or counterions to the cations), 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).

[0082] According to a particularly preferred embodiment of the present invention, the photoredox catalyst is tris(2,2′-bipyridyl)ruthenium(II) chloride hexahydrate Ru(bpy) 3 Cl 2 ·6H 2 O.

[0083] According to a preferred embodiment, the combined mass fraction of the photoredox catalyst in the curable adhesive is up to 1%, particularly preferably 0.01% to 0.5%, and particularly preferably 0.01 to 0.1%, based on the mass of the curable adhesive.

[0084] Systems based on polymerizable epoxide compounds, which polymerize cationically by activation with cationic photoinitiators, are, as mentioned at the outset, also known to the person skilled in the art and are disclosed, for example, in EP 4242277 A1.

[0085] The person skilled in the art adjusts the catalyst system used for the curing essentially as a function of the application requirements, in particular the wavelength provided for activation of the subsequent curing, and the polymerizable epoxide compound used.

[0086] As initiators for this curing based on cationic radiation (ie generally UV-induced) of epoxide compounds, it is possible in particular to use systems based on sulfonium, iodonium and metallocenes.

[0087] For examples of sulfonium-based cations, reference is made to the description in US Pat. No. 6,908,722 B1.

[0088] Examples of anions used as the counterions of the above-mentioned cations include tetrafluoroborate, tetraphenylborate, hexafluorophosphate, perchlorate, tetrachloroferrate, hexafluoroarsenate, hexafluoroantimonate, pentafluorohydroxyantimonate, hexachloroantimonate, tetrakispentafluorophenylborate, tetrakis(pentafluoromethylphenyl)borate, bis(trifluoromethanesulfonyl)amide, and tris(trifluoromethanesulfonyl)methyl. In addition, particularly for iodonium-based initiators, chloride, bromide, or iodide may also be contemplated as anions, although initiators that are 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.

[0089] Specific examples of sulfonium salts which can be used are, in particular, triarylsulfonium salts which may be substituted by acetyl or methyl groups, for example, triarylsulfonium hexafluorophosphate, triarylsulfonium tetrakispentafluorophenylborate, triphenylsulfonium hexafluoroarsenate, triphenylsulfonium hexafluoroborate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium tetrakis(pentafluorobenzyl)borate, methyldiphenylsulfonium tetrafluoroborate, methyldiphenylsulfonium tetrakis(pentafluorobenzyl)borate, dimethylphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, diphenylnaphthylsulfonium hexafluoroarsenate, triphenylsulfonium tetrafluoroborate, tri ... triphenylsulfonium tetrafluorophosphate, triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, diphenylnaphthylsulfonium hexafluoroarsenate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium tetrakis(pentafluorobenzyl)borate, triphenylsulfonium tetrafluorophosphate, triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, diphenylnaphthylsulfonium hexafluoroarsenate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium tetrakis(pentafluorobenzyl)borate, triphenylsulfonium tetrafluorophosphate, triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, diphenylnaphth Tolylsulfonium hexafluorophosphate, methoxyphenyldiphenylsulfonium hexafluoroantimonate, 4-butoxyphenyldiphenylsulfonium tetrafluoroborate, 4-chlorophenyldiphenylsulfonium hexafluoroantimonate, tris(4-phenoxyphenyl)sulfonium hexafluorophosphate, bis(4-ethoxyphenyl)methylsulfonium hexafluoroarsenate, 4-acetylphenyldiphenylsulfonium tetrafluoroborate, 4-acetylphenyldiphenylsulfonium tetrakis(pentafluorobenzyl)borate, tris(4-thiomethoxyphenyl)sulfonium hexafluorophosphate, bis(methoxysulfonylphenyl)methylsulfonium hexafluoroantimonate, bis(methoxynaphthyl)methylsulfonium tetrafluoroborate , bis(methoxynaphthyl)methylsulfonium tetrakis(pentafluorobenzyl)borate, bis(methylcarbophenyl)methylsulfonium hexafluorophosphate, (4-octyloxyphenyl)diphenylsulfonium tetrakis(3,5-bistrifluoromethylphenyl)borate, tris[4-4-(acetylphenyl)thiophenyl]sulfonium tetrakis(pentafluorophenyl)borate, tris(dodecylphenyl)sulfonium tetrakis(3,5-bistrifluoromethylphenyl)borate, 4-acetamidophenyldiphenylsulfonium tetrakis(pentafluorobenzyl)borate, dimethylnaphthylsulfonium hexafluorophosphate, trifluoromethyl Diphenylsulfonium tetrafluoroborate, trifluoromethyldiphenylsulfonium tetrakis(pentafluorobenzyl)borate, phenylmethylbenzylsulfonium hexafluorophosphate, 5-methylthianthrenium hexafluorophosphate, 10-phenyl-9,9-dimethylthianthrenium hexafluorophosphate, 10-phenyl-9-oxythianthrenium tetrafluoroborate, 10-phenyl-9-oxythianthrenium tetrakis(pentafluorobenzyl)borate, 5-methyl-10-oxythianthrenium tetrakis(pentafluorobenzyl)borate, and 5-methyl-10,10-dioxythianthrenium hexafluorophosphate.

[0090] Specific examples of iodonium salts that can be used are diphenyliodonium tetrafluoroborate, bis(4-methylphenyl)iodonium tetrafluoroborate, phenyl-4-methylphenyliodonium 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-thienyliodonium hexafluorophosphate, 3,5-dimethylpyrazolyl-4-phenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, 2,2′-diphenyliodonium tetrafluoroborate, bis(2,4-dichlorophenyl)iodonium hexafluorophosphate, phosphate, 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 tristrifluoromethanesulfonylmethides such as diphenyliodonium hexafluoroantimonate, diaryliodonium tetrakis(pentafluorophenyl)borates such as diphenyliodonium tetrakis(pentafluorophenyl)borates, [4-2-(hydroxy-n-tetradesiloxy)phenyl]phenyliodonium hexafluoroantimonate, [4-(hydroxy-n-tetradesiloxy)phenyl ... [4-2-(Hydroxy-n-tetradecyloxy)phenyl]phenyliodonium trifluorosulfonate, [4-2-(Hydroxy-n-tetradecyloxy)phenyl]phenyliodonium hexafluorophosphate, [4-2-(Hydroxy-n-tetradecyloxy)phenyl]phenyliodonium tetrakis(pentafluorophenyl)borate, bis(4-tert-butylphenyl)iodonium hexafluoroantimonate, bis(4-tert-butylphenyl)iodonium hexafluorophosphate, bis(4-tert-butylphenyl)iodonium trifluorosulfonate, bis(4-tert-butylphenyl)iodonium tetrafluoroborate, bis(dodecylphenyl)iodonium hexafluoroantimonate, bis(dodecylphenyl)iodonium tetrafluoroborate, bis(dodecylphenyl)iodonium hexafluorophosphate, bis(dodecylphenyl)iodonium trifluoromethanesulfonate, di(dodecylphenyl)iodonium hexafluoroantimonate, di(dodecylphenyl)iodonium trifluoromethanesulfonate, diphenyliodonium hydrogen sulfate, 4,4'-dichlorodiphenyliodonium hydrogen sulfate, 4,4'-dibromodiphenyliodonium hydrogen sulfate, 3,3'-dinitrodiphenyliodonium hydrogen sulfate, 4,4'-dimethyldiphenyliodonium hydrogen sulfate, 4,4'-disuccinimidyldiphenyliodonium hydrogen sulfate, 3-nitrodiphenyliodonium hydrogen sulfate, 4,4'-dimethoxydiphenyliodonium hydrogen sulfate, bis(dodecylphenyl)iodonium tetrakis(pentafluorophenyl)borate, (4-octyloxyphenyl)phenyliodonium tetrakis(3,5-bistrifluoromethylphenyl)borate and tolylcumyl)iodonium tetrakis(pentafluorophenyl)borate; and ferrocenium salts (see, for example, EP 0 542 716 B1), for example n 5-(2,4-cyclopentadien-1-yl)[1,2,3,4,5,6,9)-(1-methylethyl)phenyl]iron.

[0091] Such cationic photoinitiators are generally used alone or in combinations of two or more photoinitiators. For example, when using a photoinitiator, the combination with a so-called sensitizer for adapting the activation wavelength of the photoinitiating system to the selected emission spectrum is particularly helpful for prior art curable adhesives, as disclosed, for example, in the AW Green textbook "Industrial Photoinitiators: A technical guide" 2010.

[0092] Some cationic photoinitiators, such as those commercially available under the trade name Deuteron UV 1242, react only within a relatively short wavelength range of 220 to 250 nm. Activation with the aid of typical UV LEDs, which might be highly preferred from an application-related perspective, is not possible or at least not effective here, since the emission maximum of typical UV LEDs is at a wavelength of approximately 365 nm. To activate these cationic photoinitiators with typical UV LEDs, the concept of "free radical accelerator cationic curing," as described in the literature, is used. To this end, a free radical initiator is added as a sensitizer, such as those commercially available under the trade names Omnirad BDK or Irgacure 651, which decays upon excitation with higher wavelengths (e.g., 365 nm, typical for UV LEDs). The free radicals or other reactive species formed in this way activate the cationic initiator, which ultimately initiates the curing of the epoxide compound. Typically, 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 here is generally not more than 3% and is preferably in the range from 0.5% to 2%.

[0093] In the context of the present invention, the reactively curable adhesive particularly preferably comprises at least one photoinitiator for initiating cationic polymerization. The cationic photoinitiator is preferably selected from the aforementioned group and in particular from sulfonium salts and iodonium salts.

[0094] 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.

[0095] In a particularly advantageous embodiment, the cation of the photoinitiator is selected from acetyl- or methyl-substituted triarylsulfoniums, which are 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 diaryliodoniums, which are commercially available, for example, under the names Omnicat 250 (IGM resins), Speedcure 939, Speedcure 938, Speedcure 937 (Arkema), Deuteron 1240, Deuteron 1242 (Deuteron).

[0096] According to a particularly advantageous embodiment, at least one sulfonium salt is used as cationic photoinitiator, for example and in particular acetyl-substituted triarylsulfonium hexafluorophosphate (CAS: 953084-13-4) or acetyl-substituted triarylsulfonium tetrakispentafluorophenylborate or tris(4-(4-acetylphenyl)thiophenyl)sulfoniumtetrakis(pentafluorophenyl)borate.

[0097] Preference is given to adhesive tapes according to the invention in which the reactively curable adhesive comprises at least the following components:

[0098] a) at least one polymer; and

[0099] b) at least one reactive resin; and

[0100] c) at least one photoinitiator for initiating cationic polymerization or at least one photoredox system for initiating free-radical polymerization.

[0101] For component c), all previous embodiments apply, preferably including at least one photoinitiator for initiating cationic polymerization.

[0102] The at least one reactive resin represents, in particular, the reactive component of the reactively curable adhesive.

[0103] In the case of at least one photoinitiator for initiating cationic polymerization, components a) and b) and additives are preferred.

[0104] Suitable polymers a) and reactive resins b) for cationic or free-radical polymerization are known to those skilled in the art.

[0105] In the case of cationic polymerization, the reactively curable adhesive preferably comprises one or more (co)polymers as polymer component a).

[0106] The person skilled in the art understands that (co)polymers generally act as film formers, which is particularly important since the intention is in particular to obtain pressure-sensitive adhesives. Preferably, the one or more (co)polymers are selected from the group consisting of 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 from the group consisting of 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)), in particular from the group consisting of poly(meth)acrylates, phenoxy polymers and ethylene-vinyl acetate copolymers.

[0107] Additionally or alternatively, as (co)polymers, block copolymers, such as (meth)acrylate block copolymers, may also be used. Corresponding examples are disclosed, for example, in US 2011003947 A1, US 20080200589 A1, US 2007078236 A1, US 2007078236 A1, US 2012196952 A1, US 2016032157 A1, US 2008146747 A1, and US 2016230054 A1.

[0108] According to a particularly advantageous embodiment, at least one olefin-vinyl ester copolymer is contained as (co)polymer a).

[0109] In particular, olefin-vinyl ester copolymers having a relatively high vinyl ester fraction are preferred, since the corresponding olefin-vinyl ester copolymers advantageously achieve a low crystallinity, which has proven to be particularly advantageous in the inventors' experiments. Preferably, at least one olefin-vinyl ester copolymer is an ethylene-vinyl ester copolymer having a vinyl ester fraction of 60% or more, in particular 70% or more, based on the mass of the (co)polymer.

[0110] The ethylene-vinyl ester copolymer is preferably an ethylene-vinyl acetate copolymer (EVA) having a vinyl acetate fraction of 60% or more, preferably 70% or more, based on the mass of the (co)polymer. Suitable ethylene-vinyl acetate copolymers are sold under the trade name HYDROGEN® 700 was obtained from Arlanxeo and had a vinyl acetate content of 70% by weight.

[0111] 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. Number average molar mass M n The figures are based on determinations by gel permeation chromatography (GPC). 100 μl of the clarified filtered sample (sample concentration 4 g / l) were determined. The eluent used was tetrahydrofuran with 0.1% by volume of trifluoroacetic acid. The measurements were carried out at 25° C. The precolumn used was a PSS-SDV type column, 5 μm, 8.0mm*50mm (the information here and below is in the following order: type, particle size, porosity, inner diameter*length; ). Separation was performed using a combination of PSS-SDV columns, 5 μm, as well as and Each column was 8.0 mm x 300 mm (columns from Polymer Standards Service; detection was performed using a Shodex RI71 differential refractometer). The flow rate was 1.0 ml / min. Calibration was performed using the commercially available ReadyCal-Kit Poly(styrene) high from PSS Polymer Standard Service GmbH, Mainz, or Agilent. In the case of polyacrylates, calibration was performed against PMMA standards (polymethyl methacrylate calibration), and in the case of other resins (resins, elastomers), calibration was performed against PS standards (polystyrene calibration).

[0112] Regardless of the specific choice of (co)polymer, it is preferred that 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.

[0113] Within the scope of the present invention, “reactive resin” is understood to mean a polymerizable compound.

[0114] According to the skilled person's understanding, the expression "polymerizable" here refers to the ability of these compounds to enter into a polymerization reaction, where appropriate after suitable activation. In the case of polymerizable epoxide compounds, the polymerizability is achieved, for example, via the epoxide group.

[0115] In the case of cationic polymerization, the reactively curable adhesive comprises one or more reactive resins b), which preferably comprise at least one compound selected from the group consisting of epoxide compounds, vinyl ethers and oxetanes.

[0116] Particularly preferably, the reactive resin(s) b) is / are at least one polymerizable epoxide compound in the case of cationic polymerization.

[0117] According to the skilled person's understanding, an epoxide compound is a compound carrying at least one ethylene oxide group.

[0118] Preferred are adhesive tapes according to the invention, wherein the reactively 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 are curable adhesive tapes according to the invention, wherein the reactively 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 2000 g / mol or less, as measured by GPC.

[0119] The polymerizable epoxide compound may be, for example, aromatic or aliphatic, more particularly cycloaliphatic in nature. The polymerizable epoxide compound often has an average of at least two epoxide groups per molecule, preferably greater than two epoxide groups per molecule. Preferably, the one or more polymerizable epoxide compounds are selected from epoxide compounds having two or more epoxide groups, preferably two epoxide groups.

[0120] Exemplary polymerizable epoxide compounds include epoxycyclohexanecarboxylates, 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. Additional polymerizable epoxide compounds that are particularly useful in the application of the present invention include glycidyl ether monomers, such as those disclosed, for example, in US 3,018,262. Examples are glycidyl ethers of polyphenols, obtained by reacting a polyphenol with an excess of a chlorohydrin, such as epichlorohydrin (e.g., diglycidyl ether of 2,2-bis(2,3-epoxypropoxyphenol)propane). In particular, 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 states of aggregation (e.g., so-called BADGE resins of types 1 to 10). Typical examples of liquid bisphenol-A diglycidyl ethers are Epikote 828, DER 331, Araldite GY 250CH and Epon 828. Typical solid BADGE resins are Araldite GT 6071, GT 7072, Epon 1001 and DER 662. Other reaction products of phenols with epichlorohydrin are phenol and cresol novolac resins, such as the Epiclon products or the Araldite EPN and ECN products (e.g., ECN 1273).

[0121] Here, it is preferred that the one or more polymerizable epoxide compounds are selected from epoxide compounds having at least one cycloaliphatic group, more particularly a cyclohexyl group or a dicyclopentadienyl group. Additionally or alternatively, it is preferred that the one or more polymerizable epoxide compounds are selected from bisphenol-A diglycidyl ether and bisphenol-F diglycidyl ester, preferably bisphenol-A diglycidyl ether.

[0122] According to the inventors, particularly advantageous curable adhesives can be obtained by using two or more different polymerizable epoxide compounds, in particular if they differ in their state of aggregation at room temperature. Preferably, the curable adhesive comprises one or more polymerizable epoxide compounds selected from epoxide compounds that are solid or have a high viscosity at 25° C. of 50 Pa s or more, preferably 100 Pa s or more, particularly preferably 150 Pa s or more, and / or the curable adhesive comprises one or more polymerizable epoxide compounds selected from epoxide compounds that are liquid at 25° C. of 40 Pa s or less, preferably 20 Pa s or less, very preferably 10 Pa s or less. Within the scope of the present invention, the dynamic viscosity is determined in accordance with DIN 53019-1, 2008; at 25° C., the dynamic viscosity is measured in 1 s -1 shear rate.

[0123] Regardless of the specific choice of polymerizable epoxide compound, it is preferred that the combined mass fraction of the polymerizable epoxide compound 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.

[0124] As other component, curable adhesive preferably comprises at least a epoxy-modified acrylonitrile-butadiene rubber.Epoxy-modified acrylonitrile-butadiene rubber is especially liquid, normally high viscosity polymer epoxy resin, it has the basic skeleton by forming with the acrylonitrile-butadiene rubber of epoxide group modification, described epoxide group is by introducing with epoxy resin or epoxide prepolymer modification, wherein the mass fraction of acrylonitrile-butadiene rubber is preferably in 5 to 50% scope, particularly preferably in 10 to 40 scope, very particularly preferably in 10 to 25% scope, based on the quality of epoxy-modified acrylonitrile-butadiene rubber.According to the understanding of technician, therefore statement " epoxy-modified acrylonitrile-butadiene rubber " refers to the conversion product of optional functionalized acrylonitrile-butadiene rubber and epoxy resin.In order to realize with the good miscibility of relative polar epoxy resin or epoxide prepolymer, the acrylonitrile-butadiene rubber polymer that epoxy-modified acrylonitrile-butadiene rubber is based on comprises at least 20% and maximum 50% acrylonitrile mass fraction, and particularly acrylonitrile mass fraction is in 25% to 40% scope. The term "nitrile rubber" is known to those skilled in the art and refers to butadiene-acrylonitrile copolymers. To attach epoxide groups to butadiene-acrylonitrile copolymers, one or more additional monomers with functional groups, such as carboxylic acid groups, such as acrylic acid, may be copolymerized during production. Carboxylic acid and nitrile rubber, for example, yield so-called carboxyl-terminated nitrile rubber (CTBN) or carboxylated nitrile rubbers as precursors for epoxy-modified nitrile rubbers, wherein the carboxylic acid groups may also or alternatively be present in the polymer chain. CTBN is also commercially available and is offered, for example, by BF Goodrich under the trade name Hycar. These have weight-average molar masses ranging from 2000 to 5000 g / mol and acrylonitrile contents ranging from 10 to 30%. Specific examples are Hycar CTBN 1300x8, 1300x13, or 1300x15. By reacting CTBN with epoxy resins or epoxide prepolymers, epoxy-modified nitrile rubbers, such as epoxy-terminated nitrile rubber (ETBN), can be obtained under suitable conditions. Such epoxy-terminated nitrile rubbers, in particular ETBN, are commercially available, for example, from Emerald Materials under the name HYPRO ETBN (formerly Hycar ETBN), for example under the trade names Hypro 1300X40 ETBN, Hypro 1300X63 ETBN and Hypro 1300X68 ETBN.Furthermore, such epoxy-modified nitrile rubbers are available from Schill+Seilacher "Struktol" GmbH 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-modified nitrile rubbers are sometimes also referred to as nitrile rubber-modified epoxy resins, where this designation is particularly a matter of perspective and, according to the inventors' estimation, is often based primarily on the mass fractions of the components converted together.

[0125] According to the estimation of the inventor, preferably, one or more epoxy-modified acrylonitrile-butadiene rubbers are selected from the epoxy-modified acrylonitrile-butadiene rubbers with 2 or larger, preferably 2.5 or larger, preferably especially 3 or larger average functionality.Additionally or alternatively, preferably, one or more epoxy-modified acrylonitrile-butadiene rubbers are selected from the epoxy-modified acrylonitrile-butadiene rubbers with terminal epoxy group and / or the epoxy group that is arranged in the chain.

[0126] According to the inventors' assessment, it is particularly preferred that the one or more epoxy-modified nitrile rubbers are selected from epoxy-modified nitrile rubbers having a weight-average molar mass Mw in the range of 5000 to 35000 g / mol, preferably in the range of 10000 to 30000 g / mol, particularly preferably in the range of 15000 to 25000 g / mol, as measured by GPC.

[0127] The inventor has found that surprisingly, particularly this epoxy-modified acrylonitrile-butadiene rubber causes the adhesive force of improvement, and it demonstrates at least one bimodal distribution in GPC.Under the situation that do not wish to be subject to this theoretical constraint, the inventor supposes that this has realized the balance between adhesive property and the cohesive property.For " at least bimodal () ", the inventor is interpreted as such GPC curve at this, and it comprises the mathematical derivation of an above maximum value or its molecular weight distribution and the x-axis intersect at least twice.Therefore preferably, one or more epoxy-modified acrylonitrile-butadiene rubbers are selected from the epoxy-modified acrylonitrile-butadiene rubber with at least bimodal weight-average molar mass distribution.

[0128] Since GPC results only provide relative information about molecular weights, and the quality of the measured values ​​and resolution depends strongly on the column type, the weight-average molar mass distribution, which is considered to be preferred, can be characterized relative to the peak with the highest molecular fraction. Particularly preferred are those epoxy-modified nitrile rubbers that exhibit at least two additional molar mass maxima in addition to the highest molecular peak in GPC. This specific molecular weight distribution can be achieved, for example, by converting CTBN with an epoxy resin (or reacting CTBN with an epoxy resin) and chain extension by adding diols or polyols, such as bisphenol A.

[0129] Additionally or alternatively, it is particularly preferred that the one or more epoxy-modified nitrile rubbers are selected from epoxy-modified nitrile rubbers having a weight-average molar mass Mw measured by GPC of greater than 2000 g / mol.

[0130] Regardless of the specific choice of epoxy-modified nitrile rubber, it is preferred that the combined mass fraction of the epoxy-modified nitrile rubber in the curable adhesive is in the range of 3.5 to 25%, preferably in the range of 4 to 20%, particularly preferably in the range of 4.5 to 18%, based on the mass of the curable adhesive.

[0131] As an advantage of the present invention, the reactive curable adhesive is very flexible with respect to the presence of other components, making it possible to advantageously tailor the physicochemical properties to the respective requirements of the application. For example, it is preferred that the curable adhesive include one or more polyols, preferably in a combined mass fraction of 0.5 to 15%.

[0132] Additionally or alternatively, it is also preferred that the curable adhesive comprises one or more further 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 wherein the one or more further additives are preferably selected from adhesive resins, ageing agents, light protection agents, UV absorbers, rheological additives and additives for increasing opacity.

[0133] In the case of at least one photoredox system for initiating free-radical polymerization, preferred components a) and b) and additives

[0134] In the case of free-radical polymerization, the reactively curable adhesive preferably also comprises one or more (co)polymers as polymer component a).

[0135] 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 acetate (PVA), polyacetals such as in particular polyvinyl butyral (PVB), polyesters and polymers formed from monomers including N-vinyl compounds.

[0136] Particularly preferred are polymers selected from the group consisting of ethylene-vinyl acetate copolymers (EVA), poly(meth)acrylates, poly(N-vinylcaprolactam), poly(N-vinylpyrrolidone) and polyurethanes (PU).

[0137] In the case of free-radical polymerization, the reactively curable adhesive comprises one or more reactive resins b), which preferably comprise at least one free-radically polymerizable monomer or oligomer.

[0138] According to the skilled person's understanding, a free-radically polymerizable monomer or oligomer shall mean a monomer or oligomer capable of free-radical chain polymerization.

[0139] A person skilled in the art understands that free-radically polymerizable oligomers, in particular as distinguished from polymers, are in particular free-radically polymerizable compounds having a weight-average molecular weight distribution Mw of less than 35,000 g / mol, in particular less than 15,000 g / mol, especially less than 10,000 g / mol, and within the scope of the present invention, in particular 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, in particular less than 15,000 g / mol, in particular less than 10,000 g / mol. These are, in particular, epoxy (meth)acrylates, aliphatic and aromatic silicone urethane (meth)acrylates, aliphatic and aromatic polyester (meth)acrylates, polybutadiene (meth)acrylates, dendritic (meth)acrylates, polyether (meth)acrylates and polycarbonate (meth)acrylamides, such as are obtainable from Miwon and Bomar, for example MIRAMER SC2565 with an Mw of 5200 g / mol from Miwon, or oligomers based on aliphatic polyurethanes, in particular on polyester-polyurethanes, such as are available under the trade name MIRAMER 8402, 48582 or 8809, or acrylated oligoesters based on caprolactone, such as the commercially available hydroxyethyl caprolactone acrylate (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 from 1 to 20, typically from 2 to 15, predominantly from 2 to 6. The dynamic viscosity at 25° C., measured in accordance with DIN 53019-1 from 2008, is preferably greater than 1 Pas, but particularly preferably significantly greater than 10 Pas. In particular, for the production of good pressure-sensitive adhesives with sufficient cohesion, oligomers are suitable as components of adhesives whose dynamic viscosity at 25° C. is greater than 20 Pas, preferably greater than 30 Pas. Within the scope of the present invention, the dynamic viscosity is measured in accordance with DIN 53019-1 from 2008; at 25° C., the dynamic viscosity is measured in 1 s -1 Shear rate determination.

[0140] According to a preferred embodiment, the at least one free-radically polymerizable monomer or oligomer has a boiling point of at least 30° C., preferably at least 60° C., and particularly preferably at least 80° C. at 1 mbar, or is present in solid form at 23° C. In this case, free-radically polymerizable oligomers are particularly preferred.

[0141] Suitable free-radically polymerizable monomers are selected from acrylates (e.g. 2-hydroxy-3-phenoxypropyl acrylate), methacrylates, vinyl compounds and compounds having carbon-carbon double bonds, and crosslinking free-radically polymerizable monomers such as diacrylates, dimethacrylates, triacrylates, trimethacrylates and higher-functional acrylates or higher-functional methacrylates.

[0142] Suitable free-radically polymerizable oligomers are, in particular, oligomeric substances having acrylate or methacrylate functionality or vinyl functionality, where the functionalization can be monofunctional or polyfunctional.

[0143] Preferably, in the free-radically polymerizable reactive adhesive variant of the reactive adhesive tape according to the invention, the weight ratio of total polymer to total free-radically polymerizable monomers or oligomers is 3:1 to 1:3, more preferably 2:1 to 1:2, in particular 2:1 to 1:1.

[0144] Additional additives and / or auxiliaries

[0145] In the case of free radical polymerization, the reactive curable adhesive may also contain additional additives and / or adjuvants known in the prior art. The combined mass fraction of additional additives and / or adjuvants may be in the range of 0 to about 20%, preferably 0 to 15%, more preferably 0 to 10%, and most preferably 0 to 5%, wherein the combined mass fraction is preferably at least 0.1% when additives are present. In each case, based on the mass of the curable adhesive,

[0146] As further additives and / or auxiliaries, there may be mentioned, for example, fillers, dyes, nucleating agents, rheological additives (for example fumed silica), blowing agents, adhesion enhancers (adhesion promoters, in particular silanes and tackifier resins), compounding agents, plasticizers and / or aging agents, light and UV protectants, for example in the form of primary and secondary antioxidants.

[0147] In particular and according to a preferred embodiment, fillers such as glass balls or The proportion of 5211 is up to 50% by mass, in particular up to 40% by mass.

[0148] According to a preferred embodiment, the free-radically polymerizable reactive adhesive comprises at least one rheology-modifying filler, for example silicon dioxide, particularly preferably in a combined mass fraction of 1 to 10%, particularly preferably 2 to 5%.

[0149] In the case of reactively curable adhesives having both at least one photoinitiator for initiating cationic polymerization and at least one photoredox system for initiating free radical polymerization, the above embodiments apply analogously, wherein the skilled person appropriately selects the resulting combined mass fractions of these components and the types and amounts of polymers and reactive resins and additives.

[0150] Pressure-sensitive adhesive

[0151] Preferably, the adhesive at least in the middle region is pressure-sensitive adhesive, and in particular and preferably before the start of chemical conversion, ie at a level of 0% chemical conversion. Therefore, the adhesive in the middle region is preferably a pressure-sensitive adhesive.

[0152] Preferably, due to the partial chemical conversion of the reactive components, the adhesive in the correspondingly treated edge region is not (any longer) pressure-sensitively adhesive.

[0153] According to the understanding of technicians, pressure-sensitive adhesive is understood to refer to the adhesive with pressure-sensitive adhesive properties, that is, even under relatively weak applied pressure, also can form the ability of permanent connection with adhesion substrate.Corresponding pressure-sensitive adhesive tape typically can be separated (peeled off) again from adhesion substrate substantially without residue after use, and generally, even at room temperature, also have permanent inherent viscosity, which means that they have certain viscosity and touch viscosity (contact viscosity), so that even under low applied pressure, also can wet the surface of substrate.The pressure-sensitive adhesive of pressure-sensitive adhesive tape is the result of using pressure-sensitive adhesive as adhesive.Do not wish to be bound by this theory, often assume that pressure-sensitive adhesive can be regarded as the fluid with the extremely high viscosity of elastic component (component), it correspondingly has the characteristic viscoelastic property that causes above-mentioned permanent inherent viscosity and pressure-sensitive adhesive ability.Suppose that in the case of corresponding pressure-sensitive adhesive, when mechanical deformation, there is viscous flow process, and there is the formation of elastic restoring force. Proportional (in a certain proportion) viscous flow is used to achieve adhesion, while proportional (in a certain proportion) elastic restoring forces are 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", 3rd edition (1999), pages 153 to 203. To characterize the degree of elastic and viscous components, the storage modulus (G') and the loss modulus (G") are usually used, which can be determined by dynamic mechanical analysis (DMA), for example using a rheometer as disclosed, for example, in WO2015 / 189233. Within the scope of the present invention, when the pressure is adjusted to 10°C at a temperature of 23°C, the pressure is adjusted to 10°C. 0 to 10 1 rad / s, G′ and G″ are each at least partially within the range of 10 3 to 10 7 Pa, the adhesive is preferably understood to be pressure-sensitively adhesive and is therefore a pressure-sensitive adhesive.

[0154] With regard to the most favorable handling properties, particularly advantageous results are often achieved when the reactively curable adhesive is used as the adhesive layer of a single-sided or double-sided adhesive tape, when the single-sided or double-sided adhesive tape also comprises a carrier layer or the adhesive layer is arranged on a release layer, such as a liner, from which the adhesive layer can be easily released.

[0155] The adhesive tape according to the invention can therefore be a so-called transfer tape, which consists of the reactively curable adhesive layer described.

[0156] However, preference is given to adhesive tapes according to the invention which additionally have at least one carrier layer.

[0157] The carrier layer generally refers to a layer of such a multilayer adhesive tape that crucially determines the mechanical and physical properties of the adhesive tape, such as tensile strength, stretchability, insulating capacity, or resilience (elasticity, elasticity). Conventional materials for the carrier layer are, for example, woven fabrics, laying scrims, and plastic foils, such as PET and polyolefin foils. However, the carrier layer itself can also be pressure-sensitively adhesive.

[0158] In a preferred embodiment, the adhesive tape according to the invention can be a double-sided adhesive tape, the carrier layer of which is provided on both sides with the reactively curable adhesive as described above.

[0159] In this case, each layer of the reactively curable adhesive preferably has corresponding edge regions, so that further adhesive does not escape from the adhesive tape, in particular the adhesive tape roll.

[0160] Preferably, the carrier layer comprises a foil.

[0161] The carrier layer may also have electrically insulating properties, so that the corresponding adhesive tape according to the invention is electrically insulating and can be used for the electrical insulation of articles. For this purpose, a tape having a dielectric strength of >10 % as determined in accordance with DIN EN 62631-3-1 (VDE 0307-3-1): 2017-01 can be used. 15 Ωcm, preferably >10 16 Ωcm, more preferably>10 17 Insulating carrier foil with a specific volume resistivity of Ωcm.

[0162] In a preferred embodiment, the adhesive tape according to the invention can therefore be a double-sided adhesive tape, the insulating carrier foil of which is provided with a reactively curable adhesive on both sides.

[0163] Preferably, the adhesive tape according to the invention is a single-sided adhesive tape.

[0164] The adhesive tape according to the invention is further preferably a single-sided adhesive tape, the electrically insulating carrier foil of which is provided on one side with a reactively curable adhesive. Such single-sided adhesive tapes are very suitable for encapsulating (packaging) battery cells in hybrid and all-electric vehicles.

[0165] Preferably, the carrier foil, which is preferably also insulating, comprises one or more materials selected from the group consisting of polyimide, polybenzimidazole, polyamide, polyetherimide, polyacetal, polyphenylene sulfide, polyetheretherketone, 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, further preferably selected from the group consisting of polypropylene, polyethylene terephthalate, polycarbonate and polyvinyl chloride, further preferably selected from the group consisting of polypropylene and polyethylene terephthalate (PET), wherein the foil particularly preferably comprises PET.

[0166] The thickness of the support is not particularly limited in principle, but is preferably in the range of 20 μm to 100 μm, more preferably in the range of 30 μm to 90 μm, and even more preferably in the range of 40 μm to 75 μm.

[0167] A further subject matter of the present invention is a method for producing an adhesive tape with passivated side edges, in particular an adhesive tape roll with passivated side edges, comprising at least the following method steps:

[0168] i.) providing an adhesive, in particular a reactively curable adhesive, comprising a reactive component, wherein curing occurs by chemical conversion of the reactive component;

[0169] ii.) optionally providing a carrier layer;

[0170] iii.) applying the adhesive to the carrier layer of step ii.) or to a removable layer such as a liner, thereby providing an adhesive tape comprising at least one adhesive layer;

[0171] iv.) optionally rolling the tape into a roll;

[0172] v.) optionally cutting the tape or tape roll;

[0173] vi.) treating the outer edge of the adhesive tape or adhesive tape roll to initiate a chemical conversion of reactive components of the adhesive, so that the chemical conversion of the reactive components of the adhesive in the edge region takes place to an extent of at least 30% in each case and to a higher extent than in the middle region, and wherein the chemical conversion preferably takes place to an extent of 0 to 10%, particularly preferably 0 to 5%, and in particular 0% in the middle region, wherein the treatment is preferably carried out by irradiating the outer edge, in particular by irradiating the outer edge with visible light or UV light.

[0174] With regard to the reactively curable adhesive, the carrier layer and the irradiation, all of the above-described embodiments apply.

[0175] In particular, and preferably, the outer edges are treated so that the chemical conversion of the reactive components of the adhesive takes place in the edge regions to a certain extent in each case, so that no adhesive can escape laterally from the adhesive tape. The treatment increases the viscosity of the adhesive in the edge regions compared to the central region.

[0176] In particular, it is preferred here that a photoinitiator for initiating cationic polymerization is included as the photoactivatable substance and that the reactive resin comprises at least one epoxide compound.

[0177] The invention also relates to the use of the adhesive tape according to the invention for bonding two or more components by curing a curable adhesive.

[0178] A further subject matter of the present invention is the use of the adhesive tape according to the invention for bonding components, in particular batteries or accumulators, in electronic, optical or precision mechanical devices, in automobiles, medical devices and dental devices.

[0179] With regard to effective curing, preference is given to the use according to the invention in which the curing agent is heated to 4000 mJ / cm 2 or greater, preferably 5000 mJ / cm 2 or greater, particularly preferably 6000 mJ / cm 2 or greater minimum dosage for curing of curable adhesives.

[0180] Preferably, according to all subjects of the present invention, the curing of the curable adhesive is carried out with a UV LED, preferably with a UV LED whose maximum emission wavelength is 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, in particular at 365 nm.

[0181] As mentioned above, from the perspective of application technology, it is particularly preferred that the curing is carried out by means of a typical UV LED, which is feasible for curable adhesives, although the effectiveness of the sensitizer is reduced in this case and is also feasible even in the case of high contents of epoxy-modified nitrile rubbers. It is particularly preferred that the cationic photoinitiator is matched to the emission characteristics of the UV LED, in particular the mass ratio between the cationic photoinitiator and the epoxy-modified nitrile rubber defined above is adjusted. DETAILED DESCRIPTION

[0182] Hereinafter, some examples are described to further illustrate the present invention.

[0183] Test Method

[0184] Unless otherwise specified, all measurements were carried out at 23°C and 50% relative humidity. The mechanical and adhesive data obtained are as follows:

[0185] Molar mass Mn, Mw

[0186] The information on the number-average molar mass Mn or weight-average molar mass Mw in this specification relates to determinations by gel permeation chromatography (GPC). The determination was performed on 100 μl of clarified filtered sample (sample concentration 4 g / l). The eluent used was tetrahydrofuran with 0.1% by volume of trifluoroacetic acid. The measurement was performed at 25°C. The precolumn used was a PSSSDV type column, 5 μm, 8.0mm*50mm (the statements here and below are in the following order: type, particle size, porosity, inner diameter*length; ). The following combination was used for separation: PSSSDV column, 5 μm, as well as and Each column was 8.0 mm x 300 mm (columns from Polymer Standards Service; detection was performed with the aid of a Shodex RI71 differential refractometer). The flow rate was 1.0 ml / min. Commercially available HPLC columns from PSS Polymer Standards Service GmbH, Mainz or Agilent were used. -Kit Poly(styrene) high calibration was performed against PMMA standards (polymethyl methacrylate calibration) and in other cases against PS standards (polystyrene calibration).

[0187] thickness

[0188] The thickness of the adhesive layer can be determined by measuring the thickness of a portion (segment) of such an adhesive layer applied to the liner, defined by its length and its width, and subtracting the thickness of a portion (segment) of the same dimensions of the liner used (known or independently determinable). The thickness of the adhesive layer can be determined using a commercial thickness gauge (probe instrument) with an accuracy of less than 1 μm. If fluctuations in the thickness are determined, the average value of the measured values ​​at at least three representative locations is reported, i.e., in particular, measurements are not taken at folds, creases, tips, etc.

[0189] The thickness of the adhesive tape (adhesive strip) or carrier can also be determined similarly to the thickness of the adhesive layer using a commercial thickness gauge (probe instrument) with an accuracy of less than 1 μm. If thickness fluctuations are detected, the average value of the measured values ​​at at least three representative locations is reported, i.e., in particular, measurements are not made at wrinkles, folds, points, etc.

[0190] The following examples according to the invention (labeled "E") and comparative examples (labeled "V") for adhesive tapes or adhesive tape rolls were prepared.

[0191] By mixing the components in a customary manner (numbers are expressed in parts by weight), a reactively curable pressure-sensitive adhesive (pilot plant; coating from a 60% strength butanone solution) was obtained from the components summarized below:

[0192] 34.4% 700 (ethylene-vinyl acetate copolymer, vinyl acetate content 70% by weight, Arlanxeo)

[0193] 17.1% DER331 (liquid bisphenol-A diglycidyl ether, weight-average molar mass Mw <2000 g / mol, Olin)

[0194] 17.1% DER662E (solid bisphenol-A diglycidyl ether, weight-average molar mass Mw <2000 g / mol, Olin)

[0195] 17.1% Polydis 3610 (epoxy-modified nitrile rubber, Schill+Seilacher "Struktol" GmbH)

[0196] 12.8% Capa 3050 (polyester polyol based on polycaprolactone, Ingevity) and

[0197] 1.5% triarylsulfonium hexafluorophosphate CAS: 109037-77-6 (50% concentration in propylene carbonate, weighing data refers to the solution, Sigma-Aldrich).

[0198] For each example prepared from a 60% strength butanone solution, the resulting pressure-sensitive adhesive was applied in each case in a layer thickness of 50 μm onto a siliconized PET liner. After a drying section (10 m, 120° C.), a 50 μm thick blue PET foil was laminated (bonded), and the composite (total layer thickness 100 μm) was rolled into a tape roll with a width (y-direction) of 125 cm.

[0199] On a cutting machine, four rolls each 30 cm wide in the y direction were cut from the mother roll, and the length of each roll was 50 m.

[0200] Side edge passivation was performed on the same day.

[0201] Side edge passivation

[0202] For side edge passivation, the exemplary reactive tape roll is illuminated on each side, i.e., on each of the two outer edges in the y direction, by a light source. The light source is selected to match the activation wavelength of the reactive tape. For the exemplary reactive adhesive described above, The company's 365 nm LED light source was suitable and was used accordingly. The dose in the UV-A range (320 nm–390 nm) was determined using a UV Power Puck II from UVECO (EIT).

[0203] 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 region.

[0204] The data in Table 2 relate to one of the irradiated sides, but identical irradiation was performed on both sides.

[0205] Furthermore, no irradiation was performed in Comparative Example V1.

[0206] The width of the activated area (the width of each edge area) was then optically measured using a VK-X3000 3D laser scanning microscope and a CF ICEPIPlan 5x lens (magnification 84-960) from Keyence Corporation. The sample was scanned at the corners using a microscope and the image was evaluated using a VK-X3000 multi-file analyzer program. This program allows distance measurements to be taken at selected points on the scanned sample surface. The at least partially cured area of ​​the adhesive layer that was activated by irradiation was visibly separated from the uncured area due to turbidity because the adhesive became optically visible (white) by activation.

[0207] The degree of chemical conversion (conversion) was determined by ATR-FTIR (Attenuated Total Reflectance (ATR); Fourier Transform Infrared Spectroscopy (FTIR)).

[0208] For this purpose, the relevant area was placed on an ATR crystal and the irradiation at ∼925 cm was evaluated in comparison with the unirradiated (0% conversion) and fully cured samples (100% conversion). -1 Epoxide signal in the range of .

[0209] Since the relevant region is significantly narrower than the measurement range of ATR-FTIR, several optically altered edge regions 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. 2 The samples were irradiated with UV LEDs and then cured at 23°C / 50% rF (relative humidity) for 3 days to produce fully cured reference samples.

[0210] Adhesive overflow ("oozing")

[0211] With regard to adhesive overflow ("oozing"), the samples were also evaluated after 28 days of storage at 23° C. and 50% rF, and the following categories listed in Table 1 were defined for this purpose:

[0212] Table 1:

[0213] category definition Number of drops 0 No adhesive spillage 0 1 Adhesive overflow in the form of droplets ≤10 2 Adhesive overflow in the form of droplets 11≤50 3 Adhesive overflow in the form of droplets >50 4 Surface (sheet) adhesive overflow Uncountable

[0214] Table 1 shows that the increase in adhesive spillage is associated with an increase in category.

[0215] Table 2:

[0216]

[0217] The examples show that even a passivation of ~200 μm can significantly reduce adhesive bleed (V3). V1 and V2 exhibit very strong adhesive bleed. If the activated edge area is larger than 200 μm (E1 to E3), adhesive bleed is no longer observed. Using ATR-FTIR, epoxy resin conversions exceeding 50% can be measured in the activated area.

[0218] Since side edge passivation logically results in narrow edges with reduced adhesion, an individual maximum width of the activated area must be determined for each application.

[0219] In the reference experiment, a very wide activation area of ​​832 μm was produced at a longer irradiation time.

[0220] Compared to E2, when the edge of a rectangular aluminum block was taped with a 1 mm strip at the edge, it was found that the activated area was already too large and the restoring forces were stronger than the remaining adhesive forces, causing the applied activated tape edge or the 1 mm wide strip to detach from the aluminum block. This was not observed for E1 to E3, nor for V1 to V3.

[0221] The (overlap) bond strength of the transfer tape according to the invention is completely unaffected in the central region independently of the side edge passivation and is greater than 7 MPa. BRIEF DESCRIPTION OF THE DRAWINGS

[0222] Hereinafter, preferred embodiments of the present invention will be further explained and described with reference to the accompanying drawings. In this, there is shown:

[0223] Figure 1 : A cross section of the adhesive tape according to the present invention viewed from above in the z direction.

[0224] Figure 1 A schematic diagram shows an exemplary adhesive tape 1 according to the invention.

[0225] The adhesive tape has a width 2, which corresponds to the extension of the adhesive tape in the y-direction. The extension of the adhesive tape in the x-direction corresponds to the direction in which the adhesive tape can be rolled up into a roll.

[0226] The adhesive tape has a first outer edge 3 and a second outer edge 4 in the y-direction.

[0227] The adhesive tape is shown in a top view from the z direction. In the x, y plane there is a layer of reactively curable adhesive. This is, for example, the adhesive used above for Examples E1 to E3 according to the invention.

[0228] The adhesive tape is treated as described above at the outer edges 3 and 4 , in particular and for example by UV irradiation, also as described above by way of example.

[0229] As a result, the reactively curable adhesive of the treated tape is activated at the outer edges 3 and 4, respectively, so that the adhesive over the width 2 has different areas, namely the corresponding edge areas 3a and 4a (in which the reactively curable adhesive is cured to an extent of at least 30%), and the middle area 5 (which has not been exposed to radiation and in which a chemical conversion of the reactive components has occurred to 0%).

[0230] The edge regions 3 a and 4 a each have a width 3 b or 4 b in the y-direction of more than 200 μm.

[0231] Figure 1 The illustration in FIG is purely schematic, wherein the width ratios, for example 3b to 2, may differ from the ratios preferred according to the invention.

[0232] List of reference numerals:

[0233] 1 Adhesive tape according to the present invention

[0234] 2 The width of the tape in the y direction

[0235] 3 First outer edge

[0236] 3a First edge region, where the adhesive is activated

[0237] 3b The width of the first edge region in the y direction

[0238] 4 Second outer edge

[0239] 4a Second edge region, where the adhesive is activated

[0240] 4b The width of the second edge region in the y direction

[0241] 5 Middle area

Claims

1. A reactively curable adhesive tape (1) 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 occurs 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 an intermediate region (5) arranged between the edge regions, wherein the reactive components of the adhesive are chemically converted in the edge regions (3a, 4a) to an extent of at least 30% in each case and to a higher extent than in the intermediate region (5), and wherein the chemical conversion preferably takes place in the intermediate region (5) to an extent of 0 to 10%, particularly preferably 0 to 5%, and in particular 0%, wherein each edge region (3a, 4a) has a width in the y direction of greater than 200 μm.

2. The adhesive tape according to claim 1, wherein The reactively curable adhesive comprises at least one photoactivatable substance which initiates a chemical conversion of the reactive components by activation with UV light or visible light, and wherein the chemical conversion of the reactive components of the adhesive in the edge region (3a, 4a) is carried out by irradiating the outer edge (3, 4) with UV light or visible light of the wavelength required for activation of the photoactivatable substance.

3. The adhesive tape according to claim 2, wherein: The reactively curable adhesive comprises at least one photoinitiator for initiating cationic polymerization or at least one photoredox system for initiating free radical polymerization, and the wavelength of visible light or UV light is selected so that it corresponds to the activation wavelength of the photoinitiator or the photoredox system, wherein at least one photoinitiator for initiating cationic polymerization is preferred.

4. The adhesive tape according to claim 3, wherein The reactive curable adhesive comprises at least the following components: a) at least one polymer; and b) at least one reactive resin; and c) at least one photoinitiator for initiating cationic polymerization or at least one photoredox system for initiating free-radical polymerization, wherein at least one photoinitiator for initiating cationic polymerization is preferred.

5. Adhesive tape according to any one of the preceding claims, characterized in that At least the adhesive is pressure-sensitively adhesive in said middle region (5).

6. Adhesive tape according to any one of the preceding claims, 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.

7. The 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 250 μm to 750 μm, in particular 300 μm to 600 μm.

8. Adhesive tape according to any one of the preceding claims, characterized in that It further comprises at least one carrier layer.

9. The adhesive tape according to claim 8, characterized in that The carrier layer comprises a film, wherein the film preferably comprises polyethylene terephthalate (PET).

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

11. Adhesive tape according to any one of the preceding claims, characterized in that It is in the form of a roll of adhesive tape, wherein the y-direction corresponds to the axial direction of the roll of adhesive tape.

12. A method for producing an adhesive tape with passivated side edges, in particular an adhesive tape roll with passivated side edges, comprising at least the following method steps: i.) providing an adhesive, in particular a reactively curable adhesive; ii.) optionally providing a carrier layer; iii.) applying the adhesive to the carrier layer of step ii.) or to a removable layer such as a liner, thereby providing an adhesive tape comprising at least one adhesive layer; iv.) optionally rolling the tape into a roll; v.) optionally cutting the tape or tape roll; vi.) treating the outer edge of the adhesive tape or adhesive tape roll to initiate a chemical conversion of reactive components of the adhesive, so that the chemical conversion of the reactive components of the adhesive in the edge region takes place to an extent of at least 30% in each case and to a higher extent than in the middle region, and wherein the chemical conversion preferably takes place to an extent of 0 to 10%, particularly preferably 0 to 5%, and in particular 0% in the middle region, wherein the treatment is preferably carried out by irradiating the outer edge, in particular by irradiating the outer edge with visible light or UV light.

13. Use of the adhesive tape according to any one of claims 1 to 11 for bonding components, in particular batteries or accumulators, in electronic, optical or precision mechanical devices, automobiles, medical devices and dental devices.

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