Pressure sensitive adhesive and reseparatable self-adhesive product comprising the

Abstract

The present invention relates to a pressure sensitive adhesive comprising: a) from 28% to 60% by weight of an elastomeric component wherein i. The elastomeric component comprises at least 60% by weight of a hydrogenated polyvinyl aromatic-polydiene block copolymer having a polyvinyl aromatic fraction of at least 18% by weight and a peak molecular weight of from 100,000 to 500,000 g / mol (test I), ii. The polydiene block is substantially fully hydrogenated, iii. The hydrogenated polyvinyl aromatic-polydiene block copolymer has an ABA structure, an (AB) nZ structure wherein n = 2 or a radial (AB) n structure or a radial (AB) n-Z structure wherein n > = 3, and iv. The elastomer component comprises a hydrogenated diblock copolymer having an A 'B' structure or an (A 'B') nZ structure where n = 1, b) a tackifier resin component, c) optionally a plasticizer component, d) at least 2.5 to 22% by weight of a reinforcing component which is a resin having an MMAP value of between-10 DEG C and + 30 DEG C and a softening point of at least 140 DEG C, e) optionally further auxiliaries.

Description

Technical Field

[0001] The present invention relates to a pressure-sensitive adhesive and a self-adhesive product, and more particularly, to a double-sidedly-adhesive self-adhesive product which is redetachable from an adhesive bond by extensive stretching and includes the pressure-sensitive adhesive. Background Art

[0002] Adhesives and adhesive tapes are often used to assemble two substrates in order to form a durable or permanent bond. Last but not least, there is a clear trend that such permanent bonds should be separated again for recycling purposes. Therefore, adhesive technology solutions are sought that initially offer application-oriented bonding properties, but which can also be separated again. One of the challenges here is to achieve bonding properties that correspond to increasingly demanding applications, for example with regard to the materials to be bonded, but also with regard to the resistance of the bond. For example, automotive bonding, including bonding to mounted plastic parts, requires high hot shear strength. Common materials for such mounted parts are PP / EPDM, PP / EPM or PP / EPR. Bonding such materials is a particular challenge.

[0003] Self-adhesive products are known which are separable again by stretching and which comprise one or more layers based on styrene block copolymers.

[0004] From DE 100 03 318 A1, DE 102 52 088 A1, DE 10 52 089 A1 and DE 10 2007 021 504 A1 it is known to propose formulations based on hydrogenated polystyrene-polydiene block copolymers which are suitable for self-adhesive products which can be separated again by stretching.

[0005] Furthermore, it is known to use so-called end-block reinforcers in formulations with hydrogenated polystyrene-polydiene block copolymers.

[0006] EP 0 302 394 A2 teaches formulations comprising SEBS triblocks and / or diblocks (preferably 20-40%) with hydrogenated aromatic resins and optionally endblock reinforcing agents ("non-hydrogenated pure monomer endblock reinforcing resins"). The disclosed compositions which do contain endblock reinforcing agents have an elastomer fraction of only about 25%.

[0007] EP 1 700 895 A1 discloses formulations comprising SEPS and / or SEEPS and a tackifier resin and optionally additionally an aromatic resin, having an elastomer content of 1 to 10% by weight.

[0008] EP 3 650 500 A1 and EP 3 798 262 A1 describe formulations with hydrogenated SBCs and a maximum elastomer content of about 12% by weight.

[0009] However, there is still a need to develop robust adhesives and corresponding products comprising these adhesives, which have an excellent property profile that meets the corresponding requirements even after storage under hot and humid conditions. Summary of the invention

[0010] Therefore, the object of the present invention is to provide a pressure-sensitive adhesive and a self-adhesive product comprising the pressure-sensitive adhesive which can be separated again by stretching, characterized by improved separation characteristics after heat and humidity storage of the corresponding adhesive assembly comprising the pressure-sensitive adhesive or the self-adhesive product. At the same time, a high degree of long-term stability is to be ensured. In addition, the pressure-sensitive adhesive or the self-adhesive product should have good adhesion properties, especially to polar substrates such as steel, and also possibly to non-polar substrates such as PP / EPDM, PP / EPM or PP / EPR, despite its re-separability. In addition, the pressure-sensitive adhesive or the self-adhesive product should have an optimal hot shear strength.

[0011] This object is achieved in an unexpected manner by the pressure-sensitive adhesive and self-adhesive product described herein. The subordinate subject matter is an advantageous development of the subject matter of the present invention. In addition, the adhesive-bonded components are part of the present invention. Other advantageous configurations of the present invention come from the following description.

[0012] In a more preferred embodiment, such and further embodiments designated below as preferred are combined with features of other embodiments designated as preferred. Therefore, particularly preferred are combinations of two or more embodiments described below as more preferred. Also preferred are embodiments in which features of one embodiment designated as preferred to any extent are combined with one or more other features of other embodiments designated as preferred to any extent.

[0013] Characteristics of preferred self-adhesive products and uses derive from characteristics of preferred pressure-sensitive adhesives. DETAILED DESCRIPTION

[0014] A first subject of the present invention is a pressure-sensitive adhesive comprising:

[0015] a) at least 28 wt. % and at most 60 wt. % of an elastomeric component, wherein

[0016] i. the elastomeric component comprises at least 60% by weight and preferably up to 90% by weight of at least one hydrogenated polyvinylaromatic-polydiene block copolymer having a polyvinylaromatic fraction of at least 18% by weight and a peak molecular weight determined by GPC of from 100 000 to 500 000 g / mol (Test I), based in each case on the elastomeric component,

[0017] ii. the polydiene blocks are substantially fully hydrogenated,

[0018] iii. The hydrogenated polyvinyl aromatic compound-polydiene block copolymer has an ABA structure, wherein n=2 (AB) n Z structure or radial (AB) where n≥3 n Structure or radial (AB) n -Z structure, wherein A=polyvinyl aromatic compound, B=ethylene and butene or ethylene and propylene, and Z=derivative of coupled substance, and wherein the ethylene fraction in the B block is preferably at least 50% by weight, and

[0019] iv. The elastomer component comprises at least one (A'B') having an A'B' structure or wherein n=1 n A hydrogenated diblock copolymer of structure Z, wherein A'=polyvinyl aromatic compound, B'=ethylene and butene or ethylene and propylene, Z=derivative of coupled substance, and possibly A'=A and B'=B,

[0020] b) a tackifier resin component,

[0021] c) optionally a plasticizer component,

[0022] d) at least 2.5% to 22% by weight, preferably at least 4% to 18% by weight, of a reinforcing component of at least one resin having an MMAP value between -10°C and +30°C, preferably between 0°C and +20°C, and a softening point of at least 140°C,

[0023] e) optionally further auxiliaries,

[0024] The fraction of the elastomeric component is based on the total weight of the pressure sensitive adhesive.

[0025] In the context of the present invention, "substantially fully hydrogenated" means a degree of hydrogenation of at least 90%, preferably at least 95% and particularly preferably at least 99%. Hydrogenated block copolymers are understood within the scope of the present invention to mean those in which the polydiene blocks are substantially fully hydrogenated.

[0026] Examples of coupling substances which can be used according to the invention can be found in publications including Holden (G. Holden, DR Hansen in "Thermoplastic Elastomers", G. Holden, HR Kricheldorf, RP Quirk (Eds.), 3rd edition 2004, C. Hanser, Munich, p. 49f), without wishing to impose any restrictions thereby.

[0027] According to the general understanding, pressure-sensitive adhesives are understood to mean adhesives which allow permanent connection to almost all adhesive substrates even at relatively low contact pressures and, if necessary, can be separated from the adhesive substrate again after use in a substantially residue-free manner. Pressure-sensitive adhesives have permanent pressure-sensitive adhesion at room temperature, i.e. have sufficiently low viscosity and high touch tack to wet the surface of the corresponding substrate even at low contact pressures. The adhesive's bondability is based on its adhesive properties, and its re-separability is based on its cohesive properties.

[0028] In the context of the present invention, the term "hot and humid conditions" refers in particular to conditions comprising a relative humidity of more than 60% and an ambient temperature of more than 25°C.

[0029] In the context of the present invention, the test used a temperature of 85° C. and a relative humidity of 85% as the standardized ambient climate.

[0030] "Storage under heat and humidity conditions" means in particular that the material or article under consideration is stored for a period of time greater than one day at a relative humidity of more than 60% and an ambient temperature of more than 25° C. In this case, long storage times, such as in particular more than 100 hours, for example 500 or 1000 hours, are particularly important.

[0031] Pressure sensitive adhesive

[0032] The pressure-sensitive adhesive of the present invention preferably meets the performance requirements specified in the following table.

[0033] Table 1 - Preferred performance profile

[0034]

[0035] "Tear rate 85°C" or "Tear rate 85C / 85% rel.h." (rel.h. = relative humidity) means the tear rate after storage of the sample for 7 days under the specified conditions, ie at elevated temperature or heat / humidity conditions (see test methods).

[0036] In the context of the present invention, it is finally important that an advantageous combination of properties, in particular high peel adhesion and optimized release characteristics, even after storage under hot and humid conditions, can also be achieved by a balanced coordination of the individual components of the pressure-sensitive adhesive, but cannot be achieved by those disclosed in many cases in the prior art.

[0037] a) Elastomer component

[0038] Suitable formulations according to the invention are therefore formulations which comprise at least 28% by weight and at most 60% by weight, preferably between 35% and 58% by weight, very preferably between 40% and 52% by weight, of an elastomeric component, wherein the elastomeric component comprises at least 60% by weight, preferably at least 70% by weight and very preferably at least 80% by weight, and preferably at most 90% by weight, based on the elastomeric component, of at least one hydrogenated polyvinylaromatic-polydiene block copolymer.

[0039] The at least one hydrogenated polyvinylaromatic-polydiene block copolymer used according to the invention is characterized by a linear ABA structure or a linear (AB) structure in which n=2. n Z structure or radial (AB) where n≥3 n Structure or radial (AB) n Z structure.

[0040] The vinyl aromatic compound used to form the A block preferably includes styrene, alpha-methylstyrene and / or other styrene derivatives. Therefore, the A block can be in the form of a homopolymer or a copolymer. More preferably, the A block is polystyrene. This type of block copolymer forms the backbone of the formulation. They form an important part, through which the adhesive properties and tear resistance are affected, and therefore the separation characteristics are affected. However, the molar mass fraction of this type of block copolymer is too high or improperly selected, which can reduce the peel adhesion. In order to optimally balance these properties, it has been found that this type of block copolymer should have a peak molecular weight of at least about 100,000 g / mol and at most about 500,000 g / mol. The higher the molecular weight, the more challenging the processability of the material. Therefore, a peak molecular weight of no more than 250,000 g / mol is preferred. Very advantageous are linear triblock copolymers or radial block copolymers having a peak molecular weight between 100 000 and 200 000 g / mol, in particular between 100 000 and 180 000 g / mol.

[0041] In order to achieve a satisfactory performance profile, a polyvinyl aromatic fraction of at least 18 wt. % is selected in the at least one block copolymer of this type. However, this fraction should not be too high, since if the fraction is too high, the peel adhesion will decrease. Advantageously, the polyvinyl aromatic fraction is not higher than 35 wt. %. A polyvinyl aromatic fraction in the range between 20 wt. % and 33 wt. % is advantageous. The polyvinyl aromatic fraction in the hydrogenated polyvinyl aromatic-polydiene block copolymer can be increased, for example, by 1 H or 13 C-NMR (nuclear magnetic resonance spectroscopy, test IX) determination. For commercially available hydrogenated polyvinylaromatic-polydiene block copolymers, the polyvinylaromatic fraction can also be found in the manufacturer's specifications.

[0042] The hydrogenated polyvinyl aromatic compound-polydiene block copolymers used in the pressure-sensitive adhesive of the present invention are preferably those obtained by anionic polymerization and subsequent addition of the monomers of the corresponding polymer blocks, the vinyl aromatic compound of the A block and the diene of the B block. In many manufacturing processes, the diblock intermediate AB is coupled to a triblock copolymer (2AB+Z'→AB-Z-BA) or a radial copolymer using a coupling agent Z'. Subsequently, the B block is selectively hydrogenated so that preferably ethylene and butene or ethylene and propylene form the B block.

[0043] Preferably, block copolymers are used which are substantially fully hydrogenated with respect to the polydiene blocks (B blocks). The ethylene fraction in the B blocks is preferably at least 50% by weight.

[0044] According to a preferred embodiment of the present invention, the elastomeric component contained in the pressure-sensitive adhesive is non-sulfonated in the vinyl aromatic block.

[0045] In order to further improve the property profile of the pressure-sensitive adhesive according to the invention, it has proven to be advantageous if the elastomeric component comprises up to 35% by weight, based on the elastomeric component, of the at least one hydrogenated diblock copolymer.

[0046] The polymer blocks defined and comprised according to iii. and iv. may differ, for example, in molar mass and / or composition.

[0047] Preferably, the fraction of hydrogenated diblock copolymer in the elastomeric component does not exceed 35% by weight, preferably from 10% to 30% by weight, based in each case on the total weight of the elastomeric component.

[0048] Hydrogenated diblock copolymers can be used advantageously to influence peel adhesion and flow-on characteristics.

[0049] In a preferred embodiment, the at least one diblock copolymer has a peak molecular weight determined by GPC of <100,000 g / mol.

[0050] In a further preferred embodiment, the at least one diblock copolymer has a peak molecular weight determined by GPC of greater than 100 000 g / mol.

[0051] According to a preferred embodiment, the elastomeric component further comprises a further hydrogenated polyvinyl aromatic compound-polydiene block copolymer characterized by a linear ABA structure and a linear (AB) structure wherein n=2 n Z structure or radial (AB) where n≥3 n The block copolymer may have a polyvinyl aromatic fraction of less than 18% by weight or more and independently have a peak molecular weight greater than 500 000 g / mol or less than 100 000 g / mol or between the two. It may also contain several of this type.

[0052] As a result, the pressure-sensitive adhesive exhibits improved processability.

[0053] b) Tackifier resin component

[0054] The pressure-sensitive adhesive of the present invention further comprises a tackifier resin component.

[0055] The tackifier resin component is in particular one or more tackifier resins.

[0056] In the context of the present invention, the tackifier resin component should not be understood as a reinforcing component, ie, the tackifier resin component is preferably substantially incompatible with the hard blocks of the polydiene block copolymer.

[0057] Thus, the tackifier resin or resins are selected to be miscible (compatible) primarily with the predominantly B block regions of the pressure sensitive adhesive.

[0058] The tackifier resin component is used in particular to set the adhesion in a desired manner. According to the general understanding of the person skilled in the art, "tackifier resin" is understood to mean an oligomeric or polymeric resin which increases the adhesion (i.e., the intrinsic tack) of a pressure-sensitive adhesive compared to an otherwise identical pressure-sensitive adhesive without any tackifier resin. Tackifier resins are specific compounds with a lower molar mass than elastomers, typically having a weight-average molecular weight M of less than 5000 g / mol. w Typically, the tackifier resin component used in the context of the present invention has a weight average molecular weight of from 400 to 5000 g / mol, preferably from 500 to 2000 g / mol, determined by GPC (Test 1b).

[0059] The fraction of the tackifier resin component in the pressure-sensitive adhesive has a positive influence on the bond strength. Therefore, the tackifier resin fraction should not be too low. However, it has been shown that too high a fraction of the tackifier resin has a negative effect on the hot shear strength and, in particular, on the re-detachability.

[0060] The fraction of the tackifier resin component is preferably 28% to 55% by weight, more preferably 35% to 50% by weight, based on the total weight of the pressure-sensitive adhesive.

[0061] At least one tackifier resin is further characterized by a softening temperature by the Ring and Ball method greater than 95°C, but not more than 135°C. The softening temperature can be determined according to Test IV as described below. Preferably, all tackifier resins in the tackifier resin component have a softening temperature within this range.

[0062] Preferably, the at least one tackifier resin of the tackifier resin component is selected from dicyclopentadiene-based resins, C-based 5 , C 5 / C 9 or C 9 Hydrocarbon resins of monomer streams, polyterpene resins based on α-pinene and / or β-pinene and δ-limonene, and pure C 8 or C 9 Polymers of aromatic compounds, the resins being partially or especially fully hydrogenated.

[0063] In the context of the present invention, "partially hydrogenated" means a degree of hydrogenation of at least 80%, preferably at least 85%.

[0064] The adhesive of the invention preferably has in the tackifier resin component at least one tackifier resin having a DACP (diacetone alcohol cloud point) of at least 30° C., preferably at least 40° C. The DACP is determined according to Test V as described below.

[0065] In another preferred embodiment, the pressure-sensitive adhesive of the invention comprises in the tackifier resin component at least one tackifier resin having a MMAP (mixed methylcyclohexane aniline point) greater than 60° C., preferably greater than 70° C. The MMAP is determined according to Test VI as described below.

[0066] In addition to the at least one tackifier resin described above, the tackifier resin component may also contain one or more additional tackifier resins that do not meet the prescribed definitions of softening temperature and / or DACP and / or MMAP cloud point. Tackifier resins having a softening temperature below 95° C., such as about 90° C. or about 85° C., may also be used in proportions of up to 10% by weight or even up to 20% by weight, relative to the composition of the tackifier resin component. For example, tackifier resins having a softening temperature above 135° C., such as about 140° C., may also be used in proportions of up to 10% by weight or even up to 20% by weight, relative to the composition of the tackifier resin component.

[0067] Tackifier resins having an MMAP cloud point below 60° C. or even below 45° C. and / or a DACP cloud point below 30° C. or even below 15° C. may also be used in proportions of up to 20% by weight or even up to 40% by weight, relative to the composition of the tackifier resin component. Examples of such tackifier resins are terpene-phenol resins, in particular terpene-phenol resins having an OH value of not more than 100 mg KOH / g, and rosin esters which may be partially hydrogenated, fully hydrogenated or disproportionated.

[0068] c) Plasticizer component

[0069] The pressure-sensitive adhesive of the present invention may further contain a plasticizer component in addition to the elastomer component and the tackifier resin component.

[0070] The fraction of the plasticizer component is preferably 2% to 25% by weight, particularly preferably 2% to 20% by weight, very preferably 4% to 15% by weight, based on the total weight of the pressure-sensitive adhesive. Surprisingly, it has been found that already very low proportions of the stated amount of plasticizer component are sufficient to obtain a pressure-sensitive adhesive with sufficiently high bond strength, contrary to what is taught in the prior art, in which in some cases a plasticizer content of 60% to 95% by weight is assumed.

[0071] The plasticizer component is one or more plasticizers.

[0072] The plasticizer is preferably selected from ethylene / propylene copolymers, ethylene / butene copolymers, butene / isobutene (co)polymers, butene homopolymers and isobutene homopolymers, in each case preferably the amorphous representatives.

[0073] In another preferred embodiment, the plasticizer has a weight average molecular weight of at least 100 000 g / mol and at most 1 000 000 g / mol, determined by GPC (Test I). In these cases, the plasticizer is preferably an ethylene / propylene copolymer or an ethylene / butene copolymer with a linear or radial structure. These copolymers included as plasticizer components are not block copolymers containing hard blocks within the scope of the present invention.

[0074] In a further particularly preferred embodiment, the plasticizer has a weight-average molar mass of at least 3000 g / mol and at most 20 000 g / mol, determined by GPC (test I). In this case, the plasticizer is preferably a butene / isobutene (co)polymer.

[0075] Plasticizer resins based on rosin, in particular methyl esters of rosin or of partially or fully hydrogenated rosin, are also suitable.

[0076] d) Reinforcement components

[0077] The pressure-sensitive adhesive of the present invention comprises a reinforcing component.

[0078] Within the scope of the present invention, the reinforcing component should not be understood to mean the tackifier resin component, ie the reinforcing component is preferably substantially incompatible with the soft block (ie the polydiene block).

[0079] In particular, so-called end-block reinforcing agents are used as reinforcing components according to the invention.

[0080] End block reinforcing agents refer to those materials that are substantially compatible with the hard blocks of the polydiene block copolymer.

[0081] The at least one resin of the reinforcing component is preferably at least one resin based on at least one, in particular aromatic hydrocarbon compound, preferably chosen from styrene, α-methylstyrene, p-methylstyrene and copolymers thereof.

[0082] The at least one resin of the reinforcing component preferably has a weight average molecular weight M of 1000 to 15 000 g / mol, more preferably 2000 to 10 000 g / mol, as determined by GPC. w (Test 1b).

[0083] The at least one resin of the reinforcing component has a mixed methylcyclohexane aniline (MMAP) cloud point (test VI) of -10°C to +30°C, preferably 0°C to +20°C.

[0084] The softening point of the at least one resin of the reinforcing component is at least 140° C., preferably at least 150° C., determined according to Test IV.

[0085] The fraction of the reinforcing component is at least 2.5% by weight and at most 22% by weight, preferably at least 4% by weight and at most 18% by weight, based on the total weight of the pressure-sensitive adhesive.

[0086] In the context of the present invention, the expressions “substantially incompatible” or “substantially incompatible” are understood in particular to mean that the ingredients or components mentioned are miscible with one another to an extent of at most 10% by weight, preferably at most 5% by weight.

[0087] In the context of the present invention, the expression “substantially compatible” is understood in particular to mean that the ingredients or components mentioned are miscible with one another to an extent of at least 90% by weight, preferably at least 95% by weight.

[0088] c) Other additives

[0089] In order to further adjust the performance profile of the pressure-sensitive adhesive of the present invention, additional auxiliary agents can be added to the pressure-sensitive adhesive. These are preferably selected from the following auxiliary agents: primary antioxidants (primary antioxidants) such as sterically hindered phenols, secondary antioxidants (secondary antioxidants) such as phosphites or thioethers, process stabilizers such as C free radical scavengers, light stabilizers such as UV absorbers or sterically hindered amines, processing aids and other elastomers such as those based on pure hydrocarbons, such as unsaturated polydienes, natural or synthetically produced polyisoprene or polybutadiene, chemically basically saturated elastomers such as saturated ethylene-propylene copolymers, α-olefin copolymers, polyisobutylene, butyl rubber, ethylene-propylene rubber and functionalized hydrocarbons, such as halogen-containing, acrylate-containing or vinyl ether-containing polyolefins. In addition, organic or inorganic fillers, as well as dyes and color pigments can be used. The pressure-sensitive adhesive can be black, gray, white or correspondingly colored.

[0090] Self-adhesive products

[0091] As already mentioned, a further subject matter of the present invention is a self-adhesive product which is separable again by stretching and which has at least one layer of the pressure-sensitive adhesive according to the invention.

[0092] The self-adhesive product according to the invention can be designed to be adhesive on one side or on both sides, ie on both sides, wherein the adhesive layer is preferably formed in each case from the pressure-sensitive adhesive of the invention.

[0093] Furthermore, the self-adhesive product according to the invention has at least one ply of temporary carrier material (“release liner”).

[0094] Such temporary carrier materials are in particular film-like materials from which the pressure-sensitive adhesive layer can be detached so that the remainder of the self-adhesive tape can then come into contact with the substrate to be bonded or with another material with which the remainder of the self-adhesive tape will form a bond.

[0095] The temporary carrier material is in particular a release paper or a release film, also called a release liner, which is in any case a material which is not firmly connected to the pressure-sensitive adhesive layer, which material is in particular provided with a release so that the pressure-sensitive adhesive layer can be separated therefrom. It thus facilitates its production, storage or further processing, for example by die cutting.

[0096] Using at least one of the above pressure-sensitive adhesives, according to a preferred embodiment of the present invention, the self-adhesive product according to the present invention is

[0097] a single-layer, double-sided self-adhesive tape which consists of a single layer of the pressure-sensitive adhesive according to the invention and which is thus a transfer tape, or

[0098] - a multilayer double-sided self-adhesive tape, each layer of which consists of the pressure-sensitive adhesive of the invention, or

[0099] a multilayer, double-sided self-adhesive tape having a permanent carrier, the carrier being arranged in a layer of the pressure-sensitive adhesive according to the invention or between two layers of the pressure-sensitive adhesive according to the invention,

[0100] a multilayer, single-sided self-adhesive tape having a layer of the pressure-sensitive adhesive according to the invention and a permanent carrier,

[0101] - in each case in combination with a temporary carrier material.

[0102] According to a preferred embodiment of the invention, the self-adhesive product which can be separated again by stretching has at least one layer of an extensible permanent carrier material.

[0103] A further subject matter of the present invention is therefore a self-adhesive product having a temporary carrier material and a permanent carrier carrying at least one applied layer of the pressure-sensitive adhesive according to the invention.

[0104] The invention also relates to a self-adhesive product having a temporary carrier material and a permanent carrier, carrying on both sides an applied layer of the pressure-sensitive adhesive of the invention, the two layers of which may consist of the same or different adhesives. In addition, the invention relates to a self-adhesive tape having a temporary carrier material and a permanent carrier, carrying on one side an applied layer of the pressure-sensitive adhesive of the invention and on the other side an applied further adhesive not of the invention. The latter may be a pressure-sensitive adhesive or a non-pressure-sensitive adhesive and / or heat-sealable.

[0105] Therefore, a double-sided product can have a symmetrical or asymmetrical product structure.

[0106] Preference is also given to single-layer, double-sided self-adhesive tapes composed of a single layer of the pressure-sensitive adhesive of the invention combined with a temporary carrier material.

[0107] Furthermore, embodiments of the self-adhesive product are preferred in which the permanent carrier consists of only a single layer of polymer film.

[0108] Further preferred are multilayer, single-sided self-adhesive products constructed from at least one layer of the pressure-sensitive adhesive of the invention and a permanent carrier. The pressure-sensitive adhesive of the invention preferably represents the outer oriented adhesive layer of the self-adhesive product, so that it - independently of the temporary carrier material - can be used for bonding to substrates.

[0109] In all embodiments, the permanent carrier is preferably a film, in particular a stretchable film.

[0110] In particular, the concept of the present invention is included in the structure of a ductile permanent carrier in the middle of the self-adhesive product, in particular in the middle of the monolayer of the pressure-sensitive adhesive of the present invention, wherein the ductility of the intermediate carrier must be sufficient to ensure that the adhesive strip is separated by stretching. For example, extremely stretchable films can be used as permanent carriers. Advantageously, examples of ductile permanent carriers that can be used are transparent versions from WO 2011 / 124782A1, DE 10 2012 223 670 A1, WO 2009 / 114683A1, WO 2010 / 077541A1, WO 2010 / 078396 A1.

[0111] However, the permanent support need not be transparent. It may in particular be black, grey, white or coloured.

[0112] To produce the permanent carrier films, film-forming or extrudable polymers are used which may also be uniaxially or biaxially oriented.

[0113] According to a preferred embodiment, the extensible permanent carrier material is a stretchable film.

[0114] According to a preferred embodiment, the film is made of at least one polyolefin. Preferred polyolefins are prepared from ethylene, propylene, butene and / or hexene, wherein in each case pure monomers can be polymerized or mixtures of said monomers can be copolymerized. The physical and mechanical properties of the polymer film, such as softening temperature and / or elongation at break, can be controlled by the polymerization process and by the choice of monomers.

[0115] Polyurethanes can also be used well as starting materials for ductile permanent carrier layers. Polyurethanes are chemically and / or physically crosslinked polycondensates, which are usually formed from polyols and isocyanates. Depending on the properties and the proportions used of the individual components, ductile materials that are advantageously used in the context of the present invention can be obtained. For example, EP 0 894 841 B1 and EP 1 308 492 B1 specify raw materials that can be used by formulators for this purpose.

[0116] The person skilled in the art is aware of other raw materials from which the permanent support layer according to the invention can be constructed. Polyester polyurethanes, polyether polyurethanes and polycaprolactone polyurethanes are mentioned here as examples of polyurethanes which can advantageously be used as base materials for the permanent support in the sense of the invention.

[0117] Furthermore, in order to achieve ductility, it is advantageous to use materials based on ethylene vinyl acetate (EVA) copolymers in the permanent carrier layer.

[0118] Therefore, preferred is a self-adhesive product according to the invention which, as an extensible permanent carrier material, has at least one stretchable film, which is preferably made of at least one material selected from the group consisting of polyolefins such as ethylene, propylene, butene and hexene, polyurethanes, polyester polyurethanes, polyether polyurethanes, polycaprolactone polyurethanes, ethylene-vinyl acetate (EVA) copolymers and rubber-based materials.

[0119] Further preferably, the carrier is a foam carrier, particularly preferably a foam carrier made of PE or PU foam. The foam can have cells of any known form, i.e. can be open or closed. The foaming can be produced by chemical or physical foaming agents, by injecting gases or in particular air ("foaming") or by introducing hollow spheres, these enumerations are not decisive but are to be understood only as examples. Specific examples are hollow glass spheres, hollow ceramic spheres, hollow metal spheres and expanded, expandable and pre-expanded microspheres. Combinations of the various mentioned foaming methods and other foaming methods are also possible.

[0120] For the production of permanent supports, additives and further components may also be added here as appropriate to improve the film-forming properties, to reduce the tendency to form crystalline segments, if present and desired, and / or to selectively improve or impair the mechanical properties.

[0121] The permanent carrier may be of multi-layer design.

[0122] Furthermore, the permanent carrier may have an outer layer, such as a barrier layer, which prevents the penetration of components from the adhesive into the permanent carrier and vice versa. These outer layers may also have barrier properties, in order to thereby prevent the penetration of water vapor and / or oxygen.

[0123] In order to better anchor the pressure-sensitive adhesive on the permanent carrier, the permanent carrier can be pretreated by known measures such as corona, plasma or combustion. Primers can also be used. However, ideally, pretreatment can be omitted.

[0124] The back side of the permanent support may have been subjected to an anti-stick physical treatment or coating.

[0125] The thickness of the permanent carrier layer is generally in the range from 10 to 200 μm, preferably between 20 and 100 μm.

[0126] The strain at 50% elongation ("peel force", Test VII) should be less than 20 N / cm, preferably less than 10 N / cm, in order to allow easy separation without exerting excessive force.

[0127] Particularly advantageous are self-adhesive products consisting of:

[0128] a single-layer permanent support, preferably consisting of polyurethane, wherein the support has an elongation at break of at least 100%, preferably at least 300%, and optionally a resilience of more than 50% (Test VIII), and

[0129] The carrier carries on both sides respectively applied layers of the pressure-sensitive adhesive of the invention, wherein preferably the composition of the adhesive is identical.

[0130] Particularly advantageous are self-adhesive products consisting of:

[0131] a single-layer permanent support, preferably comprising a polyolefin, wherein the support has an elongation at break of at least 100%, preferably at least 300%, and optionally a resilience (Test VIII) of more than 50%, and

[0132] The carrier carries on both sides respectively applied layers of the pressure-sensitive adhesive of the invention, wherein preferably the composition of the adhesive is identical.

[0133] For the purposes of the present invention, the generic terms "self-adhesive products" and "self-adhesive tapes" include all flat structures such as two-dimensionally extending films or film portions, tapes with extended length and limited width, tape portions, etc., and ultimately also cut pieces, die cuts or labels.

[0134] Thus, the self-adhesive product has a longitudinal extent and a transverse extent. The adhesive tape also has a thickness extending perpendicularly to the two extents, which can be many times greater than the thickness. The thickness is as similar as possible, preferably substantially the same, over the entire surface area of ​​the self-adhesive product determined by the length and width.

[0135] Typical converted forms of the self-adhesive products according to the invention are adhesive tape rolls and self-adhesive strips, which are obtained, for example, in the form of die-cut pieces.

[0136] Preferably, all layers are substantially in the shape of a cuboid. More preferably, all layers are bonded to each other over the entire area.

[0137] Optionally, a non-adhesive grip sheet area can be provided, from which the separation process can begin.

[0138] The self-adhesive product preferably has a thickness of 20 μm to 2000 μm, further preferably 30 to 1500 μm, particularly preferably 50 to 1000 μm or 100 μm, 150 μm, 200 μm, 250 μm or 500 μm, the temporary carrier material not being included.

[0139] Preferred is an embodiment of the self-adhesive product in which the permanent carrier has a thickness between 20 and 100 μm, preferably 30 to 60 μm, and the identical pressure-sensitive adhesive layers of the invention on the permanent carrier each have a thickness between 20 and 100 μm, preferably 30 to 60 μm.

[0140] Furthermore, preferred are embodiments of the self-adhesive product in which no permanent carrier is included and the pressure-sensitive adhesive of the invention is present in a single layer on a temporary carrier material. The pressure-sensitive adhesive layer preferably has a thickness between 100 μm and 2000 μm, in particular between 200 μm and 1500 μm or between 400 μm and 1200 μm.

[0141] Preferably, the self-adhesive product according to the invention which is releasable by stretching can be removed by stretching it preferably substantially in the adhesive plane, ie at an angle of about 0°, whereby it can be releasable without residue and without damage.

[0142] However, removal is also possible at other removal angles, such as 45° or 90°.

[0143] Manufacturing method

[0144] The pressure-sensitive adhesive for the self-adhesive product according to the invention is applied to one side of a temporary carrier material or to one side of a permanent carrier. The pressure-sensitive adhesive can be applied to the carrier according to methods known to those skilled in the art, for example by a scraper method, a nozzle scraper method, a rolling rod nozzle method, an extrusion nozzle method, a casting nozzle method and a casting method. Also according to the invention are application methods such as roller coating methods, printing methods, screen printing methods, screen roller coating methods, inkjet methods and spraying methods.

[0145] Preferred coating variants are based on solvents. For this reason, the components of the pressure-sensitive adhesive are dissolved in a suitable solvent or solvent mixture, then coated from the solution, and the coated material is dried. Suitable solvents that can also be used in combination are aliphatic compounds (e.g. pentane, hexane, heptane, octane and structural isomers thereof), alicyclic compounds (e.g. cyclohexane and methylcyclohexane) and aromatic hydrocarbons (e.g. toluene, xylene), particularly in combination with ketones (e.g. acetone, 2-butanone, isobutyl ketone) or esters (e.g. ethyl acetate, butyl acetate, propyl acetate, isopropyl acetate). In an advantageous procedure, a mixture of toluene and ethyl acetate is used. A mixture of methylcyclohexane and an ester such as ethyl acetate or particularly butyl acetate is very advantageous. A mixture of cyclohexane and an ester, particularly butyl acetate is also advantageous.

[0146] Another preferred manufacturing variant is a hot melt process, in which the pressure-sensitive adhesive is mixed by a compounding unit and then applied directly ("on-line") to the carrier material, particularly by extrusion and / or nozzle and / or calender. However, the application method is not necessarily the kind of direct coating. The pressure-sensitive adhesive may also be first coated in a different manner and then laminated to the carrier in a second step. Subsequently, if desired, a layer or sheet of other material may be coated or laminated online or off-line, thereby also multi-layer / multi-ply product structure may be manufactured. These other layers may introduce specific additional properties, such as mechanical properties, for self-adhesive products. They may also promote the anchoring between adhesive and carrier, or suppress the migration of a single component from one layer to another layer.

[0147] For product structures with a permanent carrier, the pressure-sensitive adhesive layer can be applied by direct coating onto the permanent carrier material or by lamination, in particular hot lamination.

[0148] use

[0149] The self-adhesive products according to the invention are very suitable for long-term stable permanent bonds, where a high hot shear strength as well as the separability of the bonded assembly is required even after storage under hot and humid conditions.

[0150] The releasability of the permanent bond may be required for rework purposes (if the bond is to be corrected during the manufacture of the article), repair purposes (if a defective part of the bonded assembly is to be replaced) or recycling purposes (if the bonded assembly is to be disposed of as a separate material after its service life has ended). Self-adhesive products with the pressure-sensitive adhesive described herein have also proven to be advantageous, in particular with respect to polar surfaces such as steel and low-energy surfaces such as PP / EPDM, PP / EPM and PP / EPR. Therefore, another subject of the present invention is the use of the pressure-sensitive adhesive of the present invention or the adhesive tape of the present invention for bonding substrates comprising ethylene (co) polymers, propylene (co) copolymers, EPR, EPM and / or EPDM or other plastics. In particular, the pressure-sensitive adhesive of the present invention or the adhesive tape of the present invention is used to bond mounting parts comprising ethylene (co) polymers, propylene (co) copolymers, EPR, EPM and / or EPDM or other plastics such as ABS or polycarbonate in or on a car / vehicle. The life of the pressure-sensitive adhesive of the present invention also allows bonding of other materials such as glass, ceramics and metals.

[0151] The present invention therefore further provides for the use of the pressure-sensitive adhesive of the invention or the adhesive tape of the invention for bonding other substrates, such as, in particular, other plastics and metals.

[0152] Therefore, another subject of the present invention is also a glued composite material comprising at least one self-adhesive product according to the invention and at least one substrate in contact with the at least one adhesive layer of the self-adhesive product.

[0153] A further subject matter of the present invention is an adhesively bonded assembly comprising at least two substrates and at least one self-adhesive product according to the invention which bonds the two substrates to one another.

[0154] A further subject matter of the invention is an assembly of a single-sided self-adhesive product and a substrate which is in contact with at least one pressure-sensitive adhesive layer of the single-sided self-adhesive product.

[0155] All of the above observations apply to both substrates and self-adhesive products.

[0156] The present invention is explained in more detail using the following examples, which should not be understood as limiting the concept of the present invention in any way.

[0157] Test Method

[0158] Unless expressly stated otherwise, measurements were performed under test conditions of 23±1° C. and 50±5% relative humidity.

[0159] Test I—Molar Mass (GPC)

[0160] (a) Peak molar mass of each block copolymer mode

[0161] In terms of molecular weight distribution, polymers are multimodal systems (polymodal systems, multimodal systems). Mixtures of different polymers can be understood as multimodal systems, wherein each polymer contributes its own molar mass distribution. Mixtures of block copolymers with structures having different molar mass distributions can also be understood as multimodal systems. Then, each block copolymer produces its own molar mass distribution. For simplicity, these are referred to as block copolymer modes herein.

[0162] GPC is a metrological method for determining the molar mass of individual polymer modes in a mixture of different polymers. For block copolymers produced by living anionic polymerization that can be used in the sense of the present invention, the molar mass distribution is generally narrow enough so that the polymer modes that can be assigned to triblock copolymers, diblock copolymers or multiblock copolymers are well resolved from each other in the elution diagram (elugram). The peak molar mass of each polymer mode can then be read from the elution diagram.

[0163] The peak molar mass (peak MM) was determined by gel permeation chromatography (GPC). The eluent used was THF. The measurement was carried out at 23°C. The pre-column used was PSS-SDV, 5μ, ID 8.0mm x 50mm. For separation, the column used was PSS-SDV, 5μ, as well as and Each had an ID of 8.0 mm x 300 mm. The sample concentration was 4 g / l and the flow rate was 1.0 ml / min. The calibration was performed using the commercially available ReadyCal kit Poly(styrene) high from PSS Polymer Standard Service GmbH, Mainz (μ = μm; ).

[0164] (b) Weight average molar mass, in particular the weight average molar mass of the plasticizer

[0165] Weight average molecular weight M W Determined by gel permeation chromatography (GPC). The eluent used was THF. The measurement was carried out at 23°C. The pre-column used was PSS-SDV, 5μ, ID 8.0mm x 50mm. For separation, the column used was PSS-SDV, 5μ, as well as and Each had an ID 8.0 mm x 300 mm. The sample concentration was 4 g / l and the flow rate was 1.0 ml / min. The calibration was performed using the commercially available ReadyCal kit Poly(styrene) high from PSS Polymer Standard Service GmbH, Mainz.

[0166] Test II - Peel Adhesion, Steel

[0167] The determination of peel adhesion (according to AFERA ​​5001) is carried out as follows. The specified adhesive substrate used is a polished steel plate with a thickness of 2mm. Unless otherwise stated, the bondable sheet-like element to be checked (500μm pressure-sensitive adhesive layer as a transfer adhesive layer is reinforced with 75μm polyester film on the back) is cut into a width of 20mm and a length of about 25cm, a grip section is provided, and immediately afterwards, a 4kg steel roller is used to press 5 times on the corresponding selected adhesive substrate at a forward speed of 10m / minute. Immediately thereafter, the bondable sheet-like element is peeled off from the adhesive substrate at an angle of 180° with a tensile tester (from Zwick) at a speed of v=300mm / minute, and the force required for this purpose is measured at room temperature. The measured value (in N / cm) is obtained as the average value from three independent measurements.

[0168] Test III - Tear Resistance

[0169] For the tear resistance test, the tape specimens were prepared as follows. A 500 μm pressure-sensitive adhesive coating was tested as a single-layer adhesive strip specimen. Ten strips each 12 mm wide and 55 mm long were prepared from the adhesive tape to be tested, which were formed into an isosceles triangle over a length of 10 mm on one side.

[0170] These strips are bonded to a polycarbonate sheet conditioned with ethanol over a length of 45 mm so that a 10 mm long tab protrudes, which is located opposite the side indicated by the isosceles triangle; i.e., at the rectangular end of the strip. A second polycarbonate sheet is applied to the second surface of the bonded strips so that the two polycarbonate sheets are flush one on top of the other. The assembly is rolled ten times (five times forward and backward) using a 4 kg roller. After a bonding time of 24 hours, the strips are manually peeled off from the glued joint using the tab at an angle of 180 °.

[0171] An assessment is made as to how many specimens can be separated again without residue. The tear resistance is reported as a percentage of torn adhesive strips. 0% corresponds to the case in which none of the 10 adhesive strips was torn during the separation test by stretching. 80% corresponds to the case in which 8 of the 10 adhesive strips were torn during the separation test by stretching.

[0172] After the adhesion period, the assemblies were exposed to different storage conditions: (a) 7 days at 85°C, (b) 7 days at 85°C and 85% relative humidity. The assemblies were then conditioned at 23°C and 50% relative humidity for 24 hours before tear resistance measurements.

[0173] Test IV - (Tackifier) ​​Resin Softening Temperature

[0174] For each substance: (Tackifier) ​​The softening temperature of the resin (softening point) was determined according to a method known as the Ring & Ball method and standardized according to ASTM E28.

[0175] Testing V-DACP

[0176] 5.0 g of the test substance (tackifier resin sample to be checked) are weighed into a dry test tube (sample glass) and 5.0 g of xylene (isomer mixture, CAS [1330-20-7], ≥98.5%, Sigma-Aldrich #320579 or the like) are added. The test substance is dissolved at 130° C. and the solution is then cooled to 80° C. If xylene escapes, it is replenished with further xylene so that 5.0 g of xylene are present again. 5.0 g of diacetone alcohol (4-hydroxy-4-methyl-2-pentanone, CAS [123-42-2], 99%, Aldrich #H41544 or the like) are then added. The test tube is shaken until the test substance has completely dissolved. For this purpose, the solution is heated to 100° C. The test tube containing the resin solution is then placed in a Novomatics Chemotronic Cool turbidity measuring instrument, where it is heated to 110° C. Cooling is carried out at a cooling rate of 1.0 K / min. The cloud point is detected optically. For this purpose, the temperature at which the turbidity of the solution is 70% is recorded. The results are reported in ° C. The lower the DACP value, the more polar the test substance.

[0177] Test VI – MMAP

[0178] 5.0 g of the test substance (tackifier resin sample to be checked) are weighed into a dry test tube and 10 mL of dry aniline (CAS [62-53-3], ≥99.5%, Sigma-Aldrich #51788 or analogue) and 5 mL of dry methylcyclohexane (CAS [108-87-2], ≥99%, Sigma-Aldrich #300306 or analogue) are added. The test tube is shaken until the test substance has completely dissolved. For this purpose, the solution is heated to 100° C. The test tube containing the resin solution is then placed in a Novomatics Chemotronic Cool turbidity point measuring instrument, in which it is heated to 110° C. Cooling is carried out at a cooling rate of 1.0 K / min. The turbidity point is detected optically. For this purpose, the temperature at which the turbidity of the solution is 70% is recorded. The results are reported in ° C. The lower the MMAP, the higher the aromaticity of the test substance.

[0179] Test VII - Peel Force

[0180] The separation force (peel force or peel stress) is determined using a sample of the item to be checked, more particularly a self-adhesive product or a permanent carrier having dimensions of 50 mm long × 20 mm wide and having a non-adhesive gripping ear area at the upper end. The sample is bonded between two superimposed steel plates having dimensions of 50 mm × 30 mm using a contact pressure of 50 Newtons in each case. At their lower ends, the steel plates each have a hole for receiving an S-shaped steel hook. The lower end of the steel hook carries an additional steel plate, which can be used to fix the test arrangement for measurement in the lower clamp of a tensile testing machine. The bond is stored at +40°C for a period of 24 hours. After readjustment to room temperature, the sample strip is peeled (extracted) at a pulling speed of 1000 mm / min, parallel to the bonding plane and without contacting the edge areas of the two steel plates. The required separation force in Newtons (N) is measured. The average value of the peel stress values ​​(in N / mm 2 The average value of the self-adhesive product is measured in the area (range) where the self-adhesive product has been separated from the steel substrate over a bond length of between 10 mm and 40 mm.

[0181] Test VIII - Extensibility, Resilience

[0182] To measure the resilience, the corresponding article, in particular a self-adhesive product or a permanent carrier, is extended by 100%, held at this extension for 30 seconds and then released. After a waiting time of 1 minute, the length is measured again.

[0183] Then the rebound resilience is calculated as follows: RV = ((L 100 –L 结束 ) / L 0)·100, where RV = rebound resilience in %.

[0184] L 100 : Length of adhesive strip after 100% extension

[0185] L 0 : Length of adhesive strip before extension

[0186] L 结束 : Length of adhesive strip after 1 minute of relaxation.

[0187] The resilience here corresponds to the elasticity.

[0188] Elongation at break, tensile strength and stress at 50% elongation were measured using size S3 dumbbell test pieces at a separation speed of 300 mm / min in accordance with DIN 53504. The test conditions were 23° C. and 50% relative air humidity.

[0189] Test IX - Polyvinyl Aromatic Compound Fraction

[0190] Unless otherwise known, the fraction of polyvinyl aromatic blocks in a hydrogenated polyvinyl aromatic-polydiene block copolymer is determined by 13 C-NMR measurement. The following uses, for example, the determination of the polystyrene fraction in a hydrogenated polystyrene-polydiene block copolymer (SEPS) to illustrate 13 C-NMR. 13 C spectrum, the average is formed from two integrals, namely the styrene-C signal at about 144 to 146 ppm and the styrene-CH at about 125 to 127 ppm. For SEBS, this average is set in relation to the butene integral (hydrogenated 1,2-polybutadiene repeating unit), namely the CH3 signal at about 10 ppm, and to the ethylene integral (hydrogenated 1,4-polybutadiene repeating unit), which can be obtained by calculation from the total olefin integral at about 20 to 50 ppm. The fraction thus obtained in mol % is then converted into wt %.

[0191] I. Raw materials used

[0192] Table 2: Chemicals used

[0193]

[0194]

[0195] SEPS: Styrene-ethylene / butylene-styrene block copolymer

[0196] PS fraction: Polystyrene fraction

[0197] Peak MW: Peak molecular weight

[0198] Peak MW*: Peak molecular weight of the triblock copolymer

[0199] HC resin: hydrocarbon resin

[0200] Soft.point: Softening point

[0201] M W : Weight average molecular weight

[0202] II. Experiment

[0203] A series of test tape specimens were prepared.

[0204] Manufacturing method (hot melt method):

[0205] The solvent-free manufacture of the pressure-sensitive adhesive formulation is carried out by means of a planetary roll extruder (PWE), which includes an inlet area and two processing sections. The run-in rings have an increasing diameter in the processing direction. Although different spindle accessories are suitable, at least 3 / 4 of the accessories of the maximum number of accessories in the first processing section are preferred. The elastomer component and the reinforcing component are metered in the inlet of the PRE. The resin component is melted and added in the first processing section of the PWE. A particularly suitable means for the manufacture of a uniform mixture is a resin split, in which a portion of the resin is added in the inlet area, and the remaining portion is added downstream of the first processing section. It is particularly suitable to add two fractions in liquid form via side feeds or start-up rings, the first fraction being about 30% by weight of the total amount of resin, and unless otherwise specified, the process is implemented in this manner. It is also suitable to add the first resin fraction in solid form in the inlet of the PWE or via a side feed in the inlet area.

[0206] The coating was carried out by introducing the hot pressure-sensitive adhesive into a 2-roll calender to a thickness of 500 μm.

[0207] The properties listed in the table were then tested using a 500 μm thick adhesive transfer tape.

[0208] The examples marked with "I" are examples according to the present invention. The examples marked with "C" are comparative examples.

[0209] Table 3

[0210]

[0211] Table 4

[0212]

[0213] Table 5

[0214]

[0215]

[0216] Surprisingly, the examples according to the invention comprising a reinforcing component in combination with other ingredients showed an improvement in separation properties compared to the control system without such a reinforcing component, in which case they could be separated without tearing. Surprisingly, the separation properties were improved, in particular after storage of the corresponding adhesive assemblies under hot and humid conditions, although there was no difference in the tearing properties when stored only at temperature (also 85° C.).

Claims

1. Pressure-sensitive adhesive, including: a) at least 28 wt. % and at most 60 wt. % of an elastomeric component, wherein i. the elastomeric component comprises at least 60% by weight and preferably up to 90% by weight of at least one hydrogenated polyvinylaromatic-polydiene block copolymer having a polyvinylaromatic fraction of at least 18% by weight and a peak molecular weight determined by GPC of from 100 000 to 500 000 g / mol (Test I), based in each case on the elastomeric component, ii. the polydiene blocks are substantially fully hydrogenated, iii. The hydrogenated polyvinyl aromatic compound-polydiene block copolymer has an ABA structure, wherein n=2 (AB) n Z structure or radial (AB) where n≥3 n Structure or radial (AB) n -Z structure, wherein A=polyvinyl aromatic compound, B=ethylene and butene or ethylene and propylene, and Z=derivative of coupled substance, and wherein the ethylene fraction in the B block is preferably at least 50% by weight, and iv. The elastomer component comprises at least one (A'B') having an A'B' structure or wherein n=1 n A hydrogenated diblock copolymer of structure Z, wherein A'=polyvinyl aromatic compound, B'=ethylene and butene or ethylene and propylene, Z=derivative of coupled substance, and possibly A'=A and B'=B, b) a tackifier resin component, c) optionally a plasticizer component, d) at least 2.5% to 22% by weight, preferably at least 4% to 18% by weight, of a reinforcing component of at least one resin having an MMAP value between -10°C and +30°C, preferably between 0°C and +20°C, and a softening point of at least 140°C, e) optionally further auxiliaries, The fraction of the elastomeric component is based on the total weight of the pressure sensitive adhesive.

2. The pressure-sensitive adhesive according to claim 1, comprising: c) at least 2 wt % and no more than 25 wt % of a plasticizer component.

3. The pressure-sensitive adhesive according to claim 1 or 2, characterized in that The fraction of the elastomeric component in the layer of pressure-sensitive adhesive is 35% to 58% by weight, preferably 40% to 52% by weight, based in each case on the total weight of the pressure-sensitive adhesive.

4. The pressure-sensitive adhesive according to any one of the preceding claims, characterized in that The polyvinyl aromatic-polydiene block copolymer has a polyvinyl aromatic fraction of 18 to 35% by weight, preferably 20 to 33% by weight.

5. The pressure-sensitive adhesive according to any one of the preceding claims, characterized in that The at least one resin of the reinforcing component is a resin based on at least one, in particular aromatic, hydrocarbon compound, preferably selected from styrene, α-methylstyrene, p-methylstyrene and copolymers thereof, wherein the at least one resin of the reinforcing component preferably has a weight average molecular weight M of 1000 to 15 000 g / mol, preferably 2000 to 10 000 g / mol, as determined by GPC. w .

6. A pressure-sensitive adhesive according to any one of the preceding claims, characterised in that The elastomeric component comprises up to 35% by weight, preferably 10% to 30% by weight, of at least one hydrogenated diblock copolymer, based on the elastomeric component.

7. The pressure-sensitive adhesive according to claim 6, characterized in that The at least one diblock copolymer has a peak molecular weight of <100 000 g / mol as determined by GPC.

8. A pressure-sensitive adhesive according to any one of the preceding claims, characterised in that The fraction of the tackifier resin component is 28% to 55% by weight, preferably 35% to 50% by weight, based in each case on the total weight of the pressure-sensitive adhesive.

9. The pressure-sensitive adhesive according to any one of the preceding claims, characterized in that The at least one tackifier resin of the tackifier resin component is chosen from resins based on dicyclopentadiene, hydrocarbon resins based on C5, C5 / C9 or C9 monomer streams, polyterpene resins based on α-pinene and / or β-pinene and / or δ-limonene and polymers of pure C8 or C9 aromatic compounds, the resins being partially or in particular fully hydrogenated.

10. The pressure-sensitive adhesive according to any one of the preceding claims, characterized in that The fraction of the plasticizer component in the pressure-sensitive adhesive is 2% to 20% by weight, particularly preferably 4% to 15% by weight, in each case based on the total weight of the pressure-sensitive adhesive.

11. The pressure-sensitive adhesive according to any one of the preceding claims, characterized in that The plasticizer component is at least one plasticizer selected from the group consisting of ethylene / propylene copolymers, ethylene / butene copolymers, and butene / isobutylene (co)polymers.

12. The pressure-sensitive adhesive according to claim 11, characterized in that The plasticizer has a weight-average molar mass of at least 3000 g / mol and at most 20 000 g / mol and is a butene / isobutene (co)polymer.

13. A self-adhesive product which can be separated again by stretching, comprising at least one layer of a pressure-sensitive adhesive according to any one of claims 1 to 12 and at least one ply of a temporary carrier material.

14. The self-adhesive product that can be separated again by stretching according to claim 13, characterized in that The self-adhesive product comprises at least one ply of an extensible permanent carrier material.

15. The self-adhesive product that can be separated again by stretching according to claim 14, characterized in that The extensible permanent carrier material is a stretchable film, which is preferably made of at least one material selected from the following: polyolefins, such as ethylene, propylene, butene and / or hexene, polyurethanes, polyester polyurethanes, polyether polyurethanes, polycaprolactone polyurethanes, ethylene-vinyl acetate (EVA) copolymers and rubber-based materials.

16. The self-adhesive product that can be separated again by stretching according to any one of claims 13 to 15, characterized in that The self-adhesive product is a single-layer double-sided self-adhesive tape consisting of a single layer of the pressure-sensitive adhesive according to any one of claims 1 to 12, or - a multilayer double-sided self-adhesive tape, wherein each layer consists of a pressure-sensitive adhesive according to any one of claims 1 to 12, or a multilayer, double-sided self-adhesive tape having a permanent carrier, the carrier being arranged in a layer of a pressure-sensitive adhesive according to any one of claims 1 to 12 or between two layers of a pressure-sensitive adhesive according to any one of claims 1 to 12, - a multilayer, single-sided self-adhesive tape having at least one layer of a pressure-sensitive adhesive according to any one of claims 1 to 12 and a permanent carrier, - in each case in combination with a temporary carrier material.

17. The self-adhesive product that can be separated again by stretching according to any one of claims 13 to 16, characterized in that The self-adhesive product consists of a single-layer permanent support, preferably comprising a polyolefin, wherein the support has an elongation at break of at least 100%, preferably at least 300%, and optionally a resilience of less than 50%, and The carrier carries on both sides respectively applied layers of a pressure-sensitive adhesive according to any one of claims 1 to 12, wherein preferably the composition of the adhesives is identical.

18. The self-adhesive product that can be separated again by stretching according to any one of claims 13 to 16, characterized in that The self-adhesive product consists of a single-layer permanent support, preferably consisting of polyurethane, wherein said support has an elongation at break of at least 100%, preferably at least 300%, and optionally a resilience of more than 50%, and The carrier carries on both sides respectively applied layers of a pressure-sensitive adhesive according to any one of claims 1 to 12, wherein preferably the composition of the adhesives is identical.

19. Adhesive-bonded assembly comprising at least one self-adhesive product according to any one of claims 13 to 18 and at least one substrate in contact with at least one layer of a pressure-sensitive adhesive according to any one of claims 1 to 12.

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