Photocured reactive adhesive film

Abstract

The present invention relates to photocured reactive pressure-sensitive adhesive films. Using the adhesive films of the present invention, structural adhesion strength can be achieved. The adhesive films include (a) at least one reactive monomer or reactive resin, (b) an initiator, (c) a photo-oxidation-reduction catalyst, (d) a polymer of a monomer including an N-vinyl compound, and (e) a film-forming polymer.

Description

TECHNICAL FIELD

[0001] The present invention relates to a light-cured reactive pressure-sensitive adhesive film of an adhesive, the curing of which is initiated by blue LED light or UV-LED light. The adhesive film comprises (a) at least one reactive monomer or reactive resin, (b) an initiator, more particularly a free-radical initiator, (c) a photo-oxido-reduction catalyst, (d) a polymer of a monomer comprising an N-vinyl compound, and (e) a film-forming polymer. In addition, a process for the production of the inventive reactive adhesive film as described above is provided. With the adhesive film of the present invention, it is possible to achieve structural adhesive strength. The adhesive film can be used for bonding a variety of materials, such as plastics, metals, glass and / or ceramics. The bonding using the adhesive film is notable for high adhesive strength and high resistance to combined heat and humidity. BACKGROUND

[0002] Two-component adhesive systems based on acrylic monomers have been known for many years, in particular, and are described in detail in the technical literature. In these free-radically polymerized systems, an adhesive film system consisting of two components is applied to the parts to be bonded, and usually two liquid components are used. For example, one component consists of the monomers to be polymerized and an activator, and the other component consists of a free-radical-forming substance, also referred to as curing agent or initiator, and monomers to be polymerized. After the two components are mixed or at least brought into contact, the chemical reaction of the activator with the free-radical-forming substance produces at least one free radical, and the polymerization reaction of the monomers to be polymerized begins. Subsequently, a free-radical chain polymerization of the monomers takes place until the chain termination point, and the adhesive is thus cured, whereby permanent bonding of the parts to be bonded is achieved.

[0003] Two-component adhesive systems based on acrylic monomers are likewise known in the form of pressure-sensitive adhesive films (adhesive tapes). They are described, for example, in EP 300847 A1, EP 3010989 A1, EP 3063243 A1, WO 2018104053 A1 and EP 3328951 A1. A major disadvantage of these films is the fact that there are two films that have to be brought into contact in a form-fitting manner, and this can become problematic, in particular, when the surfaces to be bonded are very long and narrow and the corresponding adhesive film must therefore also be very long and narrow.

[0004] One-component adhesive films based on acrylic monomers are likewise part of the generally known prior art. These are usually cured with light, in particular UV light. In this case, the curing reaction is initiated by means of a photoinitiator, which, after absorption of the (UV) light, decomposes in a photolysis reaction and thus forms reactive species which initiate the radical polymerization. The disadvantage here is the rapidity of the curing reaction, in particular if the substrates to be bonded are not transparent. Once the reaction has been initiated, there is usually no longer enough time to join the components to be bonded. This adhesive film is therefore only suitable for the bonding of (UV) transparent substrates, since in this case the irradiation can take place through the components after they have been joined. A further disadvantage of this type of adhesive film is that the polymerization does not continue as a dark reaction.

[0005] DE 102019209513 A1 describes an adhesive film based on acrylic monomers which does not exhibit the described disadvantages of the prior art. The disadvantage occurring here is insufficient resistance to heat and moisture for many applications.

[0006] EP 3390553 A1 proposes a method in which an adhesive tape consisting of two mutually reactive layers A and B separated from one another by a barrier layer is reacted and thereby cured by means of a laser, wherein the barrier layer is removed by exposure to the laser. The disadvantage here is the need for a laser.

[0007] EP 3126402 A1 discloses a method in which a radical polymerization reaction is initiated by means of a plasma treatment of an adhesive which comprises one substance which is reactive in the radical polymerization reaction and a further substance which catalyzes the reactivity. With this method, a sufficiently slow curing rate can be achieved. The disadvantage is that plasma devices suitable for achieving good bond strengths are not yet widely available on the market. In addition, the achievable bond strength results depend on parameters which are difficult to influence in some cases, such as air humidity. SUMMARY

[0008] Object of the present application

[0009] The present application is therefore based on the object of providing an improved, light-cured, reactive, pressure-sensitive adhesive film with which a high (so-called structural) bond strength can be achieved with high resistance to heat and moisture of the assembly. The curing can be initiated by means of blue LED light or UV-LED light. The adhesive film is cured sufficiently slowly to allow the components to be bonded to have a certain time interval to be joined after initiation, so that also non-transparent components can be bonded well. After initiation and joining of the components, the adhesive film will also continue to cure in the dark.

[0010] Achievement of the object

[0011] This object is achieved by a photocured 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 obtained by free-radical polymerization of carbon-carbon double bond containing monomers, characterized in that these monomers comprise N-vinyl compounds; and (e) a film-forming polymer. DETAILED DESCRIPTION

[0012] The present invention relates to a photocured 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 obtained by free-radical polymerization of carbon-carbon double bond containing monomers, characterized in that these monomers comprise N-vinyl compounds; and (e) a film-forming polymer. The photocured reactive pressure-sensitive adhesive film is preferably based on acrylic monomers. The curing is initiated by blue LED light or UV-LED light, and the adhesive film of the present invention is preferably cured slow enough to allow the assembly to be bonded to be joined for a certain time interval after initiation if necessary, for example if an opaque substrate is to be bonded, and to continue curing even in the dark after bonding.

[0013] Reactive monomer or reactive resin

[0014] As used herein, reactive monomer or reactive resin is intended to mean a monomer or resin that is particularly capable of undergoing free-radical chain polymerization.

[0015] Suitable reactive monomers or reactive resins are selected from at least one representative of the following: acrylates, such as 2-ethylhexyl acrylate, methacrylates, vinyl compounds and / or oligomeric or polymeric compounds having carbon-carbon double bonds, and crosslinking reactive monomers, such as diacrylates, dimethacrylates, triacrylates, trimethacrylates, higher functionality acrylates and higher functionality methacrylates. The reactive resins chosen can comprise oligomeric compounds having acrylate or methacrylate functionality, in which case the functionalization can be single or multiple. Very advantageously, they are used in mixture with at least one reactive monomer.

[0016] Preferred monomers in terms of high bond strength are acrylates and / or methacrylates in which the alcohol part of the ester comprises an aromatic structural element, a heteroatom or a functional group. Preferred are urethane groups, urea groups, oxygen or nitrogen heterocycles, ether groups, ester groups, acid functional groups and / or hydroxyl functional groups. Also preferred in terms of good resistance to heat and moisture of the combination are acrylates and / or methacrylates in which the alcohol part of the ester is an aliphatic alcohol. In terms of high crosslinking density, further preferred are crosslinking monomers.

[0017] Examples of preferred monomers are 2-phenoxyethyl acrylate (CAS No.: 48145-04-6), 2-phenoxyethyl methacrylate (CAS No.: 10595-06-9), 2-hydroxy-3-phenoxypropyl acrylate (CAS No.: 16969-10-1), 2-hydroxy-3-phenoxypropyl methacrylate (CAS No.: 16926-87-7), 2-[2-(methacryloyloxy)ethoxycarbonyl]benzoic acid (CAS No.: 27697-00-3), 2-[[(phenylamino)carbonyl]oxy]ethyl methacrylate (CAS No.: 51727-47-0), 2-tert-butyl-6-[(3-tert-butyl-2-hydroxy-5-methylphenyl)methyl]-4-methyl-phenyl ester (CAS No.: 61167-58-6), and 5-ethyl-1,3-diethyl acrylate. Alkyl-5-yl)methyl methacrylate (CAS No. 66492-51-1), (2-oxo-1,3-dioxolane-4-yl)methyl methacrylate (CAS No.: 13818-44-5), di(ethylene glycol) 2-ethylhexyl ether acrylate (CAS No.: 117646-83-0), (2,2-dimethyl-1,3-dioxolane-4-yl)methyl acrylate (CAS No.: 13188-82-4), mono-[2-(acryloyloxy)ethyl succinate] (CAS No.: 50940-49-3), mono-[2-(methacryloyloxy)ethyl succinate] (CAS No.: 20882-04-6), (2,2-pentamethylene-1,3-yl)methyl methacrylate 2-hydroxy-3-(prop-2-enoyloxy)propyl 2-methyl-2-propyl hexanoate (CAS No.: 444649-70-1), 2-[[(butylamino)carbonyl]oxy]ethyl acrylate (CAS No.: 63225-53-6), stearyl acrylate (CAS No.: 4813-57-4), stearyl methacrylate (CAS No.: 32360-05-7), and the crosslinking reactive monomer diaminodicylate dimethacrylate (isomer mixture) (CAS No.: 72869-86-4), bisphenol A glyceryl dimethacrylate (BIS-GMA, CAS No.: 1565-94-2), bisphenol A dimethacrylate (BIS-DMA, CAS No.: 3253-39-2), ethylene glycol diacrylate (CAS No.: 2274-11-5), ethylene glycol dimethacrylate (CAS No.: 97-90-5), trimethylolpropane propoxylate triacrylate (CAS No.: 53879-54-2), trimethylolpropane triacrylate (CAS No.: 15625-89-5) and / or di(trimethylolpropane) tetraacrylate (CAS No.: 94108-97-1). Particularly preferred are 2-hydroxy-3-phenoxypropyl acrylate, 2-[[(butylamino)carbonyl]oxy]ethyl acrylate and diaminodicylate dimethacrylate.

[0018] The fraction of the reactive monomer(s) and / or the reactive resin(s) is preferably in the range of about 10 to 80 weight percent (wt.-%), more preferably about 20 to 60 weight percent, based on the total mixture of the ingredients of the reactive adhesive film of the present application. Most preferably, about 30 to 50 weight percent of the reactive monomer(s) and / or the reactive resin(s) are used, based on the total mixture of the ingredients of the reactive adhesive film of the present application. Here, the total mixture of the ingredients of the reactive adhesive film of the present application represents the total amount of (a) reactive monomer(s) / reactive resin(s), (b) initiator(s), (c) photo-oxidation-reduction catalyst(s), (d) polymer of monomers comprising N-vinyl compounds, (e) film-forming polymer(s), and optionally further optional ingredients, which is obtained as a sum in weight percent (wt.-%). Solvents and / or water are only used for the manufacture and, thus, are not considered as part of the total mixture of the ingredients of the reactive adhesive of the present application. The same applies for solvents already contained in commercially available raw materials.

[0019] initiator, in particular free radical initiator

[0020] As used herein, the term "initiator", more particularly a radical initiator or radical-forming substance, represents a compound which is able to initiate the polymerization reaction or crosslinking polymerization of the adhesive film. However, the initiator, more particularly the radical initiator, participates in the reaction to a very small extent and thus does not form polymer fragments which determine the properties of the adhesion.

[0021] In the present application, an initiator, more particularly a radical initiator, is added to the reactive adhesive film of the present application. The initiator is preferably selected such that it does not initiate polymerization at temperatures up to 90°C in a mixture with the reactive monomers and / or reactive resins, even if the mixture is irradiated with UV or blue light. This is the case as long as no photo-oxidation reduction catalyst or other activating compounds are added to the mixture.

[0022] A radical initiator is preferred. Thus, in a preferred embodiment, the photocured reactive pressure-sensitive adhesive film of the present application comprises a radical initiator as initiator (b). All radical initiators known in the prior art can be used. Preferred radical initiators are peroxides, more particularly hydroperoxides.

[0023] In a particularly preferred embodiment of the present application, the radical initiator is an organic peroxide, such as a peroxycarboxylic acid and a hydroperoxide. Hydroperoxides, more particularly diisopropylbenzene hydroperoxide (CAS No. 26762-93-6) are particularly preferred. Diisopropylbenzene hydroperoxide is preferably used in the form of a 50% by weight solution of diisopropyl hydroperoxide in diisopropylbenzene, which is available under the trade name IHP-50 (from Pergan GmbH, Bocholt, Germany). It is also possible to use a,a-dimethylbenzyl hydroperoxide, which is also known as cumene hydroperoxide (CAS No. 80-15-9). Furthermore, it is also possible to use, for example, p-menthane hydroperoxide (CAS No. 26762-92-5), t-amyl hydroperoxide (CAS No. 3425-61-4), t-butyl hydroperoxide (CAS No. 75-91-2) or 1,1,3,3-tetramethylbutyl hydroperoxide (CAS No. 5809-08-5).

[0024] The fraction of free radical initiator is preferably in the range of about 0.1 to 10 wt.-%, more preferably about 0.2 to 4 wt.-%, based on the total mixture of the components of the reactive adhesive film of the present application. Most preferably, about 0.5 to 2 wt.-% of free radical initiator is used, based on the total mixture of the components of the reactive adhesive film. Here, the total mixture of the components of the reactive adhesive film of the present application represents the total amount of (a) reactive monomers / reactive resins, (b) initiators, (c) photo-oxidation-reduction catalysts, (d) polymers of monomers including N-vinyl compounds, (e) film-forming polymers, and optionally further optional components used, which is obtained as a sum in weight percent (wt.-%). Solvents and / or water are only used for manufacturing and thus are not considered part of the total mixture of the components of the reactive adhesive of the present application. The same is true for solvents already contained in commercially available raw materials.

[0025] Photo-oxidation-reduction catalyst

[0026] As used herein, the term "photo-oxidation-reduction catalyst" represents a photo- sensitive compound or UV photo-sensitive compound, which, when excited by light or UV light, can mediate electron transfer between chemical compounds, which would otherwise react more slowly or not at all. In contrast to a photoinitiator, a photo-oxidation-reduction catalyst does not decompose into reactive cleavage (splitting) products upon irradiation with light or UV light, but instead is only in an excited state, which is usually of relatively long lifetime and can initiate or mediate oxidation-reduction processes from it. In a mixture with reactive monomers and / or reactive resins, the photo-oxidation-reduction catalyst preferably does not initiate polymerization at temperatures up to 90°C, even if the mixture is irradiated with UV or blue light. This is the case as long as no free radical initiator or other initiating compounds are added to the mixture. Thus, the photo-oxidation-reduction catalyst is not an initiator. Upon irradiation with UV or blue light, it only activates the initiator, which then initiates polymerization.

[0027] The photo-oxidation-reduction catalyst used can be a photo-oxidation-reduction catalyst known to the person skilled in the art. Many of the most commonly used photo-oxidation-reduction catalysts are, for example, polypyridyl transition metal complexes of ruthenium and iridium, for example, Ru(bpm)3 2+ (tris(2,2'-bipyridine)ruthenium(II) dichloride), Ru(bpz)3 2+ (tris(2,2'-bipyridine)ruthenium(II) dichloride), Ru(bpz)3 2+ (tris(2,2'-bipyridine)ruthenium(II) dichloride), Ru(bpz)3 2+ (tris(2,2'-bipyridine)ruthenium(II) dichloride), Ru(bpz)3 +(e.g. [4,4'-Bis(1,1 -dimethylethyl)-2,2'-bipyridine-N1,N1 ']bis[3,5-difluoro-2-[5- (trifluoromethyl)-2-pyridyl-N]phenyl-C]iridium(III) hexafluorophosphate), Ir(ppy)3, Ir(ppy)2(dtbbpy) + (e.g. [Ir(dtbbpy)(ppy)2][PF6]), Ir(Fppy)3or fac-Ir(ppy)3(fac-tris(2-phenylpyridine)iridium(III)). However, copper complexes can also be used, such as Cu(dap) 2+ (e.g. copper 2,9-bis(4-methoxyphenyl)-1,10-phenanthroline chloride).

[0028] In a preferred embodiment of the present application, the photo-oxidation reduction catalyst is a transition metal catalyst with ruthenium as central atom and bipyridine or mono- or polysubstituted bipyridine derivatives as ligands. In another preferred embodiment of the present application, the photo-oxidation reduction catalyst is a transition metal complex with iridium as central atom and phenylpyridine or mono- or polysubstituted phenylpyridine derivatives as ligands.

[0029] In a particularly preferred embodiment according to the present application, the photo-oxidation reduction catalyst is selected from the following:

[0030] i. tris(2,2'-bipyridyl)ruthenium(II) 2+ , [Ru(bpy)3] 2+ , formula (la):

[0031]

[0032] ii. tris[2-(2,4-difluorophenyl)pyridine]iridium(III), Ir(Fppy)3; CAS No.: 387859-70-3, formula (lb):

[0033]

[0034] iii. tris(2-phenylpyridyl)iridium(III), Ir(ppy)3; CAS No.: 94928-86-6, formula (lc):

[0035]

[0036] A preferred counterion of the cation of formula (la) is chloride. The corresponding commercially available product contains crystallization water. Thus, a particularly preferred embodiment of the photoredox catalyst of formula (la) is tris(2,2'-bipyridyl)ruthenium(II) chloride hexahydrate (CAS No.: 50525-27-4), which is available from CHEMOS GmbH & Co. KG (Altdorf, Germany, http: / / www.chemos.de), and the same applies to the photoredox catalyst of formula (lc). The photoredox catalyst having formula (lb) is available from Strem (Europe) (Bischheim, France, http: / / www.strem.com).

[0037] The fraction of photoredox catalyst is preferably in the range of at most about 1 wt.-%, more preferably at most 0.5 wt.-%, based on the total mixture of the ingredients of the reactive adhesive film of the present application. Most preferably, about 0.01 - 0.1 wt.-% of photoredox catalyst is used, based on the total mixture of the ingredients of the reactive adhesive film. Here, the total mixture of the ingredients of the reactive adhesive film of the present application represents the total amount of (a) reactive monomers / reactive resins, (b) initiators, (c) photoredox catalyst, (d) polymer of monomers including N-vinyl compounds, (e) film-forming polymers, and optionally further optional ingredients used, which is obtained as a sum in weight percent (wt.-%). Solvents and / or water are only used for manufacturing and thus are not considered part of the total mixture of the ingredients of the reactive adhesive of the present application. The same applies to solvents already contained in commercially available raw materials.

[0038] The photocured reactive pressure-sensitive adhesive adhesive film of the present application preferably does not contain activating or initiating ingredients, or ingredients affecting the activation and initiation process, other than those described in the present specification.

[0039] Polymer of monomers including N-vinyl compounds

[0040] The reactive adhesive film of the present invention comprises a polymer obtained by radical polymerization of carbon-carbon double bond containing monomers, characterized in that these monomers comprise N-vinyl compounds. Typically, 10 wt.-%, 20 wt.-%, 30 wt.-%, 40 wt.-%, 50 wt.-%, 60 wt.-%, 70 wt.-%, 80 wt.-%, 90 wt.-% or 100 wt.-% of the monomers of the polymer consist of N-vinyl compounds. Advantageously, at least 50 wt.-% or at least 80 wt.-%, preferably at least 90 wt.-%, more preferably 100 wt.-% of the monomers of the polymer are N-vinyl compounds. One preferred embodiment of the photocured reactive pressure-sensitive adhesive film of the present invention is characterized in that at least 50 wt.-% of the monomers of the polymer (d) are N-vinyl compounds. More preferably, at least 50 wt.-% or at least 80 wt.-%, and still more preferably 100 wt.-% of the monomers of the polymer (d) are N-vinyl compounds. Here, the term "polymer" is a general (superordinate) term for homo- and copolymers. The polymer obtained by radical polymerization of carbon-carbon double bond containing monomers does not contain carbon-carbon double bonds itself, or only contains such bonds which are formed due to chain termination reactions (disproportionation reactions). It is not a reactive resin. In particular, it cannot undergo radical chain polymerization.

[0041] The carbon-carbon double bond containing monomers are preferably selected from the group consisting of acrylic acid, acrylate esters, methacrylic acid, methacrylate esters and / or vinyl compounds. Particularly preferred are straight-chain alkyl acrylate esters having 2 to 10 carbon atoms in the alkyl group. These are ethyl acrylate, n-propyl acrylate, n-butyl acrylate, n-pentyl acrylate, n-hexyl acrylate, n-heptyl acrylate, n-octyl acrylate, n-nonyl acrylate and n-decyl acrylate. Particularly preferred is n-butyl acrylate.

[0042] Also preferred are branched acyclic acrylate esters having 4 up to and including 12 carbon atoms in the alkyl group of the alcohol. Particularly preferred are 2-ethylhexyl acrylate (EHA), 2-propylheptyl acrylate, isooctyl acrylate, isobutyl acrylate, isoamyl acrylate and / or isodecyl acrylate.

[0043] The N-vinyl compounds of the polymer are advantageously compounds corresponding to formula (II) or comprising structural units of formula (II),

[0044]

[0045] wherein

[0046] - A is an organic radical R or H,

[0047] - B is an organic radical R or H or OR or OH or NR2or NHR or NH2,

[0048] -R is independently and at each occurrence a substituted or unsubstituted branched, cyclic, or straight chain C 1-20 alkyl or C 2-20 alkenyl; or is a substituted or unsubstituted aryl or heteroaryl group,

[0049] A and B can form a ring, for example a lactam or oxazolidinone.

[0050] Examples of such N-vinyl compounds are N-vinylacetamide (CAS No. 5202-78-8), N-vinylcaprolactam (CAS No.: 2235-00-9), N-vinylpyrrolidone (CAS No.: 88-12-0), N-vinyl-N-methylacetamide (CAS No. 3195-78-6), 5-methyl-3-vinyl-2- oxazolidinone (CAS No. 3395-98-0), or N-vinylisobutyramide. Preferred are N-vinyl containing lactams and N-vinyl containing oxazolidinones. If the N-vinyl compound of the polymer (d) is N-vinylcaprolactam (CAS No.: 2235-00-9), N-vinylpyrrolidone (CAS No.: 88-12-0), or 5-methyl-3-vinyl-2- oxazolidinone (CAS No.: 3395-98-0), it is advantageous. Preferably N-vinylcaprolactam or N-vinylpyrrolidone, and in a particularly preferred embodiment, the photocured reactive pressure sensitive adhesive adhesive film is characterized in that the N-vinyl compound of the polymer (d) comprises N-vinylcaprolactam.

[0051] The fraction of the polymer comprising the N-vinyl compound is preferably in the range of about 1 to 50 wt.-%, more preferably in the range of 5 to 30 wt.-%, based on the total mixture of ingredients of the reactive adhesive film of the present application. Even more preferably, 8 to 25 wt.-%, most preferably about 10 to 20 wt.-%, of the polymer comprising the N-vinyl compound are used, based on the total mixture of ingredients of the reactive adhesive film.

[0052] Here, the total mixture of ingredients of the reactive adhesive film of the present application represents the total amount of (a) reactive monomers / reactive resins, (b) initiators, (c) photoredox catalysts, (d) polymers comprising the N-vinyl compound, (e) film-forming polymers, and optionally further optional ingredients used, which is obtained as a sum in weight percent (wt.-%). Solvents and / or water are only used for manufacturing and thus are not considered part of the total mixture of ingredients of the reactive adhesive of the present application. The same applies to solvents already contained in commercially available raw materials.

[0053] Film-forming polymers

[0054] The reactive adhesive film of the present invention comprises a film-forming polymer. It is not desirable to be bound by a particular theory that the film-forming polymer physically binds the reactive monomers / reactive resins and the remaining substances, or restricts their mobility. The film-forming polymer can be said to behave like a sponge, preventing or delaying the flow of the reactive monomers / reactive resins and the remaining substances. Therefore, the polymer is intended to impart its film form to the reactive adhesive film of the present invention and stabilize that form. The film-forming polymer is substantially inert to the reactive monomers / reactive resins and the remaining substances. In this document, inert means that, under suitably selected conditions, more particularly at room temperature (23°C) before photocuring, the reactive monomers / reactive resins substantially do not react with the film-forming polymer.

[0055] Suitable film-forming polymers used in this invention are thermoplastic polymers, such as polyurethanes, polyesters or copolyesters, polyamides or copolyamides, polyacrylates, acrylic / acrylate copolymers (e.g., copolymers of n-butyl acrylate, ethyl acrylate, and acrylic acid), polymethacrylates, and methacrylic / methacrylate copolymers. Chemically or particularly physically crosslinked substances of the above compounds are also conceivable. Blends of different thermoplastic polymers may also be used. Furthermore, elastomers, thermoplastic elastomers, and thermosetting plastics, alone or in combination, are also conceivable as film-forming polymers.

[0056] Preferred thermoplastic polymers are those having a crystallization melt temperature of less than 100°C and / or a softening temperature of less than 100°C. Hereinafter, the term "softening temperature" refers to the temperature at which the thermoplastic granules adhere to themselves. If the film-forming polymer is a semi-crystalline thermoplastic polymer, it very preferably has a glass transition temperature of up to 25°C, and more preferably up to 0°C, in addition to its softening temperature (which relates to the melting of the microcrystals).

[0057] In a preferred embodiment of the invention, a thermoplastic polyurethane is used. Examples of commercially available thermoplastic polyurethanes include those from Covestro AG (Leverkusen, Germany). 530 / 1 and 540 / 3 or from Huntsman (Huntsman Holland BV, Botlek-Rotterdam, Netherlands) S-6558-06 and S 8612 or alternative variants from these product lines. Additionally, there are the following product lines: from BASF (Ludwigshafen, Germany). or Pearlbond from Lubrizol (Lubrizol Advanced Materials Europe BVBA, Brussels, Belgium). The thermoplastic polyurethane preferably has a softening temperature of less than 100°C, more particularly less than 80°C. Preferred examples of such thermoplastic polyurethanes are 530 and S-6558-06. 530 is a hydroxyl-terminated, predominantly (to a large extent) linear, thermoplastic, highly crystalline polyurethane elastomer. According to the manufacturer's instructions, S-6558-06 is a linear thermoplastic polyurethane for solvent-based adhesives. According to the manufacturer's instructions, the features are as follows: very low crystallization rate, long open time, very low activation temperature.

[0058] Particularly preferred is a thermoplastic polyurethane having a very low crystallization rate. Particularly preferred is a thermoplastic polyurethane which shows no signal (peak) for a crystallization melting point in its DSC diagram in the second heating curve between minus 140°C and plus 250°C. In a preferred embodiment, the photocured reactive pressure-sensitive adhesive adhesive film of the present application is characterized in that the film-forming polymer (e) is a thermoplastic polyurethane which shows no signal for a crystallization melting point in its DSC diagram in the second heating curve in the temperature range between minus 140°C and plus 250°C. Here, heating, cooling and reheating each take place at a heating rate of 10 Kelvin per minute (for a sample quantity of 10 mg). The abbreviation DSC stands for the thermal analysis method of differential scanning calorimetry according to DIN EN ISO 11357-1 to -8 (German version: EN ISO 11357-1 :2016, -2:2020, -3:2018, -4:2021, -5:2014, -6:2018, -7:2015 and -8:2021). The method for determining melting and crystallization temperatures as well as melting and crystallization enthalpies is specified in DIN EN ISO 11357-3:2018 (German version).

[0059] In a particularly preferred embodiment of the present application, S-6558-06 is therefore used as a film-forming polymer because it has a very low crystallization rate and shows no signal (peak) for a crystallization melting point in its DSC diagram in the second heating curve in the temperature range between minus 140°C and plus 250°.

[0060] The fraction of the film-forming polymer is preferably in the range of about 10 to 90 wt.-%, more preferably about 20 to 60 wt.-%, based on the total mixture of the components of the reactive adhesive film of the present application. Even more preferably, 30 to 50 wt.-%, most preferably about 35 to 45 wt.-%, of the film-forming polymer are used, based on the total mixture of the components of the reactive adhesive film of the present application. Here, the total mixture of the components of the reactive adhesive film of the present application represents the total amount of (a) reactive monomers / reactive resins, (b) initiators, (c) photo-oxidation reduction catalysts, (d) polymers comprising monomers of N-vinyl compounds, (e) film-forming polymers, and optionally further optional components used, which is obtained as a sum in weight percent (wt.-%). Solvents and / or water are only used for the manufacture and thus are not considered part of the total mixture of the components of the reactive adhesive of the present application. The same is true for solvents already contained in commercially available raw materials.

[0061] Further components of the reactive adhesive film

[0062] The reactive adhesive film of the present application can optionally comprise further additives and / or auxiliaries known in the prior art. The fraction of the further additives and / or auxiliaries can be in the range of about 0 to about 20 wt.-%, preferably 0 to about 15 wt.-%, more preferably 0 to about 10 wt.-%, and most preferably 0 to about 5 wt.-%, based on the total mixture of the components of the reactive adhesive film of the present application. Examples of the further additives and / or auxiliaries include fillers, dyes, nucleating agents, rheological additives (e.g. fumed silica), expanding agents, adhesion promoting additives (adhesion promoters, especially silanes and adhesion promoter resins), compounding agents, plasticizers and / or aging inhibitors, light stabilizers and UV protectants, e.g. in the form of primary and secondary antioxidants. The further components of the reactive adhesive film of the present application can also be reactive monomers at the same time. This can be the case, especially preferably in the case of silane adhesion promoters. Mentioned here can be, for example, 3-trimethoxysilylpropyl methacrylate (CAS No.: 2530-85-0) under the trade name MEMO (Evonik AG, Essen, Germany) is available.

[0063] Reactive adhesive film

[0064] The photocured reactive pressure-sensitive adhesive film of the present application is present in the form of a film. As used herein, the term "adhesive film" (or film of adhesive, layer of adhesive, foil of adhesive) is intended to encompass the complete or incomplete provision of the application of the photocured reactive adhesive mixture as described herein below. For example, the application of the adhesive in the form of dots which do not completely cover the surface of the substrates to be bonded can likewise result in permanent bonding in the sense of the present application.

[0065] In a preferred embodiment, the photocured reactive pressure sensitive adhesive film of the present application comprises: (a) 10 to 80 weight percent of at least one reactive monomer or reactive resin, (b) 0.1 to 10.0 weight percent of an initiator, (c) up to 1.0 weight percent of a photo-redox catalyst, (d) 1.0 to 50.0 weight percent of a polymer obtained by free radical polymerization of carbon-carbon double bond containing monomers, characterized in that these monomers include N-vinyl compounds, and (e) 10 to 90 weight percent of a film forming polymer, and optionally (f) 0 to about 15 weight percent of additional additives and / or adjuvants. Still more preferably: (a) 20 to 60 weight percent of at least one reactive monomer or reactive resin, (b) 0.2 to 4.0 weight percent of an initiator, (c) up to 0.5 weight percent of a photo-redox catalyst, (d) 5.0 to 30.0 weight percent of a polymer obtained by free radical polymerization of carbon-carbon double bond containing monomers, characterized in that these monomers include N-vinyl compounds, and (e) 20 to 60 weight percent of a film forming polymer, and optionally (f) 0 to about 10 weight percent of additional additives and / or adjuvants. Most preferably: (a) about 39 weight percent of at least one reactive monomer or reactive resin, (b) 1.3 weight percent of an initiator, (c) about 0.03 weight percent of a photo-redox catalyst, (d) about 15 weight percent of a polymer obtained by free radical polymerization of carbon-carbon double bond containing monomers, characterized in that these monomers include N-vinyl compounds, and (e) about 41 weight percent of a film forming polymer, and (f) about 4 weight percent of additives.

[0066] In a particularly preferred embodiment, the photocured reactive pressure sensitive adhesive film of the present application comprises a mixture of the following ingredients: a thermoplastic polyurethane, in particular S-6558-06or 530, poly(N-vinylcaprolactam) or poly(N-vinylpyrrolidone), 2-hydroxy-3-phenoxypropyl acrylate or 2-[[(butylamino)carbonyl]oxy]ethyl acrylate, a rheological additive, in particular fumed silica, diisopropyl hydroperoxide and tris(2,2'-bipyridyl)ruthenium(II) chloride hexahydrate.

[0067] A particularly preferred embodiment comprises about 35-45 wt.-% film- forming polymer, 10-20 wt.-% poly(N-vinylcaprolactam) or poly(N-vinylpyrrolidone), 30-50 wt.-% 2-hydroxy-3-phenoxypropyl acrylate or 2-[[(butylamino)carbonyl]oxy]ethyl acrylate, 2-5 wt.-% rheological additive, 0.5-2.0 wt.-% diisopropyl hy- droperoxide and 0.01-0.1 wt.-% tris(2,2'-bipyridyl)ruthenium(II) chloride hexahydrate, based on the total mixture of the components of the reactive adhesive film of the present invention.

[0068] The total mixture of the components of the reactive adhesive film of the present invention as used herein represents the total amount of (a) reactive monomers / reactive resins, (b) initiators, (c) photoredox catalysts, (d) polymers comprising monomers of N-vinyl compounds, (e) film-forming polymers, and optionally further optional components used, which is obtained as a sum in weight percent (wt.-%). Solvents and / or water are only used for manufacturing and thus are not considered part of the total mixture of the components of the reactive adhesive of the present invention. The same applies to solvents already contained in commercially available raw materials.

[0069] The reactive adhesive film of the present invention preferably has a layer thickness in the range of about 20-200 pm, preferably about 30-100 pm, more preferably about 40 to 60 pm and very preferably about 50 pm (measured using a standard commercial thickness measuring instrument, e.g. DM 2000 from Wolf Messtechnik GmbH). In order to produce greater layer thicknesses, it can be advantageous to layer multiple adhesive film layers on top of one another.

[0070] The reactive adhesive film of the present invention is further characterized in that, prior to photocuring, it has pressure-sensitive adhesive properties. According to ( Pressure-sensitive adhesive compounds according to the definition of the Pressure-Sensitive Adhesive Council (PSAC) (Online 2013, document code RD-08-00162) are those viscoelastic adhesive films which set a dry film that is permanently tacky and remains adhesive at room temperature. Pressure-sensitive adhesion is achieved by gentle application of pressure on almost all substrates. Here, gentle application of pressure means an applied pressure of more than 0 bar for a time of more than 0 seconds.

[0071] The photocured reactive pressure-sensitive adhesive film of the present invention can additionally comprise further films, foils, layers, carriers, adhesive films, pressure- sensitive adhesive films, release papers and / or release liners.

[0072] Suitable carrier materials are known to the person skilled in the art. As permanent carriers, for example, foils (polyester, PET, PE, PP, BOPP, PVC, polyimide), nonwovens, foams, woven fabrics and / or woven fabric foils can be used. Temporary carriers should be provided with a release layer, which in this case usually consists of a silicone release varnish or a fluorinated release varnish or is polyolefinic in nature (HDPE, LDPE).

[0073] In a preferred embodiment of the application, the reactive adhesive film (A1 ) of the application together with the further reactive adhesive film (A2) of the application and the film, foil, layer or carrier (B) forms a reactive pressure-sensitive adhesive tape. The reactive pressure-sensitive adhesive tape of the application comprises the layers (A1 ), (A2) and (B) and is characterized in that it comprises the photocured reactive pressure-sensitive adhesive film (A1 ) according to the application and the further photocured reactive pressure-sensitive adhesive film (A2) according to the application and the film, foil, layer or carrier (B) which is arranged flat between the two reactive pressure-sensitive adhesive films. The tape can comprise further layers, for example the photocured reactive pressure-sensitive adhesive film of the application or other adhesive layers or further carrier layers. The film, foil, layer or carrier (B) is preferably a polyethylene, polypropylene or polyester foil, very particularly preferably a polyester foil etched with trichloroacetic acid.

[0074] In a particularly preferred embodiment of the tape, the film, foil, layer or carrier (B) is arranged flat between the two reactive pressure-sensitive adhesive films (A1 ) and (A2), resulting in a three-layer reactive pressure-sensitive adhesive tape arranged in layers (A1 / B / A2). The reactive pressure-sensitive adhesive tape (A1 / B / A2) is characterized in that it comprises the photocured reactive pressure-sensitive adhesive film (A1 ) according to the application and the further photocured reactive pressure-sensitive adhesive film (A2) according to the application and the film, foil, layer or carrier (B) which is arranged flat between the two reactive pressure-sensitive adhesive films (A1 ) and (A2). In a more preferred embodiment of the application, the film, foil, layer or carrier (B) arranged between the two reactive pressure-sensitive adhesive films (A1 ) and (A2) of the application is a polyethylene, polypropylene or polyester foil, very preferably a polyester foil etched with trichloroacetic acid. Such an etched polyester foil with a thickness of 12 pm is available, for example, under the trade name HPH 100 12pm (from Coveme S.P.A, San Lazzaro di Savena, Italy).

[0075] Method for producing a reactive adhesive film

[0076] The manufacture of the photocured reactive pressure-sensitive adhesive adhesive film of the present invention is carried out at the latest after the addition of a photoredox catalyst under exclusion of UV light or visible light, in particular violet and blue light, of a wavelength that excites the respective photoredox catalyst. Typically, these are wavelengths of less than 500 nm. The exclusion can typically be achieved using standard commercial yellow light lamps and by masking the usual light sources having a UV portion and / or violet and blue light portion in their wavelength spectrum by using standard commercial UV-protective yellow light foils.

[0077] The reactive adhesive film of the present invention is woven by the following method:

[0078] In a first step, the ingredients are dissolved or finely dispersed in one or more solvents and / or water. Suitable solvents are known in the prior art and the solvents used are preferably those in which at least one of the ingredients has good solubility. Acetone and methyl ethyl ketone (MEK) are particularly preferred.

[0079] As used herein, the term "ingredients" includes (a) at least one reactive monomer / reactive resin as defined above, (b) an initiator, (c) a photoredox catalyst, (d) a polymer obtained by radical polymerization of monomers containing carbon-carbon double bonds, characterized in that these monomers include N-vinyl compounds, (e) a film-forming polymer, and optionally further optional ingredients.

[0080] The dissolved or finely dispersed ingredients are then mixed in a second step using customary stirring devices. At the same time, the ingredients are optionally dissolved, finely dispersed and mixed.

[0081] Subsequently, in a third step, a film, foil, layer, carrier, adhesive film, pressure-sensitive adhesive film, preferably a release liner or release paper, is coated with the mixture of dissolved, finely dispersed ingredients. The coating is carried out according to the usual techniques known in the prior art.

[0082] After the coating has been carried out, the solvent is removed by evaporation in a fourth step. This is preferably carried out in the temperature range from 60 to 80°C, depending on the solvent used.

[0083] Optionally, the reactive adhesive film can be wound into a roll in a further step.

[0084] For storage, the reactive adhesive film of the present invention is lined with a release liner or release paper.

[0085] The three-layer reactive pressure-sensitive adhesive tape of the present application is manufactured by manufacturing the first (A1 ) and second (A2) reactive pressure-sensitive adhesive films of the present application, contacting the two reactive pressure-sensitive adhesive films of the present application with a film, foil, layer or carrier (B), in a lamination operation or by direct coating, to obtain a three-layer reactive pressure-sensitive adhesive tape arranged in layers (A1 / B / A2).

[0086] Substrate

[0087] Suitable substrates for bonding with the reactive adhesive films according to the present application are various plastics, metals, glasses and / or ceramics. The substrates to be bonded can be identical or different. They can be transparent or non-transparent.

[0088] The reactive adhesive films of the present application are preferably used for the bonding of plastics, metals and glasses. More preferably bonded are polycarbonates, polyamides, anodized aluminum, steel (e.g. stainless steel) and glass (in particular surface treated glass).

[0089] The metal substrates to be bonded can generally be made of all conventional metals and metal alloys. Preference is given to using metals such as aluminum, stainless steel, steel, magnesium, zinc, nickel, brass, copper, titanium, ferrous metals and alloys. The parts to be bonded can additionally be composed of different metals.

[0090] Suitable plastic substrates are, for example, polycarbonates (PC), polyamides (PA), acrylonitrile-butadiene-styrene copolymers (ABS), ABS / PC blends, PMMA, glass fiber reinforced polyamides, polyvinyl chloride, polyvinylidene chloride, cellulose acetate, cyclic olefin copolymers, liquid crystal polymers (LCP), polylactide, polyether ketone, polyether imide, polyether sulfone, polymethacrylomethylimide, polymethylpentene, polyphenylene ether, polyphenylene sulfide, polyphthalamide, polyurethane, polyvinyl acetate, styrene acrylonitrile copolymers, polyacrylate and polymethacrylate, polyformaldehyde, acrylate-styrene-acrylonitrile copolymers, polyethylene, polystyrene, polypropylene and / or polyesters, for example polybutylene terephthalate (PBT) and / or polyethylene terephthalate (PET).

[0091] The substrates can have been printed or coated by surface coating, vapor deposition or sputtering.

[0092] The substrates to be bonded are preferably planar or two-dimensionally curved in terms of their form. However, depending on the degree of curvature, three-dimensionally curved substrates can also be bonded with the reactive adhesive films of the present application. The substrates to be bonded can also assume a variety of different functions, for example as a housing, viewing window, reinforcing element, etc.

[0093] Optionally, a pre-treatment of the surface of the substrates to be adhered by physical, chemical and / or physical-chemical processes can be necessary. For example, the application of a primer or adhesion promoter composition is here advantageous. Corona, plasma or flame pre-treatment can also be advantageous.

[0094] Using the reactive adhesive film of the present application, components in the electronics industry, in particular smartphone and tablet components, such as touch screens, can be advantageously adhered. Preferred adhesions are the fixation of camera lenses, the adhesion of flexible displays in "wearable devices", such as fitness trackers and smartwatches, the fixation / assembly of antenna or back lighting units in smartphones or tablets, the film lamination and assembly of FPCs (flexible printed circuits) or loudspeaker drivers.

[0095] Adhesion process

[0096] The reactive adhesive film of the present application can be used in a process for adhering two substrates, such as substrate 1 (e.g. polycarbonate) and a further substrate 2 (e.g. metal) to obtain a composite element. The process for adhering two substrates of the present application comprises the following steps: (i) providing a first substrate and a second substrate; (ii) arranging the reactive adhesive film of the present application or the reactive pressure sensitive adhesive tape of the present application on substrate 1 ; (iii) irradiating the adhesive film or tape with UV light or blue light before or after arranging the adhesive film or tape on substrate 1 to form an irradiated adhesive film or irradiated adhesive tape and to cause curing; (iv) arranging the two substrates so that they are joined to each other by the irradiated adhesive film or irradiated adhesive tape; and (v) curing the irradiated adhesive film or irradiated adhesive tape as a result of the irradiation after arranging. Alternatively to this, the irradiation of step (iii) can also be carried out after the arranging or joining (iv) of the two substrates.

[0097] Composite element

[0098] Also provided in the present application is a composite element comprising at least two adhering surfaces, wherein the two adhering surfaces are joined by the cured reactive adhesive film of the present application or by the cured reactive pressure sensitive adhesive tape, as defined above.

[0099] Product properties

[0100] The reactive adhesive film of the present application shows superior product properties, as even the skilled person cannot foresee. Depending on the used photo-oxidation- reduction catalyst, the adhesive film can be cured using standard commercial UV-LED lamps or blue light LED lamps (e.g. 365 nm, 385 nm, 395 nm, 405 nm, 450 nm and 460 nm wavelength). Surprisingly, it was found that in many cases, the UV-LED lamps or blue light LED lamps are equally suitable. Standard commercial mercury vapor UV lamps can also be suitable.

[0101] Examples of suitable LED light sources for curing the reactive adhesive film of the present invention include the following products from (Dr AG, Gilching, Germany, https: / / www.hoenle.de / ) :

[0102] a) LED Spot 100HP IC 365 nm (UV-LED)

[0103] b) LED Spot 100HP IC 460 nm (blue light LED)

[0104] The irradiation chamber tailored to these light sources is the LED Cube 100 IC, again from AG, Gilching, Germany. Suitable doses are in the range of about 10 to 80 J / cm 2 . For this, typically a power level of 30% to 90% is chosen on the equipment described. The chosen irradiation time is between 10 and 60 seconds. The distance between the light source and the reactive adhesive film of the present invention is about 2 to 10 cm. When using other equipment with different power, considerable deviations from the values described are to be expected.

[0105] After the irradiation has taken place, the adhesive film does not cure immediately. Initially, it remains pressure-sensitive adhesive. Depending on the photoredox catalyst used and the exact adhesive formulation, the substrates can be bonded or joined over a period of at least five minutes, in some cases even up to 30 minutes. In other words: the adhesive film of the present invention has an open time of at least five minutes after the initiation of the irradiation and thus the curing. The adhesive film of the present invention cures completely over a period of about 24 hours after the end of the irradiation. The curing takes place independently of (not dependent on) light and thus even in the dark. Thus, using the adhesive film / adhesive film of the present invention, even non-transparent substrates can be bonded.

[0106] Using the reactive adhesive film of the present invention, high adhesive strengths are achieved. In push-out tests, values of more than 8 MPa can be achieved in the bonding of polycarbonate test specimens (see examples). The bonding of steel and anodized aluminum also results in similarly high bond strengths. Even polyamide, which is generally considered a difficult-to-bond substrate, can be bonded well with the reactive adhesive film of the present invention, even without pretreatment. In push-out tests, adhesive strengths of more than 5 MPa can be achieved (see examples). This order of magnitude is referred to in general parlance as "structural (structural bonding)".

[0107] Surprisingly, it has been found that adhesion using the reactive adhesive film of the present application is characterized by high resistance to combined heat and humidity. The push-off strength of the cured adhesive joint after storage of the adhered substrates at 60°C and 95% relative humidity for 3 days typically reaches at least 70% of the value before the hygrothermal storage. In fact, the strength achieved after the hygrothermal storage is often higher than those before the hygrothermal storage.

[0108] Experimental Part

[0109] The following examples serve to illustrate the present application but are by no means to be interpreted as limiting the scope of protection.

[0110] Table 1 lists the starting compounds and materials used for the manufacture of the photocured pressure-sensitive adhesively reactive adhesive films, the three-layer photocured pressure-sensitive adhesively reactive adhesive tapes of the present application and the comparative examples, including in each case the trade name, an indication of the manufacturer or source of purchase, and technical data relevant to the present application.

[0111]

[0112]

[0113] Table 1 : Starting compounds and materials used for the manufacture of the photocured pressure-sensitive adhesively reactive adhesive films, the three-layer photocured pressure-sensitive adhesively reactive adhesive tapes of the present application and the comparative examples

[0114] Further used was a standard commercial siliconized release liner (release foil). The solvents used in the examples and comparative examples of the present application were acetone (CAS No.: 67-64-1), methyl ethyl ketone (CAS No.: 78-93-3), isopropyl alcohol (CAS No.: 67-63-0) and fully demineralized water.

[0115] Manufacture of a solution of the film polymer

[0116] For practical reasons, a solution of the film polymer was first manufactured.

[0117] Polyurethane (PU) solution:

[0118] A 20% solution of the film polymer was manufactured by first dissolving 120 g S-6558-06 or 120 g 530 together with 240 g acetone and 240 g methyl ethyl ketone into a screw top jar, which was then closed. The polyurethane was completely dissolved by rolling the screw top jar on a commercial roller table for several days. Depending on the rolling speed, the process lasted about one to seven days. Alternatively, the solution can also be manufactured by stirring the polyurethane pellets in a mixture of acetone and methyl ethyl ketone using a commercial laboratory stirrer.

[0119] Manufacture of film acrylate copolymer solution

[0120] (Copolymer name: AC-1, copolymer solution name: AC-1 solution)

[0121] A 10 L glass reactor, which is conventionally used for radical polymerization, was charged with 3.48 kg of n-butyl acrylate, 0.4 kg of ethyl acrylate, 0.12 kg of acrylic acid, 3.84 kg of acetone, and 0.16 kg of isopropyl alcohol. With stirring (70 rpm) and nitrogen passing, the reactor was heated to a jacket temperature of 65°C. When the internal temperature reached 58°C, 2.0 g of azobisisobutyronitrile was added. 67. After further stirring for one hour at a jacket temperature of 65°C, 2.0 g of azobisisobutyronitrile was added again. 67. After further stirring for 6 hours at a jacket temperature of 65°C, the speed of the stirrer was reduced to 35 rpm. The reaction time was 20 hours. Thereafter, the solution was cooled to room temperature and diluted with acetone to a solid content of 40.0% by weight. The molar mass of the obtained copolymer was determined by thermal field flow fractionation. The results were:

[0122] Mn = 155 000 g / mol, Mw = 183 000 g / mol.

[0123] Manufacture of polymer from monomers including N-vinyl compounds

[0124] In the case of poly(N-vinylpyrrolidone), the examples use a commercial, powdered product K30P.

[0125] Other polymers are manufactured from commercially available monomers by radical polymerization. For the manufacture of the reactive adhesive film of the present invention, in these cases the polymer solution manufactured is used without prior removal of the solvent.

[0126] Poly(N-vinylcaprolactam) solution:

[0127] A 10 L glass reactor, which is conventionally used for radical polymerization, was charged with 4.0 kg of N-vinylcaprolactam, 3.84 kg of acetone, and 0.16 kg of isopropyl alcohol. With stirring (70 rpm) and nitrogen passing, the reactor was heated to a jacket temperature of 65°C. When the internal temperature reached 58°C, 2.0 g of azobisisobutyronitrile was added. 67. After further stirring for one hour at a jacket temperature of 65°C, 2.0 g of azobisisobutyronitrile was added again. 67. After further stirring for 6 hours at a jacket temperature of 65°C, the speed of the stirrer was reduced to 35 rpm. The reaction time was 20 hours. Thereafter, the solution was cooled to room temperature and diluted with acetone to a solid content of 40.0% by weight. The molar mass of the obtained poly(N-vinylcaprolactam) was determined by thermal field flow fractionation. The results were:

[0128] Mn = 74 000 g / mol, Mw = 116 500 g / mol.

[0129] Poly(N-vinylcaprolactam / butyl acrylate) (50 / 50) solution:

[0130] A 10 L glass reactor, which is conventionally used for radical polymerization, was charged with 2.0 kg N-vinylcaprolactam, 2.0 kg butyl acrylate, 3.84 kg acetone and 0.16 kg isopropanol. With stirring (70 rpm) and nitrogen passage, the reactor was heated to a jacket temperature of 65 °C. When the internal temperature reached 58 °C, 2.0 g 67. After a further one hour of stirring at a jacket temperature of 65 °C, a further 2.0 g 67. After a further 6 hours of stirring at a jacket temperature of 65 °C, the stirrer speed was reduced to 35 rpm. The reaction time was 20 hours. Thereafter, the solution was cooled to room temperature and diluted with acetone to a solid content of 40.0 wt.-%. The molar masses of the resulting N-vinylcaprolactam / butyl acrylate copolymer were determined by thermal field flow fractionation. The results:

[0131] Mn = 83 000 g / mol, Mw = 124 000 g / mol.

[0132] Poly(N-vinylcaprolactam / butyl acrylate) (80 / 20) solution:

[0133] A 10 L glass reactor, which is conventionally used for radical polymerization, was charged with 3.2 kg N-vinylcaprolactam, 0.8 kg butyl acrylate, 3.84 kg acetone and 0.16 kg isopropanol. With stirring (70 rpm) and nitrogen passage, the reactor was heated to a jacket temperature of 65 °C. When the internal temperature reached 58 °C, 2.0 g 67. After a further one hour of stirring at a jacket temperature of 65 °C, a further 2.0 g 67. After a further 6 hours of stirring at a jacket temperature of 65 °C, the stirrer speed was reduced to 35 rpm. The reaction time was 20 hours. Thereafter, the solution was cooled to room temperature and diluted with acetone to a solid content of 40.0 wt.-%. The molar masses of the resulting N-vinylcaprolactam / butyl acrylate copolymer were determined by thermal field flow fractionation. The results:

[0134] Mn = 78 000 g / mol, Mw = 120 500 g / mol.

[0135] Manufacture of an aqueous solution of a photo-oxidation-reduction catalyst

[0136] First, a 5 wt.-% aqueous solution of the photo-oxidation-reduction catalyst is produced.

[0137] tris(2,2'-bipyridyl) ruthenium(II) chloride hexahydrate aqueous solution

[0138] In yellow light, 5 g of tris(2,2'-bipyridyl) ruthenium(II) chloride hexahydrate and 95 g of completely demineralized water are weighed into a brown screw jar. The jar is closed. The jar is rolled on a roller table for 8 hours to completely dissolve the tris(2,2'-bipyridyl) ruthenium(II) chloride hexahydrate.

[0139] Example 1

[0140] Production of the inventive reactive adhesive film and the inventive three-layer reactive adhesive tape

[0141] In a brown screw jar, 70.66 g 530 20 wt.-% solution in acetone / methyl ethyl ketone (PU solution), 13.25 g 40 wt.-% poly(N-vinylcaprolactam) solution, 13.66 g 2-hydroxy-3-phenoxypropyl acrylate and 1.34 g R202, and mixed with a commercial laboratory stirrer at medium speed (500-1000 rpm) for 15 minutes. Then, 0.88 g IHP-50 (containing 50 wt.-% diisopropyl hydroperoxide) is added. Mixing is performed at medium speed for 5 minutes.

[0142] All further operations are performed under yellow light. The selected overhead yellow light illumination is a LT35 WT5 EQ / Yellow Special fluorescent lamp from NARVA Lichtquellen GmbH (NARVA Lichtquellen GmbH + Co. KG, Brand-Erbisdorf, Germany, www.narva-bel.de), which blocks wavelengths smaller than 500 nm. To mask the remaining residual light from other light sources, a Metolight SFLY-5 yellow foil (ASMETEC GmbH, Kirchheimbolanden, Germany, www.asmetec.de) is chosen, which filters out wavelengths smaller than 470 nm. 0.21 g of a 5 wt.-% tris(2,2'-bipyridyl) ruthenium(II) chloride hexahydrate aqueous solution is added, and mixed with a laboratory stirrer at medium speed for 5 minutes. Subsequently, the mixture is further mixed on a commercial roller table for 24 hours.

[0143] The obtained homogeneous mixture was coated successively 3 times with a coating knife by means of a commercial laboratory coating table (e.g. from SMO, Sondermaschinen Oschersleben GmbH, Oschersleben, Germany) onto siliconized polyester foil (release liner) to obtain 3 films. Subsequently the solvent was evaporated in a forced air drying oven at 60°C for 15 minutes. The slit width during coating was varied. It was set twice so that the films obtained after solvent evaporation were 50 μιη thick. In the third coating experiment the slit width was set so that the film obtained after solvent evaporation was 100 μιη thick. The obtained 100 μιη thick photocured reactive pressure sensitive adhesive film was lined with a second layer of siliconized polyester foil (release liner). Then, circular die cuts (test pieces) with a diameter of 21 mm were punched out of the product and stored in light tight plastic jars before testing. Testing was performed two weeks after die cut manufacture and after six months of storage of the die cuts at 23°C and 50% relative humidity.

[0144] To manufacture the three-layered reactive adhesive tape of the present invention, the first of the two 50 μιη thick reactive adhesive films was laminated onto a trichloroacetic acid etched polyester foil HPH 100 12μ onto the second side of the trichloroacetic acid etched polyester foil. The obtained three-layered photocured reactive pressure sensitive adhesive tape was lined on both sides with the respective siliconized polyester foil (release liner). After that, annular die cuts with an outer diameter of 18 mm and an inner diameter of 13 mm were punched out of the product. These die cuts were also stored in light tight plastic jars before testing. Here again, testing was performed two weeks after die cut manufacture and after six months of storage of the die cuts at 23°C and 50% relative humidity.

[0145] The percent composition of the initial weightings of the solutions / mixtures used to manufacture the photocured reactive pressure sensitive adhesive films, as well as the percent composition of the photocured reactive pressure sensitive adhesive films themselves, are listed in the two tables below.

[0146] Example 1 : Percent composition of the solutions / mixtures used to prepare the reactive adhesive films

[0147] Example 1 : Percent composition of the solutions / mixtures used to prepare the reactive adhesive films

[0148]

[0149] The reactive adhesive film of the present invention and the three-layer reactive adhesive tape of the present invention were manufactured in a similar manner to Example 1 in additional inventive examples and comparative examples.

[0150] The following table provides information on the percent composition of the solutions / mixtures used to manufacture the reactive adhesive films and the percent composition of the solvent-free reactive adhesive films in additional inventive examples and comparative examples.

[0151] Example 2: Percent composition of solutions / mixtures used to prepare the reactive adhesive films

[0152]

[0153] Example 2: Percent composition of solutions / mixtures used to prepare the reactive adhesive films

[0154]

[0155] Example 3: Percent composition of solutions / mixtures used to prepare the reactive adhesive films

[0156]

[0157] Example 3: Percent composition of solutions / mixtures used to prepare the reactive adhesive films

[0158]

[0159] Example 4: Percent composition of solutions / mixtures used to prepare the reactive adhesive films

[0160]

[0161] Example 4: Percent composition of solutions / mixtures used to prepare the reactive adhesive films

[0162]

[0163]

[0164] Example 5: Percent composition of solutions / mixtures used to prepare the reactive adhesive films

[0165]

[0166] Example 5: Percent composition of solutions / mixtures used to prepare the reactive adhesive films

[0167]

[0168] Example 6: Percent composition of solutions / mixtures used to prepare the reactive adhesive films

[0169]

[0170]

[0171] Example 6: Percent composition of solution / mixture used to make reactive adhesive film

[0172]

[0173] Example 7: Percent composition of solution / mixture used to make reactive adhesive film

[0174]

[0175] Example 7: Percent composition of reactive adhesive film

[0176]

[0177]

[0178] Example 8: Percent composition of solution / mixture used to make reactive adhesive film

[0179]

[0180] Example 8: Percent composition of reactive adhesive film

[0181]

[0182] Example 9: Percent composition of solution / mixture used to make reactive adhesive film

[0183]

[0184]

[0185] Example 9: Percent composition of reactive adhesive film

[0186]

[0187] Example 10: Percent composition of solution / mixture used to make reactive adhesive film

[0188]

[0189] Example 10: Percent composition of reactive adhesive film

[0190]

[0191]

[0192] Example 11: Percent composition of solution / mixture used to make reactive adhesive film

[0193]

[0194] Example 11, Percent Composition of Reactive Adhesive Film

[0195]

[0196] Comparative Example

[0197] Comparative Example 1, Percent Composition of Solution / Mixture

[0198]

[0199] Comparative Example 1, Percent Composition of Film

[0200]

[0201] Comparative Example 2, Percent Composition of Solution / Mixture

[0202]

[0203] Comparative Example 2, Percent Composition of Film

[0204]

[0205] Comparative Example 3, Percent Composition of Solution / Mixture

[0206]

[0207] Comparative Example 3, Percent Composition of Film

[0208]

[0209]

[0210] Comparative Example 4, Percent Composition of Solution / Mixture

[0211]

[0212] Comparative Example 4, Percent Composition of Film

[0213]

[0214] Push-Off Test

[0215] The push-off test provides information about the adhesive strength of an adhesive product with double-sided adhesion in the direction of the adhesive layer normal.

[0216] Test Specimen for Push-Off Test

[0217] A circular plate (coupon) with a diameter of 21 mm was used.

[0218] Further used was a square perforated plate with a side length of 40 mm. The perforation was in the center in each case. It was circular and in each case the perforation diameter was 9 mm. The test pieces used were made of polycarbonate and SUS steel. The square perforated plates used were made of polycarbonate, polyamide, anodized aluminum and SUS steel.

[0219] The following specific test specimens were used:

[0220] a) Test pieces:

[0221] - plastic disc of polycarbonate (PC) Makrolon 099, ground to remove flash, 21 x 3 mm

[0222] - steel disc, steel grade VA 1.4301 (corresponds to SUS 304), outer contour laser cut, mirror polished on one side, 21 x 2 mm

[0223] b) Square perforated plate:

[0224] - plastic specimen of polycarbonate (PC), product Makroform 099, 40 x 40 x 4 mm, hole in the center in the plastic, D = 9 mm

[0225] - plastic specimen of polyamide (PA), glass fiber reinforced, product PA6 granulate natural, 25% GF, Ultramid B3 WG5, 40 x 40 x 4 mm, hole in the center in the plastic, D = 9 mm

[0226] - specimen of aluminum (Al), alloy 5005 A, AlMg1, anodized E6 EV1, 40 x 40 x 2 mm, hole in the center in the aluminum, D = 9 mm

[0227] - specimen of steel, steel grade VA 1.4301 (corresponds to SUS 304), inner and outer contour laser cut, surface mirror polished, 40 x 40 x 3 mm, hole in the center in the steel, D = 9 mm

[0228] The plastic and aluminum test specimens were obtained from Rocholl GmbH (Eschelbronn, Germany, https: / / rocholl.eu / ). The supplier of the steel test specimens was Classen GmbH (Rellingen, Germany, www.classen-laser.de / ).

[0229] Sample preparation for push-out test

[0230] A single layer of photocured reactive pressure-sensitive adhesive adhesive film (in the form of a round die-cut (test patch), 100 pm thick) of the present invention and a three-layer reactive adhesive tape of the present invention (which consists of two 50 pm thick reactive films and a 12 pm thick trichloroacetic acid-etched polyester foil arranged in the middle between the two 50 pm thick reactive films, and in the form of a punched ring) were distinguished.

[0231] In each case, the die-cut release liner was removed from one side of the die-cut.

[0232] The die-cuts were each placed in the middle at the center of the test specimen patch.

[0233] The die-cuts were then adhered to the test specimen patch.

[0234] Thereafter, the release paper still remaining on the die-cuts was removed. The test specimen patch was thus now equipped with a single layer of reactive adhesive film (patch) and a three-layer reactive adhesive tape (ring).

[0235] Irradiation for push-out test

[0236] Irradiation was carried out in a first series of experiments with exclusively UV-LED light (365 nm) and in a second series of experiments with exclusively blue light LEDs (460 nm).

[0237] The dose was selected as follows:

[0238] - LED Spot 100HP IC 365 nm (UV-LED): 25.0 - 28.0 J / cm 2

[0239] - LED Spot 100HP IC 460 nm (blue light LED): 50.0 - 55.0 J / cm 2

[0240] The dose of the UV-LED light was measured using an EIT UV Power Puck II (UV-A) from UVECO (Bruckmühl, Germany, www.uveco.de). The dose of the blue light LED was measured with a UV meter and a surface sensor VIS Fl (360-550 nm) from

[0241] The time span between the end of the irradiation and the joining of the test specimen was always between one and two minutes. Several checks were carried out and it was determined that a time difference of at least 5 minutes or more was also possible without a deterioration in the adhesive strength.

[0242] Adhesion for push-out test

[0243] ​The test specimen coupon equipped with the irradiated diecut was placed on the perforated plate with the respective exposed side of the diecut so that the center point of the coupon and the center point of the perforation of the perforated plate overlapped each other. The assembly consisting of the square perforated plate, the irradiated diecut and the test specimen coupon was then pressed using a press from Howe Elektrotechnik e.K. (Glinde, Germany, https: / / howe-hamburg.de / ). The pressing parameters were as follows: 3 bar, 30 seconds.

[0244] After the pressing operation, the assembly was stored for 24 hours at 23 °C and 50% relative humidity (r.h.). During this time, the curing reaction within the diecut proceeds gradually and the adhesion between the diecut and the test specimen increases gradually. Thus, there is an adhesion which increases in strength over time. Then the push-out test was performed (fresh value).

[0245] Furthermore, after a 24 hours curing time, the respective adhesive assembly was stored for 3 days (d) in a commercial conditioning chamber at 60 °C and 95% relative humidity. Subsequently, the adhesive assembly was stored (rejuvenation) for 1 hour at 23 °C and 50% relative humidity. Then the push-out test was performed to assess the humidity resistance of the adhesion.

[0246] To assess the storage stability, an unirradiated and unadhered diecut lined with release liner on both sides was stored in the dark at 23 °C and 50% relative humidity for six months. Then the diecut was irradiated and adhered as described above. Then the push-out test was performed.

[0247] Another unirradiated and unadhered diecut lined with release liner on both sides was also irradiated and adhered as described above after six months storage in the dark at 23 °C and 50% relative humidity. After a 24 hours curing time, the adhesive assembly was stored for 3 days in a commercial conditioning chamber at 60 °C and 95% relative humidity. Subsequently, the adhesive assembly was stored (rejuvenation) for 1 hour at 23 °C and 50% relative humidity. Then the push-out test was performed to assess the humidity resistance of the adhesion of the diecut for six months.

[0248] In summary, the following combinations of storage and hydrothermal treatment were implemented:

[0249]

[0250] The test specimens were adhered in the following combinations:

[0251] • PC coupon to PC plate

[0252] • PC coupon to PA plate

[0253] • PC coupon to Al plate

[0254] • Steel coupons to steel sheet

[0255] The bonding area was as follows:

[0256] - Round die cut (coupon): 283 mm 2 (considering the 9 mm perforation in the sheet)

[0257] - Ring die cut: 122 mm 2

[0258] Procedure for push-out test

[0259] The test coupon was subjected to a constant rate of 10 mm / min vertical pressure (i.e. parallel to the normal vector on the plane of the test coupon; centrally on the middle of the perforation) by means of a mandrel clamped in a tensile testing machine through the perforation in the sheet until the adhesive had separated to the extent that a 50% pressure drop was recorded. The pressure acting just before the pressure drop was the maximum pressure P 最大 . This value corresponds to the push-out value [MPa] reported in the table. All measurements were carried out in a temperature-controlled room at 23 °C and 50% relative humidity (r.h.).

[0260] Push-out results

[0261] For all inventive examples:

[0262] In each case, the average value and standard deviation from 3 separate determinations.

[0263] Fracture mode:

[0264] A = Adhesive

[0265] K = Cohesive

[0266] M = Mixed fracture

[0267] Example 1

[0268]

[0269]

[0270] Example 2

[0271]

[0272]

[0273] Example 3

[0274]

[0275]

[0276] Example 4

[0277]

[0278]

[0279] Example 5

[0280]

[0281]

[0282] Example 6

[0283]

[0284]

[0285] Example 7

[0286]

[0287]

[0288]

[0289] Example 8

[0290]

[0291]

[0292] Example 9

[0293]

[0294]

[0295] Example 10

[0296]

[0297]

[0298] Example 11

[0299]

[0300]

[0301]

[0302] Comparative Example

[0303] For all Comparative Examples:

[0304] In each case, the average value and standard deviation from 3 separate determinations.

[0305] Mode of fracture:

[0306] A = adhesive

[0307] K = cohesive

[0308] M = mixed mode

[0309] Comparative Example 1

[0310]

[0311]

[0312] Comparative Example 2

[0313]

[0314]

[0315] Comparative Example 3

[0316]

[0317]

[0318] Comparative Example 4

[0319]

[0320]

[0321] Discussion of results

[0322] The reactive adhesive film of the present invention can be cured with both UV-LED light and blue LED light. After irradiation, the film does not cure completely immediately, but has an open time of at least 5 minutes. It continues to cure in the dark and is thus suitable for bonding of opaque substrates. It constitutes a significant improvement over the prior art in that the bonding using the adhesive film is notable for high adhesive strength and high resistance to heat and moisture for the combination. This is demonstrated for the bonding of polycarbonate (PC), polyamide (PA), aluminum and SUS steel. The preferred embodiments lead to higher adhesive strength and / or more uniform results on a variety of substrates and also to better storage stability.

[0323] The comparative examples of polymers not comprising monomers of N-vinyl compounds show that the adhesive assembly is not sufficiently resistant to heat and humidity of the combination. Especially after long time storage of the die cut, the replacement of the polymer by the monomer N-vinyl caprolactam leads to an insufficient resistance of the adhesive assembly to heat and humidity of the combination and generally to an insufficient storage stability of the die cut.

Claims

1. Photocured, reactive, pressure-sensitive adhesive film, comprising (a) at least one reactive monomer or reactive resin, (b) initiator, (c) photoredox catalyst, (d) polymer obtained by radical polymerization of monomers containing carbon-carbon double bonds, characterized in that these monomers comprise N-vinyl compounds, and (e) film-forming polymer, wherein at least 50% by weight of the monomers of polymer (d) are N-vinyl compounds, and wherein the fraction of polymer (d) is in the range of 1 to 50% by weight, based on the total mixture of the constituents of the adhesive film. The reactive monomer or reactive resin (a) comprises at least one representative selected from the group consisting of acrylates, methacrylates, vinyl compounds and / or oligomeric or polymeric compounds having carbon-carbon double bonds, and crosslinking reactive monomers. The reactive monomers are diacrylates, dimethacrylates, triacrylates, trimethacrylates, higher functionality acrylates and higher functionality methacrylates. The photoredox catalyst (c) comprises ruthenium as central atom and bipyridine or mono- or polysubstituted bipyridine derivatives as ligand, or iridium as central atom and phenylpyridine or mono- or polysubstituted phenylpyridine derivatives as ligand. The N-vinyl compounds of polymer (d) are compounds corresponding to formula (II) or comprise structural units of formula (II), wherein A is an organic radical R or H, B is an organic radical R or H or OR or OH or NR2 or NHR or NH2, A and B can form a ring. The film-forming polymer (e) comprises a thermoplastic polymer. The film-forming polymer (e) comprises an elastomer.

2. The photocured reactive pressure-sensitive adhesive film according to claim 1, characterized in that, The film-forming polymer (e) comprises a thermoplastic elastomer.

3. The photocured, reactive, pressure-sensitive adhesive film according to claim 2, wherein The film-forming polymer (e) comprises a thermoplastic polyurethane.

4. The photocured reactive pressure-sensitive adhesive film according to claim 2, wherein The reactive monomers are 2-phenoxyethyl acrylate, 2-phenoxyethyl methacrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-hydroxy-3-phenoxypropyl methacrylate, 2-[2-(methacryloyloxy)ethoxycarbonyl]benzoic acid, 2-[[(phenylamino)carbonyl]oxy]ethyl methacrylate, 2-tert-butyl-6-[(3-tert-butyl-2-hydroxy-5-methylphenyl)methyl]-4-methyl-phenyl acrylate, and (5-ethyl-1,3-diethyl)acrylate. Alkyl-5-yl)methyl ester, (2-oxo-1,3-dioxolane-4-yl)methyl methacrylate, di(ethylene glycol) 2-ethylhexyl ether acrylate, (2,2-dimethyl-1,3-dioxolane-4-yl)methyl acrylate, mono-[2-(acryloyloxy)ethyl ester] succinic acid, mono-[2-(methacryloyloxy)ethyl ester] succinic acid, (2,2-pentamethylene-1,3-)methyl methacrylate (3-oxazolidinyl)ethyl ester, 2-hydroxy-3-(prop-2-enoyloxy)propyl 2-methyl-2-propylhexanoate, 2-[[(butylamino)carbonyl]oxy]ethyl acrylate, stearyl acrylate, stearyl methacrylate, and crosslinking reactive monomers dicarboxylate dimethacrylate (mixture of isomers), bisphenol A glycerol dimethacrylate (BIS-GMA), bisphenol A dimethacrylate (BIS-DMA), ethylene glycol diacrylate, ethylene glycol dimethacrylate, trimethylolpropane propoxy triacrylate, trimethylolpropane triacrylate and / or di(trimethylolpropane)tetraacrylate.

5. Photocured, reactive, pressure-sensitive adhesive film according to any of the preceding claims, characterized in that 13. Photocured, reactive, pressure-sensitive adhesive film according to any one of claims 1 to 4, comprising (a) 10 to 80% by weight of at least one reactive monomer or reactive resin, (b) 0.1 to 10.0% by weight of initiator, (c) up to 1.0% by weight of photoredox catalyst, (d) 1.0 to 50.0% by weight of polymer obtained by radical polymerization of monomers containing carbon-carbon double bonds, characterized in that these monomers comprise N-vinyl compounds, (e) 10 to 90% by weight of film-forming polymer.

14. Photocured, reactive, pressure-sensitive adhesive film according to claim 13, comprising (a) 20 to 60% by weight of at least one reactive monomer or reactive resin, (b) 0.2 to 4.0% by weight of initiator, (c) up to 0.5% by weight of photoredox catalyst, (d) 5.0 to 30.0% by weight of polymer obtained by radical polymerization of monomers containing carbon-carbon double bonds, characterized in that these monomers comprise N-vinyl compounds, (e) 20 to 60% by weight of film-forming polymer. ​ ​ 6. The photocured reactive pressure-sensitive adhesive film according to any one of claims 1 to 4, characterized in that, The photo-oxidation reduction catalyst (c) comprises [tris(2,2'-bipyridyl)ruthenium(II)] 2+ , tris[2-(2,4-difluorophenyl)pyridine]iridium(III) or tris(2-phenylpyridyl)iridium(III).

7. The photocured reactive pressure-sensitive adhesive film according to any one of claims 1 to 4, characterized in that, ​ ​ ​ ​ - R is independently and at each occurrence a substituted or unsubstituted branched, cyclic, or straight chain C 1-20 alkyl or C 2-20 alkenyl; or is substituted or unsubstituted aryl or heteroaryl, ​ 8. The photocured reactive pressure-sensitive adhesive film according to any one of claims 1 to 4, characterized in that, The N-vinyl compound of the polymer (d) includes N-vinyl caprolactam or N-vinyl pyrrolidone or 5-methyl-3-vinyl-2- oxazolidone.

9. The photocured reactive pressure-sensitive adhesive film according to any one of claims 1 to 4, characterized in that, ​ 10. The photocured reactive pressure-sensitive adhesive film according to any one of claims 1 to 4, characterized in that, ​ 11. The photocured, reactive, pressure-sensitive adhesive film according to any one of claims 1 to 4, characterized in that, ​ 12. The photocured, reactive, pressure-sensitive adhesive film of claim 9, wherein, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 15. The photocured, reactive, pressure-sensitive adhesive film according to any one of claims 1 to 4, comprising a further film, foil, layer, carrier, release paper and / or release liner.

16. The photocured, reactive, pressure-sensitive adhesive film of claim 15, wherein, The film is an adhesive film.

17. The photocured, reactive, pressure-sensitive adhesive film of claim 15, wherein, The film is a pressure-sensitive adhesive film.

18. The photocured, reactive, pressure-sensitive adhesive film of claims 1 or 2, wherein, The fraction of reactive monomers and / or reactive resins is in the range of 10 to 80 wt.%, based on the total mixture of ingredients of the adhesive film.

19. The photocured, reactive, pressure-sensitive adhesive film of claim 18, wherein, The fraction of reactive monomers and / or reactive resins is in the range of 20 to 60 wt.%, based on the total mixture of ingredients of the adhesive film.

20. The photocured reactive pressure-sensitive adhesive film according to claim 18, wherein The fraction of reactive monomers and / or reactive resins is in the range of 30 to 50 wt.%, based on the total mixture of ingredients of the adhesive film.

21. The photocured reactive pressure-sensitive adhesive film according to claim 1 or 2, characterized in that, The initiator is a free radical initiator.

22. The photocured reactive pressure-sensitive adhesive film according to claim 1 or 2, characterized in that, The initiator does not initiate polymerization in a mixture with reactive monomers and / or reactive resins at temperatures up to 90°C, even if the mixture is irradiated with UV or blue light.

23. The photocured, reactive, pressure-sensitive adhesive film of claim 21, wherein, The free radical initiator is a peroxycarboxylic acid and a hydroperoxide.

24. The photocured, reactive, pressure-sensitive adhesive film of claim 23, wherein, The hydroperoxide is selected from the group consisting of diisopropylbenzene hydroperoxide, a,a-dimethylbenzyl hydroperoxide, p-menthane hydroperoxide, t-amyl hydroperoxide, t-butyl hydroperoxide and 1,1,3,3-tetramethylbutyl hydroperoxide.

25. The photocured reactive pressure-sensitive adhesive film of claim 21, wherein, The fraction of the free radical initiator is in the range of 0.1 to 10 wt.%, based on the total mixture of ingredients of the adhesive film.

26. The photocured, reactive, pressure-sensitive adhesive film of claim 25, wherein, The fraction of the free radical initiator is in the range of 0.2 to 4 wt.%, based on the total mixture of ingredients of the adhesive film.

27. The photocured reactive pressure-sensitive adhesive film according to claim 25, wherein The fraction of the free radical initiator is in the range of 0.5 to 2 wt.%, based on the total mixture of ingredients of the adhesive film.

28. The photocured reactive pressure-sensitive adhesive film of claims 1 or 2, wherein, The fraction of the photoredox catalyst is in the range of up to 1 wt.%, based on the total mixture of ingredients of the adhesive film.

29. The photocured, reactive, pressure-sensitive adhesive film of claim 28, wherein, The fraction of the photoredox catalyst is in the range of up to 0.5 wt.%, based on the total mixture of ingredients of the adhesive film.

30. The photocured reactive pressure-sensitive adhesive film of claim 28, wherein, The fraction of the photoredox catalyst is in the range of 0.01 to 0.1 wt.%, based on the total mixture of ingredients of the adhesive film.

31. The photocured reactive pressure-sensitive adhesive film according to claim 1 or 2, characterized in that, At least 80 wt.% of the monomers of the polymer (d) are N-vinyl compounds.

32. The photocured reactive pressure-sensitive adhesive film according to claim 1 or 2, characterized in that, At least 90 wt.% of the monomers of the polymer (d) are N-vinyl compounds.

33. The photocured reactive pressure-sensitive adhesive film according to claim 1 or 2, wherein 100 wt.% of the monomers of the polymer (d) are N-vinyl compounds.

34. The photocured reactive pressure-sensitive adhesive film of claims 1 or 2, wherein, The fraction of the polymer (d) is in the range of 5 to 30 wt.%, based on the total mixture of ingredients of the adhesive film.

35. The photocured reactive pressure-sensitive adhesive film of claims 1 or 2, wherein, The fraction of the polymer (d) is in the range of 8 to 25 wt.%, based on the total mixture of ingredients of the adhesive film.

36. The photocured reactive pressure-sensitive adhesive film of claims 1 or 2, wherein, The fraction of the polymer (d) is in the range of 10 to 20 wt.%, based on the total mixture of ingredients of the adhesive film.

37. The photocured reactive pressure-sensitive adhesive film of claims 1 or 2, wherein, The fraction of the film-forming polymer is in the range of 10 to 90 wt.%, based on the total mixture of ingredients of the adhesive film.

38. The photocured, reactive, pressure-sensitive adhesive film of claim 37, wherein, The fraction of the film-forming polymer is in the range of 20 to 60 wt.%, based on the total mixture of ingredients of the adhesive film.

39. The photocured reactive pressure-sensitive adhesive film of claim 37, wherein, The fraction of the film-forming polymer is in the range of 30 to 50 wt.%, based on the total mixture of ingredients of the adhesive film.

40. The photocured reactive pressure-sensitive adhesive film of claim 37, wherein, The fraction of the film-forming polymer is in the range of 35 to 45 wt.%, based on the total mixture of ingredients of the adhesive film.

41. The photocured reactive pressure-sensitive adhesive film according to claim 13, comprising (a) 39 wt.% of at least one reactive monomer or reactive resin, (b) 1.3 wt.% of an initiator, (c) 0.03 wt.% of a photoredox catalyst, (d) 15 wt.% of a polymer obtained by radical polymerization of monomers containing carbon-carbon double bonds, characterized in that these monomers comprise N-vinyl compounds, and (e) 41 wt.% of a film-forming polymer, and (f) 4 wt.% of additives.

42. The photocured reactive pressure-sensitive adhesive film of claims 1 or 2, wherein, The photocured reactive pressure-sensitive adhesive film comprises a mixture of the following ingredients: thermoplastic polyurethane, poly(N-vinylcaprolactam) or poly(N-vinylpyrrolidone), 2-hydroxy-3-phenoxypropyl acrylate or 2-[[(butylamino)carbonyl]oxy]ethyl acrylate, rheological additive, diisopropylhydroperoxide and tris(2,2'-bipyridyl)ruthenium(II) chloride hexahydrate.

43. The photocured reactive pressure-sensitive adhesive film of claims 1 or 2, wherein, The photocured reactive pressure-sensitive adhesive film comprises 35-45 wt.% of a film-forming polymer, 10-20 wt.% of poly(N-vinylcaprolactam) or poly(N-vinylpyrrolidone), 30-50 wt.% of 2-hydroxy-3-phenoxypropyl acrylate or 2-[[(butylamino)carbonyl]oxy]ethyl acrylate, 2-5 wt.% of a rheological additive, 0.5-2.0 wt.% of diisopropylhydroperoxide and 0.01-0.1 wt.% of tris(2,2'-bipyridyl)ruthenium(II) chloride hexahydrate, based on the total mixture of the ingredients of the adhesive film.

44. The photocured reactive pressure-sensitive adhesive film of claims 1 or 2, wherein, The adhesive film has a layer thickness in the range of 20-200 pm.

45. The photocured reactive pressure-sensitive adhesive film of claim 44, wherein, The adhesive film has a layer thickness in the range of 30-100 pm.

46. The photocured reactive pressure-sensitive adhesive film of claim 44, wherein The adhesive film has a layer thickness in the range of 40 to 60 pm.

47. A reactive pressure-sensitive adhesive tape comprising layers (A1), (A2) and (B), characterized in that it comprises a photocured reactive pressure-sensitive adhesive film (A1) according to any one of the preceding claims and a further reactive pressure-sensitive adhesive film (A2) according to any one of the preceding claims, and a film, foil, layer or carrier (B) arranged flat between the two reactive pressure-sensitive adhesive films.

48. A method of manufacturing a reactive pressure-sensitive adhesive adhesive film according to any one of claims 1 to 46, characterized by, The method comprises the following steps, with the exclusion of UV light or visible light of a wavelength that excites the corresponding photoredox catalyst: i. dissolving and / or finely dispersing the ingredients in one or more solvents and / or water, ii. mixing the dissolved or finely dispersed ingredients, iii. coating a film, foil, layer, carrier with the mixture of dissolved or finely dispersed ingredients according to step ii, iv. evaporating the solvent and / or water, v. optionally winding the reactive adhesive film into a roll.

49. The method of claim 48, wherein, The film is an adhesive film.

50. The method of claim 48, wherein, The film is a pressure-sensitive adhesive film.

51. The method of claim 48, wherein, The film is a release paper or release liner. The film is a release paper or release liner.

52. Use of the reactive pressure-sensitive adhesive film according to any one of claims 1 to 46 or of the reactive pressure-sensitive adhesive tape according to claim 47 for producing adhesion on a material selected from plastic, metal, glass or ceramic.

53. Composite element comprising at least two adherend surfaces joined to each other by a cured reactive pressure-sensitive adhesive film according to any one of the preceding claims 1 to 46 or by a cured reactive pressure-sensitive adhesive tape according to claim 47.

Images