EP3861081A1 - Latently reactive adhesive film - Google Patents

Abstract

The invention relates to a thermally curable adhesive film comprising at least one layer of an adhesive comprising at least one epoxy-functionalized (co)polymer (A) having a weight-average molar mass in the range from 5000 g/mol to 5 000 000 g/mol and/or at least one epoxy-containing compound (B) different from the (co)polymer (A); at least one free-radical former (C); and at least one photoacid former (D). The invention further relates to a bond comprising two substrates that are bonded by the adhesive film or the adhesive of the present invention, and to a method of joining two substrates using the adhesive film or the adhesive of the present invention.

Description

 Latent reactive adhesive film

The invention relates to a thermally curable adhesive film, comprising at least one layer of an adhesive

at least one (co) polymer (A) functionalized with epoxy groups with a weight-average molar mass in the range from 5,000 g / mol to 5,000,000 g / mol and / or at least one epoxy-containing compound (B) which is obtained from (Co ) Polymer (A) is different; at least one radical generator (C); and

comprises at least one photo acid generator (D). The invention further relates to a composite comprising two substrates which are bonded by the adhesive film or the adhesive of the present invention, and a method for joining two substrates using the adhesive film of the present invention.

Adhesive films have long been known as a means of bonding two substrates to one another in order to avoid the disadvantages of liquid adhesives. Adhesive films offer the advantages, among other things, of being able to be stored and transported well, being easy to assemble and being easy to apply in the application. Depending on the adhesive used for the adhesive film, good repositioning properties can be achieved with very high adhesive forces. Adhesive tapes are used today in a variety of forms, e.g. B. used as an aid in processes and for connecting different objects. Many self-adhesive tapes that contain pressure sensitive adhesives show permanent stickiness. They can usually perform their connection task immediately after bonding without further hardening. With such self-adhesive tapes, very high bond strengths can sometimes be achieved. Nevertheless, in certain applications there is a need for adhesive solutions that allow even higher bond strengths than classic self-adhesive tapes.

Many such adhesive systems that lead to high-strength bonds are applied in a hot pressing step. The adhesives used - which are often not self-adhesive at room temperature - then melt, wet the surface to be bonded, and build up strength as they solidify as they cool. Such adhesive systems can also have chemical reactivity. Such reactions can increase the cohesion of the adhesive and thus further optimize the bond strength. In addition, such reactions can have a positive impact on chemical resistance and weather resistance. Some reactive adhesives include a polymer composition reactive with a hardener and a corresponding hardener. The polymer has functional groups which can be reacted with corresponding groups of the hardener with appropriate activation. The term “curable adhesives” is therefore understood in the prior art to mean those preparations which contain functional groups which, through the action of a corresponding hardener component in combination with elevated temperature as an additional stimulus, can participate in a reaction which leads to a molecular weight build-up and / or Cross-linking leads to at least one preparation component and / or covalently binds different preparation components to one another. One possibility for this is cationic polymerization.

It is known that cationic polymerization can be initiated thermally by the interaction of a radical generator with a cationic photoinitiator. For example, in Adv. Polym. Sei., 1997, 127, 59 give an overview of various initiators for the activation of a cationic polymerization / curing process for epoxides and vinyl ethers. Initiators that can be activated thermally and / or photochemically are discussed. Free radical-assisted cationic polymerization is also discussed, but with a focus on photochemical activation. Irradiation times are given as 10 minutes to 120 minutes. Fast curing adhesives and latent reactive tapes are not mentioned. The specified response times also do not suggest that systems for rapid curing can be accessed using this concept.

Latent-reactive adhesive tapes which are cured by cationic polymerization are described, for example, in WO 2016/047387 A1, but initiation takes place via a photo acid generator.

The disadvantage of such adhesive tapes which contain a photo acid generator (PAG / Photo Acid Generator) is that production and processing must be carried out in the absence of light and the substrates and / or the adhesive to be cured must be continuous for the activation area. The PAGs are mostly selected from a UV range that can also occur in ambient light or react at least partially under ambient light conditions, since activation in the UVC range or even in the hard UVC range is avoided in the application as far as possible.

It was therefore an object of the present invention to provide latent-reactive adhesive tapes based on 1-component adhesives, which are cured by cationic polymerization are, but do not require cooling during storage, i.e. are stable at room temperature and preferably at 40 ° C. The adhesive tapes should also have typical short activation times, in particular a few minutes, and temperatures, in particular at about 180 ° C. to 220 ° C., preferably up to 200 ° C., particularly preferably at 180 ° C.

The inventor of the present invention has surprisingly found that the object can be achieved by an adhesive tape and / or an adhesive film which contains an adhesive which comprises at least one mixture of at least one (co) polymer (A) functionalized with epoxy groups weight-average molar mass in the range from 5,000 g / mol to 5,000,000 g / mol and / or at least one epoxy-containing compound (B), which is different from (A), at least one specific radical generator (C) and at least one photo acid generator ( D) contains.

It was also surprisingly found that the adhesive systems of the present invention, in contrast to systems which do not contain a specific radical generator and only contain photo acid generators, are suitable for a large number of applications in which non-UV-resistant and / or not to be bonded are to be bonded UV permeable substrates is desired. In particular, an application for black and white and / or products filled with fillers and / or functional fillers is now possible, which has not been possible until now, but which is very much desired by customers.

Other advantages are excellent latency, which can be increased by the additional use of dyes and / or fillers. In addition, the activation range of the system can be set in a targeted manner by specifically selecting the radical generator over its half-life.

Accordingly, in a first aspect, the invention relates to a thermally curable

Adhesive film comprising at least one layer of an adhesive which

at least one (co) polymer (A) functionalized with epoxy groups with a weight-average molar mass in the range from 5,000 g / mol to 5,000,000 g / mol and / or at least one epoxy-containing compound (B) which is obtained from (Co ) Polymer (A) is different; at least one radical generator (C);

at least one photo acid generator (D);

optionally at least one matrix polymer as film former (E); and

optionally at least one additive (F);

includes or consists of. In a second aspect, the invention relates to a composite comprising two substrates which are bonded by an adhesive film or the adhesive according to the present invention. The adhesive itself is not the subject of the present invention. The adhesive of the present invention used in the composite is defined below. It is the same adhesive that is part of the adhesive film. Thus, all of the preferred ones described for the adhesive of the adhesive film are preferred

Embodiments also preferred for the adhesive of the substrate.

In a third aspect, the invention relates to a method for joining two substrates using an adhesive film or an adhesive according to the present invention.

“At least one,” as used herein, refers to 1 or more, for example 2, 3, 4, 5, 6, 7, 8, 9 or more. In connection with constituents of the compound described herein, this information does not refer to the absolute amount of molecules but to the type of constituent. “At least one compound containing epoxy groups” therefore means, for example, one or more different compounds containing epoxide groups, ie one or more different types of epoxy group-containing compounds.

Unless otherwise stated, all of the quantities stated in connection with the adhesive described herein relate to% by weight, based in each case on the total weight of the adhesive. This means that such quantities, for example in connection with “at least one epoxy group-containing compound”, refer to the total amount of epoxy group-containing compounds contained in the adhesive.

Numerical values that are given here without decimal places each refer to the full specified value with one decimal place. For example, “99%” stands for “99.0%”.

The expression “approximately” or “approximately” in connection with a numerical value refers to a variance of ± 10% in relation to the specified numerical value, preferably ± 5%, particularly preferably ± 1%.

The preferred embodiments described below for the individual components (A), (B), (C), (D), (E) and (F) can be applied to all three aspects of the present invention. These and other aspects, features and advantages of the invention will become apparent to those skilled in the art upon studying the following detailed description and claims. Each feature from one aspect of the invention can be used in any other aspect of the invention. Furthermore, it goes without saying that the examples contained herein are intended to describe and illustrate the invention, but not to limit it, and in particular the invention is not restricted to these examples.

The term “(co) polymer” is used collectively for homopolymers or copolymers. Insofar as the term "polymers" is used, it means (co) polymers, unless the respective reference indicates otherwise.

 For the purposes of this invention, the term “(co) poly (meth) acrylate” is understood to mean polyacrylate and polymethacrylate homopolymers or copolymers of (meth) acrylic monomers and, if appropriate, further copolymerizable comonomers.

 The term “(meth) acrylates” and the adjective “(meth) acrylic” summarize the compounds from the group consisting of acrylic acid derivatives - such as, in particular, acrylic acid esters - and methacrylic acid derivatives - such as, in particular, methacrylic acid esters.

 For the purposes of this invention, “(co) polymerizable” means the ability of a monomer type or a mixture of at least two monomer types to form a (co) polymer by increasing the molecular weight.

According to the invention, a (co) polymer (A) functionalized with epoxy groups, which is functionalized in particular with one or more aliphatic epoxy groups and / or an epoxy-containing compound (B), which is different from (A), in which Glue used.

(Co) Pplyrrier (A)

The (co) polymer (A) functionalized with epoxy groups is also referred to below simply as (co) polymer (A). It is particularly preferred that it is a (meth) acrylic (co) polymer.

The (co) polymer (A) has a weight-average molar mass of 5,000 g / mol to 5,000,000 g / mol. In preferred embodiments, the weight-average molar mass of at least one group of a (co) polymer (A) is at least 10,000 g / mol, very preferably at least 20,000 g / mol. The weight-average molar mass of the is also preferably at least one group of a (co) polymer (A) at most 500,000 g / mol, preferably 200,000 g / mol, very preferably at most 100,000 g / mol. The weight average molecular weight is preferably determined as follows in the experimental part by means of GPC.

In alternative preferred embodiments, the weight-average molar mass of the (co) polymer (A) is at least 500,000 g / mol, very preferably at least 1,000,000 g / mol. The weight-average molar mass of the (co) polymer (A) is more preferably at most 5,000,000 g / mol, preferably 3,500,000 g / mol, very preferably at most 2,000,000 g / mol. In particular, if the adhesive contains less than 0.5% by weight, preferably less than 0.1% by weight, of a matrix polymer (E), particularly preferably is free of a matrix polymer (E), based on the total weight of the adhesive.

Corresponding to the proportion in the total of the monomers on which the (co) polymer (A) is based, the (meth) acrylic (co) monomers (a) functionalized with, preferably aliphatic, epoxy groups have a (co) monomer proportion in the (co) polymer ( A) from more than 5 to 100% by weight, preferably from at least 10% by weight, very preferably from at least 25% by weight.

The epoxy oxygen atom preferably bridges a C-C bond, or a C-C-C assembly or a C-C-C-C assembly, in all or some of the epoxy groups in at least some of the monomers functionalized with, preferably aliphatic, epoxy groups.

The epoxy oxygen atom preferably bridges a C-C bond in all or some of the epoxy groups in at least some of the monomers functionalized with aliphatic epoxy groups, which is part of an - optionally hetero-substituted - aliphatic hydrocarbon ring (cycloaliphatic epoxy group).

A (meth) acrylic (co) monomer (a) functionalized with an aliphatic epoxy group, preferably at least one with an aliphatic, preferably cycloaliphatic, epoxy group, is preferably used, or, if more, with one aliphatic epoxy group Functionalized (meth) acrylic (co) monomers (a) are used for one, more or all of these (meth) acrylic (co) monomers (a) cycloaliphatic epoxides functionalized with an aliphatic epoxy group. Cycloaliphatic epoxides are used particularly advantageously for more than 50% by weight of the (co) monomers (a), and particularly cycloaliphatic epoxides are particularly preferably used in the sense of the (co) monomers (a). The (co) polymer (A) can be prepared in addition to monomer (a) from one or more of the monomers (b), (c), and (d), regardless of the presence of the other types of monomers (b), (c ), and (d):

 (b) one or more types of comonomers with a glass transition temperature of at least 25 ° C., in particular at least 50 ° C.,

with a comonomer content in the copolymer from 0% by weight to less than 95% by weight, preferred

0.1% by weight to at most 50% by weight,

and or

 (c) one or more types of comonomers with a glass transition temperature below 25 ° C, in particular at most 0 ° C,

with a comonomer content in the copolymer from 0% by weight to less than 95% by weight, preferably 0.1% by weight to at most 50% by weight,

and or

 (d) one or more types of comonomers which carry at least one functionality other than an epoxy group, in particular a group containing phosphorus or silicon, with a comonomer content in the copolymer of 0% to 10% by weight, preferably 0.1% to 5% by weight.

In the context of this document, the proportion of the repeating units (building blocks) in the polymer in question which are attributable to these (co) monomers is referred to as the proportion of monomers or (co) of monomers in the polymer. The monomer proportions in the polymer mixture to be polymerized for the production of the corresponding copolymer are advantageously chosen accordingly.

The proportion of the (co) polymer (A) in the adhesive is preferably at least 5.0% by weight to at most 99.8% by weight, more preferably 10% by weight to 90% by weight, further preferably 20 % By weight to 80% by weight, further preferably 30% by weight to 70% by weight, further preferably 40% by weight to 60% by weight.

The glass transition temperature of the (co) polymer (A) is preferably at least 0 ° C., very preferably at least 25 ° C., even more preferably at least 35 ° C. It is preferably at most 100 ° C, more preferably at most 80 ° C. In an alternative embodiment of the invention, the glass transition temperature of the (co) polymer (A) can also be below 0 ° C. or above 100 ° C.

(Co) monomers (a)

For the (co) monomers (a), monomers of the formula (I)

used, where -R ¹ is -H or -CH ₃ , -X- is -N (R ³ ) - or -O-, -R ³ is -H or -CH ₃ and -R ^{2 is} an epoxy-functionalized (hetero ) represent hydrocarbyl group. At least one monomer used for -R ^{2 has} an epoxy-functionalized, preferably aliphatic, particularly preferably a cycloaliphatic, group.

The group R ² further preferably comprises linear, branched, cyclic or polycyclic hydrocarbons having 2 to 30 carbon atoms, which are functionalized with an aliphatic epoxy group. At least one monomer used for -R ² preferably has an epoxy-functionalized cycloaliphatic group with 5 to 30 carbon atoms. Particularly preferred representatives of this group are 3,4-epoxycyclohexyl-substituted monomers such as, for example, 3,4-epoxycyclohexylmethyl methacrylate, 3,4-epoxycyclohexylmethyl acrylate, 3,4-epoxycyclohexyl methacrylate, 3,4-epoxycyclohexyl acrylate. Oxetane-containing (meth) acrylates and oxolane-containing (meth) acrylates can also be used. Comonomers (a) in the (co) polymer (A) are used at least 5% by weight, preferably at least 10% by weight, very preferably at least 25% by weight.

Optional comonomers (b)

Comonomers (b) in particular have no epoxy groups. In the sense of the comonomers (b), all (meth) acrylate monomers and other copolymerizable vinyl monomers known to the person skilled in the art, in particular those which are compatible with (co) monomers (a) and any comonomers (c) and / or (d) present, can be used. and / or (e) are copolymerizable and which have a glass transition temperature as a hypothetical homopolymer (in this context, the glass transition temperature of the homopolymer from the corresponding monomers in the molar mass-independent glass transition temperature range, TG “, is meant) of at least 25 ° C., in particular at least 50 ° C. Such monomers are also referred to as “hard monomers” in the context of this document. To select such comonomers z. B. the Polymer Handbook (J. Brandrup, EH Immergut, EA Grulke (ed.), 4th ed., 1999, J. Wiley, Hoboken, Vol. 1, Chapter VI / 193) can be consulted. So-called macromers according to WO 2015/082143 A1 can also be used advantageously. Preference is given to comonomers which, owing to their chemical structure, have essentially no reactivity with the epoxy functionalities of the (co) monomers (a) or initiate or prior to the initiation of the curing reaction act as a catalyst in relation to a reaction of the epoxy functionalities or their reactivity with epoxy functionalities is otherwise prevented.

Optional comonomers (c)

 Comonomers (c) in particular have no epoxy groups. In the sense of the comonomers (c), it is possible to use all (meth) acrylate monomers and other copolymerizable vinyl monomers known to the person skilled in the art, in particular those which are free from epoxy groups and which are combined with (co) monomers (a) and any comonomers (b) and / or (d) are copolymerizable, and which have a glass transition temperature as a hypothetical homopolymer (in this context, the glass transition temperature of the homopolymer from the corresponding monomers in the molar mass-independent glass transition temperature range, TG “, is meant) of below 25 ° C., in particular at most 0 ° C. Such monomers are also referred to as “soft monomers” in the context of this document. The polymer handbook (J. Brandrup, E. H. Immergut, E. A. Grulke (ed.), 4th edition, 1999, J. Wiley, Hoboken, Vol. 1, Chapter VI / 193) can be consulted, for example, on the selection of such comonomers. So-called macromers according to WO 2015/082143 A1 can also be used advantageously. Preference is given to comonomers which, by virtue of their chemical structure, have essentially no initiating or catalyzing action in relation to a reaction of the epoxy functionalities before the initiation of the curing reaction, in particular which have no reactivity with the epoxy functionalities of the (co) monomers (a) and / or whose reactivity with epoxy functionalities is otherwise prevented.

Optional comonomers (d)

 In the sense of the comonomers (d), it is also possible to use monomers which can be copolymerized with (co) monomers (a) and any comonomers (b) and / or (c) present and which optimize the adhesive properties of the copolymer according to the invention. In this connection, phosphorus-containing and silicon-containing comonomers and here acrylated or methacrylated alkoxysilane-containing comonomers are particularly advantageous. Examples are 3- (triethoxysilyl) propyl methacrylate, 3- (triethoxysilyl) propyl acrylate, 3- (triethoxysilyl) propyl acrylate, 3-

(Trimethoxysilyl) propyl methacrylate, methacrylic oxymethyltriethoxysilane,

(Methacryloxymethyl) trimethoxysilane, (3-acryloxypropyl) methyldimethoxysilane,

(Methacryloxymethyl) methyldimethoxysilane, y-methacryloxypropylmethyldimethoxysilane, methacryloxypropylmethyldiethoxysilane, 3- (dimethoxymethylsilyl) propyl methacrylate,

Methacryloxypropyldimethylethoxysilane, methacryloxypropyldimethylmethoxysilane. Of the aforementioned compounds, 3- (triethoxysilyl) propyl methacrylate, 3- (triethoxysilyl) propyl acrylate, 3- (trimethoxysilyl) propyl acrylate and 3- (trimethoxysilyl) propyl methacrylate particularly preferred. The comonomers (d) also preferably have no glycidyl ether or epoxy groups. The proportion of comonomers (d) is preferably at most 10% by weight, based on the total weight of the copolymer. In an advantageous embodiment of this invention, a (co) polymer contains comonomer (d). In a further advantageous embodiment of this invention, comonomers (d) are completely dispensed with.

In a preferred embodiment, the (co) polymer (A) contains no Si-containing monomers. In a further preferred embodiment, the (co) polymer (A) is pressure-sensitive.

Manufacturing

 The (co) polymers (A) are prepared by (co) polymerizing the underlying (co) monomers and can be carried out in bulk, in the presence of one or more organic solvents, in the presence of water or in mixtures of organic solvents and water. The aim is to keep the amount of solvent used as low as possible. Suitable organic solvents are pure alkanes (for example hexane, heptane, octane, isooctane, isohexane, cyclohexane), aromatic hydrocarbons (for example benzene, toluene, xylene), esters (for example ethyl acetate, propyl, butyl or hexyl acetate) halogenated hydrocarbons (e.g. chlorobenzene), alkanols (e.g. methanol, ethanol, ethylene glycol, ethylene glycol monomethyl ether), ketones (e.g. acetone, butanone) and ethers (e.g. diethyl ether, dibutyl ether) or mixtures thereof. There are no compounds which can react with epoxy functionalities before the initiation of the curing reaction, or which can initiate or catalyze the reaction of epoxy functionalities, or whose reactivity with epoxy functionalities is otherwise prevented.

A water-miscible or hydrophilic cosolvent can be added to the aqueous polymerization reactions to ensure that the reaction mixture is in the form of a homogeneous phase during the monomer conversion. Cosolvents which can be used advantageously for the present invention are selected from the following group consisting of aliphatic alcohols, glycols, ethers, glycol ethers, polyethylene glycols, polypropylene glycols, esters, alcohol derivatives, hydroxyether derivatives, ketones and the like, as well as derivatives and mixtures thereof. There are no compounds which can react with epoxy functionalities and / or which can initiate or catalyze the reaction of epoxy functionalities and / or whose reactivity with epoxy functionalities is not otherwise prevented. Conventional free-radical polymerizations or controlled free-radical polymerizations are advantageously carried out to produce the (co) polymers (A) according to the invention. Initiator systems which contain radical initiators for the polymerization (polymerization initiators), in particular thermally decomposing radical-forming azo or peroxo initiators, are preferably used for the free-radical polymerizations. In principle, however, all of the customary polymerization initiators familiar to those skilled in the art are suitable for acrylates and / or methacrylates. The production of C-centered radicals is described in Houben-Weyl, Methods of Organic Chemistry, Vol. E 19a, pp. 60-147. These methods are preferably applied in analogy.

 The radical polymerization initiators mentioned in connection with the production of the (co) polymers (A) should not be confused with the hardeners or activators used for curing the curable adhesive.

Examples of radical sources are peroxides, hydroperoxides and azo compounds. Some non-exclusive examples of typical radical initiators are potassium peroxodisulfate, dibenzoyl peroxide, cumene hydroperoxide, cyclohexanone peroxide, di-tert-butyl peroxide, azobisiisobutyronitrile, cyclohexylsulfonylacetyl peroxide, diisopropyl percarbonate, tert-butyl peracololate. 2,2'-Azobis (2-methylbutyronitrile) or 2,2-azobis (2,4-dimethylvaleronitrile) is particularly preferably used as the radical polymerization initiator.

 Depending on the temperature and the desired conversion, the polymerization time is between 4 and 72 hours. The higher the reaction temperature that can be selected, that is, the higher the thermal stability of the reaction mixture, the shorter the reaction time that can be selected.

 To initiate the polymerization, the entry of heat is essential for the thermally decomposing polymerization initiators. The polymerization can be initiated for the thermally decomposing polymerization initiators by heating to 50 ° C. or more, depending on the type of initiator. An initiation temperature of at most 100 ° C. is preferred, very preferably of at most 80 ° C.

 To stabilize radicals, nitroxides are used in a favorable manner, such as, for. B. (2,2,5,5-tetramethyl-1-pyrrolidinyl) oxyl (PROXYL), (2,2,6,6-tetramethyl-1-piperidinyl) oxyl (TEMPO), derivatives of PROXYL or TEMPO and others nitroxides familiar to the person skilled in the art.

A number of other polymerization methods by which the adhesives can be produced in an alternative procedure can be selected from the prior art: WO 96/24620 A1 describes a polymerization process in which very special radical compounds such as. B. phosphorus-containing nitroxides based on imidazolidine, be used. WO 98/44008 A1 discloses special nitroxyls based on morpholines, piperazinones and piperazine dions. DE 199 49 352 A1 describes heterocyclic alkoxyamines as regulators in controlled radical polymerizations. Atom Transfer Radical Polymerization (ATRP) can be used as a further controlled polymerization method, preferably monofunctional or difunctional secondary or tertiary halides as the polymerization initiator and for the abstraction of the halide (s) Cu, Ni, Fe, Pd, Pt, Ru, Os, Rh, Co, Ir, Ag or Au complexes can be used. The different possibilities of the ATRP are further described in the documents US 5,945,491 A, US 5,854,364 A and US 5,789,487 A.

As a further manufacturing process, a variant of RAFT polymerization (reversible addition-fragmentation chain transfer polymerization) is carried out. The polymerization process is e.g. B. in the writings WO 98/01478 A1 and WO 99/31144 A1 described in detail. Trithiocarbonates of the general structure R '"- S-C (S) -S-R"' (Macromolecules, 2000, 33, 243-245) are particularly advantageous for the preparation.

In a very advantageous variant, for example, the trithiocarbonates (TTC1) and (TTC2) or the thio compounds (TH11) and (THI2) are used for the polymerization, where F is a phenyl ring which is unfunctionalized or by alkyl or aryl substituents which are used directly or via ester or linked ether bridges, can be functionalized, can be a cyano group or a saturated or unsaturated aliphatic radical. The phenyl ring F can optionally carry one or more polymer blocks, for example polybutadiene, polyisoprene or polystyrene, to name just a few. Functionalizations can be, for example, halogens, hydroxy groups, epoxy groups, without this list claiming to be complete.

'TH 1} (THI 2 | In connection with the above-mentioned controlled free-radical polymerizations, polymerization initiator systems are preferred which contain free radical polymerization initiators, in particular the thermally decomposing radical-forming azo or peroxo initiators listed above. In principle, however, all conventional polymerization initiators known for acrylates and / or methacrylates are suitable. In addition, radical sources can also be used which only release radicals under UV radiation. It is essential that these polymerization initiators cannot activate a reaction of the epoxy functionalities.

For the purpose of adjusting the molar mass, chain transfer reagents according to the prior art can also be used, provided that they have no reactivity towards epoxy groups or their reactivity with epoxy groups is otherwise prevented.

 The desired molar mass is preferably set by polymerization processes, be it controlled polymerization processes or uncontrolled polymerization processes, in which no agents are used which can react with epoxy functionalities before the initiation of the curing reaction of the adhesive film or initiate or catalyze the reaction of epoxy functionalities can or their reactivity with epoxy functionalities is otherwise prevented.

 The setting of the desired molar mass can moreover be carried out particularly preferably via the use ratio of polymerization initiators and (co) monomer (s) and / or the concentration of (co) monomers.

E poxicFG ru ppen _. e _. nth old connection (B)

Glycidyl ether group-containing (co) polymers (B1) and / or other glycidyl ethers (B2) and / or epoxides (B3) are particularly preferred.

Glycidyl ether group-containing (co) polymers (B1) can be obtained analogously to the (co) polymers (A) described above, only the monomer (a) is replaced or replaced by a glycidyl ether group-containing monomer (e) Glycidyl ether group-containing monomer (s) added. Glycidyl acrylate or glycidyl methacrylate are particularly preferred as monomers (e). All preferred embodiments for the (co) polymer (A) described above with regard to the monomers (b), (c) and (d) and the properties of the (co) polymer, such as, for example, the weight-average molecular weight, are preferred as described for (A) above . This is typically at least 5000 g / mol and at most 5,000,000 g / mol. Preferred glycidyl ethers (B2) are at least difunctional or tri, tetra or higher functional with respect to the glycidyl ether groups contained in the compound and have a molecular weight of 58 to below 5,000 g / mol, preferably 58 to 1,000 g / mol. For example, diglycidyl ethers of a polyoxyalkylene glycol or glycidyl ether monomers are suitable. Examples are the glycidyl ethers of polyhydric phenols obtained by reacting a polyhydric phenol with an excess of chlorohydrin such as epichlorohydrin (e.g. the diglycidyl ether of 2,2-bis (2,3-epoxypropoxyphenol) propane).

Further examples which can be used are tetrahydrophthalic acid diglycidyl ester and derivatives, hexahydrophthalic acid diglycidyl ester and derivatives, 1,2-ethanediglycidyl ether and derivatives, 1,3-propanediglycidyl ether and derivatives, 1,4-butanediol diglycidyl ether and derivatives, and higher 1, n-alkyldidyl ether and derivatives, higher 1, n- alkyldidyl ether and derivatives, higher 1, n-alkyl ether and derivatives, and derivatives, bis [1-ethyl (3-oxetanyl) methyl) ether and derivatives, pentaerythritol tetraglycidyl ether and derivatives, bisphenol A digylcidyl ether (DGEBA), hydrogenated bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, hydrogenated bisphenol F -Diglycidyl ether, epoxyphenol novolaks, hydrogenated epoxyphenol novolaks, epoxycresol novolaks, hydrogenated epoxycresol novolaks, 2- (7-oxabicyclospiro (1, 3-dioxane-5,3 '- (7-oxabicyclo [4.1.0] -heptane )), 1, 4-bis ((2,3-epoxypropoxy) methyl) cyclohexane.

Preferred epoxide groups (B3) containing epoxide groups have a molecular weight of 58 to below 5,000 g / mol, preferably 58 to 1,000 g / mol and are different from (B2).

In a preferred embodiment, the proportion of (B) in the adhesive is at least 5.0% by weight to at most 99.8% by weight, more preferably 10% by weight to 90% by weight, further preferably 20% by weight % to 80% by weight, further preferably 30% by weight to 70% by weight, further preferably 40% by weight to 60% by weight.

If both (A) and (B) are present, their total content is preferably at least 5.0% by weight to at most 99.8% by weight, more preferably 10% by weight to 90% by weight , further preferably 20% by weight to 80% by weight, further preferably 30% by weight to 70% by weight, further preferably 40% by weight to 60% by weight.

Radj kaj bi [d n er _ (C)

The adhesive also contains at least one specific radical generator (C) The radical generator (C) according to the present invention preferably contains at least two organyl groups.

Particularly suitable radical formers (C) are peroxides (C1) and azo compounds (C2).

The peroxides (C1) are in particular those which carry an organyl group on each oxygen atom. Accordingly, preferred peroxides are compounds of the general structure ROOR ', where the radicals R and R' are organyl groups which can be selected independently of one another or can be identical, and where R and R 'can also be linked to one another, so that a cycle with R and R 'is formed via the peroxy group (-OO-). The peroxide (C1) preferably has a 1-minute half-life temperature of less than 200 ° C. in solution.

Organyl groups are organic radicals - regardless of which functional group they contain - with one or more rarely several free valences on one carbon atom. Examples include acetonyl groups, acyl groups (e.g. acetyl groups, benzoyl groups), alkyl groups (e.g. methyl groups, ethyl groups), alkenyl groups (e.g. vinyl groups, allyl groups), alkynyl groups (propargyl groups), aminocarbonyl groups, ampicilloyl groups (residues derived from ampicillin), aryl groups ( for example phenyl groups, 1-naphthyl groups, 2-naphthyl groups, 2-thiophenyl groups, 2,4-dinitrophenyl groups), alkylaryl groups (for example benzyl groups, triphenylmethyl groups), benzyloxycarbonyl groups (Cbz), tert-butoxycarbonyl groups (Boc), carboxy groups, (fluorene -9-ylmethoxy) carbonyl groups (Fmoc), furfuryl groups, glycidyl groups, haloalkyl groups (for example chloromethyl groups, 2,2,2-trifluoroethyl groups), indolyl groups, nitrile groups, nucleosidyl groups, trityl groups, to name just a few.

Peroxides of the general structure ROOR '(also in cyclic form) have the advantage, for example, in comparison to the hydroperoxides that they do not release water in the sense of primary cleavage products when the adhesive is thermally activated. According to the invention, it is preferred to reduce volatile constituents with boiling points below 120 ° C., preferably with boiling points below 150 ° C., as far as possible, preferably to avoid them completely, in particular to avoid blistering in the bond point and thus its weakening. Accordingly, R and R 'of the peroxides according to the invention are particularly preferably to be selected such that they are not easy to form volatile primary fission products - such as carbon dioxide, isopropanol - lead.

According to the invention, the at least one radical generator, or the plurality of radical generators used, is preferably selected such that it has comparatively high decay rates or low half-lives [t-1 _/ 2] at elevated temperatures - temperatures above its activation temperature. The rate of decay of the radical formers is a characteristic criterion for their reactivity and is quantified by stating the half-lives at certain temperatures [ti _/ 2 (T)], the half-life, as usual, representing the time after which half of the radical formers under the specified conditions has crumbled. The higher the temperature, the shorter the half-life of the decay. So the higher the rate of decay, the lower the half-life. The half-life temperature [T (t-1 _/ 2)] is the temperature at which the half-life corresponds to a predetermined value, for example the 10-hour half-life temperature [T (ti _{/ 2} = 1 Oh)] is the temperature at the half-life of the investigated substance is just 10 hours, the 1-minute half-life temperature [T (ti _{/ 2} = 1 min)], the temperature at which the half-life of the investigated substance is just 1 minute, and accordingly.

In preferred embodiments, the at least one radical generator, or the plurality of radical generators used, is selected such that the 1-minute half-life temperature T (ti _{/ 2} = 1 min) in solution does not exceed 200 ° C., preferably does not exceed 190 ° C. very preferably does not exceed 180 ° C.

The above condition is in particular considered to be met if the peroxide in question has a corresponding half-life temperature value at least in monochlorobenzene (0.1 molar solution). Such half-lives can be determined experimentally (concentration determination using DSC or titration) and can also be found in the relevant literature. The half-lives can also be obtained by calculation from the Arrhenius frequency factor and decay activation energy specific for the respective peroxide for the given conditions. The following relationships apply:

 - dc / dt = k-c [1]

 In (C1 / C0) = -k-t [2]

ti _{/ 2} = In2 / k for c _t (ti _{/ 2} ) = Co / 2 [3}

k = Ae ^{Ea / RT} [4] where Co = initial concentration

 Ct = concentration at time t

C _t (ti _/ 2) = concentration at half-life

 ti / 2 = half-life

 k = decay constant

 A = Arrhenius frequency factor

 Ea = activation energy for peroxide decay

 R = general gas constant (R = 8.3142 J / (mol-K))

 T = absolute temperature

The half-lives mentioned in this document and the half-life temperatures each relate to a 0.1 molar solution of the corresponding peroxide in monochlorobenzene, unless stated otherwise.

Using the constants Arrhenius frequency factor and decay activation energy, which can be researched for the respective conditions - such as the solvent used - or can be calculated from researchable values, the half-lives and the half-life temperatures can be converted to other conditions - such as in other solvents - and thus made comparable .

Radical formers are preferred which, at moderate temperatures - especially those well below their activation temperatures - also have high half-lives. Good latency behavior, that is to say good storage stability, can be achieved with the thermally activatable adhesive films comprising the radical formers. Accordingly, the at least one radical generator, or the plurality of radical generators used, is preferably chosen such that its or its half-life at 80 ° C. - that is to say after a pre-laminating process - is preferred for at least 13.5 hours, in particular at least 22.5 hours is at least 69 hours, particularly preferably at least 700 hours. This makes it possible for the thermally activatable adhesive tape to have a sufficient processing and application time at 80 ° C, in that after an hour at least 95% of the radical generator originally used (corresponding to ti / 2 = 13.5 h), in particular at least still 97% (corresponding to ti / 2 = 22.5 h), preferably still at least 99% (corresponding to ti / 2 = 69 h), particularly preferably still at least 99.9% of the radical generator used and are therefore not yet available for a reaction . In order to guarantee a storage-stable system, the half-life should be long under normal storage conditions - which can usually be up to 40 ° C. The radical formers used should therefore preferably be chosen such that their half-life at the storage temperature, preferably still up to 40 ° C., is sufficiently long that after 9 months (274 days) at least 75%, preferably 85%, particularly preferably 95% or very particularly preferably more than 95% of the radical generator is available for the crosslinking. The corresponding half-lives can be determined using the relationships mentioned above.

Radical formers suitable according to the invention are, for example, representatives from the following groups:

 Dialkyl peroxides, diacyl peroxides, peroxy esters, peroxidicarbonates, peroxy ketals, cyclic peroxides, for which the values mentioned with regard to 1-minute half-life temperature, preferably also with respect to half-life at 80 ° C., more preferably also with respect to half-life at 40 ° C., are realized.

A few representatives from the various groups to which this can be used may be mentioned below by way of example:

 Dialkyl peroxides: di-tertiary amyl peroxide, di-tertiary butyl peroxide, tertiary butyl cumyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di (tert-butyl peroxy) hexane, 2,5-dimethyl -2,5-di (tert-butylperoxy) hexyn-3, di- (2-tert-butylperoxyisopropyl) benzene;

 Diacyl peroxides. Dibenzoyl peroxide, dilauroyl peroxide, diisobutyryl peroxide, didecanoyl peroxide, di- (3,5,5-trimethyl-hexanoyl) peroxide;

 Ketone peroxides \ acetylacetone peroxide, cyclohexanone peroxide, methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide;

 Peroxyester. tert-butyl peroxy acetate, tert-butyl peroxybenzoate, tert-butyl peroxy diethyl acetate, tert-amyl-peroxy-2-ethylhexyl carbonate, tert-butyl peroxy-isopropyl carbonate, tert-butyl peroxy-2-ethyl hexyl carbonate, tert-amyl peroxy-2-ethyl hexanoate , tert-Butylperoxy-2-ethylhexanoate, 1, 1, 3,3-tetramethylbutylperoxy-2-ethylhexanoate, tert.-Butylperoxy-3,5,5-trimethylhexanoate, tert.-Butyl-peroxyisobutyrate, tert.-Butylmonoperoxymaleate, tert .-Amylperoxineodecanoate, tert.-butyl-peroxyneodecanoate, cumene peroxyneodecanoate, 1, 1, 3,3-tetramethylbutyl-peroxyneodecanoate, tert.-butylperoxyneoheptanoate, tert.-amylperoxypivalate, tert.-butylperoxypatylate, tetramethylpivalate, 1, 1yp. 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane;

Peroxidicarbonates. Di-n-peroxidicarbonate, di- (2-ethylhexyl) peroxydicarbonate, di-n-butylperoxydicarbonate, dicetyl-peroxydicarbonate, dimyristylperoxydicarbonate, di- (4-tert-butylcyclohexyl) peroxydicarbonate; Peroxyketals: 1,1-di (tert-butyl peroxy) -3,3,5-trimethylcyclohexane, 1,1-di (tert-butyl peroxy) cyclohexane, 2,2-di (tert-butyl peroxy) -butane;

 Cyclic peroxides: 3,6,9-triethyl-3,6,9-trimethyl-1, 4,7-triperoxonane.

According to the invention, dicumyl peroxide (bis (1-methyl-1-phenylethyl) peroxide) is used particularly advantageously. This has the following half-lives: 812 h at 80 ° C (corresponding to less than 0.1% of the original amount of peroxide at 80 ° C within one hour); 10 h at 1 12 ° C; 1 h at 132 ° C; 0.1 h = 6 min at 154 ° C; 1 min at 172 ° C; all of the above values in solution (0.1 molar monochlorobenzene). Dicumyl peroxide is particularly preferably selected, since it can be used to obtain adhesive films which are particularly stable in storage and also heat-resistant. Two or more radical formers can also be used. In a preferred procedure, dicumyl peroxide is then selected as one of the two or more radical formers.

Suitable azo compounds (C2) are in principle all the usual azo initiators known to (meth) acrylates to the person skilled in the art, as disclosed, for example, in Houben Weyl, Methods of Organic Chemistry, Vol. E 19a, pp. 60-147.

The radical generator (s) used, in particular dicumyl peroxide, are - preferably depending on their reactivity - preferably chosen in an amount such that the resulting adhesive bonded film has the desired properties and in particular the specifications in the push-out tests defined in more detail below Fulfills. The adhesives used in accordance with the invention and the corresponding adhesive films are latently reactive. In the context of this invention, adhesive systems which can be activated and which can be stably stored over long periods of time without activation are referred to as latent-reactive. Latent-reactive adhesive films are preferably those that do not or only over a period of time in a normal climate (23 ° C [296.15 K]; 50% rh) and in particular at elevated storage temperatures (in particular up to 40 ° C [316.15 K]) harden for several weeks, preferably months, and are therefore stable in storage, but which can be activated at higher temperatures and harden and / or crosslink. The latent reactivity has the advantage that these adhesive films can be stored, transported and further processed (e.g. assembled) in normal climates and in particular at elevated temperatures up to 40 ° C, before they are used at the bond point and hardened.

The adhesives should not change significantly during the storage period, so that the adhesive properties of a freshly used adhesive system after manufacture and one after a longer storage for the otherwise comparable one Do not significantly differentiate the adhesive system used, in particular, however, at least still meet the requirement profile (push-out> 1.5 MPa), preferably at least 50%, particularly preferably at least 75%, very particularly preferably at least 90% of the performance of the non-stored Have adhesive film.

 More preferably, the adhesive films are also stable with regard to the defined damp-heat behavior, ie in the push-out test of the adhesive composite, even after the adhesive film has been stored for a long time, before the composite is produced, for at least 3 weeks, preferably at least 4 weeks at 40 ° C in a commercially available, suitable circulating air drying cabinet (drying rank is in the standard climate (23 ° C and 50% RH)), and after further moist heat storage (72 h at 85 ° C and 85% RH, F,) the adhesive bond produced is only permissible Deviations from the corresponding values of an adhesive composite from appropriately stored adhesive films, but without the composite being stored in moist heat.

 In addition - in combination with the aforementioned minimum values - the bond strength - in the sense of the aforementioned push-out force value - of the adhesive bonded assembly stored in the moist heat storage should preferably be more than 50% of the bonded bond bonded not under the heat storage, more preferably the bond strength of the bonded bonded assembly under the moist heat be more than 75% of the non-moist heat-stored adhesive composite, and very preferably the bond strength of the moist-heat-stored adhesive composite should be more than 90% of the non-moist-heat stored adhesive composite or even exceed the value of the non-moist heat-stored composite.

 The compositions according to the invention are distinguished in that, on the one hand, they are latently reactive and, on the other hand, they can be quickly hardened at elevated temperature. In order to meet these requirements, amounts of free radical formers - for example the amount of dicumyl peroxide - have been at least 0.1% by weight, advantageously at least 1% by weight, particularly advantageously at least 2% by weight, very particularly advantageously at least 3% by weight , and of a maximum of 10% by weight, preferably a maximum of 8% by weight, very preferably a maximum of 7% by weight, have been found to be very advantageous.

Photo acid generator _. (DJ

The person skilled in the art is familiar with photoacid generators, preferably at least one of the compounds listed below is used. In particular, sulfonium, iodonium and metallocene-based systems can be used as photo acid generators for cationic UV-induced curing. As examples of sulfonium-based cations, reference is made to the explanations in US Pat. No. 6,908,722 B1 (in particular columns 10 to 21). Aryldiazonium salts ("onium salts"), which can generally be represented by the formula Ar-N = N + LX ", are also preferably used as photoacid generators (also called" photo cation generators "or" photoinitiators "), where LX" is an adduct of a Lewis acid L and one Lewis base X "is used. BF4 ~, SbF5", AsF5 ~ PF5 ", SO3CF2 - for LX" are particularly advantageous. Under the influence of UV radiation, the molecules are rapidly split into the aryl halide (ArX), nitrogen and the corresponding Lewis acid.

Aryliodonium salts (C ₆ H ₅ ) RI + LX ", where R is an organic radical, in particular diaryliodonium salts (C6H ₅ ) 2l + LX", and triarylsulfonium salts (C6H ₅ ) 3S + LX "are also known for use as cationic photoinitiators; these form in the presence of proton donors strong (Brönstedt) acids, which are also well suited for the initiation of cationic polymerizations and for the inventive method.

Sulfonium salts as cation photoinitiators are also present, for example, in the form of the compounds H5C6-CO-CH2-S + LX "or H ₅ C6-CO-CH2-Pyr + LX", where Pyr is a nitrogen-containing heteroaromatic system (eg pyridine, pyrimidine).

In a preferred embodiment, the photoacid generator is a triarylsulfonium hexafluoro salt of the 15th group of the periodic table, the element of the 15th group preferably being in oxidation state IV. Triarylsulfonium hexafluorophosphate and / or triarylsulfonium hexafluoroantimonate are used very favorably.

Examples of anions which serve as counterions are tetrafluoroborate, tetraphenylborate, hexafluorophosphate, perchlorate, tetrachloroferrate, hexafluoroarsenate, hexafluoroantimonate, pentafluorohydroxyantimonate, hexachloroantimonate,

Tetrakispentafluorophenylborate, tetrakis (pentafluoromethylphenyl) borate, bi-

(Trifluoromethylsulfonyl) amides and tris (trifluoromethylsulfonyl) methides called. Furthermore, chloride, bromide or iodide are also conceivable as anions, in particular for iodonium-based initiators, but initiators which are essentially free of chlorine and bromine are preferred.

Examples of preferred photo acid generators are the following compounds:

Sulfonium salts (see, for example, US 4,231, 951 A, US 4,256,828 A, US 4,058,401 A, US 4,138,255 A and US 2010/063221 A1) such as triphenylsulfonium hexafluoroarsenate,

Triphenylsulfonium hexafluoroborate, triphenylsulfonium tetrafluoroborate, Triphenylsulfonium tetrakis (pentafluorobenzyl) borate,

 Methyldiphenylsulfonium tetrafluoroborate, methyldiphenylsulfonium tetrakis

(pentafluorobenzyl) borate, dimethylphenylsulfonium hexafluorophosphate,

Triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate,

Diphenylnaphthylsulfonium hexafluoroarsenate, tritolylsulfonium hexafluorophosphate,

Anisyldiphenylsulfonium hexafluoroantimonate, 4-

Butoxyphenyldiphenylsulfonium tetrafluoroborate, 4-

Chlorophenyldiphenylsulfoniumhexafluoroantimonat, tris (4-phenoxyphenyl) - sulfonium hexafluorophosphate, di (4-ethoxyphenyl) -methylsulfoniumhexafluoroarsenat, 4- Acetylphenyldiphenylsulfoniumtetrafluoroborat, 4-Acetylphenyldiphenylsulfoniumtetrakis- (Pentafluorobenzyl) borate, T RIS (4-thiomethoxyphenyl) -sulfoniumhexafluorophosphat, di- ( methoxysulfonylphenyl) methylsulfonium hexafluoroantimonate, di (methoxynaphthyl) methylsulfonium tetrafluoroborate, di (methoxynaphthyl) methylsulfoniumetrakis (pentafluorobenzyl) borate, di (carbomethoxyphenyl) hexafluorophenyl (methyl) sulfonate bis-trifluoromethylphenyl) borate, T ris- [4- (4-acetylphenyl) thiophenyl] sulfonium tetrakis (pentafluorophenyl) borate, tris (dodecylphenyl) sulfonium tetrakis (3,5-bis-trifluoromethylphenyl) - borate, 4-acetamidophenyldiphenylsulfonium tetrafluoroborate, 4-acetamidophenyldiphenylsulfonium tetrakis (pentafluorobenzyl) borate, dimethylnaphthylsulfonium hexafluorophospha t, T rifluoromethyldiphenyl- sulfoniumtetrafluoroborat, Trifluoromethyldiphenylsulfoniumtetrakis- (Pentafluorobenzyl) - borate, Phenylmethylbenzylsulfoniumhexafluorophosphat, hexafluorophosphate 5-Methylthianthreniumhexa-, 10-phenyl-9,9-dimethylthioxantheniumhexafluorophosphat, oxothioxantheniumtetrafluoroborat 10-phenyl-9, 10-phenyl-9-oxothioxantheniumtetrakis- ( pentafluorobenzyl) borate, 5-methyl-10-oxothianthrenium tetrafluoroborate, 5-methyl-10-oxothianthrenium umtetrakis (pentafluorobenzyl) borate and 5-methyl-10,10-dioxothianthrenium hexafluorophosphate, iodonium salts (see for example US 3,729,313 A, US 3,741, 769 A, US 4,250,053 A, US 4,394,403 A and US 2010/063221 A1) as

Diphenyliodonium tetrafluoroborate, di- (4-methylphenyl) iodonium tetrafluoroborate, phenyl-4-methylphenyliodonium tetrafluoroborate, di- (4-chlorophenyl) iodonium hexafluorophosphate, dinaphthyliodonium tetrafluoroborium, di-4-trifluoroborium, di-4-trifluoroborium iodonium hexafluorophosphate, diphenyl iodonium hexafluoroarsenate, di- (4-phenoxyphenyl) iodonium tetrafluoroborate, phenyl 2-thienyl iodonium hexafluorophosphate, 3,5-dimethylpyrazolyl-4-phenyl iodonium hexafluorophosphate, 2,2 phenyl iodonyl hexonium dichloro diphonate, 2,2 phenyl iodonium fluoride , Di- (4-bromophenyl) iodonium hexafluorophosphate, di- (4-methoxyphenyl) iodonium hexafluorophosphate, di- (3-carboxyphenyl) iodonium hexafluorophosphate, di- (3- methoxycarbonylphenyl) -iodoniumhexafluorophosphat, di (3-methoxysulfonylphenyl) - iodonium hexafluorophosphate, di (4-acetamidophenyl) -iodoniumhexafluorophosphat, di- (2-benzothienyl) -iodoniumhexafluorophosphat, Diaryliodoniumtristrifluormethylsulfonylmethid diphenyliodonium hexafluoroantimonate, Diaryliodoniumtetrakis- (pentafluorophenyl) borate as Diphenyliodoniumtetrakis- such as ( pentafluorophenyl) borate, (4-n-desiloxyphenyl) phenyliodonium hexafluoroantimonate, [4- (2-hydroxy-n-tetradesiloxy) phenyl] phenyliodonium hexafluoroantimonate, [4- (2-hydroxy-n-tetradesiloxy) phenyl] phenyliodonium sulfonate , [4- (2-Hydroxy-n-tetradesiloxy) phenyl] phenyliodonium hexafluorophosphate, [4- (2-Hydroxy-n-tetradesiloxy) phenyl] phenyliodonium tetrakis (pentafluorophenyl) borate, bis (4-tert- butylphenyl) iodonium hexafluoroantimonate, bis (4-tert-butylphenyl) iodonium hexafluorophosphate, bis (4-tert-butylphenyl) iodonium trifluorosulfonate, bis (4-tert-butylphenyl) iodonium tetrafluoroborate, bis (dodecyl) l) -iodonium hexafluoroantimonate, bis- (dodecylphenyl) - iodonium tetrafluoroborate, bis- (dodecylphenyl) -iodonium hexafluorophosphate, bis- (dodecylphenyl) -iodonium trifluoromethylsulfonate, di- (dodecylphenyl) -diodonyl-phenyl-di-iodonyl-dodonyl-di-iodonyl-phenyl-di-iodonyl-phenyl-iodonyl-phenyl-di-iodonyl-dodonyl-dodonyl-iodonium-iodon-iodon-iodon-iodon-iodon-iodon-i-4-yl '-Dichlorodiphenyliodoniumbisulfat, 4,4'-Dibromodiphenyliodoniumbisulfat, 3,3'-

Dinitrodiphenyliodoniumbisulfat, 4,4'-Dimethyldiphenyliodoniumbisulfat, 4,4'-Bis-succinimidodiphenyliodoniumbisulfat, 3-Nitrodiphenyliodoniumbisulfat, 4,4'-

Dimethoxydiphenyl iodonium bisulfate, bis (dodecylphenyl) iodonium tetrakis

(pentafluorophenyl) borate, (4-octyloxyphenyl) phenyliodonium tetrakis (3,5-bis-trifluoromethylphenyl) borate and (tolylcumyl) iodonium tetrakis (pentafluorophenyl) borate, and ferrocenium salts (see for example EP 0 542 716 B1) Like n5- (2,4-cyclopentadien-1-yl) - [(1, 2,3,4,5,6,9) - (1-methylethyl) benzene] iron.

Examples of commercialized photoinitiators are Cyracure UVI-6990, Cyracure UVI-6992, Cyracure UVI-6974 and Cyracure UVI-6976 from Union Carbide, Optomer SP-55, Optomer SP-150, Optomer SP-151, Optomer SP-170 and Optomer SP-172 from Adeka, San-Aid SI-45L, San-Aid SI-60L, San-Aid SI-80L, San-Aid SI-100L, San-Aid SI-1 1 OL, San-Aid SI-150L and San-Aid SI-180L from Sanshin Chemical, SarCat CD-1010, SarCat CD-101 1 and SarCat CD-1012 from Sartomer, Degacure K185 from Degussa, Rhodorsil Photoinitiator 2074 from Rhodia, CI-2481, CI- 2624, CI-2639, CI-2064, Cl-2734, CI-2855, CI-2823 and CI-2758 from Nippon Soda, Omnicat 320, Omnicat 430, Omnicat 432, Omnicat 440, Omnicat 445, Omnicat 550, Omnicat 550 BL and Omnicat 650 from IGM Resins, Daicat II from Daicel, UVAC 1591 from Daicel-Cytec, FFC 509 from 3M, BBI-102, BBI-103, BBI-105, BBI-106, BBI-109, BBI -1 10, BBI-201, BBI, 301, BI-105, DPI-105, DPI-106, DPI-109, DPI-201, DTS-102, DTS-103, DTS-105, NDS-103, NDS- 105, NDS-155, NDS-159, NDS-165, TPS-102, TPS-103, TPS-105, TPS-106, TPS-109, TPS- 1000, MDS-103, MDS-105, MDS-109, MDS-205, MPI-103 "MPI-105, MPI-106, MPI-109, DS-100, DS-101, MBZ-101, MBZ-201, MBZ-301, NAI- 100, NAI-101, NAI- 105, NAI-106, NAI- 109, NAI-1002, NAI-1003, NAI-1004, NB-101, NB- 201, NDI-101, NDI-105, NDI-106, NDI- 109, PAI-01, PAI-101, PAI-106, PAI-1001, PI-105, PI-106, PI-109, PYR-100, SI-101, SI-105, SI-106 and SI-109 from Midori Kagaku, Kayacure PCI -204, Kayacure PCI-205, Kayacure PCI-615, Kayacure PCI-625, Kayarad 220 and Kayarad 620, PCI-061 T, PCI-062T, PCI-020T, PCI-022T from Nippon Kayaku, TS-01 and TS -91 from Sanwa Chemical, Deuteron UV 1240 from Deuteron, Tego Photocompound 1465N from Evonik, UV 9380 C-D1 from GE Bayer Silicones, FX 512 from Cytec, Silicolease UV Cata 21 1 from Bluestar Silicones and Irgacure 250 , Irgacure 261, Irgacure 270, Irgacure PAG 103, Irgacure PAG 121, Irgacure PAG 203, Irgacure P AG 290, Irgacure CGI 725, Irgacure CGI 1380, Irgacure CGI 1907 and Irgacure GSID 26-1 from BASF. Photo acid generators are used in combination or as a combination of two or more photo acid generators.

According to a particularly preferred embodiment, the photo acid generator contains a compound whose anions are tetrakis (pentafluorophenyl) borate.

The proportion of (D) in the adhesive is preferably at least 0.1% by weight to at most 10.0% by weight, more preferably 1% by weight to 5.5% by weight, further preferably 1.5 % By weight to 4.0% by weight, further preferably 2.0% by weight to 3.0% by weight.

Matxix polymer (E)

Thermoplastic materials, elastomers and thermoplastic elastomers are suitable as optional matrix polymers as film formers for adhesives according to the invention. In particular, they are selected so that, in combination with the other formulation constituents, they make available adhesives which are advantageous with regard to the production, further processing and handling of latent reactive adhesive films. In this context, processing processes at the adhesive tape manufacturer on the one hand and adhesive tape users on the other hand with regard to technical adhesive properties and with regard to further improving the dimensional stability of the adhesive films with regard to the presentation of the adhesive product and the squeezing behavior in the hot lamination process, to name just a few particularly important requirements.

In an advantageous procedure, thermoplastic materials are used as matrix polymers (E) which differ from the (co) polymer (A) and / or epoxy-containing compounds (B) are. Examples are semi-crystalline polyolefins and ethylene-vinyl acetate copolymers (EVA). Preferred polyolefins are prepared from ethylene, propylene, butylene and / or hexylene, it being possible in each case for the pure monomers to be polymerized or for mixtures of the monomers mentioned to be copolymerized. The polymerization process and the selection of the monomers allow the physical and mechanical properties of the polymer to be controlled, such as the softening temperature and / or special mechanical properties.

Elastomers can be used very advantageously as matrix polymers (E). For example, rubber or synthetic rubber may be mentioned as the starting material for the adhesive. There are many possible variations here, be it for rubbers from the group of natural rubbers or synthetic rubbers or be it from any blend of natural rubbers and / or synthetic rubbers, the natural rubber or natural rubbers basically being of all available qualities such as crepe, RSS -, ADS, TSR or CV types, depending on the required level of purity and viscosity, and the synthetic rubber or synthetic rubbers from the group of randomly copolymerized styrene-butadiene rubbers (SBR), butadiene rubbers (BR), the synthetic polyisoprenes (IR), butyl rubbers (IIR), halogenated butyl rubbers (XI IR), acrylate rubbers (ACM), EPDM, polybutylenes or polyisobutylenes can be selected. Elastomers can also be (partially) hydrogenated.

Nitrile rubbers, in particular hot-polymerized ones, and those with an acrylonitrile content between 15% and 50%, preferably between 30% and 45% and a Mooney viscosity (ML 1 +4, 100 ° C.) between 30 and 110 are very advantageous. preferably between 60 and 90.

Also very advantageous are poly (meth) acrylates which are composed of the (co) monomers (b), (c) and / or (d) described above and have a weight-average molar mass of typically at least 100,000 g / mol and typically at most 5 000,000 g / mol, in particular of at least 250,000 g / mol and at most 2,000,000 g / mol. The glass transition temperature of these poly (meth) acrylates can in particular be below 25 ° C or even below 0 ° C and in particular below -25 ° C. In this way, pressure-sensitive reactive adhesive systems are accessible.

Also advantageous are thermoplastic elastomers and in particular block, star and / or graft copolymers with a molecular weight Mw (weight average) of 300,000 g / mol or less, preferably 200,000 g / mol or less. Smaller molecular weights are preferred because of their better processability. The molar mass should not be less than 50,000 g / mol. Specific examples are styrene-butadiene block copolymers (SBS), styrene-isoprene block copolymers (SIS), styrene (isoprene / butadiene) block copolymers (SIBS) and (partially) hydrogenated variants such as styrene (ethylene / butylene) block copolymers ( SEBS), styrene (ethylene / propylene) block copolymers (SEPS, SEEPS), styrene (butylene / butyl) block copolymers (SBBS), styrene iso-butylene block copolymers (SiBS) and polymethyl methacrylate-polyacrylate block copolymers. These block copolymers can be used as a linear or multi-arm structure, as a diblock copolymer, triblock copolymer or multiblock copolymer and as mixtures of different types.

Further advantageous examples of thermoplastic elastomers are thermoplastic polyurethanes (TPU). Polyurethanes are chemically and / or physically cross-linked polycondensates, which are typically made up of polyols and isocyanates and contain soft and hard segments. The soft segments consist, for example, of polyesters, polyethers, polycarbonates, in the sense of this invention preferably aliphatic in nature, and polyisocyanate hard segments. Depending on the type and use ratio of the individual components, materials are available which can be used advantageously for the purposes of this invention. Raw materials that are available to the formulator for this are mentioned, for example, in EP 894 841 B1 and EP 1 308 492 B1. Semicrystalline (partially crystalline) thermoplastic polyurethanes are particularly preferably used.

Furthermore, polyolefin-based thermoplastic elastomers, polyether ester elastomers for matrix polymers (E) can be used. Suitable saturated thermoplastic polymers can also advantageously be selected from the group of polyolefins (for example ethylene-vinyl acetate copolymers (EVA)), polyethers, copolyethers, polyesters, copolyesters, polyamides, copolyamides, polyacrylic acid esters, acrylic acid esters - Copolymers, the polymethacrylic acid ester, the methacrylic acid ester copolymer and chemically or physically crosslinked substances of the aforementioned compounds. In addition, blends of various thermoplastic polymers, in particular from the above classes of compounds, can also be used. Semicrystalline (partially crystalline) thermoplastic polymers are particularly preferably used.

Preferred examples are - in particular semicrystalline - polyolefins. Preferred polyolefins are prepared from ethylene, propylene, butylene and / or hexylene, it being possible in each case for the pure monomers to be polymerized or for mixtures of the monomers mentioned to be copolymerized. The polymerization process and the choice of monomers allow the physical and mechanical properties of the Polymers control such as the softening temperature and / or special mechanical properties

Thermoplastic elastomers can preferably be used as thermoplastic polymers, either alone or in combination with one or more thermoplastic polymers from the abovementioned compound classes. Saturated semicrystalline thermoplastic elastomers are particularly preferably used.

Thermoplastic polymers with softening temperatures below 100 ° C. are particularly preferred. In this context, the term softening point stands for the temperature at which the thermoplastic granulate sticks to itself. If these are semicrystalline thermoplastic polymers, then it advantageously has a glass transition temperature of at most 25 ° C., in addition to its softening temperature (in particular as characterized above) (which is related to the melting of the crystallites).

In a preferred embodiment according to the invention, a thermoplastic polyurethane without C-C multiple bonds is used. The thermoplastic polyurethane preferably has a softening temperature of less than 100 ° C., in particular less than 80 ° C.

In a further preferred embodiment according to the invention, a mixture of two or more saturated thermoplastic polyurethanes is used. The mixture of the thermoplastic polyurethanes preferably has a softening temperature of less than 100 ° C., in particular less than 80 ° C.

The proportion of (E) in the adhesive, if present, is preferably at least 2.0% by weight to at most 94.5% by weight, more preferably 25.0% by weight to 92.5% by weight , further preferably 50.0% by weight to 91.5% by weight, further preferably 75.0% by weight to 90.5% by weight, most preferably 80.0 to 90.0% by weight .

Additives (F)

The adhesive of the present invention may further contain at least one additive. Particularly suitable additives are described below. Further constituents can optionally be added to the adhesives according to the invention which adjust the properties of the adhesives, in particular as a pressure sensitive adhesive, adhesive, sealing or sealing compound, as desired. In this context, adhesive resins (F1) are preferably up to 60% by weight, particularly preferably up to 25% by weight, based on the low-viscosity reactive resins (F2), preferably up to 15% by weight, based on the adhesive and other additives (F3) preferably up to 50% by weight, particularly preferably up to 25% by weight, very particularly preferably up to 10% by weight, based on the adhesive.

(F1) adhesive resins

The adhesive according to the invention optionally contains one or more types of an adhesive resin, advantageously those which are compatible with the (co) polymer (A) and / or the epoxy-containing compound (B) and / or the matrix polymer (E).

It is advantageous if this adhesive resin has an adhesive resin softening temperature (ASTM E28) of greater than 25 ° C., in particular greater than 80 ° C.

Partially or completely hydrogenated or disproportionated resins based on rosin and rosin derivatives, indene-coumarone resins, terpene-phenolic resins, phenolic resins, hydrogenated polymers of dicyclopentadiene, partially, selectively or fully hydrogenated hydrocarbon resins can be used as adhesive resins (F1) in the adhesive, for example Based on C5, C5 / C9 or C9 monomer streams, polyterpene resins based on a-pinene and / or β-pinene and / or d-limonene, hydrogenated polymers of preferably pure C8 and C9 aromatics are used. The aforementioned adhesive resins can be used both alone and in a mixture.

In order to ensure high aging and UV stability, hydrogenated resins with a degree of hydrogenation of at least 90%, preferably of at least 95%, are preferred.

The person skilled in the art selects suitable adhesive resins in accordance with known procedures from the field of pressure-sensitive adhesives for resin / polymer compatibility. In particular, he sees the concept of selection via cloud points using DACP (diacetone alcohol cloud point) and MMAP (mixed methylcylohexane aniline point). The DACP value and the MMAP value each indicate the solubility in a specific solvent mixture. For the definition and determination of the DACP and MMAP value, see C. Donker, PSTC Annual Technical Proceedings, pp. 149-164, May 2001. (F2) low molecular weight reactive resins

Optionally but advantageously, low molecular weight reactive resins can be used which are different from the epoxy-containing compound (B). They preferably have a softening temperature (in particular glass transition temperature) below room temperature. Their weight average molecular weight is preferably less than 5000 g / mol, more preferably less than 1000 g / mol. They are preferably used in a proportion of at most 25% by weight in the adhesive, very preferably of at most 10% by weight. These low-viscosity reactive resins are, in particular, cyclic ethers, that is to say compounds which carry at least one oxirane group, or oxetanes. They can be aromatic or, in particular, aliphatic or cycloaliphatic in nature. Reactive resins that can be used can be monofunctional, difunctional, trifunctional, tetrafunctional or higher functional up to polyfunctional, the functionality relating to the cyclic ether group.

Examples, without wishing to be limited, are 3,4-epoxycyclohexylmethyl-3 ', 4'-epoxycyclohexane carboxylate (EEC) and derivatives, dicyclopendadiene dioxide and derivatives, 3-ethyl-3-oxetanemethanol and derivatives, bis - [(3,4- epoxycyclohexyl) methyl] adipate and derivatives, vinylcyclohexyl dioxide and derivatives, 1,4-cyclohexanedimethanol-bis- (3,4-epoxycyclohexane carboxylate) and derivatives, bis- [1-ethyl (3-oxetanyl) methyl) ether and derivatives, 2- (7-Oxabicyclospiro (1, 3-dioxan-5,3 '- (7-oxabicyclo [4.1 .0] -heptane)), 1, 4-bis ((2,3-epoxypropoxy) methyl) cyclohexane (Cyclo) aliphatic epoxides preferred.

Reactive resins can be used in their monomeric or also dimeric, trimeric, etc. up to their oligomeric form, provided the weight-average molecular weight does not reach or exceed 5,000 g / mol.

Since these reactive resins are typically of low viscosity, they run the risk that an excessive proportion of them in an adhesive leads to an excessive tendency to squeeze. The lowest possible proportion in the adhesive is therefore preferably used at most 25% by weight, very preferably at most 10% by weight. Up to 50% by weight can only be used if the proportion of (co) polymer (A) is at least 50% by weight and the sum of the proportion of (co) monomers (a) and optionally (b ) in the (co) polymer (A) is at least 50% by weight. Mixtures of reactive resins with one another but also with other co-reactive compounds such as alcohols (monofunctional or multifunctional) or vinyl ethers (monofunctional or multifunctional) are also possible.

Alcohols such as monooies, diols, triols or higher-functional polyols are particularly suitable as co-reactive compounds.

Silane coupling agents can also advantageously be used as coupling agents. Compounds of the general form RR ' _a R " _b SiX ₍ 3- _{ab) are} used in particular as silane coupling agents, R, R' and R" being selected independently of one another and in each case one hydrogen atom bonded to the Si atom or one bonded to the Si atom Denote atomically bound organic functionalized radical, X denotes a hydrolyzable group, a and b are each 0 or 1, and where R, R 'and R "or two representatives of this group can also be identical.

Compounds in which, in the presence of several hydrolyzable groups X, are not identical but differ from one another can also be used as adhesion promoters [according to the formula RR ' _a R " _b SiXX' _c X" _d , with X, X ', X "as independently selected hydrolyzable groups (of which two may be identical), c and d are each 0 or 1, with the proviso that a + b + c + d = 2].

Alkoxy groups in particular are used as hydrolyzable groups, so that in particular alkoxysilanes are used as adhesion promoters. The alkoxy groups of a silane molecule are preferably the same, but in principle they can also be selected differently.

For example, methoxy groups and / or ethoxy groups are selected as alkoxy groups. Methoxy groups are more reactive than ethoxy groups. Methoxy groups can therefore have a better adhesion-promoting effect due to faster reaction with the substrate surfaces and the amount used can therefore be reduced if necessary. Ethoxy groups, on the other hand, have the advantage that, owing to the lower reactivity, they have a smaller (possibly negative) influence on the processing time and / or the shelf life of the adhesive film, in particular also with regard to the desired moisture-heat stability.

Trialkoxisilanes R-S1X ₃ are preferably used as adhesion promoters. Examples of trialkoxysilanes suitable according to the invention are Trimethoxysilanes - such as N- (2-aminoethyl) -3-aminopropyl-trimethoxysilane, N-cyclohexyl-3-aminopropyl-trimethoxysilane, 3-aminopropyl-trimethoxysilane, 3-ureidopropyl-trimethoxysilane, vinyltrimethoxysilane, 3-glycidoxysiloxyl trimethyl - trimethoxysilane, methacryloxymethyl-trimethoxysilane, N-methyl- [3-

(T rimethoxysilyl) propyl] carbamate, N-T rimethoxysilylmethyl-O-methyl carbamate, T ris- [3-

(trimethoxysilyl) propyl] isocyanurate, 3-glycidoxypropyltrimethoxysilane,

Methyltrimethoxysilane, isooctyltrimethoxysilane, hexadecyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyl-trimethoxysilane trimethoxysilane, bis- [3- (trimethoxysilyl) propyl] amine, 3-isocyanatopropyl-trimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyl trimethoxysilane; 3-methacryloxypropyl-trimethoxysilane, 3-methacrylamidopropyl-trimethoxysilane, p-styryltrimethoxysila, 3-acryloxypropyl-trimethoxysilane, N- (vinylbenzyl) -2-aminoethyl-3-aminopropyltrimethoxysilane hydrochlridetriethoxysilyl-like-N-aminoxysilyl-like-N-cyclin-3-aminoxysilane-such as N-cyclinoxysilane triethoxysilane, 3-ureidopropyl-triethoxysilane, 3- (2-aminomethylamino) propyl-triethoxysilane,

Vinyl triethoxysilane, 3-glycidoxypropyl-triethoxysilane, methyltriethoxysilane, octyltriethoxysilane, isooctyltriethoxysilane, phenyltriethoxysilane, 1, 2-bis (triethoxysilane) ethane, 3-octanonylthio-1-propylilane; 3-aminopropyl-triethoxysilane, bis- [3- (triethoxysilyl) propyl] amine, 3-isocyanatopropyl-triethoxysilane, 2- (3,4-epoxycyclohexyl) ethyl-triethoxysilane, 3-

Methacryloxypropyl-triethoxysilane, 3-methacrylamidopropyl-triethoxysilane, 3-triethoxysilyl-N- (1, 3-dimethylbutadiene) propylamide -, Triacetoxysilane - such as vinyltriacetoxysilane, 3-methacryloxypropyl-triacetoxysilane, Triacetoxyethylsilane -, mixed trialkoxysilanes - such as 3- methacrylamidopropyl-methoxy- diethoxysilane, 3-methacrylic amidopropyl dimethoxy ethoxysilane

Examples of dialkoxysilanes suitable according to the invention are

 Dimethoxysilanes - such as N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, vinyldimethoxymethylsilane, (methacryloxymethyl) methyldimethoxysilane,

Methacryloxymethyl-methyl-dimethoxysilane, 3-methacryloxypropyl-methyldimethoxysilane, dimethyldimethoxysilane, (cyclohexyl) methyldimethoxysilane, dicyclopentyl-dimethoxysilane, 3-glycidoxypropyl-methyldimethoxysilane, 3-mercethropoxysilane

Diethoxysilanes - such as dimethyldiethoxysilane, gamma-aminopropyl-methyl-diethoxysilane; 3-glycidoxypropyl-methyldiethoxysilane, 3-methacryloxypropyl-methyldiethoxysilane

An example of a monooxysilane is trimethyloxysilane. The amount of adhesion promoter added can basically be selected in a wide range, depending on the desired properties of the product and taking into account the selected raw materials of the adhesive film. However, it has proven to be very advantageous according to the invention if the amount of the adhesion promoter used, based on the adhesive used, is particularly preferably in the range from 0.5 to 20% by weight, preferably in the range from 1 to 10% by weight from 1.5 to 5% by weight, very particularly preferably in the range from 2.5 to 3.5% by weight.

 Very high amounts of adhesion promoters used can have a strongly softening effect, so that - especially with regard to sufficiently stable films - it can be advantageous to choose the amount of adhesion promoter as small as possible, so that on the one hand the desired positive influence on the moisture Heat resistance is sufficiently large, on the other hand, the properties of the adhesive film in terms of its dimensional stability and stability are not adversely affected.

As additional optional components (F), additives (F3), such as anti-aging agents, such as antiozonants, antioxidants, light stabilizers, can be added as additives to the adhesives.

The following may be mentioned as possible optional additives (F3) of the adhesive:

 • primary antioxidants such as sterically hindered phenols

 • secondary antioxidants such as phosphites or thioethers

 • Process stabilizers such as C radical scavengers

 • Light stabilizers such as UV absorbers or sterically hindered amines

 Processing aids such as rheologically active additives (e.g. thickeners)

 • Network additives

 • blowing agents such as chemical foaming agents and / or expanded or expandable microballoons and / or hollow spheres such as hollow glass spheres

 • Adhesion promoter

 • Compatibility mediators / compatibilizers

 • Colorants / pigments

 • Fillers / functionalized fillers

This list is not to be considered as restrictive or exhaustive.

The adhesive advantageously also contains one or more plasticizers. Examples of these are plasticizers based on aliphatic or cycloaliphatic alkyl esters. The esters are preferably aliphatic or cycloaliphatic carboxylic acids, especially dicarboxylic acid. However, phosphoric acid esters (phosphates) can also be used. Among the aliphatic carboxylic acid esters, alkyl or cycloalkyl adipates such as, in particular, di- (2-ethylhexyl) adipate, diisononyl adipate, diisodecyl adipate, ditridecyl adipate and dioctyl adipate may be mentioned as examples. Further examples are alkyl and cycloalkyl sebacates such as, in particular, di (2-ethylhexyl) sebacate and alkyl and cycloalkylazylates such as in particular di (2-ethylhexyl) azelate. Aliphatic or cycloaliphatic cyclohexyldicarboxylic acid diesters, as described, for example, in WO 201 1/009672 A1, are particularly preferably used, in particular 1,2-diisobutylcyclohexanedicarboxylic acid ester, 1,2-di- (2-ethylhexyl) cyclohexanedicarboxylic acid ester or 1,2- Diisononylcyclohexanedicarboxylic acid ester (also referred to as "DINCH"). Selected representatives of this group are available from BASF SE, for example. As with the selection of adhesive resins, the choice of optionally usable plasticizers is based on compatibility with other constituents of the adhesive, in particular with (co) polymers (A) and / or epoxy-containing compounds (B) and / or, if available, matrix polymers ( E) respected.

The additives are not mandatory; one advantage of the adhesive according to the invention is that it has its advantageous properties, even without additional additives being added individually or in any combination. Nevertheless, it can be advantageous and desirable in detail to adjust certain additional properties of the adhesive, in particular the usual adhesives, pressure-sensitive adhesives, sealants or sealants, by adding additives.

For example, the transparency of the mass and its color can be influenced. Some formulations are optically clear, others are opaque, others are colored, black, white or gray.

Also among the optional additives, preference is given to those which, before the initiation of the curing reaction, undergo essentially no or in particular no reaction with glycidyl or epoxy functionalities or which neither initiate nor catalyze the reactions of the glycidyl or epoxy functionalities, or those which where the reaction with glycidyl or epoxy functionalities is otherwise prevented.

In combination with optionally usable comonomers (d) based on silane, if such are used, or alternatively, other silanes which are not incorporated by polymerization into the functionalized (co) polymers (A) according to the invention can be used as adhesion promoters. Examples of silanes which can be used in the context of this invention are, without wishing to be restricted, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, iso-butyl trimethoxysilane, iso-butyl triethoxysilane, Octyltrimethoxysilane, octyltriethoxysilane, isooctyltrimethoxysilane, iso-octyltriethoxysilane, hexadecyl, hexadecyl, octadecylmethyldimethoxysilane,

Phenyltrimethoxysilane, phenyltriethoxysilane, cyclohexylmethyldimethoxysilane,

Dicyclopentyldimethoxysilane.

An example of silyl-functionalized oligomers or polymers that can be used according to the invention is polyethylene glycol, which is linked to a trimethoxysilane group.

Further examples of usable silanes which carry at least one functionalization are vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri (2-methoxyethoxy) silane,

Vinyltriisopropoxysilane, vinyldimethoxymethylsilane, vinyltriacetoxysilane, 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, 3-glycidyloxypropyldoxaniloxane

Methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropyltriethoxysilane, 3-

Methacryloyloxypropyltriisopropoxysilane, 3-methacryloyloxypropyldimethoxymethylsilane, 3-methacryloyloxypropyldiethoxymethylsilane, 3-chloropropyltrimethoxysilane, 3-

Chloropropyltriethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 2-hydroxy-4- (3-triethoxysilylpropoxy) benzophenone, 4- (3'-chlorodimethylsilylpropoxy) benzophenone.

Examples of optional crosslinkers are latent reactive diamines or multifunctional amines, dicarboxylic acids or multifunctional carboxylic acids, difunctional acid anhydrides or multifunctional acid anhydrides, primary dithiols or multifunctional primary thiols. Particularly advantageous with regard to latency are those reactants which are solid at room temperature and not soluble in the polymer according to the invention or in a mixture containing this polymer in the non-softened state but soluble in the softened state or both melts are miscible with one another.

Initiators / hardeners are also conceivable, which are encapsulated and / or blocked and are distributed and / or deblocked in the film matrix under the influence of heat and can then lead to a reaction. If filler particles are used, their structure can preferably be spherical, rod-shaped or platelet-shaped. Separated particles, often also referred to as primary particles, are just as much in accordance with the invention as aggregates formed from several primary particles. Such systems often show a fractal superstructure. If the particles are formed from crystallites, the primary particle shape depends on the type of crystal lattice. Platelet-shaped systems can also be in the form of layer stacks. If fillers are used, then typically up to 50% by weight.

In an advantageous embodiment of this invention, one type of filler is present in the adhesive substantially in the form of singular spherical particles, i.e. preferably in a proportion of more than 95%, more preferably more than 98%, most preferably more than 99%. The particle diameters then have values of less than 500 nm, preferably less than 100 nm, very preferably less than 25 nm. In a further advantageous embodiment of this invention, the at least one functionalized filler type in the adhesive is essentially in the form of singular platelet-shaped particles. The layer thickness of such platelets then has values of preferably less than 10 nm and a largest diameter of preferably less than 1000 nm. In a further advantageous embodiment of this invention, the at least one type of filler is present in the adhesive essentially in the form of singular rod-shaped particles. In this case, these rods have a diameter of less than 100 nm and a length of less than 15 pm. The rods can also be curved and / or flexible. Furthermore, in the sense of this invention it is advantageously possible for the at least one filler type to be present in the adhesive in the form of primary particle aggregates. These aggregates have a gyration radius (to be understood analogously to the term “gyration radius” known from polymers) of less than 1000 nm, preferably less than 250 nm. For the purposes of this invention, filler particles are particularly preferably used whose spatial extent in at least one direction is less than 250 nm, preferably less than 100 nm, very preferably less than 50 nm. It is also possible for the purposes of this invention to use combinations of the above use the filler types mentioned.

Typical and further advantageous classes of compounds for fillers according to the invention are semi-metal oxides of an inorganic nature, minerals based on silicate, in particular clay minerals and clays. The amorphous or crystalline metal oxides which can be used according to the invention include, in particular, silicon dioxide. The person skilled in the art is familiar with further systems which can also be used according to the invention. Carbonates, sulfates, hydroxides, phosphates and hydrogen phosphates are conceivable. The clay minerals and clays that can be used according to the invention include, in particular, silicate systems such as serpentines, kaolins, talc, pyrophyllite, Smectites such as in particular montmorillonite, vermiculite, hats, mica, brittle mica, chlorite, sepiolite and palygorskite. Furthermore, synthetic clay minerals such as hectorites and their related systems such. B. Laponite® from Laporte and Fluorhectorite and their related systems such. B. Somasif® from Co-Op can be used according to the invention.

Filler particles can be functionalized on their surface, hydrophobic or hydrophilic. Functionalization by means of compounds having glycidyl and / or aliphatic epoxy groups, which can participate in the curing reaction, is particularly advantageous.

The fillers are not mandatory, the adhesive also works without them being added individually or in any combination. Also selected from the optional fillers are those which, prior to the initiation of the curing process, undergo essentially no or in particular no reaction with glycidyl or epoxy functionalities or initiate or catalyze reactions of the glycidyl or epoxy functionalities or the reaction with glycidyl or Epoxy functionalities are otherwise prevented.

The adhesive films according to the invention have proven to be excellently pre-laminatable and can be activated in the hot pressing step to form the final adhesive strength, that is to say they include the ability for a chemical reaction, in particular for a rapid crosslinking and / or curing reaction, after appropriate activation. The activation takes place in particular thermally, that is, by supplying heat. Basically, other activation methods - such as induction, by microwaves, by irradiation with UV radiation, laser treatment, plasma treatment - are also known for latent reactive adhesive tapes. For the purposes of the present invention, however, the activation takes place by supplying thermal energy, and the further activation methods can be used in particular and optionally additionally (additively).

During the supply of heat, the adhesive melts and can excellently wet the substrate surfaces to be bonded, and the crosslinking or curing reaction leads to an increase in the cohesion of the adhesive.

As a result of the reactive bonding, the adhesive films according to the invention are thus able to generate high bond strengths to the substrate substrates to which they are bonded. The bond strengths can be, for example, orders of magnitude assume that they exceed the usual pressure sensitive adhesives (typically <1.0 MPa in the push-out test) by a factor of 10 and more.

The adhesives used in accordance with the invention and the corresponding adhesive films are latently reactive. In the context of this invention, adhesive systems which can be activated and which can be stably stored over long periods of time without activation are referred to as latent-reactive. Latent-reactive adhesive films are, in particular, those which do not or only over a period of time in a normal climate (23 ° C [296.15 K]; 50% rh) and advantageously at elevated storage temperatures (in particular up to 40 ° C [316.15 K]) harden for several weeks, preferably months, and are therefore stable in storage, but which can be activated at higher temperatures and harden and / or crosslink. The latent reactivity has the advantage that these adhesive films can be stored, transported and further processed (for example, made-up) in a normal climate and advantageously in particular at elevated temperatures up to 40 ° C. before they are used at the bond point and cured.

The adhesives should not change significantly during the storage period, so that the adhesive properties of an adhesive system freshly used for manufacturing after manufacturing and an adhesive system used after longer storage for the otherwise comparable bonding do not differ significantly, but at least still correspond to the requirement profile (push Out> 1.5 MPa), preferably at least 50%, particularly preferably at least 75%, very particularly preferably at least 90% of the performance of the non-stored adhesive film.

The compositions according to the invention are distinguished in that, on the one hand, they are latently reactive and, on the other hand, they can be quickly hardened at elevated temperature.

In a preferred embodiment of the invention, at least one adhesive-reinforcing additive - also referred to as an adhesion promoter - is added to the adhesive. Adhesion promoters are substances that improve the adhesive force of the adhesive film on the substrate to be bonded. This can be done in particular by increasing the wettability of the substrate surfaces and / or by forming chemical bonds between the substrate surface and the adhesive or components of the adhesive. Advantageous adhesion promoters are described above under (F). Adhesive films

The adhesive according to the invention is an adhesive film or is - in addition to one or more further layers - part of an adhesive film. The invention thus also includes adhesive films made from the adhesive according to the invention and adhesive films comprising a layer made from the adhesive according to the invention.

The adhesive films according to the invention can be constructed in one layer - that is to say solely from the layer of the underlying adhesive - or else in multiple layers, for example provided with a reinforcement or carrier layer. Single-layer systems, so-called transfer adhesive tapes, are advantageous.

In principle, all layers of the materials suitable for the person skilled in the art can be used as the carrier, depending on the desired properties of the product and resistance to thermal activation. For example, backing materials such as textile materials, fabrics, nonwovens, papers, plastic films, such as mono or biaxially oriented, optionally oriented polyolefins, polyvinyl chloride films (PVC), polypropylene films, polyethylene (PE) films, such as HDPE, LDPE ), Polyethylene terephthalate films (PET), polylactide films and foams and fabrics are used. Backing materials can have high or low extensibility and / or flexibility and can be selected, for example, to be tear-resistant or easily tearable. In principle, suitable - in particular cohesive - rubber films or adhesive layers, such as, for example, pressure-sensitive adhesives or activatable adhesives, can also be used as carriers, which have a corresponding inherent stability and meet the requirements for the bonding conditions of the adhesive films.

The adhesive films can be covered on one or both sides with a protective material, so-called "liners". Liners serve as temporary protection and the handling of the adhesive tape is removed again for application. For the purposes of the present invention, such liners are regarded as procedural aids, but not as an actual part of the adhesive films according to the invention. Liners can be paper or foils, which are equipped at least on the side facing the adhesive film according to the invention with a suitable release agent known to the person skilled in the art. It can also be paper or foils with a slightly tacky finish (so-called tackyliner). Laminate adhesive tapes, that is to say adhesive tapes composed of a plurality of adhesive layers arranged one on top of the other, can also be offered according to the invention. Laminates are advantageous, for example, if thicker strapless adhesive tapes are to be produced by simple processes, since it is generally easier to produce thin adhesive layers and then laminate them together than to coat adhesive layers of the resulting total thickness directly to form a uniform, homogeneous product.

Adhesive layers, transfer adhesive tapes and laminate adhesive tapes according to the invention can be designed from very thin designs - in the range of a few micrometers - to very thick layers - in the range of several centimeters. Correspondingly, multi-layer adhesive tapes - in particular also those which comprise further layers in addition to the adhesive layers - can vary in thickness, given by the respective thickness of the adhesive layers - as described above - and the further layers used, such as carrier layers, pressure-sensitive adhesives, functional (e.g. thermally and / or electrically conductive or insulating) layers, primer layers and the like.

Typical layer thicknesses for single-layer adhesive films according to the invention are in the range from 1 to 500 μm, for example 5, 20, 25, 50, 75, 100, 125, 150, 175 or 200 μm.

The adhesive films according to the invention are self-supporting and thus independent products, that is to say they can be stored, transported and applied without further ado. This distinguishes them essentially from "adhesive films" made of liquid adhesives, i.e. adhesive layers that only exist after application to the substrate to be bonded and are solidified there - within the scope of their application during use - but are not removed from the substrate again as an independent product. For example, adhesive films according to the invention can be wound up into a roll or offered as sections, die-cuts or so-called die-cuts. Accordingly, any cuts and die-cuts of adhesive films according to the invention are the subject of the invention. Another advantage of the adhesive films according to the invention over film-like applications from liquid adhesives is that they have an intrinsic dimensional stability during the application and curing reaction and not, like film-like applications from liquid adhesives, need to be fixed during the curing reaction.

The effective bonding by means of the adhesive films with their activation means an interaction of temperature, time (cycle time), the lower one of the parameters is selected, the higher can or must another parameter be selected. With higher ones Temperatures can be achieved with shorter cycle times. If the cycle time can be set longer, it is possible to work at a lower temperature.

In this context, the pressing pressure primarily represents a process parameter and is dependent on the raw materials used in the formulation in combination with the cycle time. For example, an increase in pressure can favor the flow onto the substrates and the wetting of the substrates in formulations with increased melt viscosity in combination with short cycle times. In the case of formulations with a lower melt viscosity, in particular in combination with longer cycle times, a lower pressure can be advantageous in order to prevent undesired squeezing (so-called oozing) of the adhesive from the adhesive joint. For the advantageous and inventive formulations determined here, it was possible, for example, to advantageously work with a pressing pressure of 10 bar, but the invention is not restricted to this pressing pressure.

In particular, the contact time during the activation of the adhesive film (the activation time) can be considerably reduced by varying the other parameters within the parameter limits still available, which are given by the resistance of the substrates to be bonded.

Basically, the maximum permitted temperature is determined by the substrates to be bonded. For many of the intended applications (such as the bonding of plastics and / or anodized substrates) the temperature should not be higher than 200 ° C in order not to damage the substrates. The basic principle here is that the higher the selected temperature, the shorter the cycle time, in order to use the substrates with minimal damaging heat. According to the invention it has been possible to reduce the cycle time to less than 10 s at a temperature of 200 ° C. and to 10 s at 190 ° C. (10 bar per pressure). At temperatures below 170 ° C, however, maximum cycle times of up to one minute, advantageously up to 30s, can be acceptable. Generally, the shortest possible cycle time at a maximum possible temperature, depending on the sensitivity of the substrates to be joined, is advantageous in order to increase productivity in the processing process.

The adhesive films according to the invention can be stored well without losing their positive properties as adhesive films. The adhesives should not change significantly during the storage period, so that the adhesive properties of a freshly used adhesive system after manufacture and one after prolonged storage, advantageously in particular at elevated storage temperatures of 40 ° C., for the other Do not significantly differentiate comparable adhesive system applied, preferably at least still meet the requirements profile (push-out> 1.5 MPa), more preferably at least 50%, particularly preferably at least 75%, very particularly preferably at least 90% of the performance of the have not stored adhesive film.

The resistance to moisture and heat can be further optimized by adding one or more adhesion promoters to the adhesive used to produce the latent-reactive adhesive film according to the invention. Substances which improve the adhesion of the adhesive film to the substrate surface can be used as an adhesion promoter.

The so-called push-out test is regarded in particular as a quantitative criterion for the adhesive properties of an adhesive film. For the push-out test, a disc-shaped substrate is glued to a second, frame-shaped substrate with an adhesive film sample and then the force that has to be applied to separate the two substrates from one another is determined (compare the further details in the experimental part; Test method A).

The adhesive films according to the invention preferably have good bond strength. The result of the push-out test is used to quantify the bond strength. The adhesive films according to the invention preferably have a fresh sample (freshly coated adhesive film after drying for 30 min at 70 ° C. in a suitable circulating air drying cabinet and subsequent conditioning for 24 hours in a standard climate (23 ° C./50% RH) in the push-out test (force measurement for Solution of an adhesive composite made of a polycarbonate pane (Makroion 099) with a frame made of anodized aluminum (E6EV1) by means of a layer of the adhesive film to be examined with a thickness of 100 pm with an effective bonding area of 282 mm ² [compare also tests A and B] Push-out value of at least 1.5 MPa, preferably of at least 2.5 MPa, very particularly preferably of at least 3.5 MPa or even higher, and preferably in after bonding under the following bonding conditions I, more preferably also after the following bonding conditions II, and even more preferably also under the following bonding conditions III:

I. pre-lamination 70 ° C, 15 s; Final gluing (pressing conditions) 190 ° C, 10 s; 10 bar; Conditioning the adhesive bond for 24 h at 23 ° C / 50% RH [RH stands for relative air humidity]; Testing at 23 ° C, 50% RH II. Pre-lamination 70 ° C, 15 s; Final gluing (pressing conditions) 180 ° C, 12 s; 10 bar; Conditioning the adhesive bond for 24 h at 23 ° C / 50% rh; Testing at 23 ° C, 50% RH

 III. Pre-lamination 70 ° C, 15 s; Final gluing (pressing conditions) 170 ° C, 30 s; 10 bar; Conditioning the adhesive bond for 24 h at 23 ° C / 50% RH; Testing at 23 ° C, 50% RH

 These pressing conditions depend on the radical generator used and are in no way to be understood as restrictive. Shorter and / or longer pressing times and / or lower and / or higher pressing temperatures can also be advantageous.

In a further very preferred manner, the adhesive films according to the invention also have good moisture and heat resistance. The push-out test can also be used to quantify the moisture-heat resistance, namely after defined storage (72 h at 85 ° C. and 85% RH, F) of the adhesive composite to be examined, produced by means of the adhesive film according to the invention. The details of this test are described in detail in the experimental section.

The adhesive films according to the invention advantageously have a push-out test even after storage under moist and warm conditions (force measurement to release an adhesive bond from a polycarbonate pane (Macroion 099) with a frame made of anodized aluminum (E6EV1) by means of a layer of the adhesive film to be examined of 100 pm Thickness with an effective bond area of 282 mm ^{2 has} a push-out value of at least 1.5 MPa, preferably of at least 2.5 MPa, very particularly preferably of at least 3.5 MPa or even higher, and preferably in all three Cases after gluing under the aforementioned gluing conditions I, II and III.

 These pressing conditions depend on the radical generator used and are in no way to be understood as restrictive. Shorter and / or longer pressing times and / or lower and / or higher pressing temperatures can also be advantageous.

In addition - in combination with the aforementioned minimum values - the bond strength - in the sense of the aforementioned push-out force value - of the adhesive bonded assembly stored in the moist heat storage should preferably be more than 50% of the bonded bond bonded not under the heat storage, more preferably the bond strength of the bonded bonded assembly under the moist heat be more than 75% of the non-moist heat-stored adhesive composite, and very preferably the bond strength of the moist-heat-stored adhesive composite should be more than 90% of the non-moist-heat stored adhesive composite or even exceed the value of the non-moist heat-stored composite. Latent-reactive adhesive systems are those adhesives that can be activated and that can be stored in a stable manner over long periods of time without activation. Preferred latent-reactive adhesive films are those which do not or only have one in a normal climate (23 ° C [296.15 K]; 50% rh) and advantageously in particular at higher temperatures (in particular up to 40 ° C [316.15 K]) Cure for several weeks, preferably months, and are therefore stable in storage, but which can be activated - for example at significantly higher temperatures (see also the "Latency" test in the experimental section) and harden and / or crosslink. The latent reactivity has the advantage that these adhesive films can be stored, transported and further processed (for example, assembled) in a normal climate and / or at elevated temperatures, in particular up to 40 ° C., before they are used at the bond point and cured.

The adhesives should advantageously not change significantly during the storage period, so that the adhesive properties of a freshly used adhesive system after manufacture and an adhesive system used after longer storage for the otherwise comparable adhesive system do not differ significantly. The latent reactivity (also called latency in the context of the writing) of the adhesive films can also be quantified using the push-out test.

For the purposes of this document, adhesive films are considered to be latent-reactive in particular if, after at least 3 weeks, preferably at least 4 weeks, at 40 ° C, an adhesive film sample stored in a commercially available, suitable forced-air drying cabinet (drying cabinet is in the standard atmosphere) compared to a sample Incidentally, identical fresh sample in the push-out test (force measurement to solve an adhesive bond from a polycarbonate pane (Makroion 099) with a frame made of anodized aluminum (E6EV1) by means of a layer of the adhesive film to be examined with an effective bonding area of 282 mm ² no more than 25% loss, preferably not more than 15%, particularly preferably not more than 10%, preferably in all three cases after bonding under the aforementioned bonding conditions I, II and III.

 These pressing conditions depend on the radical generator used and are in no way to be understood as restrictive. Shorter and / or longer pressing times and / or lower and / or higher pressing temperatures can also be advantageous.

More preferably, the adhesive films are also resistant to the moist-heat behavior, that is to say, in the push-out test of the adhesive composite, they are preferred for at least 3 weeks even after the adhesive film has been stored for a long time before the composite is produced at least 4 weeks at 40 ° C in a commercially available, suitable circulating air drying cabinet (drying cabinet is in the standard climate)], and after further moist heat storage (72 h at 85 ° C and 85% RH) and subsequent reconditioning in a normal climate (24 h at 23 ° C [ 296.15 K]; 50% rh), of the adhesive bond produced, only permissible deviations from the corresponding values of an adhesive bond made of appropriately stored adhesive films, but without the composite being stored in moist heat.

Moisture-heat resistance, even of long-term adhesive films, is - in accordance with the criteria already mentioned above - once again if the bond strength of the bonded moisture-heated bond is more than 50% of the bonded bond that is not stored under moist heat, considered good moisture-heat resistance if the bond strength of the heat-stored adhesive composite is more than 75% of the non-moist heat-stored adhesive composite, and there is very good moisture-heat resistance if the bond strength of the moisture-heat-stored composite exceeds at least 90% of the value of the sample not stored.

The determination of the bond strength corresponds to the push-out test already mentioned. The adhesive films according to the invention are basically suitable for bonding all substrates, both rigid and flexible materials. The substrates to be bonded can have various configurations, thicknesses and the like. Examples include glass, all kinds of plastics, metal, ceramics, textiles, all kinds of materials, synthetic leather, natural substrates, each with the same material and also with each other.

Experimental part

The adhesive film samples according to the invention and the comparative samples are evaluated using the test methods shown below. The test methods represent the preferred measurement methods for the respective features described above, unless the measurement method was explicitly defined differently there.

Push-out test:

The push-out test enables statements about the bond strength of an adhesive product in the direction of the normal layer. A circular first substrate is provided

(1) (polycarbonate, Macrolon 099, thickness 3 mm) with a diameter of 21 mm, a second substrate

(2) (anodized aluminum, E6EV1, thickness 1.5 mm) - for example square with a side length of 40 mm - with a circular, centrally arranged opening (hole) with a diameter of 9 mm as well as the adhesive film sample to be examined, which is also circular with a diameter of 21 mm was made up (cut or punched).

A test specimen is produced from the aforementioned three components by pre-laminating the adhesive product with the free surface to the substrate (1) in a precisely fitting manner (at 70 ° C. for 15 s). Then the temporary carrier is removed and this composite with the now exposed side of the adhesive product is pre-laminated onto the substrate 2 concentrically (also at 70 ° C. for 15 s), in such a way that the circular recess of the substrate 2 is exactly in the middle above the circular first Substrate 1 is arranged (bonding area thus 282 mm ² ). Care is taken to ensure that the total time of exposure to temperature (70 ° C) in the

Pre-lamination process does not exceed 30 s. The entire composite is then pressed under pressure and temperature, creating the test specimen. The pressing conditions are specified in the evaluation.

After pressing, the test specimens are stored for 24 h at 23 ° C and 50% relative humidity (RH) (standard test climate) (reconditioning).

The test is carried out as follows: A tensile testing machine is equipped with a cylindrical punch (steel, diameter 7 mm) and the test specimen is clamped over a substrate (2) in a holder of the tensile testing machine, so that substrate (1) is only held by the bond and through sufficient pressure can be removed by loosening the bond. The sample is fixed in such a way that bending of the substrate (2), which is possible due to the force during the test, is minimized. By means of the cylindrical stamp through the Hole in the substrate (2) pressed vertically (i.e. parallel to the normal vector of the adhesive product surface) and centrally onto the exposed surface of the adhesive product at a constant speed of 10 mm / s, the tests are carried out in a standard test atmosphere (23 ° C at 50% RH) ) instead of.

The force at which the bonding fails and substrate (1) is detached from substrate (2) is recorded (release of the adhesive bond, recognizable by a sudden drop in force). The force is normalized to the bond area (N / mm ² or MPa). The arithmetic mean of three individual tests is calculated due to the naturally high scatter of the individual results, especially in laboratory samples and due to the adhesion failure that sometimes occurs (failure at the substrate-adhesive film interface).

Moist and heat resistance:

The test specimen preparation and testing is carried out analogously to the push-out test, but the test specimens are stored for 24 h at 23 ° C and 50% relative humidity (RH) (standard test climate) and then upright (on one of the 40 mm Long-side sides of the base plate) are subjected to a moist-heat storage (72 h at 85 ° C and 85% RH) and reconditioned again before testing for 24 h at 23 ° C and 50% RH.

 If the substrate 1 slips off the substrate 2 during the wet-heat storage (or the substrates visibly slide against one another), the sample has failed and there is no sufficient resistance to wet-heat.

 Moist and heat resistance is present if the bond strength after reconditioning is more than 50% of the value before moist heat storage, good if it is more than 75% of the original value and very good moisture and heat resistance if the value is at least 90% of the original value or exceeds it.

DSC:

 Dynamic differential calorimetry (Differential Scanning Calorimetry, DSC) is carried out according to DIN 53765 and DIN 53765: 1994-03. Heating curves run at a heating rate of 10 K / min. The samples are measured in aluminum crucibles with a perforated lid and nitrogen atmosphere. The first heating curve is from -140 ° C to +250 ° C, the second heating curve from -140 ° C to +350 ° C. Both heating curves are evaluated. The enthalpy is evaluated by integrating the reaction peak.

This measurement also serves to determine the glass transition temperatures, the details of which relate to the glass transition temperature value Tg of the measurement method mentioned and the melting point, the details of which relate to the peak maximum value TSP of the melting temperature measurement, and the softening point, the details of which refer to the peak maximum of the decrystallization / peak minimum of the crystallization (crystalline or semi-crystalline systems).

GPC (gel permeation chromatography):

 First, a calibration with poly (styrene) standards was carried out in the separation area of the column. Subsequently, using the known Mark Houwink coefficients a and K, the poly (styrene) calibration was universally converted into a poly (methyl methacrylate) calibration.

 The samples were weighed exactly, mixed with a defined volume of solvent (eluent with approx. 200 ppm (m / V) toluene as internal standard) and dissolved for 24 hours at room temperature. The solutions were then filtered through a 1.0 pm disposable filter and injected with an autosampler.

Eluent: THF / 0.1 vol% trifluoroacetic acid (TFA)

 Guard column: PSS - SDV, 10 pm, ID 8.0 mm x 50 mm

 Columns: PSS - SDV, 10 pm linear one, ID 8.0 mm x 300 mm SN0032906

 Pump: PSS-SECcurity 1260 HPLC pump

 Flow: 0.5 ml / min

Sample concentration: approx. 0.5 g / l

 Injection system: PSS-SECcurity 1260 autosampler ALS

Injection volume: 100 pl

Temperature: 23 ° C

Detector: PSS-SECcurity 1260 RID

The molar masses M _w and M _{n are then} determined.

Raw materials used

 Commercially available products will be used as available in September 2018.

Examined epoxy resin

Comparative Example 1 100% by weight Epikote 828 LVEL

Comparative Example 2 97.5% by weight Epikote 828 LVEL + 2.5% by weight Deuteron UV 1242 Comparative Example 3 95% by weight Epikote 828 LVEL + 5% by weight dicumyl peroxide

Example 1 92.5% by weight Epikote 828 LVEL + 5% by weight dicumyl peroxide + 2.5

 % By weight of Deuteron UV 1242

The Epikote 828 LVEL was homogenized with the other reagents in a suitable screw cap glass on a suitable roller mixer.

Polymerization of the TTA15 homopolymer

100 g of 3,4-epoxycyclohexyl methacrylate (TTA15 - JIANGSU TETRA NEW MATERIAL TECHNOLOGY CO., LTD. (CAS 82428-30-6)) and 298.5 g MEK are weighed into a vacuum-proof standard 2 L glass reactor. The reaction mixture is rendered inert to nitrogen-free with nitrogen and then heated to a product temperature of 70.degree. The polymerization reactor is evacuated at a constant product temperature of 70 ° C to reflux on the cooler. The reaction is carried out isothermally at the product temperature of 70 ° C. When reflux is reached, the reaction is initiated with 2 g of 2,2-azobis (2,4-dimethylvaleronitrile) (CAS 4419-1 1-8) dissolved in 5.8 g of MEK. 1 h, 2 h, 3 h after the first initiator addition, 2 g of 2,2-azobis (2,4-dimethylvaleronitrile), dissolved in 5.8 g of MEK and 100 g of 3,4-epoxycyclohexyl methacrylate, are added to the reaction. After 6 h, 7 h, 0.6 g of di (4-tert-butylcyclohexyl) peroxydicarbonate (CAS 15520-1 1-3), dissolved in 11.4 g MEK, are added. 22 hours after the addition of the first initiator, the reaction is stopped and the polymer solution is cooled to room temperature. The polymer obtained in this way has the following molar mass distribution, measured by means of gel permeation chromatography: Mw = 32375 g / mol, Mn = 13441 g / mol. PDI = 2.4087

Examined epoxy homopolyer

Comparative Example 4 100% by weight TTA15 homopolymer

 Comparative Example 5 97.5% by weight of TTA15 homopolymer + 2.5% by weight of Deuteron UV 1242 Comparative Example 6 95% by weight of TTA15 homopolymer + 5% by weight of dicumyl peroxide

Example 2 92.5% by weight of TTA15 homopolymer + 5% by weight of dicumyl peroxide + 2.5

 % By weight of Deuteron UV 1242

The TTA15 homopolymer solution in MEK was homogenized with the other reagents in a suitable screw cap glass on a suitable roller mixer. The MEK was then removed at room temperature in a suitable manner known to those skilled in the art.

Examined latent reactive adhesive film

The masterbatch is prepared in a suitable solvent kneader in MEK, the solids content of the finished masterbatch is FG = 45% by weight.

 Composition of masterbatch:

 50% by weight of Desmomelt 530

25% by weight Aktisil EM

25% by weight of Heucodur Black 9-100

Example 3

 84.5% by weight of masterbatch (dry matter)

 5% by weight dicumyl peroxide

 5% by weight TTA15 - homopolymer (dry matter)

 3% by weight of 3- (trimethoxysilyl) propyl methacrylate

 2.5% by weight of Deuteron UV 1242

FG = 40% by weight in MEK (solids content, sum of all components minus solvents) All components were homogenized in a suitable screw cap glass on a suitable roller mixer and coated to a dry film thickness of 100 μm using a suitable coating method known to the person skilled in the art and dried in a suitable circulating air drying cabinet at 70 ° C. for 30 minutes.

Comparative Example 7 (Example E1 from DE 10 2016 207 548 A)

Example E1 from DE 10 2016 207 548 A describes a latently reactive adhesive film based on a thermal acid generator (TAG; Thermal Acid Generator). For a latently reactive adhesive film, this state of the art is characterized by an excellent property profile, with very good performance and a very good latency at storage temperatures up to 23 ° C. The disadvantage of this prior art is the significantly reduced latency at elevated storage temperatures of 40 ° C and the use of a high-priced special chemical (TAG).

Examples 1 to 3 represent examples according to the invention, comparative examples 1 to 7 are comparative examples.

Push-out test after storage (example 3)

w = weeks, s = standard deviation Moist heat resistance after storage (example 3)

w = weeks, s = standard deviation

Push-out test after storage (comparative example 7)

w = weeks, d = age, s = standard deviation

 Moist heat resistance after storage (comparative example 7)

w = weeks, d = days, s = standard deviation DSC measurements

DSC measurements were carried out with the examples and comparative examples in order to investigate the influence of the components on the crosslinking behavior (ie the curing of the adhesive film). The results are shown in Figures 1 to 3.

 DSC measurement:

 Measuring device: DSC 204 F1 Phoenix, Netzsch

Crucible: Al crucible, lid perforated manually

 Temperature program: 20 ° C—> -140 ° C; -140 ° C—> 250 ° C (first heating curve)

 (optional) 250 ° C -> -140 ° C; -140 ° C—> 350 ° C (second heating curve)

Temperature rate: 10 K / min (cooled with liquid N ₂ )

 Method / SOP: DSC-01

1 shows the results of the epoxy resin investigated, with comparative examples 1 to 3 and example 1.

In a second heating curve carried out, in contrast to comparative example 2, no postcrosslinking can be observed for example 1. FIG. 2 shows the results of the epoxy homopolymer investigated, with comparative examples 4 to 6 and example 2.

Figure 3 shows the results of the latent reactive adhesive film investigated with Example 3. The curves in the figures are labeled according to the example numbers. The symbols "+" symbolize the places of the values as indicated in the following two tables.

Values in Figure 1:

 AHK = heating curve values in Figure 2:

Values in Figure 3:

In the DSC it is clearly evident that the examples according to the invention show an earlier (ent. Maximum [° C.]) and clearly more defined (harder) reactivity (enthalpy [J / g]) than the reference samples (comparative examples) with the individual components. In addition, the reaction enthalpy (enthalpy [J / g]) of the examples according to the invention is significantly higher than the added reaction enthalpies of the respective individual components (comparative examples), which is evidence of a more complete curing reaction. Furthermore, the T _G “disappears” after the curing reaction, from the examples according to the invention with the respective epoxides (epoxy resin, epoxy homopolymer) outside the measuring range, the epoxy resin and the epoxy homopolymer became a thermoset.

Claims

Claims

1. A thermally curable adhesive film comprising at least one layer of an adhesive which

 at least one (co) polymer (A) functionalized with epoxy groups with a weight-average molar mass in the range from 5,000 g / mol to 5,000,000 g / mol and / or at least one epoxy-containing compound (B) which is obtained from (Co ) Polymer (A) is different;

 at least one radical generator (C);

 at least one photo acid generator (D);

 optionally at least one matrix polymer as film former (E); and

 optionally comprises or consists of at least one additive (F).

2. Adhesive film according to the preceding claim, characterized in that at least one (co) polymer (A) functionalized with aliphatic epoxy groups is present with a weight-average molar mass in the range from 5,000 g / mol to 500,000 g / mol,

 and or

 the weight-average molar mass of the (co) polymer (A) is at least 10,000 g / mol, preferably at least 20,000 g / mol;

 and or

 the weight-average molar mass of the (co) polymer (A) is at most 2,000,000 g / mol, preferably at most 1,000,000 g / mol, more preferably at most 100,000 g / mol;

 and or

 cycloaliphatic epoxides are used for the functionalization of the (co) polymer (A), in particular 3,4-epoxycyclohexyl-substituted monomers, in particular selected from the group: 3,4-epoxycyclohexylmethyl methacrylate, 3,4-

Epoxycyclohexyl methyl acrylate, 3,4-epoxycyclohexyl methacrylate and 3,4-epoxycyclohexyl acrylate or mixtures thereof;

 and or

the at least one (co) polymer (A) based on more than 5 to 100% by weight, preferably 10 to 100% by weight, further preferably 25 to 100% by weight, further preferably 50 to 100% by weight based on the total of the monomers on which the (co) polymer (A) is based, has at least one type of (meth) acrylic (co) monomer (a) functionalized with a cycloaliphatic epoxide.

3. Adhesive film according to one of the preceding claims, characterized in that it contains at least one (co) polymer (B1) containing glycidyl ether groups, wherein that at least one (co) polymer (B1) with a weight-average molar mass in the range of 5,000 g / mol to 500,000 g / mol is contained;

 and or

 the weight-average molar mass of the (co) polymer (B1) is at least 10,000 g / mol, preferably at least 20,000 g / mol;

 and or

 the weight-average molar mass of the (co) polymer (B1) is at most 2,000,000 g / mol, preferably at most 1,000,000 g / mol, more preferably at most 100,000 g / mol.

4. Adhesive film according to one of the preceding claims, characterized in that the at least one radical generator (C) comprises at least two organyl groups and / or

 the at least one radical generator (C) is a peroxide and / or

 Dicumyl peroxide is used as peroxide (C1).

5. Adhesive film according to one of the preceding claims, characterized in that the amount of radical generator (C) in the adhesive is in the range from 0.1 to 10% by weight, preferably from 1 to 8% by weight, very preferably from 2, 5 to 7 wt .-% is selected.

6. Adhesive film according to one of the preceding claims, characterized in that at least one matrix polymer (E) is a thermoplastic polymer, preferably a thermoplastic, semicrystalline polymer, in particular all thermoplastic polymers are semicrystalline;

 and or

 that the at least one matrix polymer (E) is a polyurethane, in particular all

Matrix polymer polyurethanes;

 and or

 that the matrix polymers (E) have maximum softening temperatures and / or decrystallization temperatures, measured by means of DSC, of at most 25 ° C., preferably at most 0 ° C;

 and or

that the matrix polymers (E) have a maximum glass transition temperature, measured by means of DSC, of not more than -25 ° C., preferably not more than -35 ° C.

7. Adhesive film according to one of the preceding claims, characterized in that the at least one (co) polymer (A) and / or the at least one epoxy-containing compound (B) in 5 to 99.8 wt .-%, preferably 10 to 90% by weight, more preferably 20 to 80% by weight, in the adhesive is / are;

 and or

 the at least one radical generator (C) is contained in 0.1 to 10.0% by weight, preferably 1.0 to 8.0% by weight, more preferably 2.5 to 7.0% by weight;

 and or

 the at least one photo acid generator (D) in 0.1 to 10.0% by weight, preferably 1.0 to 5.5% by weight, more preferably 1.5 to 4.0% by weight, even more preferably 2.0 to 3.0% by weight is included;

 and or

 the at least one matrix polymer (E) in 2.0 to 94.5% by weight, preferably 25.0 to 92.5% by weight, more preferably 50.0 to 91.5% by weight, even more preferably 75.0 to 90.5% by weight, most preferably 80.0 to 90.0% by weight

 and or

 at least one additive (F) in 0.1 to 50% by weight, preferably 0.15 to 25% by weight, more preferably 0.2 to 10% by weight, even more preferably 0.25 to 5% by weight. -% is included, wherein the wt .-% each refer to the total weight of the adhesive.

8. Adhesive film according to one of the preceding claims, characterized in that essentially no thermal acid generator (TAG (Thermal Acid Generator)) is contained in the adhesive, preferably in less than 0.1% by weight, more preferably 0.01% by weight %, most preferably less than 0.001% or none at all.

9. Adhesive film according to one of the preceding claims, characterized in that the adhesive layer has a layer thickness of less than 500 pm, preferably from 2 to 250 pm, more preferably from 10 to 200 pm.

10. Adhesive film according to one of the preceding claims, characterized in that the thermal curing, determined by the enthalpy measured by means of DSC, takes place only at 120 to 250 ° C, preferably at 130 to 220 ° C, more preferably at 140 to 200 ° C .

1 1. Composite comprising two substrates by an adhesive film according to one of the

Claims 1 to 10 or an adhesive according to one of claims 1 to 11 are glued.

12. A method for joining two substrates using an adhesive film according to one of claims 1 to 10 or an adhesive according to one of claims 1 to 10.

13. The method according to claim 12, wherein the substrates largely absorb light in the UV range, preferably the absorption in the UV range at 50%, more preferably at 75%, more preferably at 90%, more preferably at 95% or and / or UV-impermeable.