ADHESIVES WITH ACTIVABLE GETTER MATERIALS

Description

[0001] The present invention relates to an adhesive comprising a getter material and optionally a solvent, an adhesive tape comprising this adhesive, the use of such an adhesive and such an adhesive tape, and a method for applying the adhesive or the adhesive tape. Furthermore, the invention relates to an adhesive tape comprising this adhesive and the use of such an adhesive.

[0002] Such adhesives are well known.

[0003] US 2010 / 159238 describes a multilayer adhesive composition comprising a first layer made from a first composition comprising a part A and a part B, wherein part A comprises a plasticizer, a crosslinking agent and an adhesion promoter, wherein part B comprises a moisture protectant and an abrasion protectant, and wherein the first layer is substantially sulfide-free.

[0004] DE10 2012 211 335 relates to a method for protecting an electronic arrangement arranged on a substrate and comprising organic components, wherein a cover is applied to the electronic arrangement in such a way that the electronic arrangement is at least partially covered by the cover, wherein the cover is adhesively bonded at least partially to the substrate and / or to the electronic arrangement, wherein the bonding is effected by means of at least one layer of an adhesive in an adhesive tape, wherein the adhesive comprises a getter material capable of sorbing at least one permeable substance, wherein the getter material is present in the adhesive in a proportion of not more than 2% by weight, based on the adhesive with the getter material.

[0005] US 5304419 discloses a hermetically sealed housing containing an electronic device, the inner surface of which is at least partially coated with a pressure-sensitive adhesive containing 4 to 40 vol% of a finely divided solid desiccant having an average particle size of 0.2 to 100 µm, the coating having a thickness of 1 to 25 mm and being effective to keep an environment within the housing substantially free of moisture and substantially free of free solid particles.

[0006] US 6121354 claims a hot-melt one-component sealant consisting of a styrene block copolymer, a moisture-curable silylated polyurethane prepolymer, an aromatic adhesive resin, a polar adhesive resin, a polyethylene wax and an organofunctional silane.

[0007] WO 2004 / 009720 relates to a convertible pressure-sensitive adhesive composition consisting of 15 to 80 wt% of a polymer having a softening point of more than 60°C, 20 to 85 wt% of a polymerizable resin having a softening point of less than 30°C and a latent initiator in an amount sufficient to induce the reaction between the polymer and the resin and optionally a crosslinking agent.

[0008] WO 201515947 describes a translucent, multiphase adhesive comprising at least one continuous phase and dispersely distributed domains, wherein the at least one continuous phase has a refractive index of more than 1.45 and a permeation rate for water vapor of less than 100 g / m 2< and the disperse domains are present in a weight fraction of not more than 10 wt.% in the adhesive, wherein the disperse domains are polymeric in nature, have a WVTR of less than 100 g / m 2< and a refractive index of less than 1.45.

[0009] WO 2005 / 118679 discloses an adhesive or sealant composition comprising a crosslinkable polymer, a crosslinking catalyst for the polymer, a rheology modifier and a water scavenger, wherein the crosslinkable polymer has silyl end groups and has an equivalent molecular weight between 10,000 and 20,000.

[0010] The getter material contained in the adhesive is capable of capturing permeable substances such as water, oxygen, low-molecular-weight hydrocarbons, or volatile organic compounds that penetrate the adhesive. Such adhesives are used, for example, to encapsulate objects that need to be protected from water. In this case, the permeable substance is water. A particularly important application for such getters is (opto)electronic devices. (Opto)electronic devices are increasingly being used in commercial products. Such devices comprise inorganic or organic electronic structures, for example, organic, organometallic, or polymeric semiconductors, or combinations thereof. These devices and products are designed to be rigid or flexible depending on the desired application, with a growing demand for flexible devices.Such devices are manufactured using printing processes such as letterpress, gravure, screen printing, planographic printing, or so-called "non-impact printing" such as thermal transfer printing, inkjet printing, or digital printing. Vacuum processes such as chemical vapor deposition (CVD), physical vapor deposition (PVD), plasma-enhanced chemical or physical deposition (PECVD), sputtering, (plasma) etching, or vapor deposition are also frequently used, with structuring usually performed using masks.

[0011] Examples of (opto-)electronic applications that are already commercial or of interest in terms of their market potential include electrophoretic or electrochromic structures or displays, organic or polymer light-emitting diodes (OLEDs or PLEDs) in indicator and display devices or as lighting, electroluminescent lamps, light-emitting electrochemical cells (LEECs), organic solar cells, preferably dye or polymer solar cells, inorganic solar cells, preferably thin-film solar cells, in particular based on silicon, germanium, copper, indium and selenium, perovskite solar cells, organic field-effect transistors, organic switching elements, organic optical amplifiers, organic laser diodes, organic or inorganic sensors or even organic or inorganic-based RFID transponders.

[0012] Further applications of encapsulating adhesive tapes are known in the field of battery technology, in particular in the field of flexible microbatteries and thin-film batteries, especially those comprising lithium-containing cathodes, anodes or electrolytes.

[0013] Accordingly, in this document, an organic (opto-)electronic arrangement is understood to mean an electronic arrangement which comprises at least one electronically functional, at least partially organic component - for example, organometallic compounds - or whose electronically functional structure has a thickness of less than 20 µm.

[0014] A technical challenge for achieving sufficient lifetime and functionality of (opto-)electronic devices in the field of inorganic and / or organic (opto)electronics, but especially in the field of organic (opto)electronics, is protecting the components contained therein from permeates. Permeates can be a variety of low-molecular-weight organic or inorganic compounds, particularly water vapor and oxygen.

[0015] A large number of (opto-)electronic devices in the field of inorganic and / or organic (opto)electronics, particularly those using organic raw materials, are sensitive to both water vapor and oxygen, with the ingress of water or water vapor being considered a major problem for many devices. Therefore, protection through encapsulation is required throughout the lifetime of the electronic device, as otherwise performance deteriorates over the period of use. For example, oxidation of the components can drastically reduce the luminosity of light-emitting devices such as electroluminescent lamps (EL lamps) or organic light-emitting diodes (OLEDs), the contrast of electrophoretic displays (EP displays), and the efficiency of solar cells within a very short period of time.

[0016] To achieve the best possible seal, special barrier adhesives (also known as water vapor barrier adhesives) are used. A good adhesive for sealing (opto-)electronic components has low permeability to oxygen and especially to water vapor, has sufficient adhesion to the assembly, and can flow easily onto it.

[0017] To characterize the barrier effect, the oxygen transmission rate (OTR) and the water vapor transmission rate (WVTR) are usually specified. The respective rate indicates the area- and time-related flow of oxygen or water vapor through a film under specific conditions of temperature and partial pressure, as well as other measurement conditions such as relative humidity. The lower these values ​​are, the better suited the respective material is for encapsulation. The permeation specification is not based solely on the WVTR or OTR values, but always also includes information on the mean permeation path length, such as the thickness of the material or a normalization to a specific path length.

[0018] Permeability P is a measure of a body's permeability to gases and / or liquids. A low P value indicates a good barrier effect. Permeability P is a specific value for a defined material and a defined permeate under steady-state conditions at a specific permeation path length, partial pressure, and temperature. Permeability P is the product of the diffusion term D and the solubility term S: P = D * S

[0019] The solubility term S primarily describes the affinity of the barrier adhesive for the permeate. In the case of water vapor, for example, a low value for S is achieved by hydrophobic materials. The diffusion term D is a measure of the mobility of the permeate in the barrier material and is directly dependent on properties such as molecular mobility or free volume. Relatively low values ​​for D are often achieved in highly cross-linked or highly crystalline materials. However, highly crystalline materials are generally less transparent, and greater cross-linking leads to lower flexibility. The permeability P usually increases with an increase in molecular mobility, for example, when the temperature is increased or the glass transition point is exceeded.

[0020] Approaches to increasing the barrier effect of an adhesive must consider the two parameters D and S, particularly with regard to their influence on water vapor and oxygen permeability. In addition to these chemical properties, the effects of physical influences on permeability must also be considered, particularly the mean permeation path length and interfacial properties (flow behavior of the adhesive, adhesion). The ideal barrier adhesive exhibits low D and S values ​​with very good adhesion to the substrate.

[0021] A low solubility term S alone is usually insufficient to achieve good barrier properties. A classic example of this is siloxane elastomers. These materials are extremely hydrophobic (low solubility term), but due to their freely rotatable Si-O bond (large diffusion term), they exhibit comparatively low barrier effectiveness against water vapor and oxygen. Therefore, a good balance between the solubility term S and the diffusion term D is necessary for good barrier properties.

[0022] Also described are barrier adhesives based on styrene block copolymers and, if possible, hydrogenated resins (see DE 10 2008 047 964 A1). Permeation values ​​(WVTR) of widely used adhesive systems are also specified here (measured at 37.5°C and 90% relative humidity). Typical acrylate-based PSAs range between 100 g / m 2 < d and 1000 g / m 2 < d. Silicone PSAs have even higher water permeation values ​​of over 1000 g / m 2 < d due to the high mobility of the chains. If styrene block copolymers are used as the elastomer component, WVTR values ​​in the range of 50 - 100 g / m 2 < d are achieved for non- or incompletely hydrogenated systems, and values ​​below 50 g / m 2 < d for hydrogenated systems (e.g., SEBS). Particularly low WVTR values ​​of below 15 g / m 2 < d are achieved with both pure poly(isobutylene) elastomers and block copolymers of styrene and isobutylene.

[0023] One way to further improve the barrier effect is the use of substances that react with the penetrating substances, so-called permeable substances, such as water or oxygen. Permeable substances, such as oxygen or water vapor, that penetrate the (opto-)electronic device are then chemically or physically bound to these substances, preferably chemically, thus increasing the breakthrough time ("lag time"). These substances are referred to in the literature as "getters," "scavengers," "desiccants," or "absorbers." The term "getter" is used below. A getter or getter material is a material capable of sorbing at least one permeable substance.

[0024] Getter materials include, for example, salts such as cobalt chloride, calcium chloride, calcium bromide, lithium chloride, lithium bromide, magnesium chloride, barium perchlorate, magnesium perchlorate, zinc chloride, zinc bromide, silicic acids (e.g. silica gel), aluminum sulfate, calcium sulfate, copper sulfate, barium sulfate, magnesium sulfate, lithium sulfate, sodium sulfate, cobalt sulfate, titanium sulfate, sodium dithionite, sodium carbonate, potassium disulfite, potassium carbonate, magnesium carbonate, titanium dioxide, diatomaceous earth, zeolites, layered silicates such as montmorillonite and bentonite, metal oxides such as barium oxide, calcium oxide, iron oxide, magnesium oxide, sodium oxide, potassium oxide, strontium oxide, aluminum oxide (activated alumina); furthermore, carbon nanotubes, activated carbon, phosphorus pentoxide and silanes; easily oxidizable metals such as iron, calcium, sodium and magnesium; metal hydrides such as calcium hydride, barium hydride, strontium hydride, sodium hydride and lithium aluminum hydride;Hydroxides such as potassium hydroxide and sodium hydroxide, metal complexes such as aluminum acetylacetonate; furthermore, organic absorbers, for example, polyolefin copolymers, polyamide copolymers, PET copolyesters, anhydrides of simple and polycarboxylic acids such as acetic anhydride, propionic anhydride, butyric anhydride or methyltetrahydrophthalic anhydride, isocyanates or other hybrid polymer-based absorbers, which are usually used in combination with catalysts such as cobalt; other organic absorbers such as weakly cross-linked polyacrylic acid, polyvinyl alcohol, ascorbates, glucose, gallic acid or unsaturated fats and oils.

[0025] In keeping with their function, getter materials are preferably used as materials that are essentially free of permeates, for example, anhydrous. This distinguishes getter materials from similar materials that are used as fillers. For example, silica in the form of fumed silica is often used as a filler. However, if this filler is stored under ambient conditions as usual, it absorbs water from the environment and is no longer functional as a getter material to a technically usable extent. Only silica that has been dried or kept dry can be used as a getter material. However, it is also possible to use materials that are already partially complexed with permeates, for example CaSO 4 *1 / 2H 2 O (calcium sulfate hemihydrate) or partially hydrated silicas, which by definition exist as compounds of the general formula (SiO 2 )m*nH 2 O.

[0026] As described above, silicas are understood to be compounds of the general formula (SiO 2 )m*nH 2 O. These are silicon dioxide produced by wet-chemical, thermal, or pyrogenic processes. Among the silicas, particularly suitable getter materials are silica gels, for example, silica gels impregnated with cobalt compounds as a moisture indicator (blue gel), and pyrogenic silicas.

[0027] "Sorption" refers to the process of absorption of one or more substances by another substance—in this case, by the getter material. The getter could therefore also be referred to as a "sorbent" or "sorbent agent." The sorption of the permeable substance(s) by the getter material can occur, for example, through absorption or adsorption, with adsorption occurring in the form of both chemisorption and physisorption.

[0028] A "permeable substance" is defined as a substance that, as a gaseous or liquid, or possibly also as a solid, can penetrate the adhesive to be protected and subsequently permeate it. Such substances were referred to above and are referred to below as "permeates." The permeates can originate from the adhesive itself or from the environment, for example, from the carrier material of an adhesive tape coated with the adhesive. Low-molecular-weight organic compounds such as solvent residues, residual monomers, oils, resin components, plasticizers, and water often originate from the adhesive or the adhesive tape itself. Water, volatile organic compounds (VOCs), low-molecular-weight hydrocarbons, and oxygen often originate from the environment.

[0029] For example, the binding of the penetrating water occurs either physically through adsorption, typically on silica, molecular sieves, zeolites, or sodium sulfate. Chemically, water is bound via alkoxysilanes, oxazolidines, isocyanates, barium oxide, phosphorus pentoxide, alkali and alkaline earth oxides (such as calcium oxide), metallic calcium, or metal hydrides (WO 2004 / 009720 A2).

[0030] Described as such getters in adhesives are mainly inorganic fillers such as calcium chloride or various oxides (compare US 5,304,419 A, EP 2 380 930 A1 or US 6,936,131 A).

[0031] Organic getters are also described in adhesives, for example, in EP 2 597 697 A1, in which polymeric alkoxysilanes are used as getters. Numerous different silanes as getters in adhesives are mentioned in WO 2014 / 001005 A1. From the wide selection of alkoxysilanes, the person skilled in the art would initially select easily hydrolyzable ones, such as methoxysilanes. However, particularly good activities are achieved in the encapsulation of organic electronic structures when the alkoxy group is an ethoxy group. Surprisingly, it has been shown that ethoxysilanes, which are less reactive than methoxysilanes, reduce moisture permeation significantly better, especially at high temperatures. This is unexpected, since methoxysilanes normally have a higher reactivity than the corresponding ethoxysilanes (see Wacker Product Description 6085e / 09.13 "GE-NIOSL ®< ", page 11 from September 2013 (09.13)).

[0032] Difficulties with such adhesives or tapes made from such adhesives lie in their storage and transport until their final use. An adhesive or tape containing a getter must be stored and / or transported hermetically sealed until use. Penetrating permeates, particularly moisture, are absorbed by the getter, consuming it and thus reducing its barrier properties. This is particularly disadvantageous for electronics applications, as the adhesive tapes are usually cut into die-cuts by external converters and thus come into contact with moisture. Thus, the water absorbers in the tape are consumed to varying degrees depending on the time the converter requires for die-cutting and the existing humidity.Apart from the reduction of the getter function, i.e. the ability to act as a getter - and in this case to absorb water - it is therefore no longer possible to make a clear statement about the getter capacity, i.e. the ability to absorb water, of the adhesive or adhesive tape after application.

[0033] The invention was therefore based on the object of providing an adhesive which tolerates short-term contact with permeates, such as moisture in particular, until application by the user, without the getter capacity being significantly impaired.

[0034] Surprisingly, it has been found that this object is achieved by an adhesive composition as defined in claim 1. Preferred embodiments of the present invention are set forth in the dependent claims.

[0035] The present invention is accordingly based on the finding that such an adhesive can be obtained if an adhesive of the type mentioned above contains a catalyst for the reaction of the getter material from the group of ethoxysilanes with a permeate, which catalyst can be activated by an external stimulus. The present invention is particularly suitable for water as the permeate.

[0036] With such an adhesive, the getter function can be activated when needed, particularly when the adhesive is applied and intended to seal an object against the permeate, for example, water vapor. Such an adhesive can be described as "switchable." Its permeate-binding function, especially its water-binding function, can be "switched on" by an external stimulus or trigger, in which the catalyst is activated by the external stimulus or trigger. During storage or transport of the adhesive, the catalyst, and thus the getter function, is not yet activated or switched on. The getter does not react, or only reacts appreciably, with the permeate, especially with water vapor, and is not consumed.Only when the adhesive is applied and is actually intended to seal an object against water vapor and protect it from penetration, the getter is activated or "switched on" and begins its function.

[0037] The catalyst changes the rate constant for the reaction of the getter with the permeate, especially water (vapor). A change within the meaning of the present invention occurs when the rate constant is increased by at least a factor of 5, preferably 10, particularly preferably at least a factor of 50.

[0038] The catalyst can, for example, be a latent acid or a latent base. This means that, after activation, the catalyst can change the chemical environment with regard to its acid-base properties and thus accelerate a reaction whose rate depends on this environment. The dependence of the reaction rate on pH is described using the example of a silane in J. Org. Chem., Vol. 51, No. 20, 1986, pages 3827-3830. Other pH-dependent reactions with water include the hydrolysis of anhydrides, carbodiimides, oxazolidones, esters, or isocyanates.

[0039] Examples of such latent systems that can cause a change in the environment are systems based on onium salts, especially sulfonium and iodonium, as well as metallocene-based systems.

[0040] In the case of water, the getter material has its lowest activity towards water preferably in a neutral or quasi-neutral environment. A "neutral environment" is defined as an environment that would correspond to a pH of 7 in aqueous solution. A "quasi-neutral environment" is defined as the range that would correspond to a pH between 6 and 8 in aqueous solution, preferably a pH of 6.5 to 7.5. In this case, the getter material has its lowest reaction rate with water in a neutral environment. The reaction rate is so low that no significant reaction with water (vapor) occurs. However, if the environment becomes acidic or basic, the reaction rate increases significantly.

[0041] Other catalysts known to those skilled in the art are also suitable for the invention. This applies in particular to nano- or microencapsulated catalysts. These catalysts are activated by breaking the encapsulation.

[0042] The amount of catalyst present in the adhesive composition of the invention is preferably less than 5% by weight, more preferably less than 2% by weight, and in particular less than 1% by weight. Thus, relatively small amounts are sufficient to achieve the effect of the invention.

[0043] "External stimulus" means an external influence on the catalyst that activates it.

[0044] Particularly suitable external stimuli are UV radiation, temperature changes, microwave radiation, or visible light, with UV radiation being particularly preferred. UV radiation allows for easy activation; on the other hand, it is unlikely that the adhesive will be accidentally exposed to UV radiation before the desired application, thus preventing unintentional activation.

[0045] The adhesive composition particularly preferably comprises an adhesive base composed of at least one elastomer and at least one adhesive resin. A particularly suitable adhesive composition thus comprises the adhesive base, getter material, optionally a solvent, and a catalyst for the reaction of the getter material with a permeate, which catalyst can be activated by an external stimulus.

[0046] Furthermore, the adhesive composition according to the invention is preferably pressure-sensitive. This enables particularly good handling, since the adhesive composition adheres to the area to be bonded even before crosslinking.

[0047] The adhesive composition of the invention is particularly suitable if it also contains at least one reactive resin with at least one curable group. Such adhesive compositions can be applied, but are initially still deformable. Only after the curable group has reacted does the adhesive composition cure and develop its full adhesive effect.

[0048] Cyclic ether, vinyl, acrylate, methacrylate, hydroxyl, amino, and / or isocyanate are particularly suitable as curable groups. Several different curable groups can also be present in the reactive resin.

[0049] When the adhesive contains a reactive resin, systems in which the stimulus for the catalyst for the reaction of the getter material with water is simultaneously the initiator for the curing of the reactive resin are particularly easy to handle. UV radiation is particularly suitable as a stimulus in this case. The catalyst is then a photocatalyst.

[0050] On the other hand, adhesives that do not contain reactive resin are also well suited. Such adhesives do not require the additional curing step, so in such a system, any requirements regarding the curing of the reactive groups need not be taken into account. The only thing that needs to be ensured is that the getter material is activated as required.

[0051] Pressure-sensitive adhesives in particular are particularly suitable as adhesives without reactive resin.

[0052] Preferably, the adhesive is a barrier adhesive whose adhesive base - in the case of the presence of a reactive resin after its curing - has a water vapor permeation rate of less than 100 g / m 2< d, preferably less than 50 g / m 2< d, in particular less than 15 g / m 2< d.

[0053] The adhesive preferably has a neutral or quasi-neutral environment prior to catalyst stimulation. Thus, the adhesive preferably contains no acidic or basic groups, in particular no organic acids, acrylic acids, methacrylic acids, amines, amides, or their polymers.

[0054] The getter material is particularly preferably at least one compound selected from the group comprising alkoxysilanes and alkoxysiloxanes. These compounds ensure a neutral environment. The alkoxysilanes and alkoxysiloxanes can preferably be present as monomers or as oligomers with 2 to 40 repeating SiR2 groups. The compounds can be chain-like or ring-like.

[0055] "Silanes" are understood to mean compounds of the general formula R a -Si-X 4-a or their partial condensation products. In the formula, a represents an integer from 0 to 3, preferably 0 or 1. X represents a hydrolyzable group, for example and preferably a halogen atom, in particular chlorine, an alkoxy group such as a methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, or tert-butoxy group, or an acetoxy group. Further examples of hydrolyzable groups known to the person skilled in the art can also be used for the purposes of the present invention. If several substituents X are present, they may be identical or different from one another.R represents an optionally substituted hydrocarbon radical, for example a methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, tert-butyl group, a pentyl group and its branched isomers, a hexyl group and its branched isomers, a heptyl group and its branched isomers, an octyl group and its branched isomers, a nonyl group and its branched isomers, a decyl group and its branched isomers, an undecyl group and its branched isomers, a dodecyl group and its branched isomers, a tetradecyl group and its branched isomers, a hexadecyl group and its branched isomers, an octadecyl group and its branched isomers or an eicosyl group and its branched isomers. The hydrocarbon residues may also contain ring-shaped and / or aromatic moieties. Representative structures include cyclohexyl, phenyl, and benzyl groups.Optionally, the hydrocarbon radical(s) R contain(s), for example, one or more heteroatom-containing substituents such as amino groups, aminoalkyl groups, glycidyloxy groups, (meth)acryloxy groups, and the like. If multiple R substituents are present, they may be identical or different from one another.

[0056] Ein als Gettermaterial einsetzbares Silan ist bevorzugt ausgewählt aus der Gruppe umfassend N-(2-Aminoethyl)-3-aminopropyltrimethoxysilan, N-(2-Aminoethyl)-3-aminopropy-Itriethoxysilan, 3-Aminopropyltrimethoxysilan, 3-Aminopropyltriethoxysilan, 3-Aminopropy-Idiethoxymethylsilan, N-(2-Aminoethyl)-3-aminopropyldimethoxymethylsilan, (N-Butyl)-3-aminopropyltrimethoxysilan, 3-(N-Ethylamino)-2-methylpropyltrimethoxysilan, 4-Amino-3,3-dimethylbutyltrimethoxysilan, 4-Amino-3,3-dimethylbutyldimethoxymethylsilan, (N-Cyclohexyl)-aminomethyldimethoxymethylsilan, (N-Cyclohexyl)-aminomethyltrimethoxysilan, (N-Phenyl)-3-aminopropyltrimethoxysilan, (N-Phenyl)-aminomethyldimethoxymethylsilan, (N-Benzyl-2-aminoethyl)-3-aminopropyltrimethoxysilan, [2-(N-Benzyl-N-vinylamino)-ethyl]-3-aminopropyltrimethoxysilan Hydrogenchlorid, [2-(N-Benzyl-N-vinylamino)-ethyl]-3-aminopropyltrimethoxysilan, Bis-(3-propyltriethoxysilyl)-amin, Vinyltrimethoxysilan, Vinyltriethoxysilan, Vinyl-tri(2-methoxyethoxy)-silan,Vinyltriisopropoxysilan, Vinyldimethoxymethylsilan, Vinyltriacetoxysilan, 3-Triethoxysilylpropylbernsteinsäureanhydrid, 3-Glycidyloxypropyltrimethoxysilan, 3-Glycidyloxypropyltriethoxysilan, 2-(3,4-Epoxycyclohexyl)-ethyltriethoxysilan, 2-(3,4-Epoxycyclohexyl)-ethyltrimethoxysilan, 2-(3,4-Epoxycyclohexyl)-ethylmethyldimethoxysilan, 2-(3,4-Epoxycyclohexyl)-ethylmethyldiethoxysilan, Triethoxyoctylsilan, Trimethoxyoctylsilan, 3-Glycidyloxypropyldiethoxymethylsilan, 3-Methacryloyloxypropyltrimethoxysilan, 3-Methacryloyloxypropyltriethoxysilan, 3-Methacryloyloxypropyltriisopropoxysilan, 3-Methacryloyloxypropyldimethoxymethylsilan, 3-Methacryloyloxypropyldiethoxymethylsilan, 3-Chloropropyltrimethoxysilan, 3-Chloropropyltriethoxysilan, 3-Isocyanatopropyltrimethoxysilan, 3-Isocyanatopropyltriethoxysilan, Isocyanatomethyltrimethoxysilan, Isocyanatomethyldimethoxymethylsilan, Tris-[3-(trimethoxysilyl)-propyl]-isocyanurat, 3-Ureidopropyltrimethoxysilan, 3-Ureidopropyltriethoxysilan,2-Hydroxy-4-(3-triethoxysilylpropoxy)-benzophenone, 4-(3'-chlorodimethylsilylpropoxy)-benzophenone, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyldimethoxymethylsilane, bis-(3-triethoxysilylpropyl)-disulfane, bis-(3-triethoxysilylpropyl)-tetrasulfane, bis-(triethoxysilylpropyl)-polysulfane, and octadecylaminodimethyltrimethoxysilylpropylammonium chloride. Other non-crosslinking alkoxysilanes can also be used as getter materials.

[0057] Siloxanes within the meaning of the invention are understood to be compounds that have at least two SiR 2 groups linked via an oxygen atom. In the alkoxysiloxanes particularly suitable for the invention, at least one R radical is an alkoxy group. Examples of siloxanes particularly suitable for the invention are oligomers or polymers of the silanes mentioned in the preceding paragraph.

[0058] The getter preferably has at least one curable group. Particularly suitable curable groups are cyclic ether, vinyl, acrylate, methacrylate, hydroxyl, amino, or isocyanate.

[0059] In the case of alkoxysiloxanes as getters, the alkoxysiloxane preferably has one alkoxy group and one curable group per silicon atom. The alkoxy group can be the same as or different from neighboring silicon alkoxy groups. Likewise, the curable group of neighboring repeating units can be the same or different.

[0060] The getter material has at least one ethoxysilane group and at least one curable group, wherein the curable group is a cyclic ether group. An epoxy or oxirane group is particularly suitable as the cyclic ether group, with the silanes 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane and especially 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane and 2-(3,4-epoxycyclohexyl)ethylmethyldiethoxysilane being particularly preferred.

[0061] Adhesives exhibit particularly good properties in which the amount of getter material is at least 2 wt.%, preferably at least 3 wt.%, and in particular at least 5 wt. Adhesives in which the amount of getter material is 3 to 15 wt.%, preferably 4 to 10 wt.%, and in particular 4.5 to 7 wt.% are particularly advantageous.

[0062] The proportion of reactive resin in the adhesive is from 15 to 80 wt.%, in particular from 20 to 70 wt.%, and particularly preferably from 25 to 65 wt.%. To achieve good handling and elastic adhesive after curing, a preferred reactive resin proportion is 15 to 35 wt.%, in particular 20 to 30 wt.%. For more highly cross-linked bonds, reactive resin proportions of 65 to 80 wt.% are preferred. Reactive resin proportions of 35 to 65 wt.% are particularly balanced in terms of elasticity and degree of cross-linking.

[0063] In a preferred embodiment, the reactive resin contains epoxy groups, particularly aliphatic and most preferably cycloaliphatic epoxy groups. Reactive resins containing glycidyl and / or epoxycyclohexyl groups as curable groups are particularly suitable.

[0064] Particularly suitable are adhesives in which the reactive resin and alkoxysilane or alkoxysiloxane have similar, in particular identical, curable groups. In this case, the reactive resin and alkoxysilane or alkoxysiloxane can polymerize and crosslink particularly well with each other. "Similar functional curable groups" are understood to mean those that are chemically very similar to one another, such as cyclic ethers with different ring sizes or epoxy ethers whose cycloaliphatic frameworks have different ring sizes.

[0065] In a preferred embodiment, the adhesive is cured cationically, thermally, or by radiation. Furthermore, it is preferred that the adhesive contains at least one type of photoinitiator for the cationic curing of the crosslinkable component.

[0066] In a particularly preferred embodiment, the adhesive contains a reactive resin, and the steps of curing and activating the getter occur simultaneously, and curing and activation are induced in the same way. For example, the crosslinking reaction of the reactive resin can be initiated by UV radiation. UV radiation can also cause a change in the environment from neutral to, for example, acidic, which in turn results in the activation of the getter. Parallel curing and activation is particularly suitable because only one step is required after the adhesive or adhesive tape has been applied. Likewise, only one device, such as a UV radiation source, is required. Curing and getter activation can also be thermally induced.

[0067] Pressure-sensitive adhesives (PSAs) are adhesives that allow for a permanent bond with the substrate even under relatively light pressure and can be removed from the substrate after use, leaving essentially no residue. Pressure-sensitive adhesives (PSAs) are permanently tacky at room temperature, meaning they have a sufficiently low viscosity and high tackiness, allowing them to wet the surface of the substrate even under light pressure. The bondability of such adhesives is based on their adhesive properties, and their removability on their cohesive properties. Various materials can be used as the basis for PSAs.

[0068] The polymer can be a single polymer, but can also be a mixture of two or more different polymers. The at least one polymer can, in particular, be an elastomer or a thermoplastic.

[0069] In principle, all elastomers commonly used in the field of pressure-sensitive adhesives can be used as elastomers, as described, for example, in the "Handbook of Pressure Sensitive Adhesive Technology" by Donatas Satas (Satas & Associates, Warwick 1999).

[0070] Preferably, in the sense of the application, the elastomers used are chemically constructed from at least one olefinic monomer or from polyurethane and are, for example, elastomers based on polyurethanes, natural rubbers, synthetic rubbers such as butyl, (iso)butyl, nitrile or butadiene rubbers, styrene block copolymers with an elastomer block made of unsaturated or partially or fully hydrogenated polydiene blocks (polybutadiene, polyisoprene, poly(iso)butylene, copolymers of these and other elastomer blocks familiar to the person skilled in the art), polyolefins, fluoropolymers and / or silicones.

[0071] Preferably, the at least one elastomer is composed of at least one olefinic monomer and / or at least one polyurethane. Particularly preferably, the elastomer is at least one vinylaromatic block copolymer.

[0072] If rubber or synthetic rubber or blends thereof are used as the base material for the pressure-sensitive adhesive, the natural rubber can in principle be selected from all available qualities such as crepe, RSS, ADS, TSR or CV types, depending on the required purity and viscosity level, and the synthetic rubber or synthetic rubbers can be selected from the group of randomly copolymerized styrene-butadiene rubbers (SBR), butadiene rubbers (BR), synthetic polyisoprenes (IR), butyl rubbers (IIR), halogenated butyl rubbers (XIIR), acrylate rubbers (ACM), ethylene-vinyl acetate copolymers (EVA) or polyurethanes and / or blends thereof.

[0073] Any type of thermoplastic known to the person skilled in the art can also be used as the at least one polymer, as mentioned, for example, in the textbooks "Chemistry and Physics of Synthetic Polymers" by JMG Cowie (Vieweg, Braunschweig) and "Macromolecular Chemistry" by B. Tieke (VCH Weinheim, 1997). These include, for example, poly(ethylene), poly(propylene), poly(vinyl chloride), poly(styrene), poly(oxymethylenes), poly(ethylene oxide), poly(ethylene terephthalate), poly(carbonates), poly(phenylene oxides), poly(urethanes), poly(ureas), phenoxy resins, acrylonitrile butadiene styrene (ABS), poly(amides) (PA), poly(lactate) (PLA), poly(etheretherketone) (PEEK), poly(sulfone) (PSU), and poly(ethersulfone) (PES). Poly(acrylate), poly(methacrylate) and poly(methylmethacrylate) (PMMA) are also possible as polymers, but are not preferred in the sense of the present invention.

[0074] Sulfonium-, iodonium-, and metallocene-based systems are particularly suitable as latent catalysts for the catalysis of alkoxysilane hydrolysis. Examples of sulfonium-based cations can be found in US Pat. No. 6,908,722 B1 (particularly columns 10 to 21).

[0075] Examples of anions that serve as counterions for the above-mentioned cations include tetrafluoroborate, tetraphenylborate, hexafluorophosphate, perchlorate, tetrachloroferrate, hexafluoroarsenate, hexafluoroantimonate, pentafluorohydroxyantimonate, hexachloroantimonate, tetrakispentafluorophenylborate, tetrakis(pentafluoromethylphenyl)borate, bi(trifluoromethylsulfonyl)amide, and tris(trifluoromethylsulfonyl)methide. Furthermore, chloride, bromide, or iodide are also conceivable as anions, particularly for iodonium-based initiators, although initiators that are essentially free of chlorine and bromine are preferred.

[0076] More specifically, the systems that can be used include Sulfonium-Salze (siehe zum Beispiel US 4,231,951 A, US 4,256,828 A, US 4,058,401 A, US 4,138,255 A und US 2010 / 063221 A1) wie Triphenylsulfoniumhexafluoroarsenat, Triphenylsulfoniumhexafluoroborat, Triphenylsulfoniumtetrafluoroborat, Triphenylsulfoniumtetrakis-(pentafluorobenzyl)-borat, Methyldiphenylsulfoniumtetrafluoroborat, Methyldiphenylsulfoniumtetrakis-(pentafluorobenzyl)-borat, Dimethylphenylsulfoniumhexafluorophosphat, Triphenylsulfoniumhexafluorophosphat, Triphenylsulfoniumhexafluoroantimonat, Diphenylnaphthylsulfoniumhexafluoroarsenat, Tritolylsulfoniumhexafluorophosphat, Anisyldiphenylsulfoniumhexafluoroantimonat, 4-Butoxyphenyldiphenylsulfoniumtetrafluoroborat, 4-Chlorophenyldiphenylsulfoniumhexafluoroantimonat, Tris-(4-phenoxyphenyl)-sulfoniumhexafluorophosphat, Di-(4-ethoxyphenyl)-methylsulfoniumhexafluoroarsenat, 4-Acetylphenyldiphenylsulfoniumtetrafluoroborat, 4-Acetylphenyldiphenylsulfoniumtetrakis-(pentafluorobenzyl)-borat,Tris-(4-thiomethoxyphenyl)-sulfoniumhexafluorophosphat, Di-(methoxysulfonylphenyl)-methylsulfoniumhexafluoroantimonat, Di-(methoxynaphthyl)-methylsulfoniumtetrafluoroborat, Di-(methoxynaphthyl)-methylsulfoniumetrakis-(pentafluorobenzyl)-borat, Di-(carbomethoxyphenyl)-methylsulfoniumhexafluorophosphat, (4-Octyloxyphenyl)-diphenylsulfoniumtetrakis-(3,5-bis-trifluoromethylphenyl)-borat, Tris-[4-(4-acetylphenyl)-thiophenyl]-sulfoniumtetrakis-(pentafluorophenyl)-borat, Tris-(dodecylphenyl)-sulfoniumtetrakis-(3,5-bis-trifluoromethylphenyl)-borat, 4-Acetamidphenyldiphenylsulfoniumtetrafluoroborat, 4-Acetamidphenyldiphenylsulfoniumtetrakis-(pentafluorobenzyl)-borat, Dimethylnaphthylsulfoniumhexafluorophosphat, Trifluoromethyldiphenylsulfoniumtetrafluoroborat, Trifluoromethyldiphenylsulfoniumtetrakis-(pentafluorobenzyl)-borat, Phenylmethylbenzylsulfoniumhexafluorophosphat, 5-Methylthianthreniumhexafluorophosphat, 10-Phenyl-9,9-dimethylthioxantheniumhexafluorophosphat,10-Phenyl-9-oxothioxantheniumtetrafluoroborat, 10-Phenyl-9-oxothioxantheniumtetrakis-(pentafluorobenzyl)-borat, 5-Methyl-10-oxothianthreniumtetrafluoroborat, 5-Methyl-10-oxothianthreniumtetrakis-(pentafluorobenzyl)-borat und 5-Methyl-10,10-dioxothianthreniumhexafluorophosphat, lodonium-Salze (siehe zum Beispiel US 3,729,313 A, US 3,741,769 A, US 4,250,053 A, US 4,394,403 A und US 2010 / 063221 A1) wie Diphenyliodoniumtetrafluoroborat, Di-(4-methylphenyl)-iodoniumtetrafluoroborat, Phenyl-4-methylphenyliodoniumtetrafluoroborat, Di-(4-chlorphenyl)-iodoniumhexafluorophosphat, Dinaphthyliodoniumtetrafluoroborat, Di-(4-trifluormethylphenyl)-iodoniumtetrafluoroborat, Diphenyliodoniumhexafluorophosphat, Di-(4-methylphenyl)-iodoniumhexafluorophosphat, Diphenyliodoniumhexafluoroarsenat, Di-(4-phenoxyphenyl)-iodoniumtetrafluoroborat, Phenyl-2-thienyliodoniumhexafluorophosphat, 3,5-Dimethylpyrazolyl-4-phenyliodoniumhexafluorophosphat, Diphenyliodoniumhexafluoroantimonat, 2,2'-Diphenyliodoniumtetrafluoroborat, Di-(2,4-dichlorphenyl)-iodoniumhexafluorophosphat, Di-(4-bromphenyl)-iodoniumhexafluorophosphat, Di-(4-methoxyphenyl)-iodoniumhexafluorophosphat, Di-(3-carboxyphenyl)-iodoniumhexafluorophosphat, Di-(3-methoxycarbonylphenyl)-iodoniumhexafluorophosphat, Di-(3-methoxysulfonylphenyl)-iodoniumhexafluorophosphat, Di-(4-acetamidophenyl)-iodoniumhexafluorophosphat, Di-(2-benzothienyl)-iodoniumhexafluorophosphat, Diaryliodoniumtristrifluormethylsulfonylmethid wie Diphenyliodoniumhexafluoroantimonat, Diaryliodoniumtetrakis-(pentafluorophenyl)-borat wie Diphenyliodoniumtetrakis-(pentafluorophenyl)-borat,, (4-n-Desiloxyphenyl)-phenyliodoniumhexafluoroantimonat, [4-(2-Hydroxy-n-tetradesiloxy)-phenyl]-phenyliodoniumhexafluoroantimonat, [4-(2-Hydroxy-n-tetradesiloxy)-phenyl]-phenyliodoniumtrifluorosulfonat, [4-(2-Hydroxy-n-tetradesiloxy)-phenyl]-phenyliodoniumhexafluorophosphat,[4-(2-Hydroxy-n-tetradesiloxy)-phenyl]-phenyliodoniumtetrakis-(pentafluorophenyl)-borat, Bis-(4-tert-butylphenyl)-iodoniumhexafluoroantimonat, Bis-(4-tert-butylphenyl)-iodoniumhexafluorophosphat, Bis-(4-tert-butylphenyl)-iodoniumtrifluorosulfonat, Bis-(4-tert-butylphenyl)-iodoniumtetrafluoroborat, Bis-(dodecylphenyl)-iodoniumhexafluoroantimonat, Bis-(dodecylphenyl)-iodoniumtetrafluoroborat, Bis-(dodecylphenyl)-iodoniumhexafluorophosphat, Bis-(dodecylphenyl)-iodoniumtrifluoromethylsulfonat, Di-(dodecylphenyl)-iodoniumhexafluoroantimonat, Di-(dodecylphenyl)-iodoniumtriflat, Diphenyliodoniumbisulfat, 4,4'-Dichlorodiphenyliodoniumbisulfat, 4,4'-Dibromodiphenyliodoniumbisulfat, 3,3'-Dinitrodiphenyliodoniumbisulfat, 4,4'-Dimethyldiphenyliodoniumbisulfat, 4,4'-Bis-succinimidodiphenyliodoniumbisulfat, 3-Nitrodiphenyliodoniumbisulfat, 4,4'-Dimethoxydiphenyliodoniumbisulfat, Bis-(dodecylphenyl)-iodoniumtetrakis-(pentafluorophenyl)-borat, (4-Octyloxyphenyl)-phenyliodoniumtetrakis-(3,5-bis-trifluoromethylphenyl) borate and (tolylcumyl) iodonium tetrakis-(pentafluorophenyl) borate, and ferrocenium salts (see, for example, EP 542 716 B1) such as η5-(2,4-cyclopentadien-1-yl)-[(1,2,3,4,5,6,9)-(1-methylethyl)benzene]-iron. ,

[0077] Photolatent bases are also described in the paper "Photolatent bases: new catalysts for UV-curing of coatings" by J. Studer et al., presented at the Radtech e5: UV & EB Technology Conference 2006 (RadTech International, NA, April 23-26, 2006, Lakeside Center at McCormick Place - Chicago, IL). Examples of photolatent bases mentioned therein include ammonium salts of phenylglyoxylates, benzhydrylammonium salts, N-benzophenonemethyl-tri-N-alkylammonium salts, amine imide derivatives, α-ammonium acetophenone salts, and N-methlynifedipine. Further examples of photolatent bases can be found in "Coatings & Inks - Photoinitiators Part 3: What's New or May Be Coming" (Gordon Bradley, January 24).2007) and in the US patents US 6,489,374, US 6,087,070, US 20040242867 and US 20030212164 cited therein, such as 4-(ortho-nitrophenyl)dihydropyridine, quaternary organoboron photoinitiators, α-aminoacetophenones and tetra- or tri-arylalkyl borates of α-ammonium alkenes, iminium alkenes or amidinium alkenes as well as compounds releasing DBN (1,5-diazabicyclo[4.3.0]non-5-ene) under UV light.

[0078] Other activatable catalysts are known from nano- or microencapsulation methods known to those skilled in the art and are described in detail in "Encapsulation Nanotechnologies," edited by Vikas Mittal, Wiley. Typical release mechanisms are described there in Chapter 10.8.2.

[0079] Suitable adhesive resins that may be optionally included are adhesive resins such as those known to the person skilled in the art, for example from Satas.

[0080] Particularly advantageously, the pressure-sensitive adhesive contains at least one type of a preferably at least partially hydrogenated adhesive resin, advantageously those which are compatible with the elastomer component or, if a copolymer composed of hard and soft blocks is used, mainly with the soft block (soft resins).

[0081] It is advantageous if the corresponding adhesive resin has a softening temperature measured using the ring and ball method of greater than 25 °C. It is also advantageous if at least one type of adhesive resin with a softening temperature of less than 20 °C is used. This allows, if necessary, both the adhesive properties and the flow behavior on the bonding substrate to be fine-tuned.

[0082] For relatively non-polar elastomers, partially or fully hydrogenated resins based on rosin and rosin derivatives, hydrogenated polymers of dicyclopentadiene, partially, selectively, or fully hydrogenated hydrocarbon resins based on C 5 , C 5 / C 9 , or C 9 monomer streams, polyterpene resins based on α-pinene and / or β-pinene and / or δ-limonene and / or Δ 3 -carene, and hydrogenated polymers of preferably pure C 8 and C 9 aromatics can advantageously be used as resins in the pressure-sensitive adhesive. The aforementioned adhesive resins can be used alone or in mixtures.

[0083] Both solid and liquid resins can be used at room temperature. To ensure high aging and UV stability, hydrogenated resins with a degree of hydrogenation of at least 90%, preferably at least 95%, are preferred.

[0084] Optionally included reactive resins, also referred to as crosslinkable components, can in principle be used as any reactive constituents known to those skilled in the art in the field of pressure-sensitive adhesives or reactive adhesives, which form crosslinking macromolecules in a build-up reaction, as described, for example, in Gerd Habenicht: Kleben - Grundlagen, Technologien, Anwendungen (Adhesives - Fundamentals, Technologies, Applications), 6th edition, Springer, 2009. These include, for example, constituents that form epoxides, polyesters, polyethers, polyurethanes, phenolic resins, cresol- or novolak-based polymers, polysulfides, or acrylic polymers (acrylic, methacrylic).

[0085] The structure and chemical nature of the crosslinkable components are not critical as long as they are at least partially miscible with the elastomer phase and the build-up reaction can be carried out under conditions, in particular with regard to the temperatures used, type of catalysts used and the like, which do not lead to any significant impairment and / or decomposition of the elastomer phase.

[0086] The reactive resin preferably consists of a cyclic ether and is suitable for radiation-chemical and optionally thermal crosslinking with a softening temperature of less than 40 °C, preferably less than 20 °C.

[0087] Reactive resins based on cyclic ethers are primarily epoxides, i.e., compounds containing at least one oxirane group, or oxetanes. They can be aromatic or, in particular, aliphatic or cycloaliphatic in nature.

[0088] Usable reactive resins can be monofunctional, difunctional, trifunctional, tetrafunctional or higher functional up to polyfunctional, where the functionality refers to the cyclic ether group.

[0089] Examples, without wishing to be limited, are 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate (EEC) and derivatives, dicyclopendadiene dioxide and derivatives, 3-ethyl-3-oxetanemethanol and derivatives, 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, higher 1,n-alkanediglycidyl ethers and derivatives, bis-[(3,4-epoxycyclohexyl)methyl]-adipate and derivatives, vinylcyclohexyl dioxide and derivatives, 1,4-cyclohexanedimethanol bis-(3,4-epoxycyclohexanecarboxylate) and Derivatives, 4,5-epoxytetrahydrophthalic acid diglycidyl ester and derivatives, bis-[1-ethyl(3-oxetanyl)methyl] ether and derivatives, pentaerythritol tetraglycidyl ether and derivatives, bisphenol A diglycidyl 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-oxabicyclo; spiro[1,3-dioxane-5,3'-[7]oxabicyclo[4.1.0]-heptane], 1,4-bis((2,3-epoxypropoxy)methyl)cyclohexane.,

[0090] Reactive resins based on cyclohexyl epoxy, such as 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate (EEC) and derivatives as well as bis-[(3,4-epoxycyclohexyl)methyl]-adipate and derivatives, are particularly suitable for cationic curing.

[0091] Reactive resins can be used in their monomeric or dimeric, trimeric, etc., up to their oligomeric form.

[0092] Mixtures of reactive resins with each other but also with other coreactive compounds such as alcohols (monofunctional or polyfunctional) or vinyl ethers (monofunctional or polyfunctional) are also possible.

[0093] The adhesive composition of the invention is particularly preferably pressure-sensitive. This allows for particularly good handling, since the adhesive composition adheres to the area to be bonded even before crosslinking.

[0094] Pressure-sensitive adhesives (PSAs) are adhesives that allow for a permanent bond with the substrate even under relatively light pressure and can be removed from the substrate after use, leaving essentially no residue. Pressure-sensitive adhesives (PSAs) are permanently tacky at room temperature, meaning they have a sufficiently low viscosity and high tackiness, allowing them to wet the surface of the substrate even under light pressure. The bondability of such adhesives is based on their adhesive properties, and their removability on their cohesive properties. Various materials can be used as the basis for PSAs.

[0095] The present invention further relates to an adhesive tape coated on one or both sides with the adhesive composition of the invention. The adhesive tape can also be a transfer adhesive tape. An adhesive tape enables particularly simple and precise bonding and is therefore particularly suitable. Finally, the present invention relates to the use of the adhesive composition of the invention or the adhesive tape of the invention as a sealant, in particular for encapsulating structures in organic electronics. As explained above, it is of paramount importance in organic electronics that the components must be protected from water (vapor). Due to their very good barrier properties, the adhesive compositions or adhesive tapes of the invention are able to provide appropriate protection.Due to the high transparency and the low damage to the electronics to be encapsulated, the adhesive composition according to the invention and the adhesive tape according to the invention are suitable not only for edge encapsulation but also, in particular, for full-surface encapsulation of organic electronics.

[0096] Finally, the present invention relates to a method for applying an adhesive or an adhesive tape with an adhesive of an adhesive according to the invention or an adhesive tape according to the invention, which method comprises the steps Applying the adhesive or adhesive tape to the object to be bonded and activating the getter material by means of an external stimulus.

[0097] This process makes it possible for the barrier effect of an adhesive or tape to only unfold when it is actually needed—that is, when it encapsulates or covers an object to be protected. Only at this point does the getter become active as a water scavenger. Since the getter function is not activated beforehand, the getter is not consumed during upstream storage or transport.

[0098] The general term "adhesive tape" encompasses a carrier material coated on one or both sides with a (pressure-sensitive) adhesive. The carrier material encompasses all flat structures, for example, films or film sections extended in two dimensions, tapes with extended length and limited width, tape sections, die-cuts (for example, in the form of borders or boundaries of an (opto-)electronic arrangement), multilayer arrangements, and the like. A wide variety of carriers, such as films, fabrics, nonwovens, and papers, can be combined with the adhesives for various applications. Furthermore, the term "adhesive tape" also encompasses so-called "transfer adhesive tapes," i.e., adhesive tapes without a carrier. Rather, with a transfer adhesive tape, the adhesive is applied between flexible liners provided with a release layer and / or having anti-adhesive properties prior to application.For application, one liner is typically removed first, the adhesive is applied, and then the second liner is removed. The adhesive can then be used directly to bond two surfaces in (opto-)electronic devices.

[0099] However, adhesive tapes are also possible that use a single, double-sided separating liner instead of two. The adhesive tape strip is then covered on its upper side with one side of a double-sided separating liner, and its underside with the back of the double-sided separating liner, particularly on an adjacent wrap on a bale or roll.

[0100] In the present case, polymer films, film composites, or films or film composites provided with organic and / or inorganic layers are preferably used as the carrier material for an adhesive tape. Such films / film composites can consist of all common plastics used in film production. Examples include, but are not limited to: polyethylene, polypropylene—in particular oriented polypropylene produced by mono- or biaxial stretching (OPP), cyclic olefin copolymers (COC), polyvinyl chloride (PVC), polyester—in particular polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), ethylene-vinyl alcohol (EVOH), polyvinylidene chloride (PVDC), polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), polycarbonate (PC), polyamide (PA), polyethersulfone (PES), or polyimide (PI).

[0101] Polyester films have the advantage of providing temperature stability and increased mechanical stability. Therefore, a carrier layer in a liner according to the invention particularly preferably consists of a polyester film, for example, biaxially oriented polyethylene terephthalate.

[0102] In a preferred embodiment, the carrier material also contains a barrier function against one or more specific permeate(s), in particular against water vapor and oxygen. Such a barrier function can consist of organic or inorganic materials. Carrier materials with a barrier function are described in detail in EP 2 078 608 A1.

[0103] The carrier material particularly preferably contains at least one inorganic barrier layer. Particularly suitable inorganic barrier layers are metals deposited in a vacuum (for example, by evaporation, CVD, PVD, PECVD) or under atmospheric pressure (for example, by atmospheric plasma, reactive corona discharge, or flame pyrolysis), such as aluminum, silver, gold, nickel, or, in particular, metal compounds such as metal oxides, nitrides, or hydronitrides, for example, oxides or nitrides of silicon, boron, aluminum, zirconium, hafnium, tellurium, or indium tin oxide (ITO). Layers of the aforementioned variants doped with other elements are also suitable.

[0104] In the case of double-sided (self-)adhesive tapes, adhesives according to the invention of the same or different types and / or of the same or different layer thicknesses can be used as the upper and lower layers. The carrier can be pretreated on one or both sides according to the state of the art, for example to improve the anchoring of the adhesive. Likewise, one or both sides can be provided with a functional layer that can act, for example, as a barrier layer. The pressure-sensitive adhesive layers can optionally be covered with release papers or release films. Alternatively, only one adhesive layer can be covered with a double-sided release liner.

[0105] In one variant, the double-sided (self-)adhesive tape contains an adhesive composition according to the invention as well as any other adhesive composition, for example one which adheres particularly well to a covering substrate or which exhibits particularly good repositionability.

[0106] The thickness of the pressure-sensitive adhesive, which is present either as a transfer adhesive tape or coated on a flat structure, is preferably between 1 µm and 2000 µm, more preferably between 5 µm and 500 µm and particularly preferably between about 12 µm and 250 µm.

[0107] Layer thicknesses between 50 µm and 150 µm are used when improved adhesion to the substrate and / or a dampening effect is required.

[0108] Layer thicknesses between 1 µm and 50 µm reduce the amount of material used. However, this results in a reduction in adhesion to the substrate.

[0109] For double-sided adhesive tapes, the thickness of the individual pressure-sensitive adhesive layer(s) is preferably between 1 µm and 2000 µm, more preferably between 5 µm and 500 µm, and particularly preferably between approximately 12 µm and 250 µm. If a second adhesive is used in double-sided adhesive tapes in addition to the one according to the invention, it may also be advantageous if its thickness is above 150 µm.

[0110] Adhesive tapes coated with adhesive on one or both sides are usually wound into a roll in the shape of an Archimedean spiral at the end of the manufacturing process. To prevent the adhesives from coming into contact with each other in the case of double-sided adhesive tapes, or to prevent the adhesive from sticking to the carrier in the case of single-sided adhesive tapes, the adhesive tapes are covered with a release liner (also known as a release liner) before winding, which is wound up together with the adhesive tape. Such release liners are known to those skilled in the art as liners or release liners. In addition to covering single- or double-sided adhesive tapes, liners are also used to cover pure adhesives (transfer adhesive tape) and adhesive tape sections (e.g., labels).

[0111] Another main claim relates to a method for protecting an organic electrical device arranged on a substrate, wherein a cover is applied to the electronic device such that the electronic device is at least partially covered by the cover. Furthermore, the cover is bonded at least partially to the substrate and / or to the electronic device, wherein the bonding is achieved by means of at least one layer of an adhesive. The adhesive layer is present, in particular, as a layer of an adhesive tape.

[0112] The method according to the invention can advantageously be carried out in such a way that the (pressure-sensitive) adhesive layer, optionally as a component of a double-sided adhesive tape comprising further layers, is first applied to the substrate and / or the electronic assembly, and in a subsequent step, the cover is applied. In a further advantageous procedure, the (pressure-sensitive) adhesive layer, optionally as a component of a double-sided adhesive tape comprising further layers, and the cover are applied together to the substrate and / or the electronic assembly.

[0113] In the method according to the invention, the transfer adhesive tape can thus first be bonded to the substrate or the electronic assembly, or first to the cover. However, it is preferred to first bond the transfer adhesive tape to the cover, since this allows an assembly of the electronic functional unit to be prefabricated independently of the electronic assembly and laminated as a whole.

[0114] Advantageously, the method according to the invention can be carried out in such a way that the cover and / or the (pressure-sensitive) adhesive layer, in particular as a transfer adhesive tape, completely cover the electronic arrangement, since the light-scattering effect then affects the entire surface of the arrangement.

[0115] The full-surface lamination of the transfer adhesive tape over the electronic assembly also eliminates the effect of harmful permeates potentially trapped in the gas space of a merely edge-encapsulated assembly, as there is no gas space.

[0116] The method according to the invention is preferably carried out in such a way that a region of the substrate around the electronic arrangement is also completely or partially covered by the cover, wherein the adhesive tape for bonding can cover the electronic arrangement over its entire area and preferably also covers a region of the substrate around the electronic arrangement, preferably the same area as the cover - or can be applied over part of the area, for example in the shape of a frame around the electrical arrangement - preferably in the area that is also covered by the cover - and optionally additionally in an edge area on the electronic arrangement.

[0117] A further subject matter of the invention is an (opto-)electronic arrangement comprising at least one (opto-)electronic structure and a layer of an adhesive according to the invention, wherein the adhesive layer covers the (opto-)electronic structure over its entire surface.

[0118] Further details, features and advantages of the present invention are explained in more detail below using preferred embodiments. The drawing shows

[0119] Fig. 3 a schematic representation of an (opto-)electronic arrangement according to the state of the art,

[0120] Fig. 4 a first (opto-)electronic arrangement according to the invention in a schematic representation,

[0121] Fig. 5 a second (opto-)electronic arrangement according to the invention in a schematic representation.

[0122] Fig. 3shows a first embodiment of an organic electronic device 1 according to the prior art. This device 1 comprises a substrate 2 on which an electronic structure 3 is arranged. The substrate 2 itself is designed as a barrier for permeates and thus forms part of the encapsulation of the electronic structure 3. Above the electronic structure 3, in this case also spatially spaced from it, a further cover 4 designed as a barrier is arranged.

[0123] In order to encapsulate the electronic structure 3 laterally and simultaneously connect the cover 4 to the electronic arrangement 1, an adhesive 5 is provided circumferentially next to the electronic structure 3 on the substrate 2. It is irrelevant whether the adhesive was first bonded to the substrate 2 or first to the cover 4. The adhesive 5 connects the cover 4 to the substrate 2. By virtue of a correspondingly thick design, the adhesive 5 also enables the spacing of the cover 4 from the electronic structure 3.

[0124] Adhesive 5 is a state-of-the-art adhesive, i.e., an adhesive with a high permeation barrier that can also be filled to a high degree with getter material. The transparency of the adhesive is not relevant in this structure.

[0125] In the present case, a transfer adhesive tape would be provided in the form of a die-cut, which, due to its delicate geometry, is more difficult to handle than a transfer adhesive tape that is essentially applied over the entire surface.

[0126] Fig. 4shows an inventive embodiment of an (opto-)electronic arrangement 1. Again, an electronic structure 3 is shown, which is arranged on a substrate 2 and encapsulated from below by the substrate 2. The adhesive according to the invention, for example in the form of an adhesive transfer tape 6, is arranged above and to the side of the electronic structure over the entire surface. The electronic structure 3 is thus completely encapsulated from above by the adhesive transfer tape 6. A cover 4 is then applied to the adhesive transfer tape 6. The adhesive transfer tape 6 is one based on the adhesive transfer tape according to the invention as described above in general terms and explained in more detail below in exemplary embodiments. In the embodiment shown, the adhesive transfer tape consists of only one layer of an adhesive according to the invention.

[0127] In contrast to the previous embodiment, the cover 4 does not necessarily have to meet the high barrier requirements, since when the electronic assembly is fully covered by the transfer adhesive tape, the barrier is already provided by the adhesive. The cover 4 can, for example, merely perform a mechanical protective function, but it can also be additionally provided as a permeation barrier.

[0128] Fig. 5shows an alternative embodiment of an (opto-)electronic arrangement 1. In contrast to the previous embodiments, two transfer adhesive tapes 6a, b are now provided, which are identical in the present case, but can also be different. The first transfer adhesive tape 6a is arranged over the entire surface of the substrate 2. The electronic structure 3 is provided on the transfer adhesive tape 6a and is fixed by the transfer adhesive tape 6a. The composite of transfer adhesive tape 6a and electronic structure 3 is then covered over its entire surface with the further transfer adhesive tape 6b, so that the electronic structure 3 is encapsulated on all sides by the transfer adhesive tapes 6a, b. The cover 4 is again provided above the transfer adhesive tape 6b.

[0129] In this embodiment, neither the substrate 2 nor the cover 4 necessarily have to have barrier properties. However, they can still be provided to further restrict the permeation of permeates to the electronic structure 3.

[0130] In particular with regard to the Fig. 4 and 5Please note that these are schematic representations. In particular, it is not apparent from the representations that the transfer adhesive tape here and preferably in each case has a homogeneous layer thickness. At the transition to the electronic structure, therefore, no sharp edge forms, as it appears in the representation, but rather the transition is fluid and, instead, small unfilled or gas-filled areas can remain. If necessary, however, an adaptation to the substrate can also take place, particularly if the application is carried out under vacuum. In addition, the adhesive is compressed to different degrees locally, so that a certain compensation of the height difference at the edge structures can occur through flow processes. The dimensions shown are also not to scale but serve only to improve the illustration.In particular, the electronic structure itself is usually relatively flat (often less than 1 µm thick).

[0131] Direct contact between the adhesive and the electronic assembly is not mandatory. Additional layers can also be arranged in between, such as a thin-film encapsulation of the electronic assembly or barrier films.

[0132] The thickness of the transfer adhesive tape can range from any conventional thickness, from approximately 1 µm to 3000 µm. A thickness between 25 and 100 µm is preferred, as adhesive strength and handling properties are particularly favorable in this range. Another preferred thickness range is 3 to 25 µm, as the amount of substances permeating through the adhesive joint can be kept low in an encapsulation application simply due to the small cross-sectional area of ​​the adhesive joint.

[0133] To produce a transfer adhesive tape according to the invention, the adhesive tape carrier or liner is coated or printed on one side with the adhesive according to the invention from a solution or dispersion or 100% (e.g., melt) form, or the adhesive tape is produced by (co-)extrusion. Alternatively, production is possible by transferring an adhesive layer according to the invention by laminating it onto a carrier material or liner. The adhesive layer can be crosslinked by heat or high-energy radiation.

[0134] This manufacturing process preferably takes place in an environment where the specific permeate is present in low concentrations or almost completely absent. An example would be a relative humidity of less than 30%, preferably less than 15%. Examples Measurement methods Determination of breakthrough time (lifetime test)

[0135] A calcium test was used as a measure for determining the lifetime of an electronic assembly. This test is described in the Figure 1shown. For this purpose, a 10 × 10 mm 2< large, thin calcium layer 23 is deposited in a vacuum onto a glass plate 21 and then stored under a nitrogen atmosphere. The thickness of the calcium layer 23 is approximately 100 nm. To encapsulate the calcium layer 23, an adhesive tape (23 × 23 mm 2< ) with the adhesive 22 to be tested and a thin glass pane 24 (35 µm, Schott) as the carrier material are used. For stabilization, the thin glass pane was laminated with a 100 µm thick PET film 26 using a 50 µm thick transfer tape 25 of an optically highly transparent acrylic pressure-sensitive adhesive. The adhesive 22 is applied to the glass plate 21 in such a way that the adhesive 22 covers the calcium mirror 23 with an all-round overhang of 6.5 mm (AA). Due to the impermeable glass carrier 24, only the permeation through the pressure-sensitive adhesive or along the interfaces is determined.

[0136] The test is based on the reaction of calcium with water vapor and oxygen, as described, for example, by AG Erlat et al. in "47th Annual Technical Conference Proceedings - Society of Vacuum Coaters," 2004, pages 654 to 659, and by ME Gross et al. in "46th Annual Technical Conference Proceedings - Society of Vacuum Coaters," 2003, pages 89 to 92. The light transmission of the calcium layer is monitored, which increases due to the conversion to calcium hydroxide and calcium oxide. In the described test setup, this occurs from the edge, so that the visible surface of the calcium mirror is reduced. The time until the light absorption of the calcium mirror is halved is referred to as the lifetime. The method records both the degradation of the surface of the calcium mirror from the edge and through localized degradation within the surface, as well as the homogeneous reduction in the layer thickness of the calcium mirror through full-surface degradation.

[0137] The measurement conditions were 60 °C and 90% relative humidity. The samples were bonded over the entire surface and without bubbles using a pressure-sensitive adhesive layer thickness of 50 µm. The degradation of the Ca level is monitored via transmission measurements. The lag time is defined as the time required for moisture to travel the distance to the Ca (see [Fig. Fig.2 ). Until this time is reached at 60°C 90% RH, the transmission of the Ca level changes only marginally and at 85°C 85% RH a little. Permeability to water vapor

[0138] Water vapor permeability (WVTR) is determined according to ASTM F-1249. The pressure-sensitive adhesive is applied in a layer thickness of 50 µm to a highly permeable polysulfone membrane (available from Sartorius), which itself does not contribute to the permeation barrier. Water vapor permeability is determined at 37.5 °C and a relative humidity of 90% using a Mocon OX-Tran 2 / 21 measuring device. Molecular weight

[0139] The number-average molecular weights M n and the weight-average molecular weights M w were determined by gel permeation chromatography (GPC). THF (tetrahydrofuran) with 0.1 vol.% trifluoroacetic acid was used as the eluent. The measurement was carried out at 25 °C. A PSS-SDV, 5 µ, 10 3 < Å, ID 8.0 mm × 50 mm, was used as the precolumn. The columns used for separation were PSS-SDV, 5 µ, 10 3 <, 10 5 <, and 10 6 <, each with ID 8.0 mm × 300 mm. The sample concentration was 4 g / L, and the flow rate was 1.0 ml per minute. The measurement was carried out against polystyrene standards. MMAP and DACP

[0140] MMAP is the mixed methylcyclohexane-aniline cloud point, determined using a modified ASTM C 611 method. Methylcyclohexane is substituted for the heptane used in the standard test method. The method uses resin / aniline / methylcyclohexane in a ratio of 1 / 2 / 1 (5 g / 10 ml / 5 ml), and the cloud point is determined by cooling a heated, clear mixture of the three components until complete turbidity just occurs.

[0141] The DACP is the diacetone cloud point and is determined by cooling a heated solution of 5 g resin, 5 g xylene and 5 g diacetone alcohol to the point at which the solution becomes cloudy. Ring & Ball softening temperature:

[0142] The adhesive resin softening temperature is determined using the relevant methodology known as Ring and Ball, standardized according to ASTM E28.

[0143] A Herzog HRB 754 ring-and-ball machine is used to determine the resin's softening temperature. Resin samples are first finely ground. The resulting powder is poured into a brass cylinder with a bottom opening (inner diameter at the top of the cylinder: 20 mm, diameter of the bottom opening of the cylinder: 16 mm, height of the cylinder: 6 mm) and melted on a hot table. The filling quantity is selected so that the resin completely fills the cylinder after melting.

[0144] The resulting test specimen, complete with cylinder, is placed in the test holder of the HRB 754. Glycerol is used to fill the temperature control bath if the adhesive resin softening temperature is between 50 °C and 150 °C. At lower adhesive resin softening temperatures, a water bath can also be used. The test spheres have a diameter of 9.5 mm and weigh 3.5 g. According to the HRB 754 procedure, the sphere is positioned above the test specimen in the temperature control bath and placed on the test specimen. A collecting plate is located 25 mm below the cylinder base, and a light barrier is located 2 mm above this. During the measurement process, the temperature is increased by 5 °C / min. In the temperature range of the adhesive resin softening temperature, the sphere begins to move through the bottom opening of the cylinder until it finally comes to rest on the collecting plate.In this position, it is detected by the light barrier, and the temperature of the tempering bath is recorded at this time. A double determination is performed. The adhesive resin softening temperature is the average of the two individual measurements. Adhesive layers:

[0145] To produce adhesive layers, various adhesives were applied from a solution to a conventional liner (siliconized polyester film) using a laboratory coating device and dried. The adhesive layer thickness after drying was 50±5 µm. Drying was carried out first at room temperature for 10 minutes and then at 120 °C for 10 minutes in a laboratory drying cabinet. Immediately after drying, the dried adhesive layers were laminated to a second liner (siliconized polyester film with lower release force) on the open side. Raw materials used:

[0146] Sibstar 62M SiBS (polystyrene-block-polyisobutylene block copolymer) from Kaneka with 20 wt.% block polystyrene. Also contains some diblock copolymers. Tuftec P 1500 SBBS with 30% block polystyrene content from Asahi The SBBS contained approximately 68% diblock content. HBE-100 hydrogenated bisphenol A diglycidyl ether from ECEM Escorez 5300 a fully hydrogenated hydrocarbon resin from Exxon. (Ring and Ball 105 °C, DACP = 71, MMAP = 72) Escorez 5600 Hydrogenated KW resin with a softening point of 100°C from Exxon. Ondina G 17 White oil made from paraffinic and naphthenic components from Shell Polyacrylate Acrylate copolymer of 2-hydroxyethyl acrylate, 2-ethylhexyl acrylate and C-17 acrylate, M n = 884000 g / mol Glycidoxypropyltriethoxysilane [4-(2-hydroxytetradecyloxy)phenyl]phenyliodonium hexafluoroantimonate Triethoxysilane with glycidyl epoxide group cationic photoinitiator from Sigma-Aldrich The photoinitiator has an absorption maximum in the range 320 nm to 360 nm and was present as a 50 wt.% solution in propylene carbonate Titanium(IV) isopropoxide Catalyst for the hydrolysis of alkoxysilanes (Sigma-Aldrich)

[0147] A polystyrene-block-polyisobutylene block copolymer from Kaneka was selected as the copolymer. The styrene content of the total polymer is 20 wt%. Sibstar 62M was used. The molecular weight Mw is 60,000 g / mol. The glass transition temperature of the polystyrene blocks was 100 °C and that of the polyisobutylene blocks was -60 °C. Escorez 5300 (ring and ball 105 °C, DACP = 71, MMAP = 72) from Exxon, a fully hydrogenated hydrocarbon resin, and Escorez 5600 (softening point 100 °C), a hydrogenated hydrocarbon resin, were used as the adhesive resin. These raw materials and, if applicable, the alkoxysilane were dissolved in a mixture of toluene (300 g), acetone (150 g) and special boiling point spirit 60 / 95 (550 g) to form a 50 wt.% solution.

[0148] A catalyst was then added to the solution. The catalyst was present as a 50 wt. % solution in propylene carbonate. The photolatent catalyst exhibits an absorption maximum in the range 320 nm to 360 nm.

[0149] The exact composition of the individual examples V1 and V2 or K1 and K2 can be found in Table 1. Table 1: Example: K1 K2 V1 V2 parts by weight parts by weight parts by weight parts by weight Sibstar 62M 37,5 HBE-100 20 20 Escorez 5600 100 100 Escorez 5300 37,5 Ondina G17 25 25 Tuftec P 1500 100 100 Polyacrylate - 75 Glycidoxypropyltri-ethoxysilane 5 Triethoxyoctylsilane 10 5 Titanium(IV) isopropoxide 0,3 [4-(2-hydroxytetradecyloxy)phenyl]phenyliodonium hexafluoroantimonate 0,3 0,1 0,1

[0150] The samples were placed in a glove box. A portion of the samples was laminated onto a Ca-evaporated glass substrate using a rubber roller to ensure bubble-free adhesion. The second PET liner was then removed and a layer of thin glass was laminated onto it. This sample was used for the durability test.

[0151] The results of the moisture permeation measurement of the masses as well as the determined water breakthrough times in the Ca test before and after activation of the catalyst and thus of the getter as well as after the samples were exposed to water are shown in Table 2. Table 2: K1 K2 V1 V2 WVTR / gm -2< d -1< 33 12 34 678 lag time 1< / h 10 0 150 0 lag time 2< / h 150 470 150 0 lag time 3< / h 145 480 0 0 1< : Fresh adhesive tape (catalyst not activated by UV light), Ca test at 60°C / 90% RH. 2< : Fresh adhesive tape, catalyst activation with UV light, Ca test at 60°C / 90% RH. 3< : After the sample was exposed to H 2 O for 1 day at 23°C / 50% RH, dried again in an inert atmosphere, catalyst activation with UV light. Ca test at 60°C / 90% RH.

[0152] For Comparative Example C1, a catalyst not according to the invention, i.e., a non-switchable catalyst, was used. The sample exhibits a certain lag time that does not change upon exposure to UV light. The getter is not switchable. In Example C1 according to the invention, the lag time changes significantly. In Example C1, the lag time after activation of the catalyst, and thus of the getter, by UV radiation is 15 times higher than before activation. Example C2 is an example of combined activation of the getter and curing of the reactive resin. Before activation / curing, the adhesive exhibits no lag time. Activation / curing achieves a long lag time.

[0153] When the non-activated samples were exposed to humid air for one day, the non-inventive sample V1 showed that the getter was consumed and had already reacted with the water, so that the lag time dropped to zero. In contrast, in the inventive samples K1 and K2, the non-activated getter had not reacted with the water contained in the humid air during the one-day exposure. The lag time of the samples was essentially identical to that of a sample not exposed to humid air. Therefore, although the samples were exposed to water vapor, this had no effect on their effectiveness as getters, since the getter function had not yet been activated.

[0154] Comparative example V2 shows that a sample with a high WVTR value has no measurable lag time.

Claims

1. Adhesive, where the adhesive is a barrier adhesive, the adhesive base of which, in the presence of a reactive resin after curing thereof, has a water vapour permeation rate of less than 100 g / m2d, determined to ASTM F-1249 at 37.5°C and a relative humidity of 90%, comprising a getter material and optionally a solvent, characterized in that the adhesive comprises a catalyst for the reaction of the getter material with a permeate, which is activatable by means of an external stimulus, where the getter material is at least one compound selected from the group comprising ethoxysilanes and where the permeate is water.

2. Adhesive according to Claim 1, characterized in that the getter is present in an amount of at least 2% by weight, preferably at least 3% by weight, especially at least 5% by weight.

3. Adhesive according to at least one of Claims 1 and 2, characterized in that the amount of catalyst is less than 5% by weight, preferably less than 2% by weight, especially less than 1% by weight.

4. Adhesive according to at least one of Claims 1 to 3, characterized in that the external stimulus is UV radiation, a temperature change, microwave radiation or visible light.

5. Adhesive according to at least one of Claims 1 to 4, characterized in that the catalyst activatable by an external stimulus is a latent acid or a latent base.

6. Adhesive according to at least one of Claims 1 to 5, characterized in that the adhesive comprises an adhesive base composed of - at least one polymer, especially elastomer, and - at least one tackifying resin.

7. Adhesive according to at least one of Claims 1 to 6, characterized in that the adhesive base further comprises at least one reactive resin having at least one curable group.

8. Adhesive according to Claim 6 or 7, characterized in that the adhesive base, if a reactive resin is present, has a water vapour permeation rate after curing of less than 50 g / m2d, especially less than 15 g / m2d.

9. Adhesive according to Claim 9, characterized in that the ethoxysilane additionally comprises at least one polymerizable group.

10. Adhesive according to Claim 9, characterized in that the polymerizable group is polymerizable with those of the optional reactive resin, especially characterized in that the polymerizable group is the same as that in the reactive resin.

11. Adhesive according to Claim 7, characterized in that the at least one curable group is at least one group selected from cyclic ether, vinyl, acrylate, methacrylate, hydroxyl, amino and isocyanate.

12. Adhesive according to at least one of Claims 1 to 11, characterized in that the adhesive is a pressure-sensitive adhesive.

13. Adhesive tape comprising an adhesive according to any of Claims 1 to 12.

14. Use of the adhesive according to any of Claims 1 to 12 or of the adhesive tape according to Claim 13 for encapsulation of assemblies in organic electronics.

15. Method for applying an adhesive according to any of Claims 1 to 12, or an adhesive tape according to Claim 13, comprising the steps of - applying the adhesive or the adhesive tape to the article to be bonded; - activating the getter material by means of an external stimulus.

16. Method according to Claim 15, characterized in that the adhesive comprises a reactive resin and the external stimulus induces not only the activation of the getter material but also the curing of the adhesive or the adhesive tape.

17. Method for protecting an organic electronic arrangement disposed on a substrate, wherein a cover is applied to the electronic arrangement in such a way that the electronic arrangement is at least partly covered by the cover, wherein the cover is additionally bonded over at least part of the area on the substrate and / or on the electronic arrangement, wherein the bonding is brought about by means of at least one layer of an adhesive according to at least one of the preceding claims.

18. Method according to Claim 17, characterized in that the adhesive takes the form of a layer of an adhesive tape.

19. Method according to at least one of Claims 17 and 18, characterized in that the adhesive layer, optionally as a constituent of a double-sided adhesive tape comprising further layers, is applied first, and in a subsequent step the cover is applied to the substrate and / or the electronic arrangement.

20. Method according to at least one of Claims 17 to 19, characterized in that the adhesive layer and the cover are applied together to the substrate and / or the electronic arrangement.

21. Method according to at least one of Claims 17 to 20, characterized in that the cover fully covers the electronic arrangement.

22. Method according to at least one of Claims 17 to 20, characterized in that a region of the substrate around the electronic arrangement is also wholly or partly covered by the cover.