Curable composition, method for bonding, casting or coating substrates, and use of the composition

Abstract

The invention relates to a composition which can be fixed by actinic radiation and cured by heat, the composition comprising: (A) an at least bifunctional, passivated, and solid isocyanate; (B) an isocyanate-reactive component which comprises at least one liquid hybrid compound (B1) which, in addition to at least one isocyanate-reactive group, contains at least one radically curable group, the hybrid compound (B1) having a molar mass of at least 400 g / mol; and (C) an initiator system for radical polymerisation, which comprises a first initiator (C1) and a second initiator (C2), the first initiator (C1) being a radical photoinitiator and the second initiator (C2) being a radical initiator for heat curing. The invention also relates to a method for bonding, casting and / or coating substrates, and to a use of a curable composition.

Description

[0001] DELO Industrie Klebstoffe GmbH & Co. KGaA Our reference: D 3336 WO WS / TH Curable compound, method for joining, coating or potting substrates and use of the compound FIELD OF THE INVENTION The present invention relates to a one-component compound based on polyisocyanates which can be fixed with actinic radiation and is curable by heat. Furthermore, the invention relates to a method for joining, coating or potting substrates using the compound and the use of the compound for joining, potting and / or bonding electronic and optoelectronic components. TECHNICAL BACKGROUND Heat-curing compounds based on polyisocyanates and polyamines or polyols are generally known. In order to ensure sufficient storage stability, solid isocyanates which are passivated on their surface and dispersed in a higher molecular weight isocyanate-reactive component can be used.When heat is applied, the surface-passivated polyisocyanate melts, and the adhesive cures. The cured compounds exhibit silicone-like mechanical properties. These include a low glass transition temperature as well as high flexibility and durability. This property profile is advantageous for chip, sensor, and loudspeaker bonding, as well as for applications in the camera sector. Additional radiation-curing components enable rapid fixation of the compounds and joints, thus allowing for temporally and spatially independent final curing. This allows complex geometries to be fixed quickly and larger quantities to be produced per unit time. However, additional radiation-curing components also result in technical disadvantages, as they can dissolve the surface-passivated polyisocyanates and impair the storage stability of the compounds.In addition, uncured components of the radiation-curable network remain in shadow zones, which adversely affects the properties of the cured adhesive. Suitable curing agents for polyisocyanate formulations are amines, alcohols, or thiols. Liquid and higher-molecular-weight compounds with the aforementioned functional groups, based, for example, on polyolefins, polyesters, or polyethers, are often used as dispersing media. The synthesis of polyetheramines is known and is described, for example, in US Pat. No. 3,654,370 A or US Pat. No. 5,103,062 A. In this process, terminal hydroxyl groups of polyether polyols are usually converted to the analogous amines. WO 2020250154 A1 describes (meth)acrylate-functional crosslinkers for structural bonding.The polyether polyols and polyether polyamines used in the production process are fully reacted with isocyanato(meth)acrylates, among others, to form polyurethane and polyurea compounds before being used in adhesive blends. WO 2021090216 A1 describes hydrophilic (meth)acrylate-functional monomers based on polyetheramines. These are fully reacted with polyfunctional (meth)acrylates in a Michael addition reaction to form secondary and / or tertiary amines. Use as a hybrid-reactive compound is not described. WO 2012121822 A1 describes the use of (meth)acrylates for the synthesis of hybrid polyamines and their use as curing agents for epoxy resins. The (meth)acrylates are used here to extend polyetheramines and polyalkyleneamines. WO 2008076662 A2 uses mono- and higher-functional (meth)acrylates and amines to produce oligomers with defined reactivity towards isocyanates.During the reaction, the (meth)acrylate component is consumed, resulting in products containing predominantly secondary amines. The adhesives are formulated as two-component compositions. Additional fixation or curing by light is not required. Polyetheramines and mixtures thereof can also be used as hardeners for epoxy resins, as described in WO 2018144974 A1. EP 0103323 B1 describes a process for producing solid, surface-passivated polyisocyanates and their use in storage-stable, heat-curable compositions. High-molecular-weight polyols and / or polyamine compounds, as well as low-molecular-weight chain extenders, are described as hardeners. Additional components containing the aforementioned functional groups can optionally be added. EP 0100508 B1 describes heat-curing compositions based on polyisocyanates.Long-chain polyetheramines are used as a liquid medium during the surface passivation of the solid polyisocyanates. During heat curing, these react with the polymer network. EP 3749700 A1 discloses one-component, storage-stable compositions based on surface-passivated polyisocyanates. By adding a radically radiation-curable component and a photoinitiator, the compositions can be fixed by light. It is further proposed to use a hybrid compound that, in addition to a radiation-curable group, has an additional isocyanate-reactive group to connect the light- and heat-curing networks. Disadvantages of these compositions are low light-fixation strength and poor adhesion due to incomplete crosslinking of radically polymerizable components in shadow zones.SUMMARY OF THE INVENTION The object of the present invention is to avoid the disadvantages of the compositions known from the prior art and to provide curable compositions, in particular one-component compositions, based on polyisocyanates, which are characterized in particular by their high light-fixation resistance and reliable curing in shadow zones. This object is achieved according to the invention by a composition according to claim 1. Advantageous embodiments are specified in the subclaims, which can optionally be combined with one another.The composition according to the invention, which can be fixed with actinic radiation and cured by heat, comprises (A) an at least difunctional, passivated and solid isocyanate; and (B) an isocyanate-reactive component comprising at least one liquid hybrid compound which, in addition to at least one isocyanate-reactive group, contains at least one free-radically curable group, the hybrid compound having a molar mass of at least 400 g / mol; and (C) an initiator system for free-radical polymerization comprising a first initiator and a second initiator, the first initiator being a free-radical photoinitiator and the second initiator being a free-radical initiator for heat curing. The curable composition is liquid at room temperature and, after curing, is characterized by high elongation at break and temperature stability.In particular, the cured composition has a modulus of elasticity in the range from 5 MPa to 500 MPa, which remains largely constant over a temperature range of -35 °C to 100 °C. This is also due to the fact that the glass transition temperature of the cured composition is usually -40 °C or lower. Thus, the composition according to the invention is also suitable for applications in which significant temperature fluctuations are to be expected. The molar mass here and below refers to the average molar mass M. n, unless otherwise stated. The use of a hybrid compound links the networks formed by light and heat curing (hereinafter also referred to as the "light network" or "shadow network"). In addition to an isocyanate-reactive group, the hybrid compound has at least one radically curable group that enables light fixation of the curable compound. An additional radical initiator for heat curing enables complete curing of the radically curable groups in shadow zones, thus ensuring homogeneous properties of the cured compound across the entire application range.The additional radical initiator for heat curing allows the advantageous use of other, optionally added to the composition, radically curable monomers without isocyanate-reactive groups to increase light-fixation strength, as these are reliably incorporated into the polymer network in shadow zones during the heat-curing step following light-fixation. Without the addition of the radical initiator for heat curing, non-crosslinked formulation components would remain in shadow zones, resulting in reduced adhesion and undesirable outgassing of the non-crosslinked formulation components from the cured composition. The combination of isocyanate-reactive and radically curable groups in one molecule usually results in components that lack sufficient storage stability or processing time.Surprisingly, it has now been discovered that the advantageous combination of a radically curable group and an isocyanate-reactive group can be realized in a hybrid molecule, enabling the linking of a light and shadow network with simultaneous high adhesion. Furthermore, a sufficiently high light-fixation strength can be achieved with a reduced amount or entirely without the addition of other radically light-curing components. The curable compositions according to the invention are therefore particularly suitable for applications in which the advantageous properties of the cured compositions combined with high light-fixation strength can be advantageously utilized. This property profile is advantageous, for example, for chip, sensor, or loudspeaker bonding.By combining the isocyanate component with radically curable formulation components, it is surprisingly possible to counteract a volume change, in particular a volume expansion, during curing, thereby making it possible to produce adhesives with low expansion or even shrinkage, i.e., a volume decrease. This property is particularly advantageous in optical applications such as the production of LIDAR assemblies or the bonding of lenses or optoelectronic components such as camera modules. The invention further relates to a method for joining, potting, and / or coating substrates using the curable composition according to the invention.A corresponding method for joining, casting, and / or coating substrates using the curable composition according to the invention as described above comprises the following steps: (a) metering the curable composition onto a first substrate; (b) optionally supplying a second substrate to form a substrate composite; (c) fixing the curable composition with actinic radiation; and (d) heat-curing the fixed composition on the substrate and / or in the substrate composite by heating to a temperature of at least 60°C. Light fixation allows the curable composition to be converted into a dimensionally stable state and, in a subsequent process step, finally cured by heat at a separate time.Due to the described control of the volume change, even particularly complex geometries, for example in optical applications, can be reliably fixed by light and cured without undesired stress introduction using the method using the compound according to the invention. The object of the invention is further achieved by the use of the previously described curable compound for joining, encapsulating, and / or bonding electronic and optoelectronic components for the production of camera modules or LIDAR systems. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS The invention is described in detail below and by way of example with reference to preferred embodiments, which, however, are not to be understood in a limiting sense.The following definitions are used in the description: "One-component" or "one-component mass" in the sense of the invention means that the named components of the mass are present together in one packaging unit. Accordingly, the named components of the mass are not stored separately from one another. The masses are considered "processable" if the viscosity of the respective ready-mixed mass increases by less than 25% during storage at room temperature for a period of at least 72 hours. "Liquid" in the sense of the invention means that at 23 °C the loss modulus G'' determined by rheological measurement is greater than the storage modulus G' of the mass in question. "Curing" is defined as a polymerization reaction beyond the gel point. The gel point is the point at which the storage modulus G' becomes equal to the loss modulus G''."At least difunctional" means that the respective compound or mixture of substances has a functionality of at least 2, based on a specific functional group or on several specific functional groups. At least difunctional isocyanates therefore have at least two isocyanate groups (-NCO) in the molecule. "Fixation" or "fixing" refers to the build-up of a strength in the compound above which flow of the compound can no longer occur, or the degree of strength above which joined parts, in particular substrates, can be handled in subsequent processes without destroying the adhesive bond, in particular the substrate bond. "Primary amine" means that the amine is bound to exactly one other hydrocarbon unit. In contrast, "primary alcohol" or "primary thiol" means that the functional group is bound to a primary carbon."Primary carbon" means that the carbon is bonded to exactly one other hydrocarbon unit. Analogous definitions apply to the secondary and tertiary functional groups. Where the indefinite article "a" or "an" is used, this also includes the plural form "one or more" unless expressly excluded. All weight proportions listed below refer to the total weight of the curable composition, unless otherwise stated. The individual components of the curable composition according to the invention, which can be used in particular in the process according to the invention, are described in more detail below.Component (A): Passivated and solid isocyanate The at least difunctional passivated and solid isocyanate (A) is an isocyanate obtained by reacting an at least difunctional and solid isocyanate (A1), hereinafter also referred to as polyisocyanate (A1), and a passivating agent (A2). Polyisocyanate (A1) To provide storage-stable materials, the solid polyisocyanate (A1) is passivated accordingly on its surface. For this purpose, the solid polyisocyanate (A1) is reacted on its surface with the passivating agent (A2). The passivation prevents the reaction of the isocyanate (A1) with other isocyanate-reactive formulation components or slows it down so much that a sufficient processing time and storage stability are ensured. In principle, any at least difunctional isocyanate that has a melting point of, in particular, at least 40 °C can be used as polyisocyanate (A1).The polyisocyanate (A1) preferably has a melting point of at least 60°C. The melting point of the solid polyisocyanate is preferably at most 200°C, particularly preferably at most 180°C. The polyisocyanate (A1) is preferably an aliphatic, cycloaliphatic, heterocyclic, or aromatic polyisocyanate. The polyisocyanate (A1) can be present at least partially, preferably entirely, in dimeric form (uretdione form) or trimeric form (isocyanurate form). Examples of suitable polyisocyanates (A1) are: dimeric 2,4-diisocyanatotoluene, dimeric 4,4'-diisocyanatodiphenylmethane, 3,3'-diisocyanato-4,4'-dimethyl-N,N'-diphenylurea, the isocyanurate of isophorone diisocyanate, 1,4-phenylene diisocyanate, naphthalene-1,5-diisocyanate and addition products of diisocyanates with short-chain diols having 2 to 6 carbon atoms, such as 1,4-butanediol or 1,2-ethanediol.Particular preference is given to dimeric 2,4-diisocyanatotoluene, dimeric 4,4'-diisocyanatodiphenylmethane, 3,3'-diisocyanato-4,4'-dimethyl-N,N'-diphenylurea, and / or the isocyanurate of isophorone diisocyanate. The solid polyisocyanate (A1) is preferably in the form of particles with a volumetric particle diameter d95 of at most 100 µm, preferably at most 40 µm, and particularly preferably at most 10 µm. Passivating agent (A2) The solid polyisocyanate (A1) is preferably reacted on its surface with a passivating agent (A2), as described in EP 0153579 A2, EP 0100508 B1, or EP 3749700 A1.By reacting the solid polyisocyanate (A1) with the passivating agent (A2), a substantially inert shell forms on the surface of the solid polyisocyanate (A1), preventing further reaction of the isocyanate groups underlying the shell until the shell is broken open by the application of heat during the subsequent heat-curing step, so that the composition, in particular a single-component composition, cures. Preferred passivating agents (A2) are compounds from the group of polyamines, amidine and / or guanidine compounds, hydrazines, alkylhydrazines, and / or hydrazide compounds, which react with the isocyanate groups present on the surface of the solid polyisocyanate (A1) to form urea groups.Particular preference is given to using primary aliphatic at least difunctional amines having a molecular weight in the range from 60 to 600 g / mol as passivating agents (A2), and very particular preference is given to using polyetheramines, such as those commercially available, for example, under the name Jeffamine. ® D-400 or Jeffamine ®T-403 are available from Huntsman. For passivation, 0.1 to 25 mol percent of all isocyanate groups present in the solid polyisocyanate (A1) can be reacted with the passivating agent (A2), preferably 0.5 to 15 mol percent, and particularly preferably 1 to 10 mol percent. In a preferred embodiment, the at least difunctional passivated and solid isocyanate (A) is obtained by reacting the solid polyisocyanate (A1), present in the form of micronized particles, with the passivating agent (A2) at a temperature below the melting point of the solid polyisocyanate (A1) in a liquid medium, wherein the liquid medium itself is not a good solvent for the solid polyisocyanate (A1). Higher molecular weight polyols or polyamines with a molecular weight of up to 20,000 g / mol can serve as the liquid medium, and these can themselves be used as isocyanate-reactive component (B) in the curable compositions according to the invention.In this case, the reactivity of the passivating agent (A2) and the liquid medium is selected such that a reaction on the surface of the solid polyisocyanate (A1) essentially occurs with the passivating agent (A2). According to a preferred embodiment, the surface-passivated, solid isocyanate (A) is dispersed. This allows a particularly homogeneously cured composition to be obtained upon application of heat. The solid polyisocyanate (A1) is preferably in the form of particles with a volumetric particle diameter d95 of at most 100 µm, preferably of at most 40 µm, and particularly preferably of at most 10 µm. Particles with such particle diameters are also referred to as micronized particles. According to a further aspect of the invention, the composition has a proportion of 1 to 40 wt. % of the passivated, solid isocyanate (A), based on the total weight of the curable composition, preferably of 4 to 20 wt. %.Component (B): Isocyanate-reactive component In addition to the at least difunctional passivated and solid isocyanate (A), the curable composition according to the invention contains an isocyanate-reactive component (B). Hybrid compound (B1) According to the invention, component (B) comprises at least one liquid hybrid compound (B1) which, in addition to an isocyanate-reactive group, additionally contains at least one free-radically curable group and has a molar mass of at least 400 g / mol. The liquid hybrid compound (B1) preferably has a molar mass of at least 600 g / mol. The free-radically radiation-curable group is not structurally further restricted as long as it has an ethylenically unsaturated double bond. Suitable free-radically curable groups are, for example, (meth)acrylates, allyl ethers, vinyl ethers, isoprenes, and butadienes. The hybrid compound (B1) preferably contains at least one methacrylate group.In addition, the hybrid compound (B1) preferably contains at least one isocyanate-reactive group selected from the group of amino and hydroxyl groups, and combinations thereof. In addition to the number of organic radicals, the constitution of the radical bonded to the isocyanate-reactive group also influences the properties of the hybrid compound (B1). The hybrid compound (B1) preferably contains a primary amino group, a primary hydroxyl group, and / or a secondary hydroxyl group as an isocyanate-reactive group. The primary amine and / or the hydroxyl group of the hybrid compound (B1) are preferably bonded to a primary or secondary carbon atom. The hybrid compound (B1) particularly preferably contains at least one primary amino group as an isocyanate-reactive group and at least one (meth)acrylate group, in particular a methacrylate group, as a radically curable group.To ensure particularly good crosslinking of radically curing and addition-curing components with simultaneously high strengths, the hybrid compound (B1) preferably contains, in addition to a radically curable group and an isocyanate-reactive group, another of the groups mentioned. In other words, the average functionality of the hybrid compound (B1) is preferably at least three, based on the number of isocyanate-reactive and radically curable groups in the hybrid compound (B1). The hybrid compound (B1) preferably has a molecular weight of 400 to 20,000 g / mol, more preferably of 500 to 19,000 g / mol, and particularly preferably of 600 to 18,000 g / mol. If liquid hybrid compounds (B1) with a lower molecular weight, for example less than 400 g / mol, are used, incipient dissolution of the passivation layer of the passivated and solid isocyanate (A) may occur.Formulating curable compositions with sufficient processing times is then not possible. If liquid hybrid compounds (B1) with a very high molecular weight, for example, more than 20,000 g / mol, are used, their viscosity increases to such an extent that homogeneous compositions cannot be formulated. The hybrid compound (B1) can be selected from the group of amine-functional hybrid compounds (B1-1), hydroxy-functional hybrid compounds (B1-2), and combinations thereof. Amine-functional hybrid compound (B1-1) Amine-functional hybrid compounds (B1-1) can be obtained by a partial reaction starting from polyamines (b1-1-1) with an isocyanate-functional (meth)acrylate (b1-1-2). The reaction of the polyamine (b1-1-1) with an isocyanate-functional (meth)acrylate (b1-1-2) can optionally be carried out with the addition of a catalyst. Suitable catalysts are tertiary amine compounds such as triethylamine.The structure of the polyamines (b1-1-1) is not further restricted. Polyoxyalkyleneamines (polyether-based), polyethyleneimines (polyaziridines), polyamidoamines, or phenalkamines can be used. Polyamines (b1-1-1) based on polyoxyalkyleneamines with units of ethylene, propylene (1,2- and 1,3-propylene), tetramethylene, tetrahydropyran, or mixtures thereof are preferred. Commercially available polyoxyalkyleneamines are available, for example, under the name Jeffamine. ® THF-100, Jeffamine ® THF-170, Jeffamine ® D-205, Jeffamine ® D-230, Jeffamine ® D-400, Jeffamine ® D-2000, Jeffamine ® D-2010, Jeffamine ® D-4000, Jeffamine ® T-403, Jeffamine® T-3000, Jeffamine® T-5000, Jeffamine ® EDR-148, Jeffamine ® EDR-176, Jeffamine ® ED-600, Jeffamine ® ED-900 or Jeffamine ®ED-2003 der Firma Huntsman Corporation or as Typen Baxxodur ® EC 130, Baxxodur ® EC 280, Baxxodur ® EC 301, Exodus ® EC 302, Baxxodur ® EC 303, Baxxodur ® EC 310 oder Baxxodur ®EC 311 is available from BASF SE. An extension of the polyamines (b1-1-1) by a prior reaction with bismalimides, di- or higher-functional acrylates, or aliphatic and / or aromatic di- or higher-functional glycidyl ethers to form higher-molecular-weight polyoxyalkyleneamines is also within the scope of the invention. Isocyanate-functional (meth)acrylates (b1-1-2) Suitable isocyanate-functional (meth)acrylates (b1-1-2) are, for example, reaction products such as those obtained by a process described in DE 3025227 A1 by reacting aliphatic, cycloaliphatic, and / or aromatic, at least difunctional isocyanates (b1-1-3) with hydroxy-functional (meth)acrylates (b1-1-4). Preferably, the at least difunctional isocyanate (b1-1-3) is used in an excess of 20 wt.% or more, based on the hydroxy-functional (meth)acrylate (b1-1-4).Excess, unreacted monomeric, at least difunctional, isocyanates (b1-1-3) can be separated from the reaction mixture by distillation, for example, by distillation under vacuum using a thin-layer, thin-film, or short-path evaporator. Such distillation processes are described in Kunststoff Handbuch Volume 7, "Polyurethanes" (GW Becker (editor), Hanser-Verlag, Munich, 3rd edition 1993, page 425). Further commercial examples of isocyanate-functional (meth)acrylates (b1-1-2) are 2-isocyanatoethyl methacrylate (Karenz MOI), 2-isocyanatoethyl acrylate (Karenz AOI), 1,1-bis(acryloyloxymethyl)ethyl isocyanate (Karenz BEI), 2-(2-isocyanatoethoxy)ethyl methacrylate (Karenz MOI-EG), available from Resonac Corporation and 2-hydroxyethyl propenoate adduct with 5-isocyanato-1-(isocyanatomethyl)-1,3,3-trimethylcyclohexane (VESTANAT EP-DC 1241), available from Evonik.Examples of at least difunctional isocyanates (b1-1-3) for the preparation of isocyanato-functional (meth)acrylates (b1-1-2) include hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-diisocyanatodicyclohexylmethane, methylene diphenyl isocyanate, 2,4,4-trimethylhexane-1,6-diisocyanate, 2,2,4-trimethylhexane-1,6-diisocyanate, toluene-2,4-diisocyanate and toluene-2,6-diisocyanate, which are commercially available under the trade name Desmodur from Covestro AG or under the trade name Vestanat from Evonik Operations GmbH. Other suitable at least difunctional isocyanates (b1-1-3) are meta-tetramethylxylylene diisocyanate from Allnex Germany GmbH and m-xylylene diisocyanate and 1,3-bis(isocyanatomethyl)cyclohexane, which are commercially available under the trade name Takenate from Mitsui Chemicals Inc.Other suitable at least difunctional isocyanates (b1-1-3) are 4,4'-diisocyanato-3,3'-dimethylbiphenyl, available from Nisso Chemical Europe GmbH, as well as 1,5-naphthylene diisocyanate, 1,3-phenylene diisocyanate, and 1,4-phenylene diisocyanate, available from TCI Chemicals. Blends of the above-mentioned at least difunctional diisocyanates (b1-1-3) are also included. Examples of hydroxy-functional (meth)acrylates (b1-1-4) are 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, glycerol di(meth)acrylate, glycerol mono(meth)acrylate, trimethylolpropane di(meth)acrylate, pentaerythritol tri(meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, polyalkylene glycol mono(meth)acrylate, polycaprolactone (meth)acrylate, and dipentaerythritol penta(meth)acrylate. Blends of the raw materials mentioned are also included.These raw materials are commercially available from Evonik Operations GmbH, Arkema Sartomer, and GEO Specialty Chemicals. Optionally, one or more catalysts (b1-1-5) can be used to accelerate the reaction of the at least difunctional isocyanate (b1-1-3) and the hydroxyfunctional (meth)acrylate (b1-1-4). Suitable catalysts (b1-1-5) include organometallic compounds of tin, zinc, iron, titanium, or bismuth, such as dibutyl or dioctyltin diacetate, dibutyl or dioctyltin dilaurate, and tributyltin acetate. Other suitable catalysts (b1-1-5) are carboxylic acid salts of the above-mentioned elements, such as tin(II) acetate, tin(II) 2-ethylhexanoate, zinc(II) 2-ethylhexanoate, and bismuth(III) neodecanoate. Also suitable catalysts are amine compounds such as DABCO, DBU, triethylamine and other tertiary amines.During the synthesis of the isocyanate-functional (meth)acrylates (b1-1-2), the amine-functional hybrid compounds (B1-1), and the hydroxy-functional hybrid compounds (B1-2), suitable stabilizers such as phenolic antioxidants or other radical scavengers and / or stabilizers known to those skilled in the art can optionally be added. Another possible preparation of the amine-functional hybrid compound (B1-1) involves a partial reaction of polyamines (b1-1-1) with (meth)acrylic anhydride. The (meth)acrylic acid present as a byproduct can either remain in the system or be removed. This can be achieved, for example, by distillation under vacuum using a thin-layer, thin-film, or short-path evaporator. Removal by washing out the byproduct is also possible.Hydroxy-functional hybrid compound (B1-2) Higher-molecular-weight hydroxy-functional hybrid compounds (B1-2) that can be used include, for example, compounds based on polyethers, polyesters, polycarbonates, unhydrogenated or partially to fully hydrogenated polybutadienes, and unhydrogenated or partially to fully hydrogenated polyisoprenes. Hydroxy-functional hybrid compounds (B1-2) can also be obtained by partial reaction of hydroxy-functional polyols (b1-2-1) with isocyanato-functional (meth)acrylates (b1-1-2), as previously described for the amine-functional hybrid compound (B1-1). Hydroxy-functional polyol (b1-2-1) The structure of the possible hydroxy-functional polyols (b1-2-1) is not further restricted. For example, polyether polyols or polyalkylene glycols with units of ethylene, propylene (1,2- and 1,3-propylene), tetramethylene, tetrahydropyran or mixtures thereof can be used.These are commercially available, for example, as Acclaim, Desmophen, Baycoll, Caradol, Lupranol, Voranol, Rokopol, Velvetol, Ecotrion, PolyTHF, PTG, PTMG, or PTMEG grades. Furthermore, the polyols (b1-2-1) include polyester polyols with aliphatic and / or aromatic units, which are commercially available, for example, under the names Kuraray, CAPA, Desmophen, Baycoll, Priplast, or Placcel grades. Also included are polyols (b1-2-1) based on polycarbonates, available as Kuraray, Eternacoll, or Placcel grades. Other suitable polyols (b1-2-1) are based on polybutadienes and hydrogenated polybutadienes, available as Krasol. ® -, Polyvest ® -, Nisso-PB ®-, Poly bd or EPOL types as well as polyisoprenes as Poly ip types. The polyol types mentioned are available from companies such as Evonik Operations GmbH, Covestro AG, Shell Chemicals, BASF SE, DOW, PCC Rokita SA, Mitsubishi Chemical Group, Hodogaya Chemical, Kuraray Europe GmbH, Perstorp Holding, Ingevity, Cargill, Daicel ChemTech Inc., UBE Corporation, WeylChem International GmbH, Gantrade Corporation, Dairen Chemical Corporation (DCC), Cray Valley, Idemitsu Kosan Co. Ltd. and Nippon Soda Co. Ltd. The reaction of the hydroxy-functional polyol (b1-2-1) with an isocyanate-functional (meth)acrylate (b1-1-2) to form the hydroxy-functional hybrid (B1-2) can be carried out analogously to the reaction of hydroxy function with isocyanate function described above, optionally with the addition of a catalyst (b1-1-5). Another possible preparation of component (B1-2) involves a partial reaction of hydroxy-functional polyols (b1-2-1) with (meth)acrylic anhydride.The (meth)acrylic acid present as a by-product can either remain in the system or be removed. This can be achieved, for example, by distillation under vacuum using a thin-layer, thin-film, or short-path evaporator. Removal by washing the by-product is also possible. To accelerate the reaction of hydroxy-functional polyols (b1-2-1) with (meth)acrylic anhydride, one or more catalysts (b1-2-2) such as pyridine, triethylamine, 4-(dimethylamino)pyridine, sulfuric acid, p-toluenesulfonic acid, or alkali metal hydroxides can be used. The hybrid compound (B1) is preferably present in the composition according to the invention in a proportion of 20 to 100 wt. %, more preferably in a proportion of 30 to 80 wt. %, based on the total weight of component (B).Second liquid isocyanate-reactive component (B2) Optionally, the isocyanate-reactive component (B) comprises, in addition to the hybrid compound (B1), a second liquid isocyanate-reactive component (B2). This component contains one or more isocyanate-reactive groups and no other radically curable groups. In principle, the selection of component (B2) from the group of alcohols, amines, and thiols, as well as mixtures thereof, is not restricted as long as it is liquid at room temperature. Component (B2) is not further restricted with regard to its chemical constitution. The average functionality of the second, isocyanate-reactive component (B2) is preferably at least two, based on the isocyanate-reactive groups of component (B2). The cured masses can be specifically formed with hard and soft segments.To form hard segments, preferably liquid isocyanate-reactive components (B2) with a molecular weight of up to about 400 g / mol are used as so-called chain extenders, which form a high density of linking groups such as (thio)urethane or urea groups with the at least difunctional passivated and solid isocyanate (A1) in the heat-curing step, which then link together via a dense network of hydrogen bonds. To form soft segments, component (B2) preferably comprises long-chain isocyanate-reactive compounds with a molecular weight of 400 g / mol to 20,000 g / mol. The isocyanate-reactive compounds can also be pre-extended with liquid, non-passivated isocyanates to form prepolymers. Component (B2) preferably comprises an amine. Polyetheramines with a molecular weight of 600 g / mol or higher, such as those sold as Jeffamine, can be used as the amine in component (B2). ®D-2000 or Jeffamine ® T-5000. Higher molecular weight aromatic amines with an average molecular weight of 400 g / mol to 12,000 g / mol are also preferred, which can be obtained according to EP 0071834 A1 by alkaline hydrolysis of compounds with terminal isocyanate groups, in particular from isocyanate prepolymers. Suitable aromatic diamines are available under the name Versalink. ® P-650 and Versalink ® P-1000 is commercially available. Aromatic diamines such as diethylenetoluenediamine, available as Ethacure 100, can also be used as chain extenders. Furthermore, a polyol can be used as component (B2), particularly preferably a long-chain polyol with an average molecular weight M n from 400 g / mol to 20,000 g / mol. Examples of suitable long-chain polyols are polyether-based polyols, commercially available as Acclaim ®-Types, polyesters and polycarbonates, available as Kuraray ® - or Priplast TM -Types, as well as polyols based on polybutadienes and hydrogenated polybutadienes, available as Krasol ® -, Polyvest ® - or Nisso-PB ®- Types. Long-chain polyols with an average molecular weight of 2,000 g / mol to 20,000 g / mol are particularly suitable for the production of curable materials that, after curing, exhibit high flexibility at low temperatures and a low glass transition temperature. Component (B2) can comprise at least one low-molecular-weight polyol with a molecular weight of up to 400 g / mol as a chain extender, such as glycol, glycerol, 1,4-butanediol, or 2-ethyl-1,3-hexanediol. Suitable thiols for use in component (B2) include, for example, ester-based thiols such as trimethylolpropane tris-(3-mercaptopropionate) or pentaerythritol tetrakis-(3-mercaptobutylate). Furthermore, polyethers terminated with thiol groups can be used as isocyanate-reactive components, as can polythioethers bearing thiol groups or tris-(3-mercaptopropyl)-isocyanurate.The second liquid, isocyanate-reactive component (B2) is preferably present in the composition according to the invention in a proportion of 0 to 50 wt. %, more preferably in a proportion of 0 to 30 wt. %, based in each case on the total weight of component (B). Solid isocyanate-reactive component (B3) In addition to the liquid hybrid compound (B1) and optionally (B2), the compositions optionally contain a solid isocyanate-reactive component (B3) having a melting point of at least 50°C. The solid isocyanate-reactive component (B3) can be selected from the group of alcohols, amines, and thiols, and mixtures thereof. Component (B3) is preferably selected from the group of alcohols and amines. In principle, any solid isocyanate-reactive compound having a melting point of 50°C or more, preferably 60°C or more, in particular 65°C or more, and more preferably not higher than 200°C, can be used as component (B3).The solid isocyanate-reactive component (B3) is present in the curable composition, in particular, in dispersed form and is not dissolved in the other constituents of component (B). The amine of the solid isocyanate-reactive component (B3) may be difunctional or more functional and may contain any desired additional isocyanate-reactive groups. In the case of a mixed-functional amine, a thiol or hydroxyl function is preferably present in addition to the amine function. Amine and hydroxyl functions are particularly preferably present in combination. Examples of this include epoxy-amine adducts, which, in addition to an amine function, have at least one further hydroxyl group. Preference is given to using compounds with a molecular weight of less than 5000 g / mol, more preferably less than 2000 g / mol, and particularly preferably less than 1000 g / mol as the solid, second isocyanate-reactive component (B3).Examples of the solid isocyanate-reactive component (B3) are 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4′-diaminodiphenylmethane, 4,4′-diamino-3,3′-dichlorodiphenylmethane, 4,4′-oxydianiline, bis(4-amino-3,5-diethylphenyl)methane, pentaerythritol, trimethylolpropane, or trimethylolethane. Suitable commercially available products include, for example, Aradur 9664-1 and Aradur 9719-1 from Huntsman and Charmor PM15 from Perstorp. Commercial epoxy-amine adducts are available, for example, under the names EH-5011S, EH-5046S, EH-5015SS, and EH-5057P from ADEKA, Ancamine 2014FG or Ancamine 2442 from Evonik, or Fujicure FXR-1020, Fujicure FXR-1030, Fujicure FXR-1081, or Fujicure FXR-1121 from Sanho Chemical. Based on the weight of component (B), the proportion of the solid isocyanate-reactive component (B3) is preferably in a range from 0 to 40 wt. %, more preferably in a range from 1 to 25 wt. %.The isocyanate-reactive component (B) is preferably present in the composition of the invention in a proportion of 5 to 90 wt. %, more preferably in a proportion of 10 to 70 wt. %, based in each case on the total weight of the composition. Component (C): Initiator system for radical polymerization. In addition to the at least difunctional solid and passivated isocyanate (A) and the isocyanate-reactive component (B), comprising at least the hybrid compound (B1), the curable compositions of the invention contain an initiator system (C) for radical polymerization, comprising a first initiator (C1) and a second initiator (C2), where the first initiator (C1) is a radical photoinitiator (C1) and the second initiator (C2) is a radical initiator for heat curing. The initiator system (C) preferably consists of the first initiator (C1) and the second initiator (C2).First initiator (C1) The first initiator (C1) acts as a radical photoinitiator, enabling the light fixation of the curable mass and thus crosslinking of the radically curable groups of the hybrid compound (B1), as well as other, optionally added, radically curing formulation components.All customary, commercially available compounds can be used as radical photoinitiator (C1), such as, for example, α-hydroxy ketones, benzophenone, α,α'-diethoxyacetophenone, 4,4-diethylaminobenzophenone, 2,2-dimethoxy-2-phenylacetophenone, 4-isopropylphenyl 2-hydroxy-2-propyl ketone, 1-hydroxycyclohexylphenyl ketone, isoamyl p-dimethylaminobenzoate, methyl 4-dimethylaminobenzoate, methyl o-benzoylbenzoate, benzoin, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-isopropylthioxanthone, dibenzosuberone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bisacylphosphine oxides, wherein the compounds mentioned alone or in combination with two or more of the compounds mentioned can be used as a radical photoinitiator (C1). IRGACURE can be used as a radical photoinitiator (C1) that can be activated by UV radiation. TM-grades from BASF SE are used, such as the grades IRGACURE 184, IRGACURE 500, IRGACURE 1179, IRGACURE 2959, IRGACURE 745, IRGACURE 651, IRGACURE 369, IRGACURE 907, IRGACURE 1300, IRGACURE 819, IRGACURE 819DW, IRGACURE 2022, IRGACURE 2100, IRGACURE 784, IRGACURE 250, IRGACURE TPO, IRGACURE TPO-L. Furthermore, the DAROCUR TM-Types from BASF SE can be used, for example the types DAROCUR MBF, DAROCUR 1173, DAROCUR TPO and DAROCUR 4265. The above lists are to be regarded as examples of the free-radical photoinitiator (C1) and are in no way to be understood as limiting. The free-radical photoinitiator used as component (C1) in the compositions according to the invention can preferably be activated by actinic radiation having a wavelength of 200 to 400 nm, particularly preferably 250 to 365 nm. If required, the free-radical photoinitiator (C1) can be combined with a suitable sensitizer. The free-radical photoinitiator (C1) is present in the compositions in particular in a proportion of 0.01 to 5% by weight, preferably 0.5 to 3% by weight, based in each case on the total weight of the composition. Second initiator (C2) The second initiator (C2), i.e. the radical initiator for heat curing, can be selected, for example, from peroxo compounds and / or benzpinacols.Suitable peroxo compounds include, for example, peroxo(di)esters, hydroperoxides, (di)alkyl peroxides, ketone peroxides, perketals, peracids, and peroxomonocarbonates. Furthermore, peroxodicarbonates, as described, for example, in WO 2023030763 A1, can be advantageously used in the composition according to the invention. Examples of suitable peroxoesters include cumene peroxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, tert-amylperoxyneodecanoate, tert-butylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxypivalate, tert-amylperoxypivalate, tert-butylperoxypivalate, Didecanoyl peroxide, dilauroyl peroxide, 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)-hexane, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, tert-amyl peroxy-2-ethylhexanoate, dibenzoyl peroxide, tert-butyl peroxy-2-ethylhexanoate, tert-Butylperoxyisobutyrate, tert-Butylperoxy-3,5,5-trimethylhexanoate, tert-butyl peroxyacetate and tert-butyl peroxybenzoate.Examples of suitable hydroperoxides include diisopropylbenzene monohydroperoxide, p-menthane hydroperoxide, cumene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, tert-butyl hydroperoxide, and tert-amyl hydroperoxide. Examples of suitable peroxomonocarbonates include tert-amyl peroxy-2-ethylhexyl carbonate, tert-butyl peroxyisopropyl carbonate, and tert-butyl peroxy-2-ethylhexyl carbonate. Examples of suitable peroxodicarbonates include di-(4-tert-butylcyclohexyl) peroxodicarbonate, di-(2-ethylhexyl) peroxodicarbonate, di-n-butyl peroxodicarbonate, dicetyl peroxodicarbonate, and dimyristil peroxodicarbonate. Benzpinacol and derivatives thereof, as described, for example, in US Pat. No. 4,288,527 A, can also be used as a radical initiator for heat curing (C2). These include, in particular, halogenated, alkylated, and methoxy-substituted benzpinacols. Protected benzpinacols can also be used as component (C2).These can be either mono- or di-protected and include silyl-protected, in particular mono- and di-trialkylsilyl-protected, benzpinacols. Examples of benzpinacols which can be used in the curable compositions according to the invention are 1,1,2,2-tetraphenyl-1,2-ethanediol, 1,1,2,2-tetrakis(4-methylphenyl)-1,2-ethanediol, 1,1,2,2-tetrakis(4-methoxyphenyl)-1,2-ethanediol, 1,1,2,2-tetrakis(4-chlorophenyl)-1,2-ethanediol, 1-hydroxy-2-trimethylsiloxy-1,1,2,2-tetraphenylethane, 1,1,2,2-tetraphenyl-1,2-bis-(trimethylsiloxy)-ethane and 1,1,2,2-tetrakis(4-methylphenyl)-1,2-bis-(trimethylsiloxy)-ethane. The radical initiator for the heat curing (C2) is present in the compositions according to the invention in a proportion of 0.01 to 10 wt.%, preferably 0.1 to 5 wt.%, in each case based on the total weight of the composition.Component (D): Further radically curable component The curable composition according to the invention optionally comprises a further radically curable component (D) containing at least one radically radiation-curable compound. The further radically radiation-curable component (D) serves in particular to ensure high light-fixation strength. The further radically curable component (D) can be reacted using both the radical photoinitiator (C1) and the radical initiator for heat curing (C2) and incorporated into the polymer network. The further radically curable compound (D) is not structurally restricted as long as it contains an ethylenically unsaturated double bond. Suitable examples include (meth)acrylates, allyl ethers, vinyl ethers, isoprenes, and butadienes.The further radically radiation-curable compound (D) is preferably at least difunctional with respect to the ethylenically unsaturated double bond. Component (D) preferably comprises radically curable compounds based on (meth)acrylates. For example, both aliphatic and aromatic (meth)acrylates can be used. Here and below, (meth)acrylates refer to both the derivatives of acrylic acid and methacrylic acid, as well as combinations and mixtures thereof.The following radiation-curable compounds are suitable, for example: isobornyl acrylate, stearyl acrylate, tetrahydrofurfuryl acrylate, cyclohexyl acrylate, 3,3,5-trimethylcyclohexanol acrylate, behenyl acrylate, 2-methoxyethyl acrylate and other mono- or polyalkoxylated alkyl acrylates, isobutyl acrylate, isooctyl acrylate, lauryl acrylate, tridecyl acrylate, isostearyl acrylate, 2-(o-phenylphenoxy)ethyl acrylate, acryloylmorpholine, N,N-dimethylacrylamide, 4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,10-decanediol diacrylate, tricyclodecanedimethanol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, polybutadiene diacrylate, cyclohexanedimethanol diacrylate, diurethane acrylates of monomeric, oligomeric or polymeric Diols and polyols, trimethylolpropane triacrylate (TMPTA), and dipentaerythritol hexaacrylate (DPHA), and combinations thereof.Higher-functionality acrylates derived from multiply branched or dendrimeric alcohols can also be used advantageously. The analogous methacrylates are also within the meaning of the invention. Also suitable are radiation-curable compounds containing allyl groups, such as, for example, 1,3,5-triallyl-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, which is commercially available as TAICROS®. Compounds containing allyl groups lead to rapid fixing processes, particularly in the presence of thiols. Unhydrogenated polybutadienes with free double bonds, such as the Poly BD® types, can also be used as radiation-curing compounds. Urethane acrylates based on polyesters, polyethers, polycarbonatediols and / or (hydrogenated) polybutadienediols can be used as higher-molecular-weight radiation-curable compounds in the second curable component (B). A combination of several radiation-curable compounds is also within the meaning of the invention.The radically curable component (D) is present in the composition of the invention in particular in a proportion of 0 to 50 wt. %, preferably in a proportion of 5 to 30 wt. %, based in each case on the total weight of the curable composition. Component (E): Additives In addition to components (A) to (D), the curable compositions of the invention may contain further additives (E). Examples which may be used as additives (E) include catalysts, toughness modifiers such as core-shell particles or block copolymers, anti-aging agents, dyes, fluorescent agents, pigments, thixotropic agents, thickeners, thermal stabilizers, stabilizers, antioxidants, plasticizers, fillers, flame retardants, thermally and / or electrically conductive particles, corrosion inhibitors, water scavengers, diluents, flow control and wetting additives, adhesion promoters, and combinations thereof.In principle, inert organic solvents can also be used as diluents, as long as they do not dissolve the passivated and solid polyisocyanate (A). However, the curable composition is preferably free of inert organic solvents, since the use of such solvents is disadvantageous from an environmental point of view and is therefore not preferred. In principle, water can also be used as a dispersing medium. However, this necessitates a complex drying step in the processing of the curable composition, which means that the use of an aqueous dispersion is also not preferred. Pyrogenic silicas, which have optionally been surface-modified, are preferably used as thixotropic agents. The additives (E) are preferably present in the curable composition in a proportion of 0 to 80 wt. %, particularly preferably in a proportion of 0 to 50 wt. %, based on the total weight of the composition.Composition of the curable compositions according to the invention. The curable composition according to the invention preferably comprises or consists of the aforementioned components (A) to (E). Advantageously, the curable composition contains at least one additive (E).According to a first preferred embodiment, the curable composition according to the invention comprises the following components: (A) an at least difunctional passivated and solid isocyanate; (B) an isocyanate-reactive component comprising at least one hybrid compound (B1) which, in addition to at least one isocyanate-reactive group, contains at least one radically curable group, wherein the hybrid compound (B1) has a molecular weight of at least 400 g / mol; and (C) an initiator system for the radical polymerization (C) comprising a first initiator (C1) and a second initiator (C2), wherein the first initiator (C1) is a radical photoinitiator (C1) and the second initiator (C2) is a radical initiator for heat curing (C2).In a second preferred embodiment, the composition according to the invention comprises the following components: (A) an at least difunctional, passivated and solid isocyanate; (B) an isocyanate-reactive component comprising at least one hybrid compound (B1) which, in addition to at least one isocyanate-reactive group, contains at least one radically curable group, wherein the hybrid compound (B1) has a molecular weight of at least 400 g / mol; (C) an initiator system for the radical polymerization (C) comprising a first initiator (C1) and a second initiator (C2), wherein the first initiator (C1) is a radical photoinitiator (C1) and the second initiator (C2) is a radical initiator for heat curing (C2); and (D) at least one further radically curable component (D). By adding the further radically curable component (D), the light-fixing strength of the composition can be adjusted and advantageously increased.The second initiator (C2) as a radical initiator for heat curing ensures complete curing of the further radically curable component (D) in shadow zones in the final heat curing step.In a third preferred embodiment, the curable composition according to the invention comprises the following components: (A) an at least difunctional passivated and solid isocyanate; (B) an isocyanate-reactive component comprising at least one hybrid compound (B1) which, in addition to at least one isocyanate-reactive group, contains at least one radically curable group, wherein the hybrid compound (B1) has a molecular weight of at least 400 g / mol, and at least one second liquid, isocyanate-reactive component (B2); and (C) an initiator system for the radical polymerization (C) comprising a first initiator (C1) and a second initiator (C2), wherein the first initiator (C1) is a radical photoinitiator (C1) and the second photoinitiator (C2) is a radical initiator for heat curing.By adding a second, liquid isocyanate-reactive component (B2), and optionally one or more chain extenders, the mechanical properties of the curable composition, such as the Young's modulus and glass transition temperature, can be adjusted over a wide range. Furthermore, the crosslinking density can be adjusted almost arbitrarily by combining difunctional and higher-functional isocyanate-reactive compounds (B2), as long as a polymeric network forms upon application of heat through the addition reaction to the at least difunctional isocyanate (A).In a fourth preferred embodiment, the composition according to the invention comprises the following components: (A) an at least difunctional passivated and solid isocyanate; (B) an isocyanate-reactive component comprising at least one hybrid compound (B1) which, in addition to at least one isocyanate-reactive group, contains at least one radically curable group, wherein the hybrid compound (B1) has a molecular weight of at least 400 g / mol, and at least one solid isocyanate-reactive component (B3); and (C) an initiator system for the radical polymerization (C) comprising a first initiator (C1) and a second initiator (C2), wherein the first initiator (C1) is a radical photoinitiator (C1) and the second photoinitiator (C2) is a radical initiator for heat curing.By adding a solid isocyanate-reactive component (B3) with a melting point of 50°C or higher, cured compositions with particularly good temperature resistance can be obtained. In addition, adhesion, particularly to metal surfaces, can be increased. Properties of the compositions according to the invention The compositions according to the invention are liquid at room temperature and can be formulated as a single-component composition. The curable composition is preferably a one-component composition. Due to the passivation of the at least difunctional and solid isocyanate (A1), the compositions can be processed at room temperature, at least for a certain period of time. The compositions can be processed without restriction as long as the increase in viscosity after storage is less than 25%, based on the viscosity at the beginning of storage. The curable compositions according to the invention meet this criterion even after 72 hours of storage at room temperature.The compositions according to the invention can also be fixed within a few seconds by irradiation with actinic radiation, so that the shape and position of the adhesive, i.e., the fixed composition, and the joining partners can be precisely adjusted in a single joining process. Light fixation strengths of preferably at least 0.3 MPa (glass / aluminum) are achieved. By appropriately selecting the hybrid component (B1) and the optional additional radically curable component (D), the speed of light fixation and the resulting light fixation strength can be advantageously influenced. The curable compositions according to the invention thus allow a temporal and spatial separation of an oven process for heat curing from further production steps. This enables higher throughput in industrial production processes.The use of a radical initiator for heat curing as the second initiator (C2) ensures complete crosslinking of the radically curable groups and components, particularly in shadow zones, resulting in homogeneous properties of the cured mass throughout its entire volume. The hybrid compound (B1) also enables reliable linking of the networks of light and shadow areas, enabling high final strengths to be achieved. The compressive shear strengths (Alu / Alu) of the cured masses are preferably at least 1 MPa, preferably at least 2.5 MPa. The cured masses also possess a consistently low elastic modulus over a wide temperature range and offer high heat and media resistance. In particular, the cured mass has an elastic modulus in the range from 5 MPa to 500 MPa, which is largely constant over a temperature range from -35 °C to 100 °C.This is also due to the fact that the glass transition temperature of the cured composition is usually -40 °C or lower. The possible volume reduction (shrinkage) of the light network also counteracts volume expansion during isocyanate curing, making the curable compositions suitable for bonding optical modules, particularly in the camera sector. The volume change during fixing and curing of the composition can, for example, range from -10% to +20%, based on the initial volume of the composition after dispensing. Curable compositions with a volume reduction during the curing process are also suitable for formulating thermally and / or electrically conductive systems. Processing methods using the compositions according to the invention The curable compositions according to the invention are characterized in particular by the fact that they can be fixed by light and subsequently cured at low temperatures.The heat-curing step can be carried out temporally and spatially decoupled. A corresponding method for joining, casting, or coating substrates using the curable compositions according to the invention comprises the following steps: (a) metering the curable composition onto a first substrate; (b) optionally supplying a second substrate to form a substrate composite; (c) fixing the curable composition with actinic radiation; (d) heat-curing the fixed composition on the substrate and / or in the substrate composite by heating to a temperature of at least 60°C. The curable compositions are particularly suitable for applications in which the strength build-up is to be specifically controlled by light fixation and, at the same time, reliable curing in shadow zones is to be ensured, especially in the case of non-transmissible substrates.This property profile is particularly required in the production of electro-optical components such as camera modules, the joining of displays, or encapsulations with complex geometries, for example sensor encapsulations. The alignment of components, for example in an active alignment process, can lead to inhomogeneous adhesive thicknesses between the joining partners. This results in shrinkage or volume expansion during the curing process having different effects, leading to local stress introduction into the components. An adhesive with low shrinkage or preferably zero shrinkage, i.e. essentially constant volume during the bonding process, counteracts this problem. Heat curing preferably takes place at a temperature at which the at least difunctional passivated and solid isocyanate (A) is dissolved or melted, breaking up the passivating shell, in particular the polyurea shell.Hot curing is preferably carried out at a temperature of at least 50°C, more preferably at least 60°C, but not higher than 200°C, preferably not higher than 180°C. The mass can be heated for curing, for example, in a convection oven, using a thermode, an IR radiator, a laser, by means of microwaves or by induction. Depending on the heat source and temperature, curing can take place within a few seconds up to a maximum of 2 hours. With the aid of the process using the curable masses according to the invention, a high degree of positional accuracy of the joined components can be achieved right up to final curing. Conventional fixing aids, which cannot be used in practice for miniaturized components or represent an unreasonable additional expense, can thus be dispensed with. Measurement methods and definitions used Room temperature Room temperature is defined as 23°C ± 2°C.Particle size distribution The particle size distribution was determined using a Microtrac S3500 particle size analyzer by laser light diffraction in accordance with ISO 13320. The distribution indicated by the value d95 refers to the volumetric particle diameter. Light fixation strength The light fixation strengths were determined using a "die shear" tester from Dage Semiconductor GmbH, type DAGE BT SERIES4000PX. The test instructions are based on the MIL-STD-883 standard, method 2019.5. In each case, a glass cube (dimensions 4 mm * 4 mm * 4 mm) was bonded to a second test specimen (dimensions 20 mm * 20 mm * 5 mm) made of clad aluminum. For this purpose, a drop of the curable compound was applied to the aluminum test specimen, and the glass cube was joined. The adhesive layer thickness of 0.1 mm and the overlap were adjusted using spacer wires and a bonding device.The bonded specimens were irradiated at a wavelength of 400 nm for 10 s using a DELOLUX 20 / 400 LED lamp at an intensity of 200 mW / cm². Compressive shear strength: Two specimens (dimensions 20 mm x 20 mm x 5 mm) made of clad aluminum were bonded together with a 5 mm overlap using the respective compound. For this purpose, a bead of the compound was applied to the first specimen. A second specimen was then bonded. The adhesive layer thickness of 0.1 mm and the overlap were adjusted using spacer wires and a bonding device. Heat curing took place in a preheated convection oven at 120 °C for 60 minutes. The specimens were conditioned at room temperature for 24 hours before testing. Glass transition temperature and storage modulus The dynamic mechanical properties of the cured masses were determined by dynamic mechanical thermal analysis (DMTA) in accordance with ISO 6721.The test specimens measuring 15 x 5 x 0.5 mm³ were cured for 60 minutes at 120 °C in a suitable plastic mold. The glass transition temperature is defined as the value at which the first derivative of the storage modulus (E') is minimal (inflection point, see ISO 6721-11:2012, Section 3.1). The storage modulus for the respective temperatures was determined according to ISO 6721-4:2008. The measurement was carried out in a temperature range from 0 to 300 °C with a heating rate of 3 K / min at a frequency of 1 Hz with an amplitude of 30 µm. A "DMA 242E" from Netzsch was used as the measuring device. GPC measurement The average molar masses M. n were determined using a Viscotek TDA 302 GPC (refractive index and viscosity detector), available from Malvern Panalytical GmbH. The GPC columns used were Viscotek LT4000L (mixed bed) and Viscotek T1000 (single-pore) and were calibrated with polystyrene calibration standards from M nCalibrated from 162 Da to 51,150 Da. Tetrahydrofuran was used as the mobile phase. The flow rate was 1 mL / min at a measurement temperature of 35 °C. To improve the measurability of amines using liquid chromatography and the described column combination, the amine functions were saturated with an excess of derivatization reagent such as hexahydro-4-methylphthalic anhydride during sample preparation. Alternative techniques for derivatizing amines are known to those skilled in the art. For sample preparation, 40 mg of the sample were dissolved in 10 ml of THF, and 15 µl of derivatization reagent were added. After a residence time of 15 min, the solution was filtered through a syringe filter (0.2 µm), and 100 µl of the solution was injected via an injection loop. Viscosity The viscosity was measured using a Physica MCR302 rheometer from Anton Paar with a standardized PP20 measuring cone at 23 °C with a 200 μm gap and determined at a shear rate of 10 / second.To assess processability at room temperature, the viscosity measurement was repeated after 72 hours. The compositions according to the invention can be processed for a period of at least 72 hours. This criterion is met if, when stored at room temperature, the increase in viscosity over a period of 72 hours is less than 25%. Volume change / shrinkage The volume measurements were carried out using a Pycnomatic ATC helium pycnometer from Porotec Pycnomatic in accordance with IN 66137-2 (determination of the density of solids). Both the density of the curable composition and the density of the cured composition were determined. To measure the density of the cured adhesive, 28 cylindrical test specimens (1 mm thick, 22 mm diameter) were produced using a suitable mold. These were then irradiated at a wavelength of 400 nm for 60 s using a DELOLUX 20 / 400 LED lamp with an intensity of 200 mW / cm².Subsequent hot curing took place in a preheated convection oven at 120 °C for 60 minutes. The test specimens were conditioned at room temperature for 24 hours prior to testing. Since no measurable mass loss occurred during curing, the volume change was calculated as follows: S = 1 - ρL / ρS. Volume shrinkage: S Density of the liquid adhesive: ρL Density of the cured adhesive: ρS Production examples To produce the curable compositions according to the invention, the hybrid compound (B1) and optionally the second liquid isocyanate-reactive component (B2) were first mixed with the passivating agent (A2), and the micronized, solid isocyanate (A1) was added. The other components were then added and blended according to the contents specified in the tables in weight percent. Mixing took place in a Labotop with sickle-shaped kneading arms (PC Laborsysteme). The compositions were then degassed and filled into cartridges.Curing of the curable compositions according to the invention and of the comparison compositions is initiated by the passivated and solid isocyanate (A) being dissolved or melted at elevated temperature with rupture of the passivating shell. Curing of the curable compositions according to the invention and comparative examples was carried out by heating to 120 °C for 60 minutes. Depending on the type and amount of passivating agent (A2) used for passivating the polyisocyanate (A1), an adjustment of the curing temperature may be necessary. The energy input for hot curing can be via convection, for example in a circulating air oven, by heat conduction, for example by means of a hot plate or thermode, or by means of electromagnetic radiation, for example by means of IR radiation sources, lasers, microwaves or induction.Synthesis Examples Synthesis Example 1: Amine-Functional Hybrid Compound (B1-1-1) 503.30 g of the polyoxyalkylene amine Jeffamine T-5000 (Huntsman Corporation) (b1-1-1) were placed in a suitable reaction vessel. 0.27 g of hydroquinone monomethyl ether (Sigma Aldrich) and 0.27 g of 2,6-di-tert-butyl-4-methylphenol (Sigma Aldrich) were added and dissolved. With constant stirring, 27.18 g of 2-isocyanatoethyl methacrylate Karenz MOI (Resonac Corporation) (b1-1-2) were gradually added, and then the temperature was raised to 40 °C. The reaction was maintained at this temperature for a further 30 minutes, and the disappearance of the NCO absorption in the infrared absorption spectrum was monitored. After completion of the reaction, the reaction was stopped. The product was an amine-functional hybrid compound (B1-1) with an average of one amino group and two methacrylate groups and with an average molecular weight M. nof 8,150 g / mol was obtained. Synthesis Example 2: Amine-Functional Hybrid Compound (B1-1-2) 453.70 g of the polyoxyalkyleneamine Jeffamine T-3000 (Huntsman Corporation) (b1-1-1) were placed in a suitable reaction vessel. 0.26 g of hydroquinone monomethyl ether (Sigma Aldrich) and 0.26 g of 2,6-di-tert-butyl-4-methylphenol (Sigma Aldrich) were added and dissolved. With constant stirring, 45.23 g of 2-isocyanatoethyl methacrylate Karenz MOI (Resonac Corporation) (b1-1-2) were gradually added, and then the temperature was raised to 40 °C. The reaction was maintained at this temperature for a further 30 minutes, and the disappearance of the NCO absorption in the infrared absorption spectrum was monitored. After completion of the reaction, the reaction was stopped. The product was an amine-functional hybrid compound (B1-1-2) with an average of one amino group and two methacrylate groups and with an average molecular weight M nof 4.947 g / mol was obtained. Synthesis Example 3: Amine-Functional Hybrid Compound (B1-1-3) 405.30 g of the polyoxyalkyleneamine Jeffamine THF-100 (Huntsman Corporation) (b1-1-1) were placed in a suitable reaction vessel. 0.24 g of hydroquinone monomethyl ether (Sigma Aldrich) and 0.24 g of 2,6-di-tert-butyl-4-methylphenol (Sigma Aldrich) were added and dissolved. With constant stirring, 62.20 g of 2-isocyanatoethyl methacrylate Karenz MOI (Resonac Corporation) (b1-1-2) was gradually added, and then the temperature was raised to 40 °C. The reaction was maintained at this temperature for a further 30 minutes, and the disappearance of the NCO absorption in the infrared absorption spectrum was monitored. After completion of the reaction, the reaction was stopped. The product was an amine-functional hybrid compound (B1-1-3) with an average of one amino group and one methacrylate group and with an average molecular weight M nof 2.074 g / mol was obtained. Synthesis Example 4: Hydroxy-Functional Hybrid Compound (B1-2-1) 611.22 g of the hydrogenated hydroxy-functional polybutadiene Krasol HLBH-P 3000 (Cray Valley) (b1-2-1) were placed in a suitable reaction vessel. 0.25 g of hydroquinone monomethyl ether (Sigma Aldrich) and 0.25 g of 2,6-di-tert-butyl-4-methylphenol (Sigma Aldrich) were added and dissolved. With constant stirring, 29.04 g of 2-isocyanatoethyl methacrylate Karenz MOI (Resonac Corporation) (b1-1-2) was gradually added. 0.12 g of dibutyltin dilaurate (Sigma Aldrich) was added as a catalyst, and the temperature was increased to 60 °C. The reaction was maintained at this temperature for a further 3 hours, and the disappearance of the NCO absorption in the infrared absorption spectrum was monitored. After completion, the reaction was stopped.The product was a hydroxy-functional hybrid compound (B1-2-1) with an average of one hydroxy group and one methacrylate group with an average molecular weight M. nof 5,489 g / mol. Examples of applications: The following list contains all compounds used to prepare the curable materials and their abbreviations. Component (A): at least difunctional passivated and solid isocyanate A1-1 – Thanecure T9 SF AD-V – micronized TDI uretdione (TSE Industries) A1-2 – Desmodur Z2589 – micronized IPDI trimer (Covestro AG) A2-1 – Jeffamine D-400 – liquid polyetheramine (Huntsman Corporation) Component (B): isocyanate-reactive component B1-1-1 – amine-functional hybrid compound according to Synthesis Example 1 B1-1-2 – amine-functional hybrid compound according to Synthesis Example 2 B1-1-3 – amine-functional hybrid compound according to Synthesis Example 3 B1-2-1 – hydroxy-functional hybrid compound according to Synthesis Example 4 B1-2-2 – VISIOMER HEMA - 2-hydroxyethyl methacrylate (Evonik Industries) B2-1 – Jeffamine T-5000 – liquid polyetheramine (Huntsman Corporation) B2-2 – Ethacure 100 Plus – Diethyltoluenediamine (liquid) asChain extender (Albemarle Corporation) B2-3 – Krasol HLBH-P 3000 – liquid polybutadiene-based polyol (Cray Valley) B2-4 – Jeffamine T-3000 – liquid polyetheramine (Huntsman Corporation) B3-1 – Ajicure PN-23J – amine adduct (solid, Ajinomoto) Component (C): Initiator system for radical polymerization C1-1 – Irgacure TPO-L – ethyl (2,4,6-trimethylbenzoyl)phenylphosphinate (IGM Resins) C1-2 – Irgacure TPO – trimethylbenzoyldiphenylphosphine oxide (IGM Resins) C2-1 – TBPND – tert-butyl peroxyneodecanoate (United Initiators) C2-2 – Peroxane APO – tert-amyl peroxy-2-ethylhexanoate (Pergan) Component (D): Additional radically curable component D-1 – SR350D – Trimethylolpropane trimethacrylate (Arkema) D-2 – SR324 – C16-C18 methacrylate (Arkema) D-3 – SR834 – Tricyclodecanedimethanol dimethacrylate (Arkema) D-4 – VISIOMER IBOMA – Isobornyl methacrylate (Evonik Industries) Component (E): Additives E-1 – AMMO – 3-Aminopropyltrimethoxysilane (adhesion promoter) (Evonik Industries) E-2 – HQMME –Hydroquinone monomethyl ether (stabilizer) (Sigma Aldrich) E-3 – Special black – dye (Palmer Holland) E-4 – Tinuvin 292 – HALS (BASF SE) E-5 – Triisododecyl phosphite – (Sigma Aldrich) E-6 – Cab-O-Sil TS720 – fumed amorphous silica (Cabot Corporation) E-7 – Denka Fused Silica FB-74 – quartz (Denka Company Ltd.) E-8 – bismuth neodecanoate (Sigma Aldrich) E-9 – Aerosil R-805 – fumed amorphous silica (Evonik Industries) The curable compositions were formulated with the proportions of components (A) to (E) stated in Tables 1 to 3 below. Inventive examples 1 to 15 were compared with comparative examples 1 to 4. The proportions of the components are given in wt.%, based on the total weight of the mass.

[0002] 6 l e i p 8 , 2 41 , 4 , 8 6 , 6 , 6 , 1 , 3 , 6 0 4, 3 , 0 5 2 , 8 , 8 2 1 si e 4 0 0 4 1 0 0 1 1 0 0 0 4 , 0 4 2 2 7 - B 5 l e i p 2 4 , 8 1 , 5 1 9 6 1 si 8 , e 0 7 6 , 2 1 1 7 1 , 0 , 50 , 20 , 20 , 0 1 4 , 0 , 36 , 2 3 9 7 - B 4 l e i p si 8 2 , 4 , 8 e0 7 6 , 2 1 1 9 1 5 , 1 1 0 1 4 9 0 , 0 6 , 0 , 5 , 9 0 1 6 - B 3 l e i p 2 , 2si 0 , 2 , 8 , 1 1 5 , 1 , 1 1 3 8 , 5 , 3 6 7 e 1 0 3 8 2 0 0 , 0 3 5 1 4 - B 2 l e i 9 , 2 5 , 8 8 5 1 5 7 4 9 , 9 5 - p si 7 , 0 3 6 , 2 4 1 1 1 , 0 , 0 1 , 0 , 6 8 1 1 1 6 -0 e 4 B - - s h c 2 and l yes l e i g p 8 2 , 4 , 8 r s 0 7 , 2 1 9 1 5 , 1 5 0 , 1 7 , 1 , 8 ,6 ) 2 ) 2ei 6 0 0 0 1 V e b - . s and h 1 l l c and i e i 9 , 2 5 , 8 i e 8 5 1 ) 2 2 8 2p l g p si 1 1 , 0 3 6 , 2 1 1 1 , 0 , 0 1 1 - , 7 , 3 7 7 - s i r e e and V b b s h c i 1 and l l e g i r p 8 2 , 4 , 8 , 1 1 8 5 , 1 , 1 5 7 5 , 6 , 8 8 6 and si e 0 7 6 2 1 0 0 , 0 4 8 9 - V d B n u ie l ] a e b e i P p s M i [ e u l ] ] B A a g P e i % [ : - t h ] 1 s a M [ s n e l 2 a P l l G u e r l a s 7 M b a a e A - t r e ( u ä ti b l u T 1 1 - 2 - h - 1 S l A s o ü C d o ] C ° 1 - 2 2 - 2 - 1 - 2 - 1 - 1 - 1 - 1 - - 1 2 3 4 5 6 7 e i F S ks i ° M [ A A 1 B 1 B 2 B 2 B 3 B 1 C 2 C D - E - E - E - E - E - E - E D D V 3 2- E g T 2 1 l e i p 0 s i 1 5 52 , 3 , 8 0 0 , 2 5 1 1 1 8 1 5 , 0e5 B 1 1 l e i p 5 s , 5 51 i 5 , 2 , 9 4 , 51 , 0 2 8 2 1 and 0 5 B - s h c 4 i l and l e i p 5 4 1 , 5, 8 5 1 9 , 1 1 8 1 , g r si 2 2 0e V e b 0 1 l e i 2 p 3 4 s , 1 1 , 5 5 1 , and , 7 0 9 5 1 1 1 8 0e B 9 l e i - p 6 2 8 , 8 si , e 9 , 0 5 6 , 2 1 1 8 1 5 , 01 4 B - 8 l e i p si 8 2 , 4 , 1 7 8 , 1 1 , 5 , e 0 6 2 8 1 0 B - . s 3 e h l c e i l e i 9 2 3 , 5 ie l p , , 0 1 1 8 1 , p g rsi 7 0 7 0 s i e e have been V b b s h r c a i 7 b e l s l e i 5 4 , 2 , 8 , 5 , 5 , s g r p have been si 1 e0 0 6 2 1 1 8 1 0 e m V B t d h n c i n, r u g a e l n b e i i r m p s i e g mi t e B u s z e : 2 t b r t e no h c l )1 W i e ) 2 n b and T 1 3 1 2 1 2 1 -1 - - - - - - 1 2 2 2 3 4 1 1 2 1 2 1 1 2 - 1 - 1 - 1 - 1 - 2 - - - - - - - 1-2-3-1A A A B B B B B 2 B 2 B 3 B 1 C 1 C 2 C 2 C D D D - E 1 , 3 5 4 , 0 , 6 7 0 1 , 0 9 3 1 0 1 6 -2 , 3 4 2 0 , 2 1 0 2 , 1 , 6 0 2 0 2 6 -1 , 0 1 )2 - )2 - )2 - )2 - )2 - 3 7 0 9 , 4 5 0 , 0 , 0 , 6 2 5 1 7 7 -1 , 1 1 8 7 , 1 , 2 7 - 0 , 0 38 1 5 5 -2 4 -1 0 6 , 7 2 , 4 7 0 , 3 2 2 0 1 6 -1 , )1 8 , 8 , 0 6 0 1 - 6 4 5 5 - s u a t 1 , 5 , 3 6 1 , 0 , 2 r e t 2 6 a r b ä 0 0 , 0 5 3 1 3 5 - s h s , e r a m b l ] i t l a e h e c t s P b i n r M , e [ g h t u l ] ] ni r h c A a g - s P e i % t [e i n a h ] g ff l M [ s n 2 a P u o G r u l a a e A s - t 7 ä r z t e M ( t t r s b l u e b e l h u S l i A s o ü C d o ] C ° ) 1 W ) 2 K 2 6 8 9 - e F k s ° [ - E - E - E - E i D S D i V 3 M 2 - E g TAccording to the preferred embodiments, Examples 1 to 12 according to the invention each contain an at least difunctional, passivated and solid isocyanate (A), an isocyanate-reactive component (B) comprising at least one hybrid compound (B1), and an initiator system for radical polymerization (C), consisting of a radical photoinitiator as the first photoinitiator (C1) and a radical initiator for heat curing as the second initiator (C2). The compositions according to the invention can be fixed by means of light and achieve initial strengths (glass / aluminum) of more than 0.3 MPa. During heat curing, compressive shear strengths (aluminum / aluminum) of at least 2.5 MPa are achieved. The composition according to Example 1 contains, in addition to the obligatory constituents, a second liquid isocyanate-reactive component (B2) as a chain extender, an additional radically curable component (D), and an additive (E).The measured light-curing strength is 0.75 MPa. After final heat curing, the cured compound achieves a compressive shear strength of 4.5 MPa. By adding an amine (B3-1, Example 2) that is solid at room temperature, i.e., an additional solid isocyanate-reactive component (B3), the compressive shear strength can be increased to 6.4 MPa, while maintaining a consistently high light-curing strength of 0.75 MPa. The compounds according to Comparative Examples 1 and 3 do not contain the hybrid compound (B1), and light-curing strength after irradiation is not measurable. Heat-curing of the compounds is still possible without restriction. If the second initiator (C2), i.e., the radical initiator for heat curing, is omitted, as shown in Comparative Example 2, sufficient adhesion cannot be established in shadow zones. The compressive shear strength is 0.1 MPa.Even without the addition of additional radically curable components (D), as in Example 3, a light-fixation strength of 0.31 MPa is achieved by the radically curable groups of the hybrid compound (B1). Inventive Examples 4 to 6 show various blends of additives. In Example 7, a difunctional hybrid (B1-1-3) with an amino group and a methacrylate group is used. The composition meets all technical requirements. In Example 8, the addition of the stabilizer (E-2) is omitted. Processing of the compositions remains unrestricted. Examples 9 and 10 each contain the hydroxy-functional hybrid compound (B1-2-1). In Example 11, an alternative polyisocyanate (A1) is used. Comparative Example 4 contains a hybrid compound (B1) with a hydroxy group and a methacrylate group (B1-2-2). The molar mass of compound B1-2-2 is less than 400 g / mol.The reference compound had already cured during production; processing was not possible. Example 11 shows a variation of several components. The compound achieves a high light-fixation strength of 1.43 MPa. In Example 12, a second liquid isocyanate-reactive component (B2) is added. The cured compound achieves a compressive shear strength of 9.4 MPa. Table 3: Volume changes of exemplary compounds. K. omponente Example 13 Example 14 Example 15A 1-1 6.93 6.45 5.97A 2-1 0.21 0.19 0.18B 1-2-2 77.36 67.86 58.35B 2-2 1.5 1.5 1.5C 1-1 1 1 1 C 2-1 1 1 1 D -4 10 20 30 E -6 2 2 2Volume shrinkage [%] -0.83 0.24 1.68 Examples 13 to 15 show a series of measurements to monitor the volume change of the curable compound during curing. By adding increasing amounts of the additional radically curable component (D), the density of the radically curable network can be increased and the volume expansion caused by thermal isocyanate curing can be counteracted. Compounds can be formulated with either volume expansion or volume reduction (shrinkage). In extreme cases, the volume shrinkage of the compound after curing can be zero.

Claims

Patent claims 1. A composition which can be fixed with actinic radiation and cured by heat, comprising (A) an at least difunctional passivated and solid isocyanate, (B) an isocyanate-reactive component which comprises at least one liquid hybrid compound (B1) which, in addition to at least one isocyanate-reactive group, contains at least one free-radically curable group, the hybrid compound (B1) having a molecular weight of at least 400 g / mol; and (C) an initiator system for free-radical polymerization which comprises a first initiator (C1) and a second initiator (C2), the first initiator (C1) being a free-radical photoinitiator and the second initiator (C2) being a free-radical initiator for heat curing.

2. The composition according to claim 1, wherein the at least one radically curable group of the hybrid compound (B1) is selected from the group consisting of (meth)acrylate, allyl ether, vinyl ether, isoprenyl, and butadienyl groups, and combinations thereof. 3.The composition according to claim 1 or 2, wherein the at least one isocyanate-reactive group of the hybrid compound (B1) is selected from the group consisting of amino and hydroxyl groups, and combinations thereof.

4. The composition according to any one of the preceding claims, wherein the at least one isocyanate-reactive group of the hybrid compound (B1) is bonded to a primary or secondary carbon of the hybrid compound (B1).

5. The composition according to any one of the preceding claims, wherein the hybrid compound (B1) contains at least one primary amino group as an isocyanate-reactive group and at least one (meth)acrylate group, in particular a methacrylate group, as a radically curable group.

6. The composition according to any one of the preceding claims, wherein the average functionality of the hybrid compound (B1) is at least three, based on the number of isocyanate-reactive and free-radically curable groups of the hybrid compound (B1).

7. The composition according to any one of the preceding claims, wherein the hybrid compound (B1) has a molecular weight in the range from 400 g / mol to 20,000 g / mol, more preferably from 500 to 19,000 g / mol, particularly preferably from 600 to 18,000 g / mol.

8. The composition according to any one of the preceding claims, wherein the second initiator (C2) is selected from the peroxo compounds and / or benzpinacols.

9. A composition according to any one of the preceding claims, wherein the curable composition comprises the following components: (A) 1 to 40% by weight of the at least difunctional passivated and solid isocyanate, (B) 5 to 90% by weight of the isocyanate-reactive component, (C) 0.01 to 5% by weight of the first initiator (C1) and 0.01 to 10% by weight of the second initiator (C2), (D) 0 to 50% by weight.-% of a further free-radically curable component, and (E) 0 to 80 wt. % of additives (E), based in each case on the total weight of the curable composition.

10. A process for joining, casting, and / or coating substrates using a curable composition according to one of the preceding claims, comprising the following steps: a) metering the curable composition onto a first substrate; b) optionally supplying a second substrate to form a substrate composite; c) fixing the curable composition with actinic radiation; and. d) Heat-curing the fixed mass on the substrate or in the substrate composite by heating to a temperature of at least 60 °C.

11. Use of a curable mass according to one of claims 1 to 9 for joining, encapsulating, and / or bonding electronic and optoelectronic components, in particular for producing camera modules or LIDAR systems.