Photopolymerizable adhesive composition for the encapsulation of electronic or optoelectronic devices

Abstract

The present invention relates to adhesive photopolymerizable compositions used in the encapsulation of electronic and optoelectronic devices, in particular flexible electronic and optoelectronic devices, for example photovoltaic cells, in order to protect them against permeation to gases and moisture. Figure 3

Description

Title of the invention: Adhesive photopolymerizable composition for encapsulation of electronic or optoelectronic devices technical field

[0001] The present invention relates to adhesive photopolymerizable compositions used in the encapsulation of electronic and optoelectronic devices, in particular flexible electronic and optoelectronic devices, for example organic photovoltaic cells, in order to protect them against permeation to gas and moisture. TECHNICAL BACKGROUND

[0002] There are different types of electronic or optoelectronic devices, including rigid or flexible electronic or optoelectronic devices.

[0003] Rigid electronic or optoelectronic devices can be of different kinds depending on the applications considered, such as display applications (for example OLEDs and QLEDs), photovoltaic applications (for example silicon-based semiconductors, CIGS, CDTE, organic semiconductors, Perovskite-type semiconductors) or sensors.

[0004] Flexible electronic or optoelectronic devices can be defined according to the same application examples but for semiconductor technologies compatible with the use of flexible substrates such as organic light-emitting diode (OLED) devices, organic photovoltaic (OPV) cells, amorphous silicon (a-Si) cells, CIGS, perovskite-type semiconductors, organic transistors (OFETs) or organic sensors using organic semiconductors.

[0005] Electronic or optoelectronic devices are sensitive to multiple factors, for example, light, heat, oxygen (air), humidity, pressure, shocks, etc. To ensure optimal efficiency and performance and to achieve satisfactory durability, they must therefore be protected and isolated from their environment. This protection must be all the more effective the more sensitive the constituent materials are to the atmosphere, particularly water and oxygen. This is especially true when using organic semiconductors, for example, perovskite semiconductors or CIGS semiconductors.

[0006] Various encapsulation techniques have been implemented. These generally include coating the device with an adhesive composition for The process involves obtaining an encapsulated device, then laminating the encapsulated device between two covers to create an encapsulated device. The choice of adhesive composition and covers will depend on the devices to be encapsulated. Furthermore, depending on the composition and covers used, the resulting electronic or optoelectronic modules will have specific properties, particularly in terms of weight, thickness, transparency / opacity, rigidity / flexibility, gas and liquid permeability / tightness, impact resistance, and / or durability / aging.

[0007] In view of the layered arrangement, two types of permeation can be observed, orthogonal permeation at the level of the external surface of the hoods between which the coated devices are intercalated, and lateral permeation at the level of the free edge of the adhesive within the coating material as well as at the interface of the two hoods.

[0008] The protection of the device against lateral permeation is ensured in particular by the adhesive or encapsulating material, the effectiveness of which can depend on various factors, including its chemical formulation, its application process, its thickness (proportional to the surface area exposed to the environment), its interface with the covers, its resistance to usage stresses, etc. The properties of the adhesive must therefore be optimized to minimize or even eliminate lateral permeation, to ensure optimal efficiency and performance, and to achieve satisfactory durability.

[0009] Flexible photovoltaic cells (e.g., organic, perovskite, CIGS, CDTE cells) represent a particularly attractive alternative to rigid silicon-based photovoltaic cells, as they can be manufactured using continuous, high-speed processes (roll-to-roll process) and are suitable for applications requiring flexibility, conformability, or low weight. They are also less fragile (using flexible covers) and less susceptible to breakage.

[0010] Flexible photovoltaic cells can for example be obtained by low-temperature printing of a thin active layer (organic material or perovskite having semiconducting properties) deposited on a flexible polymeric support substrate.

[0011] The encapsulation of a flexible electronic or optoelectronic device can be achieved by means of a hood that is not very permeable to gases, in particular to water vapor and oxygen, which must be at least as flexible as the device it protects so as not to become a limiting factor in the bending of the latter, or it must exhibit controlled flexibility when, for example, the encapsulation is used to knowingly limit the radius of curvature of the device and to prevent its damage.

[0012] There is therefore a real need to provide an adhesive composition enabling the production of electronic or optoelectronic modules having properties Satisfactory properties are required, particularly adhesive, optical, thermal, electrical, gas barrier, elastic, and strength properties. There is also a need for an adhesive composition suitable for encapsulating flexible electronic or optoelectronic devices. Furthermore, there is a need for an adhesive composition that enables the production of electronic or optoelectronic modules with limited photoaging (e.g., yellowing). Additionally, there is a need for an adhesive composition that enables the production of electronic or optoelectronic modules with limited lateral gas and water permeation. Finally, there is a need for an adhesive composition that enables the production of electronic or optoelectronic modules with optimal efficiency and performance, and satisfactory durability. Summary of the invention

[0013] The invention relates primarily to an adhesive photopolymerizable composition comprising, by total weight of the adhesive photopolymerizable composition: - from 20 to 35% of at least one block copolymer; - 45 to 75% of at least one (meth)acrylate monomer having a glass transition temperature (Tg) of at least 85°C; - 2 to 15% of at least one alkoxysilane (meth)acrylate monomer; and - 0.1 to 5% of at least one photoinitiator.

[0014] In embodiments, the block copolymer is chosen from the group consisting of block copolymers comprising at least one block M and at least one block B; said block M designating a polymer block comprising at least 50% by weight of methyl methacrylate; and block B designating an elastomeric polymer block incompatible with block M, and whose glass transition temperature is less than 20°C.

[0015] In embodiments, the (meth)acrylate monomer having a glass transition temperature of at least 85°C is selected from the group consisting of methyl methacrylate, tert-butyl methacrylate, phenyl methacrylate, isopropyl methacrylate, isobornyl methacrylate, isobomyl acrylate, cyclohexyl methacrylate, 4-ter-butylcyclohexyl methacrylate, dihydrodicyclopentadienyl acrylate and mixtures thereof.

[0016] In embodiments, the alkoxysilane (meth)acrylate monomer is chosen from the group consisting of trialkoxysilane (meth)acrylate monomers.

[0017] In embodiments, the adhesive photopolymerizable composition further comprises at least one (meth)acrylate monomer having a glass transition temperature below 0°C, a methacrylic acid monomer, at least an oligomer urethane (meth)acrylate, at least one monofunctional reactive diluent and mixtures thereof.

[0018] In embodiments, the (meth)acrylate monomer having a glass transition temperature below 0°C, if present, is selected from the group consisting of butyl acrylate, ethyl acrylate, propyl acrylate, hexyl acrylate, octyl acrylate, dodecyl acrylate, isopropyl acrylate, isobutyl acrylate, isodecyl acrylate, 2-ethylhexyl acrylate, 2-propylheptyl acrylate, isodecyl methacrylate, dodecyl methacrylate, 2-hydroxyethyl acrylate and mixtures thereof.

[0019] The invention relates secondly to an adhesive product comprising the photopolymerizable adhesive composition as described opposite and an opaque container containing it.

[0020] The invention relates thirdly to an adhesive obtained by the process comprising the following steps: - application of a photopolymerizable adhesive composition as described opposite on at least one cover and / or an electronic or optoelectronic device; - photopolymerization of the applied photopolymerizable adhesive composition to obtain a polymerized adhesive; and - optionally shaping of the polymerized adhesive.

[0021] The invention relates fourthly to an electronic or optoelectronic module comprising the assembly of a series of layers including, in this order: - a first hood; - a first adhesive as described opposite or obtained from the photopolymerizable adhesive composition as described opposite; - a flexible electronic or optoelectronic device; - a second adhesive as described opposite or obtained from the photopolymerizable adhesive composition as described opposite; and - a second cap.

[0022] In embodiments, the flexible electronic or optoelectronic device is chosen from organic light-emitting diodes, organic photovoltaic cells, organic transistors, or organic sensors.

[0023] In some embodiments, the flexible electronic or optoelectronic device is a perovskite-type device.

[0024] The invention relates fifthly to a method for obtaining the module as described opposite, the method comprising the following steps: - the provision of an electronic or optoelectronic device; - the supply of a photopolymerizable adhesive composition as described opposite; - the supply of a first hood; - the supply of a second hood; - the application of layers of adhesive photopolymerizable composition on the surface of the device and / or on respective internal surfaces of the first and second caps; - the lamination of the device and the layers of adhesive photopolymerizable composition between the respective internal surfaces of the first and second caps; and - the photopolymerization of layers of adhesive photopolymerizable composition.

[0025] The invention relates sixthly to the use of the photopolymerizable adhesive composition as described opposite, or of the adhesive as described opposite, for the encapsulation of flexible electronic or optoelectronic devices.

[0026] The inventors have demonstrated in a surprising way that the adhesive photopolymerizable composition according to the present invention, after application and photopolymerization, exhibits very satisfactory, even excellent, properties, in particular adhesive, optical, thermal, electrical, barrier, elastic and resistance properties.

[0027] In addition, the invention also has one or preferably several of the following advantages: - obtaining electronic or optoelectronic modules with satisfactory properties, in particular satisfactory adhesive, thermal, optical, electrical, gas barrier, elastic and resistance properties - satisfactory encapsulation of flexible electronic or optoelectronic devices; - obtaining electronic or optoelectronic modules exhibiting time-limited photoaging (e.g., yellowing) - the production of electronic or optoelectronic modules exhibiting time-limited lateral permeation to gases and water; and - obtaining electronic or optoelectronic modules ensuring optimal efficiency and performance and exhibiting satisfactory durability. BRIEF DESCRIPTION OF THE FIGURES

[0028] [Fig.1] corresponds to the photographs and corresponding images obtained after computer analysis of the modules tested in test 1.

[0029] [Fig.2] represents a graph concerning the rate of degradation as a function of the modules tested according to test 1.

[0030] [Fig.3] corresponds to the photographs of the modules tested in test 2.

[0031] [Fig.4] represents a graph concerning the percentage of transmission of modules tested according to wavelength (nm) according to test 3. DETAILED DESCRIPTION

[0032] The invention is now described in more detail and in a non-limiting manner in the following description.

[0033] By "flexible" or "supple", we mean the ability of a material, in particular due to its intrinsic properties and / or its small thickness, to bend, curve and / or fold easily.

[0034] By "flexible electronic or optoelectronic device" (and the module obtained from it), we mean a device (a module) retaining its electronic conductive or semiconductive properties even when bent with a very small radius of curvature without risk of buckling or delamination of the electronic components.

[0035] The term "adhesive" refers to the matrix / structure formed around the electronic or optoelectronic device by the photopolymerized adhesive composition. The terms "adhesive" and "encapsulant" are currently used interchangeably.

[0036] By "module", we mean the assembly of the electronic or optoelectronic device coated by the polymerized adhesive composition and interposed between the two hoods.

[0037] The term "hood" refers to the elements between which the encapsulated electronic or optoelectronic device is laminated. Currently, this element may be referred to interchangeably as "support", "plate" or "sheet".

[0038] By "photopolymerizable composition" or "photocrosslinkable composition" is meant a composition for which the initiation (priming) of polymerization is triggered by exposure to electromagnetic radiation, in particular to ultraviolet (UV) radiation.

[0039] By "monomer" is meant a molecule that can undergo polymerization. When the term "monomer" is used to designate a constituent of a polymer, it means the unit (or residue) derived from the monomer - or monomer unit / momeric unit - by polymerization with at least one other monomer.

[0040] By "polymerization" is meant a process of transforming a single type of monomer or a mixture of different types of monomers into a polymer.

[0041] By "polymer" is meant a copolymer or a homopolymer.

[0042] By "homopolymer" is meant a polymer comprising several units identical monomers.

[0043] By “copolymer” we mean a polymer combining at least two different types of monomer units (designated co-monomers).

[0044] By "oligomer" we mean a small polymeric compound, obtained by polymerization of 2 and 30 monomers (comprising from 2 to 30 monomer units), that is to say whose degree of polymerization is between 2 and 30.

[0045] By "block copolymer" is meant a polymer comprising one or more uninterrupted sequences of each of the distinct polymer species, the polymer sequences being chemically different from one another and being linked together by a covalent bond. These polymer sequences are also called polymer blocks.

[0046] The term "(meth)acrylic" (or "(meth)acrylate") means any type of acrylic and / or methacrylic (or acrylate and / or methacrylate) compounds, polymers, monomers or oligomers. For example, (meth)acrylic acid means acrylic acid or methacrylic acid, isobornyl (meth)acrylate means isobornyl acrylate or isobornyl methacrylate, etc.

[0047] By “polymerization” we mean a chemical process which allows molecules to be linked together to form a three-dimensional network.

[0048] By "initiator" or "starter" is meant a chemical species which reacts with a monomer to form an intermediate compound capable of successfully binding to a large number of other monomers to form a polymer or which reacts with polymers to initiate the process of molecular interconnection known as polymerization.

[0049] By "Tg", we mean the glass transition temperature. The glass transition temperature can be measured by differential scanning calorimetry (DSC), for example using the mid-height tangent method measured between two inflection points located between the 3rd heating cycle between 40 and 140°C.

[0050] By "ambient temperature" is meant a temperature of about 20°C.

[0051] By "substantially free of" is meant a composition comprising less than 1%, preferably less than 0.1%, preferably less than 0.01%, preferably about 0%, of a compound, by total weight of the composition. Adhesive photopolymerizable composition

[0052] In a first aspect, the present invention relates to an adhesive photopolymerizable composition. block copolymer

[0053] The composition comprises at least one block copolymer, preferably at least one (meth)acrylic block copolymer.

[0054] The composition may comprise from 20 to 35%, preferably from 25 to 30%, of at least one block copolymer, by total weight of the composition. The composition may comprise, for example, from 20 to 21%, alternatively from 21 to 22%, alternatively from 22 to 23%, alternatively from 23 to 24%, alternatively from 24 to 25%, alternatively from 25 to 26%, alternatively from 26 to 27%, alternatively from 27 to 28%, alternatively from 28 to 29%, alternatively from 29 to 30%, alternatively from 30 to 31%, alternatively from 31 to 32%, alternatively from 32 to 33%, alternatively from 33 to 34%, alternatively from 34 to 35%, of at least one block copolymer, by total weight of the composition.

[0055] By "(meth)acrylic block copolymer" is meant a (meth)acrylic block copolymer comprising 10% or less (for example, from 0.1 to 10%), preferably 5% or less (for example, from 0.1 to 5%), of at least one non-(meth)acrylic monomer, by total weight of the copolymer. The non-(meth)acrylic monomer may be selected from the group consisting of butadiene, isoprene, styrene, vinylnaphthalene, a cyclosiloxane monomer, vinylpyridine, and their derivatives (for example, α-methylstyrene or β-butylstyrene).

[0056] The block copolymer can be selected from block copolymers comprising at least one M block and at least one B block, in particular block copolymers having the diblock BM structure (or diblock BM copolymer) or the triblock MBM structure (or triblock MBM copolymer), in which each block is linked to the other by means of a covalent bond or an intermediate molecule linked to one of the blocks by a covalent bond and to the other block by another covalent bond. The block copolymer is preferably a triblock MBM copolymer.

[0057] Block M designates a polymer block comprising at least 50% by weight of methyl methacrylate. Block M may designate a homopolymer block of polymethyl methacrylate (PMMA - 100% by weight of methyl methacrylate) or a copolymer block comprising at least 50% by weight of methyl methacrylate and 50% or less of another monomer, other than methyl methacrylate, by total weight of block M.

[0058] Block B designates an elastomeric polymer block incompatible with block M, and whose glass transition temperature (Tg) is lower than room temperature, preferably lower than 0°C, preferably lower than -20°C.

[0059] With regard to the diblock copolymer BM, block M may consist of methyl methacrylate monomers. Alternatively, block M may comprise at least 50% (e.g. from 50 to 99.9%), preferably at least 75% (e.g. from 75 to 99.9%), of methyl methacrylate; and 50% or less (e.g. from 0.1 to 25%), preferably 25% or less (e.g. from 0.1 to 25%), of at least one other monomer other than methyl methacrylate, by total weight of block M.

[0060] The other monomer, different from methyl methacrylate, constituting block M, may be another (meth)acrylic monomer or a non-(meth)acrylic monomer.

[0061] The non-(meth)acrylic monomer can be chosen from the group consisting of butadiene, isoprene, styrene, vinylnaphthalene, a cyclosiloxane monomer, vinylpyridine and their derivatives (for example α-methylstyrene or β-butylstyrene).

[0062] The other (meth)acrylic monomer may be selected from the group consisting of methyl acrylate, ethyl (meth)acrylate, (meth)acrylic acid, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, (meth)acrylic acid derivative amides (e.g., N,N-dimethylacrylamide), 2-methoxyethyl (meth)acrylate, 2-aminoethyl (meth)acrylate, polyethylene glycol (PEG) (meth)acrylate, wherein the PEG group has a molar mass from 400 to 10,000 g / mol, and mixtures thereof.

[0063] The elastomeric block B may be made of alkyl (meth)acrylate monomer. Alternatively, block B may comprise at least 95% (for example, from 95 to 99.9%) of alkyl (meth)acrylate; and 5% or less (for example, from 0.1 to 5%) of another monomer other than alkyl (meth)acrylate, by total weight of block B.

[0064] The alkyl (meth)acrylate can be chosen from the group consisting of ethyl acrylate (Tg = -24°C), butyl acrylate (-54°C), 2-ethylhexyl acrylate (-85°C), hydroxyethyl acrylate (-15°C), 2-ethylhexyl methacrylate (-10°C) and mixtures thereof; preferably the alkyl (meth)acrylate is butyl acrylate.

[0065] The other monomer, different from alkyl (meth)acrylate, can be chosen from the group consisting of butadiene, isoprene, styrene, vinylnaphthalene, a cyclosiloxane monomer, vinylpyridine and their derivatives (for example α-methylstyrene or β-butylstyrene).

[0066] The dibloc BM copolymer can have a number-average molar mass between 10,000 and 500,000 g / mol, preferably between 20,000 and 200,000 g / mol.

[0067] The diblock copolymer BM may comprise a mass fraction (by total weight of the copolymer) of between 5 and 95%, preferably between 15 and 85%, in block M; and between 5 and 95%, preferably between 15 and 85%, in block B.

[0068] With regard to the MBM triblock copolymer, the two M blocks are made up of the same monomers (or co-monomers) as the M block of the BM diblock copolymer as described above. These two M blocks may be identical or different. For example, these two M blocks may differ in their molar mass, but be made up of the same monomers.

[0069] Block B consists of the same monomers (or co-monomers) as block B of the dibloc BM copolymer as described above.

[0070] The MBM triblock copolymer can have a number-average molar mass of between 10,000 g / mol and 500,000 g / mol, preferably between 20,000 and 200,000 g / mol.

[0071] The MBM triblock copolymer may comprise a mass fraction (by total weight of the copolymer) of between 10 and 80%, preferably between 15 and 70%, preferably between 40 and 60%, in M ​​blocks; and between 20 and 90%, preferably between 30 and 85%, preferably between 40 and 60%, in B blocks. An example of an MBM triblock copolymer is a polymethyl methacrylate-poly(styrene-co-butylacrylate)-polymethyl methacrylate block copolymer.

[0072] Block copolymers can be manufactured by controlled radical polymerization (CRP), for example according to the processes as described in PCT applications WO 96 / 24620 A and WO 00 / 71501 Al, or by anionic polymerization.

[0073] One or less of blocks M and B can be functionalized by means of one or more functions chosen from the group consisting of acid, amine, amide, epoxy, thiol functions, quaternary ammonium groups, chlorinated groups and fluorinated groups.

[0074] Block copolymers are commercially available under the name Nanostrength® from Arkema. (Meth)acrylate monomers

[0075] The composition comprises at least one (meth)acrylate monomer having a glass transition temperature (Tg) of at least 85°C.

[0076] The composition may comprise from 45 to 75%, preferably from 45 to 70%, preferably from 45 to 65%, of at least one (meth)acrylate monomer having a glass transition temperature of at least 85°C, by total weight of the composition.The composition may include, for example, 45 to 46%, alternatively 46 to 47%, alternatively 47 to 48%, alternatively 48 to 49%, alternatively 49 to 50%, alternatively 50 to 51%, alternatively 51 to 52%, alternatively 52 to 53%, alternatively 53 to 54%, alternatively 54 to 55%, alternatively 55 to 56%, alternatively 56 to 57%, alternatively 57 to 58%, alternatively 58 to 59%, alternatively 59 to 60%, alternatively 60 to 61%, alternatively 61 to 62%, alternatively 62 to 63%, alternatively 63 to 64%, alternatively 64 to 65%, alternatively 65 to 66%, alternatively 66 to 67%, alternatively 67 to 68%, alternatively 68 to 69%, alternatively 69 to 70%, alternatively 70 to 71%, alternatively 71 to 72%, alternatively 72 to 73%, alternatively 73 to 74%, alternatively 74 to 75%, of at least one (meth)acrylate monomer. having a glass transition temperature of at least 85°C, by total weight of the composition.

[0077] The (meth)acrylate monomer having a glass transition temperature of at least 85°C can be chosen from the group consisting of methyl methacrylate, tert-butyl methacrylate, phenyl methacrylate, isobornyl methacrylate, isobornyl acrylate, cyclohexyl methacrylate, 4-ter-butylcyclohexyl methacrylate, dihydrodicyclopentadienyl acrylate and mixtures thereof; preferably the (meth)acrylate monomer having a glass transition temperature of at least 85°C is methyl methacrylate. Alkoxysilane (meth)acrylate monomers

[0078] The composition comprises at least one alkoxysilane (meth)acrylate monomer.

[0079] The composition may comprise from 2 to 15%, preferably from 3 to 10%, preferably from 4 to 6%, of at least one alkoxysilane (meth)acrylate monomer, by total weight of the composition. The composition may comprise, for example, from 2 to 3%, alternatively from 3 to 4%, alternatively from 4 to 5%, alternatively from 5 to 6%, alternatively from 6 to 7%, alternatively from 7 to 8%, alternatively from 8 to 9%, alternatively from 9 to 10%, alternatively from 10 to 11%, alternatively from 11 to 12%, alternatively from 12 to 13%, alternatively from 13 to 14%, alternatively from 14 to 15%, of at least one alkoxysilane (meth)acrylate monomer, by total weight of the composition.

[0080] The alkoxysilane (meth)acrylate monomer, including the alkyl alkoxysilane (meth)acrylate monomer, can be selected from the group consisting of the trimethoxysilane (meth)acrylate monomers; preferably from the trimethoxysilane (meth)acrylate monomers; preferably the alkoxysilane (meth)acrylate monomer is selected from the group consisting of 3-(trimethoxysilyl)propyl acrylate, 3-(trimethoxysilyl)propyl methacrylate, trimethoxysilyl acrylate, trimethoxysilyl acrylate and mixtures thereof; preferably the alkoxysilane (meth)acrylate monomer is trimethoxysilyl acrylate.

[0081] Trimethoxysilane acrylate is commercially available under the name Silquest® A174 from Momentive®. Photo-primer

[0082] The composition includes at least one photoinitiator. Any compound capable of initiating the photopolymerization of the adhesive composition, in particular any compound capable of initiating the radical polymerization of urethane (meth)acrylate monomers and / or oligomers by irradiation with ultraviolet (UV) or visible light, to obtain the adhesive, may be used.

[0083] The composition may comprise from 0.1 to 5%, preferably from 0.5 to 4%, preferably from 1 to 3%, of at least one photoinitiator, by total weight of the composition. The composition may comprise, for example, from 0.1 to 1%, alternatively from 1 to 2%, alternatively from 2 to 3%, alternatively from 3 to 4%, alternatively from 4 to 5%, of at least one photoinitiator, by total weight of the composition.

[0084] The photoinitiator may be selected from the group consisting of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, triethylbenzoyl-diphenylphosphine oxide, thioxanthen-9-one, 4,4-bis(diethylamino)benzophenone, 9,10-phenanthrene quione, benzoyltrimethylgermane, dibenzoyldiethylgermane, bis-(4-methoxybenzoyl)diethylgermanium, and mixtures thereof; preferably phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide. One mixture may include, for example, benzophenone, α-hydroxyketone, and triethylbenzoyl-diphenylphosphine oxide. Another mixture may include, for example, benzoyltrimethylgermane, dibenzoyldiethylgermane, and bis-(4-methoxybenzoyl)diethylgermanium.

[0085] Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide is commercially available under the name Irgacure® 819 from Ciba® Specialty Chemicals. The mixture comprising benzophenone, α-hydroketone, and triethylbenzoyl-diphenylphosphine oxide is commercially available under the name Esacure® KTO 46 from Lehvoss. Other monomer (meth)acrylate

[0086] The composition may include at least one (meth)acrylate monomer having a glass transition temperature (Tg) below 0°C. In this embodiment, the composition comprises a mixture of a (meth)acrylate monomer having a glass transition temperature of at least 85°C and a (meth)acrylate monomer having a glass transition temperature below 0°C.

[0087] The composition may comprise from 0 to 5% of at least one (meth)acrylate monomer having a glass transition temperature below 0°C, by total weight of the composition. If present, the composition may comprise from 0.1 to 5% of at least one (meth)acrylate monomer having a glass transition temperature below 0°C, by total weight of the composition. The composition may comprise, for example, from 0 to 1% (from 0.1 to 1%), alternatively from 1 to 2%, alternatively from 2 to 3%, alternatively from 3 to 4%, alternatively from 4 to 5%, of at least one (meth)acrylate monomer having a glass transition temperature below 0°C, by total weight of the composition.

[0088] The (meth)acrylate monomer having a glass transition temperature below 0°C can be chosen from the group consisting of butyl acrylate, ethyl acrylate, propyl acrylate, hexyl acrylate, octyl acrylate, acrylate dodecyl, isopropyl acrylate, isobutyl acrylate, isodecyl acrylate, 2-ethylhexyl acrylate, 2-propylheptyl acrylate, isodecyl methacrylate, dodecyl methacrylate, 2-hydroxyethyl acrylate and mixtures thereof; preferably butyl acrylate.

[0089] Alternatively, the composition may be substantially devoid of (meth)acrylate monomers having a glass transition temperature (Tg) below 0°C. Methacrylic acid

[0090] The composition may include a methacrylic acid monomer.

[0091] The composition may comprise from 0 to 20% methacrylic acid, by total weight of the composition. If present, the composition comprises from 1 to 16%, preferably from 3 to 12%, methacrylic acid, by total weight of the composition. The composition may include, for example, 0 to 1%, alternatively 1 to 2%, alternatively 2 to 3%, alternatively 3 to 4%, alternatively 4 to 5%, alternatively 5 to 6%, alternatively 6 to 7%, alternatively 7 to 8%, alternatively 8 to 9%, alternatively 9 to 10%, alternatively 10 to 11%, alternatively 11 to 12%, alternatively 12 to 13%, alternatively 13 to 14%, alternatively 14 to 15%, alternatively 15 to 16%, alternatively 16 to 17%, alternatively 17 to 18%, alternatively 18 to 19%, alternatively 19 to 20%, of methacrylic acid, by total weight of the composition. Urethane (meth)acrylate oligomer

[0092] The composition may comprise at least one urethane (meth)acrylate oligomer.

[0093] The composition may comprise from 0 to 7% of at least one urethane (meth)acrylate oligomer, by total weight of the composition. If present, the composition comprises from 0.1 to 7%, preferably from 3 to 6%, of at least one urethane (meth)acrylate oligomer, by total weight of the composition. The composition may comprise, for example, from 0 to 1%, alternatively from 1 to 2%, alternatively from 2 to 3%, alternatively from 3 to 4%, alternatively from 4 to 5%, alternatively from 5 to 6%, alternatively from 6 to 7%, alternatively from 7 to 8%, alternatively from 8 to 9%, alternatively from 9 to 10%, of at least one urethane (meth)acrylate oligomer, by total weight of the composition.

[0094] The urethane (meth)acrylate oligomer can be chosen from aliphatic diacrylate methane oligomers, preferably the urethane (meth)acrylate oligomer is aliphatic urethane diacrylate.

[0095] The composition may further comprise at least one monofunctional reactive diluent.

[0096] The composition may comprise from 0 to 0.7% of at least one monofunctional reactive diluent, by total weight of the composition. If present, the composition comprises from 0.1 to 0.7%, preferably from 0.3 to 0.7%, of at least one monofunctional reactive diluent, by total weight of the composition.

[0097] The monofunctional reactive diluent may be 2-(2-ethoxy-ethoxy)ethyl acrylate. A mixture of a methane (meth)acrylate oligomer and a monofunctional reactive diluent, consisting of approximately 90% aliphatic urethane diacrylate and approximately 10% 2-(2-ethoxy-ethoxy)ethyl acrylate by total weight of the mixture, is commercially available under the Sartomer brand name CN966H90®. Viscosity

[0098] The composition may have a viscosity of 100 to 10,000 mPa.s, preferably of 500 to 5,000 mPa.s, preferably of 1,000 to 2,500 mPa.s. The viscosity can be measured according to standard NF EN 12092 "Adhesives - Determination of viscosity" using a Brookfield DVIII Ultra viscometer (mobile: SC4-27, rotation: 20 rpm, temperature: 25°C). Glass transition temperature

[0099] The composition comprises a glass transition temperature, preferably of at least 85°C, preferably of at least 90°C, preferably of at least 100°C.

[0100] In particular embodiments, the composition may comprise (alternatively may consist of), by total weight of the composition: - from 20 to 35%, preferably from 25 to 30%, of at least one block copolymer; - from 45 to 75%, preferably from 45 to 70%, preferably from 45 to 65%, of at least one (meth)acrylate monomer having a glass transition temperature of at least 85°C; - from 2 to 15%, preferably from 3 to 10%, preferably from 4 to 6%, - of at least one alkoxysilane (meth)acrylate monomer; - from 0.1 to 5%, preferably from 0.5 to 4%, preferably from 1 to 3%, of at least one photoinitiator; - from 0 to 5%, preferably from 0.1 to 5%, of at least one (meth)acrylate monomer having a glass transition temperature below 0°C; - from 0 to 20%, preferably from 1 to 16%, preferably from 3 to 12%, of methacrylic acid; - from 0 to 7%, preferably from 0.1 to 7%, preferably from 3 to 6%, of at least one urethane (meth)acrylate oligomer; and - from 0 to 0.7%, preferably from 0.1 to 0.7%, preferably from 0.3 to 0.7%, of at least one monofunctional reactive diluent.

[0101] In particular embodiments, the composition may comprise (alternatively may consist of): - at least one block copolymer; preferably at least one (meth)acrylic block copolymer; preferably a (meth)acrylic block copolymer having a triblock MBM structure; - at least one (meth)acrylate monomer having a glass transition temperature of at least 85°C; preferably a monomer selected from the group consisting of methyl methacrylate, tert-butyl methacrylate, phenyl methacrylate, isobornyl methacrylate, isobornyl acrylate, cyclohexyl methacrylate, 4-ter-butylcyclohexyl methacrylate, dihydrodicyclopentadienyl acrylate and mixtures thereof; preferably a monomer being methyl methacrylate; - at least one alkoxysilane (meth)acrylate monomer; preferably a monomer selected from the group consisting of the trikoxysilane (meth)acrylate monomers; preferably the trimethoxysilane (meth)acrylate monomers; preferably 3-(trimethoxysilyl)propyl acrylate, 3-(trimethoxysilyl)propyl methacrylate, trimethoxysilyl acrylate, trimethoxysilyl acrylate and mixtures thereof; preferably a monomer being trimethoxysilyl acrylate; - at least one photoinitiator; preferably a photoinitiator selected from the group consisting of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, triethylbenzoyl-diphenylphosphine oxide, thioxanthen-9-one, 4,4-bis(diethylamino)benzophenone, 9,10-phenanthrene quione, benzoyltrimethylgermane, dibenzoyldiethylgermane, bis-(4-methoxybenzoyl)diethylgermanium and mixtures thereof; preferably a photoinitiator being phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide; - optionally at least one (meth)acrylate monomer having a glass transition temperature below 0°C; preferably a monomer selected from the group consisting of butyl acrylate, ethyl acrylate, propyl acrylate, hexyl acrylate, octyl acrylate, dodecyl acrylate, isopropyl acrylate, isobutyl acrylate, isodecyl acrylate, 2-ethylhexyl acrylate, 2-propylheptyl acrylate, isodecyl methacrylate, dodecyl methacrylate, 2-hydroxyethyl acrylate and mixtures thereof; preferably a monomer being butyl acrylate; - optionally a methacrylic acid monomer; - optionally at least one urethane (meth)acrylate oligomer; preferably an oligomer selected from aliphatic diacrylate methane oligomers; preferably an oligomer being aliphatic urethane diacrylate; - optionally at least one monofunctional reactive diluent; preferably a diluent being 2-(2-ethoxy-ethoxy) ethyl acrylate. Single-component composition

[0102] The composition may be a single-component composition, that is to say a ready-to-use composition.

[0103] A single-component composition does not need to be prepared as at least two separate components that must be mixed just before use to prevent premature polymerization. This is because the single-component composition includes at least one photoinitiator, which allows polymerization to begin as soon as the composition is exposed to light, particularly ultraviolet (UV) radiation. To prevent premature or unwanted polymerization, the composition must not be exposed to light. Adhesive product

[0104] In a second aspect, the present invention comprises an adhesive product.

[0105] The adhesive product comprises the photopolymerizable adhesive composition as described above and an opaque container containing it. "Opaque container" means a container whose walls do not allow the passage of light capable of activating the photoinitiator, in particular visible light and ultraviolet radiation (below 600 nm).

[0106] The opaque container can be any container capable of holding the composition and preserving its properties, in particular its adhesive properties. The use of an opaque container prevents the composition from being exposed to light (in particular ultraviolet radiation) before use, i.e., during storage and transport, and thus avoids any premature or unwanted polymerization.

[0107] The container can be chosen, for example, from the group consisting of a bottle or a tube. Adhesive

[0108] In a third aspect, the present invention relates to an adhesive, in particular an adhesive obtained from the photopolymerizable adhesive composition as described above. By "adhesive" or "photopolymerized adhesive composition" is meant the adhesive layer obtained by applying the photopolymerizable adhesive composition, by photopolymerizing it, and optionally by shaping the adhesive thus obtained.

[0109] The adhesive is obtained by the process comprising the following steps: - application of the photopolymerizable adhesive composition as described above on at least one hood and / or an electronic or optoelectronic device; - photopolymerization of the applied composition to obtain a polymerized adhesive; and - optionally shaping of the polymerized adhesive.

[0110] The adhesive can take the form of a film.

[0111] The application of the composition can be carried out by a conventional application technique, for example the following techniques: slot-die coating, deep coating, inkjet printing, screen printing, spin coating, spray coating or with a rigid knife applicator (doctor blade).

[0112] Photopolymerization of the composition can be carried out by exposure to ultraviolet (UV) radiation and visible light, in particular by using a UV lamp emitting in a range that activates the photoinitiator without being absorbed by the encapsulating cap. A suitable UV lamp could be, for example, a UV LED system such as the Delolux® 03S. Photopolymerization can be carried out in 1 to 10 minutes.

[0113] The optional shaping of the adhesive can be implemented, for example, by a thermoforming technique.

[0114] The adhesive can have a thickness of 10 to 200 µm, preferably 10 to 100 µm, preferably 10 to 30 µm.

[0115] The adhesive has a number of advantages, particularly for use at a temperature of at least 70°C, preferably at least 85°C, for example when the electronic or optoelectronic device is a photovoltaic cell or when the device must meet temperature test standards (e.g. automotive applications).

[0116] The adhesive preferably has satisfactory adhesive properties, in particular to allow satisfactory cohesion between the electronic or optoelectronic device and the covers, even for flexible modules.

[0117] The adhesive preferably exhibits satisfactory optical properties, in particular satisfactory transparency, notably to allow the transmission of light waves to the electronic or optoelectronic device and / or to limit diffraction, particularly when the device is a photovoltaic cell. The adhesive can have a transmission transparency of 90% between 400 and 800 nm. The transparency can be measured by UV-visible transmission spectrometry.

[0118] The adhesive preferably exhibits satisfactory electrical properties, in particular satisfactory electrical insulation properties, notably to prevent any short circuit within the module. The electrical insulation properties can be measured according to ASTM D149.

[0119] The adhesive preferably exhibits satisfactory resistance, in particular to aging under ultraviolet radiation, to abrasion and / or to impacts.

[0120] The adhesive preferably exhibits satisfactory barrier properties, in particular barrier properties against water and oxygen (air). The barrier properties can be measured according to ASTM F1249 with a water vapor transmission rate of less than 5 gm².d⁻¹, preferably less than 2 gm².d⁻¹, for a thickness of 1 mm, at a temperature of 38°C and a relative humidity of 85%.

[0121] The adhesive preferably exhibits satisfactory elastic properties. The elastic properties, in particular flexibility, can be measured using a cylindrical mandrel bending tester, with the three- or four-point bending test method, or with tensile measurements. Electronic or optoelectronic module

[0122] In a fourth aspect, the present invention relates to a module, preferably a flexible module. The module corresponds to an encapsulated electronic or optoelectronic device.

[0123] The module can be obtained by superimposing and assembling a series of layers. The series of layers can comprise, in this order: - a first cover; - a first adhesive as described above or obtained from the photopolymerizable adhesive composition as described above; - an electronic or optoelectronic device; - a second adhesive as described above or obtained from the photopolymerizable adhesive composition as described above; and - a second cap.

[0124] The electronic or optoelectronic device may itself comprise a semiconductor layer deposited on a support substrate.

[0125] This series of layers may also include additional layers, in particular layers intercalated between a hood and an adhesive, for example an additional layer improving adhesion between the internal surface of a hood and a layer of adhesive composition, a surface treatment of the hood, etc.

[0126] In the module thus obtained, the electronic or optoelectronic device is preferably coated by the two adhesives, which overlap at their periphery to form a watertight seal. The coating of the electronic or optoelectronic device by the adhesives, and its encapsulation between the two covers, isolates it from its environment.

[0127] The module thus obtained exhibits satisfactory properties, making it possible to limit, or even prevent, both orthogonal permeation and lateral permeation, while preserving the flexibility properties of the electronic or optoelectronic device.

[0128] The module can have a total thickness of 50 to 500 pm, preferably of 50 to 300 pm, preferably of 50 to 150 pm.

[0129] The electronic or optoelectronic devices may be chosen from rigid devices, flexible devices or combinations thereof; preferably the devices are flexible devices; preferably the devices are chosen from organic light-emitting diodes, organic photovoltaic cells, organic transistors, organic transistors or organic sensors.

[0130] In a particular embodiment, the photovoltaic cells are perovskite-type devices. The so-called halogenated perovskite material may include in its crystalline structure a metal (for example, lead or tin), organic and inorganic cations (for example, cesium, formamidinium, and / or ammonium), and halide anions (for example, boron or iodine). Perovskite-type devices are particularly well-suited to photovoltaic applications. However, perovskite-type devices may exhibit long-term stability problems due to their sensitivity to the atmosphere, particularly to water vapor.

[0131] The hoods may be identical or different.

[0132] The hoods can be single-layer or multi-layer.

[0133] The hoods can be flexible or rigid, preferably flexible.

[0134] The module may have an orientation, for example in that it comprises a lower or rear cover (commonly referred to as the "backsheet") and an upper or front cover (commonly referred to as the "frontsheet"). The upper or front cover is preferably transparent and the lower or rear cover is preferably opaque.

[0135] Depending on the electronic or optoelectronic device used and the desired characteristics and properties of the module, the hoods may have specific properties.

[0136] A hood can be a polymer hood.

[0137] A hood can be an inorganic hood.

[0138] A polymer hood may include at least one fluorinated polymer layer obtained from at least one fluorinated polymer, for example poly(vinyl fluoride) (PVF), poly(vinylidene fluoride) (PVDF) and their mixture.

[0139] A polymer hood may include at least one polymer layer obtained from polyethylene terephthalate (PET) (or PET layer).

[0140] A polymer hood may include at least one polymer layer obtained from ethylene-vinyl acetate (EVA) (or EVA layer).

[0141] A single-layer cap may comprise one layer selected from a fluoropolymer layer, a PET layer, or an EVA layer. A multi-layer cap may comprise at least two layers, preferably three layers, selected from a fluoropolymer layer, a PET layer, an EVA layer, or combinations thereof. For example, a three-layer cap may be a fluoropolymer layer / PET layer / fluoropolymer layer cap or a fluoropolymer layer / PET layer / EVA layer cap.

[0142] The fluorinated polymer layer, the PET layer, the EVA layer and their combinations, and the single-layer or multi-layer caps obtained from them, are particularly suitable for use as a lower or rear cap.

[0143] A hood may include at least one layer of glass.

[0144] A hood may comprise at least one polymeric layer obtained from polymethyl methacrylate (PMMA) (or PMMA layer).

[0145] The glass layer or the PMMA layer is particularly suitable for use as a top or front cover.

[0146] A flexible hood, particularly suitable for encapsulating flexible electronic or optoelectronic devices, especially organic photovoltaic cells, for example perovskite-type devices, is commercially available under the name 3M Ultra-Barrier Solar Film by 3M®. This hood is a laminated multilayer hood comprising a PET film, an inorganic barrier layer, a PSA (pressure-sensitive adhesive) film, and a fluoropolymer film.

[0147] Method for obtaining the electronic or optoelectronic module

[0148] In a fifth aspect, the present invention relates to a method for obtaining the module as described above, the method comprising the following steps: - the provision of an electronic or optoelectronic device; - the supply of a photopolymerizable adhesive composition as described above; - the supply of a first hood; - the supply of a second hood; - the application of layers of adhesive photopolymerizable composition on the surface of the device and / or on respective internal surfaces of the first and second caps;

[0149] - the lamination of the device and the layers of photopolymerizable composition adhesive between the respective internal surfaces of the first and second caps; and - the photopolymerization of the layers of adhesive photopolymerizable composition.

[0150] The method may also include an irradiation step with ultraviolet-ozone radiation of the first hood and / or the second hood before the application step and / or the lamination step.

[0151] In a particular embodiment, the rigid modules are obtained by a vacuum lamination (rolling) technique at temperature (designated “sheet to sheet” in English).

[0152] In a particular embodiment, the flexible modules are obtained by a roll-to-roll technique, as described, for example, in the article by S. Razza et al. entitled "Research Update: Large-area deposition, coating, printing, and processing techniques for the upscaling of perovskite solar cell technology," APL Materials (2016) 4(9). This technique is particularly well-suited to flexible electronic or optoelectronic devices; preferably devices selected from organic light-emitting diodes, organic photovoltaic cells, organic transistors, or organic sensors; preferably perovskite-type devices. Applications and uses

[0153] In a sixth aspect, the present invention relates to the use of the adhesive photopolymerizable composition as described above, and of the adhesive as described above obtained from it, for the encapsulation of electronic or optoelectronic devices, in particular for the encapsulation of flexible electronic or optoelectronic devices, for example for the encapsulation of organic photovoltaic devices, in particular perovskite-type devices. EXAMPLES

[0154] The following examples illustrate the invention without limiting it. List of materials and equipment

[0155] Block copolymer: MBM triblock copolymer [polymethyl methacrylate-poly(styrene-co-butylacrylate)-polymethyl methacrylate block copolymer] (abbreviation: MBM)

[0156] (Meth)acrylate monomers having a glass transition temperature of at least 85°C: methyl methacrylate (abbreviation: MAM)

[0157] Alkoxysilane (meth)acrylate monomers: trimethoxysilane acrylate (Momentive® product Silquest® A174) (abbreviation: A174)

[0158] Photoinitiators: phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (product Irgacure® 819 from Ciba® Specialty Chemicals) (abbreviation: 1819), also available from Sigma-Aldrich

[0159] (Meth)acrylate monomers having a glass transition temperature below 0°C: butyl acrylate (abbreviation: ABu)

[0160] Methacrylic acid (abbreviation: AMA)

[0161] Methane (meth)acrylate oligomers: aliphatic methane diacrylate in 10% of 2-(2-ethoxy-ethoxy) ethyl acrylate (Sartomer product CN966H90®) (abbreviation: CN966)

[0162] Commercial composition: delo® katiobond® lp655 from Delo

[0163] Light source: Delolux® 03S UV LED system Modules to test

[0164] The modules to be tested are commonly referred to as test specimens.

[0165] PK layer: perovskite layer of formula Cso>o5FAoj95Pb(Ioj88Broji2)3 with a surface area of ​​4x4 cm (16 cm2)

[0166] Glass layer: layer with a surface area of ​​5x5 cm (25 cm2)

[0167] ITO layer: tin-doped indium oxide layer

[0168] SnO2 layer: tin dioxide layer

[0169] The glass, ITO and / or SnO2 layers form the supporting substrate as such.

[0170] Multilayer module 1: glass / ITO / SnO2 / PK

[0171] Multilayer module 2: glass / ITO / PK / ITO

[0172] The SnO2 and / or PK layers are deposited by the centrifugal coating technique. The top ITO layer (module 2) is deposited by physical vapor deposition.

[0173] The perovskite layers are deposited on the support substrate, with a 5 mm overlap between the edge of the substrate and the perovskite layer.

[0174] The modules are individually encapsulated between two glass caps having a thickness of 1.2 mm by means of the photopolymerizable compositions to be tested.

[0175] Test methods: The thermal properties and gas barriers of the tested modules were analyzed using a differential scanning calorimeter (DSC). Measurements were performed over three heating-cooling cycles from -80 to 200°C at a rate of 10°C per minute. The glass transition temperature was measured on the third heating cycle using the mid-height tangent method calculated between 40° and 140°C.

[0176] The degradation rate (cm² / h) is determined with respect to the degradation of a perovskite layer. The degradation of the tested modules was assessed using the following method: the specimen as described above is placed in a climatic chamber at a temperature of 85°C and a relative humidity of 85%, in accordance with the climatic test conditions for photovoltaic modules reported in the IEC 61615 standard method, in order to determine an algorithmic parameter for the degradation rate (cm² / h). See the article by E. Booker et al. entitled “Perovskite Test: A high throughput method to screen ambient encapsulation conditions, Energy Technology (2020) 8(12). Photographs of the test specimens are taken regularly, for example approximately every 48 hours, to assess the aging of the perovskite layers. The remaining surface area of ​​the perovskite layers (thickness) is determined in order to calculate the degradation rate of these layers (cm² / h) from a linear regression of points between 12 cm² and 2 cm². Areas with a thickness of 180 nm or less are considered degraded (black areas by algorithmic analysis), and areas with a thickness greater than 180 nm are considered intact (gray areas by algorithmic analysis). Photopolymerizable adhesive compositions

[0177] The following adhesive photopolymerizable compositions were prepared (see Table 1, proportions expressed as mass percentage relative to the total weight of the adhesive photopolymerizable composition):

[0178] [Tables] MBM MAM A174 ABu AMA CN966 1819 Exl 29.21 53.55 4.87 0 4.87 4.87 2.63 Ex2 20.45 62.31 4.87 0 4.87 4.87 2.63 Ex3 34.08 48.68 4.87 0 4.87 4.87 2.63 Ex4 29.21 53.55 4.87 0 9.74 0 2.63 Ex5 25.32 53.55 4.87 3.89 4.87 4.87 2.63 CExA 29.21 37.48 4.87 16.07 4.87 4.87 2.63 CExB 29.21 44.98 4.87 8.57 4.87 4.87 2.63

[0179] Compositions CExA and CExB are comparative compositions. Test 1

[0180] In a first test, the degradation rate of multilayer modules 1 obtained with composition Exl (invention) and compositions CExA and CExB (comparatives) is tested. Two series of tests are carried out with each composition.

[0181] These compositions differ in particular in the proportion of (meth)acrylate monomers having a glass transition temperature below 0°C (in this case butyl acrylate), considering that they comprise an identical total proportion (53.55%) of (meth)acrylate monomers, i.e. the mixture of monomers having a glass transition temperature of at least 85°C and (meth)acrylate monomers having a glass transition temperature below 0°C.

[0182] The glass transition temperatures of the compositions used are as follows: 62.6°C for composition CExA, 75.7°C for composition CExB and 94.14°C for composition Exl. Composition Ex5 (invention) has a glass transition temperature of 86.2°C.

[0183] The modules tested are photographed at regular intervals. The photographs are taken at 0, 159h, 280h, 351h, 447h, 521h, 624h, 737h, 852h, 948h and 1091h, as illustrated in [Fig.1] (the first lines correspond to the photographs and the second lines correspond to the images after computer analysis).

[0184] The degradation rate is correlated with the decrease in perovskite surface area over time, compared to undegraded perovskite surfaces (time = Oh), which allows comparison of the influence of different compositions on lateral permeation.

[0185] As illustrated in [Fig.2], contrary to composition Exl, this test demonstrates that the comparative compositions, comprising a high proportion of (meth)acrylate monomers having a glass transition temperature below 0°C, exhibit an insufficient glass transition temperature and a high degradation rate, which corresponds to a high lateral permeation rate.

[0186] Furthermore, the modules tested according to the invention exhibit a water vapor transmission rate of 2 g.mm.M 2.d', according to the method described in the article by A. Kovrov et al. entitled "Novel acrylic monomers for organic photovoltaics encapsulation", Solar Energy Materials & Solar Cells (2020) 110210. Test 2

[0187] In a second test, the degradation rate of multilayer modules 2 obtained with compositions Ex 1-3 (invention) is tested. Two series of tests are carried out with each composition.

[0188] These compositions differ in particular in the proportion of block copolymer.

[0189] The modules tested are photographed at regular intervals. The photographs are taken at 0, 265h, 505h, 771h, 1002h, as illustrated in [Fig.3] (each line corresponds to the photographs).

[0190] This test demonstrates that there is no significant difference between the degradation rates of the three types of modules tested, confirming that these proportions of block copolymers do not negatively affect the gas barrier properties of the adhesive compositions or their glass transition temperature, while maintaining satisfactory elastic (flexibility) properties. Test 3

[0191] In a third test, the photoaging under continuous illumination under 1 sun (sun - AM 1.5 spectrum) of adhesive layers obtained from the Exl composition (invention) with a thickness of approximately 200 pm is tested, by comparison to layers obtained with a commercially available composition (delo® katiobond® lp655) and having a thickness of 200 pm.

[0192] As illustrated in the graph according to [Fig. 4], the photoaging of the layers, and their eventual yellowing, is measured between 0 and 1600 h. The empty circles (white) correspond to the data relating to the commercial composition at 1600 h, the filled circles (black) correspond to the data relating to the commercial composition at 0 h, the empty triangles (white) correspond to the data relating to the Exl composition at 1600 h, the filled triangles (black) correspond to the data relating to the Exl composition at 0 h

[0193] This test demonstrates a significant yellowing of the layer obtained with a commercially available composition, which necessarily leads to a decrease in the light transmission range, unlike the adhesive layers obtained from the Exl composition (invention)

Claims

Demands

1. A light-cured adhesive composition comprising, by total weight of the light-cured adhesive composition: 20 to 35% of at least one block copolymer; 45 to 75% of at least one (meth)acrylate monomer having a glass transition temperature (Tg) of at least 85°C; 2 to 15% of at least one alkoxysilane (meth)acrylate monomer; and 0.1 to 5% of at least one photoinitiator; a light-cured adhesive composition wherein the block copolymer is selected from the group consisting of block copolymers comprising at least one M block and at least one B block; said M block designating a polymer block comprising at least 50% by weight of methyl methacrylate; and block B designates an elastomeric polymer block incompatible with block M, and whose glass transition temperature (Tg) is less than 20°C.

2. Adhesive photopolymerizable composition, according to claim 1, wherein the (meth)acrylate monomer having a glass transition temperature of at least 85°C is selected from the group consisting of methyl methacrylate, tert-butyl methacrylate, phenyl methacrylate, isopropyl methacrylate, isobomyl methacrylate, isobornyl acrylate, cyclohexyl methacrylate, 4-ter-butylcyclohexyl methacrylate, dihydrodicyclopentadienyl acrylate and mixtures thereof.

3. Adhesive photopolymerizable composition, according to any one of the preceding claims, wherein the alkoxysilane (meth)acrylate monomer is selected from the group consisting of the trialkoxysilane (meth)acrylate monomers.

4. Adhesive photopolymerizable composition, according to any one of the preceding claims, further comprising at least one (meth)acrylate monomer having a glass transition temperature below 0°C, a methacrylic acid monomer, at least one (meth)acrylate urethane oligomer, at least one monofunctional reactive diluent and mixtures thereof.

5. Adhesive photopolymerizable composition, according to claim 4, wherein the (meth)acrylate monomer having a glass transition temperature below 0°C, if present, is selected from the group consisting of butyl acrylate, ethyl acrylate, propyl acrylate, hexyl acrylate, octyl acrylate, dodecyl acrylate, isopropyl acrylate, isobutyl acrylate, isodecyl acrylate, 2-ethylhexyl acrylate, 2-propylheptyl acrylate, isodecyl methacrylate, dodecyl methacrylate, 2-hydroxyethyl acrylate and mixtures thereof.

6. Adhesive product comprising the photopolymerizable adhesive composition according to any one of the preceding claims and an opaque container containing it.

7. Adhesive obtained by the process comprising the following steps: application of a photopolymerizable adhesive composition according to any one of claims 1 to 5 on at least one cover and / or an electronic or optoelectronic device; photopolymerization of the applied photopolymerizable adhesive composition to obtain a polymerized adhesive; and optionally shaping of the polymerized adhesive.

8. Electronic or optoelectronic module comprising the assembly of a series of layers including, in this order: a first cover; a first adhesive according to claim 7 or obtained from the adhesive photopolymerizable composition according to any one of claims 1 to 5; a flexible electronic or optoelectronic device; a second adhesive according to claim 7 or obtained from the adhesive photopolymerizable composition according to any one of claims 1 to 5; and a second cover.

9. Electronic or optoelectronic module, according to claim 8, wherein the flexible electronic or optoelectronic device is selected from organic light-emitting diodes, organic photovoltaic cells, organic transistors, or organic sensors.

10. Electronic or optoelectronic module, according to any one of claims 8 and 9, wherein the flexible electronic or optoelectronic device is a perovskite-type device.

11. A method for obtaining the module according to any one of claims 8 to 10, the method comprising the following steps: providing an electronic or optoelectronic device; providing an adhesive photopolymerizable composition according to any one of claims 1 to 5; providing a first cover; providing a second cover; applying layers of adhesive photopolymerizable composition to the surface of the device and / or to respective internal surfaces of the first and second covers; laminating the device and the layers of adhesive photopolymerizable composition between the respective internal surfaces of the first and second covers; and photopolymerizing the layers of adhesive photopolymerizable composition.

12. Use of the photopolymerizable adhesive composition according to any one of claims 1 to 5, or of the adhesive according to claim 7, for the encapsulation of flexible electronic or optoelectronic devices.

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