Photopolymerizable adhesive composition for encapsulation of electronic or optoelectronic devices - Patent Application 20070123633

Abstract

The present invention relates to photopolymerizable adhesive compositions used to encapsulate electronic and optoelectronic devices, particularly flexible electronic and optoelectronic devices such as photovoltaic cells, to protect them from gas and moisture penetration.

Description

[Technical field]

[0001] The present invention relates to photopolymerizable adhesive compositions used to encapsulate electronic and optoelectronic devices, particularly flexible electronic and optoelectronic devices such as organic photovoltaic cells, to protect them from the ingress of gases and moisture. [Background technology]

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

[0003] Rigid electronic and optoelectronic devices exist in a variety of types depending on the intended application, such as displays (e.g., OLEDs and QLEDs), photovoltaics (e.g., silicon semiconductors, CIGS cells, CdTe cells, organic semiconductors, perovskite semiconductors), or sensors.

[0004] Flexible electronic and optoelectronic devices may be defined with the same application examples, but are directed to semiconductor technologies that are compatible with the use of flexible substrates, such as organic light emitting diodes (OLEDs), organic photovoltaics (OPVs), amorphous silicon cells (a-Si), CIGS cells, perovskite semiconductors, organic field effect transistors (OFETs), or organic sensors using organic semiconductors.

[0005] Electronic and optoelectronic devices are devices that are sensitive to several factors, such as light, heat, oxygen (air), moisture, pressure, and shock. Therefore, to ensure optimal effectiveness and yield, and to obtain a satisfactory durability, these devices must be protected and isolated from their environment. This protection must be even more effective if the materials of construction are sensitive to the atmosphere, especially water and oxygen. This is especially true when using organic semiconductors, such as perovskite or CIGS semiconductors.

[0006] Various encapsulation techniques have been developed. These usually involve coating the device with an adhesive composition to obtain a coated device and then laminating the coated device between two barrier layers to obtain an encapsulated device. The choice of adhesive composition and barrier layer depends on the device to be encapsulated. Furthermore, depending on the composition and barrier layer used, the resulting electronic or optoelectronic module will have properties in terms of weight, thickness, transparency / opacity, rigidity / flexibility, permeability / hermeticity to gases and liquids, impact strength / durability / aging resistance, among others.

[0007] Due to the layered arrangement, two types of penetration are observed: orthogonal penetration at the outer surfaces of the barrier layers sandwiching the coated device, and lateral penetration at the free edges of the adhesive between the coating material and the inner surfaces of the two barrier layers.

[0008] The protection of the device against lateral penetration is ensured in particular by adhesives or coating materials, the effectiveness of which depends on various factors, such as in particular their chemical composition, the procedure of application, their thickness (proportional to the surface exchanged with the environment), their interface with the barrier layer, their resistance to operational stresses, etc. The properties of the adhesive must therefore be optimized to minimize or even eliminate lateral penetration, thus ensuring optimal effectiveness and yield and obtaining a satisfactory durability.

[0009] Flexible photovoltaics (e.g. organic, perovskite, CIGS, CdTe cells) are a particularly interesting alternative to rigid silicon-based photovoltaics, in that they can be produced in continuous (roll-to-roll) processes at high production rates and are suitable for applications where flexibility, conformability or light weight is required. They also have the advantage that they are less prone to breakage and damage (due to the use of flexible barrier layers).

[0010] Flexible photovoltaic cells may for example be obtained by low-temperature printing of thin active layers (organic or perovskite materials with semiconducting properties) deposited on a supporting flexible polymer substrate.

[0011] Encapsulation of flexible electronic or optoelectronic devices is achieved, for example, by a barrier layer that is substantially impermeable to gases, particularly water vapor and oxygen, but which must be at least as flexible as the device it protects so as not to be a limiting factor in bending the device, or must have a controlled flexibility, for example if the encapsulation is used intentionally to limit the radius of curvature of the device to prevent damage to the device.

[0012] Therefore, there is a real need to provide an adhesive composition with which electronic or optoelectronic modules can be obtained with satisfactory properties, in particular satisfactory adhesion, optical, thermal, electrical, gas barrier, elasticity and strength properties. There is also a need to provide an adhesive composition suitable for encapsulating flexible electronic or optoelectronic devices. Furthermore, there is a need to provide an adhesive composition with which electronic or optoelectronic modules can be obtained with time-limited photoaging (e.g. yellowing). There is also a need to provide an adhesive composition with which electronic or optoelectronic modules can be obtained with time-limited lateral penetration of gas and water. There is also a need to provide an adhesive composition with which electronic or optoelectronic modules can be obtained with satisfactory durability, ensuring optimal effectiveness and yield. Summary of the Invention

[0013] In a first aspect, the present invention relates to a photopolymerizable adhesive composition, the photopolymerizable adhesive composition comprising, based on the total weight of the photopolymerizable adhesive composition: - 20 to 35% by weight of at least one block copolymer, preferably a (meth)acrylic block copolymer, - 45 to 75% by weight of at least one (meth)acrylate monomer having a glass transition temperature (Tg) of at least 85°C; - 2 to 15 wt. % of at least one alkoxysilane (meth)acrylate monomer; - 0.1 to 5% by weight of at least one photoinitiator.

[0014] In some embodiments, the block copolymer is selected from the group consisting of block copolymers comprising at least one block M and at least one block B, wherein the block M represents a block polymer comprising at least 50% by weight of methyl methacrylate, and the block B represents an elastomeric block polymer that is incompatible with the block M and has a glass transition temperature below 20° C.

[0015] In some 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, isobornyl acrylate, cyclohexyl methacrylate, 4-tert-butylcyclohexyl methacrylate, dihydrodicyclopentadienyl acrylate, and mixtures thereof.

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

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

[0018] In some embodiments, the (meth)acrylate monomer having a glass transition temperature less than 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] In some embodiments, the photopolymerizable adhesive composition is advantageously a one-component composition.

[0020] In some embodiments, the photopolymerizable adhesive composition has a glass transition temperature of at least 85°C, preferably at least 90°C, and more preferably at least 100°C.

[0021] In a second aspect, the present invention relates to an adhesive product comprising a photopolymerizable adhesive composition as described above and an opaque container containing the same.

[0022] In a third aspect, the present invention relates to an adhesive comprising: - applying a photopolymerizable adhesive composition as described above to at least one barrier layer and / or electronic or optoelectronic device; - photopolymerizing the applied photopolymerizable adhesive composition to obtain a polymerized adhesive; - optionally, shaping said polymerized adhesive.

[0023] In a fourth aspect, the present invention relates to an electronic or optoelectronic module, comprising: a first barrier layer, a first adhesive as described above or obtained from a photopolymerizable adhesive composition as described above, - flexible electronic or optoelectronic devices, a second adhesive as defined above or obtained from a polymerizable adhesive composition as defined above, and - a second barrier layer.

[0024] In some embodiments, the flexible electronic or optoelectronic device is selected from an organic light emitting diode, an organic photovoltaic cell, an organic transistor, or an organic sensor.

[0025] In some embodiments, the flexible electronic or optoelectronic device is a perovskite-based device.

[0026] In a fifth aspect, the present invention relates to a method for obtaining a module as described above, comprising the steps of: - providing an electronic or optoelectronic device; - providing a photopolymerizable adhesive composition as described above; - providing a first barrier layer; - providing a second barrier layer; - applying a layer of a photopolymerizable adhesive composition to a surface of the device and / or to the inner surface of each of the first and second barrier layers; - laminating said device and a layer of a photopolymerizable adhesive composition between the inner surfaces of said first and second barrier layers, respectively; - photopolymerizing the layer of photopolymerizable adhesive composition.

[0027] In a sixth aspect, the present invention relates to the use of a photopolymerizable adhesive composition as described above or an adhesive as described above for the encapsulation of flexible electronic or optoelectronic devices.

[0028] The inventors have surprisingly demonstrated that the photopolymerizable adhesive composition of the present invention exhibits fully satisfactory and even excellent properties, especially adhesion, optical properties, thermal properties, electrical properties, barrier properties, elasticity and strength properties, after application and photopolymerization.

[0029] Furthermore, the present invention has one or preferably several of the following advantages:

[0030] To obtain electronic or optoelectronic modules having satisfactory properties, in particular satisfactory adhesion, thermal, optical, electrical, gas barrier, elastic and strength properties.

[0031] - A satisfactory encapsulation of flexible electronic or optoelectronic devices is possible.

[0032] - To obtain electronic or optoelectronic modules with time-limited photoaging (eg yellowing).

[0033] To obtain an electronic or optoelectronic module with time-limited lateral penetration of gas and water.

[0034] To obtain an electronic or optoelectronic module that guarantees optimal efficiency and yield and has a satisfactory durability. [Brief description of the drawings]

[0035] [Figure 1] 1 shows corresponding photographs and images obtained after computer analysis of the module tested in test 1. [Diagram 2] 1 is a graph showing the degradation rate of modules tested in Test 1. [Diagram 3] 4 shows a photograph of the module tested in test 2. [Figure 4] 13 is a graph showing the transmittance as a function of wavelength (nm) for the modules tested in Test 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] The present invention will be described in more detail below, but the present invention is not limited to these descriptions.

[0037] "Flexible" or "supple" refers to the ability of a material to be easily bent, folded or folded, especially due to its inherent properties and / or thin thickness.

[0038] "Flexible electronic or optoelectronic device" (and module resulting therefrom) means a device (module) that retains its electronic conducting or semiconducting properties even when bent through a very small radius of curvature, without risk of buckling or delamination of the electronic components.

[0039] By "adhesive" is meant the matrix / structure formed around an electronic or optoelectronic device by the photopolymerizable adhesive composition. As used herein, the terms "adhesive" and "encapsulant" are used interchangeably.

[0040] "Module" means an assembly of electronic or optoelectronic devices coated with the polymerized adhesive composition and interposed between two barrier layers.

[0041] "Barrier layer" refers to an element that sandwiches a coated electronic or optoelectronic device in a laminate, which may be referred to interchangeably herein as a "substrate," "film," or "sheet."

[0042] "Photopolymerizable composition" or "photocrosslinkable composition" means a composition in which initiation of polymerization can be induced by exposure to electromagnetic radiation, especially ultraviolet (UV) radiation.

[0043] By "photopolymerizable adhesive composition" is meant a composition that develops adhesive properties upon exposure to electromagnetic radiation, particularly ultraviolet (UV) radiation, to initiate polymerization.

[0044] "Monomer" means a molecule capable of polymerization. When the term "monomer" is used to indicate a building block of a polymer, it means a unit (or residue) derived from a monomer (or monomer unit) (by polymerization with at least one other monomer).

[0045] "Polymerization" means the process of converting a single type of monomer or a mixture of different types of monomers into a polymer.

[0046] By "polymer" is meant a copolymer or a homopolymer.

[0047] "Homopolymer" means a polymer containing multiple identical monomeric units grouped together.

[0048] "Copolymer" means a polymer that groups at least two different types of monomer units (called comonomers).

[0049] The term "oligomer" refers to a small-sized polymer compound obtained by polymerizing 2 to 30 monomers (containing 2 to 30 monomer units), that is, a polymer compound having a degree of polymerization of 2 to 30.

[0050] "Block copolymer" refers to a polymer in which each of the different polymer species contains one or more uninterrupted sequences, which sequences are chemically distinct from each other and are linked to each other by covalent bonds. These polymer sequences are also called block polymers.

[0051] "(Meth)acrylic" (or "(meth)acrylate") refers to any type of acrylic and / or methacrylic (or acrylate and / or methacrylate) compound, polymer, monomer, or oligomer. For example, (meth)acrylic acid refers to acrylic acid or methacrylic acid, and isobornyl (meth)acrylate refers to isobornyl acrylate or isobornyl methacrylate.

[0052] "Polymerization" refers to a chemical process by which molecules can bond with each other to form three-dimensional networks.

[0053] "Initiator" means a chemical species that reacts with a monomer to form an intermediate compound that can combine with multiple other monomers to form a polymer, or that reacts with a polymer to start the molecular interconnection process called polymerization.

[0054] "Tg" means glass transition temperature. The glass transition temperature can be measured using differential scanning calorimetry (DSC), for example the half-tangent method, which measures between two inflection points on the third heating cycle from 40 to 140°C.

[0055] By "ambient temperature" is meant a temperature of about 20°C.

[0056] By "substantially free" it is meant that the composition contains less than 1% by weight, preferably less than 0.1% by weight, more preferably less than 0.01% by weight, and most preferably about 0% by weight of the compound, based on the total weight of the composition.

[0057] <Photopolymerizable adhesive composition> In a first aspect, the present invention relates to a photopolymerizable adhesive composition.

[0058] (Block Copolymer) The composition comprises at least one block copolymer, preferably at least one (meth)acrylic block copolymer.

[0059] The composition may comprise 20-35% by weight, preferably 25-30% by weight, of at least one block copolymer, relative to the total weight of the composition. For example, the composition may comprise 20-21% by weight, or 21-22% by weight, or 22-23% by weight, or 23-24% by weight, or 24-25% by weight, or 25-26% by weight, or 26-27% by weight, or 27-28% by weight, or 28-29% by weight, or 29-30% by weight, or 30-31% by weight, or 31-32% by weight, or 32-33% by weight, or 33-34% by weight, or 34-35% by weight, of at least one block copolymer, relative to the total weight of the composition.

[0060] By "(meth)acrylic block copolymer" is meant a (meth)acrylic block copolymer comprising 10% by weight or less (e.g., 0.1 to 10% by weight), preferably 5% by weight or less (e.g., 0.1 to 5% by weight) of at least one non-(meth)acrylic monomer, based on the total weight of the copolymer. The non-(meth)acrylic monomer may be selected from the group consisting of butadiene, isoprene, styrene, vinylnaphthalene, cyclosiloxane monomers, vinylpyridine, and derivatives thereof (e.g., α-methylstyrene or tert-butylstyrene).

[0061] The block copolymer may be selected from block copolymers comprising at least one block M and at least one block B, in particular block copolymers having a diblock structure BM (or BM diblock copolymer) or a triblock structure MBM (or MBM triblock copolymer), in which each block is linked to the other block by a covalent bond or by an intermediate molecule which is linked to one block by a covalent bond and to the other block by a covalent bond. The block copolymer is preferably an MBM triblock copolymer.

[0062] Block M denotes a block polymer comprising at least 50% by weight of methyl methacrylate. Block M may represent a homopolymer block of poly(methyl methacrylate) (PMMA-100% by weight of methyl methacrylate) or a block copolymer comprising at least 50% by weight of methyl methacrylate and up to 50% by weight of another monomer different from methyl methacrylate, relative to the total weight of block M.

[0063] Block B represents an elastomeric block polymer that is incompatible with block M and has a glass transition temperature (Tg) below ambient temperature, preferably below 0°C, more preferably below -20°C.

[0064] In the BM diblock copolymer, the block M may be composed of the monomer methyl methacrylate. Alternatively, the block M may comprise, relative to the total weight of the block M, at least 50% by weight (e.g. 50 to 99.9% by weight), preferably at least 75% by weight (e.g. 75 to 99.9% by weight), of methyl methacrylate and no more than 50% by weight (e.g. 0.1 to 25% by weight), preferably no more than 25% by weight (e.g. 0.1 to 25% by weight), of at least one other monomer different from methyl methacrylate.

[0065] The other monomer different from methyl methacrylate in the block M may be another (meth)acrylic monomer or a non-(meth)acrylic monomer.

[0066] The non-(meth)acrylic monomers may be selected from the group consisting of butadiene, isoprene, styrene, vinylnaphthalene, cyclosiloxane monomers, vinylpyridine, and derivatives thereof (eg, α-methylstyrene or tert-butylstyrene).

[0067] Other (meth)acrylic monomers 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, amides derived from (meth)acrylic acid (for example, N,N-dimethylacrylamide), 2-methoxyethyl (meth)acrylate, 2-aminoethyl (meth)acrylate, polyethylene glycol (PEG) (meth)acrylates with a molar mass of the polyethylene glycol (PEG) group between 400 and 10000 g / mol, and mixtures thereof.

[0068] The elastomeric block B may be composed of an alkyl (meth)acrylate monomer, or may contain at least 95% by weight (e.g., 95 to 99.9% by weight) of an alkyl (meth)acrylate and 5% by weight or less (e.g., 0.1 to 5% by weight) of another monomer different from the alkyl (meth)acrylate, based on the total weight of the block B.

[0069] The alkyl (meth)acrylate may be selected 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.

[0070] The other monomer different from the alkyl (meth)acrylate may be selected from the group consisting of butadiene, isoprene, styrene, vinylnaphthalene, cyclosiloxane monomers, vinylpyridine, and derivatives thereof (eg, α-methylstyrene or tert-butylstyrene).

[0071] The BM diblock copolymer may have a number average molecular weight of 10,000 to 500,000 g / mol, preferably 20,000 to 200,000 g / mol.

[0072] The BM diblock copolymer may have a weight fraction of M block (based on the total weight of the copolymer) of 5 to 95% by weight, preferably 15 to 85% by weight, and a weight fraction of B block of 5 to 95% by weight, preferably 15 to 85% by weight.

[0073] In the case of the MBM triblock copolymer, the two M blocks are composed of the same monomers (or comonomers) as the block M of the BM diblock copolymer as described above. These two blocks M may be the same or different. For example, these two blocks M may have different molar masses but be composed of the same monomers.

[0074] Block B is composed of the same monomers (or comonomers) as block B of the BM diblock copolymer as described above.

[0075] The MBM triblock copolymers may have a number average molar mass of from 10,000 g / mol to 500,000 g / mol, preferably from 20,000 g / mol to 200,000 g / mol.

[0076] The MBM triblock copolymer may have a weight fraction of block M (based on the total weight of the copolymer) of 10-80%, preferably 15-70%, more preferably 40-60%, and a weight fraction of block B of 20-90%, preferably 30-85%, more preferably 40-60%. An example of an MBM triblock copolymer is a polymethyl methacrylate-poly(styrene-co-butyl acrylate)-polymethyl methacrylate block copolymer.

[0077] The block copolymers may be prepared by controlled radical polymerization (CRP), for example according to the methods described in PCT applications WO 96 / 24620A and WO 00 / 71501A1, or by anionic polymerization.

[0078] At least one of the blocks M and B may be functionalized with one or more functional groups selected from the group consisting of acid, amine, amide, epoxy, thiol functional groups, quaternary ammonium groups, chlorinated groups, and fluorinated groups.

[0079] The block copolymers are commercially available under the trade name Nanostrength® Arkema.

[0080] ((Meth)acrylate Monomer) The composition comprises at least one (meth)acrylate monomer having a glass transition temperature (Tg) of at least 85°C.

[0081] The composition may comprise 45-75 wt%, preferably 45-70 wt%, more preferably 45-65 wt%, based on the total weight of the composition, of at least one (meth)acrylate monomer having a glass transition temperature of at least 85° C. For example, the composition may comprise 45-46 wt%, or 46-47 wt%, or 47-48 wt%, or 48-49 wt%, or 49-50 wt%, or 50-51 wt%, or 51-52 wt%, or 52-53 wt%, or 53-54 wt%, or 54-55 wt%, or 55-56 wt%, or 56-57 wt%, or 57-58 wt%, or 58-59 wt%, or 59-60 wt%, or 60-61 wt%, or 61 wt%, based on the total weight of the composition. % or 62 to 63% by weight, or 63 to 64% by weight, or 64 to 65% by weight, or 65 to 66% by weight, or 66 to 67% by weight, or 67 to 68% by weight, or 68 to 69% by weight, or 69 to 70% by weight, or 70 to 71% by weight, or 71 to 72% by weight, or 72 to 73% by weight, or 73 to 74% by weight, or 74 to 75% by weight of at least one (meth)acrylate monomer having a glass transition temperature of at least 85° C.

[0082] The (meth)acrylate monomer having a glass transition temperature of at least 85° C. may be 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, the (meth)acrylate monomer having a glass transition temperature of at least 85° C. is methyl methacrylate.

[0083] (Alkoxysilane (meth)acrylate monomer) The composition includes at least one alkoxysilane (meth)acrylate monomer.

[0084] The composition may comprise 2-15 wt%, preferably 3-10 wt%, more preferably 4-6 wt% of at least one alkoxysilane (meth)acrylate monomer, based on the total weight of the composition. For example, the composition may comprise 2-3 wt%, or 3-4 wt%, or 4-5 wt%, or 5-6 wt%, or 6-7 wt%, or 7-8 wt%, or 8-9 wt%, or 9-10 wt%, or 10-11 wt%, or 11-12 wt%, or 12-13 wt%, or 13-14 wt%, or 14-15 wt% of at least one alkoxysilane (meth)acrylate, based on the total weight of the composition.

[0085] The alkoxysilane (meth)acrylate monomer, including alkylalkoxysilane (meth)acrylate, may be selected from the group consisting of trialkoxysilane (meth)acrylate monomer, preferably trimethoxysilane (meth)acrylate monomer, preferably the alkoxysilane (meth)acrylate monomer may be 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.

[0086] Trimethoxysilane acrylate is sold by Momentive® under the trade name Silquest® A174.

[0087] (Photoinitiator) The composition comprises at least one photoinitiator. Any compound capable of initiating the photopolymerization of the adhesive composition may be used, in particular any compound capable of initiating the radical polymerization of monomers and / or urethane (meth)acrylate oligomers by ultraviolet (UV) or visible light to obtain an adhesive.

[0088] The composition may comprise 0.1-5 wt%, preferably 0.5-4 wt%, more preferably 1-3 wt% of at least one photoinitiator, based on the total weight of the composition. For example, the composition may comprise 0.1-1 wt%, or 1-2 wt%, or 2-3 wt%, or 3-4 wt%, or 4-5 wt% of at least one photoinitiator, based on the total weight of the composition.

[0089] 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-phenanthrenequinone, benzoyltrimethylgermane, dibenzoyldiethylgermane, bis-(4-methoxybenzoyl)diethylgermanium, and mixtures thereof, preferably phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide. For example, the mixture may include benzophenone, α-hydroxyketone, and triethylbenzoyl-diphenylphosphine oxide. Another mixture may include, for example, benzoyltrimethylgermane, dibenzoyldiethylgermane, and bis-(4-methoxybenzoyl)diethylgermanium.

[0090] Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide is sold by Ciba® Specialty Chemicals under the trade name Irgacure® 819. A mixture containing benzophenone, α-hydroxyketone and triethylbenzoyl-diphenylphosphine oxide is sold by Lehvoss under the trade name Esacure® KTO46.

[0091] (Other (meth)acrylate monomers) The composition may comprise at least one (meth)acrylate monomer having a glass transition temperature (Tg) less than 0° C. In this embodiment, the composition may comprise a mixture of (meth)acrylate monomers having a glass transition temperature of at least 85° C. and (meth)acrylate monomers having a glass transition temperature less than 0° C.

[0092] The composition may comprise 0-5 wt%, based on the total weight of the composition, of at least one (meth)acrylate monomer having a glass transition temperature below 0° C. If included, the composition may comprise 0.1-5 wt% of at least one (meth)acrylate monomer having a glass transition temperature below 0° C. For example, the composition may comprise 0-1 wt% (0.1-1 wt%), or 1-2 wt%, or 2-3 wt%, or 3-4 wt%, or 4-5 wt%, based on the total weight of the composition, of at least one (meth)acrylate monomer having a glass transition temperature below 0° C.

[0093] The (meth)acrylate monomer having a glass transition temperature of less than 0° C. may be 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 butyl acrylate.

[0094] Alternatively, the composition may be substantially free of (meth)acrylate monomers having a glass transition temperature (Tg) below 0°C.

[0095] (Methacrylic acid) The composition may include a methacrylic acid monomer.

[0096] The composition may contain 0-20% by weight of methacrylic acid, based on the total weight of the composition. When present, the composition contains 1-16% by weight, preferably 3-12% by weight, of methacrylic acid, based on the total weight of the composition. For example, the composition may contain 0-1% by weight, or 1-2% by weight, or 2-3% by weight, or 3-4% by weight, or 4-5% by weight, or 5-6% by weight, or 6-7% by weight, or 7-8% by weight, or 8-9% by weight, or 9-10% by weight, or 10-11% by weight, or 11-12% by weight, or 12-13% by weight, or 13-14% by weight, or 14-15% by weight, or 15-16% by weight, or 16-17% by weight, or 17-18% by weight, or 18-19% by weight, or 19-20% by weight, of methacrylic acid, based on the total weight of the composition.

[0097] (Urethane (meth)acrylate oligomer) The composition may include at least one urethane (meth)acrylate oligomer.

[0098] The composition may comprise 0-7 wt% of at least one urethane (meth)acrylate oligomer, based on the total weight of the composition. If included, the composition comprises 0.1-7 wt%, preferably 3-6 wt%, of at least one urethane (meth)acrylate oligomer, based on the total weight of the composition. For example, the composition may comprise 0-1 wt%, or 1-2 wt%, or 2-3 wt%, or 3-4 wt%, or 4-5 wt%, or 5-6 wt%, or 6-7 wt%, or 7-8 wt%, or 8-9 wt%, or 9-10 wt%, of at least one urethane (meth)acrylate monomer, based on the total weight of the composition.

[0099] The urethane (meth)acrylate oligomer may be selected from aliphatic urethane diacrylate oligomers, preferably the urethane (meth)acrylate oligomer is an aliphatic urethane diacrylate.

[0100] The composition may further comprise at least one monofunctional reactive diluent.

[0101] The composition may contain 0 to 0.7% by weight of at least one monofunctional reactive diluent relative to the total weight of the composition, if present, the composition contains 0.1 to 0.7% by weight, preferably 0.3 to 0.7% by weight, relative to the total weight of the composition, of at least one monofunctional reactive diluent.

[0102] The monofunctional reactive diluent may be 2-(2-ethoxy-ethoxy)ethyl acrylate. The mixture of urethane (meth)acrylate monomer and monofunctional reactive diluent is composed of about 90% by weight of aliphatic urethane diacrylate and about 10% by weight of 2-(2-ethoxy-ethoxy)ethyl acrylate, based on the total weight of the mixture, and is sold by Sartomer under the trade name CN966H90®.

[0103] (viscosity) The photopolymerizable adhesive composition is preferably a liquid composition. The composition may have a viscosity of 100 to 10,000 mPa.s, preferably 500 to 5,000 mPa.s, more preferably 1,000 to 2,500 mPa.s. The viscosity may be measured according to the NF EN 12092 standard "Adhesives - Measurement of Viscosity" using a Brookfierd DVIII Ultra viscometer (spindle: SC4-27, rotation: 20 rpm, temperature: 25°C).

[0104] The glass transition temperature of the composition is preferably at least 85°C, preferably at least 90°C, more preferably at least 100°C.

[0105] In some particular embodiments, the composition may comprise (or consist of), by total weight of the composition: - 20 to 35% by weight, preferably 25 to 30% by weight, of at least one block copolymer, - 45 to 75% by weight, preferably 45 to 70% by weight, more preferably 45 to 65% by weight of at least one (meth)acrylate monomer having a glass transition temperature of at least 85°C; - 2 to 15% by weight, preferably 3 to 10% by weight, more preferably 4 to 6% by weight of at least one alkoxysilane (meth)acrylate monomer, - 0.1 to 5% by weight, preferably 0.5 to 4% by weight, more preferably 1 to 3% by weight of at least one photoinitiator, - 0 to 5% by weight, preferably 0.1 to 5% by weight, of at least one (meth)acrylate monomer having a glass transition temperature below 0°C, - 0 to 20% by weight, preferably 1 to 16% by weight, more preferably 3 to 12% by weight of methacrylic acid, - 0 to 7% by weight, preferably 0.1 to 7% by weight, more preferably 3 to 6% by weight of at least one urethane (meth)acrylate oligomer, % by weight, preferably 0.1 to 0.7% by weight, more preferably 0.3 to 0.7% by weight, of at least one monofunctional reactive diluent (or may consist of them).

[0106] In some particular embodiments, the composition comprises: at least one block copolymer, preferably at least one (meth)acrylic block copolymer, preferably a (meth)acrylic block copolymer having a triblock structure MBM, 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-tert-butylcyclohexyl methacrylate, dihydrodicyclopentadienyl acrylate, and mixtures thereof, preferably methyl methacrylate, at least one alkoxysilane (meth)acrylate monomer, preferably a monomer selected from the group consisting of trialkoxysilane (meth)acrylate monomers, preferably a trimethoxysilane (meth)acrylate monomer, preferably a monomer which is 3-(trimethoxysilyl)propyl acrylate, 3-(trimethoxysilyl)propyl methacrylate, trimethoxysilyl acrylate, trimethoxysilyl acrylate, and mixtures thereof, preferably a monomer which is 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-phenanthrenequinone, benzoyltrimethylgermane, dibenzoyldiethylgermane, bis-(4-methoxybenzoyl)diethylgermanium, and mixtures thereof, preferably a photoinitiator which is 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 butyl acrylate, optionally methacrylic acid monomers, - optionally at least one urethane (meth)acrylate monomer, preferably an oligomer selected from aliphatic urethane diacrylate oligomers, preferably an oligomer which is an aliphatic urethane diacrylate oligomer, - optionally comprising (or consisting of) at least one monofunctional reactive diluent, preferably a diluent which is 2-(2-ethoxy-ethoxy)ethyl acrylate.

[0107] (One-component composition) The composition may be a one-component composition, i.e. a ready-to-use composition. In contrast, the composition is preferably not a multi-component composition, i.e. a kit containing at least two separately packaged components, said components being intended to be mixed immediately before applying the resulting composition.

[0108] The one-component composition does not have to be prepared in the form of at least two separate components that are mixed immediately before use to prevent premature polymerization. The one-component composition contains at least one photoinitiator that can initiate polymerization of the composition immediately upon exposure to light radiation, particularly ultraviolet radiation (UV). To prevent premature or excessive polymerization, the composition must not be exposed to light.

[0109] (Adhesive products) In a second aspect, the present invention includes an adhesive product.

[0110] The adhesive article includes a photopolymerizable adhesive composition as described above and an opaque container to contain it in. By "opaque container" is meant a container the walls of which do not transmit light, particularly visible and ultraviolet light (below 600 nm), that may activate the photoinitiator.

[0111] The opaque container may be a container capable of containing the composition and maintaining its properties, particularly its adhesive properties. The use of an opaque container prevents the composition from being exposed to light, particularly UV light, prior to use, i.e. during storage and transport, thereby avoiding premature or premature polymerization.

[0112] The container may for example be selected from the group comprising a bottle or a tube.

[0113] <Adhesive> In a third aspect, the present invention relates to an adhesive, in particular an adhesive obtained from the above-mentioned photopolymerizable adhesive composition. By "adhesive" or "photopolymerizable adhesive composition" is meant an adhesive layer obtained by par application of a photopolymerizable adhesive composition, photopolymerizing it and optionally molding the adhesive thus obtained.

[0114] The adhesive is - applying a photopolymerizable adhesive composition as described above to at least one barrier layer and / or electronic or optoelectronic device; - photopolymerizing the applied photopolymerizable adhesive composition to obtain a polymerized adhesive; - optionally, shaping the polymerized adhesive.

[0115] The adhesive may be in the form of a film.

[0116] Application of the composition may be carried out by conventional application techniques, such as slot die coating, deep coating, ink jet printing, spin coating, spray coating, or doctor blading.

[0117] Photopolymerization of the composition may be carried out using a UV lamp that emits ultraviolet (UV) and visible light in a range that can activate the photoinitiator by exposure to the light, in particular without being absorbed by the barrier layer. A suitable UV lamp may be, for example, a UV source of the UV LED system Delolux® 03S type. Photopolymerization may be carried out for 1 to 10 minutes.

[0118] The optional shaping of the adhesive may be carried out, for example, by a thermoforming process.

[0119] The thickness of the adhesive is 10 to 200 μm, preferably 10 to 100 μm, and more preferably 10 to 30 μm.

[0120] The adhesives have several advantages, particularly for use at temperatures 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 needs to meet temperature test standards (e.g., automotive applications).

[0121] The adhesive preferably has satisfactory adhesion properties, especially to allow satisfactory adhesion between the electronic or optoelectronic device and the barrier layer, even in the case of flexible modules.

[0122] The adhesive preferably has satisfactory optical properties, in particular a satisfactory transparency, in particular to allow transmission of light waves to the device and / or to limit diffraction of light waves, in particular when the electronic or optoelectronic device is a photovoltaic cell. The adhesive may have a transparency of 90% at a transmission of 400-800 nm. The transparency may be measured by UV-visible transmission spectroscopy.

[0123] The adhesive preferably has satisfactory electrical properties, in particular satisfactory electrical insulation properties, in order to prevent short circuits inside the module, which may be measured according to the ASTM D149 standard.

[0124] The adhesive preferably has satisfactory strength, especially with respect to ageing under UV radiation, abrasion and / or impact.

[0125] The adhesive preferably has satisfactory barrier properties, in particular water and oxygen (air) barrier properties. The barrier properties are measured according to the ASTM F 1249 standard at a temperature of 38°C and a relative humidity of 85%, with a water vapor transmission rate of 5 g / mm thickness. -2 .j -1 Less than 2g, preferably. -2 .j -1 It is preferable that the above is less than 100%.

[0126] The adhesive preferably has satisfactory elastic properties. The elastic properties, especially the flexibility, may be measured by a three or four point bending test using a bending tester with a cylindrical mandrel or by tensile strength measurements.

[0127] <Electronic or optoelectronic module> In a fourth aspect, the present invention relates to a module, preferably a flexible module, which corresponds to an encapsulated electronic or optoelectronic device.

[0128] The module may be obtained by assembling a series of layers one on top of the other.

[0129] The series of layers is a first barrier layer, a first adhesive as defined above or obtained from a photopolymerizable adhesive composition as defined above, - electronic or optoelectronic devices, a second adhesive as defined above or obtained from the photopolymerizable adhesive composition defined above, and a second barrier layer,

[0130] The electronic or optoelectronic device itself may include a semiconductor layer deposited on a supporting substrate.

[0131] This series of layers may further include additional layers, particularly layers interposed between the barrier layer and the adhesive, such as additional layers or surface treatments of the barrier layer that improve adhesion between the inner surface of the barrier layer and the layer of adhesive composition.

[0132] In the resulting module, the electronic or optoelectronic device is preferably coated with two superimposed adhesive layers on its outer surface to form a seal. The electronic or optoelectronic device is coated with adhesive and encapsulated with two barrier layers to insulate the device from the environment.

[0133] The resulting module has sufficient properties to limit or even prevent both perpendicular and lateral permeation while maintaining the flexibility of the electronic or optoelectronic device.

[0134] The module may have a total thickness of 50 to 500 μm, preferably 50 to 300 μm, more preferably 50 to 150 μm.

[0135] The electronic or optoelectronic device may be selected from a rigid device, a flexible device, or a combination thereof, preferably the device is a flexible device, preferably the device is selected from an organic light emitting diode, an organic photovoltaic cell, an organic transistor, or an organic sensor.

[0136] In one particular embodiment, the photovoltaic cell is a perovskite device. So-called halide perovskite materials may contain metals (e.g., lead or tin), organic and inorganic cations (e.g., cesium, formamidinium and / or ammonium), and halide anions (e.g., boron or iodine) in their crystal structure. Perovskite devices are particularly suitable for photovoltaic applications. However, perovskite devices may suffer from stability problems over time due to their sensitivity to air, especially water vapor.

[0137] The barrier layers may be the same or different.

[0138] The barrier layer may be a single layer or a multilayer.

[0139] The barrier layer may be flexible or rigid, preferably flexible.

[0140] The module may be oriented and may, for example, include a lower barrier layer and an upper barrier layer known as a backsheet and a frontsheet, the frontsheet preferably being transparent and the backsheet preferably being opaque.

[0141] Depending on the electronic or optoelectronic device used and the desired properties and characteristics of the module, the barrier layer may have specific characteristics.

[0142] The barrier layer may be a polymer.

[0143] The barrier layer may be inorganic.

[0144] The polymeric barrier layer may comprise at least one fluorinated polymer layer derived from at least one fluorinated polymer, such as polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), and mixtures thereof.

[0145] The polymeric barrier layer may comprise at least one polymer layer derived from polyethylene terephthalate (PET) (or PET layer).

[0146] The polymeric barrier layer may include at least one polymer layer derived from ethylene vinyl acetate (EVA) (or EVA layer).

[0147] A single barrier layer may include a layer selected from a fluorinated polymer layer, a PET layer, or an EVA layer. A multi-layer barrier layer may include at least two layers, preferably three layers, selected from a fluorinated polymer layer, a PET layer, an EVA layer, or a combination thereof. For example, a three-layer barrier layer may include a fluorinated polymer layer / PET layer / fluorinated polymer layer, or a fluorinated polymer layer / PET layer / EVA layer.

[0148] Fluorinated polymer layers, PET layers, EVA layers, and combinations thereof, as well as single or multi-layer barrier layers derived therefrom, are particularly suitable for use as the frontsheet or backsheet.

[0149] The barrier layer may include at least one glass layer.

[0150] The barrier layer may include at least one polymer layer derived from poly(methyl methacrylate) (PMMA) (or a PMMA layer).

[0151] A glass layer or a PMMA layer is particularly suitable for use as a front sheet or a back sheet.

[0152] A flexible barrier layer that is particularly suitable for encapsulating flexible electronic or optoelectronic devices, particularly organic photovoltaic cells such as perovskite-type devices, is marketed by 3M® under the trade name 3M Ultra-Barrier Solar Film. This barrier film is a laminated multilayer film that includes a PET film, an inorganic barrier layer, a pressure sensitive adhesive film (PSA), and a fluoropolymer film.

[0153] <Method of obtaining an electronic or optoelectronic module> In a fifth aspect, the present invention relates to a method for obtaining a module as defined above, said method comprising the following steps: - providing an electronic or optoelectronic device; - providing a photopolymerizable adhesive composition as described above; - providing a first barrier layer; - providing a second barrier layer; - applying a layer of a photopolymerizable adhesive composition to a surface of the device and / or to the inner surface of each of the first and second barrier layers; - laminating the device and a layer of a photopolymerizable adhesive composition between the inner surfaces of the first and second barrier layers, respectively; - photopolymerizing the layer of photopolymerizable adhesive composition.

[0154] The method may further comprise the step of irradiating the first barrier layer and / or the second barrier layer with UV-ozone prior to the coating and / or laminating steps.

[0155] In one particular embodiment, the rigid module is obtained by a vacuum lamination technique under temperature control, the so-called "sheet-to-sheet" lamination.

[0156] In one particular embodiment, the flexible module is obtained by a "roll-to-roll" technique, as described for example in the article by S. Razza et al. "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 suitable for flexible electronic or optoelectronic devices. Preferably, the devices are selected from organic light-emitting diodes, organic photovoltaic cells, organic transistors or organic sensors, preferably perovskite devices.

[0157] <Use and application> In a sixth aspect, the present invention relates to the use of a photopolymerizable adhesive composition as described above and an adhesive obtained therefrom as described above for the encapsulation of an electronic or optoelectronic device, in particular the encapsulation of a flexible electronic or optoelectronic device, such as an organic photovoltaic device, in particular a perovskite device.

[0158] <Example> The following examples are illustrative of the present invention but are not intended to limit it.

[0159] (List of materials and equipment) Block copolymer: MBM-triblock copolymer (polymethyl methacrylate-poly(styrene-co-butyl acrylate)-polymethyl methacrylate block copolymer) (abbreviation: MBM).

[0160] (Meth)acrylate monomer having a glass transition temperature of at least 85°C: methyl methacrylate (abbreviation: MAM).

[0161] Alkoxysilane (meth)acrylate monomer: Trimethoxysilane acrylate (Silquest® from Momentive®) (abbreviation: A174).

[0162] Photoinitiator: phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (Irgacure® 819 from Ciba® Specialty Chemicals, also available from Sigma-Aldrich) (abbreviation: I819).

[0163] (Meth)acrylate monomer having a glass transition temperature below 0°C: butyl acrylate (abbreviation: ABu).

[0164] Methacrylic acid (abbreviation: AMA).

[0165] Urethane (meth)acrylate oligomer: Aliphatic urethane diacrylate (CN966H90® from Sartomer) in 10% by weight of 2-(2-ethoxy-ethoxy)ethyl acrylate (abbreviation: CN966).

[0166] Commercially available compositions: delo® katiobond® from Delo.

[0167] Light source: UV LED system Delolux® 03S.

[0168] (Test module) The module under test is commonly called a test specimen.

[0169] PK layer: surface area 4 x 4 cm (16 cm 2 ) with the formula Cs 0.05 FA 0.95 Pb(I 0.88 Br 0.12 ) 3 perovskite layer.

[0170] Glass layer: surface area 5×5 (25cm 2 ) layer.

[0171] ITO layer: Tin-doped indium oxide layer.

[0172] SnO 2 Layer: Tin dioxide layer.

[0173] Glass, ITO and / or SnO 2 The layer itself forms the supporting substrate.

[0174] Multilayer module 1: Glass / ITO / SnO 2 / PK.

[0175] Multilayer module 2: Glass / ITO / PK / ITO.

[0176] SnO 2 and / or PK layers were deposited by spin coating technique. The top ITO layer (module 2) was deposited by physical vapor deposition.

[0177] The perovskite layer was deposited on a supporting substrate with a 5 mm overhang between the edge of the substrate and the perovskite layer.

[0178] The photopolymerizable compositions under test were used to individually encapsulate the modules between two 1.2 mm thick glass barrier layers.

[0179] (Test Method) The thermal and gas barrier properties of the test modules were analyzed by differential scanning calorimetry (DSC). Three cooling and heating cycles were performed in the range of -80 to 200°C at a rate of 10°C per minute. In the third heating cycle, the glass transition temperature was determined by calculating the half-value tangent method between 40 and 140°C.

[0180] The degradation rate (cm) related to the degradation of the perovskite layer 2The degradation of the test module was evaluated as follows: the test specimen was placed in an artificial climate chamber at a temperature of 85° C. and a relative humidity of 85%, which corresponds to the test climate conditions for photovoltaic modules according to the IEC 61615 standard method, and the degradation rate (cm 2 The algorithm parameters of the perovskite test were measured; see the paper by E. Booker et al.: "Perovskite test: A high throughput method to screen ambient encapsulation conditions", Energy Technology (2020) 8(12). To assess the ageing of the perovskite layer, photographs of the test specimens were taken periodically, e.g. every 48 hours. The residual surface (thickness) of the perovskite layer was measured and the thickness was determined at 12 cm 2 2cm from 2 The degradation rates (cm) of these layers were calculated from the linear regression of the points between 2 / h) was calculated. Areas with a thickness of 180 nm or less were considered as degraded areas (black areas, algorithmic analysis), and areas with a thickness of more than 180 nm were considered as intact areas (gray areas, algorithmic analysis).

[0181] (Photopolymerizable adhesive composition) The following photopolymerizable adhesive compositions were prepared (see Table 1, where the numbers in Table 1 are percentages, expressed as weight percent based on the total weight of the photopolymerizable adhesive composition).

[0182] [Table 1]

[0183] Compositions CExA and CExB are comparative examples.

[0184] (Test 1) In test 1, the degradation rate of a multilayer module 1 obtained with composition Ex1 (example) and compositions CExA and CExB (comparison examples) was studied. Two series of tests were carried out for each composition.

[0185] These compositions differ, taking into account the same 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 of less than 0° C., in particular in the proportion of (meth)acrylate monomers having a glass transition temperature less than 0° C. (here butyl acrylate).

[0186] The glass transition temperatures of the tested compositions were: composition CExA 62.6° C., composition CExB 75.7° C., and composition Ex1 94.14° C. The glass transition temperature of composition Ex5 (example) was 86.2° C.

[0187] Photographs were taken periodically of the tested modules at 0, 159, 280, 351, 447, 521, 624, 737, 852, 948 and 1091 hours, as shown in Figure 1 (first row corresponds to the photographs, second row corresponds to the images after computer analysis).

[0188] The degradation rate correlated with the decrease in perovskite surface area over time compared to the surface area of ​​undegraded perovskite (0 time), allowing the comparison of the effect of different compositions on lateral penetration.

[0189] As shown in FIG. 2, unlike composition Ex1, in this test, comparative compositions having a high proportion of (meth)acrylate monomers with glass transition temperatures below 0° C. exhibit poor glass transition temperatures, high degradation rates, and high lateral permeability.

[0190] Furthermore, the tested modules of the present invention have a solubility of 2 g.mm.M according to the method described in the article by A. Kovrov et al. "Novel acrylic monomers for organic photovoltaics encapsulation", Solar Energy Materials & Solar Cells (2020) 110210. -2 .d-1 This indicates the water vapor transmission rate.

[0191] (Test 2) In test 2, the degradation rate of the multilayer modules 2 obtained with compositions Ex1 to 3 (examples) was investigated. Two series of tests were carried out for each composition.

[0192] These compositions differ in particular in the proportion of block copolymers.

[0193] Photographs were taken periodically of the tested module, at 0 hours, 265 hours, 505 hours, 771 hours, and 1002 hours, as shown in Figure 3 (each row corresponds to a photograph).

[0194] This test showed no significant differences in the degradation rates of the three modules tested, confirming that the proportions of these block copolymers do not adversely affect the gas barrier properties of the adhesive composition or its glass transition temperature, while maintaining satisfactory elasticity (flexibility).

[0195] (Test 3) In test 3, the photoaging under continuous sunlight (sun spectrum: AM1.5) of an adhesive layer approximately 200 μm thick obtained from composition Ex1 (example) was tested in comparison with a layer 200 μm thick obtained from a commercial composition (delo® katiobond® Ip655).

[0196] The photoaging and possible yellowing of the layer was measured from 0 to 1600 hours, as shown in the graph of Figure 4. The open circles (white) correspond to the data for the commercial composition at 1600 hours, the closed circles (black) correspond to the data for the commercial composition at 0 hours, the open triangles (white) correspond to the data for composition Ex1 at 1600 hours, and the closed triangles (black) correspond to the data for composition Ex1 at 0 hours.

[0197] This test shows that the layer obtained from the commercial composition yellows significantly, which inevitably leads to a reduced range of light transmission, unlike the adhesive layer obtained from composition Ex1 (example).

Claims

1. A photopolymerizable adhesive composition comprising: based on the total weight of the photopolymerizable adhesive composition, 20 to 35 wt. % of at least one block copolymer; 45 to 75 wt. % of at least one (meth)acrylate monomer having a glass transition temperature (Tg) of at least 85°C; 2 to 15 wt. % of at least one alkoxysilane (meth)acrylate monomer; and 0.1 to 5 weight percent of at least one photoinitiator.

2. the block copolymer is selected from the group consisting of block copolymers having at least one block M and at least one block B; the block M represents a block polymer containing at least 50% by weight of methyl methacrylate; The photopolymerizable adhesive composition according to claim 1 , wherein the block B is an elastomeric block polymer that is incompatible with the block M and has a glass transition temperature (Tg) of less than 20° C.

3. 2. The photopolymerizable adhesive composition of 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, isobornyl methacrylate, isobornyl acrylate, cyclohexyl methacrylate, 4-tert-butylcyclohexyl methacrylate, dihydrodicyclopentadienyl acrylate, and mixtures thereof.

4. The photopolymerizable adhesive composition of claim 1 , wherein the alkoxysilane (meth)acrylate monomer is selected from the group consisting of trialkoxysilane (meth)acrylate monomers.

5. 10. The photopolymerizable adhesive composition of claim 1, further comprising at least one (meth)acrylate monomer having a glass transition temperature below 0°C, a methacrylic acid monomer, at least one urethane (meth)acrylate oligomer, at least one monofunctional reactive diluent, and mixtures thereof.

6. The photopolymerizable adhesive composition according to claim 5, wherein the (meth)acrylate monomer having a glass transition temperature of less than 0°C, when 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.

7. The photopolymerizable adhesive composition of claim 1 which is a one-component composition.

8. The photopolymerizable adhesive composition of claim 1 having a glass transition temperature of at least 85°C.

9. An adhesive product comprising the photopolymerizable adhesive composition according to any one of claims 1 to 8 and an opaque container for containing the same.

10. - applying a photopolymerizable adhesive composition according to any one of claims 1 to 8 to at least one barrier layer and / or at least one electronic or optoelectronic device; - photopolymerizing the applied photopolymerizable adhesive composition to obtain a polymerized adhesive; A method for obtaining an adhesive comprising:

11. a first barrier layer, a first adhesive obtained from a photopolymerizable adhesive composition according to any one of claims 1 to 8, - flexible electronic or optoelectronic devices, a second adhesive obtained from the photopolymerizable adhesive composition according to any one of claims 1 to 8, and - a second barrier layer.

12. 12. The electronic or optoelectronic module of claim 11, wherein the flexible electronic or optoelectronic device is selected from an organic light emitting diode, an organic photovoltaic cell, an organic transistor, or an organic sensor.

13. 12. The electronic or optoelectronic module of claim 11, wherein the flexible electronic or optoelectronic device is a perovskite-based device.

14. A method for obtaining a module according to claim 11, comprising the steps of: - providing an electronic or optoelectronic device; - providing said photopolymerizable adhesive composition; - providing a first barrier layer; - providing a second barrier layer; - applying a layer of said photopolymerizable adhesive composition to the surface of said device and / or to the inner surface of each of said first and second barrier layers; - laminating the device and a layer of the photopolymerizable adhesive composition between the inner surfaces of the first and second barrier layers, respectively; - photopolymerizing the layer of photopolymerizable adhesive composition.

15. Use of the photopolymerizable adhesive composition according to any one of claims 1 to 8 for the encapsulation of flexible electronic or optoelectronic devices.

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