Photopolymerizable adhesive composition for encapsulating electronic or optoelectronic devices

Abstract

The invention relates to a photopolymerizable adhesive composition comprising, by weight per total weight of the photopolymerizable adhesive composition: from 20 to 35% of at least one block copolymer, preferably a (meth)acrylic block copolymer; from 45 to 75% of a mixture P of (meth)acrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature (Tg) of at least 85°C, said mixture P comprising at least one methacrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature (Tg) of at least 85°C and at least 5% by weight of a mono-acrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature (Tg) of at least 85°C; from 2 to 15% of at least one alkoxysilane (meth)acrylate monomer; and 0.1 to 5% of at least one photoinitiator. No figure.

Description

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

[0001] The present invention relates to adhesive photopolymerizable compositions for use in the encapsulation of electronic and optoelectronic devices, in particular flexible electronic and optoelectronic devices, for example organic and perovskite 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, organic, perovskite, or CIGS semiconductors.

[0006] Various encapsulation techniques have been implemented. These generally include coating the device with an adhesive composition to obtain a coated device, and then laminating the coated device between two covers. to obtain 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, shock 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 operating stresses, etc. The properties of the adhesive must therefore be optimized to minimize or even eliminate the lateral permeation of gases from the atmosphere (in particular water vapor and oxygen), 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 with satisfactory properties These properties include, in particular, satisfactory 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.Finally, there is an advantage to providing such an adhesive composition with rapid polymerization and a high monomer-to-polymer conversion rate. Summary of the invention

[0013] This application relates primarily to a photopolymerizable adhesive composition comprising, by weight per total weight of the photopolymerizable adhesive composition:

[0014] of 20 to 35% of at least one block copolymer, preferably a (meth)acrylic block copolymer;

[0015] of 45 to 75% of a mixture P of (meth)acrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature (Tg) of at least 85°C, said mixture P comprising at least one methacrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature (Tg) of at least 85°C and at least 5% by weight of a mono-acrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature (Tg) of at least 85°C;

[0016] of 2 to 15% of at least one alkoxysilane (meth)acrylate monomer; and

[0017] of 0.1 to 5% of at least one photoinitiator.

[0018] Preferably, the block copolymer is chosen from the group consisting of block copolymers comprising at least one M block and at least one B block;

[0019] said block M designating a polymer block comprising at least 50% by weight of methyl methacrylate; and

[0020] block B designating an elastomeric polymer block incompatible with block M, and whose glass transition temperature (Tg) is less than 20°C.

[0021] In one embodiment, the mixture P comprises at least one methacrylate monomer whose homopolymer obtained after polymerization has a temperature of glass transition of at least 85°C selected from the group consisting of methyl methacrylate, tert-butyl methacrylate, phenyl methacrylate, isopropyl methacrylate, isobornyl methacrylate, cyclohexyl methacrylate, 4-ter-butylcyclohexyl methacrylate, and mixtures thereof, preferably the methacrylate monomer is methyl methacrylate; and at least 5% by weight relative to the total weight of mixture P of an acrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature (Tg) of at least 85°C chosen from isobornyl acrylate, dihydrodicyclopentadienyl acrylate, and mixtures thereof, preferably the acrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature (Tg) of at least 85°C is isobornyl acrylate.

[0022] In one embodiment, the mixture P further comprises at least one diacrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature (Tg) of at least 85°C, preferably said diacrylate monomer is selected from dipropylene glycol diacrylate, neopentylglycolhydroxypivalate diacrylate, tricyclodecanedimethanol diacrylate, preferably the diacrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature of at least 85°C is tricyclodecanedimethanol diacrylate (TCDDMDA).

[0023] Preferably, mixture P comprises:

[0024] - from 20% to 95% by weight, more preferably from 20% to 80% by weight, and even more preferably from 30% to 70%, preferably from 40% to 60%, by weight relative to the weight of mixture P, of at least one methacrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature (Tg) of at least 85°C;

[0025] - at least 5%, preferably at least 10%, more preferably from 5 to 80%, more preferably from 20% to 80%, even more preferably from 30% to 70%, preferably from 40% to 60% by weight of a mono-acrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature (Tg) of at least 85°C; and

[0026] of 1 to 20% by weight, more preferably of 1 to 10% by weight, preferably of 1 to 5% by weight, of at least one diacrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature of at least 85°C.

[0027] In one embodiment, the alkoxysilane (meth)acrylate monomer is chosen from the group consisting of the trialkoxysilane (meth)acrylate monomers.

[0028] Preferably, the composition according to the invention comprises, preferably consists of, by weight per total weight of the composition:

[0029] - from 25 to 35%, preferably from 28 to 32%, of at least one block copolymer;

[0030] - from 45 to 65%, of a mixture P of (meth)acrylate monomers of which the homopolymer obtained after polymerization has a glass transition temperature of at least 85°C, said mixture P comprising 40 to 60% by weight of a methacrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature of at least 85°C, preferably methyl methacrylate, and 40 to 60% by weight of a mono-acrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature of at least 85°C, preferably isobornyl acrylate or dihydrodicyclopentadienyl acrylate and 0 to 10% by weight, preferably 0 to 5% by weight of a diacrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature of at least 85°C, preferably TCDDMDA;

[0031] -from 3 to 10%, preferably from 4 to 6%, of at least one alkoxysilane (meth)acrylate monomer, preferably trimethoxysilane acrylate;

[0032] - from 0.5 to 4%, preferably from 1 to 3%, of at least one photoinitiator;

[0033] - from 1 to 16%, preferably from 3 to 15%, of methacrylic acid.

[0034] Preferably, the composition of the invention comprises, preferably consists of, by weight per total weight of the composition:

[0035] - from 28 to 32%, of at least one block copolymer;

[0036] - from 45 to 65%, of a mixture P of (meth)acrylate monomers of which the homopolymer obtained after polymerization at a glass transition temperature of at least 85°C, said mixture P comprising 40 to 60% by weight of methyl methacrylate, and 40 to 60% by weight preferably of isobornyl acrylate and 0 to 5% by weight of TCDDMDA;

[0037] - 4 to 6% of trimethoxysilane acrylate;

[0038] - from 1 to 3%, of at least one photoinitiator;

[0039] - 3 to 15%, methacrylic acid.

[0040] In one embodiment, the composition is a single-component composition.

[0041] Preferably, the composition of the invention has a glass transition temperature after polymerization of at least 85°C, preferably at least 90°C, more preferably at least 100°C.

[0042] The invention also relates to an adhesive product comprising the adhesive photopolymerizable composition according to the invention and an opaque container containing it.

[0043] The invention also relates to an adhesive obtained by the process comprising the following steps:

[0044] application of a photopolymerizable adhesive composition according to the invention on at least one hood and / or an electronic or optoelectronic device;

[0045] photopolymerization of the applied adhesive photopolymerizable composition to obtain a polymerized adhesive; and

[0046] optionally shaping of the polymerized adhesive.

[0047] The present application also relates to an electronic or optoelectronic module comprising the assembly of a series of layers including, in this order:

[0048] a first hood;

[0049] a first adhesive according to the invention or obtained from the adhesive photopolymerizable composition according to the invention;

[0050] a flexible electronic or optoelectronic device;

[0051] a second adhesive according to the invention or obtained from the photopolymerizable adhesive composition according to the invention; and

[0052] a second hood.

[0053] Preferably, the electronic or optoelectronic module according to which the flexible electronic or optoelectronic device is chosen from organic light-emitting diodes, organic photovoltaic cells, organic transistors, or organic sensors, or a combination of these devices.

[0054] Preferably, the electronic or optoelectronic module according to which the flexible electronic or optoelectronic device is a perovskite-type device.

[0055] The application also relates to a method for obtaining the module according to the invention, the method comprising the following steps:

[0056] the supply of an electronic or optoelectronic device;

[0057] the supply of a photopolymerizable adhesive composition according to the invention;

[0058] the supply of a first hood;

[0059] the supply of a second hood;

[0060] the application of layers of adhesive photopolymerizable composition to the surface of the device and / or to respective internal surfaces of the first and second caps

[0061] the lamination of the device and the layers of adhesive photopolymerizable composition between the respective internal surfaces of the first and second caps; and

[0062] the photopolymerization of the layers of adhesive photopolymerizable composition.

[0063] The present application also relates to the use of the photopolymerizable adhesive composition according to the invention, or of the adhesive according to the invention, for the encapsulation of flexible electronic or optoelectronic devices.

[0064] The inventors have shown that a combination of methacrylate monomer, the homopolymer of which obtained after polymerization has a glass transition temperature (Tg) of at least 85°C, and monoacrylate monomer, the homopolymer of which obtained after polymerization has a glass transition temperature (Tg) of at least 85°C, and optionally diacrylate monomer, the homopolymer of which obtained after polymerization has a glass transition temperature (Tg) of at least 85°C, advantageously improves the polymerization kinetics and the conversion of the The adhesive photopolymerizable composition of the invention, compared to a composition comprising only a methacrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature (Tg) of at least 85°C, advantageously improves industrial productivity for the manufacture of electronic or optoelectronic modules. The inventors have also advantageously demonstrated that this combination limits shrinkage associated with the polymerization of the photopolymerizable composition. Description of the figures

[0065] [Fig-1] represents the evolution of the area of ​​the active surface as a function of time for the reference composition (CExC) and compositions 1 and 2 according to the invention (respectively Exl and Ex2).

[0066] [Fig.2] represents the VA for the reference composition (CExC) and the com positions 1 and 2 according to the invention (respectively Exl and Ex2).

[0067] [Fig.3] represents the DA12 for the reference composition (CExC) and compositions 1 and 2 according to the invention (respectively Exl and Ex2).

[0068] [Fig.4] represents the evolution of the average thickness of the active surface as a function time for the reference composition (CExC) and compositions 1 and 2 according to the invention (respectively Exl and Ex2).

[0069] [Fig.5] represents the VE for the reference composition (CExC) and compositions 1 and 2 according to the invention (respectively Exl and Ex2).

[0070] [Fig.6] represents DE380 for the reference composition (CExC) and compositions 1 and 2 according to the invention (respectively Exl and Ex2). Detailed description

[0071] The invention is now described in more detail and in a non-limiting manner in the following description.

[0072] Unless otherwise indicated, all percentages are mass percentages.

[0073] In this text, the quantities indicated for a given species may apply to that species according to all its definitions (as mentioned in this text), including more restricted definitions.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] By "module", we mean the assembly of the electronic or optoelectronic device coated by the polymerized adhesive composition and interposed between the two hoods.

[0078] 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".

[0079] 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.

[0080] By "photopolymerizable adhesive composition" advantageously means a composition which develops adhesive properties when subjected to electromagnetic radiation, in particular to ultraviolet (UV) radiation, which initiates (primes) its polymerization.

[0081] 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.

[0082] By "polymerization" is meant a process of transforming a single type of monomer or a mixture of different types of monomers into a polymer.

[0083] By "polymer" we mean a copolymer or a homopolymer.

[0084] By “homopolymer”, we mean a polymer grouping together several identical monomer units.

[0085] By “copolymer” we mean a polymer combining at least two different types of monomer units (designated co-monomers).

[0086] By "oligomer" is meant a small polymeric compound obtained by polymerization of 2 to 30 monomers (comprising 2 to 30 monomer units), that is to say whose degree of polymerization is between 2 and 30.

[0087] 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.

[0088] By "(meth)acrylic" (or "(meth)acrylate"), we mean any type of compound, Polymers, monomers or oligomers, acrylic and / or methacrylic (or acrylates and / or methacrylates). For example, (meth)acrylic acid means acrylic acid or methacrylic acid, isobornyl (meth)acrylate refers to isobornyl acrylate or isobornyl methacrylate, etc.

[0089] By “polymerization” we mean a chemical process which allows molecules to be linked together to form a three-dimensional network.

[0090] 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.

[0091] By "Tg", we mean the glass transition temperature of the polymer material. The glass transition temperature can be measured by differential scanning calorimetry (DSC), for example, using the tangent at half maximum (TmH) method measured between two inflection points located between 40 and 140°C, during the third heating cycle. In the context of the present invention, certain monomers are described by the Tg that the homopolymers obtained after polymerization of said monomers would have. In this case, the Tg is measured as follows: the monomer is polymerized to maximum conversion, thus forming the homopolymer; the measurement of the Tg of the resulting homopolymer is carried out by DSC as mentioned above.

[0092] By "room temperature" is meant a temperature of about 20°C.

[0093] 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 weight per total weight of the composition. Adhesive photopolymerizable composition

[0094] In a first aspect, the present invention relates to an adhesive photopolymerizable composition. block copolymer

[0095] The composition comprises at least one block copolymer, preferably at least one (meth)acrylic block copolymer.

[0096] The composition may comprise from 20 to 35%, preferably from 25 to 35%, even more preferably from 28% to 32% of at least one block copolymer, by weight by total weight of the composition.

[0097] 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 weight per total weight of the copolymer. The non- (Meth)acrylic can be chosen from the group consisting of butadiene, isoprene, styrene, vinylnaphthalene, a cyclosiloxane monomer, vinylpyridine and their derivatives (e.g. α-methylstyrene or tert-butylstyrene).

[0098] 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.

[0099] 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 weight per total weight of block M.

[0100] 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.

[0101] 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 weight by total weight of block M.

[0102] The other monomer, different from methyl methacrylate, constituting block M, may be another (meth)acrylic monomer or a non-(meth)acrylic monomer.

[0103] The non-(meth)acrylic monomer can 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).

[0104] 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, isobotyl (meth)acrylate, amides derived from (meth)acrylic acid (e.g., N,N-dimethylacrylamide), 2-methoxyethyl (meth)acrylate, 2-aminoethyl (meth)acrylate, polyethylene glycol (PEG) (meth)acrylate, in of which the PEG group has a molar mass ranging from 400 to 10,000 g / mol, and their mixtures.

[0105] 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 weight per total weight of block B.

[0106] The alkyl (meth)acrylate can be selected from the group consisting of ethyl acrylate (Tg of the homopolymer obtained after polymerization = -24°C), butyl acrylate (Tg of the homopolymer obtained after polymerization = -54°C), 2-ethylhexyl acrylate (Tg of the homopolymer obtained after polymerization = -85°C), hydroxyethyl acrylate (Tg of the homopolymer obtained after polymerization = -15°C), 2-ethylhexyl methacrylate (Tg of the homopolymer obtained after polymerization = -10°C) and mixtures thereof; preferably the alkyl (meth)acrylate is butyl acrylate.

[0107] The other monomer, different from alkyl (meth)acrylate, may be chosen from the group consisting of butadiene, isoprene, styrene, vinylnaphthalene, a cyclosiloxane monomer, vinylpyridine and their derivatives (for example Ta-methylstyrene or tert-butylstyrene).

[0108] The dibloc BM copolymer may have a number-average molar mass between 10,000 and 500,000 g / mol, preferably between 20,000 and 200,000 g / mol.

[0109] The diblock copolymer BM may comprise a mass fraction (by weight per 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.

[0110] 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.

[0111] Block B consists of the same monomers (or co-monomers) as block B of the dibloc BM copolymer as described above.

[0112] The MBM triblock copolymer may 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.

[0113] The MBM triblock copolymer may comprise a mass fraction (by weight per 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- typically between 30 and 85%, preferably between 40 and 60%, in block B.

[0114] Preferably, the MBM triblock copolymer is a polymethyl-methacrylate-poly(styrene-co-butylacrylate)-polymethylmethacrylate block copolymer.

[0115] 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.

[0116] One or less of blocks M and B can be functionalized by means of one or more functions selected from the group consisting of acid, amine, amide, epoxy, thiol functions, quaternary ammonium groups, chlorinated groups and fluorinated groups.

[0117] Block copolymers are commercially available under the name Nanostrength® by Arkema. Monoacrylate monomers

[0118] The composition comprises from 45 to 75% by weight, relative to the total weight of the composition, of a mixture P of (meth)acrylate monomers of which the homopolymer obtained after polymerization has a glass transition temperature (Tg) of at least 85°C, said mixture P comprising at least one methacrylate monomer of which the homopolymer obtained after polymerization has a glass transition temperature (Tg) of at least 85°C and at least 5% by weight of an acrylate monomer of which the homopolymer obtained after polymerization has a glass transition temperature (Tg) of at least 85°C.

[0119] The composition of the invention comprises preferably from 45 to 75%, preferably from 45 to 70%, even more preferably from 45 to 65%, of mixture P, by weight by total weight of the composition.

[0120] Preferably, mixture P comprises:

[0121] - from 20% to 95% by weight, more preferably from 20% to 80% by weight, and even more preferably from 30% to 70%, preferably from 40% to 60%, by weight relative to the weight of mixture P, of at least one methacrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature (Tg) of at least 85°C and

[0122] - at least 5%, preferably at least 10%, more preferably from 5 to 80%, more preferably from 20% to 80%, even more preferably from 30% to 70%, preferably from 40% to 60% by weight of a monoacrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature (Tg) of at least 85°C. Preferably, the amount by weight of monoacrylate monomer in mixture P is such that the viscosity of the resulting adhesive photopolymerizable composition according to the invention has a viscosity of 100 to 20,000 mPa·s, preferably a viscosity of 100 to 10,000 mPa·s, preferably from 500 to 5,000 mPa.s, more preferably from 1,000 to 2,500 mPa.s. 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).

[0123] The methacrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature of at least 85°C may be selected from the group consisting of methyl methacrylate, tert-butyl methacrylate, phenyl methacrylate, isopropyl methacrylate, isobornyl methacrylate, cyclohexyl methacrylate, 4-ter-butylcyclohexyl methacrylate, and mixtures thereof, preferably the methacrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature of at least 85°C is methyl methacrylate.

[0124] The mono-acrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature of at least 85°C can be chosen from the group consisting of isobornyl acrylate, dihydrodicyclopentadienyl acrylate, and their mixtures, preferably the acrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature (Tg) of at least 85°C is isobornyl acrylate.

[0125] The mixture P may further comprise from 0 to 40% by weight, preferably from 0 to 20% by weight or from 1 to 20% by weight, more preferably from 0 to 10% by weight or from 1 to 10% by weight, preferably from 0 to 5% by weight or from 1 to 5% by weight, of at least one diacrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature of at least 85°C, in particular dipropylene glycol diacrylate (CAS No. 57472-68-1), neopentylglycol hydroxypivalate diacrylate (CAS No. 2136366-99-7), tricyclodecanedimethanol diacrylate (CAS No. 52594-17-2), preferably the diacrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature of at minus 85°C is tricyclodecanedimethanol diacrylate (TCDDMDA). Alkoxysilane (meth)acrylate monomers

[0126] The composition comprises at least one alkoxysilane (meth)acrylate monomer.

[0127] 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 weight by total weight of the composition.

[0128] The alkoxysilane (meth)acrylate monomer, including the alkyl alkoxysilane (meth)acrylate monomer, may be selected from the group consisting of the tri-koxysilane (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, the 3-(trimethoxysilyl)propyl methacrylate, trimethoxysilyl acrylate, trimethoxysilyl methacrylate and mixtures thereof; preferably the alkoxysilane (meth)acrylate monomer is 3-(trimethoxysilyl)propyl methacrylate.

[0129] 3-(trimethoxysilyl)propyl methacrylate is commercially available under the name Silquest® A174 from Momentive®. Photoinitiator

[0130] 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.

[0131] 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 weight per total weight of the composition.

[0132] The photoinitiator may be selected from the group consisting of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, triethylbenzoyl-diphenyl-phosphine oxide, thioxanthen-9-one, 4,4-bis(diethylamino)benzophenone, 9,10-phenanthrene quinone, 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.

[0133] Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide is commercially available under the name Omnirad® 819 from IGM Resins (formerly Irgacure® 819 from Ciba® Specialty Chemicals). The mixture comprising benzophenone, α-hydroxyketone, and triethylbenzoyl-diphenylphosphine oxide is commercially available under the name Esacure® KTO 46 from Lehvoss. Other monomer (meth)acrylate

[0134] The composition may include at least one (meth)acrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature (Tg) below 0°C. In this embodiment, the composition comprises a mixture of a (meth)acrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature of at least 85°C and a (meth)acrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature below 0°C.

[0135] The composition may comprise from 0 to 5% of at least one monomer (Meth)acrylate whose homopolymer obtained after polymerization has a glass transition temperature below 0°C, by weight per total weight of the composition. If present, the composition may comprise from 0.1 to 5% of at least one (meth)acrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature below 0°C, by weight per total weight of the composition.

[0136] The (meth)acrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature below 0°C can 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.

[0137] Preferably, the composition can be substantially free of (meth)acrylate monomers whose homopolymer obtained after polymerization has a glass transition temperature (Tg) below 0°C. Methacrylic acid

[0138] The composition may include the monomer methacrylic acid.

[0139] It must be understood that the methacrylic acid monomer is not a methacrylate of mixture P.

[0140] The composition may comprise from 0 to 20% methacrylic acid, by weight per total weight of the composition. If present, the composition comprises from 1 to 16%, preferably from 3 to 15%, methacrylic acid, by weight per total weight of the composition.

[0141] Preferably, the composition comprises 5% to 12% methacrylic acid by weight relative to the total weight of the composition. Urethane (meth)acrylate oligomer

[0142] The composition may include at least one urethane (meth)acrylate oligomer.

[0143] The composition may comprise from 0 to 7% of at least one urethane (meth)acrylate oligomer, by weight per 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 weight per total weight of the composition.

[0144] Preferably, the composition is substantially free of urethane (meth)acrylate oligomer.

[0145] The urethane (meth)acrylate oligomer can be chosen from aliphatic diacrylate methane oligomers, preferably the urethane (meth)acrylate oligomer is aliphatic urethane diacrylate.

[0146] The composition may further comprise at least one mono- reactive diluent functional.

[0147] The composition may comprise from 0 to 0.7% of at least one monofunctional reactive diluent, by weight per 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 weight per total weight of the composition.

[0148] The monofunctional reactive diluent may be 2-(2-ethoxy-ethoxy) ethyl acrylate. The mixture of a urethane (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 weight per total weight of the mixture, is commercially available under the Sartomer brand name CN966H90®. Viscosity

[0149] The adhesive photopolymerizable composition is preferably a liquid composition.

[0150] The composition may have a viscosity of 100 to 20,000 mPa.s, preferably 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 standard NF EN 12092 "Adhesives - Determination of viscosity" using a Brookfield DVIII Ultra viscometer (mobile: SC4-27, rotation: 20 rpm, temperature: 25°C).

[0151] After polymerization, the composition has a glass transition temperature (Tg), preferably of at least 85°C, preferably of at least 90°C, preferably of at least 100°C.

[0152] Preferably, the composition comprises (alternatively consists 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 mixture P of (meth)acrylate monomers of which the homopolymer obtained after polymerization has a glass transition temperature of at least 85°C, said mixture P comprises at least one methacrylate monomer of which the homopolymer obtained after polymerization has a glass transition temperature of at least 85°C selected from the group consisting of methyl methacrylate, tert-butyl methacrylate, phenyl methacrylate, isopropyl methacrylate, isobornyl methacrylate, cyclohexyl methacrylate, 4-ter-butylcyclohexyl methacrylate, and mixtures thereof, preferably the methacrylate monomer is methyl methacrylate; and at least 5% by weight relative to the total weight of mixture P of a mono-acrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature (Tg) of at least 85°C selected from isobornyl acrylate, dihydrodicyclopentadienyl acrylate, and their mixtures, preferably the mono-acrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature (Tg) of at least 85°C is isobornyl acrylate and optionally 1% to 20% by weight of a diacrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature (Tg) of at least 85°C, preferably said diacrylate monomer is selected from dipropylene glycol diacrylate, neopentyl glycol hydroxypivalate diacrylate, tricyclodecanedimethanol diacrylate, preferably the diacrylate monomer is tricyclodecanedimethanol diacrylate; 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 methacrylate and mixtures thereof; preferably a monomer being 3-(trimethoxysilyl)propyl methacrylate; 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 quinone, benzoyltrimethylgermane, dibenzoyldiethylgermane, bis-(4-methoxybenzoyl)diethylgermanium and mixtures thereof; preferably a photoinitiator being phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, and mixtures thereof; - optionally at least one (meth)acrylate monomer whose homopolymer obtained after polymerization has 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 the 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.

[0153] Preferably, the composition comprises (alternatively is made up of), by weight per total weight of the composition: - 20 to 35%, preferably 25 to 35%, preferably 28 to 32%, of at least one block copolymer; - 45 to 75%, preferably 45 to 70%, preferably 45 to 65%, of a mixture P of (meth)acrylate monomers, the homopolymer of which obtained after polymerization has a glass transition temperature of at least 85°C, said mixture P comprising at least one methacrylate monomer, the homopolymer of which obtained after polymerization has a glass transition temperature of at least 85°C, and at least 5% by weight, preferably at least 10% by weight, preferably 5 to 80% by weight, more preferably 20 to 80% by weight, even more preferably 30 to 70% by weight, of a mono-acrylate monomer, the homopolymer of which obtained after polymerization has a glass transition temperature of at least 85°C, and optionally a diacrylate monomer, the homopolymer of which obtained after polymerization has 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; - 0 to 5% of at least one (meth)acrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature below 0°C;

[0154] from 0 to 20%, preferably from 1 to 16%, preferably from 3 to 15%, of methacrylic acid; and - 0 to 0.7% of at least one monofunctional reactive diluent.

[0155] Preferably, the composition comprises (alternatively is made up of), by weight per total weight of the composition: - 20 to 35%, preferably 25 to 30%, of at least one block copolymer; - from 45 to 75%, preferably from 45 to 70%, preferably from 45 to 65%, of a mixture P of (meth)acrylate monomers, the homopolymer of which obtained after polymerization has a glass transition temperature of at least 85°C, said mixture P comprising at least one methacrylate monomer, the homopolymer of which obtained after polymerization has a glass transition temperature of at least 85°C and at least 5% by weight, of preferably at least 10% by weight, preferably 5 to 80% by weight, more preferably 20 to 80% by weight, even more preferably 30 to 70% by weight, of a mono-acrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature of at least 85°C and optionally, 0 to 40% by weight, preferably 1 to 20% by weight, of a diacrylate monomer whose homopolymer obtained after polymerization has 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; - 0 to 5% of at least one (meth)acrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature below 0°C; - from 0 to 20%, preferably from 1 to 16%, preferably from 3 to 15%, of methacrylic acid; - 0 to 0.7% of at least one monofunctional reactive diluent.

[0156] Preferably, the composition comprises (alternatively is made up of), by weight per total weight of the composition: - 25 to 35%, preferably 28 to 32%, of at least one block copolymer; - 45 to 65% of a mixture P of (meth)acrylate monomers of which the homopolymer obtained after polymerization has a glass transition temperature of at least 85°C, said mixture P comprising 40 to 60% by weight of a methacrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature of at least 85°C, preferably methyl methacrylate, and 40 to 60% by weight of a mono-acrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature of at least 85°C, preferably isobornyl acrylate or dihydrodicyclopentadienyl acrylate and 0 to 10% by weight, preferably 0 to 5% by weight, of a diacrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature of at least 85°C, preferably TCDDMDA; - 3 to 10%, preferably 4 to 6%, of at least one alkoxysilane (meth)acrylate monomer, preferably trimethosilane methacrylate; - 0.5 to 4%, preferably 1 to 3%, of at least one photoinitiator; - 1 to 16%, preferably 3 to 15%, of methacrylic acid.

[0157] Preferably, the composition comprises (alternatively is made up of), by weight per total weight of the composition: - 28 to 32%, of at least one block copolymer; - 45 to 65% of a mixture P of (meth)acrylate monomers of which rhomopolymer obtained after polymerization at a glass transition temperature of at least 85°C, said mixture P comprising 40 to 60% by weight of methyl methacrylate, and 40 to 60% by weight preferably of isobornyl acrylate and 0 to 5% by weight of TCDDMDA; - 4 to 6% of trimethoxysilane methacrylate, preferably 3-(trimethylsilane)propyl methacrylate; - 1 to 3% of at least one photoinitiator; - 3 to 15% of methacrylic acid. Single-component composition

[0158] Preferably, the composition is a single-component composition, that is to say, a ready-to-use composition. Conversely, preferably, the composition is not a multi-component composition, that is to say, a kit comprising at least two separately packaged components, which components are intended to be mixed together extemporaneously, just before application of the composition thus obtained.

[0159] 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 avoid any premature or unwanted polymerization, the composition must not be exposed to light. Adhesive product

[0160] In a second aspect, the present invention comprises an adhesive product.

[0161] 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).

[0162] 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.

[0163] The container can be chosen, for example, from the group consisting of a bottle or a tube. Adhesive

[0164] In a third aspect, the present invention relates to an adhesive, in particular an adhesive obtained from the photopolymerizable adhesive composition as described above. "Adhesive" or "photopolymerized adhesive composition" refers to the adhesive layer obtained by applying the photopolymerizable adhesive composition, by photopolymerizing it, and optionally by shaping the adhesive thus obtained.

[0165] 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.

[0166] The adhesive can take the form of a film.

[0167] 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).

[0168] 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.

[0169] The adhesive can have a thickness of 10 to 200 µm, preferably 10 to 100 µm, preferably 10 to 30 µm.

[0170] 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).

[0171] Advantageously, the adhesive formulation according to the invention allows the encapsulated object to be used up to at least 70°C, or even up to at least 85°C, for example when the electronic or optoelectronic device is a photovoltaic cell or when the device must meet temperature testing standards (applications in- (for example, cars).

[0172] 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.

[0173] 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.

[0174] 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.

[0175] The adhesive preferably exhibits satisfactory resistance, in particular to aging under ultraviolet radiation, to abrasion and / or to impacts.

[0176] 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%.

[0177] 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

[0178] 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.

[0179] 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 com adhesive photopolymerizable position as described above; and - a second hood.

[0180] The electronic or optoelectronic device may itself comprise a semiconductor layer deposited on a support substrate.

[0181] 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.

[0182] 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.

[0183] 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.

[0184] The module can have a total thickness of 50 to 500 pm, preferably of 50 to 300 pm, preferably of 50 to 150 pm.

[0185] 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 or perovskite photovoltaic cells, organic or perovskite transistors or sensors, or a combination of these devices.

[0186] 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.

[0187] The hoods may be identical or different.

[0188] The hoods can be single-layer or multi-layer.

[0189] The hoods can be flexible or rigid, preferably flexible.

[0190] The module may have an orientation, for example in that it comprises a lower or rear cover (commonly referred to as the "back panel" or "backsheet" in English) and an upper or front cover (commonly referred to as the "front panel" or (frontsheet in English). The upper or anterior cover is preferably transparent and the lower or posterior cover is preferably opaque.

[0191] Depending on the electronic or optoelectronic device used and the desired characteristics and properties of the module, the hoods may have specific properties.

[0192] A hood can be a polymer hood.

[0193] A hood can be an inorganic hood.

[0194] 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 mixtures thereof.

[0195] A polymer hood may include at least one polymer layer obtained from polyethylene terephthalate (PET) (or PET layer) and a fluorinated polymer layer.

[0196] The fluorinated polymer layer, the PET 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.

[0197] A hood may include at least one layer of glass.

[0198] A hood may comprise at least one polymeric layer obtained from po- lymethyl methacrylate (PMMA) (or PMMA layer).

[0199] The glass layer or the PMMA layer is particularly suitable for use as a top or front cover.

[0200] A flexible hood, particularly suitable for encapsulating flexible electronic or optoelectronic devices, especially organic or perovskite cells, 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 of silica, alumina or silicon nitride from 20 to 300 nm, a so-called PSA (pressure sensitive adhesive) film and a fluoropolymer film or layer called a "weathering layer" placed on the exterior to protect the entire environment.

[0201] Method for obtaining the electronic or optoelectronic module

[0202] 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 onto the surface of the device and / or on respective internal surfaces of the first and second covers; - 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.

[0203] The method may also include an ultraviolet-ozone irradiation step of the first hood and / or the second hood before the application step and / or the lamination step.

[0204] In a particular embodiment, the rigid modules are obtained by a vacuum lamination (rolling) technique at temperature (designated “sheet to sheet” in English).

[0205] In a particular embodiment, the flexible modules are obtained by a continuous 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 suited to flexible electronic or optoelectronic devices; preferably devices selected from organic light-emitting diodes, organic or perovskite photovoltaic cells, organic or perovskite transistors and sensors, or a combination of these devices; preferably perovskite-type devices. Applications and uses

[0206] In a sixth aspect, the present invention relates to the use of the photopolymerizable adhesive 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

[0207] The following examples illustrate the invention without limiting it. List of materials and equipment

[0208] Block copolymer: MBM triblock copolymer [polymethyl-methacrylate-poly(styrene-co-butylacrylate)-polymethylmethacrylate block copolymer] (abbreviation: MBM) supplied by Arkema.

[0209] Methacrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature of at least 85°C: methyl methacrylate (abbreviation: MAM)

[0210] Mono-acrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature of at least 85°C: isosomal acrylate (abbreviation: IBOA)

[0211] Acrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature of at least 85°C: tricyclodecanedimethanol diacrylate (abbreviation: TCDDMDA) supplied by Arkema

[0212] Alkoxysilane (meth)acrylate monomers: 3-(trimethoxysilyl)propyl methacrylate. (Silquest® A174 product from Momentive®) (abbreviation: A174)

[0213] Photoinitiators: phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (abbreviation: BAPO) available from Sigma-Aldrich

[0214] Methacrylic acid (abbreviation: AM A)

[0215] Light source: Delolux® 03S UV LED system Modules to test

[0216] The modules to be tested are commonly referred to as test specimens.

[0217] PK layer: perovskite layer of formula Csojo5FAoj95Pb(Ioj88Broji2)3 with a surface area of ​​4x4 cm (16 cm2)

[0218] Glass layer: layer with a surface area of ​​5x5 cm (25 cm2)

[0219] ITO layer: tin-doped indium oxide layer

[0220] The glass layers, ITO, form the supporting substrate as such.

[0221] The PK layers are deposited by the centrifugal coating technique. The The top layer of ITO is deposited by physical vapor deposition.

[0222] The perovskite layers are deposited on the supporting substrate, with an overhang of 5 mm between the edge of the substrate and the perovskite layer.

[0223] 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. Test methods Viscosity measurements

[0224] The viscosity of the compositions was measured according to the standard NF EN 12092 "Adhesives - Determination of viscosity" using a Brookfield DVIII Ultra viscometer (mobile: SC4-27, rotation: 20 revolutions per minute, temperature: 25 °C). Polymerization kinetics and conversion

[0225] The polymerization kinetics and the final conversion rate of the photopolymerizable composition are determined by infrared transform spectroscopy Real-time Fourier transform (RT-FTIR). The composition to be characterized is deposited as a 300 µm thick film between two polypropylene films. The sample is placed in an RT-FTIR spectrophotometer, allowing continuous measurement of the infrared absorption spectrum of the composition during irradiation under the light of a light-emitting diode (LED) lamp with a wavelength of 395 nm and a power of 630 mW / cm². The absorbance measurement at a frequency of 6170 nm, which corresponds to one of the characteristic infrared absorption peaks of the double bond of (meth)acrylate groups, allows monitoring of the monomer conversion rate over time (expressed as a percentage of the number of moles of double bonds that have reacted relative to the number of moles of initial double bonds). After a few tens of seconds, this conversion rate reaches a plateau, which expresses the maximum conversion rate of the composition under these irradiation conditions.The conversion at time t as a percentage (denoted conversion (t)) is calculated by the following relation: conversion (t) = (AO - At) / (A0) x OO with AO and At the absorbance at time t=0 and at the time t considered, respectively.

[0226] From this conversion curve as a function of irradiation time, the efficiency of the polymerization kinetics is evaluated by calculating the propagation constant (kp) and the maximum polymerization rate (Rp). In Table 2, kp.[P«] corresponds to the slope of the curve In ([M0] / [Mt]) as a function of time, with [M0] and [Mt] the concentration of (meth)acrylate groups at time t=0 and at the considered time t, respectively. In this equation, kp corresponds to the propagation rate constant and [P«] the steady-state concentration of propagating radicals. The term Rp / [M0] xlOO corresponds to the maximum slope of the conversion curve versus time. It relates to the maximum polymerization rate. A system will be more efficient in terms of polymerization kinetics the higher the values ​​of kp, [P«] and Rp. Thermal properties and gas barriers

[0227] The thermal properties of the tested modules were analyzed using a differential scanning calorimeter (DSC). Measurements were performed over three cooling-heating cycles from -80 to 200°C at a rate of 10°C per minute. The glass transition temperature was measured during the third heating cycle using the mid-height tangent method, calculated between 40° and 140°C.

[0228] The gas barrier properties were determined by an optical test measuring the degradation kinetics of the perovskite layer of the specimen. 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... A degradation rate algorithmic parameter (cm² / h) is defined. 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), and the article by N. Taheri-makhsousi et al., "A machine vision tool for facilitating the optimization of large area perovskite photovoltaics," npj Computational Materials (2021) 190, the latter article describing the algorithm used in more detail. Photographs of the test specimens are taken regularly, for example, approximately every 48 hours, to assess the aging of the perovskite layers. During these tests, the area of ​​the "active" surface, which is the area of ​​the Perovskite (PK) layer with a thickness greater than an empirical threshold (180nm), knowing that the initial thickness of PK is 400 nm for all tests and that the initial area is on the order of 14 cm2 for all tests, is measured.Monitoring this area allows us to determine the VA parameter (rate of layer degradation in cm2 / h) by means of the linear regression established between 12 and 3 cm2, and the DA12 parameter ([Fig.3]) which is the time after which the "active" surface reaches 12cm2.

[0229] Monitoring the average thickness of the "active" surface allows the VE parameter (thickness degradation rate) obtained by linear regression established between 340 and 230 nm to be determined, and the DE380 parameter, corresponding to the time at which the average thickness, starting from 400 nm, reaches 380 nm. Photopolymerizable adhesive compositions

[0230] 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):

[0231] [Tables 1] MBM MAM IBOA TCDDMD A A174 AMA Viscosity (cP at 25°C) Exl 30 27.5 27.5 0 5 10 6500 CEx A 30 0 55 0 5 10 Nd Ex2 30 27.5 24.75 2.75 5 10 8300 CExB 30 0 52.25 2.75 5 10 Nd CExC 30 55 0 0 5 10 860

[0232] 3g of BAPO photoinitiator were added per 100g of composition mentioned in Table 1.

[0233] Compositions CExA, CExB, and CExC are comparative compositions. Compositions Ex1 and Ex2 according to the invention have viscosity levels compatible with the implementation process, i.e., a viscosity between 200 and 10,000 cP. Compositions CExA and CExB are too viscous to be handled. Results Kinetics and conversion

[0234] Table 2 below summarizes the kinetic and conversion data obtained for the compositions according to the invention (Exl and Ex2) and for the comparative composition (CExC), each of the compositions was tested twice.

[0235] [Tables2] CExC Exl Ex2 kp.[P-] (s >) 0.08 0.32 0.36 0.28 0.37 (Rp / [M]0)xl00 (s1) 5.04 10.2 10.5 9.50 11.3 Max conversion rate (%) 80 80 98 98 98 98 Opacity Transparent

[0236] In Table 2, it can be noted that the Exl and Ex2 formulations have significantly higher polymerization efficiencies, with kp, [P«] and Rp values ​​much higher than those of the reference (CExC). The maximum Conversion Rate is also higher for Exl and Ex2 compared to CexC. Steam barrier

[0237] The degradation rate of multilayer modules obtained with the Exl and Ex2 compositions according to the invention and the comparative composition CExC is tested.

[0238] The modules being tested are photographed at regular intervals. The photographs are taken at 00:00, 159h, 280h, 351h, 447h, 521h, 624h, 737h, 852h, 948h and 1091h.

[0239] Several parameters are extracted from these images, which are: • Area of ​​the “active” surface ([Fig.l]) which is the area of ​​Perovskite layer (PK) with a thickness greater than an empirical threshold (180nm) knowing that the initial thickness of PK is 400 nm for all tests and that initial Faire is on the order of 14 cm2 for all tests. • Monitoring this area allows us to determine the VA parameter (Figure 2) through linear regression established between 12 and 3 cm2. We observe that the VA parameter is similar for the 3 formulations. • This same area monitoring allows us to define the parameter DA12 (figure 3) which is the time after which the "active" surface reaches 12cm2. We observe that DA12 is similar for the formulations. • Monitoring of the average thickness of the "active" surface ([Fig.4]): • the VE parameter (figure 5) obtained by the linear regression established between 340 and 230 nm. It can be seen that VE is better for the compositions according to the invention. • The DE380 parameter (Figure 6), corresponding to the time it takes for the average thickness, starting from 400 nm, to reach 380 nm, shows that the 3 formulations have very close values. Shrinkage

[0240] The linear shrinkage upon polymerization of the three example formulas was measured. This measurement was performed by photorheology using a Thermofischer Haake Mars 40 plane / plane instrument, monitoring in real time the thickness (denoted h) of the sample in the rheometer gap under irradiation with a 286 MW / cm² mercury UV lamp, at a shear rate of 0.01%. The temperature was stabilized at 25°C for 120 s before the start of the measurement. The shrinkage was then calculated as the percentage contraction of the term h. The results are given in Table 3 below.

[0241] [Tables3] CExC Exl Ex2 Withdrawal (%) 9.7 8.7 4

[0242] The compositions of the invention therefore allow a significant reduction in shrinkage.

Claims

Claims

1. A photopolymerizable adhesive composition comprising, by weight per total weight of the photopolymerizable adhesive composition: from 20 to 35% of at least one block copolymer, preferably a (meth)acrylic block copolymer; from 45 to 75% of a mixture P of (meth)acrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature (Tg) of at least 85°C, said mixture P comprising at least one methacrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature (Tg) of at least 85°C and at least 5% by weight of a mono-acrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature (Tg) of at least 85°C; from 2 to 15% of at least one alkoxysilane (meth)acrylate monomer; and from 0.1 to 5% of at least one photoinitiator.

2. Adhesive photopolymerizable composition according to claim 1, wherein 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 (Tg) is less than 20°C.

3. Photopolymerizable adhesive composition, according to one of the preceding claims, according to which the mixture P comprises at least one methacrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature of at least 85°C chosen from the group consisting of methyl methacrylate, tert-butyl methacrylate, phenyl methacrylate, isopropyl methacrylate, isobornyl methacrylate, cyclohexyl methacrylate, 4-tert-butylcyclohexyl methacrylate, and mixtures thereof, preferably the methacrylate monomer is methyl methacrylate; and at least 5% by weight relative to the total weight of the mixture P of an acrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature (Tg) of at least 85°C chosen from isobornyl acrylate, dihydrodicyclopentadienyl acrylate, and their mixtures, preferably the acrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature (Tg) of at least 85°C is isobornyl acrylate.

4. Adhesive photopolymerizable composition according to one of the preceding claims, in which the mixture P further comprises at least one diacrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature (Tg) of at least 85°C, preferably said diacrylate monomer is chosen from dipropylene glycol diacrylate, neopentylglycolhydroxypivalate diacrylate, tricyclodecanedimethanol diacrylate, preferably the diacrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature of at least 85°C is tricyclodecanedimethanol diacrylate (TCDDMDA).

5. Photopolymerizable adhesive composition, according to one of the preceding claims, in which the mixture P comprises: - from 20% to 95% by weight, more preferably from 20% to 80% by weight, and even more preferably from 30% to 70%, preferably from 40 to 60%, by weight relative to the weight of mixture P, of at least one methacrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature (Tg) of at least 85°C; - at least 5%, preferably at least 10%, more preferably from 5 to 80%, more preferably from 20% to 80%, even more preferably from 30% to 70%, preferably from 40 to 60% by weight of a mono-acrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature (Tg) of at least 85°C;and from 1 to 20% by weight, more preferably from 1 to 10% by weight, preferably from 1 to 5% by weight, of at least one diacrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature of at least 85°C.;

6. Photopolymerizable adhesive composition according to one of the preceding claims, according to which the alkoxysilane (meth)acrylate monomer is chosen from the group consisting of trialkoxysilane (meth)acrylate monomers.

7. A composition according to any preceding claim comprising, preferably consisting of, by weight per total weight of the composition: - from 25 to 35%, preferably from 28 to 32%, of at least one block copolymer; - from 45 to 65%, of a mixture P of (meth)acrylate monomers whose homopolymer obtained after polymerization has a glass transition temperature of at least 85°C, said mixture P comprising from 40 to 60% by weight of a methacrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature of at least 85°C, preferably methyl methacrylate, and from 40 to 60% by weight of a mono-acrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature of at least 85°C, preferably isobornyl acrylate or dihydrodicyclopentadienyl acrylate and from 0 to 10% by weight, preferably from 0 to 5% by weight, of a diacrylate monomer whose homopolymer obtained after polymerization has a glass transition temperature of at least 85°C, preferably TCDDMDA; - from 3 to 10%, preferably from 4 to 6%, of at least one alkoxysilane (meth)acrylate monomer, preferably trimethoxysilane methacrylate; - from 0.5 to 4%, preferably from 1 to 3%, of at least one photoinitiator; - from 1 to 16%, preferably from 3 to 15%, of methacrylic acid.

8. A composition according to any preceding claim comprising, preferably consisting of, by weight per total weight of the composition: - from 28 to 32% of at least one block copolymer; - from 45 to 65%, of a mixture P of (meth)acrylate monomers the homopolymer of which obtained after polymerization has a glass transition temperature of at least 85°C, said mixture P comprising from 40 to 60% by weight of methyl methacrylate, and from 40 to 60% by weight preferably of isobornyl acrylate and from 0 to 5% by weight of TCDDMDA; - 4 to 6%, trimethoxysilane methacrylate; - from 1 to 3%, of at least one photoinitiator; - from 3 to 15%, of methacrylic acid.

9. Photopolymerizable adhesive composition, according to one of the preceding claims, in that it is a single-component composition.

10. A photopolymerizable adhesive composition according to any one of the preceding claims, in that it has a glass transition temperature after polymerization of at least 85°C, preferably at least 90°C, more preferably at least 100°C.

11. An adhesive product comprising the photopolymerizable adhesive composition according to one of the preceding claims and an opaque container containing it.

12. Adhesive obtained by the method comprising the following steps: application of a photopolymerizable adhesive composition according to one of claims 1 to 10 on at least one cover and / or one electronic or optoelectronic device; photopolymerization of the applied photopolymerizable adhesive composition to obtain a polymerized adhesive; and optionally shaping of the polymerized adhesive.

13. Electronic or optoelectronic module comprising the assembly of a series of layers comprising, in this order: a first cover; a first adhesive according to claim 12 or obtained from the photopolymerizable adhesive composition according to one of claims 1 to 10; a flexible electronic or optoelectronic device; a second adhesive according to claim 12 or obtained from the photopolymerizable adhesive composition according to one of claims 1 to 10; and a second cover.

14. Electronic or optoelectronic module, according to claim 13, according to which the flexible electronic or optoelectronic device is chosen from organic light-emitting diodes, organic photovoltaic cells, organic transistors, or organic sensors, or a combination of these devices.

15. Electronic or optoelectronic module, according to one of claims 13 or 14, according to which the electronic or optoelectronic device- Flexible tronics is a perovskite type device.

16. Method for obtaining the module according to one of claims 13 to 15, the method comprising the following steps: providing an electronic or optoelectronic device; providing an adhesive photopolymerizable composition according to one of claims 1 to 10; the supply of a first hood; the provision of a second hood; 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 inner surfaces of the first and second covers; and photopolymerization of layers of adhesive photopolymerizable composition.

17. Use of the photopolymerizable adhesive composition according to one of claims 1 to 10, or of the adhesive according to claim 11 or 12, for the encapsulation of flexible electronic or optoelectronic devices.