Composition photoréticulable

Abstract

The invention relates to a photocrosslinkable composition comprising: - a monofunctional (meth)acrylate monomer, - a functionalized core-shell filler, - a (meth)acrylate polymer, preferably a (meth)acrylate oligomer, chosen from urethane (meth)acrylate polymers, polyester (meth)acrylate polymers, epoxy (meth)acrylate polymers, and mixtures thereof, and - a photoinitiator. The present invention also relates to the use of the composition according to the invention as an adhesive, coating, UV ink or in 3D printing. The present invention also relates to a method for assembling substrates comprising: - coating, on at least one surface of the substrates to be assembled, the composition according to the invention, then - bringing the substrates into contact, then - crosslinking the composition. Finally, the present invention relates to an article comprising the composition according to the invention, said composition binding at least two substrates of said article. Figure for abstract: none.

Description

Title of the invention: Photocrosslinkable composition Field of invention

[0001] The present invention relates to a photocrosslinkable composition and its use, a method of assembling substrates and an article. Technical background

[0002] Acrylic compositions are known reactive systems crosslinking by radical polymerization.

[0003] Compositions whose polymerization is initiated by exposure of the composition to light are called "photopolymerizable" or "photocrosslinkable". The monomers constituting the matrix are generally intended to form thermosetting polymers, by crosslinking the polymer chains. Such compositions allow rapid and complete polymerization by simple exposure to light, in particular UV, making them very simple to implement. In addition, they can be formulated in single-component form, which allows significant time savings compared to two-component compositions (the latter requiring in particular a preliminary step of mixing the two components before application).

[0004] However, photocrosslinkable acrylic compositions, in particular the polymer network obtained after crosslinking by exposure to light, generally have mechanical properties, in particular the adhesion strength and in particular the shear strength, which are inferior to those of two-component acrylic compositions whose polymerization is initiated by a redox system. They may therefore prove unsuitable for certain industrial applications.

[0005] There is therefore a need to provide a photocrosslinkable acrylic composition having improved adhesion strength, in particular shear strength.

[0006] Furthermore, it would be advantageous to provide a photocrosslinkable acrylic composition having transparency properties, so that it does not prevent the passage of light when applied to transparent substrates. Summary of the invention

[0007] The present invention relates to a photocrosslinkable composition comprising:

[0008] - a monofunctional (meth)acrylate monomer,

[0009] - a functionalized core-shell charge,

[0010] - a (meth)acrylate polymer, preferably a (meth)acrylate oligomer, chosen among urethane (meth)acrylate polymers, polyester (meth)acrylate polymers, epoxy (meth)acrylate polymers, and mixtures thereof, and

[0011] - a photoinitiator.

[0012] The present invention also relates to the use of the composition according to the invention as an adhesive, coating, UV ink or in 3D printing, preferably as an adhesive.

[0013] The present invention also relates to a method for assembling substrates comprising:

[0014] - coating, on at least one surface of the substrates to be assembled, the composition according to the invention, then

[0015] - bringing the substrates into contact, then

[0016] - crosslinking of the composition.

[0017] Finally, the present invention relates to an article comprising the composition according to the invention, said composition binding at least two substrates of said article.

[0018] The present invention makes it possible to meet one or more of the needs mentioned above. In particular, the composition according to the invention has improved shear strength. Description of the invention Composition

[0019] The composition according to the invention is photocrosslinkable, that is to say that the crosslinking of the composition is triggered by exposure to electromagnetic radiation, preferably ultraviolet (UV) radiation. Monofunctional (meth)acrylate monomer

[0020] The composition according to the invention comprises a monofunctional (meth)acrylate monomer, that is to say a monomer comprising exactly one (meth)acrylate group.

[0021] In this text, and unless otherwise stated (such as “exactly one”), “one” means one or more.

[0022] In this text, the term “(meth)acrylate” means methacrylate or acrylate.

[0023] Advantageously, the monofunctional (meth)acrylate monomer is of formula (I): CH2=C(Ra)-COORb, in which:

[0024] - Ra represents a hydrogen atom or a methyl group, preferably a hydrogen atom,

[0025] - Rb represents an aliphatic or aromatic hydrocarbon group comprising optionally one or more groups chosen from ether, ester, hydroxyl, carbonyl, and mixtures thereof, preferably Rb represents an aliphatic or aromatic hydrocarbon group (not comprising a heteroatom), more preferably an alkyl group.

[0026] In the present text, the term “alkyl” means an acyclic or cyclic aliphatic hydrocarbon group (i.e. comprising an aliphatic cycle), not comprising a carbon-carbon double bond.

[0027] When Rb represents an alkyl group, the monofunctional (meth)acrylate monomer may be chosen from C1-C22 alkyl (meth)acrylates, preferably C1-C18 alkyl (meth)acrylates, more preferably C8-C15 alkyl (meth)acrylates.

[0028] In the present text, the term “CX-CY alkyl (meth)acrylate” means an alkyl ester of (meth)acrylic acid in which the alkyl contains from X to Y carbon atoms.

[0029] In this text, the term “(meth)acrylic acid” means methacrylic acid or acrylic acid.

[0030] For example, the monofunctional (meth)acrylate monomer may be selected from methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, iso-propyl (meth)acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-octyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, n-decyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, hexadecyl (meth)acrylate, octadecyl (meth)acrylate, tricyclodecanemethanol (meth)acrylate, isobornyl (meth)acrylate, 3,3,5-trimethylcyclohexyl (meth)acrylate, tert-butylcyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate (CAS 7398-56-3), (octahydro-4,7-methano-1H-indenyl)methyl (meth)acrylate (CAS 127823-21-6), benzyl (meth)acrylate optionally ethoxylated (i.e. comprising at least one -O-(CH2CH2O)n- group, in which n is different from 0),2-(2-ethoxyethoxy)ethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, and mixtures thereof, preferably from isobornyl (meth)acrylate, 3,3,5-trimethylcyclohexyl (meth)acrylate, tert-butylcyclohexyl (meth)acrylate, (octahydro-4,7-methano- lH-indenyl)methyl (meth)acrylate, n-octyl (meth)acrylate, n-decyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, hexadecyl (meth)acrylate, octadecyl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, and mixtures thereof, more preferably from isobornyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, tert-butylcyclohexyl acrylate, (octahydro-4,7-methano-1H-indenyl)methyl acrylate, n-octyl acrylate, n-decyl acrylate, dodecyl acrylate, tridecyl acrylate, tetradecyl acrylate, hexadecyl acrylate, octadecyl acrylate, 2-(2-ethoxyethoxy)ethyl acrylate, tetrahydrofurfuryl acrylate,and mixtures thereof, in particular a mixture of isobornyl acrylate and another monomer chosen from dodecyl acrylate, tridecyl acrylate, and their mixture, optionally with 2-(2-ethoxyethoxy)ethyl acrylate.,

[0031] Advantageously, the monofunctional (meth)acrylate monomer comprises at least 40% by weight of a cyclic alkyl acrylate (preferably isobornyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, tert-butylcyclohexyl acrylate and / or (octahydro-4,7-methano-1H-indenyl)methyl acrylate), relative to the total weight of the monofunctional (meth)acrylate monomer, preferably at least 50% by weight, more preferably at least 60% by weight. Preferably, the monofunctional (meth)acrylate monomer comprises at least 40% by weight of isobornyl acrylate relative to the total weight of the monofunctional (meth)acrylate monomer, preferably at least 50% by weight, more preferably at least 60% by weight.

[0032] According to one embodiment, the monofunctional (meth)acrylate monomer comprises a cyclic alkyl acrylate and an acyclic alkyl acrylate.

[0033] Preferably, the monofunctional (meth)acrylate monomer comprises:

[0034] - at least 40% by weight, relative to the total weight of the (meth)acrylate monomer monofunctional, preferably at least 50% by weight, more preferably at least 60% by weight, of a cyclic alkyl acrylate, preferably isobornyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, tert-butylcyclohexyl acrylate and / or (octahydro-4,7-methano-1H-indenyl)methyl acrylate, more preferably isobornyl acrylate, and

[0035] - between 1% and 60% by weight, relative to the total weight of the (meth)acrylate monomer monofunctional, preferably between 5% and 50% by weight, more preferably between 10% and 40% by weight, of an acyclic alkyl acrylate, preferably n-octyl acrylate, n-decyl acrylate, dodecyl acrylate, tridecyl acrylate, tetradecyl acrylate, hexadecyl acrylate and / or octadecyl acrylate, in particular dodecyl acrylate and / or tridecyl acrylate.

[0036] The content of monofunctional (meth)acrylate monomer may be between 20% and 80% by weight relative to the total weight of the composition according to the invention, preferably between 30% and 70% by weight, more preferably between 40% and 60% by weight.

[0037] In the context of the invention, the ranges of values ​​are understood to include the limits. For example, the range “between 0% and 25%” includes in particular the values ​​0% and 25%. Functionalized core-bark filler

[0038] The composition according to the invention comprises a functionalized core-shell filler.

[0039] Core-shell fillers may be generally described as polymeric substances, typically in the form of particles, comprising a core (inner part) comprising (or consisting essentially of) a core polymer and a shell (outer part) comprising (or consisting essentially of) a shell polymer. One or more intermediate polymer layers may be included between the core and shell polymers. By "consisting essentially" is meant that the core (or shell) advantageously comprises less than 5% by weight of compounds other than the core (or shell) polymer relative to the total weight of the core (or shell), preferably less than 2% by weight, more preferably less than 1% by weight.

[0040] Generally, the shell polymer has a glass transition temperature higher than that of the core polymer. The glass transition temperature of the core-shell filler polymers can be measured in accordance with ISO 11357-2, for example with a heating rate of 20°C / min. Generally, the glass transition temperature of the core polymer is less than 10°C, preferably less than 0°C, more preferably less than -20°C. Generally, the glass transition temperature of the shell polymer is greater than 60°C, preferably greater than 80°C, more preferably greater than 100°C.

[0041] Unless otherwise indicated, the standards referred to throughout the application are those in effect on the date of filing of the application.

[0042] The core polymer may comprise a polymer (homopolymer and / or copolymer) of a conjugated diene comprising from 4 to 12, preferably from 4 to 8, carbon atoms (such as isoprene and / or butadiene), and / or a polymer (homopolymer and / or copolymer) of an acyclic alkyl (meth)acrylate in which the alkyl chain (linear or branched) comprises from 1 to 12, preferably from 1 to 8, carbon atoms (such as butyl acrylate).

[0043] Advantageously, the core polymer comprises (or consists essentially of) a polymer of a conjugated diene chosen from isoprene, butadiene, and mixtures thereof, preferably butadiene. Preferably, the core polymer comprises (or consists essentially of) an isoprene homopolymer, a butadiene homopolymer, an isoprene-butadiene copolymer, a butadiene-styrene copolymer and / or an isoprene-styrene copolymer, more preferably a butadiene homopolymer.

[0044] By "consisting essentially" is meant that the core polymer advantageously comprises less than 5% by weight of polymer(s) other than the polymers mentioned above relative to the total weight of the core polymer, preferably less than 2% by weight, more preferably less than 1% by weight.

[0045] The core polymer may be crosslinked. The crosslinking agent(s) / monomer(s) may be selected from polyfunctional vinylaromatic compounds such as divinylbenzene and divinyltoluene, polyhydric alcohols such as ethylene glycol di(meth)acrylate and 1,3-butanediol di(meth)acrylate, tri(meth)acrylates, allyl carboxylates such as allyl acrylate and allyl methacrylate, and di- and triallyl compounds such as diallyl phthalate, diallyl sebacate and triallyl triazine.

[0046] The bark polymer may comprise a polymer (homopolymer and / or copolymer) of an acyclic alkyl (meth)acrylate in which the alkyl chain (linear or branched) comprises from 1 to 12 carbon atoms, preferably from 1 to 8 carbon atoms. carbon, more preferably from 1 to 4 carbon atoms, such as methyl methacrylate.

[0047] When one or more intermediate polymer layers are present, each intermediate polymer may comprise a polymer (homopolymer and / or copolymer) of an acyclic alkyl (meth)acrylate in which the alkyl chain (linear or branched) comprises from 1 to 12 carbon atoms, preferably from 1 to 8 carbon atoms, more preferably from 1 to 4 carbon atoms, such as methyl methacrylate. Each intermediate polymer may be the same as or different from the shell polymer.

[0048] The core-shell filler is “functionalized” because at least one of the shell polymer and the optional intermediate polymer(s) comprises functional groups different from the groups derived from the polymerization of an acyclic alkyl (meth)acrylate (i.e., different from the acyclic alkyl esters remaining after polymerization of said alkyl (meth)acrylate).These functional groups may be selected from epoxy groups (such as the glycidyl group), carboxylic acid groups, carboxamide groups (preferably N,N-dialkylcarboxamide groups), alkoxy groups (such as methoxy, ethoxy), amine groups (e.g. primary amine), cycloalkyl ester groups (preferably C8-C12 cycloalkyl such as isobutyl, 3,3,5-trimethylcyclohexyl, tert-butylcyclohexyl and / or (octahydro-4,7-methano-1H-indenyl)methyl ester), and mixtures thereof, preferably from carboxamide groups, cycloalkyl ester groups, and mixtures thereof, more preferably from cycloalkyl ester groups.Preferably, the functional group is derived from a functional (meth)acrylate; for example, it may be introduced by grafting the polymer to be functionalized (shell polymer, intermediate polymer(s)) with a functional (meth)acrylate or by introducing a functional (meth)acrylate during the polymerization of the polymer to be functionalized.Said functional (meth)acrylate may be chosen from glycidyl (meth)acrylate, (meth)acrylic acid, (meth)acrylic acid amides, 2-methoxyethyl (meth)acrylate, (meth)acrylates comprising a primary amine (such as 2-aminoethyl (meth)acrylate), cycloalkyl (meth)acrylates, and mixtures thereof, preferably from (meth)acrylic acid amides, cycloalkyl (meth)acrylates, and mixtures thereof, more preferably from N,N-dialkylamides of (meth)acrylic acid (such as dimethylacrylamide), C8-C12 cycloalkyl (meth)acrylates (such as isobornyl (meth)acrylate, 3,3,5-trimethylcyclohexyl (meth)acrylate, tert-butylcyclohexyl (meth)acrylate and / or (octahydro-4,7-methano-1H-indenyl)methyl), and mixtures thereof, even more preferably C8-C12 cycloalkyl (meth)acrylates, in particular isocarboxylic (meth)acrylate.

[0049] According to a first embodiment, the core-shell filler does not comprise an intermediate polymer. According to this embodiment, the shell polymer comprises (or consists essentially of) a copolymer of an acyclic alkyl (meth)acrylate and a functional (meth)acrylate. Advantageously, the acyclic alkyl (meth)acrylate is chosen from methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, and mixtures thereof, preferably methyl methacrylate.The functional (meth)acrylate may be as described above, preferably chosen from (meth)acrylic acid amides, cycloalkyl (meth)acrylates, and mixtures thereof, more preferably from (meth)acrylic acid N,N-dialkylamides (such as dimethylacrylamide), C8-C12 cycloalkyl (meth)acrylates (such as isobutyl, 3,3,5-trimethylcyclohexyl, tert-butylcyclohexyl and / or (octahydro-4,7-methano-1H-indenyl)methyl (meth)acrylate), and mixtures thereof, even more preferably C8-C12 cycloalkyl (meth)acrylates, in particular isobutyl (meth)acrylate.

[0050] In particular, the bark polymer comprises (or consists essentially of) a copolymer comprising at least 70% by weight of repeating units derived from methyl methacrylate relative to the total weight of said copolymer.

[0051] By "consisting essentially" is meant that the bark polymer advantageously comprises less than 5% by weight of polymer(s) other than the aforementioned copolymer relative to the total weight of the bark polymer, preferably less than 2% by weight, more preferably less than 1% by weight.

[0052] The shell polymer may be crosslinked, preferably is crosslinked. The crosslinking agent(s) / monomer(s) may be selected from polyfunctional vinylaromatic compounds such as divinylbenzene and divinyltoluene, polyhydric alcohols such as ethylene glycol di(meth)acrylate and 1,3-butanediol di(meth)acrylate, tri(meth)acrylates, allyl carboxylates such as allyl acrylate and allyl methacrylate, and di- and triallyl compounds such as diallyl phthalate, diallyl sebacate and triallyl triazine.

[0053] According to a second embodiment, the core-shell filler comprises an intermediate polymer. According to this embodiment, at least one of the shell polymer and the intermediate polymer(s) comprises (or consists essentially of) a copolymer of an acyclic alkyl (meth)acrylate and a functional (meth)acrylate. Advantageously, the acyclic alkyl (meth)acrylate is chosen from methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, and mixtures thereof, preferably methyl methacrylate. The functional (meth)acrylate may be as described above, preferably chosen from amides of the acid (meth)acrylic acid, cycloalkyl (meth)acrylates, and mixtures thereof, more preferably among N,N-dialkylamides of (meth)acrylic acid (such as dimethylacrylamide), C8-C12 cycloalkyl (meth)acrylates (such as isobornyl, 3,3,5-trimethylcyclohexyl, tert-butylcyclohexyl and / or (octahydro-4,7-methano-1H-indenyl)methyl (meth)acrylate), and mixtures thereof, even more preferably C8-C12 cycloalkyl (meth)acrylates, in particular isobornyl (meth)acrylate.

[0054] In particular, the bark polymer and the intermediate polymer(s) comprise (or consist essentially of) a polymer comprising at least 70% by weight of repeating units derived from methyl methacrylate relative to the total weight of said polymer.

[0055] By "consisting essentially" is meant that the bark polymer and the intermediate polymer(s) advantageously comprise less than 5% by weight of polymer(s) other than the aforementioned polymer relative to the total weight of said bark polymer / intermediate, preferably less than 2% by weight, more preferably less than 1% by weight.

[0056] Each of the shell polymers and intermediate(s) may be crosslinked. Preferably, the intermediate polymer is crosslinked. The crosslinking agent(s) / monomer(s) may be selected from polyfunctional vinylaromatic compounds such as divinylbenzene and divinyltoluene, polyhydric alcohols such as ethylene glycol di(meth)acrylate and 1,3-butanediol di(meth)acrylate, tri(meth)acrylates, allyl carboxylates such as allyl acrylate and allyl methacrylate, and di- and triallyl compounds such as diallyl phthalate, diallyl sebacate and triallyl triazine.

[0057] According to a preferred embodiment, the functionalized core-shell filler comprises:

[0058] - a core comprising (or consisting essentially of) a core polymer comprising (or consisting essentially of) a homopolymer of butadiene,

[0059] - a bark comprising (or consisting essentially of) a bark polymer comprising (or consisting essentially of) a methyl methacrylate polymer, in particular comprising at least 70% by weight of repeating units derived from methyl methacrylate relative to the total weight of said polymer, and

[0060] - optionally one or more layers of intermediate polymer, each layer comprising (or consisting essentially of) an intermediate polymer comprising (or consisting essentially of) a methyl methacrylate polymer, in particular comprising at least 70% by weight of repeating units derived from methyl methacrylate relative to the total weight of said polymer,

[0061] wherein at least one of the bark polymer and the inter polymer(s) optional mediator(s) comprises carboxamide and / or cycloalkyl ester groups, preferably C8-C12 cycloalkyl ester groups, in particular isobornyl, 3,3,5-trimethylcyclohexyl, tert-butylcyclohexyl and / or (octahydro-4,7-methano-1H-indenyl)methyl ester groups, in particular isobornyl.

[0062] The volume average diameter of the functionalized core-shell filler may be between 10 and 900 nm, preferably between 20 and 700 nm, more preferably between 20 and 500 nm. The volume average diameter may be measured by dynamic light scattering (DLS).

[0063] The content of functionalized core-shell filler may be between 1% and 30% by weight relative to the total weight of the composition according to the invention, preferably between 2% and 20% by weight, more preferably between 3% and 10% by weight. (Meth)acrylate polymer

[0064] The composition according to the invention comprises a (meth)acrylate polymer chosen from urethane (meth)acrylate polymers, polyester (meth)acrylate polymers, epoxy (meth)acrylate polymers, and mixtures thereof, preferably from urethane (meth)acrylate polymers. Preferably, the (meth)acrylate polymer is a (meth)acrylate oligomer chosen from urethane (meth)acrylate oligomers, polyester (meth)acrylate oligomers, epoxy (meth)acrylate oligomers, and mixtures thereof, more preferably from urethane (meth)acrylate oligomers.

[0065] The term “oligomer” is known to those skilled in the art and can be defined as a small polymer, for example comprising from 2 to 30 repeating units.

[0066] Advantageously, the (meth)acrylate polymer comprises between two and six (meth)acrylate groups, preferably exactly two (meth)acrylate groups. Preferably, the (meth)acrylate polymer is an acrylate polymer.

[0067] The (meth)acrylate polymer may have a number average molecular weight of between 500 g / mol and 20000 g / mol, preferably between 700 g / mol and 10000 g / mol, for example between 800 g / mol and 6500 g / mol. The number average molecular weight may be determined by size exclusion chromatography (SEC), for example using polymethyl (meth)acrylate reference standards and tetrahydrofuran as solvent.

[0068] The (meth)acrylate polymer may have a glass transition temperature (Tg) of less than 30°C, preferably less than 0°C, for example between -60°C and -5°C. The Tg may be determined by dynamic mechanical analysis (DMA).

[0069] There are many (meth)acrylate polymers commercially available, notably from SARTOMER. • Urethane (meth)acrylate polymer

[0070] The urethane (meth)acrylate polymer can be obtained by reaction between a polyol, preferably a diol, and a polyisocyanate, preferably a diisocyanate, thus forming one or more urethane bonds (-OC(=O)-NH-), followed by functionalization with a (meth)acrylate.

[0071] The polyol may be aliphatic or aromatic, preferably aliphatic. The polyol may be a polyether polyol (such as polyethylene glycol, polypropylene glycol) and / or a polyester polyol, preferably a polyester polyol.

[0072] The polyisocyanate may be aliphatic or aromatic, preferably aliphatic.

[0073] The (meth)acrylate used for the functionalization may be a hydroxyalkyl (meth)acrylate, for example hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxypentyl (meth)acrylate and / or hydroxyhexyl (meth)acrylate. Said (meth)acrylate is preferably an acrylate. • Polyester (meth)acrylate polymer

[0074] The polyester (meth)acrylate polymer can be obtained by reaction between a polycarboxylic acid, preferably dicarboxylic acid, and a polyol, preferably diol, thereby forming a polyester polyol, preferably polyester diol, having several ester bonds, followed by esterification with (meth)acrylic acid.

[0075] The polyester polyol may be aliphatic or aromatic, preferably aliphatic. • Epoxy (meth)acrylate polymer

[0076] The epoxy (meth)acrylate polymer can be obtained by (meth)acrylation of a polyepoxidized polymer, preferably diepoxidized.

[0077] The polyepoxidized polymer may be aliphatic or aromatic, preferably aliphatic.

[0078] For example, the polyepoxidized polymer may be polyepoxidized polybutadiene and / or a polyepoxidized polyunsaturated oil.

[0079] The content of (meth)acrylate polymer may be between 5% and 50% by weight relative to the total weight of the composition according to the invention, preferably between 6% and 40% by weight, more preferably between 7% and 30% by weight. Photoinitiator

[0080] The composition according to the invention comprises a photoinitiator which makes it possible to generate, by exposure to electromagnetic radiation (preferably UV), radicals which will be responsible for initiating the photocrosslinking reaction. This is of course chosen according to the radiation source used, depending on its capacity to effectively absorb the selected radiation.

[0081] Advantageously, the photoinitiator is suitable for working with irradiation sources emitting in the UV-visible region (in particular with a wavelength between 100 nm and 800 nm). For example, the source of the UV-visible radiation may be an LED or broad-spectrum lamp centered on UVA (wavelength range between 315 nm and 400 nm) of iron-doped mercury type.

[0082] The photoinitiator may be selected from the group consisting of type I, type II photoinitiators, and mixtures thereof, preferably type I photoinitiators. Type I and II photoinitiators are known to those skilled in the art. In particular, type I photoinitiators undergo unimolecular bond cleavage upon irradiation to produce free radicals, while type II photoinitiators undergo a bimolecular reaction where the excited state of the photoinitiator interacts with a second molecule (a co-initiator) to generate free radicals. • Type I photoinitiator

[0083] The type I photoinitiator can be chosen from:

[0084] - acetophenone,

[0085] - alkoxyacetophenones (such as 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, 4'-ethoxyacetophenone), preferably a-dialkoxyacetophenones,

[0086] - hydroxyalkylphenones (such as 3'-hydroxyacetophenone, 4'-hydroxyacetophenone, 2,2-dimethyl-2-hydroxyacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, 2-hydroxy-2-methylpropiophenone), preferably α-hydroxyalkylphenones,

[0087] - aminoalkylphenones (such as 2-methyl-4'-(methylthio)-2-morpholino-propiophenone, 2-benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone, 2-(4-(methylbenzyl)-2-dimethylamino-l-(4-morpholinophenyl)-l-butanone), preferably α-aminoalkylphenones,

[0088] - benzoin ethers (such as benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether),

[0089] - phosphine oxides (such as diphenyl oxide- (2,4,6-trimethylbenzoyl)phosphine (TPO), ethyl-(2,4,6-trimethylbenzoyl)phenylphosphinate (TPO-L, CAS: 84434-11-7), phenylbis-(2,4,6-trimethylbenzoyl)phosphine oxide (BAPO, CAS: 162881-26-7), preferably acylphosphine oxides,

[0090] - metallocenes (such as ferrocene, bis[2,6-difluoro-3-(l / / - pyrrol-l-yl)phenyl]titanocene, iron(II)(cumene)cyclopentadienyl hexafluorophosphate),

[0091] - benzil and its derivatives (such as 4,4'-dimethylbenzil),

[0092] - and mixtures thereof.

[0093] Advantageously, the type I photoinitiator is chosen from α-hydroxyalkylphenones, acylphosphine oxides, and mixtures thereof, in particular is a mixture of photoinitiators selected from hydroxyalkylphenones and acylphosphine oxides. • Type II photoinitiator

[0094] The type II photoinitiator can be chosen from:

[0095] - benzophenones (such as benzophenone, 4-phenylbenzophenone, 4-(4-methylphenylthio)benzophenone, 1 - [4[(4-benzoylphenyl)thio]phenyl] -2-methyl-2-[(4-methylphenyl)sulfonyl] -1 -propano ne (CAS: 272460-97-6)),

[0096] - thioxanthones (such as risopropylthioxanthone (ITX), 2,4-diethylthioxanthone, 2,4-dimethylthioxantone, 2-chlorothioxanthone, 1-chloro-4-isopropylthioxanthone),

[0097] - phenylglyoxylic acid esters (such as methyl phenylglyoxylate),

[0098] - dibenzylidene ketones (such as l,5-bis[4-(dimethy lamino)pheny 1] -1,4-pentadien- 3 -one),

[0099] - coumarins (such as coumarin, 7-methoxycoumarin, 7-diethylaminocoumarin),

[0100] - and mixtures thereof.

[0101] The photoinitiator content may be between 0.1% and 5% by weight relative to the total weight of the composition according to the invention, preferably between 0.5% and 4% by weight, more preferably between 0.8% and 3% by weight. Membership Promoter

[0102] Advantageously, the composition according to the invention further comprises an adhesion promoter.

[0103] The adhesion promoter may be chosen from silanes (such as aminosilanes, epoxysilanes, acryloyl silanes), adhesion promoters based on a phosphate ester (such as mono-, di- and triesters of 2-hydroxyethyl (meth)acrylate phosphate), (meth)acrylic acid, (meth)acrylic acid amides (preferably N,N-dialkylamides of (meth)acrylic acid such as N,N-dimethylacrylamide), metal di(meth)acrylates (such as zinc di(meth)acrylate, calcium di(meth)acrylate, magnesium di(meth)acrylate), and mixtures thereof, preferably from (meth)acrylic acid, N,N-dialkylamides of (meth)acrylic acid, and mixtures thereof, in particular a mixture of acrylic acid, methacrylic acid and of N,N-dimethylacrylamide.

[0104] Advantageously, the adhesion promoter comprises at least 60% by weight of (meth)acrylic acid amide (in particular N,N-dimethylacrylamide) relative to the total weight of the adhesion promoter, preferably at least 70% by weight, more preferably at least 80% by weight.

[0105] The content of adhesion promoter may be between 5% and 25% by weight relative to the total weight of the composition according to the invention, preferably between 10% and 20% by weight, more preferably between 12% and 18% by weight. Acrylic block copolymer

[0106] The composition according to the invention may further comprise an acrylic block copolymer.

[0107] By "acrylic block copolymer" is meant a block copolymer comprising at least one acrylic block, i.e. comprising at least one block consisting of a polymer obtained from at least one acrylic monomer. By "acrylic monomer" is meant in particular a monomer comprising a group of formula -X-(C=O)-C(R)=CH2, in which R represents a hydrogen atom or a methyl radical, and -X- represents -O- or -NR'- with R' representing a hydrogen atom or an alkyl radical (cyclic, linear or branched) comprising from 1 to 22 carbon atoms, preferably from 1 to 14, more preferably from 1 to 8. Preferably, -X- represents -O-.

[0108] By "block copolymer" is meant a copolymer comprising polymer blocks, i.e. polymer sequences chemically different from each other and linked together by a covalent bond.

[0109] Advantageously, the acrylic block copolymer is not obtained from styrene, preferably the acrylic block copolymer comprises only (meth)acrylic blocks (i.e. all its blocks are obtained from (meth)acrylic monomer(s)), more preferably than alkyl (meth)acrylate blocks, each block optionally further comprising one or more monomers chosen from (meth)acrylic acid, (meth)acrylic acid amides (preferably dialkyl (meth)acrylamides such as N,N-dimethylacrylamide), amino (meth)acrylates (preferably (meth)acrylates comprising a primary amine, such as 2-aminoethyl (meth)acrylate), epoxy (meth)acrylates (such as glycidyl (meth)acrylate), hydroxy (meth)acrylates (such as polyethylene glycol (meth)acrylate), alkoxy (meth)acrylates (such as 2-methoxyethyl (meth)acrylate), and mixtures thereof.

[0110] Advantageously, the acrylic block copolymer comprises at least one block A and at least one block B, the block A being a polymer comprising the methyl methacrylate monomer (i.e. methyl methacrylate is the only monomer or one of the monomers used to obtain the polymer), and the block B being a polymer not comprising a methyl methacrylate monomer. Preferably, the acrylic block copolymer is an AB diblock copolymer or an ABA triblock copolymer (the two A blocks being obtained from identical or different monomers), more preferably an ABA triblock copolymer.

[0111] Preferably, block A is a polymer obtained from a mixture of monomers comprising at least 50% by weight of methyl methacrylate per relative to the total weight of the monomer mixture, more preferably at least 75% by weight.

[0112] It is understood that “monomer mixture” refers to a mixture consisting of one or more monomers; consequently, when calculating the total weight of the monomer mixture, ingredients other than monomers (used during polymerization such as solvents, surfactants, etc.) are not taken into account.

[0113] When block A is a methyl methacrylate copolymer, the other monomer(s) constituting said copolymer may be chosen from methyl acrylate, ethyl (meth)acrylate, (meth)acrylic acid, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, (meth)acrylic acid amides (preferably dialkyl (meth)acrylamides such as N,N-dimethylacrylamide), 2-methoxyethyl (meth)acrylate, 2-aminoethyl (meth)acrylate, glycidyl (meth)acrylate, polyethylene glycol (meth)acrylate (PEG (meth)acrylate) where the PEG group has a molar mass ranging from 400 to 10000 g / mol, and their mixtures.

[0114] Preferably, block B is a polymer having a glass transition temperature (Tg) below 0°C, more preferably below -20°C. The Tg can be measured by differential scanning calorimetry (DSC).

[0115] Block B may be a polymer obtained from a mixture of monomers comprising at least 50% by weight of one or more monomers chosen from ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, hydroxyethyl acrylate, 2-ethylhexyl methacrylate, and mixtures thereof relative to the total weight of the mixture of monomers, preferably at least 50% by weight of n-butyl acrylate, more preferably at least 75% by weight of n-butyl acrylate.

[0116] The content of acrylic block copolymer can be up to 30% by weight relative to the total weight of the composition according to the invention, preferably up to 20% by weight, more preferably up to 10% by weight. Additives

[0117] The composition according to the invention may further comprise one or more additives chosen from crosslinking agents, fillers (other than the functionalized core-shell filler), thermal stabilizers, UV stabilizers (or antioxidants), ultraviolet or infrared fluorescent agents, dispersants, plasticizers, rheological agents, solvents, moisture absorbers, and mixtures thereof.

[0118] Advantageously, the composition according to the invention comprises a mixture of additives chosen from rheological agents and moisture absorbers.

[0119] The total content of additives can be up to 30% by weight relative to the total weight of the composition according to the invention, preferably between 1% and 20% by weight.

[0120] The crosslinking agent may be a multifunctional (meth)acrylate, preferably a multifunctional acrylate. For example, the crosslinker may be selected from polyethylene glycol di(meth)acrylates (such as diethylene, triethylene and / or tetraethylene glycol di(meth)acrylate), polypropylene glycol di(meth)acrylates (such as dipropylene glycol di(meth)acrylate), hexanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, tetramethylene glycol di(meth)acrylate, di(pentamethylene glycol di(meth)acrylate), ethylene di(meth)acrylate, bisphenol A di(meth)acrylate, bisphenol F di(meth)acrylate, and mixtures thereof.

[0121] The content of crosslinking agent can be up to 5% by weight relative to the total weight of the composition according to the invention.

[0122] The filler can be chosen from organic fillers, mineral fillers, and mixtures thereof.

[0123] As an example of mineral fillers, mention may be made of any mineral filler usually used in the field of adhesive compositions. These fillers are typically in the form of particles of various geometry. They may be, for example, spherical, fibrous, or have an irregular shape.

[0124] The mineral filler may be chosen from clays (such as talc), quartz, carbonate fillers (in particular calcium carbonate, which may be coated with fatty acids (the latter preferably being precipitated)), kaolins, gypsum, hollow mineral microspheres (in particular hollow glass microspheres, such as those made of sodium and calcium borosilicate or aluminosilicate), zeolites, and mixtures thereof.

[0125] The mineral filler may be untreated or treated, for example using an organic acid including stearic acid.

[0126] The average particle size of the mineral filler may range from 10 nm to 400 pm, preferably from 20 nm to 100 pm, more preferably from 30 nm to 50 pm.

[0127] In the present description, the average particle size advantageously corresponds to the particle size d50, i.e. the maximum size of 50% of the smallest particles by volume, and can be measured with a particle size analyzer, in particular by laser diffraction on a MALVERN type device (for example according to the ISO 13320 standard).

[0128] As an example of an organic filler, mention may be made of any organic filler, in particular polymeric, usually used in the field of adhesive compositions.

[0129] The organic filler can be chosen from polyvinyl chloride (PVC), po- lyolefins, ethylene vinyl acetate (EVA), expandable or non-expandable thermoplastic polymer hollow microspheres (such as vinylidene chloride / acrylonitrile hollow microspheres), aramid fibers (such as Kevlar®), and blends thereof.

[0130] The average particle size of the organic filler may be less than or equal to 50 pm, preferably between 5 and 20 pm.

[0131] The filler content can be up to 10% by weight relative to the total weight of the composition according to the invention.

[0132] The thermal stabilizer may be chosen from hydroquinone, methylhydroquinone, 2,6-di-tert-butyl-4-methoxyphenol, 2,4-dimethyl-6-tert-butylphenol (Topanol A).

[0133] The content of thermal stabilizer can be up to 3% by weight relative to the total weight of the composition according to the invention.

[0134] A UV stabilizer is typically introduced to prevent degradation resulting from a reaction with oxygen which is likely to be formed by the action of heat or light. UV stabilizers may include antioxidants capable of scavenging free radicals.

[0135] The UV stabilizer (or antioxidant) may be chosen from benzotriazoles, benzophenones, triazines (such as hydroxyphenyltriazines, in particular a mixture of 2-[4-[2-hydroxy-3-tridecyloxypropyl]oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine and 2-[4-[2-hydroxy-3-dodecyloxypropyl]oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine (CAS 153519-44-9)), phosphites (such as tris(2,4-di-tert-butylphenyl)phosphite), so-called hindered phenols (such as ethylenebis(oxyethylene)bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate], 2,2'-methylenebis(6-(tert-butyl)-4-methylphenol), 2,2'-methylenebis(6-(tert-butyl)-4-ethylphenol), 2,2'-methylenebis(4-methyl-6-cyclohexylphenol), 2,2'-methylenebis(4,6-di(tert-butyl)phenol), 4,4'-methylenebis(2,6-di(tert-butyl)phenol, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), 2,6-di(tert-butyl)-4-methylphenol), so-called hindered amines (such as bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate (CAS No: 41556-26-7), methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate (CAS No: 82919-37-7), 4,4'-bis(a,a-dimethylbenzyl)diphenylamine), and mixtures thereof.

[0136] The content of UV stabilizer (or antioxidant) can be up to 3% by weight relative to the total weight of the composition according to the invention.

[0137] For example, the ultraviolet or infrared fluorescent agent may be 2,5-thiophenediylbis(5-tert-butyl-1,3-benzoxazole).

[0138] The content of ultraviolet or infrared fluorescent agent can be up to 3% by weight relative to the total weight of the composition according to the invention.

[0139] For example, the dispersant may be selected from polycarboxylic acid polymers (especially maleic acid copolymers), polyhydroxycarboxylic acid amides (e.g., gluconic acid amides, glucoheptonic acid amides), and mixtures thereof. Commercial examples of dispersants are RHEOBYK-405 and BYK-P 105 by BYK.

[0140] The dispersant content can be up to 5% by weight relative to the total weight of the composition according to the invention.

[0141] The plasticizer may be any plasticizer commonly used in the field of adhesives.

[0142] For example, the plasticizer may be chosen from epoxy resins (such as those based on diglycidyl ether of bisphenol A), alkyl phthalates (such as diisodecyl phthalate, diisononyl phthalate, diisononyl hexahydrophthalate), benzoates (such as nonylbenzoate), alkylsulfonic acid esters of phenol (such as MESAMOLL® by LANXESS), pentaerythritol tetravalerate, diisononyl-1,2-cyclohexanedicarboxylate, 3,3'-methylenebis(oxymethylene)]bis[heptane], dioctyl carbonate, hydrocarbon oils (also called mineral oils, generally obtained from petroleum, such as paraffinic oils, naphthenic oils), natural oils (optionally epoxidized, such as epoxidized soybean oil), polypropylene, polybutylene, hydrogenated polyisoprene, and mixtures thereof.

[0143] The plasticizer content can be up to 8% by weight relative to the total weight of the composition according to the invention.

[0144] The rheological agent may be chosen from thixotropic agents, for example from: - PVC plastisols, corresponding to a suspension of PVC in a plasticizer miscible with PVC, obtained in situ by heating at temperatures ranging from 60°C to 80°C. These plastisols may be those described in particular in the work “Polyurethane Sealants”, Robert M. Evans, ISBN 087762-998-6, - fumed silica (preferably hydrophobic), - urea derivatives resulting from the reaction of a diisocyanate monomer, preferably aromatic such as diphenylmethylene diisocyanate (especially 4,4'-MDI), with a primary aliphatic amine such as butylamine, - waxes derived from castor oil, such as THIXCIN® R by ELEMENTIS, - amide waxes, preferably micronized, such as CRAYVALLAC® SLT by ARKEMA, and - their mixtures.

[0145] By "castor oil-derived waxes" is meant waxes obtained from castor oil, in particular hydrogenated castor oil.

[0146] By "amide waxes" is meant waxes comprising one or more compounds having at least one amide group. In particular, the amide waxes can be obtained from organic acid(s) (for example fatty acid(s)) and (di)amine(s).

[0147] The amide waxes are preferably micronized, that is to say they have an average particle size of less than 1 mm. Advantageously, the amide waxes have an average particle size of less than 500 μm, preferably less than 100 μm, more preferably less than 10 μm.

[0148] Preferably, the rheological agent is fumed silica, more preferably hydrophobic fumed silica.

[0149] The content of rheological agent can be up to 20% by weight relative to the total weight of the composition according to the invention, preferably between 3% and 15% by weight.

[0150] The solvent may be any solvent suitable for acrylic adhesive compositions.

[0151] The solvent content can be up to 5% by weight relative to the total weight of the composition according to the invention.

[0152] The moisture absorber may be an alkoxysilane such as a trialkoxysilane, in particular a trimethoxysilane. For example, the moisture absorber may be chosen from vinyltrimethoxysilane, trimethoxymethylsilane, propyltrimethoxysilane, vinyltriethoxysilane, alkoxyarylsilanes (for example GENIOSIL® XL 70 marketed by WACKER), and mixtures thereof, in particular vinyltrimethoxysilane.

[0153] The moisture absorber content can be up to 5% by weight relative to the total weight of the composition according to the invention, preferably between 0.5% and 4% by weight.

[0154] Other characteristics of the composition according to the invention

[0155] The composition according to the invention may be single-component or two-component, preferably single-component.

[0156] Advantageously, the composition according to the invention comprises less than 1% by weight of reducing agent chosen from tertiary amines derived from p-toluidine (such as N,N-diisopropanol-p-toluidine, N,N-dimethyl-p-toluidine, N,N-dihydroxyethyl-p-toluidine, N-(2-hydroxyethyl)-N-methyl-p-toluidine, 2-{[2-(2-hydroxyethoxy)ethyl](4-methylphenyl)amino}ethanol), tertiary amines derived from aniline (such as N,N-dimethylaniline, N,N-bis(2-hydroxypropyl)-p-aniline, N-(2-hydroxyethyl)-N-methylaniline, N,N-diisopropanol-p-chloroaniline, N,N-diisopropanol-p-bromoaniline, N,N-diisopropanol-p-bromo-m-methylaniline, N,N-dimethyl-p-chloroaniline, N,N-dimethyl-p-bromoaniline, N,N-diethyl-p-chloroaniline, N,N -diethyl-p-bromoaniline), N,N-dimethylaminomethylphenol, and mixtures thereof, preferably less than 0.1% by weight, more preferably less than 0.01% by weight.

[0157] According to one embodiment, the composition according to the invention comprises:

[0158] - between 20% and 80% by weight of a monofunctional (meth)acrylate monomer, said monomer preferably comprising at least 40% by weight of a cyclic alkyl acrylate relative to the total weight of said monomer,

[0159] - between 1% and 30% by weight of a functionalized core-shell filler, said filler preferably comprising a shell polymer and optionally one or more intermediate polymers, wherein at least one of the shell polymer and the optional intermediate polymer(s) comprises functional groups selected from epoxy groups, carboxylic acid groups, carboxamide groups, alkoxy groups, amine groups, cycloalkyl ester groups, and mixtures thereof,

[0160] - between 5% and 50% by weight of a (meth)acrylate polymer chosen from urethane (meth)acrylate polymers, polyester (meth)acrylate polymers, epoxy (meth)acrylate polymers, and mixtures thereof, preferably among urethane (meth)acrylate polymers,

[0161] - between 0.1% and 5% by weight of a photoinitiator,

[0162] - between 5% and 25% by weight of an adhesion promoter,

[0163] - optionally up to 30% by weight of an acrylic block copolymer,

[0164] - optionally up to 30% by weight one or more additives chosen from crosslinking agents, fillers (other than functionalized core-shell filler), thermal stabilizers, UV stabilizers (or antioxidants), ultraviolet or infrared fluorescent agents, dispersants, plasticizers, rheological agents, solvents, moisture absorbers, and mixtures thereof,

[0165] the percentages by weight being relative to the total weight of the composition according to the invention unless otherwise stated.

[0166] Preferably, the composition according to the invention consists essentially of the ingredients mentioned above. By "consisting essentially", it is meant that the composition according to the invention comprises less than 5% by weight of other ingredients than the above-mentioned ingredients, relative to the total weight of the composition, preferably less than 2% by weight, even more preferably less than 1% by weight.

[0167] The ingredients of this embodiment and their particular contents are as described above, including the preferred embodiments and characteristics.

[0168] In particular, the composition according to the invention comprises:

[0169] - between 40% and 60% by weight of a monofunctional (meth)acrylate monomer, said monomer preferably comprising at least 40% by weight, relative to the total weight of said monomer, of isobornyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, tert-butylcyclohexyl acrylate and / or (octahydro-4,7-methano-1H-indenyl)methyl acrylate,

[0170] - between 3% and 10% by weight of a functionalized core-shell filler, said filler preferably comprising a shell polymer and optionally one or more intermediate polymers, wherein at least one of the shell polymer and the optional intermediate polymer(s) comprises carboxamide and / or cycloalkyl ester groups,

[0171] - between 7% and 30% by weight of a (meth)acrylate polymer chosen from urethane (meth)acrylate polymers, polyester (meth)acrylate polymers, epoxy (meth)acrylate polymers, and mixtures thereof, preferably among urethane acrylate oligomers,

[0172] - between 0.8% and 3% by weight of a photoinitiator, preferably of type I,

[0173] - between 12% and 18% by weight of an adhesion promoter, the adhesion promoter preferably comprising at least 60% by weight of (meth)acrylic acid amide relative to the total weight of the adhesion promoter,

[0174] - optionally up to 10% by weight of an acrylic block copolymer,

[0175] - optionally between 1% and 20% by weight one or more additives chosen from crosslinking agents, fillers (other than functionalized core-shell filler), heat stabilizers, UV stabilizers (or antioxidants), ultraviolet or infrared fluorescent agents, dispersants, plasticizers, rheological agents, solvents, moisture absorbers, and mixtures thereof,

[0176] the percentages by weight being relative to the total weight of the composition according to the invention unless otherwise stated.

[0177] Preferably, the composition according to the invention consists essentially of the ingredients mentioned above.

[0178] The ingredients of this embodiment and their particular contents are as described above, including the preferred embodiments and characteristics.

[0179] Advantageously, the composition according to the invention has a shear strength on polycarbonate of at least 7 MPa, preferably between 7 MPa and 12 MPa. The re Shear strength can be measured according to ISO 4587 (2003), for example as shown in Example 1 below.

[0180] The composition according to the invention can be prepared by simple mixing of its ingredients. An example of preparation is described in Example 2 below. Use of the composition according to the invention

[0181] The present invention also relates to the use of the composition according to the invention as an adhesive, coating, UV ink or in 3D printing, preferably as an adhesive, in particular in the field of building construction, in the field of manufacturing means of transport (such as the automobile, railway, aerospace, naval industries), electronics, luxury products or medical products (such as the assembly of perfume bottles, alcohol bottles, makeup displays, dental products).

[0182] The composition according to the invention is as described above, including the preferred embodiments and characteristics. Substrate assembly process

[0183] The present invention also relates to a method for assembling substrates comprising:

[0184] - coating, on at least one surface of the substrates to be assembled, the composition according to the invention as described above (including preferred embodiments and features), then

[0185] - bringing the substrates into contact, then

[0186] - crosslinking of the composition.

[0187] It is understood that, during the coating step and the contacting step, the composition according to the invention is in the non-crosslinked state.

[0188] The crosslinking step can be carried out at a temperature between 10°C and 40°C, preferably between 15°C and 30°C, in particular at room temperature (for example between 18°C ​​and 25°C).

[0189] The crosslinking step can be carried out under electromagnetic irradiation at a wavelength between 100 nm and 680 nm, preferably between 315 nm and 420 nm, more preferably between 360 nm and 410 nm.

[0190] The crosslinking step under electromagnetic irradiation can be carried out with a UV radiation source, preferably with an LED.

[0191] The substrates may be the same or different.

[0192] A wide variety of substrates can be implemented. They can for example be plastic, glass, metal and / or composite. Preferably, at least one substrate is plastic, more preferably the substrates are plastics.

[0193] The plastic may be PVC, polycarbonate, polymethyl methacrylate (PMMA), polystyrene, polyethylene, polypropylene and / or acrylonitrile butadiene styrene (ABS), preferably PVC, polycarbonate, PMMA, polystyrene and / or ABS, in particular polycarbonate.

[0194] The metal may be pure or an alloy, for example aluminum or steel (including stainless steel).

[0195] The composite may be a reinforced plastic, such as a fiber-reinforced plastic, especially a sheet molding composite (SMC). The fibers of the fiber-reinforced plastic may be glass, carbon, aramid, or basalt fibers, preferably glass fibers. The fiber length may vary between 6 mm and 50 mm. The polymer in the reinforced plastic may be a polyester, polyolefin, epoxy, or vinyl ester resin. The polymer in the reinforced plastic is preferably unsaturated. The reinforced plastic may include other compounds than the fibers and the polymer (such as filler and / or catalyst). Article

[0196] The present invention also relates to an article comprising the composition according to the invention (in the crosslinked state or not) as described above (including the preferred embodiments and characteristics), said composition binding at least two substrates of said article.

[0197] The article can be obtained by the substrate assembly method according to the invention (including preferred embodiments and characteristics).

[0198] The substrates are preferably as described above for the method of assembling substrates according to the invention, in particular the substrates are preferably made of plastic, in particular polycarbonate.

[0199] All the embodiments described above can be combined with each other. In particular, the various aforementioned constituents of the composition, and in particular the preferred embodiments, can be combined with each other.

[0200] The following examples are given purely for illustrative purposes of the invention and should not be interpreted as limiting its scope. Examples Example 1: Ingredients and measurement methods Ingredients used

[0201] The following ingredients were used:

[0202] - SR506D marketed by SARTOMER: isobornyl acrylate,

[0203] - NNDMA: N,N-dimethylacrylamide, adhesion promoter,

[0204] - SR489 marketed by SARTOMER: tridecyl acrylate,

[0205] - Core-shell A: polybutadiene-poly(methyl methacrylate) core-shell filler functionalized isobornyl acrylate,

[0206] - Core-shell B: polybutadiene-poly(methyl methacrylate) core-shell filler functionalized N,N-dimethylacrylamide,

[0207] - Core-shell C: polybutadiene-poly(methyl methacrylate) core-shell filler not functionalized,

[0208] - AA: glacial acrylic acid, adhesion promoter,

[0209] - MAA: methacrylic acid, adhesion promoter,

[0210] - CN966H90 marketed by SARTOMER: urethane diacrylate oligomer ali phatic based on a polyester mixed with 10% by weight of (2-(2-ethoxyethoxy)ethylacrylate) relative to the total weight of the mixture,

[0211] - SPEEDCURE 2100 marketed by SARTOMER: mixture of phenyl- ethyl-(2,4,6-trimethylbenzoyl)phosphinate (CAS: 84434-11-7) and phenylbis-(2,4,6-trimethylbenzoyl)phosphine oxide (CAS: 162881-26-7), photoinitiator,

[0212] - Omnirad 1173 marketed by IGM Resins: 2-hydroxy-2-methylpropiophenone, photoinitiator,

[0213] - JH-V171 marketed by Jingzhou Jianghan Fine Chemical: vinyltrimé- thoxysilane, moisture absorber,

[0214] - AEROSIL® R 812 S marketed by Evonik: hydrophobic fumed silica (treatment with hexamethyldisilazane), rheological agent. Preparation of the heart-bark A

[0215] Core-shell filler A is in the form of a multi-step core-shell polymer comprising a core and two shell layers, and is prepared according to the method as described in WO2020 / 260638 for core / shell filler-2, except that 30 wt% of the MM A in the synthesis of the two shell layers is replaced by isocarboxylic acid. The volume average particle diameter after the multi-step polymerization is about 170 nm (measured by dynamic light scattering with a Malvern Zetasizer). The resulting product is coagulated with sulfuric acid and dried. Preparation of the heart-bark B

[0216] Core-shell filler B was prepared as described below for core-shell filler C, except that in the second step B, 2.26 parts of the MMA were replaced with N,N-dimethylacrylamide (DMA). Preparation of the heart-bark C

[0217] Step A - Polymerization of an Al polymer: Into a 20 liter high pressure reactor were charged: 116.5 parts of deionized water, 0.1 part of a beef tallow fatty acid potassium salt emulsifier, 21.9 parts of 1,3-butadiene, 0.1 part of t-dodecyl mercaptan and 0.1 part of p-menthane hydroperoxide as initial charge. The solution was heated, with stirring, to 43°C, at which time a solution of redox-based catalyst was charged (4.5 parts water, 0.3 parts sodium tetrapyrophosphate, 0.004 parts ferrous sulfate, and 0.3 parts dextrose), effectively initiating polymerization. Then, the solution was further heated to 56°C and held at this temperature for a period of three hours. Three hours after polymerization initiation, a second charge of monomer (77.8 parts 1,3-butadiene, 0.2 parts t-dodecyl mercaptan), half of an additional emulsifying and reducing agent charge (30.4 parts deionized water, 2.8 parts beef tallow fatty acid potassium salt emulsifier, 0.5 parts dextrose), and additional initiator (0.8 parts p-menthane hydroperoxide) were added continuously for eight hours. After the addition of the second monomer was completed, the remaining emulsifying and reducing filler and initiator were added continuously for an additional five hours.Thirteen hours after initiation of polymerization, the solution was heated to 68°C and allowed to react until at least twenty hours had elapsed since initiation of polymerization, producing a polybutadiene rubber latex RI. The resulting polybutadiene rubber latex (Al) contained 38% solids and had a weight average particle size of approximately 160 nm.

[0218] Step B - Polymerization of a polymer B1: Into a 3.9 liter reactor were charged 75.0 parts, on a solid basis, of polybutadiene rubber latex RI, 37.6 parts of deionized water and 0.1 part of sodium formaldehyde sulfoxylate. The solution was stirred, purged with nitrogen and heated to 77°C. When the solution reached 77°C, a mixture of 22.6 parts of methyl methacrylate (MMA), 1.4 parts of 1,4-butanediol dimethacrylate (BDMA) and 0.1 part of t-butyl hydroperoxide initiator was added continuously for 70 minutes, followed by a holding period of 80 minutes. Thirty minutes after the start of the holding period, 0.1 part of sodium formaldehyde sulfoxylate and 0.1 part of t-butyl hydroperoxide were added to the reactor at one time. After the 80-minute holding period, a stabilizing emulsion was added to the graft copolymer latex.The stabilizing emulsion was prepared by mixing 3.2 parts of deionized water (based on the mass of graft copolymer), 0.1 part of oleic acid, 0.1 part of potassium hydroxide, and 0.9 parts of octadecyl-3-(3,5-di-tertbutyl-4-hydroxyphenyl)propionate. The resulting core-shell polymer (Al+Bl) had a weight-average particle size of about 180 nm.

[0219] Step C - Polymerization of a polymer Cl (semi-continuous process): 10,000g of core-shell polymer (Al+Bl) still in dispersion in deionized water, 0.01g of FeSO4 and 0.032g of sodium salt of ethylenediaminetetraacetic acid (dissolved in 10g of deionized water) were loaded into a stirred reactor. 3.15 g of sodium formaldehyde sulfoxylate dissolved in 110 g of deionized water and 21.33 g of beef tallow fatty acid potassium salt emulsifier (dissolved in 139.44 g of water), and the mixture was stirred until the added raw materials were completely dissolved except for the core-shell polymer. Three vacuum-nitrogen purges were carried out successively and the reactor was left under slight vacuum. The reactor was then heated. At the same time, a mixture comprising 1066.7 g of methyl methacrylate and 10.67 g of n-octyl mercaptan was degassed with nitrogen for 30 minutes. The reactor was heated to 63 °C and maintained at this temperature. Then, the monomeric mixture was introduced into the reactor within 180 minutes using a pump. At the same time, a solution of 5.33g of tert-butyl hydroperoxide (dissolved in 100g of deionized water) was introduced (same addition time). The lines were rinsed with 50g and 20g of water.Then the reaction mixture was heated to a temperature of 80°C and the polymerization was then left to complete for 60 minutes after the addition of the monomers was complete. The reactor was cooled to 30°C.

[0220] The core-shell charge C was then recovered (A1+B1+C1) in powder form by spray drying. Shear strength (LSS)

[0221] Lap shear strength was measured according to ISO 4587 (2003). A 250 μm thickness of the test composition was applied at approximately 23°C between two polycarbonate sheets, each sheet having a thickness of 4 mm. The lap shear strength was measured at 23°C, 24 h after irradiating the assembly for 30 seconds with a LED centered at 385 nm, placed at a distance of 8 cm. The shear stress was applied via a tensile machine at a constant speed of 5 mm / min.

[0222] By “approximately X”, we mean more or less 10% of the value of X. Transparency

[0223] Transparency was visually assessed for assemblies between two glass plates, prepared in the same way as for the shear strength tests.

[0224] Example 2: Preparation of compositions according to the invention and comparative

[0225] The compositions were prepared with the ingredients indicated in Table 1, the values ​​indicated for each composition being percentages by weight relative to the total weight of the composition. For compositions comprising a core-shell filler, this filler was first dispersed at atmospheric pressure using a deflocculating turbine in a portion of the CN966H90 (so as to obtain between 20% and 60% by weight of filler relative to the total weight of filler and CN966H90); friction increased the temperature of the mixture to approximately 60°C. Then, the remainder of the CN966H90 was introduced and stirring was continued until there was no more presence of grains. The remaining ingredients were then added and stirring was continued until homogenized.

[0226] [Tables 1] Ingredient 1 (comp.) 2 (comp.) 3 (inv.) 4 (inv.) SR506D 30.1 27.9 27.9 27.9 NNDMA 14 13 13 13 SR489 19.1 18 18 18 Core-shell A - - - 6 Core-shell B - - 6 - Core-shell C - 6 - - AA 0.5 0.5 0.5 0.5 MAA 2 2 2 2 CN966H90 26.6 24.9 24.9 24.9 SPEEDCURE 2100 1.3 1.3 1.3 1.3 Omnirad 1173 0.4 0.4 0.4 0.4 JH-V171 2 2 2 2 AEROSIL® R 812 S 4 4 4 4

[0227] Example 3: Properties of the compositions prepared in Example 2

[0228] The properties of the compositions prepared in Example 2 were evaluated according to the methods described in Example 1.

[0229] The addition of a non-functionalized core-shell filler makes it possible to increase the shear strength (comparison of comparative compositions 1 and 2).

[0230] However, the addition of a functionalized core-shell filler makes it possible to further increase the shear strength (comparison of compositions 3 and 4 according to the invention with comparative composition 2).

[0231] Furthermore, composition 4 according to the invention has the advantage of being more transparent than comparative composition 2.

Claims

Claims

1. Photocrosslinkable composition comprising: - a monofunctional (meth)acrylate monomer, - a functionalized core-shell filler, - a (meth)acrylate polymer, preferably a (meth)acrylate oligomer, chosen from urethane (meth)acrylate polymers, polyester (meth)acrylate polymers, epoxy (meth)acrylate polymers, and mixtures thereof, and - a photoinitiator.

2. A photocrosslinkable composition according to claim 1, wherein the monofunctional (meth)acrylate monomer comprises at least 40% by weight of a cyclic alkyl acrylate (preferably isobornyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, tert-butylcyclohexyl acrylate and / or (octahydro-4,7-methano-1H-indenyl)methyl acrylate), relative to the total weight of the monofunctional (meth)acrylate monomer, preferably at least 50% by weight, more preferably at least 60% by weight.

3. A photocrosslinkable composition according to claim 1 or 2, wherein the monofunctional (meth)acrylate monomer comprises a cyclic alkyl acrylate and an acyclic alkyl acrylate.

4. A photocrosslinkable composition according to any one of claims 1 to 3, wherein the functionalized core-shell filler comprises a core comprising a core polymer, a shell comprising a shell polymer and optionally one or more intermediate polymers between the core polymer and the shell polymer, wherein at least one of the shell polymer and the optional intermediate polymer(s) comprises functional groups which may be selected from epoxy groups, carboxylic acid groups, carboxamide groups, alkoxy groups, amine groups, cycloalkyl ester groups, and mixtures thereof, preferably from carboxamide groups, cycloalkyl ester groups, and mixtures thereof, more preferably from cycloalkyl ester groups.

5. Photocrosslinkable composition according to any one of claims 1 to 4, in which the (meth)acrylate polymer is chosen from urethane (meth)acrylate polymers.

6. A photocrosslinkable composition according to any one of the claims

7.

8.

9.

10.

11. 1 to 5, wherein the (meth)acrylate polymer has a glass transition temperature of less than 30°C, preferably less than 0°C. Photocrosslinkable composition according to any one of claims 1 to 6, further comprising an adhesion promoter. Photocrosslinkable composition according to any one of claims 1 to 7, comprising: - between 20% and 80% by weight of a monofunctional (meth)acrylate monomer, - between 1% and 30% by weight of a functionalized core-shell filler, - between 5% and 50% by weight of a (meth)acrylate polymer chosen from urethane (meth)acrylate polymers, polyester (meth)acrylate polymers, epoxy (meth)acrylate polymers, and mixtures thereof, - between 0.1% and 5% by weight of a photoinitiator, - between 5% and 25% by weight of an adhesion promoter, - optionally up to 30% by weight of an acrylic block copolymer, - optionally up to 30% by weight one or more additives chosen from crosslinking agents, fillers, heat stabilizers, UV stabilizers, ultraviolet or infrared fluorescent agents, dispersants, plasticizers, rheological agents, solvents, moisture absorbers, and mixtures thereof, the percentages by weight being relative to the total weight of the composition. Use of the photocrosslinkable composition according to any one of claims 1 to 8 as an adhesive, coating, UV ink or in 3D printing, preferably as an adhesive. Method of assembling substrates comprising: - coating, on at least one surface of the substrates to be assembled, the photocrosslinkable composition according to any one of claims 1 to 8, then - bringing the substrates into contact, then - crosslinking of the composition. An article comprising the photocrosslinkable composition according to any one of claims 1 to 8, said composition binding at least two substrates of said article.