Photo-crosslinkable composition

Abstract

This 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 selected from urethane (meth)acrylate polymers, polyester (meth)acrylate polymers, epoxy (meth)acrylate polymers, and mixtures thereof, and - a photoinitiator. The invention also relates to the use of the composition according to the invention as an adhesive, coating, UV ink, or in 3D printing. The invention further relates to a method for assembling substrates, comprising: - applying the composition according to the invention to at least one surface of a substrate to be assembled, then - bringing the substrates into contact, and then - crosslinking the composition. Finally, the invention relates to articles comprising the composition according to the invention, said composition bonding said article to at least two substrates.

Description

Technical Field

[0001] This invention relates to photocrosslinkable compositions and their uses, methods for assembling substrates, and articles thereof. Background Technology

[0002] Acrylic compositions are known reactive systems that are crosslinked through free radical polymerization.

[0003] Compositions that undergo polymerization by exposing the composition to light are called "photopolymerizable" or "photocrosslinkable" compositions. The constituent monomers of the matrix are typically designed to form thermosetting polymers through the crosslinking of polymer chains. Such compositions can polymerize rapidly and completely by simply exposing them to light, especially UV light, making them very easy to use. Furthermore, they can be formulated as single-component compositions, which significantly saves time compared to two-component compositions (which especially require a preparatory step of mixing the two components before application).

[0004] However, photocrosslinkable acrylic compositions, especially polymer networks obtained by crosslinking through exposure to light, generally exhibit mechanical properties, particularly adhesive strength and shear strength, that are inferior to those of two-component acrylic compositions polymerized via redox systems. Therefore, they may prove unsuitable for certain industrial applications.

[0005] Therefore, there is a need to provide photocrosslinkable acrylic compositions with improved adhesive strength, especially improved shear strength.

[0006] Furthermore, it would be advantageous to provide a photocrosslinkable acrylic composition with transparent properties, so that it does not block the passage of light when applied to a transparent substrate. Summary of the Invention

[0007] This invention relates to a photocrosslinkable composition comprising:

[0008] - Monofunctional (meth)acrylate monomers,

[0009] -Functionalized core-shell filler

[0010] - (meth)acrylate polymers, preferably (meth)acrylate oligomers, selected from urethane (meth)acrylate polymers, polyester (meth)acrylate polymers, epoxy (meth)acrylate polymers, and mixtures thereof, and

[0011] - Photoinitiator.

[0012] The present invention also relates to the use of the compositions according to the invention as adhesives, coatings, UV inks or in 3D printing, preferably as adhesives.

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

[0014] - The composition according to the invention is applied to at least one surface of the substrate to be assembled, and then

[0015] -Make the substrate come into contact, and then

[0016] - To crosslink the composition.

[0017] Finally, the present invention relates to articles comprising a composition according to the invention, the composition bonding at least two substrates of the article.

[0018] This invention enables the fulfillment of one or more of the above-mentioned requirements. In particular, the compositions according to the invention have improved shear strength. Detailed Implementation

[0019] Composition

[0020] The composition according to the invention is photocrosslinkable, that is, the crosslinking of the composition is triggered by exposure to electromagnetic radiation, preferably ultraviolet (UV) radiation.

[0021] Monofunctional (meth)acrylate monomers

[0022] The compositions according to the invention comprise a monofunctional (meth)acrylate monomer, that is, a monomer comprising exactly one (meth)acrylate group.

[0023] In this document, unless otherwise stated (e.g., "exactly one"), "one" or "a" means one or more (one or more types).

[0024] In this article, "(meth)acrylate" should be understood to mean methacrylate or acrylate.

[0025] Advantageously, the monofunctional (meth)acrylate monomer has the formula (I): CH2=C(R) a )-COOR b ,in:

[0026] -R a Represents a hydrogen atom or a methyl group, preferably a hydrogen atom.

[0027] -R b Represents an aliphatic or aromatic hydrocarbon group, optionally comprising one or more groups selected from ethers, esters, hydroxyl groups, carbonyl groups, and mixtures thereof; preferably, R b It indicates an aliphatic or aromatic hydrocarbon group (excluding heteroatoms), more preferably an alkyl group.

[0028] In this article, "alkyl" should be understood to mean an acyclic or cyclic (that is, containing an aliphatic ring) aliphatic hydrocarbon group that does not contain a carbon-carbon double bond.

[0029] When R b When representing an alkyl group, the monofunctional (meth)acrylate monomer can be selected from (meth)acrylate C1-C... 22 Alkyl esters, preferably (meth)acrylates C1-C 18 Alkyl esters, more preferably (meth)acrylic acid C8-C 15 Alkyl esters.

[0030] In this article, "(meth)acrylic acid C" X -C Y "Alkyl ester" should be understood as referring to alkyl esters of (meth)acrylic acid, wherein the alkyl group contains X to Y carbon atoms.

[0031] In this article, "(meth)acrylic acid" should be understood as referring to methacrylic acid or acrylic acid.

[0032] For example, monofunctional (meth)acrylate monomers may be selected from methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, 2-octyl methacrylate, isooctyl methacrylate, n-octyl methacrylate, n-decyl methacrylate, dodecyl methacrylate, tridecyl methacrylate, tetradecyl methacrylate, hexadecyl methacrylate, octadecyl methacrylate, tricyclodecaneethanol (meth)acrylate, isobornyl methacrylate, 3,3,5-trimethylcyclohexyl methacrylate, tert-butylcyclohexyl methacrylate, dicyclopentyl methacrylate (CAS 7398-56-3), and methyl (octahydro-4,7-methylene-1H-indenyl)methacrylate (CAS 7398-56-3). 127823-21-6), optionally ethoxylated benzyl (meth)acrylate (that is, containing at least one -O-(CH2CH2O)). n- group, where n is not 0), 2-(2-ethoxyethoxy)ethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate and mixtures thereof, preferably selected from isobornyl (meth)acrylate, 3,3,5-trimethylcyclohexyl (meth)acrylate, tert-butylcyclohexyl (meth)acrylate, (octahydro-4,7-methylene-1H-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 acrylate and mixtures thereof, more preferably selected from isoborneol acrylate, 3,3,5-trimethylcyclohexyl acrylate, tert-butylcyclohexyl acrylate, (octahydro-4,7-methylene-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, especially isoborneol acrylate and mixtures of other monomers selected from dodecyl acrylate, tridecyl acrylate and mixtures thereof, optionally with 2-(2-ethoxyethoxy)ethyl acrylate.

[0033] Advantageously, relative to the total weight of the monofunctional (meth)acrylate monomers, the monofunctional (meth)acrylate monomers comprise at least 40% by weight, preferably at least 50% by weight, and more preferably at least 60% by weight of cyclic alkyl acrylates (preferably isobornyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, tert-butylcyclohexyl acrylate, and / or methyl (octahydro-4,7-methylene-1H-indenyl)acrylate). Preferably, relative to the total weight of the monofunctional (meth)acrylate monomers, the monofunctional (meth)acrylate monomers comprise at least 40% by weight, preferably at least 50% by weight, and more preferably at least 60% by weight of isobornyl acrylate.

[0034] According to one embodiment, the monofunctional (meth)acrylate monomer comprises cyclic alkyl acrylates and acyclic alkyl acrylates.

[0035] Preferably, the monofunctional (meth)acrylate monomer comprises:

[0036] - Relative to the total weight of the monofunctional (meth)acrylate monomers, at least 40% by weight, preferably at least 50% by weight, more preferably at least 60% by weight, of cyclic alkyl acrylates, preferably isobornyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, tert-butylcyclohexyl acrylate and / or (octahydro-4,7-methylene-1H-indenyl)methyl acrylate, more preferably isobornyl acrylate, and

[0037] - Relative to the total weight of monofunctional (meth)acrylate monomers, between 1% and 60% by weight, preferably between 5% and 50% by weight, more preferably between 10% and 40% by weight, acycloalkyl acrylates, preferably n-octyl acrylate, n-decyl acrylate, dodecyl acrylate, tridecyl acrylate, tetradecyl acrylate, hexadecyl acrylate and / or octadecyl acrylate, especially dodecyl acrylate and / or tridecyl acrylate.

[0038] The content of the monofunctional (meth)acrylate monomer may be between 20% by weight and 80% by weight, preferably between 30% by weight and 70% by weight, and more preferably between 40% by weight and 60% by weight, relative to the total weight of the composition according to the invention.

[0039] In the context of this invention, the range of values ​​should be understood to mean including limits. For example, the range "between 0% and 25%" specifically includes the values ​​0% and 25%.

[0040] Functionalized core-shell fillers

[0041] The compositions according to the invention comprise functionalized core-shell fillers.

[0042] Core-shell fillers are generally described as polymeric substances, typically in particulate form, comprising a core (inner portion) containing a core polymer (or consisting essentially of a core polymer) and a shell (outer portion) containing a shell polymer (or consisting essentially of a shell polymer). One or more intermediate polymer layers may be included between the core and shell polymers. "Constitutes essentially of" should be understood to mean that, relative to the total weight of the core (or shell) polymer, the core (or shell) advantageously contains less than 5% by weight, preferably less than 2% by weight, and more preferably less than 1% by weight of compounds other than the core (or shell) polymer.

[0043] Typically, the glass transition temperature of the shell polymer is greater than that of the core polymer. The glass transition temperature of the core-shell filler polymer can be measured according to standard ISO 11357-2, for example, at a heating rate of 20°C / min. Typically, the glass transition temperature of the core polymer is less than 10°C, preferably less than 0°C, more preferably less than -20°C. Typically, the glass transition temperature of the shell polymer is greater than 60°C, preferably greater than 80°C, more preferably greater than 100°C.

[0044] Unless otherwise stated, the standards mentioned throughout the application are those that were in effect as of the date of filing.

[0045] The core polymer may comprise polymers (homopolymers and / or copolymers) of conjugated dienes containing 4 to 12 carbon atoms, preferably 4 to 8 carbon atoms (e.g., isoprene and / or butadiene), and / or polymers (homopolymers and / or copolymers) of acyclic alkyl esters of (meth)acrylates, wherein the (linear or branched) alkyl chain contains 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms (e.g., butyl acrylate).

[0046] Advantageously, the core polymer comprises a polymer of conjugated dienes (or consists essentially of polymers of conjugated dienes selected from isoprene, butadiene, and mixtures thereof, preferably butadiene. Preferably, the core polymer comprises (or consists essentially of): isoprene homopolymer, butadiene homopolymer, isoprene-butadiene copolymer, butadiene-styrene copolymer, and / or isoprene-styrene copolymer, more preferably butadiene homopolymer.

[0047] "consistent with" should be understood as meaning that, relative to the total weight of the core polymer, the core polymer advantageously contains less than 5% by weight of polymers other than those described above, preferably less than 2% by weight, more preferably less than 1% by weight.

[0048] The core polymer may be crosslinked. The crosslinking agent / monomer may be selected from polyfunctional vinyl aromatic compounds such as divinylbenzene and divinyltoluene, polyols such as ethylene glycol di(meth)acrylate and 1,3-butanediol di(meth)acrylate, tri(meth)acrylate, allyl carboxylate such as allyl acrylate and allyl methacrylate, and diallyl and triallyl compounds such as diallyl phthalate, diallyl sebacate and triallyl triazine.

[0049] The shell polymer may comprise a polymer (homopolymer and / or copolymer) of acyclic alkyl esters of (meth)acrylate, wherein the (straight-chain or branched) alkyl chain contains 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms, such as methyl methacrylate.

[0050] When one or more intermediate polymer layers are present, each intermediate polymer may comprise a polymer (homopolymer and / or copolymer) of acyclic alkyl esters of (meth)acrylate, wherein the (linear or branched) alkyl chain comprises 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms, such as methyl methacrylate. Each intermediate polymer may be the same as or different from the shell polymer.

[0051] The core-shell filler is "functionalized" because at least one of the shell polymer and optionally the intermediate polymer contains a functional group different from the polymerization-derived group of the (meth)acrylate acycloalkyl ester (i.e., different from the acycloalkyl ester remaining after the polymerization of the (meth)acrylate). These functional groups can be selected from epoxy groups (e.g., glycidyl groups), carboxylic acid groups, carboxamide groups (preferably N,N-dialkylcarboxamide groups), alkoxy groups (e.g., methoxy, ethoxy), amine groups (e.g., primary amines), and cycloalkyl ester groups (preferably C8-C). 12 The cycloalkyl group, such as isobornyl, 3,3,5-trimethylcyclohexyl, tert-butylcyclohexyl and / or (octahydro-4,7-methylene-1H-indenyl)methyl ester and mixtures thereof, is preferably selected from carboxamide groups, cycloalkyl ester groups and mixtures thereof, and more preferably from cycloalkyl ester groups. Preferably, the functional group is derived from a functionalized (meth)acrylate, more preferably from a functionalized acrylate; for example, it can be introduced by grafting the polymer to be functionalized (shell polymer, intermediate polymer) with a functionalized (meth)acrylate or by introducing the functionalized (meth)acrylate during the polymerization of the polymer to be functionalized. The functional (meth)acrylate may be selected from glycidyl (meth)acrylate, (meth)acrylic acid, (meth)acrylamide, 2-methoxyethyl (meth)acrylate, (meth)acrylates containing primary amines (e.g., 2-aminoethyl (meth)acrylate), cycloalkyl (meth)acrylates, and mixtures thereof, preferably selected from (meth)acrylamide, cycloalkyl (meth)acrylates, and mixtures thereof, more preferably selected from N,N-dialkylamides of (meth)acrylic acid (e.g., dimethacrylamide), and C8-C (meth)acrylates. 12 Cycloalkyl esters (e.g., isobornyl (meth)acrylate, 3,3,5-trimethylcyclohexyl ester, tert-butylcyclohexyl ester and / or (octahydro-4,7-methylene-1H-indenyl)methyl ester) and mixtures thereof, even more preferably C8-C(meth)acrylate. 12 Cycloalkyl esters, especially isobornyl (meth)acrylate.

[0052] According to a preferred embodiment, the functional (meth)acrylate is a functional acrylate selected from glycidyl acrylate, acrylic acid, acrylamide, 2-methoxyethyl acrylate, acrylates containing primary amines (e.g., 2-aminoethyl acrylate), cycloalkyl acrylates, and mixtures thereof, preferably selected from acrylamide, cycloalkyl acrylates, and mixtures thereof, more preferably selected from N,N-dialkylamides of acrylic acid (e.g., dimethacrylamide), and C8-C acrylates. 12 Cycloalkyl esters (e.g., isobornyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, tert-butylcyclohexyl acrylate and / or (octahydro-4,7-methylene-1H-indenyl)methyl acrylate) and mixtures thereof, even more preferably C8-C acrylates.12 Cycloalkyl esters, especially isobornyl acrylate.

[0053] According to the first embodiment, the core-shell filler does not contain an intermediate polymer. According to this embodiment, the shell polymer comprises (or substantially consists of) a copolymer of (meth)acyclic alkyl acrylate and a functionalized (meth)acrylate. Advantageously, the (meth)acrylate acyclic alkyl acrylate is selected from methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, and mixtures thereof, preferably methyl methacrylate. The functionalized (meth)acrylate can be, as described above, preferably selected from (meth)acrylamide, (meth)acrylate cycloalkyl esters, and mixtures thereof, more preferably selected from N,N-dialkylamides of (meth)acrylate (e.g., dimethacrylamide), and (meth)acrylate C8-C... 12 Cycloalkyl esters (e.g., isobornyl (meth)acrylate, 3,3,5-trimethylcyclohexyl ester, tert-butylcyclohexyl ester and / or (octahydro-4,7-methylene-1H-indenyl)methyl ester) and mixtures thereof, even more preferably C8-C(meth)acrylate. 12 Cycloalkyl esters, particularly isobornyl (meth)acrylate. Advantageously, the functional (meth)acrylate is a functional acrylate, preferably selected from acrylamides, cycloalkyl acrylates and mixtures thereof, more preferably selected from N,N-dialkylamides of acrylic acid (e.g., dimethacrylamide), C8-C acrylates. 12 Cycloalkyl esters (e.g., isobornyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, tert-butylcyclohexyl acrylate and / or (octahydro-4,7-methylene-1H-indenyl)methyl acrylate) and mixtures thereof, even more preferably C8-C acrylates. 12 Cycloalkyl esters, especially isobornyl acrylate.

[0054] Specifically, the shell polymer comprises (or is substantially composed of) a copolymer containing at least 70% by weight of repeating units derived from methyl methacrylate relative to the total weight of the copolymer.

[0055] "consistent with..." should be understood to mean that, relative to the total weight of the shell polymer, the shell polymer advantageously contains less than 5% by weight, preferably less than 2% by weight, more preferably less than 1% by weight of polymers other than the copolymers mentioned above.

[0056] The shell polymer may be crosslinked, and is preferably crosslinked. The crosslinking agent / monomer may be selected from polyfunctional vinyl aromatic compounds such as divinylbenzene and divinyltoluene, polyols such as ethylene glycol di(meth)acrylate and 1,3-butanediol di(meth)acrylate, tri(meth)acrylate, allyl carboxylate such as allyl acrylate and allyl methacrylate, and diallyl and triallyl compounds such as diallyl phthalate, diallyl sebacate, and triallyl triazine.

[0057] According to the second embodiment, the core-shell filler does not contain an intermediate polymer. According to this embodiment, at least one of the shell polymer and the intermediate polymer comprises (or is substantially composed of) a copolymer of an acycloalkyl ester of (meth)acrylate and a functionalized (meth)acrylate. Advantageously, the acycloalkyl ester of (meth)acrylate is selected from methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, and mixtures thereof, preferably methyl methacrylate. The functionalized (meth)acrylate can be as described above, preferably selected from (meth)acrylamide, cycloalkyl esters of (meth)acrylate, and mixtures thereof, more preferably selected from N,N-dialkylamides of (meth)acrylate (e.g., dimethacrylamide), and C8-C of (meth)acrylate. 12 Cycloalkyl esters (e.g., isobornyl (meth)acrylate, 3,3,5-trimethylcyclohexyl ester, tert-butylcyclohexyl ester and / or (octahydro-4,7-bridged methylene-1H-indenyl)methyl ester) and mixtures thereof, even more preferably C8-C(meth)acrylate. 12 Cycloalkyl esters, particularly isobornyl (meth)acrylate. Advantageously, the functional (meth)acrylate is a functional acrylate, preferably selected from acrylamide, cycloalkyl acrylate, and mixtures thereof, more preferably selected from N,N-dialkylamides of acrylic acid (e.g., dimethacrylamide), C8-C acrylate. 12 Cycloalkyl esters (e.g., isobornyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, tert-butylcyclohexyl acrylate and / or (octahydro-4,7-methylene-1H-indenyl)methyl acrylate) and mixtures thereof, even more preferably C8-C acrylates. 12 Cycloalkyl esters, especially isobornyl acrylate.

[0058] Specifically, the shell polymer and the intermediate polymer comprise (or consist substantially of) polymers containing at least 70% by weight of repeating units derived from methyl methacrylate relative to the total weight of the polymer.

[0059] "consistent with..." should be understood to mean that, relative to the total weight of the shell / intermediate polymer, the shell polymer and the intermediate polymer advantageously contain less than 5% by weight, preferably less than 2% by weight, more preferably less than 1% by weight of polymers other than those described above.

[0060] Both the shell and the intermediate polymer may be crosslinked. Preferably, the intermediate polymer is crosslinked. The crosslinking agent / monomer may be selected from polyfunctional vinyl aromatic compounds such as divinylbenzene and divinyltoluene, polyols such as ethylene glycol di(meth)acrylate and 1,3-butanediol di(meth)acrylate, tri(meth)acrylate, allyl carboxylate such as allyl acrylate and allyl methacrylate, and diallyl and triallyl compounds such as diallyl phthalate, diallyl sebacate, and triallyl triazine.

[0061] According to a preferred embodiment, the functionalized core-shell packing comprises:

[0062] - A core comprising a core polymer (or consisting substantially of a core polymer), said core polymer comprising butadiene homopolymer (or consisting substantially of butadiene homopolymer).

[0063] - A shell comprising a shell polymer (or substantially composed of a shell polymer), said shell polymer comprising a methyl methacrylate polymer (or substantially composed of a methyl methacrylate polymer), particularly said methyl methacrylate polymer comprising at least 70% by weight, relative to the total weight of said polymer, repeating units derived from methyl methacrylate, and

[0064] - Optionally, one or more intermediate polymer layers, each layer comprising (or consisting substantially of) an intermediate polymer, said intermediate polymer comprising (or consisting substantially of) a methyl methacrylate polymer, particularly said methyl methacrylate polymer comprising at least 70% by weight, relative to the total weight of said polymer, repeating units derived from methyl methacrylate.

[0065] At least one of the shell polymers and optionally the intermediate polymers contains a carboxamide group and / or a cycloalkyl ester group, preferably C8-C. 12 Cycloalkyl ester groups, particularly isobornyl, 3,3,5-trimethylcyclohexyl, tert-butylcyclohexyl and / or (octahydro-4,7-methylene-1H-indenyl)methyl ester groups, especially isobornyl ester groups.

[0066] The volume average diameter of the functionalized core-shell filler can be between 10 nm and 900 nm, preferably between 20 nm and 700 nm, and more preferably between 20 nm and 500 nm. The volume average diameter can be measured by dynamic light scattering (DLS).

[0067] The content of the functionalized core-shell filler relative to the total weight of the composition according to the invention may be between 1% by weight and 30% by weight, preferably between 2% by weight and 20% by weight, and more preferably between 3% by weight and 10% by weight.

[0068] (meth)acrylate polymers

[0069] The compositions according to the invention comprise a (meth)acrylate polymer selected from urethane (meth)acrylate polymers, polyester (meth)acrylate polymers, epoxy (meth)acrylate polymers, and mixtures thereof, preferably a (meth)acrylate polymer selected from urethane (meth)acrylate polymers. Preferably, the (meth)acrylate polymer is a (meth)acrylate oligomer selected from urethane (meth)acrylate oligomers, polyester (meth)acrylate oligomers, epoxy (meth)acrylate oligomers, and mixtures thereof, more preferably a (meth)acrylate oligomer selected from urethane (meth)acrylate oligomers.

[0070] The term “oligomer” is known to those skilled in the art and can be defined as a small polymer, for example, containing 2 to 30 repeating units.

[0071] Advantageously, the (meth)acrylate polymer contains between two and six (meth)acrylate groups, preferably exactly two (meth)acrylate groups. Preferably, the (meth)acrylate polymer is an acrylate polymer.

[0072] (Meth)acrylate polymers may have a number average molecular weight between 500 g / mol and 20,000 g / mol, preferably between 700 g / mol and 10,000 g / mol, for example between 800 g / mol and 6,500 g / mol. The number average molecular weight can be determined by size exclusion chromatography (SEC), for example using a poly(meth)acrylate reference standard and tetrahydrofuran as a solvent.

[0073] (Meth)acrylate polymers 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. Tg can be determined by dynamic mechanical analysis (DMA), particularly as the temperature at which the maximum value of the tan δ peak is observed. It can preferably be measured on an HR20 device (TA Instruments) with a temperature ramp range of -50°C to 100°C, a heating rate of 3°C / min, and a deformation of 0.05% under rectangular torsion at a frequency of 10 Hz.

[0074] There are many commercially available (meth)acrylate polymers, especially those from Sartomer.

[0075] urethane (meth)acrylate polymers

[0076] The urethane (meth)acrylate polymer can be obtained by reacting a polyol (preferably a diol) and a polyisocyanate (preferably a diisocyanate) to form one or more urethane bonds (-OC(=O)-NH-), followed by functionalization with (meth)acrylate.

[0077] The polyol may be aliphatic or aromatic, preferably aliphatic. The polyol may be polyether polyol (e.g., polyethylene glycol, polypropylene glycol) and / or polyester polyol, preferably polyester polyol.

[0078] Polyisocyanates can be aliphatic or aromatic, with aliphatic being preferred.

[0079] The (meth)acrylate used for functionalization may be a hydroxyalkyl (meth)acrylate, such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxypentyl (meth)acrylate, and / or hydroxyhexyl (meth)acrylate. The (meth)acrylate is preferably an acrylate.

[0080] Polyester (meth)acrylate polymers

[0081] Polyester (meth)acrylate polymers can be obtained by reacting a polycarboxylic acid (preferably a dicarboxylic acid) with a polyol (preferably a diol) to form a polyester polyol (preferably a polyester diol) having several ester bonds, followed by esterification with (meth)acrylate.

[0082] Polyester polyols can be aliphatic or aromatic, with aliphatic being preferred.

[0083] Epoxy (meth)acrylate polymers

[0084] Epoxy (meth)acrylate polymers can be obtained by esterification of polyepoxide polymers, preferably diepoxide polymers, with (meth)acrylate.

[0085] The polyepoxide polymer can be aliphatic or aromatic, with aliphatic being preferred.

[0086] For example, the polyepoxide polymer can be polyepoxide polybutadiene and / or polyepoxide polyunsaturated oil.

[0087] The content of (meth)acrylate polymer relative to the total weight of the composition according to the invention may be between 5% by weight and 50% by weight, preferably between 6% by weight and 40% by weight, and more preferably between 7% by weight and 30% by weight.

[0088] Photoinitiator

[0089] The composition according to the invention comprises a photoinitiator that enables the generation of free radicals upon exposure to electromagnetic (preferably UV) radiation, which will be responsible for initiating a photocrosslinking reaction. The photoinitiator is selected, of course, based on its ability to effectively absorb selected radiation as a function of the radiation source used.

[0090] Advantageously, photoinitiators are suitable for use with irradiation sources that emit light in the UV-visible region, particularly at wavelengths between 100 nm and 800 nm. For example, UV-visible radiation sources could be iron-doped mercury-type LEDs or UVA-centered broad-spectrum lamps (wavelengths between 315 nm and 400 nm).

[0091] The photoinitiator can be selected from type I photoinitiators, type II photoinitiators, and mixtures thereof, with type I photoinitiators being preferred. Type I and type II photoinitiators are known to those skilled in the art. In particular, type I photoinitiators undergo unimolecular bond breaking upon irradiation to generate free radicals, while type II photoinitiators undergo a bimolecular reaction in which the excited state of the photoinitiator interacts with a second molecule (co-initiator) to generate free radicals.

[0092] Type I photoinitiator

[0093] Type I photoinitiators can be selected from:

[0094] -Acetophenone,

[0095] -Alkoxyacetophenone (e.g., 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, 4′-ethoxyacetophenone), preferably α-dialkoxyacetophenone,

[0096] -Hydroxyalkyl phenyl ketones (e.g., 3′-hydroxyacetophenone, 4′-hydroxyacetophenone, 2,2-dimethyl-2-hydroxyacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylphenylpropanone, 2-hydroxy-2-methylphenylpropanone), preferably α-hydroxyalkyl phenyl ketones.

[0097] -Aminoalkylphenyl ketones (e.g., 2-methyl-4'-(methylthio)-2-morpholinophenylacetone, 2-benzyl-2-(dimethylamino)-4'-morpholinophenylbutanone, 2-(4-(methylbenzyl)-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone), preferably α-aminoalkylphenyl ketones,

[0098] -Phenylacetin ethers (e.g., benzoylacetin methyl ether, benzoylacetin ethyl ether, benzoylacetin isopropyl ether, benzoylacetin isobutyl ether),

[0099] Phosphine oxides (e.g., diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO), ethyl (2,4,6-trimethylbenzoyl)phenylphosphine sulfate (TPO-L, CAS: 84434-11-7), phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide (BAPO, CAS: 162881-26-7), preferably acylphosphine oxides),

[0100] - Metallocenes (e.g., ferrocene, bis[2,6-difluoro-3-(1H-pyrrolo-1-yl)phenyl]titanium bis( ...

[0101] -Benzylan and its derivatives (e.g., 4,4'-dimethylbenzoyl),

[0102] - and its mixtures.

[0103] Advantageously, the type I photoinitiator is selected from α-hydroxyalkylphenyl ketone, acylphosphine oxide and mixtures thereof, and particularly from mixtures of hydroxyalkylphenyl ketone and acylphosphine oxide photoinitiators.

[0104] Type II photoinitiator

[0105] Type II photoinitiators can be selected from:

[0106] - Benzophenones (e.g., benzophenone, 4-phenylbenzophenone, 4-(4-methylphenylthio)benzophenone, 1-[4-[(4-benzoylphenyl)thio]phenyl]-2-methyl-2-[(4-methylphenyl)sulfonyl]-1-propanone (CAS: 272460-97-6)),

[0107] -Thioxanthone (e.g., isopropylthioxanthone (ITX), 2,4-diethylthioxanthone, 2,4-dimethylthioxanthone, 2-chlorothioxanthone, 1-chloro-4-isopropylthioxanthone),

[0108] -Phenylacetyl esters (e.g., methyl phenylglyoxylate),

[0109] -Dibenzyl ketones (e.g., 1,5-bis[4-(dimethylamino)phenyl]-1,4-pentadien-3-one),

[0110] -Coumarins (e.g., coumarin, 7-methoxycoumarin, 7-diethylaminocoumarin),

[0111] - and its mixtures.

[0112] The content of the photoinitiator may be between 0.1% by weight and 5% by weight relative to the total weight of the composition according to the invention, preferably between 0.5% by weight and 4% by weight, and more preferably between 0.8% by weight and 3% by weight.

[0113] Adhesion promoter

[0114] Advantageously, the compositions according to the invention also contain an adhesion promoter.

[0115] The adhesion promoter may be selected from silanes (e.g., aminosilanes, epoxysilanes, acryloylsilanes), phosphate-based adhesion promoters (e.g., monoesters, diesters, and trimers of 2-hydroxyethyl phosphate of (meth)acrylate), (meth)acrylate, (meth)acrylamide (preferably N,N-dialkylamides of (meth)acrylate, such as N,N-dimethylacrylamide), metal salts of di(meth)acrylate (e.g., zinc di(meth)acrylate, calcium di(meth)acrylate, magnesium di(meth)acrylate), and mixtures thereof, preferably selected from (meth)acrylate, N,N-dialkylamides of (meth)acrylate, and mixtures thereof, particularly mixtures of acrylic acid, methacrylic acid, and N,N-dimethylacrylamide.

[0116] Advantageously, the adhesion promoter contains at least 60% by weight (meth)acrylamide (especially N,N-dimethylacrylamide), preferably at least 70% by weight, more preferably at least 80% by weight, relative to the total weight of the adhesion promoter.

[0117] The content of the adhesion promoter may be between 5% and 25% by weight, preferably between 10% and 20% by weight, and more preferably between 12% and 18% by weight, relative to the total weight of the composition according to the invention.

[0118] Acrylic block copolymers

[0119] The compositions according to the present invention may further comprise acrylic block copolymers.

[0120] "Acrylic block copolymer" should be understood to mean a block copolymer containing at least one acrylic block, that is, containing at least one block composed of a polymer obtained from at least one acrylic monomer. "Acrylic monomer" should be understood to specifically mean a monomer containing a group of the formula -X-(C=O)-C(R)=CH2, where R represents a hydrogen atom or a methyl group, and -X- represents -O- or -NR'-, where R' represents a hydrogen atom or an alkyl group containing 1 to 22 carbon atoms, preferably 1 to 14 carbon atoms, more preferably 1 to 8 carbon atoms (cyclic, linear, or branched). Preferably, -X- represents -O-.

[0121] "Block copolymer" should be understood as a copolymer containing polymer blocks, that is, a sequence of polymers that are chemically different from each other and are linked together by covalent bonds.

[0122] Advantageously, the acrylic block copolymer is not obtained from styrene; preferably, the acrylic block copolymer comprises only (meth)acrylic blocks (that is, all its blocks are obtained from (meth)acrylic monomers), more preferably only (meth)acrylic alkyl ester blocks, each block optionally further comprising one or more monomers selected from: (meth)acrylic acid, (meth)acrylamide (preferably dialkyl (meth)acrylamide, such as N,N-dimethylacrylamide), amino (meth)acrylic ester (preferably (meth)acrylic ester containing a primary amine, such as 2-aminoethyl (meth)acrylic acid), epoxy (meth)acrylic ester (e.g., glycidyl (meth)acrylic acid), hydroxy (meth)acrylic ester (e.g., polyethylene glycol (meth)acrylic acid), alkoxy (meth)acrylic ester (e.g., 2-methoxyethyl (meth)acrylic acid) and mixtures thereof.

[0123] Advantageously, the acrylic block copolymer comprises at least one block A and at least one block B, wherein block A is a polymer containing methyl methacrylate monomer (that is, methyl methacrylate is the only monomer or one of the monomers used to obtain the polymer), and block B is a polymer that does not contain any methyl methacrylate monomer. Preferably, the acrylic block copolymer is an AB diblock copolymer or an ABA triblock copolymer (where the two A blocks are obtained from the same or different monomers), more preferably an ABA triblock copolymer.

[0124] Preferably, block A is a polymer obtained from a monomer mixture containing at least 50% by weight of methyl methacrylate relative to the total weight of the monomer mixture, more preferably at least 75% by weight.

[0125] It should be understood that a “monomer mixture” refers to a mixture consisting of one or more monomers; therefore, when calculating the total weight of a monomer mixture, components other than the monomers (such as solvents, surfactants, etc. used during polymerization) are not considered.

[0126] When block A is a methyl methacrylate copolymer, the other monomers constituting the copolymer may be selected from methyl acrylate, ethyl methacrylate, methacrylic acid, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, pentyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, methacrylamide (preferably dialkyl (meth)acrylamide, such as N,N-dimethylacrylamide), 2-methoxyethyl methacrylate, 2-aminoethyl methacrylate, glycidyl methacrylate, polyethylene glycol (meth)acrylate (PEG(meth)acrylate), wherein the molar mass of the PEG group ranges from 400 to 10,000 g / mol, and mixtures thereof.

[0127] Preferably, block B is a polymer having a glass transition temperature (Tg) of less than 0°C, more preferably less than -20°C. Tg can be measured by differential scanning calorimetry (DSC).

[0128] Block B may be a polymer obtained from a monomer mixture comprising at least 50% by weight of one or more monomers selected from ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, hydroxyethyl acrylate, 2-ethylhexyl methacrylate, and mixtures thereof, preferably at least 50% by weight of n-butyl acrylate, more preferably at least 75% by weight of n-butyl acrylate, relative to the total weight of the monomer mixture.

[0129] The content of the acrylic block copolymer relative to the total weight of the composition according to the invention can be up to 30% by weight, preferably up to 20% by weight, and more preferably up to 10% by weight.

[0130] additive

[0131] The compositions according to the invention may further comprise one or more additives selected from crosslinking agents, fillers (other than the functionalized core-shell fillers), heat stabilizers, UV stabilizers (or antioxidants), ultraviolet or infrared fluorescent agents, dispersants, plasticizers, rheology modifiers, solvents, hygroscopic agents, and mixtures thereof.

[0132] Advantageously, the compositions according to the invention comprise a mixture of additives selected from rheology modifiers and hygroscopic agents.

[0133] The total content of the additives relative to the total weight of the composition according to the invention can range up to 30% by weight, preferably between 1% and 20% by weight.

[0134] The crosslinking agent may be a polyfunctional (meth)acrylate, preferably a polyfunctional acrylate. For example, the crosslinking agent may be selected from polyethylene glycol dimethacrylate (e.g., diethylene glycol dimethacrylate, triethylene glycol dimethacrylate and / or tetraethylene glycol dimethacrylate), polypropylene glycol dimethacrylate (e.g., dipropylene glycol dimethacrylate), hexanediol dimethacrylate, trimethylolpropane trimethacrylate, tetramethylene glycol dimethacrylate, di(pentamethylene glycol) dimethacrylate, ethylene dimethacrylate, bisphenol A dimethacrylate, bisphenol F dimethacrylate, and mixtures thereof.

[0135] The content of the crosslinking agent may be up to 5% by weight relative to the total weight of the composition according to the invention.

[0136] The packing material can be selected from organic packing materials, mineral packing materials, and mixtures thereof.

[0137] As an example of mineral fillers, any mineral filler conventionally used in the field of adhesive compositions may be mentioned. These fillers are typically in the form of particles of various geometries. They may be, for example, spherical or fibrous or exhibit irregular shapes.

[0138] Mineral fillers may be selected from clay (such as talc), quartz, carbonate fillers (especially calcium carbonate, which may be coated with fatty acids (the calcium carbonate is preferably precipitated)), kaolin, gypsum, hollow mineral microspheres (especially hollow glass microspheres, such as those made of sodium calcium borosilicate or aluminosilicate), zeolite and mixtures thereof.

[0139] Mineral fillers can be untreated or treated, for example, using organic acids containing stearic acid.

[0140] The average particle size of the mineral filler can range from 10 nm to 400 μm, preferably from 20 nm to 100 μm, and more preferably from 30 nm to 50 μm.

[0141] In this specification, the average particle size advantageously corresponds to the d50 particle size, that is, the maximum size of the smallest particle by volume of 50%, and can be measured by a particle size analyzer, in particular by laser diffraction on a Malvern apparatus (e.g., according to standard ISO 13320).

[0142] As an example of organic fillers, any organic filler commonly used in the field of adhesive compositions, especially polymer fillers, may be mentioned.

[0143] Organic fillers can be selected from polyvinyl chloride (PVC), polyolefins, ethylene-vinyl acetate (EVA), expandable or non-expandable hollow thermoplastic polymer microspheres (e.g., hollow vinylidene chloride / acrylonitrile microspheres), and aromatic polyamide fibers (e.g., Kevlar® and mixtures thereof).

[0144] The average particle size of the organic filler can be less than or equal to 50 μm, preferably between 5 and 20 μm.

[0145] The filler content can range up to 10% by weight relative to the total weight of the composition according to the invention.

[0146] The heat stabilizer can be selected from hydroquinone, methylhydroquinone, 2,6-di-tert-butyl-4-methoxyphenol, and 2,4-dimethyl-6-tert-butylphenol (Topanol A).

[0147] The content of the heat stabilizer relative to the total weight of the composition according to the invention can range up to 3% by weight.

[0148] UV stabilizers are typically introduced to prevent degradation caused by reactions with oxygen, which may occur through the action of heat or light. UV stabilizers may include antioxidants capable of scavenging free radicals.

[0149] UV stabilizers (or antioxidants) can be selected from benzotriazoles, benzophenones, triazines (e.g., hydroxyphenyltriazine, especially mixtures of 2-[4-[2-hydroxy-3-tetaneoxypropyl]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 (e.g., tris(2,4-di-tert-butylphenyl) phosphite), hindered phenols (e.g., ethylene bis(oxyethylene)bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate], 2,2'-methylene bis(6-(tert-butyl)-4-methylphenol), 2,2'-methylene bis(6-(tert-butyl)-4-ethylphenol), 2,2'-methylene bis(4-methyl-6-cyclohexylphenol), 2,2'-methylene bis(4,6-di(tert-butyl)phenol), 4,4'-methylene bis(2,6-di(tert-butyl)phenol, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), 2,6-Di(tert-butyl)-4-methylphenol, hindered amines (e.g., bis(1-octoxy-2,2,6,6-tetramethyl-4-piperidinyl) sebacate, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate (CAS No.: 41556-26-7), methyl 1,2,2,6,6-pentamethyl-4-piperidinyl sebacate (CAS No.: 82919-37-7), 4,4'-bis(α,α-dimethylbenzyl)diphenylamine), and mixtures thereof.

[0150] The content of UV stabilizer (or antioxidant) may be up to 3% by weight relative to the total weight of the composition according to the invention.

[0151] For example, the ultraviolet or infrared fluorescent agent can be 2,5-thiophenedimethylbis(5-tert-butyl-1,3-benzoxazole).

[0152] The content of ultraviolet or infrared fluorescent agent may be up to 3% by weight relative to the total weight of the composition according to the invention.

[0153] For example, dispersants can be selected from polycarboxylic acid polymers (especially maleic acid copolymers), polyhydroxycarboxylic amides (e.g., gluconic acid amide, glucoheponic acid amide), and mixtures thereof. Commercial examples of dispersants are Rheobyk-405 and BYK-P 105 supplied by BYK.

[0154] The content of the dispersant relative to the total weight of the composition according to the invention can range up to 5% by weight.

[0155] The plasticizer can be any plasticizer commonly used in the field of adhesives.

[0156] For example, plasticizers may be selected from epoxy resins (such as those based on bisphenol A diglycidyl ether), alkyl phthalates (such as diisodecyl phthalate, diisononyl phthalate, and diisononyl hexahydrophthalate), benzoates (such as nonyl benzoate), esters of alkyl sulfonic acids and phenols (such as Mesamoll® provided by Lanxess), pentaerythritol tetravalve ester, diisononyl 1,2-cyclohexanedicarboxylate, 3,3'-methylenebis(oxymethylene)]bis[heptane], dioctyl carbonate, hydrocarbon oils (also known as mineral oils, typically derived from petroleum, such as paraffin oil and naphthenic oil), natural oils (which may optionally be epoxidized, such as epoxidized soybean oil), polypropylene, polybutene, hydrogenated polyisoprene, and mixtures thereof.

[0157] The content of plasticizer relative to the total weight of the composition according to the invention can range up to 8% by weight.

[0158] The rheology modifier may be a self-thixotropic agent, for example selected from:

[0159] - PVC plastisols, corresponding to suspensions of PVC in PVC-miscible plasticizers, are obtained in situ by heating at temperatures ranging from 60°C to 80°C. These plastisols are particularly those described in the publication "Polyurethane Sealants," Robert M. Evans, ISBN 087762-998-6.

[0160] - Fumed silica (preferably hydrophobic),

[0161] - Urea derivatives produced by the reaction of a diisocyanate monomer with an aliphatic primary amine, wherein the diisocyanate monomer is preferably aromatic, such as methylene diphenyl diisocyanate (especially 4,4'-MDI), and the aliphatic primary amine is such as butylamine.

[0162] - Waxes derived from castor oil, such as THIXCIN® R supplied by Elementis.

[0163] -Amide waxes, preferably micronized, such as CRAYVALLAC® SLT supplied by Arkema, and

[0164] - Its mixture.

[0165] "Waxes derived from castor oil" should be understood as waxes obtained from castor oil (especially hydrogenated castor oil).

[0166] "Amide wax" should be understood to mean a wax containing one or more compounds having at least one amide group. In particular, amide waxes can be obtained from organic acids (e.g., fatty acids) and (di)amines.

[0167] The amide waxes are preferably micronized, meaning 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, and more preferably less than 10 μm.

[0168] Preferably, the rheology modifier is fumed silica, more preferably hydrophobic fumed silica.

[0169] The total content of rheology modifier relative to the total weight of the composition according to the invention can range up to 20% by weight, preferably between 3% and 15% by weight.

[0170] The solvent may be any solvent suitable for use in acrylic adhesive compositions.

[0171] The solvent content can range up to 5% by weight relative to the total weight of the composition according to the invention.

[0172] The hygroscopic agent may be an alkoxysilane, such as a trialkoxysilane, particularly a trimethoxysilane. For example, the hygroscopic agent may be selected from vinyltrimethoxysilane, trimethoxymethylsilane, propyltrimethoxysilane, vinyltriethoxysilane, alkoxyarylsilane (such as GENIOSIL® XL 70 sold by Wacker) and mixtures thereof, particularly vinyltrimethoxysilane.

[0173] The total content of the desiccant relative to the total weight of the composition according to the invention can range up to 5% by weight, preferably between 0.5% by weight and 4% by weight.

[0174] Other features of the compositions according to the invention

[0175] The compositions according to the invention may be single-component or two-component, preferably single-component.

[0176] Advantageously, the compositions according to the invention comprise less than 1% by weight, preferably less than 0.1% by weight, more preferably less than 0.01% by weight, of a reducing agent selected from tertiary amines derived from p-toluidine (e.g., 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), and aniline-derived amines. Tertiary amines (e.g., 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-chloroaniline, N,N-diethyl-p-bromoaniline), N,N-dimethylaminomethylphenol, and mixtures thereof.

[0177] According to one embodiment, the composition according to the invention comprises:

[0178] - Monofunctional (meth)acrylate monomers between 20% and 80% by weight, said monomers preferably comprising at least 40% by weight of cycloalkyl acrylates relative to the total weight of said monomers.

[0179] - Functionalized core-shell fillers between 1% and 30% by weight, wherein the fillers preferably comprise a shell polymer and optionally one or more intermediate polymers, wherein at least one of the shell polymer and optional intermediate polymers comprises a functional group selected from epoxy groups, carboxylic acid groups, carboxamide groups, alkoxy groups, amine groups, cycloalkyl ester groups, and mixtures thereof.

[0180] - A (meth)acrylate polymer selected from urethane (meth)acrylate polymers, polyester (meth)acrylate polymers, epoxy (meth)acrylate polymers, and mixtures thereof, preferably selected from urethane (meth)acrylate polymers.

[0181] - Photoinitiators between 0.1 wt% and 5 wt%,

[0182] - Adhesion promoters between 5% and 25% by weight

[0183] -Optional up to 30% by weight of acrylic block copolymers

[0184] -Optionally up to 30% by weight of one or more additives selected from crosslinking agents, fillers (other than the functionalized core-shell fillers), heat stabilizers, UV stabilizers (or antioxidants), ultraviolet or infrared fluorescent agents, dispersants, plasticizers, rheology modifiers, solvents, hygroscopic agents, and mixtures thereof.

[0185] Unless otherwise stated, weight percentages are relative to the total weight of the composition according to the invention.

[0186] Preferably, the composition according to the invention is substantially composed of the above-described components. "Substantially composed of" should be understood to mean that, relative to the total weight of the composition, the composition according to the invention contains less than 5% by weight, preferably less than 2% by weight, and even more preferably less than 1% by weight of components other than the above-described components.

[0187] The components and their specific contents of this embodiment are as described above, including preferred features and embodiments.

[0188] Specifically, the composition according to the invention comprises:

[0189] - A monofunctional (meth)acrylate monomer comprising, between 40 wt% and 60 wt% relative to the total weight of the monomer, preferably at least 40 wt% of isobornyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, tert-butylcyclohexyl acrylate and / or (octahydro-4,7-methylene-1H-indenyl)methyl acrylate.

[0190] - Functionalized core-shell fillers between 3% and 10% by weight, wherein the fillers preferably comprise a shell polymer and optionally one or more intermediate polymers, wherein at least one of the shell polymer and optional intermediate polymers comprises carboxamide and / or cycloalkyl ester groups.

[0191] - A (meth)acrylate polymer selected from urethane (meth)acrylate polymers, polyester (meth)acrylate polymers, epoxy (meth)acrylate polymers, and mixtures thereof, preferably selected from urethane acrylate oligomers.

[0192] - Photoinitiators between 0.8 wt% and 3 wt%, preferably type I photoinitiators.

[0193] - Adhesion promoters ranging from 12% to 18% by weight, preferably comprising at least 60% by weight (meth)acrylamide relative to the total weight of the adhesion promoters.

[0194] -Optional up to 10% by weight of acrylic block copolymers,

[0195] -Optionally, in amounts between 1% and 20% by weight, one or more additives selected from crosslinking agents, fillers (other than the functionalized core-shell fillers), heat stabilizers, UV stabilizers (or antioxidants), ultraviolet or infrared fluorescent agents, dispersants, plasticizers, rheology modifiers, solvents, hygroscopic agents, and mixtures thereof.

[0196] Unless otherwise stated, weight percentages are relative to the total weight of the composition according to the invention.

[0197] Preferably, the composition according to the invention consists essentially of the above-described components.

[0198] The components and their specific contents of this embodiment are as described above, including preferred features and embodiments.

[0199] Advantageously, the compositions according to the invention have a shear strength in polycarbonate of at least 7 MPa, preferably between 7 MPa and 12 MPa. The shear strength can be measured according to standard ISO 4587 (2003), for example as shown in Example 1 below.

[0200] The compositions according to the invention can be prepared by simply mixing their components. Preparation examples are described in Example 2 below.

[0201] Use of the composition according to the invention

[0202] The present invention also relates to the use of the compositions according to the invention as adhesives, coatings, UV inks or in 3D printing, preferably as adhesives, particularly in the field of building construction, and in the manufacture of transportation vehicles (e.g., automotive, railroad, aerospace or naval industries), electronic products, luxury goods or medical products (e.g. perfume bottles, wine bottles, cosmetic displays or dental product assembly).

[0203] The compositions according to the present invention are as described above, including preferred features and embodiments.

[0204] Method for assembling substrates

[0205] The present invention also relates to a method for assembling a substrate, comprising:

[0206] - The composition according to the invention, as described above (including preferred features and embodiments), is applied to at least one surface of the substrate to be assembled, and then...

[0207] -Make the substrate come into contact, and then

[0208] - To crosslink the composition.

[0209] It should be understood that the composition according to the invention is in a non-crosslinked state during the coating and contacting steps.

[0210] The crosslinking step can be carried out at a temperature between 10°C and 40°C, preferably between 15°C and 30°C, especially at ambient temperatures (e.g., 18°C ​​to 25°C).

[0211] The crosslinking step can be performed under electromagnetic irradiation with wavelengths between 100 nm and 680 nm, preferably between 315 nm and 420 nm, and more preferably between 360 nm and 410 nm.

[0212] The crosslinking step under electromagnetic irradiation can be performed using a UV radiation source, preferably an LED.

[0213] The substrates can be the same or different.

[0214] A variety of substrates can be used. These can be, for example, plastics, glass, metals, and / or composites. Preferably, at least one substrate is plastic; more preferably, the substrate is plastic.

[0215] 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, especially polycarbonate.

[0216] The metal can be pure or an alloy, such as aluminum or steel (including stainless steel).

[0217] The composite can be a reinforcing plastic material, such as fiber-reinforced plastics, particularly sheet molding composites (SMCs). The fibers in the fiber-reinforced plastic can be glass fibers, carbon fibers, aramid fibers, or basalt fibers, preferably glass fibers. The fiber length can vary between 6 mm and 50 mm. The polymer in the reinforcing plastic material can be polyester, polyolefin, epoxy resin, or vinyl ester resin. The polymer present in the reinforcing plastic material is preferably unsaturated. The reinforcing plastic material may contain compounds other than fibers and polymers (e.g., fillers and / or catalysts).

[0218] Products

[0219] The present invention also relates to articles comprising, as described above (including preferred features and embodiments) of a composition according to the invention (in a cross-linked or non-cross-linked state), said composition bonding at least two substrates of said article.

[0220] The article can be obtained by the method for assembling a substrate according to the present invention (including preferred features and embodiments).

[0221] The substrate is preferably as described above for the method of assembling the substrate according to the invention; in particular, the substrate is preferably made of plastic, especially polycarbonate.

[0222] All of the above embodiments can be combined with each other. In particular, the various components of the composition described above, especially the preferred embodiments, can be combined with each other.

[0223] The following examples are given only to illustrate the invention and should not be construed as limiting its scope.

[0224] Example

[0225] Example 1 Composition and Measurement Methods

[0226] Ingredients used

[0227] Use the following ingredients:

[0228] -SR506D: Isoborneol Acrylate, sold by Sartomer

[0229] -NNDMA: N,N-dimethylacrylamide, adhesion promoter.

[0230] - SR489: Tridecyl Acrylate, sold by Sartomer

[0231] -Core-Shell A: Isoborneol-functionalized polybutadiene-poly(methyl methacrylate) core-shell filler

[0232] -Core-shell B: N,N-dimethylacrylamide-functionalized polybutadiene-poly(methyl methacrylate) core-shell filler

[0233] -Core-shell C: Non-functionalized polybutadiene-poly(methyl methacrylate) core-shell filler

[0234] -AA: Icy acrylic acid, adhesion promoter

[0235] -MAA: Methacrylic acid, adhesion promoter.

[0236] - CN966H90 sold by Sartomer: polyester-based aliphatic urethane diacrylate oligomers, which are mixtures having 10% by weight of 2-(2-ethoxyethoxy)ethyl acrylate relative to the total weight of the mixture.

[0237] - SpeedCure 2100, sold by Sartamomer: a mixture of ethyl (2,4,6-trimethylbenzoyl)phenylphosphine oxide (CAS: 84434-11-7) and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (CAS: 162881-26-7), a photoinitiator.

[0238] - Omnirad 1173: 2-hydroxy-2-methylphenylacetone, a photoinitiator, sold by IGM Resins.

[0239] JH-V171: Vinyltrimethoxysilane, a hygroscopic agent, sold by Jingzhou Jianghan Fine Chemical.

[0240] - AEROSIL® R 812 S sold by Evonik: hydrophobic fumed silica (treated with hexamethyldisilazane), rheology modifier.

[0241] Preparation of core-shell A

[0242] Core-shell filler A is in the form of a multi-stage core-shell polymer comprising a core and two shells, and is prepared according to the method described for core / shell filler-2 in WO2020 / 260638, except that 30% by weight of MMA is replaced with isobornyl acrylate in the synthesis of the two shells. The volume average diameter of the particles after multi-stage polymerization is approximately 170 nm (measured by dynamic light scattering using a Zetasizer from Malvern). The obtained product is coagulated with sulfuric acid and dried.

[0243] Preparation of core-shell B

[0244] The preparation of core-shell packing material B is described below for core-shell packing material C, except that in the second step B, N,N-dimethylacrylamide (DMA) is used instead of 2.26 parts of MMA.

[0245] Preparation of core-shell C

[0246] Step A - Polymerization of Polymer A1: A 20°C pressurized reactor was initially charged with 116.5 parts deionized water, 0.1 parts potassium tallow fatty acid emulsifier, 21.9 parts 1,3-butadiene, 0.1 parts tert-dodecyl mercaptan, and 0.1 parts p-menthane hydroperoxide. The solution was heated to 43°C with stirring, at which point a redox catalyst solution (4.5 parts water, 0.3 parts tetrasodium pyrophosphate, 0.004 parts ferrous sulfate, and 0.3 parts dextrose) was added to effectively initiate polymerization. Subsequently, the solution was further heated to 56°C and maintained at this temperature for three hours. Three hours after polymerization initiation, a second monomer feed (77.8 parts of 1,3-butadiene, 0.2 parts of tert-dodecyl mercaptan), half of the remaining emulsifying and reducing charge (30.4 parts of deionized water, 2.8 parts of tallow fatty acid potassium salt emulsifier, 0.5 parts of dextrose), and the remaining initiator (0.8 parts of p-menthane hydroperoxide) were added over an additional five hours. After the second monomer addition was complete, the remaining emulsifying and reducing charge and initiator were added over another five hours. Thirteen hours after polymerization initiation, the solution was heated to 68°C and allowed to react until at least [number] hours had elapsed since polymerization initiation, producing polybutadiene rubber latex R1. The resulting polybutadiene rubber latex (A1) contained 38% solids and had a weight-average particle size of approximately 160 nm.

[0247] Step B - Polymerization of Polymer B1: 75.0 parts (based on solids) of polybutadiene rubber latex R1, 37.6 parts of deionized water, and 0.1 parts of sodium formaldehyde sulfoxylate were charged into a 3.9-liter reactor. 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 parts of tert-butyl hydroperoxide initiator was continuously added over a 70-minute process, followed by a hold of 80 minutes. Thirty minutes after the start of the hold period, 0.1 parts of sodium formaldehyde sulfoxylate and 0.1 parts of tert-butyl hydroperoxide were added to the reactor all at once. After an 80-minute hold period, the stabilized emulsion was added to the graft copolymer latex. A stable emulsion was prepared by mixing 3.2 parts of deionized water (based on the mass of the graft copolymer), 0.1 parts of oleic acid, 0.1 parts of potassium hydroxide, and 0.9 parts of octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate. The resulting core-shell polymer (A1+B1) had a weight-average particle size of approximately 180 nm.

[0248] Step C - Polymerization of Polymer C1 (semi-continuous process): 10,000 g of the core-shell polymer (A1+B1) still dispersed in deionized water, 0.01 g of FeSO4 and 0.032 g of sodium ethylenediaminetetraacetate (dissolved in 10 g of deionized water), 3.15 g of sodium formaldehyde bisulfite (dissolved in 110 g of deionized water), and 21.33 g of tallow fatty acid potassium salt emulsifier (dissolved in 139.44 g of water) were added to a stirred reactor and the mixture was stirred until the added raw materials (except the core-shell polymer) were completely dissolved. The reactor was then subjected to three consecutive vacuum-nitrogen purgings and placed under a slight vacuum. The reactor was then heated. Simultaneously, a mixture containing 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. Subsequently, the monomer mixture was introduced into the reactor using a pump over a process of 180 minutes. Simultaneously, a solution of 5.33 g of tert-butyl hydroperoxide (dissolved in 100 g of deionized water) was introduced (at the same addition time). The pipeline was flushed with 50 g and 20 g of water. Subsequently, the reaction mixture was heated to 80°C, and polymerization was allowed to proceed for 60 minutes until completion after the monomer addition was finished. The reactor was then cooled to 30°C.

[0249] The core-shell packing material C(A1+B1+C1) was then collected in powder form by spray drying.

[0250] Lap shear strength (LSS)

[0251] The lap shear strength was measured according to standard ISO 4587 (2003). A 250 μm thick assembly was applied between two 4 mm thick polycarbonate sheets at approximately 23 °C. The lap shear strength was measured 24 h after irradiation of the assembly with an LED centered at 385 nm for 30 seconds at 23 °C, with the LED positioned at a distance of 8 cm. The lap shear stress was applied at a constant rate of 5 mm / min using a tensile testing machine.

[0252] "Approximately X" is intended to indicate that the value of X is added to or subtracted by 10%.

[0253] transparency

[0254] For assemblies made between two glass sheets in the same manner as the lap shear strength test, the transparency is visually evaluated.

[0255] Example 2 Preparation of the composition according to the present invention and the comparative composition

[0256] Compositions were prepared using the ingredients shown in Table 1, with values ​​for each composition representing weight percentages relative to the total weight of the composition. For compositions containing core-shell packing, the packing was first dispersed in a portion of CN966H90 at atmospheric pressure using a deflocculating impeller (to obtain a packing concentration between 20% and 60% by weight relative to the total weight of the packing and CN966H90); friction raised the temperature of the mixture to approximately 60°C. Subsequently, the remaining CN966H90 was introduced and stirring continued until no particles remained. The remaining ingredients were then added and stirring continued until homogenized.

[0257] Table 1

[0258]

[0259] Example 3 Properties of the composition prepared in Example 2

[0260] The properties of the composition prepared in Example 2 were evaluated according to the method described in Example 1.

[0261] The results are given in the following table:

[0262]

[0263] The addition of nonfunctionalized core-shell filler increases the lap shear strength (comparison of compositions 1 and 2).

[0264] In addition, composition 4 according to the present invention has the advantage of being more transparent than comparative composition 2.

[0265] Compositions 3 and 4 comprise monofunctional (meth)acrylate monomers, said monofunctional (meth)acrylate monomers comprising cyclic alkyl acrylates and acyclic alkyl acrylates. Comparative composition No. 5 comprises only isobornyl acrylate (SR506D).

[0266] Compared to composition 5, which has a lower lap shear strength (3.2 MPa), compositions 3 and 4 advantageously have an lap shear strength greater than or equal to 4 MPa.

Claims

1. A photocrosslinkable composition comprising: - Monofunctional (meth)acrylate monomers, -Functionalized core-shell filler - (meth)acrylate polymers, preferably (meth)acrylate oligomers, selected from urethane (meth)acrylate polymers, polyester (meth)acrylate polymers, epoxy (meth)acrylate polymers, and mixtures thereof, and -Photoinitiator, The monofunctional (meth)acrylate monomers include cyclic alkyl acrylates and acyclic alkyl acrylates.

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

3. The photocrosslinkable composition according to claim 1 or 2, wherein the functionalized core-shell filler comprises a core containing a core polymer, a shell containing 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 comprises a functional group selected from epoxy groups, carboxylic acid groups, carboxamide groups, alkoxy groups, amine groups, cycloalkyl ester groups, and mixtures thereof, preferably selected from carboxamide groups, cycloalkyl ester groups, and mixtures thereof, and more preferably selected from cycloalkyl ester groups.

4. The photocrosslinkable composition according to claim 3, wherein the functional groups are derived from functional (meth)acrylates, more preferably from functional acrylates.

5. The photocrosslinkable composition according to any one of claims 1 to 4, wherein the (meth)acrylate polymer is selected from urethane (meth)acrylate polymers.

6. The photocrosslinkable composition according to any one of claims 1 to 5, wherein the (meth)acrylate polymer has a glass transition temperature of less than 30°C, preferably less than 0°C.

7. The photocrosslinkable composition according to any one of claims 1 to 6, further comprising an adhesion promoter.

8. The photocrosslinkable composition according to any one of claims 1 to 7, comprising: - Monofunctional (meth)acrylate monomers between 20 wt% and 80 wt%, - Functionalized core-shell fillers between 1% and 30% by weight - A (meth)acrylate polymer selected from urethane (meth)acrylate polymers, polyester (meth)acrylate polymers, epoxy (meth)acrylate polymers, and mixtures thereof, between 5% and 50% by weight. - Photoinitiators between 0.1 wt% and 5 wt%, - Adhesion promoters between 5% and 25% by weight -Optional up to 30% by weight of acrylic block copolymers -Optionally up to 30% by weight of one or more additives selected from crosslinking agents, fillers, heat stabilizers, UV stabilizers, ultraviolet or infrared fluorescent agents, dispersants, plasticizers, rheology modifiers, solvents, hygroscopic agents, and mixtures thereof. Weight percentage is relative to the total weight of the composition.

9. 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.

10. A method for assembling a substrate, comprising: - The photocrosslinkable composition according to any one of claims 1 to 8 is coated onto at least one surface of the substrate to be assembled, and then -Make the substrate come into contact, and then - To crosslink the composition.

11. An article comprising a photocrosslinkable composition according to any one of claims 1 to 8, said composition bonding at least two substrates of said article.

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