Dual cure compositions based on acrylate functional compounds

Abstract

The present invention relates to a dual-cure composition that can be cured at room temperature but is also heat-curable or photocurable. The composition comprises, based on the weight of the composition, 10-95% by weight of a) at least one epoxy acrylate compound having at least two acrylate groups; and 5-90% by weight of b) at least one polythiol compound, the composition being characterized in that the molar ratio of thiol groups (-SH) to acrylate groups (H2C=CHC(O)O-) ranges from 0.2:1 to 1:1, preferably 0.5:1 to 1:1. The composition may be further characterized in that it is free of a free radical initiator.

Description

[Technical field]

[0001] The present invention relates to a dual cure composition. More specifically, the present invention relates to a composition that can be cured at room temperature or using actinic radiation and / or heat, comprising an epoxy acrylate monomer and a thiol functional compound. [Background technology]

[0002] Compositions that are curable by actinic radiation, such as coating compositions, can traditionally be cured in a relatively short time by exposure to a radiation source. Rapid curing of the composition allows manufacturers to increase throughput, for example, in industrial coating processes. However, many coated substrates have areas that are difficult to expose to actinic radiation: for example, the surfaces of circuit boards and electronic components are often very rough, so that it can be difficult to fully expose a conformal coating applied to the surface. This difficulty in exposing the applied composition to actinic radiation leads to the problem that some of the applied composition in the "shadow" areas remains uncured.

[0003] The present invention seeks to address the problem of achieving complete cure of photocurable compositions based on acrylate-functional compounds in all areas not irradiated by the initial incident light source. This problem has traditionally been addressed in the art by providing compositions that are curable upon exposure to heat in addition to being curable upon exposure to actinic radiation. Such compositions are referred to as dual-cure.

[0004] US 2007029034 A1 (Mgaya et al.) discloses a dual-cure adhesive composition comprising: a) an aqueous emulsion of at least one vinyl ester homopolymer or copolymer; b) at least one (meth)acrylate-functionalized monomer and / or oligomer capable of polymerization and / or crosslinking upon exposure to ultraviolet or visible light; and c) at least one photoinitiator.

[0005] U.S. Patent No. 10,174,146 B2 (Morin et al.) discloses a dual cure composition that is applied using the method of: a) mixing at least one polymerizable acrylic compound, a thermal initiator, a photoinitiator, and a peroxide to form a mixture, where the peroxide has a decomposition temperature; b) exposing the mixture to light for a first time sufficient to form a first curing agent; and c) after exposing the mixture to light, exposing the mixture to a temperature below the decomposition temperature of the peroxide for a second time sufficient to form a second curing agent.

[0006] WO 2013 / 023545 (Henkel China Company Ltd.) discloses a dual-cure adhesive composition comprising, based on the total weight of the adhesive composition, 10-90 wt. % of a photocurable oligomer or polymer having pendant (meth)acryloyloxy or vinyl groups; 5-55 wt. % of a (meth)acrylate; 0-50 wt. % of a liquid polybutadiene; 0.5-5 wt. % of a UV photoinitiator; and 0.5-5 wt. % of a thermal initiator.

[0007] KR 102155180 B1 (KCC Corporation) discloses a dual-cure adhesive composition that is photocurable and thermally curable and includes an epoxy (meth)acrylate oligomer; a polyol (meth)acrylate oligomer; a (meth)acrylate monomer; a photoinitiator; and a thermal initiator. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] US 2007029034 A1 [Patent Document 2] US Patent Number 10174146B2 [Patent Document 3] WO 2013 / 023545 [Patent Document 4] KR 102155180 B1 Summary of the Invention [Problem to be solved by the invention]

[0009] The presence of photoinitiators in these prior art compositions should be noted. Those skilled in the art will also recognize that in examples of such prior art compositions, the compositions generally contain photosensitizers to improve the efficiency with which the photoinitiator uses the supplied energy by increasing the rate of photoinitiated polymerization or shifting the wavelength at which polymerization occurs. Photoinitiators and sometimes photosensitizers can generate photochemically residual compounds in the final cured product. These residues can be detected by conventional analytical techniques such as infrared, ultraviolet and NMR spectroscopy; gas or liquid chromatography; and mass spectrometry. Thus, prior art compositions can contain a cured matrix (co)polymer and at least a detectable amount of residue from the photoinitiator. [Means for solving the problem]

[0010] According to a first embodiment of the present invention, based on the weight of the dual cure composition, 10 to 95% by weight of a) at least one epoxy acrylate compound having at least two acrylate groups; and 5 to 90% by weight of b) at least one polythiol compound A dual cure composition comprising: The composition is characterized in that the molar ratio of thiol groups (-SH) to acrylate groups (HC=CHC(O)O-) is in the range of 0.2:1 to 1:1; The composition is curable at room temperature, but can also be cured by heating or by irradiation with light. A dual cure composition is provided.

[0011] In one embodiment, the dual cure composition comprises, based on the weight of the composition: 20-90% by weight, preferably 40-90% by weight, of a) said at least one epoxy acrylate compound having at least two acrylate groups; 10 to 80% by weight, preferably 10 to 60% by weight, of b) said at least one polythiol compound; and 0 to 50% by weight, preferably 0 to 30% by weight of c) at least one ethylenically unsaturated nonionic monomer comprising The composition is characterized in that the molar ratio of thiol groups (-SH) to acrylate groups (H2C=CHC(O)O-) is in the range of 0.2:1 to 1:1, preferably in the range of 0.5:1 to 1:1.

[0012] The dual curing composition should be substantially free of free radical photoinitiators and / or free radical thermal initiators. Indeed, compositions useful in the present invention that are free of both free radical thermal initiators and free radical photoinitiators have been shown to effectively cure at room temperature or independently under heat and light irradiation. For completeness, in an important embodiment, the compositions of the present invention may be substantially free of free radical initiators.

[0013] The or each epoxy acrylate compound present in the composition is preferably an adduct of acrylic acid and a polyepoxide compound.In an exemplary embodiment, the polyepoxide is selected from the group consisting of polyglycidyl ethers of polyhydric alcohols; polyglycidyl ethers of polyhydric phenols; polyglycidyl esters of polycarboxylic acids; and epoxidized polyethylenically unsaturated hydrocarbons.More specifically, the polyepoxide is a diglycidyl ether selected from the group consisting of diglycidyl ethers of aliphatic and cycloaliphatic diols; bisphenol A-based diglycidyl ethers; bisphenol F diglycidyl ethers; polyalkylene glycol-based diglycidyl ethers; and polycarbonate diol-based glycidyl ethers.

[0014] The or each polythiol compound contained in the composition should preferably have from 2 to 5 thiol groups. Independently of or in addition to this functionality, the or each polythiol compound contained in the composition should have a weight average molecular weight (Mw) of less than 20,000 Daltons, preferably from 200 to 800 Daltons.

[0015] Exemplary polythiol compounds are polyesters of thiocarboxylic acids, and particular mention may be made of the following compounds, either alone or in combination: pentaerythritol tetramercaptoacetate; pentaerythritol tetrakis(3-mercaptopropionate); trimethylolpropane trimercaptoacetate (TMPMP); tris(2-(mercaptopropionyloxy)ethyl)isocyanate; and glycol dimercaptoacetate.

[0016] The molar ratio terms characterizing the composition indicate that there should not be a molar excess of thiol groups (-SH) relative to acrylate groups (H2C=CHC(O)O-). For completeness, the molar ratio terms relate to the total number of acrylate and thiol groups present in the composition. Thus, when element c) is present and comprises a monomer having an acrylate functionality, the molar ratio term of thiol groups to acrylate groups includes contributions from both element a) and element c) of the composition.

[0017] In a second embodiment of the present invention, there is provided the use of a dual cure composition as described above and defined in the claims as a coating, adhesive or sealant. The use of the dual cure composition in composites is also envisaged. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] As used herein, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0019] As used herein, the terms "comprise," "including," and "comprising" are synonymous with "including," "comprises," "comprising," or "containing," and are inclusive or open-ended and do not exclude additional, unrecited members, elements, or method steps.

[0020] As used herein, the term "consisting of" excludes any element, component, material, or method step not listed.

[0021] When amounts, concentrations, dimensions, and other parameters are expressed as ranges, preferred ranges, upper values, lower values, or preferred upper and preferred lower values, it is to be understood that the range obtained by combining any upper or preferred upper value with any lower or preferred lower limit is also specifically disclosed, regardless of whether the resulting range is expressly stated in the context.

[0022] Also, in accordance with standard understanding, a weight range expressed as "from 0 to x" specifically includes 0% by weight. The component defined by said range may be absent from the composition or may be present in the composition in an amount up to x by weight.

[0023] The terms "preferred," "preferred," "desirable," and "particularly" are used frequently herein to refer to embodiments of the present disclosure that may afford certain benefits, under particular circumstances. However, the recitation of one or more preferred, preferred, desirable or particular embodiments does not imply that other embodiments are not useful, and is not intended to exclude such other embodiments from the scope of the invention.

[0024] The word "may" as used throughout this application is used in its permissive or potential sense rather than its mandatory sense.

[0025] As used herein, room temperature is 23°C ± 2°C.

[0026] Molecular weights referred to herein are intended to describe the macromolecular, oligomeric and polymeric components of the curable compositions and can be determined by gel permeation chromatography (GPC) using polystyrene calibration standards, such as those performed in accordance with ASTM 3536.

[0027] The viscosity of the compositions described herein is measured using a Brookfield viscometer at standard conditions of 20° C. and 50% relative humidity (RH), unless otherwise specified. The calibration method, spindle type and rotation speed of the Brookfield viscometer are selected according to the manufacturer's instructions as appropriate for the composition to be measured.

[0028] As used herein, the term "monomer" refers to a substance that can undergo a polymerization reaction to provide a building block for the chemical structure of a polymer. As used herein, the term "monofunctional" refers to having one polymerizable moiety. As used herein, the term "multifunctional" refers to having two or more polymerizable moieties.

[0029] The term "equivalents (eq.)" as used herein, as is usual in chemical notation, relates to the relative numbers of reactive groups present in a reaction.

[0030] As used herein, the term "equivalent weight" refers to the molecular weight divided by the number of functional groups involved. For example, "epoxy equivalent weight (EEW)" means the weight of a resin in grams that contains one equivalent of epoxy.

[0031] As used herein, the term "epoxide" refers to a compound characterized by the presence of at least one cyclic ether group, i.e., an ether oxygen atom is bonded to two adjacent carbon atoms, thereby forming a cyclic structure. The term is intended to encompass monoepoxide compounds, polyepoxide compounds (having two or more epoxide groups), and epoxide-terminated prepolymers. The term "monoepoxide compound" refers to an epoxide compound having one epoxy group. The term "polyepoxide compound" refers to an epoxide compound having at least two epoxy groups. The term "diepoxide compound" refers to an epoxide compound having two epoxy groups.

[0032] The epoxides may be unsubstituted or inertly substituted. Exemplary inert substituents include chlorine, bromine, fluorine and phenyl.

[0033] As used herein, the term "polythiol" refers to a simple or complex organic compound having at least two pendant or terminal thiol groups (-SH) per molecule. Such polythiols generally have the formula: t -(SH) c where c is an integer having a value of at least 2, and R t is a polyvalent organic group having a valence of c.

[0034] The term "free radical initiator" as used herein refers to a chemical species that, when exposed to sufficient energy (e.g., in the form of light or heat), is uncharged but breaks down into two parts, each having at least one unpaired electron. For example, a free radical thermal initiator produces a free when exposed to heat. Known free radical thermal initiators include, but are not limited to, peroxides, azo compounds, and persulfate compounds.

[0035] The term "photoinitiator" as used herein refers to a compound that can be activated upon exposure to energy-carrying activating light (such as electromagnetic radiation). In particular, the term "free radical photoinitiator" as used herein refers to a photoactive compound that generates free radicals. The radicals can initiate polymerization or reactions by adding to C=C double bonds present in the composition. Such free radical photoinitiators are typically classified as Norrish Type I and Norrish Type II photoinitiators. Norrish Type I radical photoinitiators undergo a Norrish Type I reaction upon exposure to actinic radiation: this reaction is defined by IUPAC as the α-cleavage of an excited carbonyl compound resulting in an acyl-alkyl radical pair (from acyclic carbonyl compounds) or an acyl-alkyl biradical (from cyclic carbonyl compounds) as the primary photoproduct. Norrish Type II radical photoinitiators undergo a Norrish Type II reaction upon exposure to actinic radiation: this reaction is defined by IUPAC as the photochemical abstraction of γ-hydrogen by an excited carbonyl compound producing a 1,4-biradical as the primary photoproduct.

[0036] As used herein, "C1-C n An "alkyl" group refers to a monovalent group containing 1 to n carbon atoms, which is a radical of an alkane and includes straight-chain and branched organic groups. For example, "C1 to C 18 An "alkyl" group refers to a monovalent group containing 1 to 18 carbon atoms, which is a group of alkanes and includes straight-chain and branched organic groups. Examples of alkyl groups include, but are not limited to, methyl; ethyl; propyl; isopropyl; n-butyl; isobutyl; sec-butyl; tert-butyl; n-pentyl; n-hexyl; n-heptyl; and 2-ethylhexyl. In the present invention, such alkyl groups may be unsubstituted or substituted with one or more halogens. If applicable to a particular moiety (R), the permissible range of one or more non-halogen substituents in an alkyl group is described in the specification.

[0037] As used herein, "C1-C 18 The term "hydroxyalkyl" refers to a HO-(alkyl) group having 1 to 18 carbon atoms, where the point of attachment of the substituent is through the oxygen atom and the alkyl group is as defined above.

[0038] "Alkoxy group" refers to a monovalent group represented by -OA, where A is an alkyl group. Non-limiting examples thereof are methoxy, ethoxy, and isopropyloxy groups. As used herein, "C1-C 18 The term "alkoxyalkyl" refers to an alkyl group having an alkoxy substituent, as defined above, where the moiety (alkyl-O-alkyl) contains a total of 1 to 18 carbon atoms. Such groups include methoxymethyl (-CHOCH), 2-methoxyethyl (-CHCHOCH), and 2-ethoxyethyl.

[0039] The term "C2-C4 alkylene," as used herein, is defined as a saturated divalent hydrocarbon group having two to four carbon atoms.

[0040] "C3~C 18 The term "cycloalkyl" is understood to mean a saturated monocyclic or polycyclic hydrocarbon group having 3 to 18 carbon atoms. In the present invention, such cycloalkyl groups may be unsubstituted or substituted with one or more halogens. If applicable to a particular moiety (R), the tolerance for one or more non-halogen substituents in the cycloalkyl group is described herein. Examples of cycloalkyl groups include cyclopropyl; cyclobutyl; cyclopentyl; cyclohexyl; cycloheptyl; cyclooctyl; adamantane and norbornane.

[0041] As used herein, the term "C6-C alkyl group" used alone or as part of a larger moiety (as in the case of an "aralkyl group") refers to a C6-C alkyl group. 18"Aryl" groups refer to monocyclic, bicyclic and tricyclic ring systems, where the monocyclic ring system is aromatic or at least one of the rings of the bicyclic or tricyclic ring system is aromatic. Bicyclic and tricyclic ring systems include benzo-fused 2-3 membered carbocyclic rings. In the present invention, such aryl groups may be unsubstituted or substituted with one or more halogens. If applicable to a particular moiety (R), the allowance for one or more non-halogen substituents in the aryl group is described herein. Examples of aryl groups include phenyl; (C1-C4) alkylphenyl, such as tolyl and ethylphenyl; indenyl; naphthalenyl, tetrahydronaphthyl, tetrahydroindenyl; tetrahydroanthracenyl; and anthracenyl. It may be mentioned that the phenyl group is preferred.

[0042] As used herein, "alkylaryl" refers to an alkyl-substituted aryl group, both of which are as defined above. Also, as used herein, "aralkyl" refers to an alkyl group substituted with an aryl group, as defined above.

[0043] The compositions of the present invention may be defined herein as being "substantially free" of a particular compound, element, ion, or other similar component. The term "substantially free" is intended to mean that the compound, element, ion, or other similar component is not intentionally added to the composition and is present at most in trace amounts that do not (negatively) affect the desired properties of the coating. A typical trace amount is less than 1000 ppm by weight of the composition. The term "substantially free" explicitly encompasses embodiments in which the particular compound, element, ion, or other similar component is completely absent from the composition or is absent in amounts measurable by techniques commonly used in the art.

[0044] a) Epoxy acrylate compounds The composition comprises at least one epoxy acrylate compound having at least two acrylate groups in an amount of 10-95% by weight based on the weight of the composition, preferably comprising 20-90% by weight, such as 40-90% by weight, of the composition.

[0045] The epoxy acrylate compound is obtained as a reaction product of acrylic acid and a polyepoxide compound. Although it is not intended to limit the present invention, the polyepoxide compound suitable as a reactant may be liquid, solid or in solution in a solvent. Such polyepoxide compound should have an epoxide equivalent weight of 100 to 700 g / eq, for example 120 to 320 g / eq. Also, diepoxide compounds having an epoxide equivalent weight of less than 500 g / eq or less than 400 g / eq are generally preferred. This is mainly from the viewpoint of cost, since low molecular weight epoxy resins require more limited purification treatment during their production.

[0046] Examples of types or groups of polyepoxide compounds which can be reacted with acrylic acid include: polyglycidyl ethers of polyhydric alcohols and polyhydric phenols; polyglycidyl esters of polycarboxylic acids; and epoxidized polyethylenically unsaturated hydrocarbons.

[0047] The use of diepoxide compounds is preferred. For example, suitable diglycidyl ether compounds may be aromatic, aliphatic or cycloaliphatic in nature and thus derived from dihydric phenols and dihydric alcohols. Useful groups of such diglycidyl ethers are: diglycidyl ethers of aliphatic and cycloaliphatic diols, such as 1,2-ethanediol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,12-dodecanediol, cyclopentanediol and cyclohexanediol; bisphenol A-based diglycidyl ethers; bisphenol F diglycidyl ethers; diglycidyl o-phthalate, diglycidyl isophthalate and diglycidyl terephthalate; polyalkylene glycol-based diglycidyl ethers, in particular polypropylene glycol diglycidyl ethers; and polycarbonate diol-based glycidyl ethers. Other suitable diepoxides which may also be mentioned include: doubly unsaturated fatty acid C1-C 18 Diepoxides of alkyl esters; butadiene diepoxide; polybutadiene diglycidyl ether; vinylcyclohexane diepoxide; and limonene diepoxide.

[0048] Further exemplary polyepoxide compounds include, but are not limited to, glycerol polyglycidyl ether; trimethylolpropane polyglycidyl ether; pentaerythritol polyglycidyl ether; diglycerol polyglycidyl ether; polyglycerol polyglycidyl ether; and sorbitol polyglycidyl ether.

[0049] Examples of polyepoxide compounds which are particularly preferred reactants include: bisphenol A epoxy resins; bisphenol F epoxy resins; bisphenol A / F epoxy resin mixtures; polypropylene glycol diglycidyl ethers, such as DER. TM 732; Epoxy novolac resins, e.g. DEN TM 438; Brominated epoxy resins, e.g. DER TM542; Castor oil triglycidyl ethers, e.g. ERISYS TM GE-35H; Polyglycerol-3-polyglycidyl ether, e.g. ERISYS TM GE-38; and sorbitol glycidyl ethers, such as ERISYS TM GE-60.

[0050] Of course, epoxy acrylate compounds having at least two acrylate groups can be obtained from commercial sources. Representative commercially available epoxy diacrylates include, but are not limited to, bisphenol A epoxy diacrylate oligomers, Ebecryl 3700, Ebecryl 3702 and Ebecryl 3703 available from Daicel-Cytec Company Ltd; ethoxylated bisphenol A epoxy diacrylate compounds, SR601, SR602 and CD9038 available from Sartomer; and Photomer 3016 available from IGM Resins.

[0051] It should be noted that the polyepoxide compounds useful for producing epoxy acrylate adducts can be monomeric or oligomeric. It is believed that the inclusion of monomeric epoxy acrylates in the compositions of the present invention will generally result in a cured product with hard, wear-resistant properties. Conversely, the inclusion of oligomeric multifunctional acrylates will generally result in a somewhat softer, more flexible cured product. Of course, the use of both monomeric and oligomeric epoxy acrylate compounds can also balance the desired properties of the cured product.

[0052] b) Polythiol Compound The composition of the present invention comprises at least one polythiol compound b), in which the molar ratio of thiol groups (-SH) to acrylate groups (H2C=CHC(O)O-) is in the range of 0.2:1 to 1:1, preferably in the range of 0.5:1 to 1:1.

[0053] In terms of this molar ratio, the composition comprises 5 to 90% by weight, preferably 10 to 80% by weight, of said at least one polythiol compound b), based on the weight of the composition. For example, the composition may comprise 10 to 60% by weight, preferably 15 to 40% by weight, of said at least one polythiol compound b), based on the weight of the composition.

[0054] In a preferred embodiment, the or each polythiol compound contained in the composition should have from 2 to 5 thiol groups, for example from 2 to 4 thiol groups. Independently or in addition to this functionality requirement, it is preferred that the or each polythiol compound contained in the composition has a weight average molecular weight (Mw) of less than 20,000 Daltons, for example less than 5000 Daltons, preferably from 200 to 800 Daltons.

[0055] Suitable thiol-containing compounds that may be used alone or in combination include, but are not limited to, the following: Liquid thiol (SH)-terminated polysulfide polymers, commercially available examples of which include Thiokol® polymers (available from Morton Thiokol), in particular types LP-3, LP-33, LP-980, LP-23, LP-55, LP-56, LP-12, LP-31, LP-32 and LP-2; and Thioplast® polymers (from Akzo Nobel), in particular types G10, G112, G131, G1, G12, G21, G22, G44 and G4. Thiol (SH)-terminated polyoxyalkylene ethers obtained by reaction of polyoxyalkylene di- and triols with epichlorohydrin or alkylene oxides and subsequent reaction with sodium hydrogen sulfide. Thiol (SH) terminated compounds as polyoxyalkylene derivatives known under the trade name Capcure® (manufactured by Cognis), in particular types WR-8, LOF and 3-800. Polyesters of thiocarboxylic acids such as mercaptoacetic acid (thioglycolic acid), mercaptopropionic acid, mercaptobenzoic acid and mercaptosuccinic acid. Specific examples of such polyesters include pentaerythritol tetramercaptoacetate, pentaerythritol tetrakis(3-mercaptopropionate), trimethylolpropane trimercaptoacetate (TMPMP), glycol dimercaptoacetate, and the esterification products of polyoxyalkylene diols and triols, ethoxylated trimethylolpropane and polyester diols with thiocarboxylic acids (e.g. mercaptoacetic acid (thioglycolic acid) and 2- or 3-mercaptopropionic acid). 2,4,6-Trimercapto-1,3,5-triazine, 2,2'-(ethylenedioxy)-diethanethiol (triethylene glycol dimercaptan) and / or ethanedithiol. ·Tris(2-(mercaptopropionyloxy)ethyl)isocyanate.

[0056] It is found that it is preferable to use polyesters of thiocarboxylic acids, and in particular at least one of pentaerythritol tetramercaptoacetate; pentaerythritol tetrakis(3-mercaptopropionate); trimethylolpropane trimercaptoacetate (TMPMP); tris(2-(mercaptopropionyloxy)ethyl)isocyanate; and glycol dimercaptoacetate.

[0057] c) Ethylenically unsaturated nonionic monomers The composition of the present disclosure comprises 0-50 wt% of at least one ethylenically unsaturated nonionic monomer based on the weight of the composition. It is preferred that the composition comprises 0-30 wt%, for example 0-20 wt%, of said at least one ethylenically unsaturated nonionic monomer.

[0058] The monomer of this component c) in the composition is different from the epoxy acrylate monomer of component a). Apart from that, such a monomer may in principle be any other ethylenically unsaturated nonionic monomer. However, the invention is particularly applicable to compositions in which the acrylate monomer constitutes at least 60% by weight, preferably at least 75% by weight or at least 85% by weight of the total amount of ethylenically unsaturated nonionic monomers present in the composition.

[0059] With regard to the room temperature curing ability of the compositions of the present invention, it is preferred that component c) is substantially free of ethylenically unsaturated nonionic monomers having methacrylate functionality.

[0060] C.1 Acrylate Monomers There is no particular intent to limit the acrylic acid esters useful in the present invention, and it is believed that the acrylate monomer can be any ester of acrylic acid known in the art. Thus, exemplary acrylate monomers include, but are not limited to, the following: C1-C acrylates, such as methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, butyl acrylate (all isomers), hexyl acrylate, n-heptyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, n-nonyl acrylate, n-decyl acrylate, n-dodecyl acrylate, and n-stearyl acrylate. 18 Alkyl esters; -C3-C acrylic acids such as cyclohexyl acrylate and isobornyl acrylate 18 Cycloalkyl esters; C6-C acrylic acids such as phenyl acrylate and tolyl acrylate 18 Aryl esters; C7 to C of acrylic acid, such as benzyl acrylate 24 Aralkyl esters; C1-C of acrylic acid, such as 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, and 3-methoxybutyl acrylate 18Alkoxyalkyl esters; Fluorine-containing C1-C acrylates of acrylic acid, such as trifluoromethyl methyl acrylate, 2-trifluoromethylethyl acrylate, 2-perfluoroethyl ethyl acrylate, 2-perfluoroethyl-2-perfluorobutyl ethyl acrylate, 2-perfluoroethyl acrylate, perfluoromethyl acrylate, diperfluoromethyl methyl acrylate, 2-perfluoromethyl-2-perfluoroethyl methyl acrylate, 2-perfluorohexyl ethyl acrylate, 2-perfluorodecyl ethyl acrylate, and 2-perfluorohexadecyl ethyl acrylate. 18 Alkyl esters; C1-C of acrylic acid, such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and pentaerythritol triacrylate 18 Hydroxyalkyl esters, especially C1-C6 hydroxyalkyl esters of acrylic acid; · Di / polyesters of di- or polyfunctional alcohols such as ethylene glycol diacrylate, 1,3- or 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate and trimethylolpropane triacrylate; C1-C of acrylic acid, such as 2-aminoethyl acrylate, dimethylaminoethyl acrylate, and acryloxyethoxyethylamine 18 Aminoalkyl esters; C1-C of acrylic acid, such as (3-acryloyloxypropyl)trimethoxysilane 18 Alkoxysilyl-containing alkyl esters; Ethylene oxide or propylene oxide adducts of acrylic acid; and Acrylic esters produced with alcohols containing other functional groups, such as tetrahydrofurfuryl acrylate.

[0061] For the sake of completeness, it is not excluded that element c) of the composition comprises a macromonomer component consisting of one or more oligomers selected from the group consisting of urethane acrylates, polyester acrylates and polyether acrylates, however such oligomeric compounds (which may be mono- or polyfunctional with respect to the polymerizable acrylate functional groups, but based on repeating urethane, ester and ether subunits) should usually not constitute more than 30% by weight of the total of the acrylate monomers in said composition.

[0062] As known in the art, urethane acrylate oligomers can be prepared by reacting the polyisocyanate defined herein above with a hydroxyl group-containing multifunctional acrylate.Specifically, the hydroxyl group-containing multifunctional acrylate can be selected from the group consisting of 2-hydroxyethyl acrylate, 2-hydroxyisopropyl acrylate, 4-hydroxybutyl acrylate, hydroxyethyl caprolactone acrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, and combinations thereof.

[0063] Suitable polyester acrylate oligomers are obtained by reacting acrylic acid with polyesters prepared from polybasic acids or their anhydrides and polyhydric alcohols. Examples of polybasic acids include, but are not limited to, phthalic acid, succinic acid, adipic acid, glutaric acid, sebacic acid, isosebacic acid, tetrahydrophthalic acid, hexahydrophthalic acid, dimer acid, trimellitic acid, pyromellitic acid, pimelic acid, and azelaic acid. Examples of polyhydric alcohols include, but are not limited to, 1,6-hexanediol, diethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, neopentyl glycol, dipropylene glycol, polyethylene glycol, and polypropylene glycol.

[0064] As is known in the art, polyether acrylate oligomers may be obtained by transesterification of polyethers with acrylic esters such as ethyl acrylate. Exemplary polyethers include those obtained from ethoxylated or propoxylated trimethylolpropane, pentaerythritol, etc., or by polyetherification of 1,4-propanediol, etc.

[0065] In a preferred embodiment, the composition comprises at least one acrylate monomer selected from the group consisting of: methyl acrylate; ethyl acrylate; n-propyl acrylate; isopropyl acrylate; n-butyl acrylate; isobutyl acrylate; tert-butyl acrylate; n-pentyl acrylate; n-hexyl acrylate; cyclohexyl acrylate; n-heptyl acrylate; n-octyl acrylate; 2-ethylhexyl acrylate; nonyl acrylate; decyl acrylate; dodecyl acrylate; phenyl acrylate; Tolyl acrylate;Benzyl acrylate;2-Methoxyethyl acrylate;3-Methoxybutyl acrylate;2-Hydroxyethyl acrylate;2-Hydroxypropyl acrylate;Stearyl acrylate;Glycidyl acrylate;Isobornyl acrylate;2-Aminoethyl acrylate;y-Acryloyloxypropyltrimethoxysilane;Acrylic acid-ethylene oxide adduct;Trifluoromethyl methyl acrylate;2-Trifluoromethylethyl acrylate;2-Perfluoroethylethyl acrylate;2-Perf Perfluoroethyl-2-perfluorobutylethyl acrylate;2-Perfluoroethyl acrylate;Perfluoromethyl acrylate;Diperfluoromethyl methyl acrylate;2-Perfluoromethyl-2-perfluoroethyl methyl acrylate;2-Perfluorohexylethyl acrylate;2-Perfluorodecylethyl acrylate;2-Perfluorohexadecylethyl acrylate;Ethoxylated trimethylolpropane triacrylate;Trimethylolpropane triacrylate;Dipentaerythritol monohydroxypenta Acrylates;Pentaerythritol triacrylate;1,6-Hexanediol diacrylate;Neopentyl glycol diacrylate;Pentaerythritol tetraacrylate;1,2-Butylene glycol diacrylate;Trimethylolpropane ethoxylate triacrylate;Glyceryl propoxylate triacrylate;Trimethylolpropane triacrylate;Dipentaerythritol monohydroxypentacrylate;Tripropylene glycol diacrylate;Neopentyl glycol propoxylate diacrylate;1,4-butanediol diacrylate; triethylene glycol diacrylate; and butylene glycol diacrylate.

[0066] C.2 Copolymerizable acids The composition may optionally include at least one copolymerizable acid. When used, the acid may be added in an amount of up to 40% by weight, such as up to 25% by weight, of the total amount of ethylenically unsaturated nonionic monomers present. Thus, the at least one copolymerizable acid may constitute 0-15% by weight of the total amount of ethylenically unsaturated nonionic monomers. For completeness, such monomers should typically be used in the form of their free acid, but nothing prevents the constituent acid groups of the monomers from being partially or completely neutralized with a suitable base, so long as their participation in the copolymerization is not impaired.

[0067] Without intending to limit the invention, the copolymerizable acid monomer should be selected from the following: ethylenically unsaturated carboxylic acids; ethylenically unsaturated sulfonic acids; and vinylphosphonic acids. Suitable ethylenically unsaturated sulfonic acids are, for example, vinyl sulfonic acid, styrene sulfonic acid, and acrylamidomethylpropane sulfonic acid.

[0068] The at least one copolymerizable acid in the composition preferably comprises or consists of an ethylenically unsaturated carboxylic acid selected from the group consisting of α,β-monoethylenically unsaturated monocarboxylic acids; α,β-monoethylenically unsaturated dicarboxylic acids; C1-C6 alkyl half esters of α,β-monoethylenically unsaturated dicarboxylic acids; α,β-monoethylenically unsaturated tricarboxylic acids; and C1-C6 alkyl esters of α,β-monoethylenically unsaturated tricarboxylic acids having at least one free carboxylic acid group; and mixtures thereof. Specifically, the at least one copolymerizable acid in the composition preferably comprises or consists of an ethylenically unsaturated carboxylic acid selected from the group consisting of methacrylic acid; acrylic acid, itaconic acid; maleic acid; aconitic acid; crotonic acid; fumaric acid; and mixtures thereof.

[0069] C.3 Further monomers It should be noted that the present invention does not exclude the presence in the composition of vinyl monomers that can be copolymerized with the acrylate monomers and are selected from the group consisting of: styrene monomers, such as styrene, vinyltoluene, α-methylstyrene and chlorostyrene; fluorine-containing vinyl monomers, such as perfluoroethylene, perfluoropropylene and vinylidene fluoride; silicon-containing vinyl monomers, such as vinyltrimethoxysilane and vinyltriethoxysilane; maleimide monomers, such as maleimide, methylmaleimide, ethylmaleimide, propylmaleimide, butylmaleimide. , hexylmaleimide, octylmaleimide, dodecylmaleimide, stearylmaleimide, phenylmaleimide and cyclohexylmaleimide; nitrile group-containing vinyl monomers such as acrylonitrile and methacrylonitrile; amide group-containing vinyl monomers such as acrylamide and methacrylamide; vinyl esters such as vinyl acetate, vinyl propionate, vinyl pivalate, vinyl benzoate and vinyl cinnamate; alkenes such as ethylene and propylene; conjugated dienes such as butadiene and isoprene; and vinyl chloride, vinylidene chloride, allyl chloride and allyl alcohol.

[0070] Additives and auxiliary ingredients The compositions obtained according to the present invention may typically further comprise auxiliaries and additives that can provide these compositions with improved properties. For example, the auxiliaries and additives may provide one or more of the following: improved elastic properties, improved elastic recovery, longer processing time, faster curing time, and lower residual tack. Such auxiliaries and additives include catalysts; plasticizers; stabilizers, including UV stabilizers; antioxidants; reactive diluents; non-reactive diluents; drying agents; adhesion promoters; fungicides; flame retardants; rheological aids; fillers; and color pigments or color pastes.

[0071] Such auxiliaries and additives may be used in any desired combination and proportion, provided they do not adversely affect the properties and essential characteristics of the composition. Although exceptions may exist, these auxiliaries and additives, taken as a whole, should not exceed 50% by weight of the entire composition, and preferably should not exceed 20% by weight of the composition.

[0072] The composition of the present invention may optionally include a Michael addition catalyst. In this specification, the Michael addition catalyst refers to a compound that can promote the Michael addition reaction between a polythiol compound and an acrylate group-containing compound. Conventionally, the Michael addition catalyst includes amine catalysts, base catalysts and organometallic catalysts, and these types can be used alone or in combination. Exemplary amine catalysts include proline; triazabicyclodecene (TBD); diazabicycloundecene (DBU); hexahydromethylpyrimidopyridine (MTBD); diazabicyclononane (DBN); tetramethylguanidine (TMG); and triethylenediamine (TEDA). Examples of base catalysts include sodium methoxide; sodium ethoxide; potassium t-butoxide; potassium hydroxide; sodium hydroxide; metallic sodium; lithium diisopropylamide (LDA); and butyl lithium. Exemplary organometallic catalysts include ruthenium catalysts such as (cyclooctadiene)(cyclooctatriene)ruthenium and ruthenium hydride; iron catalysts such as iron(III) chloride and iron acetylacetonate; nickel catalysts such as nickel acetylacetonate, nickel acetate, and nickel salicylaldehyde; copper catalysts; palladium catalysts; scandium catalysts; lanthanum catalysts; ytterbium catalysts; and tin catalysts.

[0073] In the present invention, the Michael addition catalyst may be used in an amount of 0-5% by weight, for example 0-2% by weight, based on the weight of the composition. However, again, such a Michael addition catalyst need not be present in the composition. Indeed, in a preferred embodiment, the composition is substantially free of a Michael addition catalyst.

[0074] A "plasticizer" for the purposes of the present invention is a substance that reduces the viscosity of the composition and therefore enhances its processability. As used herein, the plasticizer may constitute 0-10% by weight or 0-5% by weight based on the total weight of the composition. When present, the plasticizer is preferably a diurethane; a monofunctional linear or branched C4-C 16 The plasticizers are selected from the group consisting of ethers of alcohols, such as Cetiol OE (available from Cognis Deutschland GmbH, Düsseldorf); esters of abietic acid, butyric acid, thiobutyric acid, acetic acid, propionic acid, and citric acid; esters based on nitrocellulose and polyvinyl acetate; fatty acid esters; dicarboxylic acid esters; esters of OH-containing fatty acids; glycolic acid esters; benzoic acid esters; phosphoric acid esters; sulfonic acid esters; trimellitic acid esters; polyether plasticizers, such as end-capped polyethylene or polypropylene glycols; polystyrene; hydrocarbon plasticizers; chlorinated paraffins; and mixtures thereof. In principle, phthalic acid esters can also be used as plasticizers, but it should be noted that they are not preferred due to possible toxicity.

[0075] "Stabilizer" for the purposes of the present invention should be understood as antioxidant, UV stabilizer, heat stabilizer or hydrolysis stabilizer. In the present invention, the stabilizers should constitute in total 0-10% by weight or 0-5% by weight based on the total weight of the composition. Standard commercial examples of stabilizers suitable for use in the present invention include: sterically hindered phenols; thioethers; benzotriazoles; benzophenones; benzoates; cyanoacrylates; acrylates; amines of the hindered amine light stabilizer (HALS) type; phosphorus; sulfur; and mixtures thereof.

[0076] The composition of the present disclosure may include a particulate filler. The desired viscosity of the resulting curable composition may depend on the amount of filler used. With the latter in mind, the total amount of filler should not prevent easy application of the composition by the selected method of applying the composition to the substrate. For example, compositions of the present invention intended to be applied to a specific site by printing or injection should have a viscosity of 1000 to 50,000, preferably 10,000 to 20,000 mPas.

[0077] Generally, there is no particular intention to limit the shape of the particles used as fillers. Acicular, spherical, ellipsoidal, cylindrical, beaded, cubic, or platelet-shaped particles may be used, either alone or in combination. It is also envisioned that aggregates of multiple particle types may be used. Similarly, there is no particular intention to limit the dimensions of the particles used as fillers. However, such fillers may have an average particle size (d50) of 0.1 to 1000 μm, e.g., 1 to 500 μm, as conventionally measured by laser diffraction / scattering methods.

[0078] Exemplary fillers include, but are not limited to, graphite, carbon black, calcium carbonate, calcium oxide, calcium chloride, calcium hydroxide (lime powder), calcium sulfate, fused silica, amorphous silica, precipitated and / or pyrogenic silicic acid, zeolites, bentonite, wollastonite, magnesium carbonate, magnesium sulfate, diatomaceous earth, barium sulfate, barium oxide, alumina, aluminum nitride, boron nitride, clay, talc, titanium dioxide, iron oxide, zinc oxide, sand, quartz, flint, mica, glass beads, glass powder, and other ground minerals. Organic fillers, such as wood fiber, wood flour, sawdust, cellulose, cotton, pulp, cotton, wood chips, shredded straw, rice husks, ground walnut shells, and other shredded fibers, can also be used, as can poly(tetrachloroethylene), poly(chlorotrifluoroethylene), and poly(vinylidene chloride) flours. Short fibers, such as glass fibers, glass filaments, polyacrylonitrile, carbon fibers, Kevlar fibers, or polyethylene fibers, can also be added.

[0079] Hollow spheres with mineral or plastic shells are also suitable as fillers. These can be, for example, hollow glass spheres, which are commercially available under the trade name Glass Bubbles®. Plastic-based hollow spheres, such as Expancel® or Dualite®, can also be used and are described in EP 0 520 426 B1. They are composed of inorganic or organic materials and each has a diameter of 1 mm or less, preferably 500 μm or less.

[0080] The use of core-shell rubber particles as a filler is not excluded. The term "core-shell rubber" or CSR is used according to the standard meaning in the art to describe a rubber particle core formed by a polymer containing an elastomeric or rubbery polymer as a main component, and a shell layer formed by a polymer grafted onto the core. The shell layer partially or entirely covers the surface of the rubber particle core in the graft polymerization process. By weight, the core should constitute at least 50% by weight of the core-shell rubber particle.

[0081] The core-shell rubber particles can be selected from commercially available products, examples of which include: Paraloid TMS-2670J, EXL 2650A, EXL 2655, and EXL2691 A available from The Dow Chemical Company; Clearstrength® XT100 available from Arkema Inc.; Kane Ace® MX series available from Kaneka Corporation, specifically MX 120, MX 125, MX 130, MX 136, MX 551, MX553; and METABLEN SX-006 available from Mitsubishi Rayon Co., Ltd.

[0082] Fillers that impart thixotropic properties to the composition may be preferred for many applications. Such fillers are also described as rheological aids, examples of which are hydrogenated castor oil, fatty acid amides, or swellable plastics such as PVC.

[0083] It should be noted that compounds having metal chelating properties may be used in the compositions of the present invention to enhance adhesion of the cured adhesive to the substrate surface. Also suitable for use as an adhesion promoter is an acetoacetate-functionalized modified resin sold by King Industries under the trade name K-FLEX XM-B301.

[0084] To further extend shelf life, it is often advisable to further stabilize the composition of the present invention with respect to moisture penetration using a desiccant. There is also often a need to reduce the viscosity of the adhesive or sealant composition of the present invention for certain applications by using a reactive diluent. The total amount of reactive diluent present can typically be 0-10% by weight, for example 0-5% by weight, based on the total weight of the composition.

[0085] The presence of solvents and non-reactive diluents in the composition of the present invention is not precluded, which may usefully moderate its viscosity.For example, and solely for illustrative purposes, the composition may include one or more of the following: xylene; 2-methoxyethanol; dimethoxyethanol; 2-ethoxyethanol; 2-propoxyethanol; 2-isopropoxyethanol; 2-butoxyethanol; 2-phenoxyethanol; 2-benzyloxyethanol; benzyl alcohol; ethylene glycol; ethylene glycol dimethyl ether; ethylene glycol diethyl ether; ethylene glycol dibutyl ether; ethylene glycol diphenyl ether; diethylene glycol; diethylene glycol monomethyl ether; diethylene glycol monoethyl ether; diethylene glycol mono-n-butyl ether; diethylene glycol dimethyl ether; diethylene glycol diethyl ether; diethylene glycol di-n-butyryl ether; propylene glycol; glycol butyl ether; propylene glycol phenyl ether; dipropylene glycol; dipropylene glycol monomethyl ether; dipropylene glycol dimethyl ether; dipropylene glycol di-n-butyl ether; N-methylpyrrolidone; diphenylmethane; diisopropyl naphthalene; petroleum distillates, such as the Solvesso® products (available from Exxon); alkylphenols, such as tert-butylphenol, nonylphenol, dodecylphenol, and 8,11,14-pentadecatrienylphenol; styrenated phenols; bisphenols; aromatic hydrocarbon resins, especially those containing phenolic groups, such as ethoxylated or propoxylated phenols; adipates; sebacates; phthalates; benzoates; organic phosphates or sulfonates; and sulfamides.

[0086] Alternatively, said non-reactive diluents preferably constitute less than 10% by weight, especially less than 5% or less than 2% by weight, based on the total weight of the composition.

[0087] Methods and Applications The elements are mixed together to produce a defined curable composition. It is important that the mixing results in a uniform dispersion of the components within the composition. Such thorough and effective mixing may determine the uniform distribution of any constituents, particulate fillers or other auxiliary materials within the resulting polymer matrix after curing.

[0088] As is known in the art, to produce a one-component (1K) curable composition, the components of the composition are mixed together homogeneously under conditions that inhibit or prevent reaction of the reactive components. Such conditions would be readily understood by one skilled in the art. Thus, it is often preferred to mechanically mix the curable components (e.g., in a static or dynamic mixer) in predetermined amounts without intentional exposure to light or heat, rather than by hand mixing.

[0089] According to the broadest method embodiment of the invention, the composition is applied to a substrate and then cured in situ. Before applying the composition, it is often recommended to pretreat the relevant substrate surface to remove foreign matter therefrom: if applicable, this step can facilitate adhesion of the subsequent composition to the substrate. Such treatments are known in the art and can be carried out in a single or multi-step process consisting, for example, of using one or more of the following: an etching treatment with an acid suitable for the substrate and optionally an oxidizing agent; ultrasonic treatment; plasma treatment, including chemical plasma treatment, corona treatment, atmospheric plasma treatment and flame plasma treatment; immersion in an aqueous alkaline degreasing bath; treatment with an aqueous cleaning emulsion; treatment with a cleaning solvent, such as acetone, carbon tetrachloride or trichloroethylene; and washing with water, preferably deionized or demineralized water.

[0090] In some embodiments, the adhesion of the composition of the present invention to the preferably pretreated substrate can be promoted by applying a primer thereto.In fact, a primer composition may be necessary to ensure effective adhesion and / or curing time of the composition on an inert substrate.Those skilled in the art can select a suitable primer.

[0091] The composition is then applied to the surface of the substrate, which may be optionally pretreated and optionally primed, by conventional application methods such as: brushing; roll coating; doctor blade application; spraying methods, including but not limited to air-atomized spray, air-assisted spray, airless spray, and high volume low pressure spray; printing methods, including screen printing; pin transfer; and syringe application, including application by electropneumatically controlled syringe. It is recommended that the composition be applied to the surface at a wet film thickness of 10 to 500 μm. Applying thinner layers within this range is more economical and reduces the possibility of harmful thick cured areas. However, careful control must be exercised in applying thinner coatings or layers to avoid the formation of discontinuous cured films.

[0092] When the composition is photochemically cured, the energy source used to initiate curing of the applied composition emits at least one of ultraviolet (UV), infrared (IR), visible light, X-rays, gamma rays, or electron beam (e-beam). After application, when irradiated using commercially available curing equipment, the composition may typically be activated in less than 5 minutes, usually from 1 to 60 seconds, for example from 3 to 12 seconds.

[0093] The ultraviolet light to be irradiated should usually have a wavelength of 150 to 600 nm, preferably 200 to 450 nm. Useful UV light sources include, for example, ultra-high pressure mercury lamps, high pressure mercury lamps, medium pressure mercury lamps, low intensity fluorescent lamps, metal halide lamps, microwave-driven lamps, xenon lamps, UV-LED lamps, and laser light sources such as excimer lasers and argon ion lasers.

[0094] When using an electron beam to cure the applied composition, typical parameters of the operating device can be as follows: accelerating voltage of 0.1-100 keV, 10-10 -3 Vacuum level in Pa, current from 0.0001 to 1 ampere, and power from 0.1 watts to 1 kilowatts.

[0095] The amount of radiation required to sufficiently cure a particular composition (e.g., to set the coating) will depend on a variety of factors, including the angle of exposure to the radiation and the thickness of the applied composition, but generally ranges from 5 to 5000 mJ / cm. 2 A curing dose of 50 to 500 mJ / cm can be cited as typical. 2 , for example 50-400mJ / cm 2 can be considered to be very effective.

[0096] Curing chemistry under light irradiation follows the same laws of thermodynamics as any chemical reaction: reaction rates can be increased by heat or decreased by low temperature. If there are shadow areas on the substrate to which the composition is applied, the temperature of the substrate may be increased above ambient temperature after light irradiation to ensure complete cure of the shadow areas.

[0097] As previously mentioned, the compositions of the present invention may be cured at room temperature. Similarly, the compositions may be affected by increasing the temperature of the composition above room temperature. While not intending to limit the invention, such thermal curing of the applied curable composition should typically occur at a temperature ranging from 50°C to 200°C, preferably 75°C to 175°C or 100°C to 150°C. Where applicable, the temperature of the curable composition may be elevated above the mixing and / or application temperature using conventional means, including microwave induction. The elevated temperature may be maintained for up to 60 minutes to ensure complete curing.

[0098] For completeness, exemplary substrates to which the compositions of the present invention may be applied include: non-ferrous metal substrates such as aluminum, zinc and their alloys; ferrous metals such as iron, stainless steel, cold rolled steel, electrogalvanized steel, and the like; engineering plastics; polyolefins such as polyethylene (PE) and polypropylene (PP), thermoplastics such as polybutylene terephthalate (PBT), polycarbonate (PC) and acrylonitrile butadiene styrene (ABS); paper; cardboard; glass; composites; wood; leather; and combinations thereof.

[0099] It is envisioned that the compositions herein may be useful as coatings, adhesives and sealants, or in the formation of composite structures.

[0100] The following examples are illustrative of the present invention and are not intended to limit the scope of the present invention in any way. EXAMPLES

[0101] The following materials were used in the examples: Ebecryl 3703: a difunctional epoxy acrylate with a molecular weight (Mw) of 850 Daltons, available from Daicel-Allnex Ltd. PTMP: Pentaerythritol tetrakis(3-mercaptopropionate), CAS number: 7575-23-7, available from Sigma Aldrich. TMPTA: Trimethylolpropane triacrylate, CAS number: 15625-89-5, available from Sigma Aldrich.

[0102] Examples 1-2 Compositions were prepared according to Table 1 below. The specified components were mixed in a speed mixer (1200 rpm; 1 minute) to ensure a homogeneous mixture. The molar ratio of thiol groups (-SH) to acrylate groups (H2C=CHC(O)O-) in Example 1 was 0.84:1. The molar ratio of thiol groups (-SH) to acrylate groups (H2C=CHC(O)O-) in Example 2 was 1:1.

[0103] TIFF2024523815000001.tif3274

[0104] The compositions of the examples were subjected to the following tests.

[0105] Viscosity: This was measured within 5 minutes of mixing the composition using a Brookfield viscometer at 25° C. and 50% relative humidity (RH).

[0106] UV Fixation Time: A small drop of the composition was manually placed at room temperature on a clean, dry glass slide (76 x 26 x 1 mm) to prepare a test specimen. A second glass slide was attached to the first at an angle between 30° and 90°. Then, the specimen was exposed to 100 mW / cm2 short wavelength power with peaks at 254 nm and 365 nm. 2 The specimens were cured under a high pressure mercury lamp delivering 10 ...

[0107] Surface cure (UV): The composition was applied to a tack-free glass slide and subjected to UV irradiation with 100 mW / cm of short wavelength power with peaks at 254 nm and 365 nm. 2 The coating was cured under a high pressure mercury lamp delivering 1000 s of energy. The light source was applied for 60 seconds with 5 second intervals.

[0108] Gel Time: In accordance with ASTM Specification D-3451, a sheet of aluminum foil was placed on a hot plate and heated to 120° C. A small amount of the composition was dropped onto the heated foil and the tongue depressor was rubbed over the composition until a continuous, fragile filament was formed when the tongue depressor was lifted from the foil. The elapsed time was measured in seconds.

[0109] Heat Curing: The compositions were heat cured by heating the samples at 120° C. for 15 minutes.

[0110] Room temperature cure: The composition was cured by keeping the sample at 25° C. for 3 days.

[0111] The results and observations of these tests are shown in Table 2 below.

[0112] TIFF2024523815000002.tif63147

[0113] In view of the above description and examples, it will be apparent to one skilled in the art that equivalent modifications may be made without departing from the scope of the claims.

Claims

1. Based on the weight of the dual-curable composition, 10 to 95% by weight of a) at least one epoxy acrylate compound having at least two acrylate groups; and 5 to 90% by weight of b) at least one polythiol compound A dual-curable composition comprising: The composition has a molar ratio of thiol group (-SH) to acrylate group (H ２ C=CHC(O)O-) in the range of 0.2:1 to 1:1, and is characterized by this. The composition is curable at room temperature, under heating, or under light irradiation. Dual-curable composition.

2. Based on the weight of the dual-curable composition, 20 to 90% by weight, preferably 40 to 90% by weight of said a) at least one epoxy acrylate compound having at least two acrylate groups; 10 to 80% by weight, preferably 10 to 60% by weight of said b) at least one polythiol compound; and 0 to 50% by weight, preferably 0 to 30% by weight of c) at least one ethylenically unsaturated non-ionic monomer A dual-curable composition according to claim 1, comprising: The composition has a molar ratio of thiol group (-SH) to acrylate group (H ２ C=CHC(O)O-) in the range of 0.2:1 to 1:1, preferably 0.5:1 to 1:1, and is a dual-curable composition.

3. The dual-curable composition according to claim 1, wherein the at least one epoxy acrylate compound is an adduct of acrylic acid and a polyepoxide compound.

4. The dual-curable composition according to claim 3, wherein the polyepoxide compound has an epoxide equivalent of 100 to 700 g / eq, preferably 120 to 320 g / eq.

5. The dual-curable composition according to claim 3, wherein the polyepoxide compound is selected from the group consisting of polyglycidyl ethers of polyhydric alcohols; polyglycidyl ethers of polyhydric phenols; polyglycidyl esters of polycarboxylic acids; and epoxidized polyethylenically unsaturated hydrocarbons.

6. The dual-curable composition according to claim 3, wherein the polyepoxide compound is a diglycidyl ether selected from the group consisting of diglycidyl ethers of aliphatic and cycloaliphatic diols; bisphenol A-based diglycidyl ethers; bisphenol F diglycidyl ethers; polyalkylene glycol-based diglycidyl ethers; and polycarbonate diol-based glycidyl ethers.

7. The dual-curable composition according to claim 1, wherein the polythiol compound or each polythiol compound contained in the composition has 2 to 5 thiol groups.

8. The polythiol compound or each polythiol compound contained in the composition has a weight average molecular weight (Mw) of less than 20,000 Daltons, preferably 200 to 800 Daltons, and the dual-curable composition according to claim 1.

9. The dual-curable composition according to claim 1, wherein component b) comprises or consists of at least one polyester of thiocarboxylic acid.

10. The dual-curable composition according to claim 9, wherein component b) comprises or consists of at least one compound selected from the group consisting of pentaerythritol tetramercaptoacetate; pentaerythritol tetrakis(3-mercaptopropionate); trimethylolpropane trimercaptoacetate (TMPMP); tris(2-(mercaptopropionyloxy)ethyl) isocyanate; and glycol dimercaptoacetate.

11. The dual-curable composition according to claim 2, comprising 5 to 30% by weight of c) at least one ethylenically unsaturated nonionic monomer.

12. The dual-curable composition according to claim 2, wherein the acrylate monomer constitutes at least 60% by weight, preferably at least 75% by weight, of the total amount of ethylenically unsaturated nonionic monomers present in the composition.

13. The dual-curable composition according to claim 1, substantially free of free radical photoinitiators.

14. The dual-curable composition according to claim 1, substantially free of free radical thermal initiators.

15. Use of the dual-curable composition according to any one of claims 1 to 14 as a coating agent, adhesive or sealant.