Two-component (2K) curable adhesive composition

Abstract

The present invention relates to a curable, peelable two-component adhesive composition comprising: i) a first component comprising a (meth)acrylate monomer, a copolymerizable acid, and an electrolyte; and ii) a second component comprising a first curing agent for the monomer in the first component, a second curing agent for the monomer in the first component, and a solubilizing agent.

Description

Technical Field

[0001] The present invention relates to an adhesive composition that can be peeled off from a coated specific substrate. More specifically, the present invention relates to a curable and peelable two-component (2K) adhesive composition.

Background Art

[0002] Adhesive bonding and polymer coating are generally used in the assembly and finishing of manufactured products. They are used in place of mechanical fasteners such as screws, bolts, and rivets, reducing machining costs and providing adhesion with higher adaptability in the manufacturing process. Adhesive bonding evenly distributes stress, reduces the possibility of fatigue, and blocks the joint from corrosion species.

[0003] Accordingly, although adhesive bonding offers many advantages over mechanical fasteners, when required in actual applications, it tends to be difficult to disassemble the adhesively bonded articles. Removal of the adhesive by mechanical processes such as sandblasting and wire brushing is generally excluded because, for one, the adhesive is placed between the substrates and thus cannot be accessed without damaging the surface of the substrates or is difficult to polish. Decomposition by the application of chemicals and / or high temperatures as disclosed in U.S. Patent No. 4,171,240 (Wong) and U.S. Patent No. 4,729,797 (Linde et al.) may be effective, but it can be time-consuming and complex to implement. Furthermore, the required aggressive chemicals and harsh conditions can damage the separated substrates and render them unsuitable for subsequent applications.

[0004] Taking these problems into consideration, certain authors have attempted to develop a peelable adhesive composition in which a cured composition acts to break the adhesion at the interface between the adhesive and the substrate by passing an electric current.

[0005] U.S. Patent No. 7,465,492 (Gilbert) describes a peelable composition comprising a matrix functionality, a free radical initiator, and an electrolyte, the monomer being selected from the group consisting of acrylic, methacrylic, and combinations thereof, the electrolyte providing the composition with sufficient ionic conductivity to support a Faraday reaction in an adhesion formed between the composition and a conductive surface, whereby the composition can be peeled from the surface.

[0006] U.S. Patent Application Publication No. 2007 / 0269659 (Gilbert) describes an adhesive composition peelable at two interfaces, the composition comprising (i) a polymer and an electrolyte, (ii) facilitating the bonding of two surfaces, and (iii) peeling from both the anode and cathode surfaces in response to a voltage applied across both surfaces to form an anode interface and a cathode interface.

[0007] U.S. Patent Application Publication No. 2008 / 0196828 (Gilbert) describes a hot melt adhesive composition comprising a thermoplastic component and an electrolyte, the electrolyte providing the composition with sufficient ionic conductivity to enable a Faraday reaction in a bond formed between the composition and a conductive surface, thereby enabling the composition to be peeled from the surface.

[0008] International Application Publication No. 2017 / 133864 (Henkel AG & Co. KGaA) describes a method for reversibly bonding a first and a second substrate, wherein at least said first substrate is a non-conductive substrate, and the method comprises: a) coating the surface of the non-conductive substrate with a conductive ink; b) applying an electrically peelable hot melt adhesive composition to the surface of the first substrate and / or the second substrate coated with the conductive ink; c) bringing the first substrate into contact with the second substrate such that the electrically peelable hot melt adhesive composition is interposed between the two substrates; d) forming an adhesive bond between the two substrates to provide an adhesive substrate; e) applying a voltage to the adhesive substrate, thereby substantially weakening the adhesion at at least one interface between the electrically peelable hot melt adhesive composition and the substrate surface.

Prior Art Documents

Patent Documents

[0009]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Summary of the Invention

Problems to be Solved by the Invention

[0010] There is still a technical need to provide an adhesive composition that can be easily applied to the surface of a substrate to be subsequently processed, and that can provide an effective bond within a composite structure including the substrate upon curing, but can be effectively peeled off from these substrates by simply applying a potential to the entire cured adhesive.

Means for Solving the Problems

[0011] According to a first aspect of the present invention, (meth)acrylate monomer, copolymerizable acid, and electrolyte a first component containing the same, a first curing agent for the monomer of the first component, a second curing agent for the monomer of the first component, and solubilizer a second component containing the same A curable and peelable two-component (2K) adhesive composition containing the same is provided.

[0012] The adhesive composition may further contain conductive particles, particularly carbon black and silver particles, which may be disposed in one or both of its first and second components.

[0013] In an important embodiment of the present invention, the two-component adhesive composition is based on the weight of the first component, 20 to 80% by weight, preferably 40 to 75% by weight of the (meth)acrylate monomer, 0.25 to 20% by weight, preferably 6 to 16% by weight of the copolymerizable acid, and 2.5 to 25% by weight, preferably 4 to 23% by weight of the electrolyte a first component containing the same, Based on the weight of the second component, 25 to 75% by weight of the first curing agent, 0.01 to 5% by weight, preferably 0.03 to 1% by weight of the second curing agent, and 20 to 45% by weight, preferably 28 to 40% by weight of the solubilizer a second component containing the same, is included.

[0014] In the first component of the adhesive composition, the copolymerizable acid is preferably selected from the group consisting of methacrylic acid, acrylic acid, itaconic acid, maleic acid, aconitic acid, crotonic acid, fumaric acid, and mixtures thereof, and it is particularly noted that methacrylic acid is selected.

[0015] Separate from or in addition to this reference regarding the selection of the copolymerizable acid of the first component, the electrolyte preferably comprises 1-ethyl-3-methylimidazolium methanesulfonate, 1-ethyl-3-methylimidazolium methylsulfate, 1-hexyl-3-methylimidazolium 2-(2-fluoroanilino)-pyridinate, 1-hexyl-3-methylimidazolium imide, 1-butyl-1-methyl-pyrrolidinium 2-(2-fluoroanilino)-pyridinate, 1-butyl-1-methyl-pyrrolidinium imide, trihexyl(tetradecyl)phosphonium 2-(2-fluoroanilino)-pyridinate, cyclohexyltrimethylammonium bis(trifluoromethylsulfonyl)imide, di(2-hydroxyethyl)ammonium trifluoroacetate, N,N-dimethyl(2-hydroxyethyl)ammonium octanoate, methyltrioctylammonium bis(trifluoromethylsulfonyl)imide, N-ethyl-N-N-N-N-tetramethylguanidinium trifluoromethanesulfonate, guanidinium trifluoromethanesulfonate, 1-butyl-4-methylpyridinium bromide, 1-butyl-3-methylpyridinium tetrafluoroborate, 1-butyl-3-hydroxymethylpyridinium ethylsulfate, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-butyl-methylpyrrolidinium tris(pentafluoroethyl)trifluorophosphate, 3-methylimidazolium ethylsulfate, 1-ethyl-3-methylimidazolium chloride, 1-ethyl-3-ethyl-methylimidazolium bromide, 1-butyl-3-methylimidazolium chloride, 1-hexyl-3-methylimidazolium chloride, 1-octyl-3-methylimidazolium chloride, 1-methyl-3-octylimidazolium chloride, 1-propyl-3-methylimidazolium iodide, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazolium hexafluorophosphate, 1-butyl-2,3-dimethylimidazolium tetrafluoroborate, 1-butyl-2,It is selected from the group consisting of 3-dimethylimidazolium hexafluorophosphate, 1-butylimidazole, 1-methylimidazolium tetrafluoroborate, tetrabutylphosphonium tris(pentafluoroethyl) trifluorophosphate, trihexyl(tetradecyl)phosphonium tetrafluoroborate, and mixtures thereof. The use of at least one of 1-ethyl-3-methylimidazolium methanesulfonate and 1-ethyl-3-methylimidazolium methylsulfate can be said to be particularly preferred.,

[0016] In the second component of the adhesive composition, the first curing agent is preferably a peroxide curing agent selected from the group consisting of tert-butyl peroxide, tert-butyl perbenzoate, cumene hydroperoxide, tert-butyl peroxybenzoate, diacetyl peroxide, benzoyl peroxide, tert-butyl peracetate, lauryl peroxide, and mixtures thereof, and the use of benzoyl peroxide is particularly preferred.

[0017] Separate from or in addition to this mention regarding the selection of the first curing agent, the second curing agent preferably consists of at least one compound that is a salt or a complex of a transition metal selected from the group consisting of Fe, Co, V, Mn, and Cu. More preferably, the second curing agent contains or consists of at least one iron-based compound selected from the group consisting of ferrocene, iron(II) acetylacetonate, and ammonium iron (III) hexakis (cyano-C) ferrate. The selection of ferrocene in particular is noted.

[0018] Apart from or in addition to this reference to the selection of the first and second curing agents, the solubilizer of the second component of the adhesive composition is polyethylene glycol or an epoxy resin selected from the group consisting of alicyclic epoxides, epoxy novolac resins, bisphenol-A-epoxy resins, bisphenol-F-epoxy resins, bisphenol-A epichlorohydrin-based epoxy resins, alkyl epoxides, limonene dioxide, polyepoxides, and mixtures thereof. In particular, the selection of a solubilizer comprising or consisting of bisphenol-A-epoxy resin is noted.

[0019] According to a second aspect of the present invention, a first material layer having a conductive surface, and a second material layer having a conductive surface An adhesive structure is provided, wherein the curable and peelable two-component (2K) adhesive composition defined in the above and the appended claims is disposed between the first material layer and the second material layer.

[0020] According to a third aspect of the present invention, i) a step of applying a voltage across both surfaces to form an anode interface and a cathode interface, and ii) a step of peeling the two surfaces A method of peeling the adhesive structure defined in the above and the appended claims is provided.

[0021] Step i) of this method is preferably a) an applied voltage of 0.5 to 100 V, and b) a voltage applied for 1 second to 60 minutes characterized by at least one of them.

Brief Description of the Drawings

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Mode for Carrying Out the Invention

[0023] <Definition> As used herein, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise.

[0024] As used herein, the terms "comprising" and "comprised of" are synonymous with "including", "includes", "containing" or "contains", are inclusive or open-ended and do not exclude additional, unrecited members, elements, or method steps.

[0025] As used herein, the term "consisting of" excludes elements, components, members, or method steps not specified.

[0026] When a quantity, concentration, dimension, or other parameter is expressed in the form of a range, a preferred range, an upper limit, a lower limit, or a preferred upper limit and a limiting value, any range obtained by combining any upper or preferred value with any lower or preferred value should be understood to be specifically disclosed, whether or not the resulting range is explicitly recited in the context.

[0027] Furthermore, according to standard understanding, a weight range expressed as "0 to x" specifically includes 0 weight%. The component defined by the range may be absent from the composition or may be present in the composition in an amount up to a maximum of x weight%.

[0028] The words "preferred", "preferably", "desirably" and "particularly" are frequently used herein to draw attention to embodiments of the present disclosure that may provide certain benefits under certain circumstances. However, the description of one or more preferred, preferable, desirable, or particular embodiments is not intended to imply that other embodiments are not useful, nor is it intended to exclude those other embodiments from the scope of the present disclosure.

[0029] As used in this application, the word "may" is used in a permissive, not an obligatory, sense; that is, it means there is a possibility.

[0030] As used herein, room temperature is 23 °C plus or minus 2 °C. As used herein, "ambient conditions" means the temperature and pressure surrounding the composition, or the coating layer or the substrate of the coating layer, in which the composition is disposed.

[0031] In the context of the present invention, a "two-component (2K) composition" is understood to be a composition in which the first component (A) and the second component (B) must be stored in separate containers due to their (high) reactivity. The two components are mixed only immediately prior to application and then react to form an adhesive bond and thereby a polymer network, usually without additional activation. Herein, a higher temperature can be applied to accelerate the crosslinking reaction.

[0032] As used herein, the term "detachable" means that, after curing of the adhesive, applying a potential of 10 V to 75 V for 1 second to 60 minutes can reduce the adhesive strength by at least 50%. The cured adhesive is applied between two substrates adhered by the adhesive such that an electric current flows through the adhesive bond line. The adhesive strength is measured by a tensile lap shear (TLS) test based on the determination of the tensile lap shear strength of adhesive assemblies according to EN 1465:2009 (German version) adhesives, performed at room temperature. The overlap area of the adhesion was 25 mm × 10 mm and had an adhesive thickness of approximately 150 μm.

[0033] As used herein, the term "monomer" refers to a substance that can undergo a polymerization reaction and contribute to the structural units of the polymer's chemical structure. The term "monofunctional" as used herein refers to the possession of one polymerizable moiety. The term "polyfunctional" as used herein refers to the possession of multiple polymerizable moieties.

[0034] As used herein, the term "equivalent (eq.)" relates to the relative number of reactive groups present in a reaction, as is common in chemical notation.

[0035] As used herein, the term "electrolyte" is used in accordance with its standard meaning in the art to refer to a substance containing free ions that can conduct electricity by the movement of charged carrier species. This term is intended to encompass molten electrolytes, liquid electrolytes, semi-solid electrolytes, and solid electrolytes, at least one of the cationic or anionic components of their electrolyte structures being essentially free to move and thus acting as charge carriers.

[0036] The curable adhesive composition of the present invention and the cured adhesive obtained therefrom have "electrolyte functionality" in that the adhesive material enables the conduction of either ions, anions or cations, or both. The electrolyte functionality is understood to be derived from the ability of the composition and the cured adhesive to solvate at least one polar ion.

[0037] As used herein, "(meth)acrylic" is a shortened form referring to "acrylic" and / or "methacrylic". Thus, the term "(meth)acrylamide" refers collectively to acrylamide and methacrylamide.

[0038] As used herein, "C1-C n alkyl" group refers to a monovalent group containing from 1 to n carbon atoms. This is a group of alkanes and includes straight-chain and branched-chain organic groups. Thus, "C1-C 30The term "alkyl" refers to a monovalent group containing 1 to 30 carbon atoms, which is a group of alkanes and includes linear 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 an alkyl group may be unsubstituted or substituted with one or more substituents such as halo, nitro, cyano, amide, amino, sulfonyl, sulfinyl, sulfanyl, sulfoxy, urea, thiourea, sulfamoyl, sulfamide, and hydroxy. When applicable, the selection of a given substituent is noted in the specification. However, generally, an alkyl group containing 1 to 18 carbon atoms (C1-C 18 alkyl), for example, an alkyl group containing 1 to 12 carbon atoms (C1-C 12 alkyl) or an alkyl group containing 1 to 6 carbon atoms (C1-C6 alkyl) is noted as being selected.

[0039] As used herein, the term "C1-C 18 hydroxyalkyl" refers to an HO-(alkyl) group having 1 to 18 carbon atoms, where the point of attachment of the substituent is via an oxygen atom and the alkyl group is as defined above.

[0040] "Alkoxy group" refers to a monovalent group represented by -OA (where A is an alkyl group), and non-limiting examples thereof are a methoxy group, an ethoxy group, and an isopropyloxy group. As used herein, the term "C1-C 18 alkoxyalkyl" refers to an alkyl group having an alkoxy substituent as defined above and containing a total of 1 to 18 carbon atoms in the (alkyl-O-alkyl) moiety. Such groups include methoxymethyl (-CH2OCH3), 2-methoxyethyl (-CH2CH2OCH3), and 2-ethoxyethyl.

[0041] As used herein, the term "C2-C4 alkylene" is defined as a saturated divalent hydrocarbon group having 2 to 4 carbon atoms.

[0042] The term "C3-C 30 cycloalkyl" is understood to mean a saturated, monocyclic, bicyclic or tricyclic hydrocarbon group having 3 to 30 carbon atoms, which may be substituted. Generally, preference is given to cycloalkyl groups (C3-C 18 cycloalkyl groups) containing 3 to 18 carbon atoms. Examples of cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, adamantane, and norbornane.

[0043] As used herein, a "C6-C 18 aryl" group, used alone or as part of a larger moiety, such as in an "aralkyl group", refers to a monocyclic, bicyclic and tricyclic ring system, which may be substituted, wherein 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- to 3-membered carbocyclic rings. Exemplary aryl groups include phenyl; (C1-C4)alkylphenyl, such as tolyl and ethylphenyl; indenyl; naphthalenyl, tetrahydronaphthyl, tetrahydroindenyl; tetrahydroanthracenyl; and anthracenyl. Preference may be given to the selection of a phenyl group.

[0044] As used herein, "C2-C 20 alkenyl" refers to a hydrocarbyl group having 2 to 20 carbon atoms and at least one unit of ethylenic unsaturation. The alkenyl group may be straight-chain, branched-chain or cyclic and may be substituted. The term "alkenyl" also includes groups having "cis" and "trans" configurations, or "E" and "Z" configurations, as understood by those skilled in the art. However, generally, 2 to 10 (C 2-10 ) or 2 to 8 (C 2-8) The selection of an unsubstituted alkenyl group containing carbon atoms is remarkable. The C2-C 12 Examples of the alkenyl group include, but are not limited to, -CH=CH2; -CH=CHCH3; -CH2CH=CH2; -C(=CH2)(CH3); -CH=CHCH2CH3; -CH2CH=CHCH3; -CH2CH2CH=CH2; -CH=C(CH3)2; -CH2C(=CH2)(CH3); -C(=CH2)CH2CH3; -C(CH3)=CHCH3; -C(CH3)CH=CH2; -CH=CHCH2CH2CH3; -CH2CH=CHCH2CH3; -CH2CH2CH=CHCH3; -CH2CH2CH2CH=CH2; -C(=CH2)CH2CH2CH3; -C(CH3)=CHCH2CH3; -CH(CH3)CH=CHCH; -CH(CH3)CH2CH=CH2; -CH2CH=C(CH3)2; 1-cyclopent-1-enyl; 1-cyclopent-2-enyl; 1-cyclopent-3-enyl; 1-cyclohex-1-enyl; 1-cyclohex-2-enyl; and 1-cyclohexyl-3-enyl.

[0045] As used herein, "alkylaryl" refers to an alkyl-substituted aryl group, and "substituted alkylaryl" refers to an alkylaryl group further having one or more substituents as described above. Further, as used herein, "aralkyl" means an alkyl group substituted with an aryl group as defined above.

[0046] The term "hetero" as used herein refers to a group or moiety containing one or more heteroatoms such as N, O, Si, and S. Thus, for example, "heterocyclic" refers to a cyclic group having, for example, N, O, Si, or S as part of the ring structure. "Heteroalkyl", "heterocycloalkyl", and "heteroaryl" moieties are, respectively, the alkyl group, cycloalkyl group, and aryl group as defined above that contain N, O, Si, or S as part of their structures.

[0047] As used herein, the term "equivalent weight" means the molecular weight divided by the number of corresponding functional groups. Thus, "epoxy equivalent weight" (EEW) means the weight in grams of a resin containing 1 equivalent of epoxy.

[0048] As used herein, the term "epoxide" refers to a compound characterized by the presence of at least one cyclic ether group, i.e., a group in which an ether oxygen atom is bonded to two adjacent carbon atoms, thereby forming a cyclic structure. This term is intended to encompass monoepoxide compounds, polyepoxide compounds (having two or more epoxide groups), and epoxide-terminated prepolymers. The term "monoepoxide compound" means an epoxide compound having one epoxide group. The term "polyepoxide compound" means an epoxide compound having at least two epoxide groups. The term "diepoxide compound" means an epoxide compound having two epoxide groups.

[0049] The epoxide may be unsubstituted or may be inertly substituted. Exemplary inert substituents include chlorine, bromine, fluorine, and phenyl.

[0050] The molecular weights referred to in this specification can be measured by gel permeation chromatography (GPC) using polystyrene calibration standards as performed in accordance with ASTM 3536.

[0051] Unless otherwise specified, the viscosity of the compositions described herein is measured using an Anton Paar viscometer, model MCR301, under standard conditions of 25°C and 50% relative humidity (RH). The viscometer is calibrated once a year and inspected by service. The calibration is performed using special oils of known viscosities varying from 5,000 cps to 50,000 cps (parallel plates PP25 and shear rate of 1 / s at 23°C). The measurements of the compositions of the present invention are performed using parallel plates PP20 at different shear rates from 1.5 (1 / s) to 100 (1 / s).

[0052] <First Component of Two-Component (2K) Composition> The first component of the two-component (2K) composition contains a (meth)acrylate monomer, a copolymerizable acid, and an electrolyte.

[0053] ≪(Meth)acrylate Monomer≫ The first component of the composition contains a (meth)acrylate monomer typically present in an amount of 20 to 80% by weight, based on the weight of the first component. The (meth)acrylate monomer preferably constitutes 40 to 75% by weight, such as 47 to 68% by weight or 53 to 60% by weight, of the first component.

[0054] An amount exceeding 80% may have an adverse effect on the initial adhesion and peeling effect, while a small amount, mainly less than 20%, may lead to a decrease in the initial adhesion. Therefore, the above-mentioned amount of the (meth)acrylate monomer is preferred.

[0055] There is no particular intention to limit the (meth)acrylate esters useful in this specification, and the (meth)acrylate monomer can be considered to be any ester of acrylic acid or methacrylic acid known in the art. However, exemplary (meth)acrylic monomers include, but are not limited to:

[0056] · C1-C of meth(acrylic acid) 18 alkyl esters, such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate (all isomers), hexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-nonyl (meth)acrylate, n-decyl (meth)acrylate, n-dodecyl (meth)acrylate, and n-stearyl (meth)acrylate; · C3-C of meth(acrylic acid) 18Cycloalkyl esters, such as cyclohexyl (meth)acrylate and isobornyl (meth)acrylate, etc.; · C6-C of meth(acrylic acid) 18 Aryl esters, such as phenyl (meth)acrylate and tolyl (meth)acrylate, etc.; · C7-C of meth(acrylic acid) 24 Aralkyl esters, such as benzyl (meth)acrylate, etc.; · C1-C of meth(acrylic acid) 18 Alkoxyalkyl esters, such as 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, and 3-methoxybutyl (meth)acrylate, etc.; · Fluorine-containing C1-C of meth(acrylic acid) 18 Alkyl esters, such as trifluoromethylmethyl (meth)acrylate, 2-trifluoromethylethyl (meth)acrylate, 2-perfluoroethylethyl (meth)acrylate, 2-perfluoroethyl-2-perfluorobutylethyl (meth)acrylate, 2-perfluoroethylethyl (meth)acrylate, perfluoromethyl (meth)acrylate, dipentafluoromethylmethyl (meth)acrylate, 2-perfluoromethyl-2-perfluoroethylmethyl (meth)acrylate, 2-perfluorohexylethyl (meth)acrylate, 2-perfluorodecylethyl (meth)acrylate, and 2-perfluorohexadecylethyl (meth)acrylate, etc.; · C1-C of (meth)acrylic acid 18 Hydroxyalkyl esters, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and pentaerythritol tri(meth)acrylate, etc.; · Di / polyester of di / polyfunctional alcohols, such as ethylene glycol di(meth)acrylate, 1,3 or 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, etc.; · C1-C of (meth)acrylic acid 18Aminoalkyl esters, such as 2-aminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, and (meth)acryloyloxyethoxyethylamine; · C1-C of (meth)acrylic acid 18 Alkoxysilyl-containing alkyl esters, such as γ-(meth)acryloyloxypropyltrimethoxysilane; · Ethylene oxide or propylene oxide adducts of (meth)acrylic acid; and · (Meth)acrylate esters formed by alcohols having other functional groups, such as tetrahydrofurfuryl (meth)acrylate.

[0057] To complete, it is not excluded that the first component of the composition comprises a macromonomer component consisting of one or more oligomers selected from the group consisting of urethane (meth)acrylate, polyester (meth)acrylate, and polyether (meth)acrylate. However, although it can be monofunctional or polyfunctional with respect to the polymerizable (meth)acrylate functional group, such oligomeric compounds based on repeating urethane, ester, and ether subunits should generally not be constituted by more than 30% by weight of the total (meth)acrylate monomers in the above first component.

[0058] As is known in the art, urethane (meth)acrylate oligomers can be prepared by the reaction of a polyfunctional (meth)acrylate having a hydroxyl group with the polyisocyanate defined above herein. In particular, the polyfunctional (meth)acrylate having a hydroxyl group can be selected from the group consisting of 2-hydroxyethyl (meth)acrylate; 2-hydroxyisopropyl (meth)acrylate; 4-hydroxybutyl (meth)acrylate; hydroxyethyl caprolactone (meth)acrylate; pentaerythritol tri(meth)acrylate; pentaerythritol tetra(meth)acrylate; dipentaerythritol penta(meth)acrylate; dipentaerythritol hexa(meth)acrylate; and combinations thereof.

[0059] Suitable polyester (meth)acrylate oligomers are obtained by reacting (meth)acrylic acid with a polyester prepared from a polybasic acid or its anhydride and a polyhydric alcohol. 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.

[0060] As is known in the art, polyether (meth)acrylate oligomers can be obtained by a transesterification reaction between a polyether and a (meth)acrylate ester such as ethyl methacrylate. Exemplary polyethers include polyethers obtained from ethoxylated or propoxylated trimethylolpropane, pentaerythritol, etc., or polyethers obtained by polyetherification of 1,4 - propanediol, etc.

[0061] In a preferred embodiment, the first component comprises at least one (meth)acrylate monomer selected from the group consisting of: methyl (meth)acrylate; ethyl (meth)acrylate; n-propyl (meth)acrylate; isopropyl (meth)acrylate; n-butyl (meth)acrylate; isobutyl (meth)acrylate; tert-butyl (meth)acrylate; n-pentyl (meth)acrylate; n-hexyl (meth)acrylate; cyclohexyl (meth)acrylate; n-heptyl (meth)acrylate; n-octyl (meth)acrylate; 2-ethylhexyl-(meth)acrylate; nonyl (meth)acrylate; decyl (meth)acrylate; dodecyl (meth)acrylate; phenyl (meth)acrylate; tolyl (meth)acrylate; benzyl (meth)acrylate; 2-methoxyethyl (meth)acrylate; 3-methoxybutyl (meth)acrylate; 2-hydroxyethyl (meth)acrylate; 2-hydroxypropyl (meth)acrylate; stearyl (meth)acrylate; glycidyl (meth)acrylate; isobornyl (meth)acrylate; 2-aminoethyl (meth)acrylate; γ-(meth)acryloyloxypropyltrimethoxysilane; (meth)acrylic acid-ethylene oxide adduct; trifluoromethylmethyl (meth)acrylate; 2-trifluoromethylethyl (meth)acrylate; 2-perfluoroethylethyl (meth)acrylate; 2-perfluoroethyl-2-perfluorobutylethyl (meth)acrylate; 2-perfluoroethylethyl (meth)acrylate; perfluoromethyl (meth)acrylate; dipentafluoroethylmethyl (meth)acrylate; 2-perfluoromethyl-2-perfluoroethylmethyl (meth)acrylate; 2-perfluorohexylethyl (meth)acrylate; 2-perfluorodecylethyl (meth)acrylate; 2-perfluorohexadecylethyl (meth)acrylate; ethoxylated trimethylolpropane triacrylate; trimethylolpropane trimethacrylate; dipentaerythritol monohydroxypentaacrylate; pentaerythritol triacrylate; ethoxylated trimethylolpropane triacrylate; 1,6-hexanediol diacrylate;Neopentyl glycol diacrylate; pentaerythritol tetraacrylate; 1,2-butylene glycol diacrylate; trimethylolpropane ethoxylate tri(meth)acrylate; glyceryl propoxylate tri(meth)acrylate; trimethylolpropane tri(meth)acrylate; dipentaerythritol monohydroxy penta(meth)acrylate; tripropylene glycol di(meth)acrylate; neopentyl glycol propoxylate di(meth)acrylate; 1,4-butanediol di(meth)acrylate; triethylene glycol di(meth)acrylate; butylene glycol di(meth)acrylate; and ethoxylated bisphenol A di(meth)acrylate.;

[0062] Good results were obtained when the first component included at least one (meth)acrylate monomer selected from the group consisting of methyl (meth)acrylate, ethyl (meth)acrylate, isobornyl (meth)acrylate, ethoxylated trimethylolpropane triacrylate and trimethylolpropane triacrylate, and mixtures thereof.

[0063] The above (meth)acrylate monomers are preferred because the size of the monomers results in the formation of an ideal polymer network, which is considered to increase ion transport.

[0064] ≪Copolymerizable acid≫ As described above, the first component of the composition includes a copolymerizable acid typically used in an amount of 0.25 to 20% by weight based on the weight of the first component: the copolymerizable acid may preferably constitute 6 to 16% by weight, for example 10 to 13% by weight of the first component. For the sake of completeness, such monomers are typically preferably used in the form of the free acid, but the fact that the constituent acid groups of the monomers are partially or completely neutralized with a suitable base is not excluded if this does not impair their participation in the copolymerization.

[0065] An amount exceeding 20% may cause corrosion problems and gas generation, while if the amount is small, curing may be incomplete and the initial adhesiveness may decrease. Therefore, the amount of the copolymerizable acid described above is preferred.

[0066] Without intending to limit the present invention, the copolymerizable acid monomer is preferably selected from ethylenically unsaturated carboxylic acids; ethylenically unsaturated sulfonic acids; and vinylphosphonic acids. Suitable ethylenically unsaturated sulfonic acids are, for example, vinylsulfonic acid, styrenesulfonic acid, and acrylamidomethylpropanesulfonic acid.

[0067] Preferably, the copolymerizable acid of this component contains or consists of ethylenically unsaturated carboxylic acids 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. In particular, the copolymerizable acid of this component contains or consists of at least one acid selected from methacrylic acid, acrylic acid, itaconic acid, maleic acid, aconitic acid, crotonic acid, and fumaric acid.

[0068] The applicant has found that the copolymerizable acid improves the curing rate and metal adhesiveness of the composition.

[0069] The present invention can be copolymerized with (meth)acrylate monomers, and styrene monomers such as styrene, vinyltoluene, α-methylstyrene, and chlorostyrene; fluorine-containing vinyl monomers such as perfluoroethylene, perfluoropropylene, and fluorinated vinylidene; 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. It should be noted that the presence of vinyl monomers selected from the group consisting of is not excluded from the first component. However, when included, such vinyl comonomers preferably constitute less than 40% by weight, preferably less than 20% by weight or less than 10% by weight, based on the total weight of the copolymerizable acid monomers.

[0070] ≪Electrolyte≫ The first component of the composition contains 2.5 to 25% by weight of an electrolyte based on the weight of the first component. The electrolyte may preferably constitute 4 to 23% by weight, for example, 5 to 20% by weight of the first component.

[0071] When the amount of the electrolyte exceeds 25%, it may bring about a good peeling effect, but curing may become incomplete and may have an adverse effect on the initial adhesiveness. On the other hand, a small amount may result in a lack of peeling effect. Therefore, the above amount is preferred.

[0072] The electrolyte preferably contains at least one salt having a formula selected from the group consisting of the following. [Chemical formula] (In the formula, R 1 , R 2 , R 3 , R 4 , R 5 and R 6 are independently selected from hydrogen, C1-C 18 alkyl, C3-C 18 cycloalkyl, C6-C 18 aryl, C7-C 24 aralkyl, C2-C 20 alkenyl, -C(O)R q , -C(O)OH, -CN and -NO2, and R q is C1-C6 alkyl.)

[0073] To be complete, the terms C1-C 18 alkyl, C3-C 18 cycloalkyl, C6-C 18 aryl, C7-C 24 aralkyl, C2-C 20 alkenyl explicitly include groups in which one or more hydrogen atoms are substituted with halogen atoms (e.g., C1-C 18 haloalkyl) or groups substituted with hydroxyl groups (e.g., C1-C 18 hydroxyalkyl). In particular, R 1 , R 2 , R 3 , R 4 , R 5 and R 6 are preferably independently selected from hydrogen, C1-C 12 alkyl, C1-C 12 haloalkyl, C1-C 12 hydroxyalkyl and C3-C 12 cycloalkyl. For example, R 1 , R 2 , R 3 , R 4 , R 5 and R 6may be independently selected from hydrogen, C1-C6 alkyl, C1-C6 haloalkyl, and C1-C6 hydroxyalkyl.

[0074] There is no particular intention to limit the counteranion (X - ) that can be used in the electrolyte. Exemplary anions can be selected from the following. · Halides; · The formula PF6 - , CF3SO3 - , (CF3SO3)2N - , CF3CO2 - and CCl3CO2 - pseudohalides and halogen-containing compounds; · CN - , SCN - and OCN - ; · Phenates; · The general formula SO4 2- , HSO4 - , SO3 2- , HSO3 - , R a OSO3 - and R a SO3 - sulfates, sulfites, and sulfonates; · The general formula PO4 3- , HPO4 2- , H2PO4 - , R a PO4 2- , HR a PO4 - and R a R b PO4 - phosphates; · The general formula R a HPO3 - , R a R b PO2 - , and R a R b PO3 - phosphonates and phosphinates; · The general formula PO3 3- , HPO3 2- , H2PO3- , R a PO3 2- , R a HPO3 - and R a R b PO3 - phosphites; · General formula R a R b PO2 - , R a HPO2 - , R a R b PO - and R a HPO - phosphonites and phosphinites; · General formula R a COO - carboxylate anions; · Hydroxycarboxylate anions and saccharate anions; · Saccharinate (salt of o-benzoic sulfimide); · General formula BO3 3- , HBO3 2- , H2BO3 - , R a R b BO3 - , R a HBO3 - , R a BO3 2- , B(OR a )(OR b )(OR c )(OR d ) - , B(HSO4) - and B(R a SO4) - borates; · General formula R a BO2 2- and R a R b BO - boronates; · General formula HCO3 - , CO3 2- and R a CO3 - carbonates and carbonic esters; · General formula SiO44- , HSiO4 3- , H2SiO4 2- , H3SiO4 - , R a SiO4 3- , R a R b SiО4 2- , R a R b R c SiO4 - , HR a SiO4 2- , H2R a SiO4 - and HR a , R b SiO4 - silicates and silicic acid esters of; · General formula R a SiO3 3- , R a R b SiO2 2- , R a R b R c SiO - , R a R b R c SiO3 - , R a R b R c SiO2 - and R a R b SiO3 2- alkyl and aryl silanolates of; · Pyridinates and pyrimidinates; · General formula:

Chem.

Chem.

[0075] Based on the definitions in the above list, preferred anions are the halides, pseudohalides and halogen-containing compounds defined above; carboxylate anions, especially formate, acetate, propionate, butyrate and lactate; hydroxycarboxylate anions; pyridinates and pyrimidinates; carboxylic acid imides, bis(sulfonyl)imides and sulfonylimides; sulfates, especially methyl sulfate and ethyl sulfate; sulfites; sulfonates, especially methanesulfonate; and phosphates, especially dimethyl phosphate, diethyl phosphate and di-(2-ethylhexyl)-phosphate, selected from the group consisting of.

[0076] The electrolyte of the first component is preferably 1-ethyl-3-methylimidazolium methanesulfonate, 1-ethyl-3-methylimidazolium methylsulfate, 1-hexyl-3-methylimidazolium 2-(2-fluoroanilino)-pyridinate, 1-hexyl-3-methylimidazolium imide, 1-butyl-1-methyl-pyrrolidinium 2-(2-fluoroanilino)-pyridinate, 1-butyl-1-methyl-pyrrolidinium imide, trihexyl(tetradecyl)phosphonium 2-(2-fluoroanilino)-pyridinate, cyclohexyltrimethylammonium bis(trifluoromethylsulfonyl)imide, di(2-hydroxyethyl)trifluoroammonium acetate, N,N-dimethyl(2-hydroxyethyl)ammonium octanoate, methyltrioctylammonium bis(trifluoromethylsulfonyl)imide, N-ethyl-N-N-N-N-tetramethylguanidinium trifluoromethanesulfonate, guanidinium trifluoromethanesulfonate, 1-butyl-4-methylpyridinium bromide, 1-butyl-3-methylpyridinium tetrafluoroborate, 1-butyl-3-hydroxymethylpyridinium ethylsulfate, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-butyl-methylpyrrolidinium tris(pentafluoroethyl)trifluorophosphate, 3-methylimidazolium ethylsulfate, 1-ethyl-3-methylimidazolium chloride, 1-ethyl-3-ethyl-methylimidazolium bromide, 1-butyl-3-methylimidazolium chloride, 1-hexyl-3-methylimidazolium chloride, 1-octyl-3-methylimidazolium chloride, 1-methyl-3-octylimidazolium chloride, 1-propyl-3-methylimidazolium iodide, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazolium hexafluorophosphate, 1-butyl-2,3-dimethylimidazolium tetrafluoroborate, 1-butyl-2,It is selected from the group consisting of 3-dimethylimidazolium hexafluorophosphate, 1-butylimidazole, 1-methylimidazolium tetrafluoroborate, tetrabutylphosphonium tris(pentafluoroethyl) trifluorophosphate, trihexyl(tetradecyl)phosphonium tetrafluoroborate, and mixtures thereof. It is particularly preferable to use at least one of 1-ethyl-3-methylimidazolium methanesulfonate and 1-ethyl-3-methylimidazolium methyl sulfate.,

[0077] <The second component of the two-component (2K) composition> The second component of the two-component composition includes a first curing agent, a second curing agent, and a solubilizing agent. The first curing agent

[0078] As described above, the second component of the composition includes a first curing agent typically used in an amount of 25 to 75% by weight based on the weight of the second component. The first curing agent may preferably constitute 50 to 75% by weight of the second component, such as 55 to 70% by weight or 60 to 70% by weight or 61 to 65% by weight. Alternatively, the first curing agent may preferably constitute 25 to 60% by weight, such as 30 to 55% by weight or 30 to 45% by weight.

[0079] When the amount exceeds 75%, the first curing agent may be excessive, and undesirable reactions may adversely affect the properties of the composition. On the other hand, when the amount is small, mainly less than 25%, curing may be incomplete and the initial adhesiveness may be poor. Therefore, the above amount of the first curing agent is preferable.

[0080] In an important embodiment, the first curing agent comprises or consists of at least one free radical initiator that decomposes under the action of heat to provide free radicals. Exemplary heat-activated free radical initiators include peroxides such as ketone peroxides; hydroperoxides; peroxycarbonates; peracetic acid; azo compounds such as 2,2'-azobisisobutyronitrile (AIBN) or 2,2'-azobis(2,4-dimethylpentanenitrile), 4,4'-azobis(4-cyanovaleric acid), or 1,1'-azobis(cyclohexanecarbonitrile); tetrazine; and persulfate compounds such as potassium persulfate. A free radical initiator that is solid at room temperature is preferred. Alternatively, or in addition to those described as preferred, it is desirable for the free radical initiator to have a half-life of at least 10 hours at a temperature of 60 °C.

[0081] Certain peroxides such as dialkyl and diaryl peroxides have been disclosed as useful curing agents, inter alia, in U.S. Patent No. 3,419,512 (Lees) and U.S. Patent No. 3,479,246 (Stapleton) and are in fact useful herein, but hydroperoxides also represent an important class of curing agents for the present invention. In this connection, hydrogen peroxide itself can be used, but it is preferred to use organic hydroperoxides. For completeness, the definition of hydroperoxides includes materials such as organic peroxides or organic peresters that decompose or hydrolyze in situ to form organic hydroperoxides. Examples of such peroxides and peresters are cyclohexyl and hydroxycyclohexyl peroxides and t-butyl perbenzoate, respectively.

[0082] Without intending to limit the present invention, representative hydroperoxide compounds have the general formula:

Chemical formula

[0083] As exemplary compounds that can be used alone or in combination as the first curing agent, cumene hydroperoxide (CHP); paramethane hydroperoxide; t-butyl hydroperoxide (TBH); t-butyl perbenzoate; t-butyl peracetate; t-amyl hydroperoxide; 1,2,3,4-tetramethylbutyl hydroperoxide; lauryl peroxide; benzoyl peroxide (dibenzoyl peroxide, C 14 H 10 O4, also known as CAS No. 94-36-0); 1,3-bis(t-butylperoxyisopropyl)benzene; diacetyl peroxide; butyl 4,4-bis(t-butylperoxy)valerate; p-chlorobenzoyl peroxide; t-butyl cumyl peroxide; di-t-butyl peroxide; dicumyl peroxide; 2,5-dimethyl-2,5-di-t-butylperoxyhexane; 2,5-dimethyl-2,5-di-t-butyl-peroxyhex-3-yne; and 4-methyl-2,2-di-t-butylperoxypentane may be mentioned.

[0084] <<Second Curing Agent>> As described above, the second component of the composition contains a second curing agent typically used in an amount of 0.01 to 5% by weight based on the weight of the second component. The second curing agent preferably may constitute 0.01 to 1% by weight of the second component, for example, 0.03 to 1% by weight or 0.05 to 0.3% by weight.

[0085] An amount exceeding 5% may have an adverse effect on the peeling effect, while a small amount, mainly less than 0.01%, may cause a decrease in the initial adhesiveness. Therefore, the amount of the second curing agent described above is preferred.

[0086] The second curing agent is included in the composition to enhance at least one of the curing rate, adhesive strength, and adhesive quality of the adhesive composition.

[0087] In an important embodiment, the second curing agent comprises, or consists of, at least one compound that is a salt or complex of a transition metal, and this transition metal is selected from the group consisting of Fe, Co, V, Ti, Mn, Cu, Sn, Cr, Ni, Mo, Ge, Sr, Pd, Pt, Nb, Sb, Re, Os, Ir, Pt, Au, Hg, Te, Rb, and Bi, and preferably is selected from the group consisting of Fe, Co, V, Mn, and Cu.

[0088] It has been shown to be advantageous for the second agent to comprise, or consist of, at least one iron compound selected from the group consisting of iron carboxylates, 1,3-dioxoiron complexes; ammonium ferricyanide [hexakis(cyano-C)ferrate(4 - ) ammonium iron(3 + ); and dicyclopentadienyliron complexes. Exemplary iron carboxylates in this regard include iron lactate, iron naphthenate, iron 2-ethylhexanoate (iron octanoate), iron formate, iron acetate, iron propionate, iron butyrate, iron pentanoate, iron hexanoate, iron heptanoate, iron nonanoate, iron decanoate, iron neodecanoate, and iron dodecanoate. Exemplary 1,3-dioxoiron complexes include iron acetylacetonate, and iron complexes of acetylacetone, benzoylacetone, dibenzoylmethane, and acetetoacetates such as diethylacetoacetamide, dimethylacetoacetamide, dipropylacetoacetamide, dibutylacetoacetamide, methyl acetoacetate, ethyl acetoacetate, propyl acetoacetate, and butyl acetoacetate. Examples of dicyclopentadienyliron complexes are complexes containing iron and two substituted or unsubstituted cyclopentadienyl ligands, and any substituent on the cyclopentadienyl ring is C1-C 12 alkyl, C6-C 18 aryl, and C7-C 18It is selected from the group consisting of aralkyl groups. A specific example of the dicyclopentadienyl iron complex is ferrocene (bis(η5-cyclopentadienyl)iron).

[0089] It should be noted that both ferrous (II) and ferric (III) complexes can be used. Furthermore, it can be said that the use of ferrocene as at least a part of the second curing agent is particularly preferred.

[0090] Among the second curing agents, or as further exemplary transition metal compounds that can be used as the second curing agent, salts and complexes of copper, cobalt, vanadium and manganese can be specifically mentioned. In this specification, cobalt compounds can be used as transition metals without legislative and toxicity problems because of the small amount used. Suitable counter anions present in the salts include halides; nitrates; sulfates; sulfonates; phosphates, phosphonates; oxides; or carboxylates such as lactate, 2-ethylhexanoate, acetate, propionate, butyrate, oxalate, laurate, oleate, linoleate, palmitate, stearate, acetylacetonate, octanoate, nonanoate, heptanoate, neodecanoate or naphthenate.

[0091] ≪Solubilizer≫ The second component of the two-component (2K) composition necessarily contains a solubilizer that conventionally exists in an amount of 20 to 45% by weight based on the weight of the second component. Preferably, the solubilizer constitutes 28 to 40% by weight, for example, 35 to 38% by weight of the second component. The solubilizer has the function of promoting the miscibility of electrolytes in the adhesive composition formed upon mixing of the two components. The solubilizer may or may not form part of the polymer matrix formed upon curing of the adhesive composition, but plays a role in promoting ion migration therein. The solubilizer itself is preferably a polar compound and desirably should be liquid at room temperature.

[0092] Amounts exceeding 45% may have an adverse effect on adhesion and curing properties, while on the other hand, small amounts, mainly less than 20%, may cause the second component of the composition to solidify and prevent mixing of the first and second components. Therefore, the amount of the solubilizer described above is preferred.

[0093] In a first embodiment, the solubilizer comprises or consists of one or more liquid epoxy resins. Epoxy resins used herein can include monofunctional epoxy resins, polyfunctional (multi- or polyfunctional) epoxy resins, and combinations thereof. The epoxy resin may be a pure compound, but may also be a mixture of epoxy-functional compounds such as a mixture of compounds having different numbers of epoxy groups per molecule. The epoxy resin may be saturated or unsaturated, aliphatic, alicyclic, aromatic or heterocyclic, and may be substituted. Further, the epoxy resin may be a monomer or a polymer.

[0094] Without intending to limit the present invention, exemplary monoepoxide compounds include the following. Alkylene oxides; epoxy-substituted alicyclic hydrocarbons such as cyclohexene oxide, vinylcyclohexene monooxide, (+)-cis-limonene oxide, (+)-cis,trans-limonene oxide, (-)-cis,trans-limonene oxide, cyclooctene oxide, cyclododecene oxide, and α-pinene oxide; epoxy-substituted aromatic hydrocarbons; monoepoxy-substituted alkyl ethers of monohydric alcohols or phenols such as glycidyl ethers of aliphatic, alicyclic, and aromatic alcohols; monoepoxy-substituted alkyl esters of monocarboxylic acids such as glycidyl esters of aliphatic, alicyclic, and aromatic monocarboxylic acids; monoepoxy-substituted alkyl esters of polycarboxylic acids in which other carboxy groups are esterified with alkanols; alkyl and alkenyl esters of epoxy-substituted monocarboxylic acids; epoxyalkyl ethers of polyhydric alcohols in which other OH groups are esterified or etherified with carboxylic acids or alcohols; and monoesters of polyhydric alcohols and epoxy monocarboxylic acids in which other OH groups are esterified or etherified with carboxylic acids or alcohols.

[0095] As an example, the following glycidyl ethers can be mentioned as monoepoxide compounds suitable for use in this specification. Methyl glycidyl ether; ethyl glycidyl ether; propyl glycidyl ether; butyl glycidyl ether; pentyl glycidyl ether; hexyl glycidyl ether; cyclohexyl glycidyl ether; octyl glycidyl ether; 2-ethylhexyl glycidyl ether; allyl glycidyl ether; benzyl glycidyl ether; phenyl glycidyl ether; 4-tert-butylphenyl glycidyl ether; 1-naphthyl glycidyl ether; 2-naphthyl glycidyl ether; 2-chlorophenyl glycidyl ether; 4-chlorophenyl glycidyl ether; 4-bromophenyl glycidyl ether; 2,4,6-trichlorophenyl glycidyl ether; 2,4,6-tribromophenyl glycidyl ether; pentafluorophenyl glycidyl ether; o-cresyl glycidyl ether; m-cresyl glycidyl ether; and p-cresyl glycidyl ether.

[0096] In certain embodiments, the monoepoxide compound conforms to the following formula (I) herein.

Chemical formula

[0097] R w , R x and R y are hydrogen, and R zis preferably a phenyl group or a C1-C8 alkyl group, more preferably a C1-C4 alkyl group.

[0098] In view of these embodiments, exemplary monoepoxides include ethylene oxide, 1,2-propylene oxide (propylene oxide); 1,2-butylene oxide; cis-2,3-epoxybutane; trans-2,3-epoxybutane; 1,2-epoxypentane; 1,2-epoxyhexane; 1,2-heptylene oxide; decene oxide; butadiene oxide; isoprene oxide; and styrene oxide.

[0099] In the present invention, mention is made of using at least one monoepoxide compound selected from the group consisting of ethylene oxide; propylene oxide; cyclohexene oxide; (+)-cis-limonene oxide (+)-cis, trans-limonene oxide; (-) cis, trans-limonene oxide; cyclooctene oxide; and cyclododecene oxide.

[0100] Again, without intending to limit the present invention, suitable polyepoxy compounds can be liquids, solids, or solutions in a solvent. Further, such polyepoxide compounds should have an epoxy equivalent of 100 to 700 g / eq, for example, 120 to 320 g / eq. Further, generally, diepoxide compounds having an epoxy equivalent of less than 500 g / eq, and further less than 400 g / eq are preferred. This is mainly from the perspective of cost, because in their production, etc., low molecular weight epoxy resins require more limited treatment in purification.

[0101] Examples of the types or groups of polyepoxy compounds that can be polymerized in the present invention include glycidyl ethers of polyhydric alcohols and polyhydric phenols; glycidyl esters of polycarboxylic acids; and epoxidized polyethylene-based unsaturated hydrocarbons, esters, ethers, and amides.

[0102] Suitable diglycidyl ether compounds can be inherently aromatic, aliphatic, or alicyclic and can thus be derived from dihydric phenols and dihydric alcohols. And useful classes of such diglycidyl ethers are diglycidyl ethers of aliphatic and alicyclic 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; polyalkylene glycol-based diglycidyl ethers, particularly, polypropylene glycol diglycidyl ether; and, polycarbonate diol-based glycidyl ethers.

[0103] Further exemplary polyepoxy 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.

[0104] The glycidyl esters of polycarboxylic acids useful in the present invention are derived from polycarboxylic acids containing at least two carboxylic acid groups and no other groups reactive with epoxide groups. The polycarboxylic acids can be aliphatic, alicyclic, aromatic and heterocyclic. Preferred polycarboxylic acids contain 18 or fewer carbon atoms per carboxylic acid group, and suitable examples thereof include oxalic acid; sebacic acid; adipic acid; succinic acid; pimelic acid; suberic acid; glutaric acid; dimer and trimer acids of unsaturated fatty acids, such as dimer and trimer acids of linseed fatty acid; phthalic acid; isophthalic acid; terephthalic acid; trimellitic acid; trimesic acid; phenylenediacetic acid; chlorendic acid; hexahydrophthalic acid, particularly hexahydroorthophthalic acid (1,2-cyclohexanedicarboxylic acid); diphenic acid; naphthalic acid; polyacid terminal esters of dibasic acids and aliphatic polyols; polymers and copolymers of (meth)acrylic acid; and crotonic acid, but are not limited thereto.

[0105] Other suitable diepoxides that may be further mentioned include diepoxides of double unsaturated fatty acids C1-C 18 diepoxides of alkyl esters; butadiene diepoxide; polybutadiene diglycidyl ether; vinylcyclohexene diepoxide; and limonene diepoxide.

[0106] Examples of preferred polyepoxide compounds include bisphenol A epoxy resins such as DER™ 331, DER™ 332, DER™ 383, JER™ 828, and Epotec YD128; bisphenol F epoxy resins such as DER™ 354; bisphenol A / F epoxy resin blends such as DER™ 353; aliphatic glycidyl ethers such as DER™ 736; polypropylene glycol diglycidyl ethers such as DER™ 732; epoxy novolac resins such as DEN™ 438; brominated epoxy resins such as DER™ 542; castor oil triglycidyl ether such as ERISYS™ GE-35H; polyglycerol-3-polyglycidyl ether such as ERISYS™ GE-38; sorbitol glycidyl ether such as ERISYS™ GE-60; and bis(2,3-epoxypropyl) cyclohexane-1,2-dicarboxylate available as Lapox Arch-11. In particular, the selection of a solubilizer comprising or consisting of a bisphenol A epoxy resin is noted.

[0107] When the solubilizer of the second component of the composition is based on one or more epoxy resins, the present invention does not exclude that the solubilizer further comprises one or more cyclic compounds selected from the group consisting of oxetane, cyclic carbonate, cyclic anhydride, and lactone. The following cited disclosures may be useful in disclosing suitable cyclic carbonate functional compounds: U.S. Patent No. 3,535,342, U.S. Patent No. 4,835,289, U.S. Patent No. 4,892,954, British Patent Application Publication No. 1,485,925, and European Patent Application Publication No. 0119840. However, such additional cyclic compounds preferably constitute less than 20% by weight, more preferably less than 10% by weight or less than 5% by weight, based on the total weight of the epoxide compound.

[0108] In another embodiment not intended to mutually exclude the above, the solubilizer of the second component is liquid at room temperature and contains at least one polymer selected from the group consisting of polyphosphazene; polymethylene sulfide; polyoxyalkylene glycol; and polyethyleneimine. Particular mention can be made of the selection of polyoxy(C2-C3)alkylene glycol having a weight average molecular weight of 350 to 10,000 g / mol, for example 500 to 5,000 g / mol.

[0109] ≪Additives and Auxiliary Components≫ The above compositions obtained in the present invention usually further contain auxiliaries and additives that can impart improved properties to these compositions. For example, the auxiliaries and additives can impart one or more of improved elastic properties; improved elastic recovery; longer processable time; faster curing time; and low residual tack. Among such auxiliaries and additives, those that can be contained in one component (liquid) or both components (liquids) of a two-component (2K) composition, independently of each other, are plasticizers; stabilizers such as ultraviolet stabilizers; antioxidants; reinforcing agents; conductive fillers; non-conductive fillers; reactive diluents; drying agents; adhesion promoters; bactericides; flame retardants; rheology aids; coloring pigments or color pastes; and / or, optionally further, a small amount of non-reactive diluent.

[0110] Such auxiliaries and additives can be used in the desired combinations and ratios, provided that they do not adversely affect the properties and essential characteristics of the composition. Although there may be exceptions, these auxiliaries and additives should not exceed 50% by weight of the total composition as a whole, and preferably should not exceed 20% by weight of the composition.

[0111] To be complete, it should be noted that auxiliary materials and additives containing reactive groups are generally incorporated into the appropriate component (liquid) of a two-component (2K) composition to ensure its storage stability. Non-reactive materials can be incorporated into either one or both of the two components.

[0112] For the purposes of the present invention, a "plasticizer" is a substance that reduces the viscosity of a composition and promotes its processability. In the present specification, the plasticizer may constitute up to 10 wt% or up to 5 wt% based on the total weight of the composition, and preferably is polydimethylsiloxane (PDMS); diurethane; monofunctional, linear or branched C4-C 16 ethers of alcohols, such as Cetiol OE (available from Cognis Deutschland GmbH, Düsseldorf), etc.; 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 fatty acids having an OH group or epoxidized; glycolic acid esters; benzoic acid esters; phosphoric acid esters; sulfonic acid esters; trimellitic acid esters; epoxidized plasticizers; polyether plasticizers, such as end-capped polyethylene or polypropylene glycols, etc.; polystyrene; hydrocarbon plasticizers; chlorinated paraffins; and mixtures thereof. In principle, phthalic acid esters can be used as plasticizers, but it should be noted that these are not preferred because of their potential toxicity. The plasticizer preferably comprises or consists of one or more polydimethylsiloxanes (PDMS).

[0113] For the purposes of the present invention, a "stabilizer" should be understood as an antioxidant, a UV stabilizer or a hydrolysis stabilizer. In the present specification, the stabilizer may constitute up to 10 wt% or up to 5 wt% in total based on the total weight of the composition. Standard commercially available examples of stabilizers suitable for use herein include sterically hindered phenols; thioethers; benzotriazoles; benzophenones; benzoates; cyanoacrylates; acrylates; amines of the hindered amine light stabilizer (HALS) type; phosphorus; sulfur; and mixtures thereof.

[0114] Those compositions of the present invention may optionally include reinforcing rubber in the form of core-shell particles dispersed in an epoxy resin matrix. The term "core-shell rubber" or CSR is used according to its standard meaning in the art to denote a rubber particle core formed of a polymer containing an elastic or rubbery polymer as a main component, and a shell layer formed of a polymer graft-polymerized on the core. The shell layer partially or completely covers the surface of the rubber particle core in the graft polymerization process. By weight, the core must constitute at least 50% by weight of the core-shell rubber particles.

[0115] The polymer material of the core has a glass transition temperature (Tg) of 0 °C or lower, preferably -20 °C or lower, more preferably -40 °C or lower, and even more preferably -60 °C or lower. The polymer of the shell is a non-elastic, thermoplastic or thermosetting polymer having a glass transition temperature (Tg) higher than room temperature, preferably higher than 30 °C, more preferably higher than 50 °C.

[0116] Without intending to limit the present invention, the core may be composed of a diene homopolymer, such as a homopolymer of butadiene or isoprene; a diene copolymer, such as a copolymer of butadiene or isoprene and one or more ethylenically unsaturated monomers, such as a vinyl aromatic monomer, (meth)acrylonitrile or (meth)acrylate; a polymer based on a (meth)acrylate monomer, such as polybutyl acrylate; and a polysiloxane elastomer, such as polydimethylsiloxane and crosslinked polydimethylsiloxane.

[0117] Similarly, without intending to limit the present invention, the shell can be composed of a polymer or copolymer of one or more monomers selected from (meth)acrylates, such as methyl methacrylate; vinyl aromatic monomers, such as styrene; vinyl cyanides, such as acrylonitrile; unsaturated acids and anhydrides, such as acrylic acid; and (meth)acrylamides. The polymer or copolymer used in the shell can have ionically crosslinked acid groups through the formation of metal carboxylates, particularly salts of divalent metal cations. The shell polymer or copolymer can also be covalently crosslinked by monomers having two or more double bonds per molecule.

[0118] The core-shell rubber particles included preferably have an average particle size (d50) of 10 nm to 300 nm, such as 50 nm to 250 nm. The particle size refers to the diameter or the maximum dimension of the particles in the particle size distribution and is measured by dynamic light scattering. To be complete, this application does not exclude the presence of two or more core-shell rubber (CRS) particles having different particle size distributions in the composition in order to provide a balance of important properties of the resulting cured product, such as shear strength, peel strength, and resin fracture toughness.

[0119] The core-shell rubber can be selected from commercially available products, examples of which include Paraloid EXL2650A, EXL2655, and EXL2691A available from The Dow Chemical Company; Clearstrength® XT100 available from Arkema, Kane Ace® MX series, particularly MX120, MX125, MX130, MX136, MX551, MX553 available from Kaneka Corporation; and METABLEN SX-006 available from Mitsubishi Rayon.

[0120] The core-shell rubber particles are preferably included in the composition in an amount of 0 to 15% by weight, such as up to 10% by weight, based on the total weight of the composition.

[0121] As described above, the composition of the present invention can further include a conductive filler. There is no particular intention to limit the shape of the particles generally used as the conductive filler. Needle-shaped, spherical, elliptical, cylindrical, bead-shaped, cubic or platelet-shaped particles can be used alone or in combination. Furthermore, it is considered that aggregates of multiple types of particles can be used. Similarly, there is no particular intention to limit the particle size used as the conductive filler. However, such conductive fillers conventionally have an average volume particle size of 1 to 500 μm, for example 1 to 200 μm, measured by the laser diffraction / scattering method.

[0122] Exemplary conductive fillers include, but are not limited to, silver, copper, gold, palladium, platinum, nickel, gold-coated or silver-coated nickel, carbon black, carbon fiber, graphite, aluminum, indium tin oxide, silver-coated copper, silver-coated aluminum, metal-coated glass spheres, metal-coated fillers, metal-coated polymers, silver-coated fibers, silver-coated spheres, antimony-doped tin oxide, conductive nanospheres, nano silver, nano aluminum, nano copper, nano nickel, carbon nanotubes, and mixtures thereof. It is preferable to use particulate silver and / or carbon black as the conductive filler.

[0123] In certain important embodiments, the conductive filler may be included in the composition in an amount of 0 to 10% by weight, for example, up to 5% by weight, based on the total weight of the composition.

[0124] The presence of non-conductive fillers in the composition is not excluded. Apart from suppressing the viscosity of the composition, such fillers can be added as desired in order to reduce the coefficient of thermal expansion of the adhesive. Generally, there is no special intention to limit the shape of the particles used as non-conductive fillers, and acicular, spherical, elliptical, cylindrical, bead-shaped, cubic or platelet-shaped particles can be used alone or in combination. Furthermore, it is considered that aggregates of multiple types of particles can be used. Similarly, there is no special intention to limit the particle size used as the non-conductive filler. However, such non-conductive fillers conventionally have an average volume particle size of 0.1 to 1500 μm, for example 1 to 1000 μm or 1 to 500 μm, as measured by the laser diffraction / scattering method.

[0125] Exemplary non-conductive fillers include, but are not limited to, chalk, lime powder, precipitated and / or pyrogenic silica, zeolite, bentonite, magnesium carbonate, diatomaceous earth, alumina, clay, talc, sand, quartz, flint, mica, glass powder and other crushed mineral substances. Short fibers such as glass fibers, glass filaments, polyacrylonitrile, carbon fibers, polyethylene fibers, etc. can also be added.

[0126] Pyrogenic and / or precipitated silica preferably has a BET specific surface area of 10 to 90 m 2 / g. When they are used, no further increase in the viscosity of the composition of the present invention is caused, and it contributes to the strengthening of the cured composition.

[0127] Similarly, it is conceivable to use pyrogenic and / or precipitated silica having a higher, preferably 100 to 250 m 2 / g BET specific surface area as a filler. Due to the larger BET specific surface area, the effect of strengthening the cured composition with a smaller weight ratio of silica is achieved.

[0128] Suitable as the non-conductive filler are hollow spheres having a mineral shell or a plastic shell. These may be, for example, hollow glass spheres commercially available under the trade name Glass Bubbles (registered trademark). Plastic-based hollow spheres such as Expancel (registered trademark) and Dualite (registered trademark) may also be used, as described in European Patent No. 0520426. They are composed of inorganic or organic substances and have a diameter of 1 mm or less, preferably 500 μm or less, and preferably 100 μm to 200 μm, respectively.

[0129] Non-conductive fillers that impart thixotropy to the composition can be suitable for many applications. Such fillers are also described as rheology aids, such as hydrogenated castor oil, fatty acid amides, or swelling plastics such as PVC.

[0130] The total amount of both the conductive and non-conductive fillers present in the composition of the present invention is preferably 0 to 20% by weight, more preferably 0 to 10% by weight, based on the total weight of the composition. The desired viscosity of the curable composition is usually determined by the total amount of filler added and the curable composition should have a viscosity of 3000 to 150,000, preferably 40,000 to 80,000 mPas, or even 50,000 to 60,000 mPas in order to be easily extrudable from a suitable dispensing device such as a tube.

[0131] In order to further extend the shelf life, it is often recommended to further stabilize the composition of the present invention against moisture penetration using a desiccant. Also, there is sometimes a need to lower the viscosity of the adhesive composition of the present invention for specific applications by using a reactive diluent. The total amount of reactive diluent present is usually 0 to 15% by weight, for example, 0 to 5% by weight, based on the total weight of the composition.

[0132] The presence of solvents and non-reactive diluents in the composition of the present invention is also not excluded when their viscosities can be effectively suppressed thereby. For example, for illustrative purposes only, 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 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; diisopropylnaphthalene; petroleum fractions such as Solvesso® products (available from Exxon); alkylphenols such as tert-butylphenol, nonylphenol, dodecylphenol, and 8,11,14-pentadecatrienylphenol; styrenated phenol; bisphenol; aromatic hydrocarbon resins, particularly those containing phenolic groups such as ethoxylated or propoxylated phenols; adipates; sebacates; phthalates; benzoates; organic phosphates or sulfonic acid esters; and sulfonamides.

[0133] Separately from the above, the non-reactive diluent preferably constitutes less than 10% by weight, particularly less than 5% by weight or less than 2% by weight, in total, based on the total weight of the composition.

[0134] <Exemplary Embodiments of Two-Component (2K) Compositions> In an exemplary embodiment of the present invention, the two-component (2K) adhesive composition comprises Based on the weight of the first component, 40 to 75% by weight, preferably 47 to 68% by weight of a (meth)acrylate monomer, wherein the (meth)acrylate monomer comprises at least one C1-C6 alkyl ester of (meth)acrylic acid, 6 to 16% by weight, preferably 10 to 13% by weight of a copolymerizable acid, wherein the copolymerizable acid is selected from the group consisting of methacrylic acid, acrylic acid, itaconic acid, maleic acid, aconitic acid, crotonic acid, fumaric acid, and mixtures thereof, and 4 to 23% by weight, preferably 5 to 20% by weight of an electrolyte, wherein the electrolyte is selected from the group consisting of 1-ethyl-3-methylimidazolium methanesulfonate, 1-ethyl-3-methylimidazolium methyl sulfate, and mixtures thereof, A first component comprising Based on the weight of the second component, 55 to 70% by weight, preferably 61 to 65% by weight or 30 to 55% by weight, preferably 30 to 45% by weight of at least one free radical initiator that decomposes under the action of heat to provide free radicals, or consisting of 0.03 to 1% by weight, preferably 0.05 to 0.3% by weight of at least one compound that is a salt or complex of a transition metal selected from the group consisting of Fe, Co, V, Mn, and Cu, and 28 to 40% by weight, preferably 35 to 38% by weight of a solubilizer A second component comprising Comprising The first component and / or the second component further comprises conductive particles selected from the group consisting of carbon black, silver, and mixtures thereof.

[0135] In this embodiment, the first curing agent is preferably a peroxide or hydroperoxide compound selected from the group consisting of tert-butyl peroxide, tert-butyl perbenzoate, cumene hydroperoxide, tert-butyl peroxybenzoate, diacetyl peroxide, benzoyl peroxide, tert-butyl peracetate, lauryl peroxide, and mixtures thereof. In particular, the selection of benzoyl peroxide is noted. Apart from, or in addition to, this reference to the selection of the first curing agent, the second curing agent preferably comprises, or consists of, at least one iron-based compound selected from the group consisting of ferrocene, iron(II) acetylacetonate, ammonium iron (III) hexakis (cyano-C) ferrate. In particular, the selection of ferrocene is noted.

[0136] <Method and Application> To form a defined two-component (2K) curable composition, the reactive components are brought together and mixed in a manner that induces their curing. The reactive compounds need to be mixed under sufficient shear force to produce a homogeneous mixture. This is considered achievable without special conditions or special equipment. However, suitable mixing devices can include magnetic stir bar devices; wire whisks; augers; batch mixers; planetary mixers; C.W. Brabender or Banburry® type mixers; and high-shear mixers such as blade-type mixers and rotary impellers.

[0137] For small-scale applications where a volume of less than 2 liters is typically used, a preferred packaging for a two-component (2K) composition is a side-by-side double cartridge or a coaxial cartridge where two tubular chambers (usually of equal volume) are arranged side by side or inside each other and sealed with pistons. By driving these pistons, the components can be advantageously extruded from the cartridge using a closely attached static or dynamic mixer. For larger-scale applications, the two components of the composition can be advantageously stored in drums or pails. In this case, the two components are extruded using a hydraulic press, in particular via a follower plate, and supplied to a mixing device through a pipeline, thereby ensuring a fine and highly homogeneous mixing of the two components. In any case, for any package, it is important to seal the components in an airtight and moisture-proof seal so that both components can be stored for a long period, ideally for more than 12 months.

[0138] Non-limiting examples of two-component dispensing devices and methods suitable for the present invention include those described in U.S. Patent No. 6,129,244 and U.S. Patent No. 8,313,006.

[0139] Depending on the desired properties of the cured composition, the two components are conventionally mixed at a volume ratio of component A: component B of 20:1 to 1:10, for example, 10:1 to 1:10, for example 5:1 to 1:5, or for example 2:1 to 1:2 or 1.5:1 to 1:1.5. The latter range includes a volume ratio of component A: component B of 1:1, which in itself presents one preferred embodiment of the present invention. Another preferred embodiment is a volume ratio of component A: component B of 10:1. In some embodiments, the volume ratio of component A: component B may be 1:12. In one highly preferred embodiment, the volume ratio of component A: component B is from 12:1 to 6.5:1.

[0140] When applicable, the two-component (2K) curable composition needs to be prepared extensively so that the initial viscosity (the viscosity measured immediately after mixing, for example, within up to 2 minutes after mixing) is less than 200,000 mPa·s at 25°C, for example, less than 100,000 mPa·s. Apart from or in addition to the above viscosity characteristics, the two-component (2K) composition must be prepared so that there are no air bubbles (foams) during mixing and subsequent curing.

[0141] According to the broadest method aspect of the present invention, the above composition is applied to a material layer and then cured in place. Before applying the composition, it is often recommended to pretreat the relevant surface to remove foreign substances therefrom. This step, when applicable, facilitates the subsequent adhesion of the composition. Such treatments are known in the art and include, for example, etching treatment with an acid suitable for the substrate and, optionally, an oxidizing agent; ultrasonic treatment; plasma treatments such as 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 carbon tetrachloride or trichloroethylene; and one or more of rinsing with water, preferably deionized water or demineralized water, which can be carried out in a one-step or multi-step method. When using an aqueous alkaline degreasing bath, it is desirable to remove the degreasing agent remaining on the surface by rinsing the substrate surface with deionized water or degreasing water.

[0142] Next, the composition is preferably applied to the surface of the pretreated substrate by conventional coating methods such as brushing; roll coating using a four-roll coating device when the composition is solvent-free, or a two-roll coating device for a solvent-containing composition; doctor blade coating; printing methods; and spraying methods such as air spray, air-assisted spray, airless spray, and high-volume low-pressure spray, although not limited thereto.

[0143] As described above, the present invention provides an adhesive structure including a first material layer having a conductive surface and a second material layer having a conductive surface, wherein a cured and peelable two-component (2K) adhesive composition defined in the foregoing and the appended claims is disposed between the first and second material layers. To manufacture such a structure, the adhesive composition is applied to the inner surface of at least one of the first material layer and / or the second material layer, and then the two layers are brought into contact such that the curable and peelable adhesive composition of the present invention is interposed between the two layers.

[0144] The composition is preferably applied to the surface with a wet film thickness of 10 to 500 μm. Applying to a thinner layer within this range is more economical and reduces the possibility of harmful thick cured regions. However, in order to avoid the formation of a discontinuous cured film, precise control must be performed when applying a thinner coating or layer.

[0145] Curing of the applied composition of the present invention typically occurs in the temperature range of 40°C to 200°C, preferably 50°C to 175°C, particularly 75°C to 175°C. The appropriate temperature depends on the specific compounds present and the desired curing rate and can be determined in individual cases by those skilled in the art using simple preliminary tests as necessary. Naturally, curing at a lower temperature within the aforementioned range is advantageous because it does not require substantially heating or cooling the mixture from the normal ambient temperature. However, where applicable, the temperature of the mixture formed from each component of the two-component (2K) composition can be raised to a temperature above the mixing temperature and / or the application temperature using conventional means such as microwave induction.

[0146] The present invention will be described with reference to the following accompanying drawings.

[0147] As shown in Figure 1a attached to this specification, an adhesive structure is provided in which a layer of a curable adhesive (10) is disposed between two conductive substrates (11). A layer of a non-conductive material (12) can be disposed on the conductive substrate (11) to form a more complex adhesive structure as shown in Figure 1b. Each layer of the conductive substrate (11) is in electrical contact with a power source (13) which can be a battery or a DC source driven by AC. The positive and negative terminals of the power source (13) are shown in one fixed position, but those skilled in the art will of course recognize that the polarity of the system can be reversed.

[0148] The two conductive substrates (11) are shown in the form of layers that can be composed of, inter alia, a metal film; a metal sheet; a metal mesh or grid; deposited metal particles; a resin material made conductive by conductive elements disposed therein; or a conductive oxide layer. Exemplary conductive elements can include silver filaments, single-walled carbon nanotubes, and multi-walled carbon nanotubes. Exemplary conductive oxides can include doped indium oxide, such as indium tin oxide (ITO); doped zinc oxide; antimony tin oxide; cadmium stannate; and zinc stannate. Apart from the selection of the conductive material, those skilled in the art will recognize that when the conductive substrate (11) is in the form of a grid or mesh that limits contact with the layer of the curable adhesive (10), the effectiveness of the peeling operation may be reduced.

[0149] When a voltage is applied between each conductive substrate (11), a current is supplied to the adhesive composition (10) disposed therebetween. This induces an electrochemical reaction at the interface between the substrate (11) and the adhesive composition. This electrochemical reaction is understood to be oxidative at the positively charged or anodic interface and reductive at the negatively charged or cathodic interface. The reaction is thought to weaken the adhesive bond between the substrates and allow the composition that can be peeled from the substrate to be easily removed.

[0150] As depicted in FIGS. 2a and 2b, delamination occurs at the positive interface, which is the interface between the conductive surface (11) in electrical contact with the adhesive composition (10) and the positive electrode. By reversing the direction of the current before separating the substrates, the adhesive bond can be weakened at both substrate interfaces.

[0151] However, it should be noted that the composition of the adhesive layer (10) can be adjusted so that delamination occurs at either the positive or negative interface, or simultaneously from both. For some embodiments, the voltage applied to both surfaces to form the anode and cathode interfaces causes delamination to occur simultaneously at both the anode and cathode adhesive / substrate interfaces. In another embodiment, if the composition does not respond to direct current at both interfaces, reverse polarity can be used to delaminate both substrate / adhesive interfaces simultaneously. The current can be applied in any suitable waveform, provided that the total time allowed for delamination to occur at each polarity is sufficient. Sinusoidal, rectangular, and triangular waveforms may be appropriate in this regard and can be applied from a controlled voltage or current source.

[0152] Without intending to limit the present invention, it is believed that the delamination operation can be effectively performed when at least one, preferably both, of the following conditions are caused: a) an applied voltage of 0.5 to 100 V; and b) a voltage applied for a period of 1 second to 60 minutes. If the delamination of the conductive substrate from the cured adhesive is facilitated by the application of a force exerted, for example, by a weight or a spring, the potential requires only an application on the order of a few seconds. In some embodiments, a potential of 5 V for 10 minutes is sufficient to have a delamination effect, while in some other embodiments, a potential of 3.5 V for 30 minutes is sufficient.

[0153] After delamination, it is desirable that the adhesive composition be present only on the first substrate or the second substrate, which means that one of the substrates is substantially free of the adhesive.

[0154] 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

[0155] In the examples, the following materials were used. Aerosil 200: hydrophilic fumed silica, available from Evonik Clearstrength® XT100: core-shell toughener (methyl methacrylate-butadiene-styrene, MBS), available from Arkema 1-Ethyl-3-methylimidazolium methanesulfonate: available from TCI America Ferrocene: bis(η5-cyclopentadienyl)iron, available from Sigma-Aldrich DER 331: bisphenol A epoxy resin, available from Dow Chemical Benzoyl peroxide (75%): powder, available from Arkema.

[0156] Example 1 Components (A) and (B) of Composition 1 were prepared according to Table 1 below.

[0157] [Table 1]

[0158] Components (A, B) were placed in equal weights in separate compartments of a 50 g cartridge and both ends were sealed. Then, the cartridge was loaded into a cartridge gun and a mixing tip was attached to the front end. By applying a constant pressure to the trigger, the two components were pushed into the mixing tip to ensure sufficient mixing before applying to the described substrate.

[0159] The substrates were cut from copper (1 mm thick), aluminum (AA6016, 1.25 mm thick), and stainless steel (1.4301, 1.5 mm thick), each having the respective substrate thickness, into dimensions of 2.5 cm × 10 cm (1 inch × 4 inches) for tensile testing.

[0160] The tensile lap shear (TLS) test was conducted according to the test method described on page 5.

[0161] The applied two-component (2K) adhesive composition was cured in the overlapping area by applying a temperature of 100 °C for 30 minutes. Thereafter, the sample was stored in a climate chamber at 25 °C and 20% humidity.

[0162] For each substrate, before Note After the storage period and after applying a constant potential of 75 V to the entire adhesive layer for 1 hour, the tensile lap shear strength was examined. The results are shown in Table 2 below.

[0163]

Table 2

[0164] For the bonded stainless steel substrates, the lap shear strength (MPa) was examined under two conditions: a) applying a constant potential (75 V) to the entire overlapping adhesive area for 20 minutes; and b) applying different potentials to the entire overlapping adhesive area for a certain period (10 minutes). The results of these investigations are shown in Figures 3a and 3b attached to this specification.

[0165] For the bonded aluminum substrates, the lap shear strength (MPa) was examined under two conditions: a) applying a constant potential (75 V) to the entire overlapping adhesive area for 20 minutes; and b) applying different potentials to the entire overlapping adhesive area for a certain period (10 minutes). The results of these investigations are shown in Figures 4a and 4b attached to this specification.

[0166] Example 2 Components (A) and (B) of Composition 2 were prepared according to Table 3 below. Composition 2 was prepared and tested according to the method described in Example 1.

[0167]

Table 3

[0168] For each base material, the tensile lap shear strength was examined both after the previous storage period and after applying a constant potential of 75 V to the entire adhesive layer for 1 hour. The results are shown in Table 4 below.

[0169] [Table 4] Example 3

[0170] Components (A) and (B) of Composition 3 were prepared according to Table 5 below. Composition 3 was prepared and tested according to the method described in Example 1.

[0171] [Table 5]

[0172] For the base material, the tensile lap shear strength was investigated both after the above storage period and after applying a constant potential of 75 V to the entire adhesive layer for 1 hour. The results are shown in Table 6 below.

[0173] [Table 6]

[0174] Example 4 Components (A) and (B) of Composition 4 were prepared according to Table 7 below. Composition 4 was prepared and tested according to the method described in Example 1.

[0175] [Table 7]

[0176] For each base material, the tensile lap shear strength was investigated both after the above storage period and after applying a constant potential of 75 V to the entire adhesive layer for 1 hour. The results are shown in Table 8 below.

[0177] [Table 8]

[0178] Example 5 Components (A) and (B) of Composition 5 were prepared according to Table 9 below. Composition 5 was prepared and tested according to the method described in Example 1.

[0179] [Table 9]

[0180] For each substrate, the tensile lap shear strength was investigated both after the above storage period and after applying a constant potential of 75 V to the entire adhesive layer for 1 hour. The results are shown in Table 10 below.

[0181] [Table 10]

[0182] Considering the above description and examples, it will be apparent to those skilled in the art that equivalent changes can be made without departing from the scope of the claims.

[0183] Example 6 A stability test was carried out on the composition of Example 1. In this test, normal lap shear specimens were prepared and cured at 100 °C for 30 minutes. Aluminum and steel substrates were used. Subsequently, the specimens were stored in a climate chamber at 25 °C and 20% humidity. Lap shear was measured after 1 day, 7 days, 14 days, 28 days, 60 days, and 90 days. The results are shown in Tables 11 and 12 below.

[0184] [Table 11]

[0185] [Table 12]

[0186] The stability results are shown in FIGS. 5a and 5b. FIG. 5a shows the adhesion and peeling effect on aluminum, and FIG. 5b shows the adhesion and peeling effect on stainless steel. The test results indicate that the composition of the present invention has good initial adhesion and does not lose it over time. Furthermore, the composition of the present invention has a good initial peeling effect and maintains it over time.

[0187] Example 7 Components (A) and (B) of Compositions 6a and 6b were prepared according to Table 13 below. Compositions 6a and 6b were prepared and tested according to the method described in Example 1.

[0188] [Table 13]

[0189] For the substrate, the tensile lap shear strength was investigated both after the above storage period and after applying a constant potential of 75 V to the entire adhesive layer for 20 minutes. The results are shown in Table 14 below. The test results are shown in FIG. 6.

[0190] [Table 14]

[0191] Example 8 Composition 7 was prepared according to Table 15 below. Note that methacrylic acid was excluded from the composition. Otherwise, the composition conforms to the present invention.

[0192] [Table 15]

[0193] Composition 7 does not cure and the electrolyte separates from the composition.

[0194] Example 9 Compositions 8a, 8b and 8c were prepared according to Table 16 below.

[0195]

Table 16

[0196] For the base material, the tensile lap shear strength was investigated both after the above storage period and after applying a constant potential of 75 V to the entire adhesive layer for 20 minutes. The results are shown in Table 17 below in this specification, and the test results are further shown in Figure 7.

[0197]

Table 17

[0198] Example 10 Compositions 9a, 9b, and 9c were prepared according to Table 18 below.

[0199]

Table 18

[0200] For the base material, the tensile lap shear strength was investigated both after the above storage period and after applying a constant potential of 75 V to the entire adhesive layer. The results are shown in Table 19 below.

[0201]

Table 19

[0202] Example 11 Various electrolyte concentrations were tested. Compositions 10a, 10b, 10c, 10d, and 10e were prepared according to Table 20 below.

[0203]

Table 20

[0204] For the base material, the tensile lap shear strength was investigated both after the above storage period and after applying a constant potential of 75 V to the entire adhesive layer for 75Both were investigated after applying a constant potential of V for 20 minutes. The results are shown in Table 21 below. The test results are shown in Figure 8.

[0205]

Table 21

[0206] Example 12 Improvement of T-peeling due to various reinforcing agents and concentrations of core-shell particles, as well as the effects on the aging test (90% Rh), stability, and LSS values are shown. Compositions 11a, 11b, 11c, 11d, and 11e were prepared according to Table 22 below.

[0207]

Table 22

[0208] Regarding the substrate, the tensile lap shear strength was investigated both after the above storage period and for the entire adhesive layer 75 Both were investigated after applying a constant potential of V for 20 minutes. The results are shown in Table 23 below. This is also shown in Fig. 9.

[0209] Table 24 below shows Wedge impact test (ISO 11343) and peel strength (STM 710) the results of the test Yes.

[0210]

Table 24

Claims

1. (Meth)acrylate monomer, copolymerizable acid, and electrolyte a first component containing the same, a first curing agent for the monomer of the first component, a second curing agent for the monomer of the first component, and solubilizer a second component containing the same containing, the first curing agent is a peroxide curing agent selected from the group consisting of tert-butyl peroxide, tert-butyl perbenzoate, cumene hydroperoxide, tert-butyl peroxybenzoate, diacetyl peroxide, benzoyl peroxide, tert-butyl peracetate, lauryl peroxide and mixtures thereof; the second curing agent is a metal compound selected from salts and complexes of iron, copper, cobalt, vanadium and manganese, and is present in an amount of 0.01 to 1% by weight of the total weight of the second component; the first component and / or the second component further contains conductive particles selected from the group consisting of carbon black, silver, and mixtures thereof, a curable and peelable two-component adhesive composition.

2. The (meth)acrylate monomer is methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl-(meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, phenyl (meth)acrylate, tolyl (meth)acrylate, benzyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, stearyl (meth)acrylate, glycidyl (meth)acrylate, isobornyl (meth)acrylate, 2-aminoethyl (meth)acrylate, γ-(meth)acryloyloxypropyltrimethoxysilane, (meth)acrylic acid-ethylene oxide adduct, trifluoromethylmethyl (meth)acrylate, 2-trifluoromethylethyl (meth)acrylate, 2-perfluoroethylethyl (meth)acrylate, 2-perfluoroethyl-2-perfluorobutylethyl (meth)acrylate, 2-perfluoroethyl (meth)acrylate, perfluoromethyl (meth)acrylate, dipentafluoroethylmethyl (meth)acrylate, 2-perfluoromethyl-2-perfluoroethylmethyl (meth)acrylate, 2-perfluorohexylethyl (meth)acrylate, 2-perfluorodecylethyl (meth)acrylate, 2-perfluorohexadecylethyl (meth)acrylate, ethoxylated trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, dipentaerythritol monohydroxypentaacrylate, pentaerythritol triacrylate, ethoxylated trimethylolpropane triacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, pentaerythritol tetraacrylate, 1,The curable and peelable two-component adhesive composition according to claim 1, which is selected from the group consisting of 2-butylene glycol diacrylate, trimethylolpropane ethoxylate tri(meth)acrylate, glyceryl propoxylate tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, tripropylene glycol di(meth)acrylate, neopentyl glycol propoxylate di(meth)acrylate, 1,4-butanediol di(meth)acrylate, polyethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, and mixtures thereof.

3. The curable and peelable two-component adhesive composition according to claim 1 or 2, wherein the (meth)acrylate monomer component is present in an amount of 20 to 80% by weight of the total weight of the first component.

4. The curable and peelable two-component adhesive composition according to any one of claims 1 to 3, wherein the copolymerizable acid is selected from the group consisting of methacrylic acid, acrylic acid, itaconic acid, maleic acid, aconitic acid, crotonic acid, fumaric acid, and mixtures thereof.

5. The curable and peelable two-component adhesive composition according to any one of claims 1 to 4, wherein the copolymerizable acid is present in an amount of 0.25 to 20% by weight of the total weight of the first component.

6. The electrolyte is 1-ethyl-3-methylimidazolium methanesulfonate, 1-ethyl-3-methylimidazolium methylsulfate, 1-hexyl-3-methylimidazolium 2-(2-fluoroanilino)-pyridinate, 1-hexyl-3-methylimidazolium imide, 1-butyl-1-methyl-pyrrolidinium 2-(2-fluoroanilino)-pyridinate, 1-butyl-1-methyl-pyrrolidinium imide, trihexyl(tetradecyl)phosphonium 2-(2-fluoroanilino)-pyridinate, cyclohexyltrimethylammonium bis(trifluoromethylsulfonyl)imide, di(2-hydroxyethyl)ammonium trifluoroacetate, N,N-dimethyl(2-hydroxyethyl)ammonium octanoate, methyltrioctylammonium bis(trifluoromethylsulfonyl)imide, N-ethyl-N,N,N,N-tetramethylguanidinium trifluoromethanesulfonate, guanidinium trifluoromethanesulfonate, 1-butyl-4-methylpyridinium bromide, 1-butyl-3-methylpyridinium tetrafluoroborate, 1-butyl-3-hydroxymethylpyridinium ethylsulfate, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-butyl-methylpyrrolidinium tris(pentafluoroethyl)trifluorophosphate, 3-methylimidazolium ethylsulfate, 1-ethyl-3-methylimidazolium chloride, 1-ethyl-3-ethyl-methylimidazolium bromide, 1-butyl-3-methylimidazolium chloride, 1-hexyl-3-methylimidazolium chloride, 1-octyl-3-methylimidazolium chloride, 1-methyl-3-octylimidazolium chloride, 1-propyl-3-methylimidazolium iodide, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazolium hexafluorophosphate, 1-butyl-2,3-dimethylimidazolium tetrafluoroborate, 1-butyl-2,A curable and peelable two-component adhesive composition according to any one of claims 1 to 5, selected from the group consisting of 3-dimethylimidazolium hexafluorophosphate, 1-butylimidazole, 1-methylimidazolium tetrafluoroborate, tetrabutylphosphonium tris(pentafluoroethyl) trifluorophosphate, trihexyl(tetradecyl)phosphonium tetrafluoroborate, and mixtures thereof.,

7. The curable and peelable two-component adhesive composition according to any one of claims 1 to 6, wherein the electrolyte is present in an amount of 2.5 to 25% by weight of the total weight of the first component.

8. The curable and peelable two-component adhesive composition according to any one of claims 1 to 7, wherein the first curing agent is benzoyl peroxide.

9. The curable and peelable two-component adhesive composition according to any one of claims 1 to 8, wherein the first curing agent is present in an amount of 25 to 75% by weight of the total weight of the second component.

10. The curable and peelable two-component adhesive composition according to any one of claims 1 to 9, wherein the second curing agent is an iron-based compound selected from the group consisting of ferrocene, iron(II) acetylacetonate, ammonium iron(III) hexakis(cyano-C)ferrate, and mixtures thereof.

11. The curable and peelable two-component adhesive composition according to any one of claims 1 to 10, wherein the second curing agent is present in an amount of 0.05 to 0.3% by weight of the total weight of the second component.

12. The curable and peelable two-component adhesive composition according to any one of claims 1 to 11, wherein the solubilizer is polyethylene glycol or an epoxy resin selected from the group consisting of alicyclic epoxides, epoxy novolac resins, bisphenol A-epoxy resins, bisphenol-F-epoxy resins, bisphenol-A epichlorohydrin-based epoxy resins, alkyl epoxides, limonene dioxide, polyepoxides, and mixtures thereof.

13. The curable and peelable two-component adhesive composition according to any one of claims 1 to 12, wherein the solubilizer is present in an amount of 20 to 45% by weight of the total weight of the second component.

14. A first material layer having a conductive surface, and A second material layer having a conductive surface An adhesive structure comprising: The peelable two-component adhesive composition according to any one of claims 1 to 13, which is cured, is disposed between the first material layer and the second material layer.

15. i) A step of applying a voltage to the entire surface of both sides to form an anode interface and a cathode interface, and ii) A step of peeling the both surfaces A method for peeling the adhesive structure according to claim 14, comprising:

16. The method according to claim 15, wherein the voltage applied in step i) is 0.5 to 100 V, and the voltage is applied for 1 second to 60 minutes.

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