Double Curable Epoxy Adhesive Composition and cured product thereof

Abstract

The present invention relates to a dual-curing epoxy adhesive composition, and specifically, to provide a cured product having excellent adhesive strength and water resistance by preparing a dual-curing epoxy adhesive composition comprising a base epoxy, an epoxy compound containing a cyanate group, a photocuring agent, and a thermosetting agent, and curing the same.

Description

Technology Field

[0001] The present invention relates to a dual-curing epoxy adhesive composition and a cured product thereof, and more specifically, to a dual-curing epoxy adhesive composition having excellent adhesive strength and adhesion and high reliability, and a cured product thereof. Background Technology

[0002] Adhesives used in the assembly of conventional camera modules require low-temperature curing properties to avoid thermal damage caused by high-temperature processing of image sensors and the like. Additionally, fast-curable properties are simultaneously required to improve production efficiency. In this regard, photo-curing or thermal-curing adhesives are widely used as low-temperature fast-curing adhesives.

[0003] However, while photocurable adhesives allow for rapid curing, they have disadvantages such as causing curing deformation due to shrinkage or being unsuitable for bonding areas not exposed to light. Although thermocurable adhesives can be low-temperature, fast-curing adhesives, the components to be bonded must be secured with jigs or devices to maintain the bonding position during application. Furthermore, viscosity decreases with increasing temperature, leading to problems such as sagging just before curing or leakage to unintended areas, so they were not always satisfactory.

[0004] To solve the above problems, a dual-curing adhesive of the type that performs temporary fixation by irradiation with light (e.g., ultraviolet, visible light) and main curing by heat has recently been proposed. By using the above dual-curing adhesive, there is an advantage of being able to perform uniform main curing without additional devices.

[0005] However, the aforementioned dual-curing adhesive has a problem in that its fluidity decreases sharply as its modulus increases after UV curing. Since this decrease in fluidity may lead to an additional problem of reduced curing degree during thermal curing, there is a need for research on a dual-bond adhesive capable of overcoming this issue as well. Prior art literature

[0006] Republic of Korea Published Patent Application No. 10-2021-0052343 A (May 10, 2021) The problem to be solved

[0007] The objective of the present invention is to provide a dual-curing epoxy adhesive composition and a cured product thereof that are capable of sufficient curing, have excellent adhesive strength, adhesion, and water resistance, and possess high reliability.

[0008] Specifically, the invention provides a dual-curing epoxy adhesive composition and a cured product thereof that can be used as a low-temperature fast-curing adhesive, maintains its shape without flowing due to fluidity after photocuring, and can achieve a high degree of curing and adhesion through heat curing. means of solving the problem

[0009] To solve the above-mentioned problems, the present invention provides a dual-curing epoxy adhesive composition comprising: a base epoxy resin and an epoxy mixed resin containing an epoxy compound represented by the following chemical formula 1; a photocuring agent; and a thermosetting agent.

[0010] [Chemical Formula 1]

[0011]

[0012] In Chemical Formula 1, A is hydrocarbylene or heterohydrocarbylene, and the hydrocarbylene or heterohydrocarbylene is C1-C 20 Alkyl, -N=C=O, -OC≡N, C6-C 12 Aryl and C1-C 10 It may be further substituted with one or more substituents selected from the alkoxy group.

[0013] According to one aspect of the present invention, in the above formula 1, A is C1-C 20 Alkylene, C6-C 20 Arrylene, C6-C 20 Heteroarylene, C3-C 20 Cycloalkylene or C3-C 20 It may include heterocycloalkylene.

[0014] According to one embodiment of the present invention, the epoxy compound may comprise one or more selected from epoxy compounds represented by the following chemical formulas 2 to 4.

[0015] [Chemical Formula 2]

[0016]

[0017] [Chemical Formula 3]

[0018]

[0019] [Chemical Formula 4]

[0020]

[0021] In the above chemical formulas 2 to 4,

[0022] D1 is a single bond or C1-C 10 It is an alkylene,

[0023] Z is -(CR5R6) n - and, R5 and R6 are independently hydrogen, -N=C=O, -OC≡N, C1-C 10 Alkyl and C6-C 12 It is an aryl, where n is an integer from 0 to 3, and R1 to R4 are independent of each other, -N=C=O, -OC≡N, C1-C 10 alkyl or C6-C 12 It is an aryl, and o, p, and q are independent integers from 0 to 4, and r can be an integer from 0 to 4.

[0024] According to one aspect of the present invention, in the formulas 2 to 4, D1 is a single bond or a C1-C5 alkylene, and Z is -(CR5R6) n - and R5 and R6 are independently hydrogen, -N=C=O, -OC≡N, C1-C8 alkyl and C6-C8 aryl, n is an integer from 0 to 3, R1 to R4 are independently -N=C=O, -OC≡N, C1-C5 alkyl or C6-C8 aryl, o, p and q are independently integers from 0 to 4, and r may be an integer from 0 to 2.

[0025] According to one embodiment of the present invention, the epoxy compound may comprise that represented by the following chemical formula 5.

[0026] [Chemical Formula 5]

[0027]

[0028] In the above chemical formula 5, D1 may be a single bond, a C1-C5 straight-chain alkylene, or a C1-C5 branched alkylene.

[0029] According to one embodiment of the present invention, the epoxy mixed resin may comprise 50 to 400 parts by weight of the epoxy compound of Formula 1 with respect to 100 parts by weight of the base epoxy resin.

[0030] According to one embodiment of the present invention, the base epoxy resin may comprise one or more mixtures selected from novolak-type epoxy resin, bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, bisphenol E-type epoxy resin, biphenyl-type epoxy resin, triphenylmethane-type epoxy resin, phenol-aralkyl-type epoxy resin, halogenated epoxy resin, alicyclic epoxy resin, rubber-modified epoxy resin, aliphatic polyglycidyl-type epoxy resin, glycidyl amine-type epoxy resin, polyglycol epoxy resin, and cardanol epoxy resin.

[0031] According to one embodiment of the present invention, the photocuring agent may comprise a polyfunctional acrylic compound.

[0032] According to one embodiment of the present invention, the thermosetting agent may include an amine-based compound.

[0033] According to one embodiment of the present invention, the dual-curing epoxy adhesive composition may further comprise a photoradical initiator.

[0034] According to one embodiment of the present invention, the dual-curing epoxy adhesive composition may comprise 1 to 200 parts by weight of a photocuring agent and 1 to 200 parts by weight of a thermocuring agent, based on 100 parts by weight of an epoxy mixed resin.

[0035] According to one embodiment of the present invention, the dual-curing epoxy adhesive composition may further include an inorganic filler.

[0036] According to one embodiment of the present invention, the inorganic filler may be one or more mixtures selected from fumed silica, diatomaceous earth, alumina, zinc oxide, iron oxide, magnesium oxide, tin oxide, titanium oxide, magnesium hydroxide, aluminum hydroxide, magnesium carbonate, barium sulfate, gypsum, calcium silicate, talc, glass beads, fused silica, quartz powder, sericite, talc clay, bentonite, aluminum nitride, silicon nitride, potassium titanate, zeolite, calcia, magnesia, and ferrite.

[0037] According to one embodiment of the present invention, a dual-curing epoxy adhesive composition may further include a stabilizer.

[0038] According to one embodiment of the present invention, a dual-curing epoxy adhesive composition may further comprise an adhesion promoter.

[0039] According to one aspect of the present invention, a cured product of the epoxy adhesive composition can be provided.

[0040] According to the present invention, light curing, heat curing, or dual curing combining these can be selected and performed depending on the usage environment or purpose, and through dual curing, improved adhesive strength can be achieved, so it can be used as a higher quality structural adhesive.

[0041] According to the present invention, the dual-curing epoxy adhesive composition comprises an epoxy compound represented by Formula 1, thereby having a superior degree of thermal curing compared to when the epoxy resin is used alone, and accordingly, can provide a cured product with excellent adhesion and reliability.

[0042] The cured product according to the present invention achieves a high Tg of 100°C or higher, can have excellent adhesion even after a high temperature and high humidity environment, has excellent storage stability, and in particular, has the advantage of a smooth adhesive interface.

[0043] The cured material according to the present invention can be usefully applied as a material for forming various optical members and optical devices, and is particularly expected to be usefully applied as an adhesive layer between constituent members, such as camera modules, that require high adhesive strength and water resistance per unit area. Effects of the invention

[0044] According to the present invention, light curing, heat curing, or dual curing combining these can be selected and performed depending on the usage environment or purpose, and through dual curing, improved adhesive strength can be achieved, so it can be used as a higher quality structural adhesive.

[0045] According to the present invention, the dual-curing epoxy adhesive composition comprises an epoxy compound represented by Formula 1, thereby having a superior degree of thermal curing compared to when the epoxy resin is used alone, and accordingly, can provide a cured product with excellent adhesion and reliability.

[0046] The cured product according to the present invention achieves a high Tg of 100°C or higher, can have excellent adhesion even after a high temperature and high humidity environment, has excellent storage stability, and in particular, has the advantage of a smooth adhesive interface.

[0047] The cured material according to the present invention can be usefully applied as a material for forming various optical members and optical devices, and is particularly expected to be usefully applied as an adhesive layer between constituent members, such as camera modules, that require high adhesive strength and water resistance per unit area. Specific details for implementing the invention

[0048] Hereinafter, the dual-curing epoxy adhesive composition and the cured product thereof according to the present invention will be described in detail.

[0049] Unless otherwise defined, technical and scientific terms used herein have the meaning commonly understood by those skilled in the art to which this invention pertains, and descriptions of known functions and configurations that could unnecessarily obscure the essence of the invention are omitted in the following description.

[0050] The singular form used in this specification is intended to include the plural form unless specifically indicated otherwise in the context.

[0051] Additionally, the numerical ranges used in this specification include lower and upper limits and all values ​​within the range, increments logically derived from the form and width of the defined range, all of which are limited values, and all possible combinations of upper and lower limits of the numerical range defined in different forms. Unless otherwise specifically defined in the specification of this invention, values ​​outside the numerical range that may occur due to experimental error or rounding are also included in the defined numerical range.

[0052] The term "comprising" in this specification is an open description having an equivalent meaning to expressions such as "comprising," "containing," "having," or "characterizing," and does not exclude elements, materials, or processes not additionally listed.

[0053] Additionally, the term "substantially" in this specification means that other elements, materials, or processes not listed together with the specified elements, materials, or processes may be present in an amount or to an extent that does not have an unacceptably significant effect on at least one basic and novel technical concept of the invention.

[0054] Additionally, the term "cured product" in this specification may, in a general sense, be a cured product of a curable composition or a cured product of an epoxy adhesive composition. Furthermore, the said cured product may include a semi-cured product.

[0055] Additionally, the term “structural adhesives” in this specification refers to a material used to adhesively bond at least two structural parts constituting a structure together.

[0056] As examined in the background explanation above, when conventional epoxy resin adhesives are double-cured in the order of photocuring and heat curing, the fluidity after photocuring is reduced, which may result in a problem where the degree of curing is lowered during heat curing.

[0057] To solve these problems, the inventors have conducted repeated research on adhesives of various compositions using epoxy resins. As a result, it was confirmed that by including an epoxy compound containing cyanate groups in a dual-curing epoxy adhesive composition, it is possible to achieve adhesive strength in which the adhesive shape is not deformed by external impact after photocuring, and also to achieve significantly improved adhesive strength and water / moisture resistance after subsequent heat curing.

[0058] The present invention will be described in detail below.

[0059] The present invention provides a novel dual-curing epoxy adhesive composition for providing a cured product having excellent curability, adhesive strength, and water / moisture resistance.

[0060] A dual-curing epoxy adhesive composition according to one embodiment of the present invention comprises a base epoxy resin and an epoxy mixed resin comprising an epoxy compound having one or more cyanate ester functional groups and one or more epoxy functional groups; a photocuring agent; and a thermocuring agent.

[0061] Specifically, a dual-curing epoxy adhesive composition according to one embodiment of the present invention comprises a base epoxy resin and an epoxy mixed resin containing an epoxy compound represented by the following chemical formula 1; a photocuring agent; and a thermocuring agent.

[0062] [Chemical Formula 1]

[0063]

[0064] In Chemical Formula 1, A is hydrocarbylene or heterohydrocarbylene, and the hydrocarbylene or heterohydrocarbylene is C1-C 20 Alkyl, -N=C=O, -OC≡N, C6-C 12 Aryl and C1-C 10 It may be further substituted with one or more substituents selected from the alkoxy group.

[0065] Compared to a conventional dual-curing epoxy adhesive composition comprising a base epoxy resin, a photocuring agent, and a thermosetting agent, a dual-curing epoxy adhesive composition comprising an epoxy compound represented by Chemical Formula 1 has the advantage of excellent curing, adhesion, and reliability.

[0066] According to one aspect of the present invention, in the above formula 1, A is C1-C 20 Alkylene, C6-C 20 Arrylene, C6-C 20 Heteroarylene, C3-C20 Cycloalkylene or C3-C 20 It may be a heterocycloalkylene, specifically, C1-C 15 Alkylene, C6-C 15 Arrylene, C6-C 15 Heteroarylene, C3-C 15 Cycloalkylene or C3-C 15 It may be a heterocycloalkylene, specifically, C1-C 10 Alkylene, C6-C 10 Arrylene, C6-C 10 Heteroarylene, C3-C 10 Cycloalkylene or C3-C 10 It may be a heterocycloalkylene, but is not limited thereto.

[0067] As A of Chemical Formula 1 satisfies the above composition, the mixing properties between the dual-curing epoxy adhesive compositions are excellent, allowing them to be mixed homogeneously.

[0068] According to one embodiment of the present invention, the epoxy compound may comprise one or more selected from epoxy compounds represented by the following chemical formulas 2 to 4.

[0069] [Chemical Formula 2]

[0070]

[0071] [Chemical Formula 3]

[0072]

[0073] [Chemical Formula 4]

[0074]

[0075] In the above chemical formulas 2 to 4,

[0076] D1 is a single bond or C1-C 10 It is an alkylene, and Z is -(CR5R6) n - and, R5 and R6 are independently hydrogen, -N=C=O, -OC≡N, C1-C 10 Alkyl and C6-C 12It is an aryl, where n is an integer from 0 to 3, and R1 to R4 are independent of each other, -N=C=O, -OC≡N, C1-C 10 alkyl or C6-C 12 Aril, and

[0077] o, p, and q are independent integers from 0 to 4, and r may be an integer from 0 to 4, but is not limited thereto.

[0078] Specifically, in the above chemical formulas 2 to 4, D1 is a single bond or a C1-C5 alkylene, and Z is -(CR5R6) n - and R5 and R6 are independently hydrogen, -N=C=O, -OC≡N, C1-C8 alkyl and C6-C8 aryl, n is an integer from 0 to 3, R1 to R4 are independently -N=C=O, -OC≡N, C1-C5 alkyl or C6-C8 aryl, o, p and q are independently integers from 0 to 4, and r may be an integer from 0 to 2, but is not limited thereto.

[0079] As the above dual-curing epoxy adhesive composition includes an epoxy compound selected from Formulas 2 to 4, the fluidity of the composition can be maintained to some extent during photocuring, thereby further improving the degree of curing during subsequent heat curing. In particular, as the above epoxy compound is included in the dual-curing epoxy adhesive composition of the present invention, a high Tg can be achieved, and since no gas is generated during heat curing, there is an advantage of a very uniform adhesive interface.

[0080] In addition, since one or more epoxy compounds represented by the above chemical formulas 2 to 4 are included, additional curing can be induced, thereby ensuring a higher degree of curing, adhesion, and reliability than when the base epoxy resin is used alone.

[0081] According to one embodiment of the present invention, the epoxy compound may be an epoxy compound represented by the following chemical formula 5.

[0082] [Chemical Formula 5]

[0083]

[0084] In the above chemical formula 5, D1 is a single bond, a C1-C5 straight-chain alkylene, or a C1-C5 branched alkylene.

[0085] As the above dual-curing epoxy adhesive composition includes the epoxy compound of Formula 5, not only is the degree of curing, adhesion, and reliability excellent, but the duration of adhesion retention can also be further improved.

[0086] In addition, according to one embodiment of the present invention, the epoxy mixed resin may comprise 50 to 400 parts by weight of the epoxy compound of Formula 1 with respect to 100 parts by weight of the base epoxy resin, specifically 50 to 300 parts by weight, specifically 100 to 200 parts by weight, but is not limited thereto.

[0087] In the dual-curing epoxy adhesive composition according to one embodiment of the present invention, the base epoxy resin may be used without limitation as long as it is conventional, and non-limiting examples thereof may be one or more epoxy resins selected from novolak-type epoxy resin, bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, bisphenol E-type epoxy resin, biphenyl-type epoxy resin, triphenylmethane-type epoxy resin and phenol-aralkyl-type epoxy resin, but are not limited thereto.

[0088] According to one embodiment of the present invention, the photocuring agent may include a polyfunctional acrylic compound. The polyfunctional acrylic compound may have an acrylic group having two or more functional groups, specifically three or more functional groups, specifically four or more functional groups, but is not limited thereto.

[0089] Non-limiting examples of the above-mentioned polyfunctional acrylic compounds include dipentaerythritol hexa(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, trimethylpropane tri(meth)acrylate, glycerol tri(meth)acrylate, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, di-trimethylpropane tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, pentaerythritol tetra(meth)acrylate, and trimethylolpropane ethoxylate triacrylate, and may be used as a mixture of one or more selected from these.

[0090] According to one embodiment of the present invention, the thermosetting agent may be a thermosetting agent that does not initiate thermosetting at a desired temperature (room temperature, 25°C) or lower. Non-limiting examples thereof may include imidazole-type thermosetting agents, dihydrazide-type thermosetting agents, or amine-type thermosetting agents, but it is preferable to use amine-type thermosetting agents in terms of improving curing time, storage stability, and adhesive strength. Additionally, commercially available products such as Evonik’s Ancamine 2014AS, ADEKA’s EH-5057PK and EH-4357S may be used.

[0091] According to one embodiment of the present invention, the dual-curing epoxy adhesive composition may comprise 1 to 200 parts by weight of a photocuring agent and 1 to 200 parts by weight of a thermocuring agent with respect to 100 parts by weight of an epoxy mixed resin, specifically, 10 to 150 parts by weight of a photocuring agent and 10 to 150 parts by weight of a thermocuring agent, specifically, 10 to 100 parts by weight of a photocuring agent and 10 to 100 parts by weight of a thermocuring agent, specifically, 15 to 70 parts by weight of a photocuring agent and 15 to 70 parts by weight of a thermocuring agent, specifically, 15 to 50 parts by weight of a photocuring agent and 15 to 50 parts by weight of a thermocuring agent, but is not limited thereto.

[0092] According to one embodiment of the present invention, the dual-curing epoxy adhesive composition may further include a photoinitiator, and the photoinitiator may be used without limitation as long as it is a conventional one.

[0093] Non-limiting examples thereof include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, hydroxydimethylacetophenone, dimethylaminoacetophenone, dimethoxy-2-phenylacetophenone, 3-methylacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 4-chronolocetophenone, 4,4-dimethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 4-hydroxycyclophenylketone, 1-hydroxycyclohexylphenylketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)ketone, benzophenone, p-phenylbenzophenone, 4,4-diaminobenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, anthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 2-aminoanthraquinone, β-chloroanthraquinone, 2-methylthioxantone, 2-ethylthioxantone, 2-chlorothioxantone, 2,4-dimethylthioxantone, 2,4-diethylthioxantone, benzyldimethylketal, diphenylketonebenzyldimethylketal, acetophenonedimethylketal, Examples include p-dimethylaminobenzoic acid ester, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, fluorene, triphenylamine, carbazole, benzyldiphenylsulfide, and tetramethylthiuram monosulfide, and one or more mixtures selected from these may be used. In addition, commercially available products such as Darocur 1173, Irgacure 184, and Igacure 907 (Ciba) may also be used. These may be used individually or in combination of two or more types.

[0094] In the present invention, the amount of the photoinitiator used is not particularly limited, and specifically, it may be 1 to 10 parts by weight per 100 parts by weight of the epoxy mixed resin, specifically 1 to 7 parts by weight, and specifically 1 to 5 parts by weight.

[0095] The above dual-curing epoxy adhesive composition may further include additives as needed, and examples of said additives may include inorganic fillers, stabilizers, and tack promoters, but are not limited thereto.

[0096] As the above-mentioned inorganic filler is included in the above-mentioned dual-curing epoxy adhesive composition, the thermal conductivity is improved during heat curing, thereby having the effect of further improving the degree of curing.

[0097] The above inorganic filler may be, for example, one or more mixtures selected from fumed silica, diatomaceous earth, alumina, zinc oxide, iron oxide, magnesium oxide, tin oxide, titanium oxide, magnesium hydroxide, aluminum hydroxide, magnesium carbonate, barium sulfate, gypsum, calcium silicate, talc, glass beads, fused silica, quartz powder, sericite, talc clay, bentonite, aluminum nitride, silicon nitride, potassium titanate, zeolite, calcia, magnesia, and ferrite, but is not limited thereto.

[0098] In the present invention, the amount of the inorganic filler used is not particularly limited and may be 10 to 150 parts by weight per 100 parts by weight of the epoxy mixed resin, specifically 15 to 100 parts by weight, specifically 20 to 60 parts by weight.

[0099] By including the above stabilizer in the above dual-curing epoxy adhesive composition, it is possible to provide a dual-curing epoxy adhesive composition that has excellent thermal stability under high temperature conditions and also excellent curability.

[0100] The above stabilizer may include one or more stabilizers selected from phenol-based stabilizers, hindered amine-based stabilizers, phosphorus-based stabilizers, boric acid ester-based stabilizers, and alkoxyamine radical-based stabilizers, and specifically may include one or more stabilizers selected from phenol-based stabilizers and boric acid ester-based stabilizers, but is not limited thereto.

[0101] Examples of the above stabilizers include trimethylborate, triethylborate, tri-n-propylborate, triisopropylborate, tri-n-butylborate, tripentylborate, trialylborate, trihexylborate, tricyclohexylborate, trioctylborate, trinonylborate, tridecylborate, tridodecylborate, trihexadecylborate, trioctadecylborate, tris(2-ethylhexyroxy)borane, bis(1,4,7,10)-tetraoxaudecyl)(1,4,7,10,13-pentaoxatetradecyl)(1,4,7-trioxaudecyl)borane, tribenzylborate, triphenylborate, tri-o-tolylborate, tri-m-tolylborate, triethanolamineborate, tri-2-ethylhexylborate, trimethyleneborate, tris(trimethylsilyl)borate, It may be tri-sec-butyl borate, tri-tert-butyl borate, methoxyethoxide boron, hydroquinone, catechol, resorcinol, p-methoxyphenol, t-butylcatechol, t-butyl hydroquinone, pyrogallol, p-benzoquinone, 2,5-di-t-butyl-p-benzoquinone, picric acid, tri-p-nitrophenyl methyl, butylated hydroxytoluene, cyclohexanone oxime cresol, guaiacol, o-isopropylphenol, etc., and specifically, it may be one or more selected from trimethylborate, triethylborate, tri-n-propylborate, triisopropylborate, tri-n-butylborate, tripentylborate, trialylborate, trihexylborate, tricyclohexylborate, and trioctylborate, but is not limited thereto.

[0102] In the present invention, the amount of the stabilizer used is not particularly limited and may be 0.1 to 5 parts by weight per 100 parts by weight of the epoxy mixed resin, specifically 0.1 to 1 part by weight, and specifically 0.1 to 0.5 parts by weight.

[0103] The above adhesion promoter is a substance added to improve the initial adhesion between objects to be bonded or to improve the adhesion duration after curing, and any adhesion promoter or tack promoter known in the art may be used without limitation.

[0104] The above adhesion promoter may be an epoxy-containing silane, an amine-containing silane, or a mercapto-containing silane; those containing epoxy include 2-(3,4-epoxycyclohexyl)-ethyltrimethoxysilane, 3-glycidoxytrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-glycidoxypropyltriethoxysilane; those containing amine groups include N-2(aminoethyl)3-aminopropylmethyldimethoxysilane, N-2(aminoethyl)3-aminopropyltrimethoxysilane, N-2(aminoethyl)3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, and N-phenyl-3-aminopropyltrimethoxysilane; and those containing mercapto Examples include 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltriethoxysilane. The aforementioned components may be used alone or in combination of two or more. It is preferable to use an epoxy-containing silane as the adhesion promoter.

[0105] In the present invention, the amount of the adhesion promoter used is not particularly limited and may be 1 to 50 parts by weight per 100 parts by weight of the epoxy mixed resin, specifically 1 to 20 parts by weight, specifically 1 to 10 parts by weight.

[0106] A dual-curing epoxy adhesive composition according to one embodiment of the present invention may be a one-component type. Accordingly, a primary cured product can be stably formed by photocuring in the first step, and a cured product having improved adhesive strength can be formed by heat curing in the second step. Furthermore, according to the present invention, a cured product with improved adhesive strength and excellent reliability can be provided.

[0107] For example, the photocuring may be performed by irradiating light such as infrared, visible light, ultraviolet, or electron beam with a wavelength of 800 nm or more, and the light may be applied in the range of 100 to 2,000 mW / cm², or 300 to 1,500 mW / cm², or 500 to 1,000 mW / cm² for 1 to 30 seconds, or for 1 to 10 seconds, or for 3 to 5 seconds. Alternatively, it may be performed under irradiation conditions of 2.0 to 10.0 J / cm², preferably 2.0 to 4.0 J / cm², and more preferably 2.0 to 2.5 J / cm².

[0108] For example, the light irradiation means may be a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, an excimer laser, a chemical lamp, a black light lamp, a microwave-excited mercury lamp, a metal halide lamp, a sodium lamp, a fluorescent lamp, an LED-type spot-type UV irradiator, a xenon lamp, or a deep UV lamp, but is not limited thereto.

[0109] For example, the light may be ultraviolet, and the peak wavelength of the ultraviolet may specifically be in the range of 300 to 500 nm.

[0110] For example, the heat curing may be performed at a temperature of 70 to 120°C, preferably at 80 to 100°C, and more preferably at 80 to 90°C.

[0111] In addition, the present invention provides a cured product of a resin composition or a dual-curing epoxy adhesive composition according to the present invention. Specifically, the cured product through dual curing can achieve a UV adhesive strength of 4 kgf or more, specifically 6 kgf or more, specifically in the range of 6 to 10 kgf, and can achieve a dual adhesive strength of 80 kgf or more, specifically 100 kgf or more, specifically in the range of 130 to 250 kgf.

[0112] In addition to such excellent adhesive strength, it can also exhibit excellent moisture resistance even under high temperature and high humidity conditions of 85°C or higher and 85%RH or higher. Accordingly, the cured product according to one embodiment of the present invention can be usefully utilized for purposes such as adhesives, sealants, and coatings. Specifically, it can be usefully applied as an adhesive layer between components such as camera modules that require high adhesive strength and water resistance per unit area, and it can also be utilized as a structural adhesive in the assembly of transportation means such as automobiles, aircraft, and ships, as well as in structures such as civil engineering buildings. This enables diverse applications across various industries by realizing excellent adhesive performance between identical or different materials, such as metal and metal, metal and glass, or metal and carbon fiber.

[0114] The present invention will be described in more detail through the following examples. However, the following examples are merely for reference to explain the present invention in detail and are not limited thereto, and the present invention may be implemented in various forms. Furthermore, unless otherwise defined, all technical and scientific terms have the same meaning as generally understood by one of the art to which the present invention pertains. Additionally, the terms used in the description of the present invention are intended merely to effectively describe specific embodiments and are not intended to limit the present invention.

[0116] [Preparation Example 1]

[0117] Synthesis of epoxy-cyanate compounds

[0118] chemicals 1a 1.0 mol of (e.g.) and 0.5 mol of ephechlorohydrin were dissolved in 1.0 L of DMF and stirred at room temperature until completely dissolved. Subsequently, 0.5 mol of triethyl amine was added and stirred at room temperature for 5 hours. After confirming that the reaction was complete via TLC (thin layer chromatography), the synthesized product was extracted using extractive workup (ethylene acetate / water), and the residual solvent was removed using a rotary evaporator. The half-epoxy compound was purified via silica column chromatography. An epoxy-cyanate compound was synthesized by reacting the synthesized half-epoxy compound with cyanogen bromide. The detailed synthesis method is as follows.

[0120]

[0122] The above-mentioned synthesized half-epoxy compound 2a After dissolving (0.5 mol) in 0.5 L of DMF, cyanogen bromide (Aldrich) (0.6 mol) was added and stirred at room temperature (25°C) for 1 hour. Subsequently, triethyl amine (0.6 mol) was added to initiate the reaction, and stirring was continued at room temperature for an additional 5 hours. After confirming the termination of the reaction via thin layer chromatography (TLC), the synthesized product was extracted using extractive workup (ethylene acetate / water), and residual solvent was removed using a rotary evaporator. Through silica column chromatography, the compound, an epoxy-cyanate compound, was identified. 3a obtained. Structural analysis is 1 H, 13 It was identified via C NMR.

[0123] 3a: 1H NMR (500 MHz, Chloroform) δ7.30 - 7.16 (m, 2H), 7.04 - 6.96 (m, 4H), 6.90 - 6.75 (m, 2H), 4.22 (s, 1H), 4.00 (s, 1H), 3.04 (s, 1H), 2.85 (s, 1H), 2.57 (s, 1H), 1.72 - 1.68 (m, 6H); 13C NMR (125 MHz, Chloroform) δ155.98, 148.45, 144.53, 143.34, 128.34, 127.05, 119.41, 116.36, 109.78, 69.50, 50.93, 45.87, 30.33.

[0125] [Preparation Examples 2 to 4]

[0126] In Step 1 of Example 1 above, the compound 1a An epoxy-cyanate compound was produced by performing the same procedure as in Example 1 above, except that the compound of Table 1 below was used instead.

[0127]

[0128] [Examples 1 to 9 and Comparative Examples 1 to 2]

[0129] A dual-curing epoxy adhesive composition (100g) was prepared with the components and content listed in Table 2 below.

[0130]

[0131] [Evaluation Method]

[0132] [Preparation and Measurement of Adhesion Specimens]

[0133]

[0135] A cell was manufactured by dispensing the dual-curing epoxy adhesive composition of the above examples and comparative examples onto the aluminum lower interface in the form of an inner diameter of 17.3 mm and an outer diameter of 19.1 mm, and then bonding it to the upper interface. At this time, the gap between the lower and upper surfaces was set to 300 μm, and the applied epoxy adhesive was maintained at a level of 85-90 mg. Subsequently, the manufactured cell was cured under the following curing conditions or reliability conditions.

[0136] Afterward, the adhesive strength of each cured cell was measured using a UTM. At this time, the tensile speed was set to 30 mm / min.

[0138] [Curing Conditions]

[0139] After first curing using four light sources (1,000 mW, 5 s) with 365 nm wavelength LED ultraviolet light while maintaining a distance of 25 mm between the adhesive and the light source in the horizontal direction of the cell, the cell was heated in a thermal circulating oven at 80°C for 30 minutes to perform second curing. The adhesive strength of the second-cured specimen was measured after leaving it at room temperature for 24 hours.

[0141] [Reliability Conditions]

[0142] The time before the adhesive strength drops below the reliability level is based on the time after exposing the specimen, which has completed the above curing conditions, to conditions of 85℃ and 85%RH using a constant temperature / humidity chamber.

[0144] [Dispensing Evaluation]

[0145] 1) Dispensing method

[0146] After packaging the dual-curing adhesive composition in a 10cc syringe, degassing was performed using a centrifuge, and the centrifugation was carried out at 3000 rpm for 90 seconds.

[0147] Afterward, stabilization was carried out at room temperature for 1 hour. Subsequently, using a desktop robot (model: SHOTmini 200Sx), the interface and height were set to 0.3-0.5 mm, the speed to 5 mm / s, and the needle was 18 G.

[0149] 2) Evaluation Method

[0150] Leveling performance was evaluated by assessing the maintenance of the coating thickness for one hour after dispensing, which was conducted via microscopic observation. The dispensing volume was evaluated as the coating level being 85-90 mg when dispensing was repeated 10 times.

[0152] [Evaluation Results]

[0153] The results of the physical properties obtained through the above evaluation method are shown in Table 3 below.

[0154]

[0155] As shown in Table 3 above, Examples 1 to 6 exhibited an adhesive strength of 8 kgf or more after UV curing, and all exhibited a very excellent adhesive strength of 100 kgf or more after UV / thermal curing. In particular, Examples 1 to 3 all exhibited a very high adhesive strength of 140 kgf or more after UV / thermal curing.

[0156] That is, after UV / thermal curing, the cyanate functional group of the dual-curing epoxy adhesive composition and the epoxy functional group of the epoxy resin were both cross-linked by the amine-based thermosetting agent, thereby achieving very high adhesion.

[0157] In addition, the dual-curing epoxy adhesive composition according to the present invention not only exhibits excellent adhesive strength under reliability conditions, but also further increases adhesive strength as additional curing proceeds under 85 / 85 reliability conditions.

[0158] That is, the cured material according to the present invention not only has excellent moisture resistance as its adhesive strength does not decrease under constant temperature / humidity conditions (85℃), but also has further improved adhesive strength as additional curing proceeds.

[0159] In addition, all dual-curing epoxy adhesive compositions according to the present invention were capable of achieving a high Tg of 100°C or higher.

[0160] In addition, in the case of a cured product obtained by curing the dual-curing epoxy adhesive composition of the present invention, no decrease in adhesive strength due to rapid gas generation during curing was observed, and it was confirmed that the adhesive interface was evenly cured even after curing.

[0161] However, in the case of Example 6, no stabilizer was used, so the storage stability at room temperature was less than one day, making it unusable as a product, and as in Example 7, when no adhesion promoter was used, the adhesive strength dropped sharply after 24 hours at 85 / 85.

[0162] Meanwhile, in the case of Comparative Example 1, which used epoxy resin alone, an adhesive strength of 100 kgf or less was achieved after double curing, and the Tg was also 75℃, showing a lower value compared to the examples.

[0163] Comparative Example 2, which used cyanate-ester resin alone, was able to achieve a high Tg, but due to the excessively rapid reaction, it exhibited an internal temperature (150°C) higher than the heat supplied from the outside (80°C). In addition, the gas contained in the resin was released rapidly, preventing the adhesive interface from curing evenly, which actually reduced the adhesive strength. Furthermore, when using cyanate-ester alone, it is difficult to control the excessively fast reaction rate, and due to the excessively high viscosity, very high pressure is required for dispensing, resulting in an uneven discharge volume.

[0164] Therefore, when using the cured product of the dual-curing epoxy adhesive composition according to the present invention, photocuring, thermal curing, or dual curing combining these can be selected and performed depending on the usage environment or purpose, and furthermore, enhanced adhesive strength can be achieved through dual curing. With the realization of such physical properties, it is expected that it can be usefully applied as an adhesive layer between components, such as camera modules, where high adhesive strength and water resistance per unit area are required.

[0166] As described above, the present invention has been explained by specific details, limited embodiments, and comparative examples; however, this is provided merely to aid in a more comprehensive understanding of the invention, and the invention is not limited to the above embodiments. Those skilled in the art can make various modifications and variations from this description.

[0167] Accordingly, the scope of the present invention is not limited to the described embodiments, and all things equivalent to or having equivalent variations to the claims set forth below, as well as the claims set forth below, shall be considered to fall within the scope of the concept of the present invention.

Claims

Claim 1 A dual-curing epoxy adhesive composition comprising: a base epoxy resin and an epoxy mixed resin containing an epoxy compound represented by the following chemical formula 1; a photocuring agent; and a thermosetting agent; wherein, with respect to 100 parts by weight of the base epoxy resin, 50 to 300 parts by weight of the epoxy compound represented by the chemical formula 1, and with respect to 100 parts by weight of the epoxy mixed resin, 10 to 100 parts by weight of the photocuring agent and 10 to 100 parts by weight of the thermosetting agent. [Chemical Formula 1] In Chemical Formula 1, A is hydrocarbylene or heterohydrocarbylene, and the hydrocarbylene or heterohydrocarbylene is C1-C 20 Alkyl, -N=C=O, -OC≡N, C6-C 12 Aryl and C1-C 10 It may be further substituted with one or more substituents selected from the alkoxy group. Claim 2 In claim 1, in the above chemical formula 1, A is C1-C 20 Alkylene, C6-C 20 Arrylene, C6-C 20 Heteroarylene, C3-C 20 Cycloalkylene or C3-C 20 A heterocycloalkylene, dual-curing epoxy adhesive composition. Claim 3 A dual-curing epoxy adhesive composition according to claim 2, wherein the epoxy compound is one or more selected from the epoxy compounds represented by the following chemical formulas 2 to 4. [Chemical Formula 2] [Chemical Formula 3] [Chemical Formula 4] In the above chemical formulas 2 to 4, D1 is a single bond or C1-C 10 It is an alkylene, and Z is -(CR5R6) n - and, R5 and R6 are independently hydrogen, -N=C=O, -OC≡N, C1-C 10 Alkyl and C6-C 12 It is an aryl, where n is an integer from 0 to 3, R1 to R4 are independent of each other, -N=C=O, -OC≡N, C1-C 10 alkyl or C6-C 12 It is an aryl, and o, p and q are independent integers from 0 to 4, and r is an integer from 0 to 4. Claim 4 In claim 3, in the above chemical formulas 2 to 4, D1 is a single bond or a C1-C5 alkylene, and Z is -(CR5R6) n A dual-curing epoxy adhesive composition in which - and R5 and R6 are independently hydrogen, -N=C=O, -OC≡N, C1-C8 alkyl and C6-C8 aryl, n is an integer from 0 to 3, R1 to R4 are independently -N=C=O, -OC≡N, C1-C5 alkyl or C6-C8 aryl, o, p and q are independently integers from 0 to 4, and r is an integer from 0 to 2. Claim 5 In claim 3, the epoxy compound is a dual-curing epoxy adhesive composition represented by the following chemical formula 5. [Chemical Formula 5] In the above chemical formula 5, D1 is a single bond, a C1-C5 straight-chain alkylene, or a C1-C5 branched alkylene. Claim 6 A dual-curing epoxy adhesive composition according to claim 1, wherein the epoxy mixed resin comprises 100 to 200 parts by weight of the epoxy compound of Formula 1 per 100 parts by weight of the base epoxy resin. Claim 7 A dual-curing epoxy adhesive composition according to claim 1, wherein the base epoxy resin is one or more mixtures selected from novolak-type epoxy resin, bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, bisphenol E-type epoxy resin, biphenyl-type epoxy resin, triphenylmethane-type epoxy resin, phenol-aralkyl-type epoxy resin, halogenated epoxy resin, alicyclic epoxy resin, rubber-modified epoxy resin, aliphatic polyglycidyl-type epoxy resin, glycidyl amine-type epoxy resin, polyglycol epoxy resin, and cardanol epoxy resin. Claim 8 A dual-curing epoxy adhesive composition according to claim 1, wherein the photocuring agent comprises a polyfunctional acrylic compound. Claim 9 A dual-curing epoxy adhesive composition according to claim 1, wherein the thermosetting agent comprises an amine-based compound. Claim 10 In claim 1, the dual-curing epoxy adhesive composition further comprises a photoradical initiator. Claim 11 In claim 1, the dual-curing epoxy adhesive composition comprises 15 to 70 parts by weight of a photocuring agent and 15 to 70 parts by weight of a thermosetting agent, based on 100 parts by weight of an epoxy mixed resin. Claim 12 In claim 1, the dual-curing epoxy adhesive composition further comprises an inorganic filler. Claim 13 A dual-curing epoxy adhesive composition according to claim 12, wherein the inorganic filler is one or more mixtures selected from fumed silica, diatomaceous earth, alumina, zinc oxide, iron oxide, magnesium oxide, tin oxide, titanium oxide, magnesium hydroxide, aluminum hydroxide, magnesium carbonate, barium sulfate, gypsum, calcium silicate, talc, glass beads, fused silica, quartz powder, sericite, talc clay, bentonite, aluminum nitride, silicon nitride, potassium titanate, zeolite, calcia, magnesia, and ferrite. Claim 14 In claim 1, the dual-curing epoxy adhesive composition further comprises a stabilizer. Claim 15 In claim 1, the dual-curing epoxy adhesive composition further comprises an adhesion promoter. Claim 16 A cured product of any one of claims 1 to 15 of an epoxy adhesive composition.

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