Curable composition, semi-cured product, substrate with semi-cured product, laminate, and method for manufacturing the same.

Abstract

The present invention provides a curable composition that possesses tackiness and plastic deformability in a semi-cured state and excellent strength after thermal curing, a semi-cured product of the curable composition, a substrate coated with the semi-cured product, a laminate containing the curable composition, and a method for manufacturing the same. [Solution] The curable composition according to the present disclosure contains a monofunctional (meth)acrylate (A1) and a polyfunctional (meth)acrylate (A2), which each contain a linear aliphatic hydrocarbon group that may have an ether bond and / or ester bond between carbon atoms and may have an alicyclic ring with a heteroatom as a substituent. A photopolymerization initiator (B), an epoxy resin (C), a thermosetting agent (D), and a tackifier (E) containing a terpene phenol resin.

Description

[Technical Field]

[0001] The present invention relates to a curable composition, a semi-cured product, a substrate with a semi-cured product, a laminate, and a method for producing the same. [Background technology]

[0002] Adhesives containing photocurable and thermosetting components are known. For example, Patent Document 1 discloses a composition capable of two different curing methods, photocuring and thermocuring, comprising a cyclic ether compound having a cyclic ether group, a radical polymerizable compound having a radical polymerizable group, a photo-radical initiator capable of polymerizing the radical polymerizable groups together, and a thermopolymerization initiator capable of polymerizing the cyclic ether groups together. Patent Document 1 also discloses a method of using the composition, in which the composition is applied to a substrate, photocured by polymerizing the radical polymerizable groups together by light irradiation, the semi-cured product is applied to an adherend, and the adherends are bonded together with minimal misalignment by heat curing. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] International Publication No. 2019 / 017418 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] The present invention provides a curable composition that is tacky and plastically deformable in a semi-cured state and has excellent strength after thermal curing, a semi-cured product of the curable composition, a substrate with the semi-cured product, a laminate containing the curable composition, and a method for manufacturing the same. [Means for solving the problem]

[0005] The present invention includes the following embodiments. [1] A curable composition comprising a monofunctional (meth)acrylate (A1) having a linear aliphatic hydrocarbon group which may have an ether bond and / or ester bond between carbon atoms and which may have an alicyclic ring which may have a heteroatom as a substituent, a polyfunctional (meth)acrylate (A2), a photopolymerization initiator (B), an epoxy resin (C), a thermosetting agent (D), and a tackifier (E) which may contain a terpene phenol resin. [2] The curable composition according to [1], wherein the terpene phenol resin has a softening point of 50°C or higher. [3] The curable composition according to [1] or [2], wherein the polyfunctional (meth)acrylate (A2) has a molecular weight of 20,000 or less. [4] The curable composition according to any one of [1] to [3], wherein the epoxy resin (C) has an aromatic ring or alicyclic structure. [5] The curable composition according to any one of [1] to [4], wherein the photopolymerization initiator (B) has a carbonyl group. [6] The curable composition according to any one of [1] to [5], wherein the thermosetting agent (D) is an amine or a quaternary ammonium salt. [7] A semi-cured product of any of the curable compositions described in [1] to [6]. [8] A substrate comprising the semi-cured material described in [7], Substrate with semi-cured material. [9] A first substrate is provided with a cured product of any of the curable compositions described in [1] to [6], and a second substrate, in this order. Laminated structure.

[10] The laminate according to [9], wherein the first substrate and / or the second substrate has an uneven shape.

[11] The step of placing the curable composition described in any of [1] to [6] on a first substrate, The steps include: irradiating the curable composition with light to form a semi-cured product; The steps include placing a second substrate on the semi-cured material, The process includes the step of heating the semi-cured material while applying pressure to the second substrate in the direction of the first substrate, A method for manufacturing laminates.

[12] A step of disposing the curable composition according to any one of [1] to [6] on a first substrate; A step of forming a semi-cured product by irradiating the curable composition with light; A step of disposing a second substrate on the semi-cured product; A step of heating and melting the semi-cured product; A step of heating the semi-cured product at a temperature higher than that in the above step to thermally cure it, and A method for manufacturing a laminate. [Advantages of the Invention]

[0006] According to the present invention, it is possible to provide a curable composition having adhesiveness and plastic deformability in a semi-cured state and excellent strength after thermal curing, a semi-cured product of the curable composition, a substrate with the semi-cured product, a laminate containing the curable composition, and a method for manufacturing the same. [Brief Description of the Drawings]

[0007] [Figure 1] It is a schematic process diagram showing an example of a method for manufacturing a laminate according to this embodiment. [Figure 2] (a) It is a schematic process diagram for explaining a method for evaluating the photocurability of a semi-cured product. (b) It is a schematic process diagram for explaining a method for evaluating the holding force of a semi-cured film. [Embodiments for Carrying Out the Invention]

[0008] Hereinafter, each embodiment of the curable composition according to the present invention, a semi-cured product of the curable composition, a substrate with the semi-cured product, a laminate containing the curable composition, and a method for manufacturing the same will be described. In the present invention, (meth)acrylate is a general term for acrylate and methacrylate, and (meth)acryloyl group and the like are the same. In this specification, the curable composition after photocuring may be referred to as a "semi-cured product", and the curable composition after photocuring and thermal curing may be referred to as a "cured product". Note that the semi-cured product and the cured product may have fluidity. Furthermore, unless otherwise specified, the "~" symbol indicating a numerical range includes both the lower and upper limits.

[0009] [Curable composition] The curable composition of this embodiment contains a monofunctional (meth)acrylate (A1) and a polyfunctional (meth)acrylate (A2), a photopolymerization initiator (B), an epoxy resin (C), a thermosetting agent (D), and a tackifier (E) containing a terpene phenol resin. The monofunctional (meth)acrylate (A1) may have a linear aliphatic hydrocarbon group having an ether bond and / or ester bond between carbon atoms and may have an alicyclic ring having a heteroatom as a substituent.

[0010] The curable composition of this embodiment achieves both plastic deformability and tackiness in the semi-cured state by using a combination of polyfunctional (meth)acrylate (A2). The curable composition of this embodiment contains epoxy resin (C), which causes it to heat-cur when heated and provides excellent strength after heat curing. Furthermore, the curable composition of this embodiment contains a tackifier (E) containing terpene phenol resin. Since the terpene phenol resin contained in the tackifier (E) is solid at room temperature, the solid terpene phenol resin acts as a plasticizer in the semi-cured state, achieving both flexibility (plastic deformability) in the semi-cured state and curing strength after heating. Moreover, the curable composition of this embodiment has viscosity, and maintains compositional uniformity even when stretched to conform to the surface shape of the adherend. As a result, the curable composition of this embodiment possesses tackiness and plastic deformability in the semi-cured state and excellent strength after heat curing, making it suitable for use as an adhesive, for example.

[0011] The curable composition of this embodiment (hereinafter also referred to as "this curable composition") contains at least a monofunctional (meth)acrylate (A1), a polyfunctional (meth)acrylate (A2), a photopolymerization initiator (B), an epoxy resin (C), a thermosetting agent (D), and a tackifier (E) containing a terpene phenol resin, and may further contain other components. The components that may be included in this composition will be described below.

[0012] <Monofunctional (meth)acrylate (A1)> This curable composition uses a combination of monofunctional (meth)acrylate and polyfunctional (meth)acrylate as photocurable components. This curable composition uses a monofunctional (meth)acrylate (A1) as the monofunctional (meth)acrylate, which may have an ether bond and / or ester bond between carbon atoms and may have an alicyclic ring with a heteroatom as a substituent. The compatibility with each component described later is improved by this specific monofunctional (meth)acrylate (A1).

[0013] Linear aliphatic hydrocarbons may have double and / or triple bonds as carbon-carbon bonds. On the other hand, from the viewpoint of the stability of the compound in the composition, saturated aliphatic hydrocarbons consisting of single bonds are preferred for linear aliphatic hydrocarbons. The number of carbon atoms in the linear aliphatic hydrocarbon is preferably 1 to 36, more preferably 2 to 24, and even more preferably 4 to 12, from the viewpoint of the tackiness and plastic deformability of the composition when it is semi-cured, and compatibility with other components. Note that the carbon atoms that constitute the ester bond (-COO-) are not included in the carbon number calculation.

[0014] In the alicyclic ring which may have the heteroatoms described above, examples of heteroatoms include oxygen atoms, nitrogen atoms, and silicon atoms. Specific examples of alicyclic rings which may have heteroatoms include cycloalkyl groups having 3 to 8 carbon atoms, such as cyclopropyl groups, cyclobutyl groups, cyclopentyl groups, cyclohexyl groups, cycloheptyl groups, and cyclooctyl groups; polycyclic aliphatic hydrocarbon groups having 7 to 12 carbon atoms, such as bicyclo[2,2,1]hexyl groups, bicyclo[2,2,2]octyl groups, and adamantyl groups; and saturated heterocyclic groups such as tetrahydrofuryl groups, tetrahydropyranyl groups, pyrrolidyl groups, and piperidyl groups. The substitution position of the alicyclic ring is not particularly limited, but from the viewpoint of compatibility with other components and tackiness and plastic deformability during semi-curing, the end opposite to the (meth)acryloyl group of the linear aliphatic hydrocarbon group is preferred.

[0015] As the monofunctional (meth)acrylate (A1), a compound represented by the following formula (a1) is preferred. CH2=CHR 1 COO-[(CH2) n1 -A 1 n2 -(CH2) n3 -R 2 ···(a1) However, R 1 is a hydrogen atom or a methyl group, A 1 are each independently an ether bond (-O-) or an ester bond (-COO-), R 2 is a hydrogen atom or an alicyclic ring which may have a hetero atom, n1 are each independently an integer of 1 to 4, preferably 1 or 2, n2 is an integer of 0 to 6, n3 is an integer of 1 to 36, preferably 2 to 24, more preferably 4 to 12, n1 (when there are a plurality, the sum of all n1) + n3 is 1 to 36.

[0016] Among them, from the viewpoints of compatibility with other components and adhesiveness and plastic deformability during semi-curing, when n2 is 0, R 2 is preferably a hydrogen atom, when n2 is 1 or more, n3 is preferably 1 to 6. Also, from the viewpoint of easy availability of the monofunctional (meth)acrylate (A1), when n2 is 1 or more, a plurality of A 1 are preferably the same, and a plurality of n1 are preferably the same.

[0017] ​Specific examples of monofunctional (meth)acrylates (A1) include alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, and dodecyl (meth)acrylate; (Poly)alkylene glycol (meth)acrylates such as 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, methoxydiethylene glycol (meth)acrylate, methoxytriethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, and ethoxydiethylene glycol (meth)acrylate; Examples include tetrahydrofurfuryl alcohol (meth)acrylic acid polymer ester, ethoxyethoxyethanol acrylic acid polymer ester, and 1,6-hexanediol acrylic acid polymer ester. Monofunctional (meth)acrylate (A1) can be used alone or in combination of two or more types.

[0018] Furthermore, the monofunctional (meth)acrylate (A1) is preferably liquid at 20°C, and more preferably liquid at 5-40°C, from the viewpoint of the application and handling properties of the composition.

[0019] The molecular weight of the monofunctional (meth)acrylate (A1) is preferably 1000 or less, more preferably 80 to 800, and even more preferably 150 to 600, from the viewpoint of the plastic deformability, tackiness, and compatibility with the terpene phenol resin contained in the tackifier (E) of the semi-cured state of the composition.

[0020] The viscosity of the monofunctional (meth)acrylate (A1) at 25°C is preferably 0.1 to 100 mPa·s, and particularly preferably 1 to 20 mPa·s, from the viewpoint of compositional uniformity and coatability.

[0021] Monofunctional (meth)acrylate (A1) may be synthesized or commercially available. Examples of commercially available products include ethoxydiethylene glycol acrylate (Light Acrylate EC-A, manufactured by Kyoeisha Chemical Co., Ltd.), nonyl acrylate (Viscote #197, manufactured by Osaka Organic Chemical Industry Co., Ltd.), and tetrahydrofurfuryl alcohol acrylic acid polymer ester (Viscote #150D, manufactured by Osaka Organic Chemical Industry Co., Ltd.).

[0022] <Polyfunctional (meth)acrylate (A2)> The polyfunctional (meth)acrylate (A2) is a compound having two or more (meth)acryloyl groups in its molecule. By combining the monofunctional (meth)acrylate (A1) and the polyfunctional (meth)acrylate (A2), both plastic deformability and tackiness can be achieved in the semi-cured state of the composition. The number of functional groups in the polyfunctional (meth)acrylate (A2) is preferably two or three.

[0023] The structure of the polyfunctional (meth)acrylate (A2) is not particularly limited, and examples include polyester polyols, polyether polyols, polycarbonate polyols, polyols whose skeleton is a hydrocarbon group, etc., in which a (meth)acryloyl group is dehydrated and condensed to a hydroxyl group, or urethane acrylates in which a (meth)acryloyl group is bonded to the polyol via an isocyanate. The alkylene in the alkylene glycol may be linear, branched like trimethylolpropane, or have a ring structure. As for the ring structure, tricyclo[5.2.1.0 2,6 This may also include polycyclic aliphatic hydrocarbons such as decane.

[0024] Specific examples of polyfunctional (meth)acrylates (A2) include: Difunctional (meth)acrylates such as ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, hexanediol di(meth)acrylate, propylene glycol di(meth)acrylate, glycerol di(meth)acrylate, triethylene glycol di(meth)acrylate, and tricyclodecanedimethanol di(meth)acrylate; Trifunctional (meth)acrylates such as trimethylolpropane tri(meth)acrylate, glycerol tri(meth)acrylate, and pentaerythritol tri(meth)acrylate; Examples include polyether-based urethane (meth)acrylates, polyester-based urethane (meth)acrylates, and polycarbonate-based urethane (meth)acrylates. Polyfunctional (meth)acrylates (A2) can be used individually or in combination of two or more types.

[0025] The molecular weight of the polyfunctional (meth)acrylate (A2) is preferably in the range of 250 to 20,000, considering the plastic deformability and tackiness of the composition in its semi-cured state, and the adhesiveness after curing. When the skeleton of the polyfunctional (meth)acrylate (A2) is a hydrocarbon group, the molecular weight is preferably 250 to 1,000, and more preferably 280 to 500. When the skeleton of the polyfunctional (meth)acrylate (A2) is a polyester polyol, polyether polyol, or polycarbonate polyol, the molecular weight is preferably 1,000 to 20,000, and more preferably 2,000 to 18,000. If the polyfunctional (meth)acrylate (A2) has a molecular weight distribution, the above molecular weights are weight-average molecular weights.

[0026] The polyfunctional (meth)acrylate (A2) is preferably liquid at 20°C, and more preferably liquid at 5-40°C, from the viewpoint of the application and handling of the composition.

[0027] The polyfunctional (meth)acrylate (A2) may be synthesized or a commercially available product may be used. Examples of commercially available products include tricyclodecanedimethanol diacrylate (Yupimer UV SA-1002N, manufactured by Mitsubishi Chemical Corporation), trimethylolpropane triacrylate (Viscote #295, manufactured by Osaka Organic Chemical Industry Co., Ltd.), and polycarbonate-based urethane acrylate (UN9200A, manufactured by Negami Kogyo Co., Ltd.).

[0028] The ratio of monofunctional (meth)acrylate (A1) to polyfunctional (meth)acrylate (A2) can be adjusted as appropriate. From the viewpoint of achieving both plastic deformability and tackiness in the semi-cured state of the composition, the content of the polyfunctional (meth)acrylate (A2) is preferably 0.5 to 15 parts by mass, and more preferably 0.8 to 12 parts by mass, per 100 parts by mass of the monofunctional (meth)acrylate (A1).

[0029] <Other (meth)acrylates> This composition may contain other (meth)acrylates to the extent that it exhibits the effects of the present invention. Examples of other (meth)acrylates include monofunctional (meth)acrylates having hydroxyl groups or amino groups, monofunctional (meth)acrylates having phenyl groups, and monofunctional (meth)acrylates in which a ring is directly bonded to a (meth)acryloyl group (in formula (a1) above, n2 and n3 are 0), such as isobornyl (meth)acrylate. The content of the other (meth)acrylate is preferably 30 parts by mass or less, and more preferably 20 parts by mass or less, per 100 parts by mass of monofunctional (meth)acrylate (A1).

[0030] <Photopolymerization initiator (B)> This curable composition contains a photopolymerization initiator (B) because it forms a semi-cured product upon light irradiation. The photopolymerization initiator (B) can be used alone or in combination of two or more types.

[0031] Examples of photopolymerization initiators include photoradical polymerization initiators, photocationic polymerization initiators, and photoanionic polymerization initiators, and any of these may be used in combination. This curable composition preferably contains a photoradical polymerization initiator from the viewpoint of the rate of semi-cured product formation and the stability of the semi-cured product after light irradiation.

[0032] The photoradical polymerization initiator can be any compound that generates radicals upon irradiation with light, and can be selected and used as appropriate. Specific examples of photoradical polymerization initiators include: Carbonyl photopolymerization initiators such as benzophenone, diacetyl, benzyl, benzoin, ω-bromoacetophenone, chloroacetone, acetophenone, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetone, p-dimethylaminoacetophenone, p-dimethylaminopropiophenone, 2-chlorobenzophenone, p,p'-bisdiethylaminobenzophenone, Michler ketone, benzoin methyl ether, benzoin isobutyl ether, benzoin-n-butyl ether, benzyl dimethyl ketal, hydroxymethylphenylacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-one, 2-hydroxy-2-methyl-1-phenyl-propanone polymer, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, methylbenzoyl formate, 2,2-diethoxyacetophenone, and 4-N,N'-dimethylacetophenones; Sulfide-based photopolymerization initiators such as diphenyl disulfide and dibenzyl disulfide; Quinone-based photopolymerization initiators such as benzoquinone and anthraquinone; UV photoinitiators such as azobisisobutyronitrile and 2,2'-azobispropane, which are azo-based photopolymerization initiators; Examples include visible light initiators such as 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholinophenyl)-butan-1-one, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

[0033] The photocationic polymerization initiator can be any compound that generates cations upon irradiation with light, and can be selected and used as appropriate. Examples of photocationic polymerization initiators include aromatic diazonium salts, aromatic iodonium salts, aromatic sulfonium salts, and the like.

[0034] The photo-anionic polymerization initiator can be any compound that generates anions upon irradiation with light, and can be selected and used as appropriate. Examples of photo-anionic polymerization initiators include onium salts and carbamates.

[0035] The photopolymerization initiator (B) is preferably a carbonyl-based photopolymerization initiator having a carbonyl group, and among these, hydroxymethylphenylacetophenone is preferred, from the viewpoint of sensitivity and other factors.

[0036] The photopolymerization initiator (B) can be a commercially available product, and can be used alone or in combination of two or more types. Examples of commercially available products include hydroxymethylphenylacetophenone (Omnirad1173, manufactured by IGM Resins).

[0037] From the viewpoint of curability and the strength of the cured composition, the content of the photopolymerization initiator (B) is preferably 0.5 to 40 parts by mass, and more preferably 1 to 30 parts by mass, per 100 parts by mass of monofunctional (meth)acrylate (A1).

[0038] <Epoxy resin (C)> This curable composition contains epoxy resin (C) as a thermosetting component. The epoxy resin (C) may be liquid or solid at 25°C and 1 atm. Here, "solid" means that, before mixing with the monofunctional (meth)acrylate (A1), it is solid (crystalline), glassy, ​​or rubbery at 25°C and 1 atm. When the epoxy resin (C) is liquid, its compatibility with the monofunctional (meth)acrylate (A1) is improved, and the flexibility (plastic deformability) and surface shape conformability to the adherend in the semi-cured state of the composition are improved. When the epoxy resin (C) is solid, it also functions as a plasticizer in the composition, achieving both flexibility in the semi-cured state and curing strength after heating.

[0039] When the epoxy resin (C) is solid at 25°C and 1 atm, from the viewpoint of the plastic deformability of the semi-cured product of this composition, the softening point of the epoxy resin (C) is preferably lower than the temperature at which thermal curing progresses, specifically 25 to 80°C, more preferably 30 to 70°C, and even more preferably 40 to 65°C. By heating to a temperature higher than the softening point of the epoxy resin (C), this composition exhibits excellent conformability to the surface shape of the adherend even in its semi-cured state.

[0040] Furthermore, the epoxy equivalent of epoxy resin (C) is preferably 100 to 400 g / eq, more preferably 120 to 350 g / eq, and even more preferably 130 to 300 g / eq, from the viewpoint of film strength after heat curing.

[0041] Examples include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol E type epoxy resin, hydrogenated bisphenol A type epoxy resin, naphthalene type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, bisphenol F novolac type epoxy resin, alicyclic epoxy resin, aliphatic chain epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, hydantoin type epoxy resin, isocyanurate type epoxy resin, and phenol novolac type epoxy resin having a triphenolmethane skeleton. In addition, diglycidyl ethers of difunctional phenols, diglycidyl ethers of difunctional alcohols and their halides and hydrogenated products can also be used as epoxy resins. Furthermore, various polyfunctional epoxy resins can also be used as epoxy resins. In particular, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol E type epoxy resin, hydrogenated bisphenol A type epoxy resin, naphthalene type epoxy resin, alicyclic epoxy resin, and cresol novolac type epoxy resin are preferred in terms of flexibility in the semi-cured state of the curable composition, storage modulus of elasticity and heat resistance of the thermo-cured curable composition.

[0042] The epoxy resin (C) can be a commercially available product, and one type can be used alone or two or more types can be used in combination. Examples of commercially available products include bisphenol A type epoxy resin (EXA-850CRP, manufactured by DIC Corporation), bisphenol F type epoxy resin (EXA-830CRP, manufactured by DIC Corporation), bisphenol E type epoxy resin (EPOX-MK R1710, manufactured by Printec Co., Ltd.), hydrogenated bisphenol A type epoxy resin (jER YX8034, manufactured by Mitsubishi Chemical Corporation), naphthalene type epoxy resin (HP-4032D, manufactured by DIC Corporation), alicyclic epoxy resin (Celoxide 2021P, manufactured by Daicel Corporation), and cresol novolac type epoxy resin (N655-EXP-S, manufactured by DIC Corporation).

[0043] From the viewpoint of curability and the strength of the cured composition, the content of epoxy resin (C) is preferably 25 to 75 parts by mass, and more preferably 35 to 65 parts by mass, out of 100 parts by mass of the total of monofunctional (meth)acrylate (A1) and epoxy resin (C).

[0044] <Thermosetting agent (D)> The thermosetting agent (D) can be appropriately selected from known epoxy curing agents. Examples of thermosetting agents (D) include epoxy curing agents such as amine compounds, imidazole compounds, acid anhydride compounds, organophosphinic acid compounds, phenolic compounds, hydrazide compounds, and carbazide compounds, as well as thermoacid generators (cationic polymerization initiators).

[0045] As the thermosetting agent (D), amine compounds are preferred from the viewpoint of reactivity, and polyamines are more preferred. Examples of polyamines include aliphatic polyamines such as diethylenetriamine, triethylenetetraamine, tetraethylenepentamine, trimethylhexamethylenediamine, and 2-methylpentamethylenediamine; alicyclic polyamines such as isophoronediamine, 1,3-bisaminomethylcyclohexane, bis(4-aminocyclohexyl)methane, norbornenediamine, and 1,2-diaminocyclohexane; piperazine-type polyamines such as N-aminoethylpiperazine and 1,4-bis(2-amino-2-methylpropyl)piperazine; and aromatic polyamines such as diaminodiphenylmethane, m-phenylenediamine, m-xylenediamine, diaminodiphenylsulfone, diethyltoluenediamine, trimethylenebis(4-aminobenzoate), and polytetramethyleneoxide-di-p-aminobenzoate.

[0046] Examples of onium salts that can be used as thermal acid generators include quaternary ammonium salts, iodonium salts, sulfonium salts, phosphonium salts, and diazonium salts, with quaternary ammonium salts being preferred among them.

[0047] The thermosetting agent (D) can be a commercially available product, and one type can be used alone or two or more types can be used in combination. Examples of commercially available products include polyamine-type thermosetting agents (EH5030S, manufactured by ADEKA Corporation) and quaternary ammonium salt-based thermoacid generators (CXC1612, manufactured by KING Corporation).

[0048] The thermosetting agent (D) may be used alone or in combination of two or more types. The content of the thermosetting agent (D) is preferably 1 to 70 parts by mass, and more preferably 2 to 60 parts by mass, per 100 parts by mass of epoxy resin (C). When the above epoxy curing agent is used as the thermosetting agent, the content of the curing agent (D) is preferably 10 to 70 parts by mass, and more preferably 25 to 60 parts by mass, per 100 parts by mass of epoxy resin (C). When the above thermal acid generating agent is used as the thermosetting agent, the content of the curing agent (D) is preferably 1 to 10 parts by mass, and more preferably 2 to 8 parts by mass, per 100 parts by mass of epoxy resin (C).

[0049] <Tackifier (E)> This curable composition contains a tackifier (E) to enhance tackiness in the semi-cured state. Preferably, the tackifier (E) contains a terpene phenol resin that is solid at 25°C and 1 atm. By containing a solid terpene phenol resin, the tackifier (E) functions as a plasticizer in the composition, achieving both flexibility in the semi-cured state and curing strength after heating.

[0050] In this curable composition, the terpene-phenol resin is a polymer containing structures derived from terpenes and structures derived from phenols. Examples of terpene-phenol resins include copolymers of terpenes and phenols (terpene-phenol copolymer resins) and phenol-modified homopolymers of terpenes (phenol-modified terpene resins). Terpenes and phenols can be polymerized by reactions such as the Friedel-Crafts reaction. Examples of the above terpenes include isoprene (C5H8) or its polymers, and examples of such polymers include monoterpenes (C5H8). 10 H 16), sesquiterpenes (C 15 H 24 ), diterpene (C 20 H 32 Examples of terpenes include myrcene, allocimene, ocimene, α-pinene, β-pinene, dipentene, limonene, α-phellandrene, α-terpinene, γ-terpinene, terpinolene, 1,8-cineole, 1,4-cineole, α-terpineol, β-terpineol, γ-terpineol, camphene, tricyclene, sabinene, paramentadienes, and carenes. Specific examples of phenols include phenol, cresol, xylenol, propylphenol, norylphenol, hydroquinone, resorcinol, methoxyphenol, bromophenol, bisphenol A, and bisphenol F.

[0051] The tackifier (E) containing terpene phenol resin can be a commercially available product, such as YS Polystar K125 (manufactured by Yasuhara Chemical Co., Ltd.), YS Polystar T80 (manufactured by Yasuhara Chemical Co., Ltd.), YS Polystar T160 (manufactured by Yasuhara Chemical Co., Ltd.), YS Polystar T130 (manufactured by Yasuhara Chemical Co., Ltd.), YS Polystar T100 (manufactured by Yasuhara Chemical Co., Ltd.), and Sylvares TP115 (manufactured by Arizona Chemical Co., Ltd.).

[0052] Since it acts as a plasticizer in the composition and exhibits tackiness, the softening point of the terpene phenol resin contained in the tackifier (E) is preferably 40°C or higher, and more preferably 50°C or higher. The softening point of the tackifier (E) containing terpene phenol resin and additives is preferably 40 to 160°C, and more preferably 60 to 140°C, from the viewpoint of the plastic deformability of the semi-cured product of this composition and the adhesive strength after heat curing.

[0053] The tackifier (E) may further contain other tackifiers to the extent that it achieves the effects of the present invention. Examples of other tackifiers include petroleum-based hydrocarbon resins such as aliphatic unsaturated hydrocarbon resins, aliphatic saturated hydrocarbon resins, alicyclic unsaturated hydrocarbon resins, alicyclic saturated hydrocarbon resins, and aromatic hydrocarbon resins; hydrogenated aromatic hydrocarbon resins, rosin ester resins, hydrogenated rosin ester resins, hydrogenated terpene phenol resins, terpene resins, hydrogenated terpene resins, aromatic hydrocarbon-modified terpene resins, coumarone-indene resins, phenol resins, xylene resins, and combinations thereof. For example, the above-mentioned petroleum-based hydrocarbon resin has excellent compatibility with terpene phenol resins and other components in this composition, and may be used in combination with tackifiers or to lower the softening point of the composition. When using petroleum-based hydrocarbon resin, its content is preferably 50 parts by mass or less, and more preferably 5 to 45 parts by mass, per 100 parts by mass of the total amount of tackifier (E). Furthermore, the total amount of other tackifiers excluding petroleum hydrocarbon resins is preferably 10 parts by mass or less, and more preferably 1 part by mass or less, out of 100 parts by mass of the total amount of tackifier (E).

[0054] The preferred content of the tackifier (E) is 20 to 50 parts by mass per 100 parts by mass of the curable composition.

[0055] <Optional addition ingredients> The curable composition may further contain other components to the extent that it achieves the effects of the present invention. Examples of such components include plasticizers, coupling agents, polymerization inhibitors, antioxidants, defoamers, pigments, fillers, chain transfer agents, light stabilizers, surface tension modifiers, leveling agents, UV absorbers, antifoaming agents, and solvents. The preferred content of these optional additives is 0.1 to 5 parts by mass per 100 parts by mass of the curable composition.

[0056] The method for preparing this curable composition is not particularly limited as long as it allows for the dispersion of a photopolymerization initiator (B), an epoxy resin (C), a thermosetting agent (D), a tackifier (E), and optional additives used as needed, in a monofunctional (meth)acrylate (A1) and a polyfunctional (meth)acrylate (A2), and can be mixed using known mixing methods.

[0057] (Uses of this curable composition) This curable composition can be used as a composition for forming a cured product on a substrate, and as an adhesive for bonding substrates together, and is preferably used as an adhesive. Furthermore, this curable composition can be used as an adhesive for bonding substrates together in a semi-cured state by photocuring.

[0058] The specific applications of this curable composition are not particularly limited, but it can be suitably used, for example, as an adhesive when assembling camera modules, hard disk drives, optical devices, motors, electronic components, etc., or as a sealing adhesive for optical devices.

[0059] [Semi-cured product] The semi-cured product of this disclosure is obtained by photocuring the curable composition of this disclosure. One example of a method for producing a semi-cured product is to irradiate the curable composition with energy rays. The above energy rays can be appropriately selected depending on the type of photopolymerization initiator (B). Specific examples include active energy rays such as visible light, ultraviolet light, X-rays, and electron beams, with ultraviolet light being preferred. As a light source for ultraviolet light, a light source that emits ultraviolet (UV) rays can be used. Examples of ultraviolet light sources include metal halide lamps, high-pressure mercury lamps, xenon lamps, mercury xenon lamps, halogen lamps, pulsed xenon lamps, and LEDs. The irradiation of energy rays involves an integrated energy ray intensity of 500-10,000 mJ / cm². 2 It is preferable to irradiate in such a manner. The integrated light intensity should be 1,000 to 8,000 mJ / cm². 2Preferably, the concentration is 1,000 to 6,000 mJ / cm². 2 It is preferable that this is the case.

[0060] [Substrate with semi-cured material] The substrate with a semi-cured material of this disclosure comprises the semi-cured material on the substrate. This substrate with a semi-cured material can be stored in this state and has excellent handling properties.

[0061] The above-mentioned base materials can be appropriately selected and used from a wide range of options depending on the application. Examples of substrate materials include amide-imide resins such as nylon and polyimide, heat-resistant resins such as epoxy resins, polyphenylene sulfide, and liquid crystal polymers, alloy inorganic materials such as aluminum alloys, magnesium alloys, and SUS, acetylcellulose resins such as triacetylcellulose, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, olefin resins such as polyethylene and polymethylpentene, acrylic resins, polyurethane resins, transparent resins such as polyethersulfone, polycarbonate, polysulfone, polyether, polyetherketone, acronitrile, methacrylonitrile, and cycloolefin copolymer (COP), as well as glass such as soda glass, potash glass, and lead glass, ceramics such as PLZT, and transparent inorganic materials such as quartz and fluorite.

[0062] Furthermore, a release-type substrate may be used as the base material. With a semi-cured substrate using a release-type substrate, for example, the semi-cured material can be easily attached to the surface of the desired adherend by peeling off the release-type substrate after the semi-cured material has been attached to the desired adherend.

[0063] A method for manufacturing a substrate with a semi-cured material can be, for example, by applying the curable composition to a desired substrate and irradiating the substrate with light. Alternatively, the curable composition may be irradiated with light to form a semi-cured material, and then the semi-cured material may be applied to the substrate. The method for forming the coating film can be appropriately selected from known coating and printing methods.

[0064] [Laminated structure] The laminate of this disclosure comprises, in this order, a cured product of the curable composition and a second substrate on a first substrate. The laminate exhibits excellent adhesive strength between the first substrate and the second substrate.

[0065] The first and second substrates can be appropriately selected from a wide range of options depending on the application, and examples include those similar to the substrates exemplified in the semi-cured substrate.

[0066] [Method for manufacturing laminates] The method for manufacturing the above-mentioned laminate is not particularly limited, but the following manufacturing method is preferred in terms of ease of manufacture and other factors. That is, the first method for manufacturing the laminate includes the step of placing the curable composition on a first substrate, The steps include: irradiating the curable composition with light to form a semi-cured product; The steps include placing a second substrate on the semi-cured material, The process includes the step of heating the semi-cured material while applying pressure to the second substrate in the direction of the first substrate. Furthermore, the second method for manufacturing the laminate includes the step of placing the curable composition on the first substrate, The steps include: irradiating the curable composition with light to form a semi-cured product; The steps include placing a second substrate on the semi-cured material, The steps include heating and melting the semi-cured material, The process includes a step of heating the semi-cured material at a higher temperature than the previous step to thermally cure it. The following describes each step in the manufacturing method of this laminate, with reference to Figure 1.

[0067] <Process (I)> First, a curable composition is prepared containing a monofunctional (meth)acrylate (A1), a polyfunctional (meth)acrylate (A2), a photopolymerization initiator (B), an epoxy resin (C), a thermosetting agent (D), a tackifier (E), and optional additives used as needed (Step (I)).

[0068] <Process (II)> Next, the curable composition prepared in step (I) above is applied to the first substrate to be bonded (step (II)). The method for forming the coating film can be appropriately selected from known coating and printing methods. Dispenser coating or screen printing is preferred because it allows for the formation of a patterned coating film and enables the creation of a thick film.

[0069] Dispenser application is a method of applying the curable composition using a device that dispenses a fixed amount of the curable composition. The dispensing method is not particularly limited and can be appropriately selected from, for example, an air pulse method, a mechanical method, a non-contact method, a plunger method, etc. As an example, in the case of an air pulse type dispenser, the curable composition is filled into a syringe and an air pulse is applied to dispense a fixed amount of the curable composition at a time, and applied in a predetermined pattern such as a dot pattern. Screen printing is a method of transferring a curable composition to a predetermined pattern by applying a curable composition to a screen having predetermined openings, placing the screen on the first substrate, and pressing the screen onto the first substrate using a squeegee.

[0070] The film thickness of the curable composition coating is not particularly limited. The material, size, and shape of the first substrate can be appropriately selected according to the application of the laminate being manufactured. The material of the adhesive surface of the substrate only needs to have heat resistance to the temperature during thermal curing, and examples include metals such as gold and copper, silicon, and inorganic ceramics.

[0071] <Process (III)> Next, the coating film is irradiated with light to partially cure the curable composition (step (III)). The energy rays used for irradiation are set to an integrated light dose of 500 to 10,000 mJ / cm², taking into consideration the content of monofunctional (meth)acrylate (A1) in the curable composition. 2 The irradiation can be directed arbitrarily within this range. In particular, the integrated light intensity is 1,000 to 8,000 mJ / cm². 2 Preferably, the concentration is 1,000 to 6,000 mJ / cm². 2 It is preferable that this is the case.

[0072] <Process (IV)> Next, the second substrate is placed on the semi-cured curable composition (step (IV)). The material, size, and shape of the second substrate may be appropriately selected according to the application of the laminate to be manufactured, similar to the first substrate. Alternatively, the first and second substrates may have different materials, sizes, and shapes.

[0073] <Process (V-1)> Next, the second substrate placed on the curable composition is pressed against the first substrate by applying pressure, and the semi-cured curable composition is heated (step (V-1)). By applying pressure, any steps or irregularities between the first and second substrates are filled in by the curable composition. Furthermore, by heating, the semi-cured curable composition is heat-cured, and the first and second substrates are bonded together via the cured curable composition. The pressure applied is not particularly limited, and the first substrate may be pressed towards the second substrate. The heating temperature can be arbitrarily set in the range of 70 to 120°C, taking into consideration the curing temperature of the epoxy resin (C), etc. The heating time can be arbitrarily set in the range of 10 minutes to 2 hours, taking into consideration the epoxy resin (C) content, etc.

[0074] <Process (V-2A)> However, following step (IV), heating may be performed without pressurization to melt the semi-cured curable composition between the first and second substrates (step (V-2A)). By melting the semi-cured curable composition, the melted curable composition fills in any steps or irregularities between the first and second substrates, thus filling the gaps. The heating temperature and heating time are not particularly limited, but they are such that the semi-cured curable composition melts but does not harden.

[0075] <Process (V-2B)> Following step (V-2A), the molten curable composition is heated (step (V-2B)). The heating temperature and heating time range are the same as in step (V-1), but the heating temperature in step (V-2B) is higher than the heating temperature in step (V-2A). Additionally, the second substrate may be optionally pressurized in the direction of the first substrate, or the first substrate in the direction of the second substrate.

[0076] According to the above-described method for manufacturing a laminate, a laminate can be obtained in which a first substrate and a second substrate are bonded together by the cured curable composition. This laminate exhibits excellent post-curing adhesion between the first substrate and the second substrate. [Examples]

[0077] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

[0078] [Example: Preparation of a curable composition] The components other than the thermosetting agent (D) were mixed according to the proportions (parts by mass) shown in Table 1, and the mixture was heated at 60°C for 30 minutes. The heated mixture was stirred using a rotary-type stirrer. After the composition returned to room temperature (approximately 25°C), the thermosetting agent (D) was added and the mixture was uniformly mixed using a rotary-type stirrer to prepare the curable compositions of the examples and comparative examples.

[0079] [evaluation] (1) Compatibility evaluation The resulting curable composition was left at 25°C for 24 hours, and the presence or absence of phase separation was visually confirmed. <Compatibility Evaluation Criteria> ○: Phase separation was not observed. ×: Phase separation was observed.

[0080] (2) Evaluation of the photocurability of the semi-cured product As shown in Figure 2(a), the obtained curable composition was applied to a 10 mm square × 2 mm thick plastic block (Kuraray Co., Ltd., polyamide LA121) at two diagonal points, with each point measuring 3.0 ± 0.5 mm in diameter. After application, ultraviolet light was applied using a metal halide lamp to an integrated light intensity of 1500 mJ / cm². 2 The curable composition was photocured by irradiating it to a certain degree. At that time, it was visually confirmed whether or not the curable composition had been photocured. <Criteria for evaluating photocurability> ○: The curable composition did not flow when contacted with a needle. ×: The curable composition flowed when it came into contact with the needle.

[0081] (3) Evaluation of retention strength after photocuring As shown in Figure 2(b), a laminate was created by pressing the plastic block coated with the curable composition onto a plastic plate (Kuraray Co., Ltd., polyamide LA121) with a 50 μm thick gap. Then, the plastic plate was inverted so that the plastic block coated with the curable composition was on the underside of the plastic plate, and it was checked whether the plastic block fell off or not. <Retention Power Evaluation Criteria> ○: The plastic block did not fall within 1 minute. ×: The plastic block fell within one minute.

[0082] (4) Evaluation of adhesive strength after heat curing The laminate prepared in (3) was heated in a constant temperature bath at 100°C for 60 minutes. After heating, the temperature of the laminate was confirmed to have returned to 25°C, and then the adhesive strength of the laminate was measured using a tensile and compression testing machine. <Adhesion strength evaluation criteria> ○: 0.8 N / mm 2 The above levels of intensity were observed. ×: 0.8N / mm 2 An intensity of less than the following was observed.

[0083] [Table 1]

[0084] [Table 2]

[0085] <Monofunctional (meth)acrylate (A1)> • Light Acrylate EC-A: Manufactured by Kyoeisha Chemical Co., Ltd. Ethoxydiethylene glycol acrylate Molecular weight 188 Boiling point 95℃ 5mmHg • Viscoat #197: Manufactured by Osaka Organic Chemical Industry Co., Ltd. Nonyl acrylate, molecular weight 198, melting point -34℃ • Viscoat #150D: Manufactured by Osaka Organic Chemical Industry Co., Ltd. Tetrahydrofurfuryl alcohol acrylic acid polymer ester. Molecular weight 150-550. Liquid at room temperature (25°C). • 4-HBA: Hydroxybutyl acrylate, manufactured by Osaka Organic Chemical Industry Co., Ltd. Molecular weight 144, melting point -112℃ NK Ester A-BZ: Manufactured by Shin-Nakamura Chemical Industry Co., Ltd. Benzyl acrylate, molecular weight 162, melting point 214-216℃ IBOA: Isobolonyl acrylate, manufactured by Nippon Shokubai Co., Ltd. Molecular weight 208, melting point <-35℃ • Viscoat #200: Manufactured by Osaka Organic Chemical Industry Co., Ltd. Cyclic trimethylolpropane formal acrylate, molecular weight 200, liquid at room temperature. • Light Acrylate POB-A: Manufactured by Kyoeisha Chemical Co., Ltd. 3-phenoxybenzyl acrylate Molecular weight 254 Liquid at room temperature <Polyfunctional (meth)acrylate (A2)> SA-1002N: Tricyclodecanedimethanol diacrylate, manufactured by Mitsubishi Chemical Corporation. Molecular weight: 304 • Viscoat #295: Manufactured by Osaka Organic Chemical Industry Co., Ltd. Trimethylolpropane triacrylate, molecular weight 296, melting point <-20℃ • UN9200A: Manufactured by Negami Kogyo Co., Ltd. Polycarbonate-based urethane acrylate (bifunctional), molecular weight 15,000 (oligomer-level molecular weight), liquid at room temperature. <Photopolymerization initiator (B)> Omnirad1173: Hydroxymethylphenylacetophenone, manufactured by IGM Resins, molecular weight 164 <Epoxy resin (C)> EXA-850CRP: Bisphenol A type epoxy resin manufactured by DIC Corporation. Epoxy equivalent weight: 170-175 g / eq. Liquid at room temperature. Viscosity: 3,500-5,500 mPa·s (25℃). EXA-830CRP: Bisphenol F type epoxy resin manufactured by DIC Corporation. Epoxy equivalent weight: 156-168 g / eq. Liquid at room temperature. Viscosity: 1,000-2,500 mPa·s (25℃). • EPOX-MK R1710: Bisphenol E type epoxy resin manufactured by Printec Co., Ltd. Epoxy equivalent weight 165 g / eq. Liquid at room temperature. Viscosity 2,000 mPa·s. jER YX8034: Manufactured by Mitsubishi Chemical Corporation. Hydrogenated bisphenol A epoxy resin. Epoxy equivalent weight 270 g / eq. Liquid at room temperature. Viscosity 280 mPa·s (25℃). HP-4032D: DIC Corporation Naphthalene-type epoxy resin. Epoxy equivalent weight 136-150 g / eq. Liquid or crystalline at room temperature. Viscosity 250-850 dPa·s (150℃). • Celoxide 2021P: Manufactured by Daicel Corporation. Alicyclic epoxy resin. Epoxy equivalent: 130 g / eq. Liquid at room temperature. Viscosity: 240 mPa·s (25℃). • N655-EXP-S: Cresol novolac type epoxy resin manufactured by DIC Corporation. Epoxy equivalent weight 196-206 g / eq. Solid at room temperature. Softening point 54-62°C. <Other thermosetting resins> • OXT-211: Manufactured by Toagosei Co., Ltd. 3-ethyl-3-phenoxymethyloxetane Molecular weight 192 Melting point <-20℃ Glass transition temperature 1℃ • OXT-121: Manufactured by Toagosei Co., Ltd. Xylylene bisoxetane, molecular weight 334, liquid at room temperature, glass transition temperature 94°C <Thermosetting agent (D)> • EH5030S: ADEKA-made polyamine-type thermosetting agent, melting point 70-80°C • CXC1612: KING Corporation Quaternary ammonium salt-based thermal initiator, melting point above 100°C. <Tackifier (E)> • YS Polystar K125: Manufactured by Yasuhara Chemical Co., Ltd. Terpene phenol resin. Softening point 125±5℃ • YS Polystar T80: Manufactured by Yasuhara Chemical Co., Ltd. Terpene phenol resin, softening point 80±5℃, contains petroleum hydrocarbon resin. • Clearon M125: Hydrogenated terpene resin manufactured by Yasuhara Chemical Co., Ltd. Softening point 125±5℃ • YS Resin CP: Manufactured by Yasuhara Chemical Co., Ltd. Camphenephenol resin. Liquid at room temperature. Viscosity of 1,000 mPa·s or less (at 25℃).

[0086] As shown in Tables 1 and 2, the curable compositions of Examples 1 to 13, each containing a monofunctional (meth)acrylate (A1) having an ether linkage, a linear aliphatic hydrocarbon group, or multiple ester links, a polyfunctional (meth)acrylate (A2), a photopolymerization initiator (B), an epoxy resin (C), a thermosetting agent (D), and a tackifier (E) containing a terpene phenol resin, all exhibited excellent compatibility, photocurability, post-photocuring retention, and post-thermosetting adhesion, demonstrating their suitability as adhesives.

Claims

1. A curable composition comprising a monofunctional (meth)acrylate (A1) containing a linear aliphatic hydrocarbon group which may have an ether bond and / or ester bond between carbon atoms and which may have an alicyclic ring which may have a heteroatom as a substituent; a polyfunctional (meth)acrylate (A2); a photopolymerization initiator (B); an epoxy resin (C); a thermosetting agent (D); and a tackifier (E) which contains a terpene phenol resin.

2. The curable composition according to claim 1, wherein the terpene phenol resin has a softening point of 50°C or higher.

3. The curable composition according to claim 1, wherein the polyfunctional (meth)acrylate (A2) has a molecular weight of 20,000 or less.

4. The curable composition according to claim 1, wherein the epoxy resin (C) has an aromatic ring or an alicyclic ring.

5. The curable composition according to claim 1, wherein the photopolymerization initiator (B) has a carbonyl group.

6. The curable composition according to claim 1, wherein the thermosetting agent (D) comprises an amine or a quaternary ammonium salt.

7. A semi-cured product of a curable composition according to any one of claims 1 to 6.

8. A substrate comprising the semi-cured material described in claim 7, Substrate with semi-cured material.

9. A first substrate is provided with a cured product of a curable composition according to any one of claims 1 to 6, and a second substrate, in this order. Laminated structure.

10. The laminate according to claim 9, wherein the first substrate and / or the second substrate have an uneven shape.

11. The steps include placing the curable composition according to any one of claims 1 to 6 on a first substrate, The steps include: irradiating the curable composition with light to form a semi-cured product; The steps include placing a second substrate on the semi-cured material, The process includes the step of heating the semi-cured material while applying pressure to the second substrate in the direction of the first substrate, A method for manufacturing laminates.

12. The steps include placing the curable composition according to any one of claims 1 to 6 on a first substrate, The steps include: irradiating the curable composition with light to form a semi-cured product; The steps include placing a second substrate on the semi-cured material, The steps include heating and melting the semi-cured material, The process includes a step of heating the semi-cured material at a higher temperature than the previous step to cure it. A method for manufacturing laminates.

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