Curable components, semi-curable materials, substrates with semi-curable materials, laminates, and methods for manufacturing laminates.

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 this disclosure contains a monofunctional (meth)acrylate (A1) having one or more selected from ether bonds, aromatic rings, and hydroxyl groups, a polyfunctional (meth)acrylate (A2) with a molecular weight of 500 or less, a photopolymerization initiator (B), a solid epoxy resin (C), and a thermosetting agent (D), wherein the content of epoxy resin (C) is 35 to 85 parts by mass in a total of 100 parts by mass of monofunctional (meth)acrylate (A1) and epoxy resin (C).

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 a laminate. [Background technology]

[0002] Adhesives containing photocurable and thermosetting components are known. For example, Patent Document 1 discloses a semiconductor adhesive that can be B-staged in a short time by light irradiation, comprising a specific amount of radical polymerizable monomer, a specific photoradical generator, a thermosetting resin, and a specific thermosetting agent. Patent Document 1 also discloses a method of using the adhesive, in which the adhesive is applied to a substrate, partially cured (B-staged) by light irradiation, and then a semiconductor chip is mounted on the substrate and bonded by heat and pressure. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2007-258508 [Overview of the project] [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 monofunctional (meth)acrylate (A1) having one or more selected from ether linkages, aromatic rings, and hydroxyl groups; a polyfunctional (meth)acrylate (A2) with a molecular weight of 500 or less; a photopolymerization initiator (B); a solid epoxy resin (C); and a thermosetting agent (D). In a total of 100 parts by mass of the monofunctional (meth)acrylate (A1) and the epoxy resin (C), the content of the epoxy resin (C) is 35 to 85 parts by mass. Curable composition. [2] The curable composition according to [1], comprising 1.5 to 8 parts by mass of the polyfunctional (meth)acrylate (A2) per 100 parts by mass of the monofunctional (meth)acrylate (A1). [3] After photocuring, the storage modulus at 25°C is 1.0 kPa or higher. The curable composition described in [1] or [2]. [4] After further heat curing, the storage modulus at 25°C is 1.0 MPa or higher. [3] The curable composition described above. [5] A semi-cured product of any of the curable compositions described in [1] to [4]. [6] The semi-cured product according to [5], wherein the storage modulus at 25°C is 1.0 kPa or more. [7] A substrate comprising the semi-cured material described in [5], Substrate with semi-cured material. [8] A first substrate is provided with a cured product of any of the curable compositions described in [1] to [4] and a second substrate in this order. Laminated structure. [9] The laminate according to [8], wherein the first substrate and / or the second substrate has an uneven shape.

[10] The step of placing the curable composition described in any of [1] to [4] 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.

[11] The step of placing the curable composition described in any one of [1] to [4] on a first substrate, The steps include: irradiating the curable composition with light to form a semi-cured product; 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 including: A method for manufacturing a laminate.

Advantages of the Invention

[0006] According to the present invention, there can be provided 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 including 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 the present 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.

Modes 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 including 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. 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. Also, "~" indicating a numerical range includes its lower limit value and upper limit value unless otherwise specified.

[0009] [Curable Composition] The curable composition of this embodiment contains a monofunctional (meth)acrylate (A1) having at least one selected from an ether bond, an aromatic ring, and a hydroxy group, a polyfunctional (meth)acrylate (A2) having a molecular weight of 500 or less, a photopolymerization initiator (B), a solid epoxy resin (C), and a thermosetting agent (D). In a total of 100 parts by mass of the monofunctional (meth)acrylate (A1) and the epoxy resin (C), the content of the epoxy resin (C) is 35 to 85 parts by mass.

[0010] In the curable composition of this embodiment, the above-mentioned specific monofunctional (meth)acrylate (A1) and the solid epoxy resin (C) are compatible, so the uniformity of the composition is maintained even when it is extended to follow the surface shape of the adherend surface. By using the polyfunctional (meth)acrylate (A2) having a relatively small molecular weight in combination, the curable composition of this embodiment achieves both the plastic deformability and adhesiveness in the semi-cured state of the composition. Further, the curable composition of this embodiment contains the solid epoxy resin (C) in the above-mentioned specific amount. The solid epoxy resin exhibits the effect as a plasticizer in the semi-cured state, and by containing it in the above-mentioned specific amount, both the flexibility (plastic deformability) in the semi-cured state and the curing strength after heating are achieved. From these facts, the curable composition of this embodiment has adhesiveness and plastic deformability in the semi-cured state, and becomes a curable composition having excellent strength after thermosetting, and can be suitably used as, for example, an adhesive.

[0011] The curable composition of this embodiment contains at least a monofunctional (meth)acrylate (A1), a polyfunctional (meth)acrylate (A2), a photopolymerization initiator (B), a solid epoxy resin (C), and a thermosetting agent (D), and may further contain other components. Hereinafter, each component that can be included in this composition will be described.

[0012] <Monofunctional (meth)acrylate (A1)> This curable composition contains (meth)acrylate (A) as a photocurable component. Monofunctional (meth)acrylate (A1) has one or more selected from ether bonds, aromatic rings, and hydroxyl groups in its molecule, and one (meth)acryloyl group as a functional group. By using a monofunctional (meth)acrylate (A1), the compatibility between the (meth)acrylate and the solid epoxy resin (C) is improved. Examples of aromatic rings include carboelectric rings such as benzene, naphthalene, and anthracene; and heterocyclic rings such as furan, pyrrole, pyridine, pyrazine, quinoline, isoquinoline, and carbazole. Among these, carboelectric rings are preferred, and benzene rings are more preferred.

[0013] 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 of the composition.

[0014] The molecular weight of the monofunctional (meth)acrylate (A1) is preferably 1000 or less, more preferably 80 to 800, and even more preferably 100 to 500, from the viewpoint of the plastic deformability, tackiness, and compatibility with the solid epoxy resin (C) in the semi-cured state of the composition.

[0015] The viscosity of the monofunctional (meth)acrylate (A1) at 25°C is preferably 0.1 to 100 mPa·s, from the viewpoint of compositional uniformity and applicability.

[0016] A specific example of a monofunctional (meth)acrylate (A1) is: (Meth)acrylates having ether bonds, 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; (Meth)acrylates having aromatic rings, such as phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, ethoxylated ortho-phenylphenol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, and benzyl (meth)acrylate; Examples include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; and (meth)acrylates having a hydroxyl group such as 2-(meth)acryloyloxyethyl-2-hydroxypropyl phthalate, 2-hydroxy-3-(meth)acryloyloxypropyl acrylate, caprolactone-modified 2-hydroxyethyl (meth)acrylate, and cyclohexanedimethanol mono(meth)acrylate. Monofunctional (meth)acrylate (A1) can be used alone or in combination of two or more types.

[0017] 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.), benzyl acrylate (NK Ester A-BZ, manufactured by Shin Nakamura Chemical Industry Co., Ltd.), and hydroxyl butyl acrylate (4-HBA, manufactured by Osaka Organic Chemical Industry Co., Ltd.).

[0018] <Polyfunctional (meth)acrylate (A2) with a molecular weight of 500 or less> A polyfunctional (meth)acrylate (A2) is a compound with a molecular weight of 500 or less and having two or more (meth)acryloyl groups in its molecule. By including a relatively low molecular weight 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.

[0019] 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.

[0020] The molecular weight of the polyfunctional (meth)acrylate (A2) is preferably 500 or less, more preferably 140 to 450, and even more preferably 180 to 400, from the viewpoint of the plastic deformability, tackiness, and compatibility with the solid epoxy resin (C) in the semi-cured state of the composition.

[0021] 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; Examples include trimethylolpropane tri(meth)acrylate, glycerol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, and other trifunctional acrylates. Polyfunctional (meth)acrylates (A2) can be used individually or in combination of two or more types.

[0022] 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) and trimethylolpropane triacrylate (Viscote 295, manufactured by Osaka Organic Chemical Industry Co., Ltd.).

[0023] The ratio of monofunctional (meth)acrylate (A1) to polyfunctional (meth)acrylate (A2) can be adjusted as appropriate. In order to achieve both plastic deformability and tackiness in the semi-cured state of the composition, the content of the polyfunctional (meth)acrylate (A2) is preferably 1.5 to 8 parts by mass, and more preferably 1.6 to 7.5 parts by mass, per 100 parts by mass of the monofunctional (meth)acrylate (A1).

[0024] <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 that do not have ether bonds, aromatic rings, or hydroxyl groups, and polyfunctional (meth)acrylates with a molecular weight exceeding 500. The content of other (meth)acrylates 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).

[0025] <Photopolymerization initiator (B)> This curable composition contains a photopolymerization initiator 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] The photopolymerization initiator (B) is preferably a carbonyl-based photopolymerization initiator from the viewpoint of sensitivity, and among these, hydroxymethylphenylacetophenone is preferred.

[0031] The photopolymerization initiator (B) can be a commercially available product and can be used alone or in combination of two or more types. From the viewpoint of curability and the strength of the cured composition, the content ratio 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).

[0032] <Solid epoxy resin (C)> This curable composition contains a solid epoxy resin (C) as a thermosetting component. Here, "solid" means that, before mixing with the monofunctional (meth)acrylate (A1), it is solid (crystalline), glassy, ​​or rubbery at least 25°C and 1 atm. In this composition, the epoxy resin (C) may be dissolved in the monofunctional (meth)acrylate (A1) or dispersed. The solid epoxy resin (C) also functions as a plasticizer in the composition, achieving both flexibility (plastic deformability) in the semi-cured state and curing strength after heating.

[0033] 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.

[0034] Furthermore, the epoxy equivalent of epoxy resin (C) is preferably 100 to 280 g / eq, more preferably 120 to 250 g / eq, and even more preferably 150 to 220 g / eq, from the viewpoint of film strength after heat curing.

[0035] Specific examples of epoxy resin (C) include: Examples of epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol E 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. Among these, cresol novolac type epoxy resins are preferred from the viewpoint of storage modulus and heat resistance of the thermoset curable composition.

[0036] Commercially available epoxy resin (C) can be used, and one type can be used alone or two or more types can be used in combination. From the viewpoint of curability and the strength of the composition after curing, the content of epoxy resin (C) is preferably 35 to 85 parts by mass, and more preferably 38 to 82 parts by mass, out of 100 parts by mass of the total of monofunctional (meth)acrylate (A1) and epoxy resin (C).

[0037] <Other epoxy resins> This composition may contain other epoxy resins to the extent that it achieves the effects of the present invention. Examples of other epoxy resins include epoxy resins that are liquid at 25°C. The content ratio of the other epoxy resin is preferably 150 parts by mass or less, and more preferably 100 parts by mass or less, per 100 parts by mass of epoxy resin (C).

[0038] <Thermosetting agent (D)> The thermosetting agent (D) can be appropriately selected from known epoxy curing agents. Examples of epoxy curing agents (D) include amine compounds, imidazole compounds, acid anhydride compounds, organophosphinic acid compounds, phenolic compounds, hydrazide compounds, and carbazide compounds. Alternatively, a thermoacid generator (cationic polymerization initiator) may be used as the thermosetting agent (D).

[0039] 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.

[0040] 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.

[0041] 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).

[0042] <Optional addition ingredients> The curable composition may further contain other components to the extent that it exhibits the effects of the present invention. Examples of such components include plasticizers, coupling agents, polymerization inhibitors, tackifiers, antioxidants, defoamers, pigments, fillers, chain transfer agents, light stabilizers, surface tension modifiers, leveling agents, UV absorbers, antifoaming agents, and solvents.

[0043] Examples of tackifiers include aliphatic unsaturated hydrocarbon resins, aliphatic saturated hydrocarbon resins, alicyclic unsaturated hydrocarbon resins, alicyclic saturated hydrocarbon resins, aromatic hydrocarbon resins, hydrogenated aromatic hydrocarbon resins, rosin ester resins, hydrogenated rosin ester resins, terpene phenol 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. Among these, terpene phenol resins are preferred.

[0044] When using a tackifier, the preferred content of the tackifier is 20 to 50 parts by mass per 100 parts by mass of the curable composition.

[0045] 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), and any 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.

[0046] (Storage modulus) The storage modulus at 25°C of the semi-cured product obtained from this curable composition is preferably 1.0 kPa or higher, more preferably 1.0 to 50 kPa, and even more preferably 2.0 to 20 kPa. Having the storage modulus of the semi-cured film within this range allows for both plastic deformability and tackiness. The storage modulus at 25°C of the cured product obtained from this curable composition is preferably 1.0 MPa or higher, more preferably 1.0 to 800 MPa, and even more preferably 2.0 to 400 MPa. Having the storage modulus of the cured film within this range results in excellent adhesive strength.

[0047] In this disclosure, the storage modulus is a value measured by the following method. <<Create Sample>> The semi-cured product is obtained by applying UV irradiance of 500 mW / cm² to this curable composition. 2 The sample obtained by irradiating with ultraviolet light for 12 seconds is used. For example, the UV light is obtained by using a mercury xenon lamp (L9588-01A) manufactured by Hamamatsu Photonics as the light source, and the light transmitted through a wavelength cut filter (A9616-03) is used. The cured product is obtained by heating the semi-cured product to 120°C at a heating rate of 20°C / min, holding it for 30 minutes, and then cooling it to 25°C at a cooling rate of 20°C / min. <<Measurement Conditions>> The storage modulus of the sample at 1 Hz is measured using a rheometer. For example, a rheometer such as the MCR302 manufactured by Anton Pal can be used.

[0048] Here, the storage modulus of the curable composition after photocuring tends to increase by methods such as increasing the content of monofunctional (meth)acrylate (A1) or polyfunctional (meth)acrylate (A2) in the curable composition. It also tends to increase by using epoxy resin (C) with a high softening point. By using these methods with reference to the above-described configurations, the storage modulus of the curable composition after photocuring can be adjusted.

[0049] (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.

[0050] 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.

[0051] [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. 2 Preferably, the concentration is 1,000 to 6,000 mJ / cm². 2 It is preferable that this is the case.

[0052] The storage modulus of the semi-cured material at 25°C is preferably 1.0 kPa or higher. A storage modulus of 1.0 kPa or higher allows the semi-cured material to form a plastically deformable adhesive layer, which penetrates into steps on the substrate surface and exhibits an anchoring effect.

[0053] [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 is easy to handle.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] [Laminated structure] The laminate of this disclosure comprises, in this order, a cured product of a curable composition according to any one of claims 1 to 4, and a second substrate on a first substrate. The laminate exhibits excellent adhesive strength between the first substrate and the second substrate.

[0058] 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.

[0059] [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 cure it. A method for manufacturing laminates. The following describes each step in the manufacturing method of this laminate, with reference to Figure 1.

[0060] <Process (I)> First, a curable composition is prepared containing a monofunctional (meth)acrylate (A1), a polyfunctional (meth)acrylate (A2), a photopolymerization initiator (B), a solid epoxy resin (C), a thermosetting agent (D), and optional additives used as needed.

[0061] <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.

[0062] 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.

[0063] 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.

[0064] <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.

[0065] <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.

[0066] <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.

[0067] <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.

[0068] <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.

[0069] 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]

[0070] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

[0071] [Example: Preparation of a curable composition] The components other than the thermosetting agent 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.

[0072] [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> ○: No phase separation was observed. ×: Phase separation was observed.

[0073] (2) Photo-curability Evaluation of Semi-cured Product As shown in Fig. 2(a), the obtained curable composition was applied at two diagonal points on a plastic block (manufactured by Kuraray Co., Ltd., polyamide LA121) with a size of 10 mm square × 2 mm thickness, with each point having a size of 3.0 ± 0.5 mmφ. After application, using a metal halide lamp, ultraviolet light was irradiated so that the integrated light quantity was 1500 mJ / cm 2 to photocure the curable composition. At that time, it was visually confirmed whether the curable composition was photocured. <Photo-curability Evaluation Criteria> ○: When the curable composition was contacted with a needle, it did not flow. ×: When the curable composition was contacted with a needle, it flowed.

[0074] (3) Retaining Force Evaluation after Photo-curing As shown in Fig. 2(b), the plastic block with the curable composition was pressed against a plastic plate (manufactured by Kuraray Co., Ltd., polyamide LA121) with a 50-μm-thick gap provided to prepare a laminate. Then, the plastic plate was inverted up and down so that the plastic block with the curable composition was positioned on the lower side of the plastic plate, and it was confirmed whether the plastic block fell. <Retaining Force Evaluation Criteria> ○: The plastic block did not fall within 1 minute. ×: The plastic block fell within 1 minute.

[0075] (4) Adhesive Force Evaluation after Thermal Curing The laminate prepared in (3) was heated at 100°C for 60 minutes using a thermostatic bath. After heating, after confirming that the temperature of the laminate had returned to 25°C, the adhesive strength of the laminate was measured using a tensile-compression testing machine. <Adhesive Force Evaluation Criteria> ○: A strength of 1.0 N / mm 2 or higher was exhibited. ×: 1.0N / mm 2 An intensity of less than the following was observed.

[0076] (5) Measurement of the storage modulus Each prepared curable composition was irradiated with light from a mercury xenon lamp (Hamamatsu Photonics, L9588-01A) with wavelengths of 280-400 nm extracted using a wavelength cut filter (Hamamatsu Photonics, A9616-03). The integrated light intensity was 6000 mJ / cm². 2 The 1Hz storage modulus of the curable composition, after irradiation and subsequent temperature reduction to 25°C, was measured using a rheometer (Anton Paar, MCR302). Next, the curable composition after light irradiation was heated to 120°C at a heating rate of 20°C / min and held at 120°C for 30 minutes. After that, it was cooled at a cooling rate of 20°C / min, and the 1Hz storage modulus at which the temperature had decreased to 25°C was measured using the rheometer.

[0077] [Table 1]

[0078] <Monofunctional (meth)acrylate (A1)> EC-A: Manufactured by Kyoeisha Chemical Co., Ltd. Ethoxydiethylene glycol acrylate, molecular weight 188, boiling point 95℃, 5mmHg A-BZ: Benzyl acrylate, manufactured by Shin-Nakamura Chemical Industry Co., Ltd. Molecular weight 162, melting point 214-216℃ • 4-HBA: Hydroxybutyl acrylate, manufactured by Osaka Organic Chemical Industry Co., Ltd. Molecular weight 144, melting point -112℃ • Viscoat #197: Manufactured by Osaka Organic Chemical Industry Co., Ltd. Nonyl acrylate, molecular weight 198, melting point -34℃ IBOA: Isobolonyl acrylate, manufactured by Nippon Shokubai Co., Ltd. Molecular weight 208, melting point <-35℃ <Polyfunctional (meth)acrylate (A2)> SA-1002N: Tricyclodecanedimethanol diacrylate, manufactured by Mitsubishi Chemical Corporation. Molecular weight: 304 <Photopolymerization initiator (B)> Omnirad1173: Hydroxymethylphenylacetophenone, manufactured by IGM Resins, molecular weight 164 <Epoxy resin (C)> • N655-EXP-S: Cresol novolac type epoxy resin manufactured by DIC Corporation. Epoxy equivalent weight 196-206 g / eq. Softening point 54-62°C. EXA-850CRP: Bisphenol A type epoxy resin manufactured by DIC Corporation. Epoxy equivalent weight: 170-175 g / eq <Thermosetting agent (D)> • CXC1612: KING Corporation Quaternary ammonium salt-based thermal initiator, melting point above 100°C. • EH5030S: ADEKA-made polyamine-type thermosetting agent, melting point 70-80°C <Adhesion agent> • K125: Terpene phenol resin manufactured by Yasuhara Chemical Co., Ltd. Softening point 125±5℃

[0079] As shown in Table 1, the curable compositions of Examples 1 to 9, each containing a monofunctional (meth)acrylate (A1) having one or more selected from ether bonds, aromatic rings, and hydroxyl groups, a polyfunctional (meth)acrylate (A2) with a molecular weight of 500 or less, a photopolymerization initiator (B), a solid epoxy resin (C), and a thermosetting agent (D), wherein the epoxy resin (C) content is 35 to 85 parts by mass in a total of 100 parts by mass of monofunctional (meth)acrylate (A1) and epoxy resin (C), all exhibited excellent compatibility, photocurability, retention strength after photocuring, and adhesive strength after thermocuring, demonstrating suitability as adhesives.

Claims

1. It contains a monofunctional (meth)acrylate (A1) having one or more selected from ether bonds, aromatic rings, and hydroxyl groups, a polyfunctional (meth)acrylate (A2) with a molecular weight of 500 or less, a photopolymerization initiator (B), a solid epoxy resin (C), and a thermosetting agent (D). In a total of 100 parts by mass of the monofunctional (meth)acrylate (A1) and the epoxy resin (C), the content of the epoxy resin (C) is 35 to 85 parts by mass. Curable composition.

2. The curable composition according to claim 1, comprising 1.5 to 8 parts by mass of the polyfunctional (meth)acrylate (A2) per 100 parts by mass of the monofunctional (meth)acrylate (A1).

3. After photocuring, the storage modulus at 25°C is 1.0 kPa or higher. The curable composition according to claim 1.

4. Furthermore, after thermal curing, the storage modulus at 25°C is 1.0 MPa or higher. The curable composition according to claim 3.

5. A semi-cured product of a curable composition according to any one of claims 1 to 4.

6. The semi-cured product according to claim 5, wherein the storage modulus at 25°C is 1.0 kPa or more.

7. A substrate comprising the semi-cured material according to claim 5, Substrate with semi-cured material.

8. A first substrate is provided with a cured product of a curable composition according to any one of claims 1 to 4, and a second substrate, in this order. Laminated structure.

9. The laminate according to claim 8, wherein the first substrate and / or the second substrate have an uneven shape.

10. The steps include placing the curable composition according to any one of claims 1 to 4 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.

11. The steps include placing the curable composition according to any one of claims 1 to 4 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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