Hardening components

Abstract

To provide a curable composition excellent in electrical insulation properties.SOLUTION: The curable composition according to one embodiment of the present invention contains: a (meth)acrylic polymer (A); an epoxy compound and / or an oxetane compound (B); a photoradical polymerization initiator (C); and an epoxy curing agent (D). The weight ratio of the (meth)acrylic polymer (A) to the epoxy compound and / or the oxetane compound (B) is (1:99)-(50:50). The (meth)acrylic polymer (A) has a molecular weight distribution (Mw / Mn) of 1.8 or less, the total of bromine element and potassium element contained in the polymer is 0 ppm or more and 25 ppm or less, and the polymer has 1.0 or more groups represented by "-OC(O)C(R1)=CH2" per molecule. In the formula, R1 represents a hydrogen atom or a C1-20 organic group.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a curable composition. [Background technology]

[0002] Curable compositions containing a (meth)acrylic polymer and an epoxy compound are known as prior art. Patent Document 1 describes a method for purifying a vinyl polymer produced by atom transfer radical polymerization of a vinyl monomer. Patent Document 2 describes a curable composition containing, as essential components, a vinyl polymer having a specific terminal structure produced by living radical polymerization of a (meth)acrylic monomer using a copper complex as a catalyst, an epoxy compound and / or an oxetane compound, a photoradical polymerization initiator, a photocationic polymerization initiator, and a compound having an epoxy group and a (meth)acryloyl group in the molecule. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-155846 [Patent Document 2] International Publication No. 2012 / 020545 [Patent Document 3] International Publication No. 2005 / 092981 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above-mentioned conventional techniques have room for further improvement in terms of realizing a curable composition with excellent electrical insulating properties.

[0005] An object of one aspect of the present invention is to provide a curable composition having excellent electrical insulating properties. [Means for solving the problem]

[0006] The curable composition according to one embodiment of the present invention comprises: a (meth)acrylic polymer (A); an epoxy compound and / or an oxetane compound (B); a photoradical polymerization initiator (C); an epoxy curing agent (D); Contains the weight ratio of the (meth)acrylic polymer (A) to the epoxy compound and / or oxetane compound (B) is (1:99) to (50:50); The (meth)acrylic polymer (A) is The molecular weight distribution (Mw / Mn) is 1.8 or less, The total amount of bromine and potassium contained in the polymer is 0 ppm or more and 25 ppm or less, and It has 1.0 or more (meth)acryloyl functional groups represented by the following general formula (a) per molecule. -OC(O)C(R 1 )=CH2...General formula (a) (In the formula, R 1 represents a hydrogen atom or an organic group having 1 to 20 carbon atoms). [Effects of the Invention]

[0007] According to one aspect of the present invention, there is provided a curable composition having excellent electrical insulation properties. DETAILED DESCRIPTION OF THE INVENTION

[0008] One embodiment of the present invention will be described below, but the present invention is not limited thereto. In this specification, unless otherwise specified, "A to B" representing a numerical range means "A or more and B or less." In this specification, "(meth)acrylic" means acrylic and / or methacrylic.

[0009] [1. (Meth)acrylic polymer (A)] The curable composition according to one embodiment of the present invention contains a (meth)acrylic polymer (A). The (meth)acrylic polymer (A) may be used alone or in combination of two or more types.

[0010] [1.1. Main chain of (meth)acrylic polymer] The (meth)acrylic monomer constituting the main chain of the (meth)acrylic polymer (A) is not particularly limited, and examples of the (meth)acrylic monomer include (meth)acrylic acid and (meth)acrylic acid esters. Examples of the (meth)acrylic acid ester include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, phenyl (meth)acrylate, toluyl (meth)acrylate, benzyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl ... hydroxypropyl, stearyl (meth)acrylate, glycidyl (meth)acrylate, 2-aminoethyl (meth)acrylate, γ-(methacryloyloxypropyl)trimethoxysilane, ethylene oxide adduct of (meth)acrylic acid, trifluoromethyl (meth)acrylate, 2-trifluoromethylethyl (meth)acrylate, 2-perfluoroethylethyl (meth)acrylate, 2-perfluoroethyl-2-perfluorobutylethyl (meth)acrylate, 2-perfluoroethyl (meth)acrylate, perfluoromethyl (meth)acrylate, diperfluoromethylmethyl (meth)acrylate, 2-perfluoromethyl-2-perfluoroethylmethyl (meth)acrylate, 2-perfluorohexylethyl (meth)acrylate, 2-perfluorodecylethyl (meth)acrylate, and 2-perfluorohexadecylethyl (meth)acrylate.

[0011] From the viewpoint of the physical properties of the resulting (meth)acrylic polymer (A), among these monomers, acrylic acid esters and methacrylic acid esters are preferred, acrylic acid esters are more preferred, and one or more selected from the group consisting of n-butyl acrylate, ethyl acrylate, and 2-methoxyethyl acrylate are even more preferred.

[0012] The (meth)acrylic polymer (A) may be composed of units derived from only one of these monomers, or may be composed of units derived from two or more monomers. The (meth)acrylic polymer (A) may be a copolymer of units derived from the above-mentioned preferred monomers and units derived from other monomers. In this case, the proportion of units derived from the preferred monomers in the (meth)acrylic polymer (A) is preferably 20% by weight or more, more preferably 50% by weight or more, and even more preferably 70% by weight or more.

[0013] [1.2. (Meth)acryloyl Functional Group in (Meth)acrylic Polymer (A)] The (meth)acrylic polymer (A) has 1.0 or more (meth)acryloyl functional groups represented by the following general formula (a) per molecule: 1 represents a hydrogen atom or an organic group having 1 to 20 carbon atoms. The (meth)acrylic polymer (A) has a (meth)acryloyl substituent and is therefore cured by irradiation with light. -OC(O)C(R 1 )=CH2...General formula (a)

[0014] The (meth)acryloyl functional group represented by general formula (a) may be located in the middle of the main chain of the (meth)acrylic polymer (A) or at the end of the main chain. From the viewpoint of the rubber elasticity to be obtained, the (meth)acryloyl functional group is preferably located at the end of the main chain.

[0015] In general formula (a), R 1 Examples of structures include -H, -CH3, -CH2CH3, -(CH2)n Examples include —CH3 (n is an integer of 2 to 19), —C6H5 (phenyl group), —CH2OH, and —CN. From the viewpoint of the reactivity of the (meth)acryloyl functional group, R 1 is preferably —H or —CH 3 .

[0016] The number of (meth)acryloyl functional groups contained in the (meth)acrylic polymer (A) is preferably 1.2 or more, more preferably 1.5 or more, and even more preferably 1.8 or more per molecule. The upper limit of the number of (meth)acryloyl functional groups contained in the (meth)acrylic polymer (A) may be, for example, 2.0 or less, 2.5 or less, or 3.0 or less per molecule.

[0017] [1.3. Molecular Weight Distribution of (Meth)acrylic Polymer (A)] The molecular weight distribution of the (meth)acrylic polymer (A) is 1.8 or less. In this specification, the molecular weight distribution refers to the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn). The weight average molecular weight and the number average molecular weight are measured by gel permeation chromatography (GPC). In one embodiment, the mobile phase used in the GPC measurement is chloroform or tetrahydrofuran. In one embodiment, the column used in the GPC measurement is a polystyrene gel column. The molecular weight value is determined as a polystyrene equivalent value.

[0018] The number average molecular weight of the (meth)acrylic polymer (A) is not particularly limited. The lower limit of the number average molecular weight is preferably 500 or more, more preferably 3,000 or more, even more preferably 5,000 or more, and most preferably 8,000 or more. The upper limit of the number average molecular weight is preferably 1,000,000 or less, more preferably 100,000 or less, even more preferably 80,000 or less, and most preferably 50,000 or less. If the number average molecular weight is too low, the desired properties of the (meth)acrylic polymer (A), such as tensile properties, tend to be less readily exhibited. If the number average molecular weight is too high, the polymer tends to be difficult to handle.

[0019] The molecular weight distribution of the (meth)acrylic polymer (A) is preferably 1.7 or less, more preferably 1.6 or less, even more preferably 1.5 or less, particularly preferably 1.4 or less, and most preferably 1.3 or less. The theoretical lower limit of the molecular weight distribution is 1.

[0020] [1.4. Ionic elements contained in (meth)acrylic polymer (A)] The (meth)acrylic polymer (A) has a reduced content of ionic elements. In this specification, the ionic elements refer to bromine and potassium. These ionic elements are basically incorporated during the synthesis of the main chain of the (meth)acrylic polymer (A). However, potassium is also incorporated during the introduction of functional groups.

[0021] The total amount of bromine and potassium contained in the (meth)acrylic polymer (A) is 25 ppm or less. From the viewpoint of electrical insulation, the total amount of bromine and potassium contained in the (meth)acrylic polymer (A) is preferably 20 ppm or less, more preferably 15 ppm or less, and even more preferably 10 ppm or less. Since bromine and potassium are inevitably contained during the synthesis of the (meth)acrylic polymer (A), the lower limit of the total content of these elements is greater than 0 ppm. This lower limit may be, for example, 0.1 ppm or 0.5 ppm. When the total amount of bromine and potassium is within the above range, the resulting cured product exhibits good electrical insulation.

[0022] Between elemental bromine and elemental potassium, elemental bromine tends to be contained in a larger amount in the (meth)acrylic polymer (A). Therefore, by reducing the amount of elemental bromine contained in the (meth)acrylic polymer (A), the amount of ionic elements contained in the (meth)acrylic polymer (A) can be efficiently reduced. The amount of elemental bromine contained in the (meth)acrylic polymer (A) is preferably 15 ppm or less, more preferably 10 ppm or less, and even more preferably 5 ppm or less. The lower limit may be, for example, 0.1 ppm or 0.5 ppm.

[0023] The content of ionic elements is measured by inductively coupled plasma mass spectrometry (ICP-MS).

[0024] In order to reduce the ionic element content of the (meth)acrylic polymer (A), for example, it is preferable to provide a purification step in the production process of the (meth)acrylic polymer (A). Examples of substances to be removed in the purification step include solvents (such as polymerization solvents) and insoluble components (such as polymerization catalysts). Specific examples of treatments in the purification step include liquid-liquid extraction using water and adsorption treatment using an adsorbent. To improve purification efficiency, a heat treatment may be performed in the purification step.

[0025] Another example of a method for reducing the ionic element content of the (meth)acrylic polymer (A) is chemical modification, specifically, a method in which a functional group is introduced to eliminate bromine groups contained in the polymer molecule.

[0026] For more detailed explanations regarding the purification process, see, for example, paragraphs

[0040] to

[0066] of JP-A No. 2004-002835 and paragraphs

[0117] to

[0143] of JP-A No. 2013-241541.

[0027] Specific examples of preferred production methods for reducing the ionic element content of the (meth)acrylic resin (A) include a method in which adsorption-filtration purification described in paragraphs

[0040] to

[0066] of JP 2004-002835 A is carried out before the step of introducing a (meth)acryloyl-based functional group, and water purification described in paragraphs

[0117] to

[0143] of JP 2013-241541 A is carried out after the step of introducing a (meth)acryloyl-based functional group. The production method will be described in more detail in the production examples described below.

[0028] 2. Method for producing (meth)acrylic polymer (A) [2.1. Method for manufacturing the main chain] The molecular weight distribution (Mw / Mn) of the (meth)acrylic polymer (A) is 1.8 or less. In order to achieve such a narrow molecular weight distribution, it is preferable to produce the (meth)acrylic polymer (A) by living polymerization. Examples of living polymerization include living radical polymerization, living anionic polymerization, and living cationic polymerization. From the viewpoints of raw material management, facility design, and the production process, living radical polymerization is preferred. Examples of living radical polymerization include ATRP (atom transfer radical polymerization), ARGET, ICAR, SET-LRP, RAFT, and NMP. From the viewpoints of raw material procurement and ease of purification, ATRP and ARGET are preferred. Each method will be briefly explained below.

[0029] [2.1.1.ATRP] Examples of initiators used in ATRP include organic halides and sulfonyl halide compounds. Among organic halides, organic halides having a highly reactive carbon-halogen bond are more preferred (carbonyl compounds having a halogen at the α-position, compounds having a halogen at the benzyl position, etc.). Specific examples of initiators are described in paragraphs

[0040] to

[0064] of JP 2005-232419 A.

[0030] The initiator is preferably a compound having two or more initiation points. The use of such an initiator makes it easy to control the molecular structure of the (meth)acrylic resin (A) to be produced to a preferred one. Specifically, it is easy to obtain a (meth)acrylic resin (A) having a (meth)acryloyl functional group at the molecular end and having 1.0 or more functional groups per molecule.

[0031] The (meth)acrylic monomer used in ATRP is not particularly limited, and any of the (meth)acrylic acid ester monomers exemplified in Section [1] can be suitably used.

[0032] The transition metal complex used as a polymerization catalyst in ATRP is not particularly limited. It is preferably a metal complex having an element of Group 7, 8, 9, 10, or 11 of the periodic table as the central metal. It is more preferably a transition metal complex having zero-valent copper, monovalent copper, divalent ruthenium, divalent iron, or divalent nickel as the central metal. It is even more preferably a complex having monovalent copper as the central metal. Examples of monovalent copper compounds used to form such complexes include cuprous chloride, cuprous bromide, cuprous iodide, cuprous cyanide, cuprous oxide, and cuprous perchlorate.

[0033] When a metal complex containing monovalent copper as the central metal is used as a polymerization catalyst, it is preferable to use a polydentate amine as a ligand, as this enhances catalytic activity. Examples of polydentate amines include 2,2'-bipyridine or its derivatives, 1,10-phenanthroline or its derivatives, tetramethylethylenediamine, pentamethyldiethylenetriamine, and hexamethyltris(2-aminoethyl)amine.

[0034] The ATRP polymerization reaction can be carried out in the absence of a solvent or in a solvent. Examples of solvents used in the polymerization are described in paragraph

[0067] of JP-A-2005-232419. A single solvent may be used, or two or more solvents may be used in combination. The polymerization reaction can also be carried out in an emulsion system or a system using supercritical fluid CO2 as a medium.

[0035] The polymerization temperature in ATRP is preferably 0 to 200°C, and more preferably room temperature (for example, 20°C) to 150°C.

[0036] [2.1.2.ARGET] ARGET is a form of ATRP. ARGET uses a reducing agent to regenerate the metal catalyst, significantly reducing the amount of metal catalyst used. This reduces the post-production purification burden and leads to cost savings.

[0037] In one embodiment, ARGET uses monovalent copper, a polydentate amine, a base other than the polydentate amine, and a reducing agent. In this polymerization system, the monovalent copper coordinated with the polydentate amine functions as a polymerization catalyst. The base other than the polydentate amine removes acid, a by-product of the catalytic cycle, and prevents the polydentate amine from being poisoned. The reducing agent reduces the divalent copper complex to an active monovalent copper complex. By controlling the addition rate of the reducing agent, the polymerization rate and heat of polymerization can be controlled.

[0038] In a preferred embodiment of ARGET, copper atoms are used in an amount of 5 to 30 ppm by weight relative to the total amount of (meth)acrylic monomers charged. In this embodiment, the amount of polydentate amine used is 7 mmol% or less of the entire polymerization system, and 150 mol% or less of the total amount of copper atoms. This polymerization system also contains a base and a reducing agent in addition to the polydentate amine.

[0039] (polydentate amines) Examples of polydentate amines include the following: One type of polydentate amine may be used alone, or two or more types may be used in combination. Bidentate and polydentate amines: 2,2-bipyridine, 4,4'-di-(5-nonyl)-2,2'-bipyridine, N-(n-propyl)pyridylmethanimine, N-(n-octyl)pyridylmethanimine Tridentate and multidentate amines: N,N,N',N'',N''-pentamethyldiethylenetriamine, N-propyl-N,N-di(2-pyridylmethyl)amine Tetradentate and polydentate amines: hexamethyltris(2-aminoethyl)amine, N,N-bis(2-dimethylaminoethyl)-N,N'-dimethylethylenediamine, 2,5,9,12-tetramethyl-2,5,9,12-tetraazatetradecane, 2,6,9,13-tetramethyl-2,6,9,13-tetraazatetradecane, 4,11-dimethyl-1,4,8,11-tetraazabicyclohexadecane, N',N''-dimethyl-N',N''-bis((pyridin-2-yl)methyl)ethane-1,2-diamine, tris[(2-pyridyl)methyl]amine, 2,5,8,12-tetramethyl-2,5,8,12-tetraazatetradecane Pentadentate polydentate amine: N,N,N',N'',N''',N'''',N''''-heptamethyltetraethylenetetramine Hexadentate polydentate amine: N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine Polyamine: Polyethyleneimine

[0040] Preferred polydentate amines are hexamethyltris(2-aminoethyl)amine and N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine. The use of these polydentate amines allows for a sufficient reaction rate while reducing the amount of transition metal atoms used (approximately 30 ppm or less relative to the (meth)acrylic monomer). Furthermore, the molecular weight distribution of the resulting (meth)acrylic resin is narrow.

[0041] (Bases other than polydentate amines) The base other than the polydentate amine may be a Bronsted base (a compound that accepts a proton) or a Lewis base (a compound that donates an unshared electron pair to form a coordinate bond). Examples of the base other than the polydentate amine include the following. Only one type of base other than the polydentate amine may be used, or two or more types may be used in combination. Monoamines: Monoamines are compounds that contain only one amine moiety that acts as a base. Examples of monoamines include primary amines (methylamine, aniline, lysine, etc.), secondary amines (dimethylamine, piperidine, etc.), tertiary amines (trimethylamine, triethylamine, etc.), aromatic amines (pyridine, pyrrole, etc.), and ammonia. Inorganic Base: An inorganic base is an element or compound from Group 1 or 2 of the periodic table. Examples of elements include lithium, sodium, and calcium. Examples of compounds include sodium methoxide, potassium ethoxide, methyllithium, sodium hydroxide, potassium hydroxide, potassium carbonate, sodium bicarbonate, ammonium bicarbonate, trisodium phosphate, disodium hydrogen phosphate, tripotassium phosphate, dipotassium hydrogen phosphate, sodium acetate, potassium acetate, sodium oxalate, potassium oxalate, sodium phenoxy, potassium phenoxy, sodium ascorbate, and potassium ascorbate. In addition, salts of weak acids (such as ammonium hydroxide) with strong bases are also inorganic bases.

[0042] The base other than the polydentate amine may be added directly to the reaction system or may be generated in the reaction system.

[0043] Bases other than polydentate amines are usually removed by purification after the production of the (meth)acrylic polymer (A). Therefore, amines with low boiling points or low costs are preferred. Examples of amines that satisfy these conditions include triethylamine and trimethylamine.

[0044] (reducing agent) Examples of reducing agents are described in paragraphs

[0083] to

[0095] of WO 2012 / 020545. Only one type of reducing agent may be used, or two or more types may be used in combination.

[0045] The reducing agent is usually removed by purification after the production of the (meth)acrylic polymer (A). Therefore, a reducing agent that can be easily purified or is low in cost is preferred. Examples of reducing agents that satisfy these conditions include ascorbic acid, ascorbic acid salts, and organotin compounds.

[0046] The lower limit of the amount of the reducing agent added is preferably 10 ppm or more relative to the total amount of (meth)acrylic acid monomer charged. The upper limit of the amount of the reducing agent added is preferably 100,000 ppm or less, more preferably 10,000 ppm or less, even more preferably 1,000 ppm or less, and particularly preferably 500 ppm or less relative to the total amount of (meth)acrylic acid monomer charged. If the amount of the reducing agent added is within the above range, sufficient polymerization activity can be expected, and removal by purification is also easy.

[0047] When the reducing agent is a solid substance at room temperature, it is preferable to add a solution of the reducing agent dissolved in a good solvent to the polymerization system, so that the reducing agent can more easily exert its effect.

[0048] As described above, the polymerization rate and heat of polymerization can be controlled by adjusting the rate of addition of the reducing agent. From the viewpoint of safety, it is preferable to add the reducing agent to the polymerization system in small amounts as the polymerization proceeds. The lower limit of the rate of addition of the reducing agent is preferably 10 mol% / Hr or more, more preferably 20 mol% / Hr or more, and even more preferably 30 mol% / Hr or more, relative to the copper complex. The upper limit of the rate of addition of the reducing agent is preferably 1000 mol% / Hr or less, more preferably 700 mol% / Hr or less, and even more preferably 500 mol% / Hr or less, relative to the copper complex.

[0049] [2.2. Method for introducing (meth)acryloyl-based functional groups] A known method can be used to introduce a (meth)acryloyl functional group represented by general formula (a) into the main chain of a (meth)acrylic polymer, as described, for example, in paragraphs

[0080] to

[0091] of JP-A No. 2004-203932.

[0050] In particular, a method in which the terminal halogen groups of a (meth)acrylic polymer represented by the following general formula (b) are substituted with a compound having a (meth)acryloyl functional group represented by the following general formula (c) is preferred, as this method makes it easy to control the reaction.

[0051] -CR 2 R 3 X...General formula (b) In the formula, R 2 and R 3 is a group bonded to the ethylenically unsaturated group of the (meth)acrylic monomer. X represents chlorine, bromine or iodine.

[0052] M +- OC(O)C(R 1 )=CH2...General formula (c) In the formula, R 1 is as explained for general formula (a). + represents an alkali metal ion or a quaternary ammonium ion. Examples of alkali metal ions include lithium ion, sodium ion, and potassium ion. Examples of quaternary ammonium ions include tetramethylammonium ion, tetraethylammonium ion, tetrabenzylammonium ion, trimethyldodecylammonium ion, tetrabutylammonium ion, and dimethylpiperidinium ion. Preferred M + is one or more ions selected from sodium ions and potassium ions.

[0053] A (meth)acrylic polymer having a terminal structure represented by general formula (b) can be produced by using an organic halide or sulfonyl halide compound described in Section [2.1.1.] as an initiator and a transition metal complex as a catalyst. Alternatively, a (meth)acrylic polymer having a terminal structure represented by general formula (b) can be produced by using a halide compound as a chain transfer agent. The former production method is preferred.

[0054] When reacting the polymer represented by general formula (b) with the compound represented by general formula (c), the ratio of the amount of the oxyanion in general formula (c) to the amount of the halogen group in general formula (b) is set to preferably 1.0 to 5.0 equivalents, more preferably 1.0 to 1.2 equivalents.

[0055] The solvent used in the introduction reaction is preferably a polar solvent, since the introduction reaction is a nucleophilic substitution reaction. Examples of polar solvents include tetrahydrofuran, dioxane, diethyl ether, acetone, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, hexamethylphosphoric triamide, and acetonitrile.

[0056] The reaction temperature for the introduction reaction is preferably 0 to 150° C. From the viewpoint of maintaining the polymerizability of the (meth)acryloyl-based functional group, the reaction temperature is more preferably room temperature (for example, 20° C.) to 100° C.

[0057] [3. Epoxy Compound and / or Oxetane Compound (B)] The curable composition according to one embodiment of the present invention contains an epoxy compound and / or an oxetane compound (B). The epoxy compound and the oxetane compound serve to improve the strength of the cured product. The oxetane compound also serves to reduce the viscosity of the curable composition, thereby improving workability. The epoxy compound and / or the oxetane compound (B) may be used alone or in combination of two or more types.

[0058] [3.1. Epoxy Compounds] The term "epoxy compound" generally refers to a compound having an epoxy group. Examples of the epoxy compound include aromatic epoxy compounds and alicyclic epoxy compounds. From the viewpoint of increasing the hardness of the cured product, aromatic epoxy compounds are preferred.

[0059] Furthermore, the epoxy compound preferably has a radical reactive group. Such an epoxy compound forms a crosslink with the (meth)acryloyl functional group of the (meth)acrylic polymer. Therefore, a tough cured product with low elution in solvents can be obtained. Examples of the radical reactive group include an acryloyl group, a methacryloyl group, and an allyl group. Epoxy compounds having a radical reactive group are available from Nippon Kayaku Co., Ltd., DIC Corporation, Showa Denko Materials Co., Ltd., etc.

[0060] Specific examples of aromatic epoxy compounds include bisphenol A epoxy compounds, bisphenol F epoxy compounds, bisphenol AD ​​epoxy compounds, hydrogenated bisphenol A epoxy compounds, and hydrogenated bisphenol F epoxy compounds. An example of an aromatic epoxy compound is 2,2-bis(4-glycidyloxyphenyl)propane.

[0061] Examples of alicyclic epoxy compounds include compounds having a cyclohexene oxide group, a tricyclodecene oxide group, a cyclopentene oxide group, etc. More specific examples of alicyclic epoxy compounds include vinylcyclohexene diepoxide, vinylcyclohexene monoepoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 2-(3,4-epoxycyclohexyl 5,5-spiro-3,4-epoxy)cyclohexane-m-dioxane, bis(3,4-epoxycyclohexyl)adipate, and bis(3,4-epoxycyclohexylmethylene)adipate.

[0062] 3.2. Oxetane Compounds Examples of the oxetane compound include 3-ethyl-3-hydroxymethyloxetane, 3-(meth)allyloxymethyl-3-ethyloxetane, (3-ethyl-3-oxetanylmethoxy)methylbenzene, 4-fluoro-[1-(3-ethyl-3-oxetanylmethoxy)methyl]benzene, 4-methoxy-[1-(3-ethyl-3-oxetanylmethoxy)methyl]benzene, [1-(3-ethyl-3-oxetanylmethoxy)ethyl]phenyl ether, isobutoxymethyl (3-ethyl-3-oxetanylmethyl) ether, isobutoxymethyl (3-ethyl-3-oxetanylmethyl) ether, isobutoxymethyl (3-ethyl-3-oxetanylmethyl) ether, isobutoxymethyl (3-ethyl-3-oxetanylmethoxy)methyl benzene, isobutoxymethyl (3-ethyl-3-oxetanylmethoxy)methyl benzene, isobutoxymethyl (3-ethyl-3-oxetanylmethoxy)ethyl phenyl ether, isobutoxymethyl (3-ethyl-3-oxetanylmethoxy)methyl ether, isobutoxymethyl (3-ethyl-3-oxetanylmethoxy)methyl benzene, isobutoxymethyl (3-ethyl-3-oxetanylmethoxy)methyl benzene, isobutoxymethyl (3-ethyl-3-oxetanylmethoxy)ethyl phenyl ether ... Isobornyloxyethyl (3-ethyl-3-oxetanylmethyl) ether, isobornyl (3-ethyl-3-oxetanylmethyl) ether, 2-ethylhexyl (3-ethyl-3-oxetanylmethyl) ether, ethyl diethylene glycol (3-ethyl-3-oxetanylmethyl) ether, dicyclopentadiene (3-ethyl-3-oxetanylmethyl) ether, dicyclopentenyloxyethyl (3-ethyl-3-oxetanylmethyl) ether, dicyclopentenylethyl (3-ethyl-3-oxetanylmethyl) ether ether, tetrahydrofurfuryl (3-ethyl-3-oxetanylmethyl) ether, tetrabromophenyl (3-ethyl-3-oxetanylmethyl) ether, 2-tetrabromophenoxyethyl (3-ethyl-3-oxetanylmethyl) ether, tribromophenyl (3-ethyl-3-oxetanylmethyl) ether, 2-tribromophenoxyethyl (3-ethyl-3-oxetanylmethyl) ether, 2-hydroxyethyl (3-ethyl-3-oxetanylmethyl) ether, 2-hydroxypropyl (3-ethyl-3-oxetanylmethyl) ether 3-ethyl-3-oxetanylmethyl) ether, butoxyethyl (3-ethyl-3-oxetanylmethyl) ether, pentachlorophenyl (3-ethyl-3-oxetanylmethyl) ether, pentabromophenyl (3-ethyl-3-oxetanylmethyl) ether, bornyl (3-ethyl-3-oxetanylmethyl) ether, 3,7-bis(3-oxetanyl)-5-oxa-nonane, 1,4-bis[(3-ethyl-3-oxetanylmethoxy)methyl]benzene, 1,2-bis[(3-ethyl-3-oxetanylmethoxy)methyl]ethane, 1,2-bis[(3-ethyl-3-oxetanylmethoxy)methyl]propane, ethylene glycol bis(3-ethyl-3-oxetanylmethyl) ether, dicyclopentenyl bis(3-ethyl-3-oxetanylmethyl) ether, triethylene glycol bis(3-ethyl-3-oxetanylmethyl) ether, tetraethylene glycol bis(3-ethyl-3-oxetanylmethyl) ether, tricyclodecanediyldimethylene bis(3-ethyl-3-oxetanylmethyl) ethyl) ether, 1,4-bis[(3-ethyl-3-oxetanylmethoxy)methyl]butane, 1,6-bis[(3-ethyl-3-oxetanylmethoxy)methyl]hexane, polyethylene glycol bis(3-ethyl-3-oxetanylmethyl) ether, EO-modified bisphenol A bis(3-ethyl-3-oxetanylmethyl) ether, PO-modified bisphenol A bis(3-ethyl-3-oxetanylmethyl) ether, EO-modified hydrogenated bisphenol A bis(3-ethyl bisphenol A bis(3-ethyl-3-oxetanylmethyl) ether, PO-modified hydrogenated bisphenol A bis(3-ethyl-3-oxetanylmethyl) ether, EO-modified bisphenol F bis(3-ethyl-3-oxetanylmethyl) ether, trimethylolpropane tris(3-ethyl-3-oxetanylmethyl) ether, pentaerythritol tris(3-ethyl-3-oxetanylmethyl) ether, pentaerythritol tetrakis(3-ethyl-3-oxetanylmethyl) ether, diphenyl ether Examples of such ethers include dipentaerythritol hexakis(3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol pentakis(3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol tetrakis(3-ethyl-3-oxetanylmethyl) ether, caprolactone-modified dipentaerythritol hexakis(3-ethyl-3-oxetanylmethyl) ether, and ditrimethylolpropane tetrakis(3-ethyl-3-oxetanylmethyl) ether.

[0063] The weight ratio of the (meth)acrylic polymer (A) to the epoxy compound and / or oxetane compound (B) in the curable composition is preferably 1:99 to 50:50, more preferably 2:98 to 40:60, and even more preferably 3:97 to 30:70. When the blending ratio of the two is within the above range, sufficient strength and elongation can be imparted to the cured product.

[0064] [4. Photoradical polymerization initiator (C)] The curable composition according to one embodiment of the present invention contains a photoradical polymerization initiator (C). The photoradical polymerization initiator (C) serves to cure the curable composition when triggered by light irradiation (such as UV irradiation). The photoradical polymerization initiator (C) may be used alone or in combination of two or more types.

[0065] Examples of the photoradical polymerization initiator (C) include acetophenone, propiophenone, benzophenone, xanthol, fluorene, benzaldehyde, anthraquinone, triphenylamine, carbazole, 3-methylacetophenone, 4-methylacetophenone, 3-pentylacetophenone, 2,2-diethoxyacetophenone, 4-methoxyacetophenone, 3-bromoacetophenone, 4-allylacetophenone, p-diacetylbenzene, 3-methoxybenzophenone, 4-methylbenzophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, 4-chloro-4'-benzylbenzophenone, 3-chloroxanthone, 3,9-dichloroxanthone, and 3-chloro- 8-nonylxanthone, benzoyl, benzoin methyl ether, benzoin butyl ether, bis(4-dimethylaminophenyl) ketone, benzyl methoxy ketal, 2-chlorothioxanthone, 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, 2-(dimethylamino)-2-(4-methylbenzyl)-1-(4-morpholinophenyl)butan-1-one).

[0066] Further examples of the photoradical polymerization initiator (C) include acylphosphine oxide-based photopolymerization initiators. Acylphosphine oxide-based photopolymerization initiators are preferred because they have excellent deep curing properties when irradiated with UV light. Examples of acylphosphine oxide-based photopolymerization initiators include 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, bis(2,6-dimethylbenzoyl)-phenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-isobutylphosphine oxide, bis(2,6-dimethoxybenzoyl)-isobutylphosphine oxide, and bis(2,6-dimethoxybenzoyl)-phenylphosphine oxide. Among these, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide are preferred.

[0067] Among the above-mentioned photoradical polymerization initiators (C), 1-hydroxycyclohexylphenylketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2,2-dimethoxy-1,2-diphenylethan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide are preferred because of their high reactivity.

[0068] The amount of the photoradical polymerization initiator (C) is preferably 0.01 to 5 parts by weight, relative to 100 parts by weight of the total weight of the (meth)acrylic polymer (A) and the epoxy compound and / or oxetane compound (B), and more preferably 0.05 to 1 part by weight from the viewpoint of achieving both deep curability and light transmittance of the cured product.

[0069] [5. Epoxy Hardener (D)] The curable composition contains an epoxy curing agent (D). A wide variety of conventionally known epoxy curing agents can be used as the epoxy curing agent (D). Examples of the epoxy curing agent (D) include amine-based curing agents, imidazole-based curing agents, and acid anhydride-based curing agents. The epoxy curing agent (D) may be used alone or in combination of two or more types.

[0070] Examples of amine-based curing agents include aliphatic amines (diethylenetriamine, triethylenetetraamine, tetraethylenepentamine, diethylaminopropylamine, hexamethylenediamine, methylpentamethylenediamine, trimethylhexamethylenediamine, guanidine, oleylamine, etc.); alicyclic amines (menthenediamine, isophoronediamine, norbornanediamine, piperidine, N,N'-dimethylpiperazine, N-aminoethylpiperazine, 1,2-diaminocyclohexane, bis(4-amino-3-methylcyclohexyl)methane, bis(4-aminocyclohexane), (cyclohexyl)methane, polycyclohexylpolyamine, 1,8-diazabicyclo[5,4,0]undecene-7 (DBU), etc.; amines with ether bonds (3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiro[5,5]undecane (ATU), morpholine, N-methylmorpholine, polyoxypropylenediamine, polyoxypropylenetriamine, polyoxyethylenediamine, etc.); hydroxyl group-containing amines (diethanolamine, triethanolamine, etc.); aromatic amines (tris-2,4,6-dimethylaminomethylphenol, etc.);Aminosilanes (γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltriisopropoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-(2-aminoethyl)aminopropyltrimethoxysilane, γ-(2-aminoethyl)aminopropylmethyldimethoxysilane, γ-(2-aminoethyl)aminopropyltriethoxysilane, γ-(2-aminoethyl)aminopropylmethyldiethoxysilane, γ-(2-aminoethyl)aminopropyltriisopropoxysilane, γ-(2-(2-aminoethyl)aminoethyl)aminopropyltrimethoxysilane, γ-(6-aminohexyl)aminopropyltrimethoxysilane, 3-(N-ethylamino)-2-methylpropyltrimethoxysilane, 2-aminoethylaminomethyltrimethoxysilane, N-cyclohexylaminomethyltriethoxy Silanes, N-cyclohexylaminomethyldiethoxymethylsilane, γ-ureidopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-phenylaminomethyltrimethoxysilane, N-benzyl-γ-aminopropyltrimethoxysilane, N-vinylbenzyl-γ-aminopropyltriethoxysilane, N-(3-triethoxysilylpropyl)-4,5-dihydroimidazole, N-cyclohexylaminomethyltriethoxysilane, N-cyclohexylaminomethyldiethoxymethylsilane, N-phenylaminomethyltrimethoxysilane, (2-aminoethyl)aminomethyltrimethoxysilane, N,N'-bis[3-(trimethoxysilyl)propyl]ethylenediamine, etc.; ketimine-type silanes (N-(1,3-dimethylbutylidene)-3-(triethoxysilyl)-1-propanamine, etc.);

[0071] Examples of imidazole curing agents include 2-phenylimidazole, 2-ethyl-4(5)-methylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyano-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-phenylimidazole trimellitate ... Examples of imidazole-based curing agents include -[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole. Adducts of epoxy compounds with the above-mentioned imidazole compounds are also examples of imidazole-based curing agents.

[0072] Examples of acid anhydride curing agents include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride, and dodecylsuccinic anhydride.

[0073] Further examples of the epoxy curing agent (D) include polyamidoamines (such as polyamides obtained by reacting a dimer acid with a polyamine (diethylenetriamine, triethylenetetramine, etc.), and polyamides obtained by reacting a polycarboxylic acid other than a dimer acid with a polyamine); dicyandiamide; and modified amines (such as epoxy-modified amines obtained by reacting an amine with an epoxy compound, Mannich-modified amines obtained by reacting an amine with formalin or a phenol compound, Michael addition-modified amines, and ketimines).

[0074] From the viewpoint of the curability of the epoxy compound and / or oxetane compound (B), the epoxy curing agent (D) is preferably an amine-based curing agent. Furthermore, from the viewpoint of the storage stability of the curable composition, the epoxy curing agent (D) is preferably a tertiary amine compound.

[0075] The amount of the epoxy curing agent (D) is preferably 1 to 200 parts by weight, more preferably 5 to 100 parts by weight, based on 100 parts by weight of the epoxy compound and / or oxetane compound (B). When the amount of the epoxy curing agent (D) is within the above range, the curability of the curable composition can be improved and the elution of components from the cured product can be reduced.

[0076] [6. Other Ingredients] In addition to the above-described (A) to (D), the curable composition according to one embodiment of the present invention may contain various additives depending on the purpose. Examples of the additives include polymerizable monomers and / or oligomers, fillers, plasticizers, solvents, thixotropic agents, antioxidants, and other additives. Each of these additives may be used alone or in combination of two or more.

[0077] 6.1. Polymerizable Monomers and / or Oligomers Addition of polymerizable monomers and / or oligomers can, for example, reduce the viscosity of the curable composition, improve the curability, and improve the mechanical properties of the cured product. Examples of polymerizable monomers and / or oligomers include the substances described in

[0110] to

[0124] of JP 2006-274085 A.

[0078] The blending amount of the polymerizable monomer and / or oligomer is preferably 10 to 200 parts by weight, more preferably 20 to 150 parts by weight, and even more preferably 30 to 100 parts by weight, relative to 100 parts by weight of the (meth)acrylic polymer (A). When the blending amount is within the above range, there is an advantage that the viscosity is reduced and workability is improved. Only one type of polymerizable monomer and / or oligomer may be used, or two or more types may be used in combination.

[0079] 6.2 Fillers Addition of a filler can adjust the thixotropy of the curable composition and impart mechanical strength and abrasion resistance to the cured product. Examples of fillers include the fillers and hollow microparticles described in

[0134] to

[0151] of JP-A-2006-291073.

[0080] Specific examples of fillers include reinforcing silica such as finely powdered silica (fumed silica, wet-process silica, etc.), carbon black, wood flour, pulp, cotton chips, mica, walnut shell powder, rice husk powder, graphite, white clay, silica (crystalline silica, fused silica, dolomite, silicic anhydride, hydrous silicic acid, etc.), heavy calcium carbonate, colloidal calcium carbonate, magnesium carbonate, diatomaceous earth, calcined clay, clay, talc, titanium oxide, bentonite, organic bentonite, ferric oxide, red iron oxide, fine aluminum powder, flint powder, zinc oxide, activated zinc white, zinc powder, zinc carbonate, shirasu balloons, beads (made of polyacrylic resin, polyacrylonitrile-vinylidene chloride resin, phenolic resin, polystyrene resin, etc.), hollow particles thereof, inorganic hollow particles (glass balloons, shirasu balloons, fly ash balloons, etc.), and fibrous fillers (glass fiber, glass filament, carbon fiber, Kevlar fiber, polyethylene fiber, etc.). Among these, from the viewpoint of excellent reinforcing properties, one or more selected from the group consisting of fumed silica, wet process silica, carbon black, heavy calcium carbonate and hard calcium carbonate are preferred.

[0081] The particle size of fumed silica and wet-process silica is preferably 50 μm or less. The specific surface area of ​​fumed silica and wet-process silica is preferably 80 m 2 / g or more is preferred. Such fumed silica and wet-process silica can sufficiently enhance reinforcing properties. In this specification, the specific surface area value refers to a value measured by the BET method. As the silica used as a filler, surface-untreated silica is preferred to surface-treated silica (for example, silica surface-treated with organosilane, organosilazane, diorganocyclopolysiloxane, etc.). Surface-untreated silica has the advantages of being easy to knead, improving the fluidity of the curable composition, and being economical.

[0082] An example of commercially available fumed silica is AEROSIL (manufactured by Nippon Aerosil Co., Ltd.). An example of commercially available wet-process silica is Nipsil (manufactured by Tosoh Silica Corporation).

[0083] Examples of carbon black include channel black, furnace black, acetylene black, and thermal black. From the viewpoints of reinforcing properties and economy, furnace black is preferred.

[0084] The amount of filler to be added is preferably 0.1 to 500 parts by weight, more preferably 0.5 to 200 parts by weight, and even more preferably 1 to 50 parts by weight, relative to 100 parts by weight of the (meth)acrylic polymer (A). When the amount is within the above range, both the reinforcement property of the cured product and the workability of the curable composition can be achieved. Only one type of filler may be used, or two or more types may be used in combination.

[0085] 6.3 Plasticizers The addition of a plasticizer can adjust the viscosity of the curable composition and the mechanical properties (tensile strength, elongation, etc.) of the cured product, and can also improve the transparency of the cured product.

[0086] Examples of plasticizers include phthalate esters (dibutyl phthalate, diheptyl phthalate, di(2-ethylhexyl) phthalate, butyl benzyl phthalate, etc.); aromatic esters of polyalkylene glycols (diethylene glycol dibenzoate, triethylene glycol dibenzoate, etc.); phosphate esters (tricresyl phosphate, tributyl phosphate, etc.); trimellitic esters; pyromellitic esters; polystyrene-based resins (polystyrene, poly-α-methylstyrene, etc.); ester-based plasticizers obtained by reacting saturated aliphatic alcohols and saturated fatty acids; polybutadiene; polybutene; polyisobutylene; butadiene. Examples of suitable polymers include acrylonitrile, polychloroprene, chlorinated paraffin, hydrocarbon oils (such as alkyldiphenyls and partially hydrogenated terphenyls), process oils, polyethers (such as polyether polyols (such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol), and derivatives of polyether polyols in which the hydroxyl groups have been converted to ester groups or ether groups), epoxy plasticizers (such as epoxidized soybean oil and benzyl epoxy stearate), and (meth)acrylic polymers obtained by polymerizing vinyl monomers using various methods (such as acrylic plasticizers; commercially available products include the ARUFON series (manufactured by Toagosei Co., Ltd.)).

[0087] The amount of the plasticizer is preferably 1 to 100 parts by weight, more preferably 1 to 50 parts by weight, per 100 parts by weight of the (meth)acrylic polymer (A). When the amount is within the above range, the workability of the curable composition is good and the effect on the mechanical properties of the obtained cured product is small. Only one type of plasticizer may be used, or two or more types may be used in combination.

[0088] 6.4 Solvents Examples of solvents include aromatic hydrocarbon solvents (toluene, xylene, etc.); ester solvents (ethyl acetate, butyl acetate, amyl acetate, cellosolve acetate, etc.); ketone solvents (acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, etc.); alcohol solvents (methanol, ethanol, isopropanol, etc.); and hydrocarbon solvents (hexane, cyclohexane, methylcyclohexane, heptane, octane, etc.).

[0089] The amount of the solvent is preferably 50 parts by weight or less, more preferably 30 parts by weight or less, based on 100 parts by weight of the (meth)acrylic polymer (A). When the amount is within the above range, the workability of the curable composition is improved and the effect of cure shrinkage is small. Furthermore, from the viewpoint of minimizing the effect on the working environment, the amount is more preferably 10 parts by weight or less based on 100 parts by weight of the (meth)acrylic polymer (A). Only one type of solvent may be used, or two or more types may be used in combination.

[0090] [6.5. Thixotropic Agents] Addition of a thixotropic agent (anti-sagging agent) can prevent sagging and improve workability.

[0091] Examples of the thixotropy inhibitor include hydrogenated castor oil derivatives, metal soaps having a long-chain alkyl group, ester compounds having a long-chain alkyl group, inorganic fillers (such as silica), and amide waxes.

[0092] The amount of the thixotropy-imparting agent is preferably 0.1 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the (meth)acrylic polymer (A). When the amount is within the above range, the workability of the curable composition is improved. The thixotropy-imparting agent may be used alone or in combination of two or more types.

[0093] 6.6. Antioxidants Addition of an antioxidant (anti-aging agent) can improve the heat resistance of the cured product.

[0094] Examples of antioxidants include primary antioxidants (hindered phenol antioxidants, amine antioxidants, lactone antioxidants, ethanolamine antioxidants, etc.) and secondary antioxidants (sulfur-based oxidants, phosphorus-based oxidants, etc.). Further examples of antioxidants include the substances described in

[0232] to

[0235] of JP 2007-308692 A and the substances described in

[0089] to

[0093] of WO 2005 / 116134 A.

[0095] The amount of the antioxidant to be added is preferably 0.1 to 5 parts by weight, more preferably 0.1 to 3 parts by weight, based on 100 parts by weight of the (meth)acrylic polymer (A). When the amount is within the above range, the heat resistance effect is sufficiently exhibited and there is no economic disadvantage.

[0096] 6.7. Other additives Examples of other additives include compatibilizers, curing regulators, radical inhibitors, metal deactivators, antiozonants, phosphorus-based peroxide decomposers, lubricants, pigments, antifoaming agents, foaming agents, anti-termite agents, anti-fungal agents, ultraviolet absorbers, and light stabilizers. Further examples of other additives include those described in JP-A-63-006041, JP-A-63-006003, JP-A-63-254149, JP-A-64-022904, and JP-A-2001-072854.

[0097] [7. Curing method] The curable composition according to one embodiment of the present invention is cured by both photoradical curing and thermal curing.

[0098] Photoradical curing is initiated by irradiation with active energy rays (such as UV or electron beams). The active energy ray source can be appropriately selected depending on the properties of the photoradical polymerization initiator (C). Examples of active energy ray sources include high-pressure mercury lamps, low-pressure mercury lamps, LEDs, electron beam irradiation devices, halogen lamps, light-emitting diodes, and semiconductor lasers.

[0099] Thermosetting is an effect initiated by heating. The thermosetting temperature is set appropriately depending on the type of epoxy compound and / or oxetane compound (B), epoxy curing agent (D), and other additives. The thermosetting temperature is preferably 15 to 300°C, more preferably 15 to 250°C. Within the above temperature range, deterioration of the cured product due to heat can be prevented. A heating furnace, oven, heating conveyor, etc. can be used for thermosetting.

[0100] [8.Applications] The curable composition according to one embodiment of the present invention has good electrical insulation properties and is therefore suitable for use in electrical and electronic components, resist materials, etc. However, the use is not limited to these applications and can be used in a variety of applications.

[0101] Examples of electrical and electronic components include electrical insulating materials (such as insulating coatings for electric wires and cables), sealing materials, adhesives, pressure-sensitive adhesives, conformal coatings, potting agents for electrical and electronic applications, packing, O-rings, and belts. More specific examples include high-voltage thick-film resistors, circuit elements for hybrid ICs, HICs, electrical insulating components, semiconducting components, conductive components, modules, printed circuits, ceramic substrates, diodes, buffer materials for transistors or bonding wires, coating materials for optical fibers for optical communications, high-voltage transformer circuits, printed circuit boards, high-voltage transformers with variable resistors, electrical insulating components, solar cells (such as crystalline silicon solar cells, amorphous silicon solar cells, CI(G)S solar cells, perovskite solar cells, organic thin-film solar cells, dye-sensitized solar cells, and GaAs solar cells), potting materials for TV flyback transformers, heavy electrical components, low-voltage electrical components, backside sealing materials for solar cells, and sealing materials for circuits and substrates of electrical and electronic devices.

[0102] Examples of resist materials include peripheral components for semiconductors and conductors. More specific examples include photomasks, photoresists, semiconductor surface protection tapes, dicing tapes, die bonding tapes, die bonding materials, interlayer insulating materials (build-up materials), photosensitive dry film resists, liquid photosensitive resin materials, interposer materials, package substrate materials, solder resists, semiconductor encapsulation resins, underfill materials, sidefill materials, printed circuit board materials, and modifiers for these materials.

[0103] Further suitable applications include components that transmit light (ultraviolet rays, visible light, infrared rays, X-rays, lasers, etc.). Examples include display peripheral components and UV inks for 3D printing. More specific examples include flat panel displays and their encapsulants; peripheral materials for liquid crystal display devices (such as light guide plates, prism sheets, polarizing plates, retardation plates, viewing angle correction films, front glass protective films, polarizer protective films or adhesives, adhesives or fillers between panels or films, and liquid crystal films in the field of liquid crystal displays); encapsulants, anti-reflection films, optical correction films, front glass protective films or adhesives, adhesives or fillers between panels or films for color PDPs (plasma displays); molding materials for light-emitting elements used in light-emitting diode display devices, encapsulants for light-emitting diodes (LEDs), front glass protective films or adhesives, adhesives or fillers between panels or films; and light guide plates, prism sheets, polarizing plates, retardation plates, and viewing angle correction films for plasma-addressed liquid crystal (PALC) displays. , polarizer protective films or adhesives, adhesives or fillers between panels or films; protective films or adhesives for the front glass in organic EL (electroluminescence) displays, adhesives or fillers between panels or films; protective films or adhesives, adhesives or fillers between panels or films in organic TFT (organic thin film transistor) displays; various film substrates, protective films or adhesives for the front glass, adhesives or fillers between panels or films in field emission displays (FEDs); protective films or adhesives, adhesives or fillers between panels or films in electronic paper; protective films or adhesives, adhesives or fillers between panels or films for touch panels, mobile phone displays, and car navigation displays; and peripheral materials for the above display devices.

[0104] [9. Summary] The present invention includes the following aspects. <1> a (meth)acrylic polymer (A); an epoxy compound and / or an oxetane compound (B); a photoradical polymerization initiator (C); an epoxy curing agent (D); Contains the weight ratio of the (meth)acrylic polymer (A) to the epoxy compound and / or oxetane compound (B) is (1:99) to (50:50); The (meth)acrylic polymer (A) is The molecular weight distribution (Mw / Mn) is 1.8 or less, The total amount of bromine and potassium contained in the polymer is 0 ppm or more and 25 ppm or less, and The (meth)acryloyl functional group represented by the following general formula (a) has 1.0 or more per molecule: -OC(O)C(R 1 )=CH2...General formula (a) (In the formula, R 1 represents a hydrogen atom or an organic group having 1 to 20 carbon atoms. Curable composition. <2> The (meth)acrylic polymer (A) has the (meth)acryloyl functional group at the molecular terminal. <1> The curable composition according to claim 1. <3> the (meth)acrylic polymer (A) contains 0 ppm or more and 15 ppm or less of bromine element; <1> or <2> The curable composition according to claim 1. <4> The epoxy compound and / or oxetane compound (B) is an aromatic epoxy compound. <1> ~ <3> The curable composition according to any one of the preceding claims. <5> The epoxy compound and / or oxetane compound (B) is an epoxy compound having a radical reactive group. <1> ~ <4> The curable composition according to any one of claims 1 to 10. <6> The epoxy curing agent (D) is an amine compound. <1> ~ <5> The curable composition according to any one of claims 1 to 10. <7> a step of producing the (meth)acrylic polymer (A) using a copper complex, a polydentate amine, a base other than a polydentate amine, and a reducing agent; a step of mixing the obtained (meth)acrylic polymer (A), the epoxy compound and / or oxetane compound (B), the photoradical polymerization initiator (C), and the epoxy curing agent (D); Including, <1> ~ <6> 10. A method for producing the curable composition according to claim 9.

[0105] In addition to the above aspects, the present invention also includes the following aspects. <a1> The (meth)acrylic polymer (A) may be produced by a living polymerization method. <a2> The living polymerization method may be a living radical polymerization method. [Example]

[0106] Specific examples of the present invention are shown below, but the present invention is not limited to the following examples.

[0107] [Method for measuring physical properties of (meth)acrylic resin] [1. Number average molecular weight and molecular weight distribution] The number average molecular weight and molecular weight distribution (ratio of weight average molecular weight to number average molecular weight) were calculated by a standard polystyrene conversion method using gel permeation chromatography (GPC).

[0108] The GPC column used was a column packed with cross-linked polystyrene gel (Shodex GPC K-804 and K-802.5, manufactured by Showa Denko KK) and chloroform was used as the GPC solvent.

[0109] [2. Content of ionic elements] The contents of ionic elements (bromine and potassium) were analyzed using ICP-MS (HP-4500, manufactured by Yokogawa Analytical Systems, Inc.).

[0110] [3. Number of functional groups introduced in the functionalization process] The number of functional groups introduced per polymer molecule is 1 The concentration was calculated based on the concentration analysis by H-NMR and the number average molecular weight. The NMR apparatus used was an ASX-400 (manufactured by Bruker). Deuterated chloroform was used as the solvent for NMR.

[0111] [Production Example of (Meth)acrylic Resin] The reagents used in the production examples were mass-produced products with industrialization in mind, and were used without any treatment such as purification after being procured.

[0112] [Manufacturing Example 1] <1. Polymerization process> 1. 100 parts by weight of n-butyl acrylate, 20 parts by weight of methanol, 1.76 parts by weight of diethyl 2,5-dibromoadipate, and 955 ppm of triethylamine (EtN) were charged and stirred under a nitrogen stream at 45°C. Triethylamine is an amine other than a polydentate amine. 2. A copper bromide solution was prepared by mixing 107 ppm of copper(II) bromide, 109 ppm of hexamethyltris(2-aminoethyl)amine (purity: 96%), and 0.43 parts by weight (0.54 parts by volume) of methanol. The copper content in the copper bromide solution was 30 ppm, and the amount of hexamethyltris(2-aminoethyl)amine was equivalent to that of copper. Hexamethyltris(2-aminoethyl)amine is a polydentate amine. 3. An ascorbic acid solution was prepared by mixing 17 ppm ascorbic acid with 0.10 parts by weight (0.13 parts by volume) of methanol. Ascorbic acid corresponds to a reducing agent. 4. The copper bromide solution and ascorbic acid solution were added to the reaction system to initiate the reaction. During the reaction, the ascorbic acid solution was added appropriately, and the reaction solution was heated and stirred continuously so that the temperature was kept between 45°C and 70°C. 5. 153 minutes after the start of polymerization, the conversion of n-butyl acrylate reached 94 mol%. At this point, the volatile matter was removed by devolatilization under reduced pressure to obtain (meth)acrylic polymer X. The amount of ascorbic acid and the amount of methanol added to the reaction system up to this point were 432 ppm and 65.4 parts by weight (81.8 parts by volume), respectively.

[0113] The number average molecular weight of the (meth)acrylic polymer X was 21,200, and the molecular weight distribution was 1.10.

[0114] <2. Adsorption filtration purification process (1)> 6. The (meth)acrylic polymer X obtained in the polymerization step was diluted with 100 parts by weight of butyl acetate to prepare a polymer solution. 7. An adsorbent was added to the polymer solution, and the mixture was heated and stirred for 1 hour at approximately 100° C. The adsorbents used were Kyoward 700SEN (adsorbent / manufactured by Kyowa Chemical Industry Co., Ltd.) and Kyoward 500SH (adsorbent / manufactured by Kyowa Chemical Industry Co., Ltd.), each in an amount of 1 part by weight. 8. The polymer slurry solution containing insoluble components (such as adsorbent) was filtered to separate the solid and liquid, thereby obtaining a clear polymer solution.

[0115] <3.Functionalization process> 9. To the polymer solution obtained in the adsorption filtration purification step (1), 2.0 parts by weight of potassium acrylate, 0.3 parts by weight of tetrabutylammonium bromide, and 0.01 parts by weight of H-TEMPO were added. 10. Using an autoclave, the mixture was heated and stirred for 2 hours at an internal temperature of 120° C. This yielded a (meth)acrylic polymer Y having a terminal functional group represented by “—OC(O)CH═CH2.”

[0116] In the (meth)acrylic polymer Y, the number of terminal functional groups introduced was two per molecule.

[0117] <4a. Water purification process> 11a. 400 parts by weight of water was added to the polymer solution of (meth)acrylic polymer Y obtained in the functionalization step. After stirring for 5 minutes at an internal temperature of 80°C, the mixture was allowed to stand for 10 minutes. This step caused the solution to separate into two phases, with an organic phase (polymer solution) formed on top and an aqueous phase formed on the bottom. 12a. The aqueous phase was removed from the bottom of the autoclave, and then the organic phase was subjected to devolatilization under reduced pressure at 130°C to obtain a clear (meth)acrylic polymer (1).

[0118] The (meth)acrylic polymer (1) had a number average molecular weight of 21,800 and a molecular weight distribution of 1.11. The (meth)acrylic polymer (1) contained 5 ppm of bromine and 2 ppm of potassium.

[0119] [Manufacturing Example 2] The polymerization step, adsorption / filtration / purification step (1), and functionalization step were the same as those in Production Example 1. After the functionalization step, the following adsorption / filtration / purification step (2) was carried out instead of the above-mentioned water purification step.

[0120] <4b. Adsorption filtration purification process (2)> 11b. An adsorbent was added to the polymer solution of (meth)acrylic polymer Y obtained in the functionalization step, and the mixture was heated and stirred at 100°C for 1 hour. Kyoward 700SEN (manufactured by Kyowa Chemical Industry Co., Ltd.) and Kyoward 500SH (manufactured by Kyowa Chemical Industry Co., Ltd.) were used as the adsorbent, in an amount of 1 part by weight each. 12b: The polymer slurry solution containing insoluble components (such as adsorbents) was filtered, and then devolatilized under reduced pressure at 130°C to obtain a clear (meth)acrylic polymer (2).

[0121] The (meth)acrylic polymer (2) had a number average molecular weight of 21,900 and a molecular weight distribution of 1.12. The (meth)acrylic polymer (2) contained 20 ppm of bromine and 11 ppm of potassium. Therefore, the (meth)acrylic polymer (2) does not fall under the category of the (meth)acrylic polymer (A) referred to in this specification.

[0122] [Preparation of evaluation samples] Samples for evaluating physical properties were prepared by the following method.

[0123] [1. Preparation of curable composition] The components according to the composition shown in Table 1 below were added to a disposable cup and stirred with a spatula. The mixture was then stirred at 1600 rpm for 1.5 minutes and degassed at 2200 rpm for 3 minutes using a planetary centrifugal mixer (Thinky Mixer). A curable composition was thus obtained.

[0124] The components contained in the curable composition are as follows: (Meth)acrylic polymer (A) (Meth)acrylic polymer (1): obtained in Production Example 1 (Meth)acrylic polymer (2): obtained in Production Example 2 Epoxy compounds and / or oxetane compounds (B) Epoxy compound (B1): An epoxy compound having a glycidyl group and an acryloyl group. Epoxy compound (B2): 2,2-bis(4-glycidyloxyphenyl)propane (jER828, manufactured by Mitsubishi Chemical Corporation) Photoradical polymerization initiator (C) Photoradical polymerization initiator (C1): 2-hydroxy-2-methyl-1-phenyl-propan-1-one (Omnirad 1173, manufactured by IGM Resins BV) Photoradical polymerization initiator (C2): Bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (Ominirad819, manufactured by IGM Resins BV) ●Epoxy hardener (D) Epoxy hardener (D1): Tris-2,4,6-dimethylaminomethylphenol (Ankamine K54, manufactured by EVONIK)

[0125] [2a. Preparation of sample for three-point bending test] 1. The curable composition was poured into a Teflon (registered trademark) mold (width 10 mm, length 100 mm, thickness 2 mm). 2. Preheating was carried out at 80°C for 20 minutes. Thereafter, the curable composition was irradiated with UV light using a UV irradiation device (LIGHT HAMMER 6, manufactured by Fusion UV Systems). The irradiated light was a mercury lamp with a peak irradiance of 250 mW / cm. 2 , Accumulated light intensity: 2,000mJ / cm 2 It was. 3. The composition was heated at 150°C for 60 minutes to obtain a cured product.

[0126] [2b. Preparation of sample for volume resistivity measurement] A cured product was prepared using the same procedure as for preparing the sample for the three-point bending test, except that the size of the Teflon (registered trademark) mold was changed to 100 mm wide, 100 mm long, and 2 mm thick.

[0127] [Method for evaluating physical properties of cured product] [Three-point bending test] A jig with an indenter radius of 5 mm and a fulcrum radius of 2 mm was used. The distance between the fulcrums was 32 mm. An autograph (AG-2000A, manufactured by Shimadzu Corporation) was used for the measurements. The measurement temperature was 23°C and the strain rate was 2 mm / min.

[0128] [Volume resistivity] The specific volume resistivity was measured using an R8340 Ultra High Resistance Meter (manufactured by Advantest) according to a method in accordance with JIS K 6911. It can be said that the higher the specific volume resistivity, the better the electrical insulation.

[0129] [Table 1]

[0130] As can be seen from Table 1, the cured product containing (meth)acrylic polymer (1) had a higher volume resistivity and better electrical insulation than the cured product containing (meth)acrylic polymer (2). The difference between (meth)acrylic polymer (1) and (meth)acrylic polymer (2) is the total content of ionic elements (bromine and potassium).

[0131] Comparison of Examples and Comparative Examples confirmed that the mechanical properties of the cured product were not affected even when the total content of bromine and potassium elements was reduced. Furthermore, comparison of Examples and Comparative Examples with Reference Examples confirmed that the mechanical properties of the cured product were improved even when a (meth)acrylic polymer with a reduced total content of bromine and potassium elements was blended. [Industrial Applicability]

[0132] One aspect of the present invention can be utilized in the field of curable compositions.

Claims

1. a (meth)acrylic polymer (A); an epoxy compound and / or an oxetane compound (B); a photoradical polymerization initiator (C); an epoxy curing agent (D); Contains the weight ratio of the (meth)acrylic polymer (A) to the epoxy compound and / or oxetane compound (B) is (1:99) to (50:50); The (meth)acrylic polymer (A) is The molecular weight distribution (Mw / Mn) is 1.8 or less, The total amount of bromine and potassium contained in the polymer is 7 ppm or more and 15 ppm or less, and The (meth)acryloyl functional group represented by the following general formula (a) has 1.0 or more per molecule: -OC(O)C(R) １ ) = CH ２ ...General form (a) (In the formula, R １ represents a hydrogen atom or an organic group having 1 to 20 carbon atoms) Curable composition.

2. The curable composition according to claim 1, wherein the (meth)acrylic polymer (A) has the (meth)acryloyl functional group at a molecular terminal.

3. The curable composition according to claim 1 or 2, wherein the (meth)acrylic polymer (A) contains 5 ppm or more and 15 ppm or less of elemental bromine.

4. The curable composition according to any one of claims 1 to 3, wherein the epoxy compound and / or oxetane compound (B) is an aromatic epoxy compound.

5. The curable composition according to any one of claims 1 to 4, wherein the epoxy compound and / or oxetane compound (B) is an epoxy compound having a radical reactive group.

6. The curable composition according to any one of claims 1 to 5, wherein the epoxy curing agent (D) is an amine compound.

7. The curable composition according to any one of claims 1 to 6, wherein the (meth)acrylic polymer (A) contains 10 ppm or less of elemental bromine.

8. The curable composition according to any one of claims 1 to 7, wherein the (meth)acrylic polymer (A) contains 10 ppm or less of elemental bromine and elemental potassium in total.

9. A method for producing the curable composition according to any one of claims 1 to 8, comprising: a step of producing the (meth)acrylic polymer (A) using a copper complex, a polydentate amine, a base other than the polydentate amine, and a reducing agent; a step of mixing the obtained (meth)acrylic polymer (A), the epoxy compound and / or oxetane compound (B), the photoradical polymerization initiator (C), and the epoxy curing agent (D); A method for producing a curable composition, comprising:

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