Curable composition and cured product thereof

Abstract

A curable composition contains the following (A) component and (B) component. (A) component: a monofunctional radical polymerizable compound containing a compound represented by the following formula [1], (B) component: a radical initiator. X 1 -X 2 -X 3 -X 4 [1] (In formula [1], X 1 represents a structure selected from the following formulae [1-a] to [1-g]. X 2 represents a linear alkylene group having 2 to 14 carbon atoms. The alkylene group is optionally substituted in a specific manner. X 3 represents -O-, -CO-, -COO-, -OCO-, -CONH-, -NHCO- or -NH-. X 4 represents a linear or branched alkyl group having 12 to 40 carbon atoms.)(T A represents a hydrogen atom or a benzene ring. * represents a bond.

Description

Technical Field

[0001] This invention relates to a curable composition and its cured product. Background Technology

[0002] In display components and semiconductor components, various adhesives have traditionally been used for mounting various components within the components. The required properties of adhesives include: adhesion between the substrate and the component; as well as their processability and reliability.

[0003] Furthermore, the substrates to be bonded include organic substrates such as printed circuit boards and transparent polyimide films; and inorganic substrates such as glass, aluminum, ITO (Indium Tin Oxide), and SiN (Silicon Nitride). Therefore, the adhesive needs to be designed to be compatible with each of the target substrates.

[0004] To date, adhesives for display elements and semiconductor elements have used heat- or UV-curable resin components with epoxy curing systems or free radical curing systems (e.g., Patent Document 1 and Patent Document 2). The epoxy curing system uses highly reliable epoxy-based compounds, and the free radical curing system uses free radical polymerizable compounds.

[0005] As an epoxy curing system, there are resin components that include compounds having epoxy groups, epoxy resins, and curing catalysts that generate cationic catalysts using heat or light. On the other hand, free radical curing systems typically include resin components that include compounds having acrylate groups or the like that undergo free radical polymerization, their resins, and free radical initiators that generate free radicals using heat or ultraviolet light irradiation.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2010-229172

[0009] Patent Document 2: Japanese Patent Application Publication No. 2002-203427 Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] As optical components become thinner, the adhesive layer (also known as the bonding layer) used in them needs to be thinner. To achieve this thinner bonding layer, the thickness of the curable composition coated on the substrate also needs to be thinner. However, curable compositions using epoxy-based compounds to date are mostly high-viscosity compositions, which are prone to pitting and uneven coating when applied as thin films.

[0012] Furthermore, free radical curing compositions suffer from reduced curability of the adhesive layer due to the susceptibility of free radicals to oxygen hindrance. Moreover, compared to materials using epoxy groups, they exhibit greater curing shrinkage, leading to deformation and voids at the substrate-adhesive layer interface, thus reducing the adhesive strength (also known as adhesion) to the substrate.

[0013] Considering the above aspects, the object of the present invention is to provide a free radical curable composition with low viscosity, low curing shrinkage, and high adhesion.

[0014] Solution for solving the problem

[0015] In order to achieve the above objectives, the inventors conducted in-depth research and as a result completed the present invention with the following main points.

[0016] That is, a curable composition containing the following components (A) and (B).

[0017] (A) Components: Monofunctional radical polymeric compounds containing compounds (also known as specific compounds) as shown in the following formula [1].

[0018] (B) Component: Free radical initiator.

[0019] X 1 -X 2 -X 3 -X 4 [1]

[0020] (In formula [1], X) 1 X represents a structure selected from the following formulas [1-a] to [1-g]. 2 The alkylene group is a straight-chain alkylene group having 2 to 14 carbon atoms. Optionally, the alkylene group undergoes at least one of the following substitutions (i) and (ii): (i) substitution of the alkylene group with X. 1 or X 3 Any non-adjacent -CH2- is substituted with -O-, -CO-, -COO-, -OCO-, -CONH-, -NHCO-, -NH-, a benzene ring, or a cyclohexane ring. (ii): Any -CH2- in the above alkylene groups is substituted with -CH(CH3)-. X 3 This represents -O-, -CO-, -COO-, -OCO-, -CONH-, -NHCO-, or -NH-. X 4 (Refers to straight-chain or branched alkyl groups with 12 to 40 carbon atoms.)

[0021]

[0022] (T A* Represents a hydrogen atom or a benzene ring. * Represents a bonded bond.

[0023] Invention Effects

[0024] The curable composition of the present invention has low viscosity, thus it can be applied to various coating methods and can achieve uniform coating without film thickness unevenness. Furthermore, when the curable composition of the present invention is used as an adhesive for display elements and semiconductor elements, it exhibits low curing shrinkage and high adhesion, thereby suppressing deformation and void formation between the substrate and the adhesive layer, resulting in components with excellent reliability.

[0025] The mechanism by which the present invention can obtain a curable composition with the above-mentioned excellent properties may not be clear, but the following reasons can be inferred.

[0026] In the curable composition, a free radical-curable polymeric compound that reacts using free radicals is used. Therefore, this compound has a lower viscosity than epoxy-based compounds, resulting in a lower viscosity curable composition using this compound.

[0027] Furthermore, X in the above formula [1] in a specific compound 4 The structure consists of long-chain alkyl groups with a lower Tg in the cured product. Therefore, curable compositions containing specific compounds cure while maintaining a viscous state, resulting in improved adhesion to substrates and components. Furthermore, X 4 Due to the large volume of intermolecular exclusion, the structure can reduce curing shrinkage. Attached Figure Description

[0028] Figure 1A This is a top-down view of a schematic diagram of the test unit used for fit evaluation.

[0029] Figure 1B This is a schematic diagram of the test unit used for fit evaluation, viewed from the side.

[0030] Figure 2A This is a schematic diagram of the U-shaped upper clamp used for fit evaluation.

[0031] Figure 2B This is a schematic diagram of the U-shaped lower clamp used for fit evaluation.

[0032] Figure 3 This is a top-down view of the test unit, illustrating the area where the test unit contacts the U-shaped fixture during the fit evaluation. Detailed Implementation

[0033] The present invention will now be described in detail.

[0034] The curable composition of the present invention contains the following components (A) and (B).

[0035] (A) Components: Monofunctional free radical polymeric compounds containing the compounds shown in the above formula [1].

[0036] (B) Component: Free radical initiator.

[0037] In addition, another embodiment of the present invention is the compound shown in the above formula [1].

[0038] <(A)Component>

[0039] (A) A monofunctional radical polymeric compound whose constituents are compounds (also called specific compounds) as essential components as shown in the above formula [1]. Here, a monofunctional radical polymeric compound refers to a compound having a functional group in its molecule that reacts using a free radical.

[0040] In formula [1], X 1 X 2 X 3 and X 4 As defined above, the preferred conditions are as follows.

[0041] From the perspective of improving the reactivity of free radical reactions, X 1 The preferred structure is the one shown in formula [1-a], formula [1-b], formula [1-c] or formula [1-d].

[0042] X 2 Preferably, it has the structure shown in the following formula [X1a].

[0043]

[0044] (In formula [X1a], M) 1 and M 2 Each can be represented independently as -CH2-CH2-, -CH(CH3)-CH2-, or -CH2-CH(CH3)-. Z 1 Represents -O-, -CO-, -COO-, or -OCO-. n represents an integer from 0 to 4. When n is an integer greater than 2, there are n Z... 1 and M 2 Each has the above definition independently. *1 indicates that it is related to X. 1 The bonding position, *2 indicates the position with X. 3 (The bonding location.)

[0045] X 3 Preferably, it is -O-, -CO-, -COO-, or -OCO-.

[0046] From the perspective of reducing the Tg of the solidified product and increasing the intermolecular clearance volume, X 4Preferably, it is a branched alkyl group with 12 to 40 carbon atoms.

[0047] Among them, the specific compound is further preferably the compound shown in the following formula [1a].

[0048]

[0049] (In equation [1a], R) 1 This indicates a hydrogen atom or a methyl group. L 1 and L 2 Each can be represented independently as -CH2-CH2-, -CH(CH3)-CH2-, or -CH2-CH(CH3)-. 1 This represents -O-, -CO-, -COO-, or -OCO-. n represents an integer from 0 to 4. When n is an integer greater than 2, n Y... 1 and L 2 Each possesses the above definition independently. Y 2 Indicates -COO- or -OCO-. L 3 Represents a single bond or a straight-chain or branched alkylene group having 1 to 4 carbon atoms. R 2 and R 3 Each of the following independently represents a straight-chain or branched alkyl group having 4 to 18 carbon atoms. R 4 Alkyl groups, representing straight-chain or branched alkyl groups having 1 to 18 hydrogen or carbon atoms. In L... 3 When L represents a group other than a single bond, 3 and R 2 ~R 4 The total number of carbon atoms ranges from 11 to 39 in L. 3 In the case of a single bond, R 2 ~R 4 The total number of carbon atoms ranges from 11 to 39.

[0050] As specific compounds, the compounds shown in formulas [A1] to [A5] below can be listed, and they are preferred to be used.

[0051]

[0052] Furthermore, from the viewpoint of adjusting the liquid properties of the curable composition and the film properties of the cured product, component (A) may also contain monofunctional free radical polymerizable compounds other than specific compounds.

[0053] Examples of monofunctional free radical polymerizable compounds other than specific compounds include: 2-ethylhexyl acrylate, 1-butylethyl acrylate, 2-butoxyethyl acrylate, 2-cyanoethyl acrylate, benzyl acrylate, cyclohexyl acrylate, 2-hydroxypropyl acrylate, 2-ethoxyethyl acrylate, N,N-diethyl-2-aminoethyl acrylate, N,N-dimethyl-2-aminoethyl acrylate, dicyclopentanyl acrylate, and dicyclopentenyl acrylate. acrylate), glycidyl acrylate, tetrahydrofurfuryl acrylate, isobornyl acrylate, isodecyl acrylate, lauryl acrylate, 4-acryloylmorpholine, 2-phenoxyethyl acrylate, diethylene glycol phenyl ether, 2,2,2-trifluoroethyl acrylate, 2,2,3,3,3-pentafluoropropyl acrylate, 2,2,3,3-tetrafluoropropyl acrylate, 2,2,3,4,4,4-hexafluorobutyl acrylate, 2-ethylhexyl methacrylate, 1-butylethyl methacrylate, 2-butoxyethyl methacrylate, 2-cyanoethyl methacrylate, benzyl methacrylate, cyclohexyl methacrylate, 2-hydroxypropyl methacrylate, 2-ethoxy acrylate N,N-diethyl-2-aminoethyl methacrylate, N,N-dimethyl-2-aminoethyl methacrylate, dicyclopentyl methacrylate, dicyclopentadienyl methacrylate, glycidyl methacrylate, tetrahydrofurfuryl methacrylate, isobornyl methacrylate, isodecanyl methacrylate, lauryl methacrylate, 4-methacryloylmorpholine, 2-phenoxyethyl methacrylate, diethylene glycol phenyl ether methacrylate, 2,2,2-trifluoroethyl methacrylate, 2,2,3,3-tetrafluoropropyl methacrylate, 2,2,3,4,4,4-hexafluorobutyl methacrylate, nonylphenol EO-modified acrylate, nonylphenol EO-modified methacrylate.

[0054] More specifically, examples include: NK esters A-LEN-10, AM-90G, AM-130G, AMP-20GY, A-SA, S-1800A, CB-1, M-90G, M-230G, PHE-1G, S, SA (all manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), Aronix M-111, M-120, M-140 (all manufactured by Toa Synthetic Co., Ltd.), etc.

[0055] In addition to the above-mentioned monofunctional free radical polymerizable compounds, considering the curability and curing shrinkage of the adhesive layer, monofunctional aromatic urethane acrylates and aliphatic urethane acrylates may also be included.

[0056] In addition to the above-mentioned monofunctional free radical polymerizable compounds, compounds with intramolecular thiol groups may also be included from the perspective of the adhesion between the adhesive layer and the substrate. Specifically, examples include: 1-decathiol, 1-dodecathiol, 1-hexadecathiol, 1-octylthiol, 1-octadecathiol, etc.

[0057] Furthermore, as a monofunctional free radical polymerizable compound other than those mentioned above, it is preferable to include a compound containing an intramolecular phosphate group for the purpose of improving the adhesion between the adhesive layer and the substrate. Specifically, examples of monofunctional free radical polymerizable compounds containing an intramolecular phosphate group include: Phosmer M, PE, PP (the above, manufactured by Uni-chemical Co., Ltd.), lightacrylate P-1A(N), and lightester P-1M (the above, manufactured by Kyoeisha Chemical Co., Ltd.).

[0058] In component (A), only the specific compound may be used, or two or more specific compounds may be used in combination. Furthermore, one or more specific compounds and one or more monofunctional radical polymerizable compounds other than the specific compound may be used in combination. Regarding the ratio of the specific compound to the monofunctional radical polymerizable compounds other than the specific compound in component (A), when component (A) is 100 parts by mass, it is preferable to include 10 parts by mass or more of the specific compound.

[0059] <(B) Component>

[0060] (B) In the composition, thermal free radical initiators that generate free radicals using heat and photofree radical initiators that generate free radicals using ultraviolet light can be used. These initiators should be appropriately selected according to the curing process of the curable composition.

[0061] Examples of thermal free radical initiators that utilize heat to generate free radicals include compounds having ketone peroxide, peroxyketal, hydroperoxide, dialkyl peroxide, diacyl peroxide, peroxide ester, peroxide dicarbonate, or azo compounds. It should be noted that if a thermal free radical initiator that generates gas upon free radical generation is used, voids may sometimes be created. Therefore, compounds having ketone peroxide, peroxyketal, hydroperoxide, dialkyl peroxide, diacyl peroxide, peroxide ester, or peroxide dicarbonate structures are preferred as thermal free radical initiators.

[0062] Specifically, the following can be listed: diisobutyryl peroxide, cumyl peroxyneodecanoate, di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, di-sec-butyl peroxydicarbonate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, bis(4-tert-butylcyclohexyl) peroxydicarbonate, bis(2-ethylhexyl) peroxydicarbonate, tert-hexyl peroxyneodecanoate, tert-butyl peroxyneodecanoate, tert-butyl peroxyneoheptanoate, tert-hexyl peroxyneopentaate, tert-butyl peroxyneopentaate, bis(3,5,5-trimethylhexanoyl) peroxide, dilauroyl peroxide, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, and disuccinic acid peroxide. 2,5-Dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, tert-hexyl peroxide-2-ethylhexanoate, di(4-methylbenzoyl peroxide), tert-butyl peroxide-2-ethylhexanoate, benzoyl peroxide, 1,1-bis(tert-butylperoxy)-2-methylcyclohexane, 1,1-bis(tert-hexanoylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-hexanoylperoxy)cyclohexane, 1,1-bis(tert-butylperoxy)cyclohexane, 2,2-bis(4,4-di-(tert-butylperoxy)cyclohexyl)propane, tert-hexyl peroxide isopropyl monocarbonate, tert-butyl peroxide maleic acid, tert-butyl peroxy-3,5,5-trimethylhexanoate, tert-butyl peroxide laurate, tert-butyl peroxide isopropyl monocarbonate Carbonates, tert-butylperoxide-2-ethylhexyl monocarbonate, tert-hexyl peroxide benzoate, 2,5-dimethyl-2,5-bis(benzoylperoxy)hexane, tert-butyl peroxyacetate, 2,2-bis(tert-butylperoxy)butane, tert-butyl peroxybenzoate, n-butyl-4,4-bis(tert-butylperoxy)valerate, 1,4-bis(tert-butylperoxyisopropyl)benzene, dicumyl peroxide, di-tert-hexyl peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, tert-butyl peroxide, di-tert-butyl peroxide, p-menthol hydroperoxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)-3-hexyne, dicumyl peroxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide Hydroperoxide, as well as tert-butyl hydroperoxide, etc.

[0063] More specifically, PEROYL IB, PERCUMYL ND, PEROYL NPP, PEROYL IPP, PEROYL SBP, PEROYL ND, PEROYL TCP, PEROYL OPP, PERHEXYL ND, PERBUTYL ND, PERBUTYLNHP, PERHEXYL PV, PERBUTYL PV, PEROYL 355, PEROYL L, PEROCTA O, PEROYL SA, PERHEXA25O, PERHEXYL O, NYPER PMB, PERBUTYL O, NYPER BMT, NYPER BW, PERHEXA MC, PERHEXATMH, PERHEXA HC, PERHEXA C, PERTETRA A, PERHEXYL I, PERBUTYL MA, PERBUTYL 355, PERBUTYL L, PERBUTYL I, PERBUTYL E.PERHEXYL Z.PERHEXA 25Z, PERBUTYL A, PERHEXA22, PERBUTYL Z, PERHEXA V, PERBUTYL P, PERCUMYL D, PERHEXYL D, PERHEXA 25B, PERBUTYL C, PERBUTYL D, PERMENTA H, PERHEXYNE 25B, PERCUMYL P, PEROCTA H, PERCUMYL H, PERBUTYL H, or NOFMER BC (all manufactured by Nippon Oil Company), etc.

[0064] Considering reactivity and reaction initiation temperature, the following are preferred: bis(4-tert-butylcyclohexyl) peroxydicarbonate (PEROYL TCP / Nippon Oil Co., Ltd.), tert-butyl peroxypentanoate (PERBUTYL PV / Nippon Oil Co., Ltd.), 1,1,3,3-tetramethyl butyl peroxy-2-ethylhexanoate (PEROCTA O / Nippon Oil Co., Ltd.), 1,1-bis(tert-hexylperoxy)cyclohexane (PERHEXA HC / Nippon Oil Co., Ltd.), 2,5-dimethyl-2,5-di(benzoylperoxy)hexane (PERHEXA 25Z / Nippon Oil Co., Ltd.), tert-butyl peroxybenzoate (PERBUTYL Z / Nippon Oil Co., Ltd.), and 1,4-bis(tert-butylperoxyisopropyl)benzene (PERBUTYL P / Nippon Oil Co., Ltd.).

[0065] From the perspective of the storage stability and curability of the curable composition, the proportion of the thermal free radical initiator used is preferably 0.01 to 10 parts by mass relative to 100 parts by mass of the total free radical polymerizable compound containing component (A). More preferably, it is 0.05 to 5 parts by mass. Furthermore, based on the above characteristics, one or more of these thermal free radical initiators can also be used in combination.

[0066] Examples of photoradical initiators that utilize ultraviolet light to generate free radicals include: 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxycyclohexylphenyl one, 2-hydroxy-2-methyl-1-phenylpropane-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methylpropane-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropanoyl)-benzyl]phenyl}-2-methylpropane-1-one, 2-methyl-1-(4-methylthiophenyl)-2-morpholinylpropane-1-one, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, 2,4,6-Trimethylbenzoyl diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 1-[4-(phenylthio)phenyl]octane-1,2-dione = 2-(O-benzoyl oxime)], 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-ethyl ketone = 1-(O-acetyl oxime), methyl benzoylformate, a mixture of 2-[2-oxo-2-phenyl-acetoxy-ethoxy]ethyl ester and 2-hydroxyphenylacetic acid-2-[2-hydroxy-ethoxy]ethyl ester, or 2-benzyl-2-(dimethylamino)-1-[4-(4-morpholino)phenyl]-1-butanone, etc.

[0067] More specifically, the following can be listed: Omnirad 1173, 184, 127, 2959, 369, 379, 389, 907, 4265, 1000, 651, TPO-H, TPO-L, 819, 819DW, 2022, 2100, 754, OXE-01, OXE-02, OXE-03, OXE-04, BPFlakes, 4MBZFlakes, OMBB, 1601, BMS, ITX, DETX, BBF, EMK, EsacureKIP150, KIP100F, or TZT, etc. (all from IGM Resins).

[0068] Considering reactivity and wavelength selectivity, the following are preferred: 1-hydroxycyclohexylphenyl ketone (manufactured by Omnirad 184 / IGM Resins), 2-hydroxy-2-methyl-1-phenylpropane-1-one (manufactured by Omnirad 1173 / IGM Resins), 2-benzyl-2-(dimethylamino)-1-[4-(4-morpholino)phenyl]-1-butanone (manufactured by Omnirad 369 / IGM Resins), 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropane-1-one (manufactured by Omnirad 907 / IGM Resins), bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (manufactured by Omnirad 819 / IGM Resins), and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (Omnirad TPO-H / IGM). (manufactured by Resins), Omnirad TPO-L / IGM Resins, 1-[4-(phenylthio)phenyl]octane-1,2-dione=2-(O-benzoyl oxime)](O-acetyl oxime) (Omnirad OXE01 / IGM Resins), and 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-acetone=2,1-(O-acetyl oxime) (Omnirad OXE02 / IGM Resins).

[0069] From the perspective of the curability of the adhesive layer, the proportion of photoradical initiator used is preferably 0.01 to 10 parts by mass relative to 100 parts by mass of all free radical polymerizable compounds containing component (A). More preferably, it is 0.05 to 5 parts by mass. Furthermore, one or more of these photoradical initiators can be used in combination, depending on the wavelength of the light source used in the curing process and the curability of the adhesive layer.

[0070] <(C) Ingredients>

[0071] In this invention, from the perspective of curability and film strength of the adhesive layer, as component (C), it is preferable to use a difunctional or higher free radical polymerizable compound (hereinafter referred to as a multifunctional free radical polymerizable compound) having two or more functional groups that can react with free radicals within the molecule.

[0072] Specifically, the following are examples of multifunctional free radical polymeric compounds.

[0073] Examples include: 4,4'-biphenyl diacrylate, Stilbestrol diacrylate, 1,4-bisacryloyloxybenzene, 4,4'-bisacryloyloxydiphenyl ether, 4,4'-bisacryloyloxydiphenylmethane, 3,9-[1,1-dimethyl-2-acryloyloxyethyl]-2,4,8,10-tetraoxospiro[5,5]undecane, α,α'-bis[4-acryloyloxyphenyl]-1,4-diisopropylbenzene, 1,4-bisacryloyloxytetrafluorobenzene, 4,4'-Diacryloyloxyoctafluorobiphenyl, diethylene glycol diacrylate, 1,4-butanediol diacrylate, 1,3-butanediol diacrylate, glycerol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, tetraethylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, pentaerythritol triacrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol hexaacrylate, dipentaerythritol monohydroxy pentaacrylate, 4,4'-diacryloyloxystyrene, 4, 4'-Diacryloyloxydimethylstyrene, 4,4'-Diacryloyloxydiethylstyrene, 4,4'-Diacryloyloxydipropylstyrene, 4,4'-Diacryloyloxydibutylstyrene, 4,4'-Diacryloyloxydipentylstyrene, 4,4'-Diacryloyloxydihexylstyrene, 4,4'-Diacryloyloxydifluorostyrene, 2,2,3,3,4,4-Hexafluoropentanediol-1,5-diacrylate, 1,1,2,2,3,3-Hexafluoropropyl-1,3-diacrylate, dimethyl... Diethylene glycol acrylate, 1,4-butanediol dimethacrylate, 1,3-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, tetraethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetramethacrylate, pentaerythritol trimethacrylate, di(trimethylolpropane)tetramethacrylate, dipentaerythritol hexamethacrylate, dipentaerythritol monohydroxypentamethacrylate, 2,2,3,3,4,4-hexafluoropentanediol-1,5-Dimethacrylate, Tricyclodecanedimethylethanol diacrylate, Tricyclodecanedimethylethanol dimethacrylate, Dipropylene glycol diacrylate, Tripropylene glycol diacrylate, Polypropylene glycol #400 diacrylate, Polypropylene glycol #700 diacrylate, Dipropylene glycol dimethacrylate, Tripropylene glycol dimethacrylate, Polypropylene glycol #400 dimethacrylate, Polypropylene glycol #700 dimethacrylate, Polyethylene glycol #200 diacrylate Monomers and oligomers including polyethylene glycol #400 diacrylate, polyethylene glycol #600 diacrylate, polyethylene glycol #200 dimethacrylate, polyethylene glycol #400 dimethacrylate, polyethylene glycol #600 dimethacrylate, ethoxylated bisphenol A diacrylate, propoxylated bisphenol A diacrylate, ethoxylated bisphenol A dimethacrylate, propoxylated bisphenol A dimethacrylate, or ethoxylated pentaerythritol tetraacrylate.

[0074] More specifically, the following can be listed: NK ester 701A, A-200, A-400, A-600, A-1000, A-B1206PE, ABE-300, A-BPE-10, A-BPE-20, A-BPE-30, A-BPE-4, A-BPEF, A-BPP-3, A-DCP, A-DOD-N, A-HD-N, A-NOD-N, APG-100, APG-200, APG-400, APG-700, A-PTMG-65, A-9300, A-9300-1CL, A-GLY-9E, A-GLY-20E, A-TMM-3, A-TMM-3L, A -TMM-3LM-N, A-TMPT, AD-TMP, ATM-35E, A-TMMT, A-9550, A-DPH, 1G, 2G, 3G, 4G, 9G, 14G, 23G, BPE-80N, BPE-100, BPE-200, BPE-500, BPE-900, BPE-1300N, DCP, DOD-N, HD-N, NOD-N, NPG, 1206PE, 701, 9PG, TMPT (all manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), KAYARADFM-400, HX-220, HX-620, R-712 (all manufactured by Nippon Kayaku Co., Ltd.), BLEMMER PDE-100, PDE-200, PDE-400, PDP-400N, ADE-200, ADE-300, ADE-400A or ADP-400 (and above, manufactured by Nippon Oil Company), etc.

[0075] Among these, considering the film strength and curing shrinkage of the adhesive layer, the preferred materials are tricyclodecanedimethylethanol diacrylate, tricyclodecanedimethylethanol dimethacrylate, polyethylene glycol #200 diacrylate, polyethylene glycol #400 diacrylate, polyethylene glycol #600 diacrylate, polyethylene glycol #200 dimethacrylate, polyethylene glycol #400 dimethacrylate, polyethylene glycol #600 dimethacrylate, tripropylene glycol diacrylate, polypropylene glycol #400 diacrylate, polypropylene glycol #700 diacrylate, tripropylene glycol dimethacrylate, polypropylene glycol #400 dimethacrylate, polypropylene glycol #700 dimethacrylate, ethoxylated bisphenol A diacrylate, ethoxylated bisphenol A dimethacrylate, KAYARADFM-400, HX-220, and HX-620 (all manufactured by Nippon Kayaku Co., Ltd.).

[0076] (C) In terms of curability and curing shrinkage of the adhesive layer, it is preferable to include aromatic urethane polyfunctional acrylates and aliphatic urethane polyfunctional acrylates. Specifically, the following models can be listed: EBECRYL210, 220, 230, 270, 4858, 8402, 8804, 8807, 9270, 4513, 4738, 4740, 8311, 9260, 8701, 4265, 4587, 4666, 8210, 1290, 5129, 8301R, 4501, 2221, 1271, 4859, 8409, 8465, 8809, 8810, 8811, 4101, 4201, 8209, 1291, 8602, 225, KRM8191, 8667, 8296, 8200, 8904, or 8452 (all of which are manufactured by Daicel Allnex).

[0077] From the perspective of the transparency of the adhesive layer, EBECRYL230, 4858, 8402, 8804, 8807, 4859, 8465, 8809 and 8811 (all of which are manufactured by Daicel Allnex) containing aliphatic urethane polyfunctional acrylates are preferred.

[0078] Furthermore, in component (C), from the perspective of the adhesion between the adhesive layer and the substrate, it is preferable to include a polyfunctional free radical polymerizable compound with an intramolecular thiol group. Specifically, examples include: trimethylolpropane tris(3-mercaptopropionate), tris-[(3-mercaptopropoxy)-ethyl]-isocyanurate, pentaerythritol tetra(3-mercaptopropionate), tetraethylene glycol bis(3-mercaptopropionate), dipentaerythritol hexa(3-mercaptopropionate), trimethylolpropane tris(3-mercaptobutyrate), trimethylolethane tris(3-mercaptobutyrate), pentaerythritol tetra(3-mercaptobutyrate), 1,3,5-tris(3-mercaptobutoxyethyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, neopentanetetrathiol, pentaerythritol tetra(3-mercaptopropionate), and dipentaerythritol hexa(3-mercaptopropionate), etc. More specifically, examples include: KarenzMTPE1, BD1, NR1, and TPMB (all manufactured by Showa Denko). Among these, Karenz MTPE1, BD1, and NR1 (all manufactured by Showa Denko) are preferred.

[0079] The proportion of the polyfunctional free radical polymerizable compound having a thiol group in the molecule is preferably 0.05 to 10 parts by mass relative to the total 100 parts by mass of components (A) and (C), and more preferably 0.1 to 5 parts by mass.

[0080] It should be noted that compounds with thiol groups function as chain transfer agents in free radical polymerization. Furthermore, residues of compounds with one thiol group within the molecule are typically present at the ends of the polymer chain, similar to initiators. However, when using compounds with two or more thiol groups within the molecule, they not only function as chain transfer agents but also generate growth reactions from these two or more thiol groups, resulting in residues of the compound being present in the middle of the polymer chain. Moreover, when using compounds with three or more thiol groups within the molecule, growth reactions occur from these three or more thiol groups, resulting in residues of the compound also serving as crosslinking points for the polymer chain. Therefore, in this invention, compounds with two or more thiol groups within the molecule are included in multifunctional free radical polymerizable compounds.

[0081] Furthermore, to improve the adhesion between the adhesive layer and the substrate, polyfunctional free radical polymeric compounds with phosphate groups within their molecules can also be used. Specifically, examples include KAYAMER PM-2 or PM-21 (both manufactured by Nippon Kayaku Co., Ltd.).

[0082] The proportion of the polyfunctional free radical polymerizable compound containing phosphate groups within the molecule is preferably 0.01 to 3 parts by mass relative to a total of 100 parts by mass of components (A) and (C), and more preferably 0.05 to 2 parts by mass.

[0083] (C) In the composition, one or more of these multifunctional free radical polymerizable compounds may be mixed together.

[0084] <Curing Composition>

[0085] The curable composition contains component (A) and component (B). In this case, component (C) may also be included, considering the curability and film strength of the adhesive layer.

[0086] The proportion of component (A) in the case containing components (A) and (C) is preferably 10 to 99 parts by mass relative to a total of 100 parts by mass of components (A) and (C). More preferably, it is 20 to 95 parts by mass, and even more preferably, it is 40 to 90 parts by mass. Furthermore, component (C) preferably comprises 1 part by mass or more relative to a total of 100 parts by mass of components (A) and (C). More preferably, it comprises 5 parts by mass or more, and even more preferably, it is 10 parts by mass or more. Furthermore, the proportion of component (C) in the case containing components (A) and (C) is preferably 90 parts by mass or less relative to a total of 100 parts by mass of components (A) and (C), more preferably 80 parts by mass or less, and even more preferably 60 parts by mass or less.

[0087] Furthermore, the proportion of the compound shown in formula [1] above, containing components (A) and (C), is preferably 10 to 99 parts by mass relative to a total of 100 parts by mass of components (A) and (C). More preferably, it is 20 to 95 parts by mass, and even more preferably, it is 40 to 90 parts by mass.

[0088] For the curable composition, it is preferable to adjust the mixing ratio of components (A), (B), and (C) to achieve a viscosity of 1–10000 mPa·s at 25°C. It should be noted that, for applicability to the various coating methods described below, a viscosity of 1–500 mPa·s at 25°C is preferred. More preferably, 1–300 mPa·s, and even more preferably 1–100 mPa·s, from the perspective of maintaining dimensional control and reducing unevenness during coating or curing of the curable composition.

[0089] Methods for preparing curable compositions include: mixing components (A), (B), and (C) together; and mixing component (B) into a substance in which components (A) and (C) have been mixed beforehand.

[0090] Solvents can also be added to the curing composition to produce a varnish-like consistency. This improves the coatability and processability of the substrate. As a solvent, there are no particular limitations; any known solvent can be used as long as components (A), (B), and (C) are uniformly dissolved. Specifically, examples include: methanol, ethanol, isopropanol, acetone, toluene, tetrahydrofuran, hexane, ethyl acetate, 1-butanol, 2-methoxyethanol, 2-ethoxyethanol, cyclohexanone, propylene glycol monomethyl ether acetate, N-methyl-2-pyrrolidone, and γ-butyrolactone. One or more of these can be mixed. Where it is necessary to reduce the generation of gases from the solvent, it is preferable not to add any solvent.

[0091] The curing composition may also contain inorganic or organic fillers. Among these, inorganic fillers are preferred for improving the heat resistance of the adhesive layer. Well-known inorganic fillers include, for example, aluminum hydroxide, magnesium hydroxide, boron nitride, crystalline silica, and amorphous silica. One or more of these fillers may be used in combination.

[0092] Spacers can also be introduced into the curing composition to control the gaps in the adhesive layers (also known as gaps).

[0093] Curable compositions can be used, for example, as adhesives.

[0094] The cured product of the present invention is obtained from the curable composition or adhesive of the present invention. The cured product is obtained, for example, by curing the curable composition described later.

[0095] <Method for making adhesive layer>

[0096] The curable composition can be used as an adhesive for bonding substrates to each other, bonding components to substrates, or bonding liquid crystal display elements or organic EL elements to each other. Examples of bonding methods include: applying the curable composition to the bonding surface of one substrate, bonding another substrate or component to the bonding surface of the substrate, and then curing the curable composition. Furthermore, when using the curable composition of the present invention as an adhesive, from an environmental, safety, and health perspective, the adhesive can also be a solvent-free adhesive that is substantially solvent-free. Here, "substantially solvent-free" means containing 0 to 0.5 parts by weight, preferably 0 to 0.2 parts by weight, of solvent in 100 parts by weight of the total amount of the curable composition. Moreover, the curable composition of the present invention can also be applied and cured to serve as a cured film such as an insulating film.

[0097] Methods for applying a curable composition to a substrate include spin coating, slot coating, roller coating, inkjet coating, screen printing, bar coating, flexographic printing, gravure printing, die coating, and dispensing. These methods are appropriately selected based on the type of substrate and the desired thickness of the adhesive layer. The curable composition of this invention, due to its low viscosity, is best suited for inkjet coating.

[0098] The curing treatment of the curable composition should be appropriately selected according to the type of free radical initiator.

[0099] When using a curable composition with a thermal free radical initiator, the following methods can be employed. The curable composition is coated using the above method, and then substrates are bonded together, or components are attached to the substrates, followed by heat treatment. Examples of heating equipment used in this process include heating plates, thermal circulation ovens, and IR (infrared) ovens. Since the presence of oxygen will hinder curing, it is preferable to use an oxygen-free environment such as a nitrogen atmosphere or vacuum. Furthermore, it is preferable to press the substrates together or the substrates to the components during heat treatment.

[0100] When using a curable composition with a photoradical initiator, the following methods can be employed. After applying the curable composition using the above method, it is bonded to another substrate or a component and then irradiated with ultraviolet light. As described above, this is preferably done under a nitrogen atmosphere or vacuum. Furthermore, to improve the accuracy of bonding or adhesion, the following method can be used: as a temporary curing step, after applying the curable composition, the coated layer of the curable composition is irradiated with ultraviolet light, then bonded to another substrate or a component, followed by a formal curing treatment. The ultraviolet irradiation for the temporary curing step is preferably performed under atmospheric conditions. Furthermore, as a formal curing treatment, ultraviolet irradiation or heat treatment can be employed. The amount of ultraviolet irradiation and the temperature of the heat treatment are appropriately selected depending on the type of substrate and the type of photoradical initiator. Ultraviolet irradiation and heat treatment are preferably performed under a nitrogen atmosphere. The oxygen concentration can be controlled to be less than 100 mg / L.

[0101] The lower the curing shrinkage rate of the curable composition of the present invention compared to the uncured state, the better. In this embodiment, it is preferably 9.0% or less, and more preferably 8.5% or less.

[0102] The curing shrinkage rate can be determined using the method described in "Evaluation of Curing Shrinkage Rate" below.

[0103] Examples of light sources for ultraviolet irradiation devices include metal halide lamps, high-pressure mercury lamps, and LED light sources. In this case, the wavelength of the ultraviolet light is preferably 250–450 nm. More preferably, it is 310–400 nm.

[0104] From the perspective of improving productivity, the optimal ultraviolet irradiance is set to 1–50 mW / cm². 2 The range. From the viewpoint of complete curing, the ultraviolet irradiation dose is preferably set to 50 mJ / cm. 2 ~30000mJ / cm 2 The range.

[0105] Examples of substrates that can be used as adherents include: oxides / nitrides (e.g., quartz, glass, silicon dioxide, titanium dioxide, alumina, sapphire, aluminosilicate glass, borosilicate glass, silicon nitride, SiON, ITO, IZO, and IGZO), plastics (e.g., polymethyl methacrylate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, ABS, polycarbonate, polystyrene, epoxy, unsaturated polyester, melamine, diallyl phthalate, polyamide, etc.). Substrates and films of imides, urethanes, nylon, polyethylene, polypropylene, cyclic olefin polymers, polyvinyl chloride, fluoropolymers (polytetrafluoroethylene resin, polychlorotrifluoroethylene resin, polyvinylidene fluoride resin, polyvinyl fluoride resin, perfluoroalkoxy fluoropolymer, tetrafluoroethylene / hexafluoropropylene copolymer resin, ethylene / tetrafluoroethylene copolymer resin, ethylene / chlorotrifluoroethylene copolymer resin, etc.), polybutadiene, polyisoprene, SBR, nitrile rubber, EPM, EPDM, epichlorohydrin rubber, chloroprene rubber, polysulfides, butyl rubber, cellulose, cellulose derivatives and cellulose analogs, etc.), and metals (e.g., iron, aluminum, stainless steel, titanium, gold, silver, copper, zinc, molybdenum and their alloys, etc.).

[0106] For optical applications, among oxides / nitrides, glass, silicon dioxide, alumina, aluminosilicate glass, borosilicate glass, silicon nitride, SiON, and ITO are preferred. Among plastics, polymethyl methacrylate, polyethylene terephthalate, polycarbonate, and polyimide are preferred. Among metals, aluminum, silver, copper, molybdenum, and their alloys are preferred.

[0107] The optical element of the present invention is obtained using the curable composition of the present invention.

[0108] Furthermore, the optical elements of the present invention are obtained using the adhesive of the present invention.

[0109] Curable compositions can also be preferably used as sealing materials for electronic devices. Examples of electronic devices include organic electroluminescent (EL) elements, organic thin-film solar cells, and light-emitting diode (LED) elements. Known methods can be used as sealing methods for electronic devices. Specifically, the curable composition can be applied to a substrate or component using spin coating or inkjet printing, and then cured by heat treatment or ultraviolet light irradiation to seal the electronic device.

[0110] Furthermore, the curable composition can also be used as an adhesive for bonding acrylic sheets, transparent polyimide resins, and other plastic sheets, as well as touch panel sensors, to liquid crystal display elements, organic EL displays, quantum dot displays, etc. It can also be used when bonding display elements such as liquid crystal display elements, organic EL displays, and quantum dot displays to each other.

[0111] Example

[0112] The following examples illustrate the invention in further detail, but are not intended to limit it.

[0113] [Synthesis of specific compounds]

[0114] A1 to A5 are novel compounds not disclosed in the literature. The synthesis method is described in detail below.

[0115] The products (A1-A5) described in Examples 1-5 below are obtained through... 1 H-NMR analysis for identification (analytical conditions as follows).

[0116] Device: BRUKER ADVANCE III – 500MHz.

[0117] Solvents used for determination: DMSO-d6, CDCl3.

[0118] Reference material: Tetramethylsilane (TMS) (δ 0.0 ppm for 1 H).

[0119] The abbreviations used in this invention have the following meanings.

[0120] EDC·HCl: 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride.

[0121] DMAP: 4-Dimethylaminopyridine.

[0122] <Example 1: Synthesis of a specific compound (A1)>

[0123]

[0124] 2,2,4,8,10,10-hexamethylundecane-5-carboxylic acid (30.0 g, 105 mmol), dichloromethane (78 g), EDC·HCl (23.0 g, 120 mmol), and DMAP (1.22 g, 9.99 mmol) were added to 2-hydroxyethyl methacrylate (13.0 g, 99.9 mmol), and the mixture was stirred at 25 °C for 20 hours. After the reaction was complete, stirring was stopped, and water (80 g) was added for separation and washing. The mixture was then separated and washed with saturated sodium bicarbonate aqueous solution (80 g) and water (80 g). The organic layer was concentrated to give a pale yellow oil. The oil was purified by column chromatography (developing solvent: heptane / ethyl acetate = 4 / 1 (v / v)) to remove the solvent, thereby giving a specific compound (A1) (yield: 37 g, 93.3 mmol, yield: 98%).

[0125] 1 H-NMR (500MHz / DMSO-d6): δ (ppm) = 6.03 (s, 1H), 5.69 (s, 1H), 4.35-4.20 (m, 4H), 2.18-2.11 (m, 1H), 1.87 (s, 3H), 1.79-0.72 (m, 34H).

[0126] <Example 2 Synthesis of a specific compound (A2)>

[0127]

[0128] To polyethylene glycol monomethacrylate (trade name: BLEMMER PE-90, manufactured by Nippon Oil Company) (16.0 g, 91.8 mmol), 2,2,4,8,10,10-hexamethylundecane-5-carboxylic acid (26.4 g, 92.8 mmol), dichloromethane (96 g), EDC·HCl (26.4 g, 138 mmol), and DMAP (1.12 g, 9.17 mmol) were added, and the mixture was stirred at 25 °C for 10 days. After the reaction was complete, stirring was stopped, and the mixture was washed with water (96 g), followed by separation with saturated sodium bicarbonate aqueous solution (96 g), and then with water (96 g). The organic layer was concentrated to give a pale yellow oil. Purification was performed by column chromatography (developing solvent: ethyl acetate) to remove the solvent, thereby giving a specific compound (A2) (yield: 35 g, 79.4 mmol, yield: 87%).

[0129] 1H-NMR (500MHz / DMSO-d6): δ (ppm) = 6.03 (s, 1H), 5.69 (m, 1H), 4.39-4.05 (m, 4H), 3.70-3.45(m, 4H), 2.30-2.09(m, 2H), 1.88(s, 3H), 1.80-0.72(m, 33H).

[0130] <Example 3 Synthesis of a specific compound (A3)>

[0131]

[0132] Succinic anhydride (30.0 g, 300 mmol), ethyl acetate (240 g), pyridine (26.0 g, 325 mmol), and DMAP (1.80 g, 14.8 mmol) were added to 2-(4,4-dimethyl-2-pentenyl)-5,7,7-trimethyl-1-octanol (40.0 g, 148 mmol), and the mixture was stirred at 90 °C for 5 hours. After stopping stirring and cooling to 25 °C, the mixture was washed three times with water (120 g) to concentrate the organic layer, yielding an oil and a mixture of white crystals. Heptane (230 g) was added to the mixture, and the mixture was stirred at 25 °C for 30 minutes and filtered to remove the white crystals. The filtrate was washed twice with 1 N hydrochloric acid (230 g) to concentrate / dry the organic layer, yielding compound (1) (yield: 54 g, 146 mmol, 99%).

[0133] 1 H-NMR (500MHz / DMSO-d6): δ (ppm) = 12.2 (s, 1H), 4.00-3.83 (m, 2H), 2.53-2.53 (m, 4H), 1.62-1.73 (m, 1H), 1.49-0.72 (m, 34H).

[0134] Next, 2-hydroxyethyl methacrylate (19.3 g, 148 mmol), dichloromethane (326 g), EDC·HCl (33.7 g, 176 mmol), and DMAP (1.80 g, 14.7 mmol) were added to compound (1) (54.0 g, 146 mmol), and the mixture was stirred at 25 °C for 21 hours. After the reaction was complete, stirring was stopped, and the mixture was washed separately with water (326 g) and saturated brine (54 g). The mixture was then washed twice with saturated sodium bicarbonate aqueous solution (272 g) and saturated brine (109 g), and the organic layer (containing a portion of the aqueous layer) was concentrated. Heptane (320 g) was added, and the mixture was extracted separately, and the organic layer was concentrated again. The mixture was purified by column chromatography (developing solvent: heptane / ethyl acetate = 4 / 1 (v / v)) to remove the solvent, thereby obtaining the specific compound (A3) (yield: 57 g, 118 mmol, yield: 80%).

[0135] 1 H-NMR (500MHz / DMSO-d6): δ (ppm) = 6.03 (s, 1H), 5.67 (s, 1H), 4.27 (s, 4H), 3.97-3. 85(m, 2H), 2.56-2.54(m, 4H), 1.87(s, 3H), 1.70-1.60(m, 1H), 1.49-0.72(m, 34H).

[0136] <Example 4 Synthesis of a specific compound (A4)>

[0137]

[0138] 2-Hexyldecanoic acid (40.0 g, 156 mmol), dichloromethane (240 g), EDC·HCl (29.9 g, 156 mmol), and DMAP (1.59 g, 13.0 mmol) were added to 2-hydroxyethyl methacrylate (16.9 g, 130 mmol), and the mixture was stirred at 25 °C for 4 days. After the reaction was complete, stirring was stopped, and water (80 g) was added for separation and washing, and the organic layer was concentrated. Heptane (240 g) was added, and the mixture was separated and washed with saturated sodium bicarbonate aqueous solution (240 g), dimethyl sulfoxide (240 g), and water (240 g), respectively, and the organic layer was concentrated. The obtained oil was purified by column chromatography (developing solvent: heptane / ethyl acetate = 4 / 1 (v / v)) to remove the solvent, thereby obtaining a specific compound (A4) (yield: 46 g, 124 mmol, yield: 95%).

[0139] 1H-NMR (500MHz / CDCl3): δ (ppm) = 6.13 (s, 1H), 5.58 (s, 1H), 4.34-4.32 (m, 4H), 2.39-2.32 (m, 1 H), 1.94 (s, 3H), 1.65-1.57 (m, 2H), 1.45-1.43 (m, 2H), 1.31-1.09 (m, 20H), 0.88-0.87 (m, 6H).

[0140] <Example 5 Synthesis of a mixture of specific compounds (A5)>

[0141]

[0142] To 2-hydroxyethyl methacrylate (15.2 g, 117 mmol), a mixture of 2-octyldecanoic acid and 2-hexyldodecanoic acid (trade name: isostearic acid T, manufactured by Nissan Chemical Co., Ltd.) (40.0 g, 141 mmol), dichloromethane (240 g), EDC·HCl (27.0 g, 141 mmol), and DMAP (1.43 g, 11.7 mmol) were added, and the mixture was stirred at 25 °C for 24 hours. After the reaction was complete, stirring was stopped, and water (240 g) was added for separation and washing, and the organic layer was concentrated. Heptane (240 g) was added, and the mixture was separated and washed in the following order: saturated sodium bicarbonate aqueous solution (240 g), dimethyl sulfoxide (240 g), and water (240 g), and the organic layer was concentrated. The oil was purified by column chromatography (developing solvent: heptane / ethyl acetate = 4 / 1) and solvent was removed to obtain a mixture of specific compounds (A5) (yield: 42 g, 106 mmol, yield: 91%).

[0143] 1 H-NMR (500MHz / CDCl3): δ (ppm) = 6.12 (s, 1H), 5.58 (s, 1H), 4.35-4.34 (m, 4H), 2.39-2.32 (m, 1 H), 1.95 (s, 3H), 1.67-1.57 (m, 2H), 1.45-1.43 (m, 2H), 1.31-1.11 (m, 24H), 0.89-0.86 (m, 6H).

[0144] [Compounds used in the preparation of curable compositions]

[0145] <Specific Compound>

[0146] A1 to A5: These are the compounds and mixtures obtained in the above examples, respectively.

[0147] <Monofunctional radical polymeric compounds other than specific compounds>

[0148] A6: Aronix M-111 (nonylphenol EO modified acrylate) (manufactured by Dong-A Synthetic Co., Ltd.)

[0149] <Free radical initiators>

[0150] B1: PERHEXA 25Z (manufactured by Nippon Oil Company) / thermal free radical initiator.

[0151] B2: Omnirad TPO-H (manufactured by IGM Resins) / Photoradical initiator.

[0152] B3: OmniradOXE01 (manufactured by IGM Resins) / Photoradical initiator.

[0153] <Difunctional or higher free radical polymerizable compounds>

[0154] C1: BLEMMER PDE-200 (polyethylene glycol #200 dimethacrylate) (manufactured by Nippon Oil Company).

[0155] C2: NK ester DCP (tricyclodecanediethanol dimethacrylate) (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.)

[0156] C3: EBECRYL230 (manufactured by Daicel Allnex) / urethane acrylate.

[0157] C4: EBECRYL9270 (manufactured by Daicel Allnex) / urethane acrylate.

[0158] C5: Karenz MTBD1 (manufactured by Showa Denko Corporation) / a polymeric compound containing thiol groups.

[0159] C6: Karenz MTPE1 (manufactured by Showa Denko Corporation) / a polymeric compound containing thiol groups.

[0160] C7: KAYAMER PM-21 (manufactured by Nippon Kayaku Co., Ltd.) / Polymer compound containing phosphate groups.

[0161] [Preparation of Curable Compositions]

[0162] <Comparative Examples 1-2 and Examples 6-24>

[0163] By mixing the components in the proportions (mass ratios) shown in Table 1 below, the curable compositions (1) to (21) of Comparative Examples 1 to 2 and Examples 6 to 24 were obtained. It should be noted that in Table 1, the numerical values ​​represent the proportions (parts by mass) of each compound relative to 100 parts by mass of the curable composition.

[0164] [Table 1]

[0165]

[0166] In Table 1, "Other" refers to monofunctional free radical polymeric compounds other than specific compounds.

[0167] Using the curable composition obtained above, the viscosity, adhesion, and curing shrinkage rate of the curable composition were determined using the following methods. It should be noted that the curable composition was pressure-filtered using a membrane filter with a 1 μm pore size for the adhesion and curing shrinkage rate evaluations.

[0168] [Determination of viscosity of curable compositions]

[0169] The viscosity of the curable composition was measured using a TVE-25L type E viscometer (manufactured by Toki Sangyo Co., Ltd.) at a sample volume of 1.1 mL, a conical rotor TE-1 (1°34', R24), a rotation speed of 10 rpm, and a temperature of 25 °C.

[0170] [Evaluation of fit]

[0171] <Method for fabricating test units (curable composition using thermal free radical initiators)>

[0172] Test units were fabricated using curable compositions (1), (3) to (9) containing thermal free radical initiators, respectively, by the following method.

[0173] Two glass substrates (length: 15 mm, width: 55 mm, thickness: 1.1 mm) were prepared and cleaned with pure water, acetone, and IPA (isopropanol). After adding 0.5% by mass of 4 μm bead spacers to the obtained curable composition, spin-coating was performed on one of the glass substrates (lower glass substrate 1) to obtain a glass substrate with an uncured curable composition layer (hereinafter also referred to as a glass substrate with an uncured curable composition layer). Then, as... Figure 1A As shown, the other glass substrate (upper glass substrate 2) is pressed together with its center point aligned orthogonally to the glass substrate with the uncured curable composition layer. Clamps are used to press the two substrates together to obtain a press-fit unit. After removing any unwanted curable composition adhering to the press-fit unit, it is placed in a thermal cycling oven and heated at 140°C for 1 hour. After treatment, the substrate is deheated and the clamps are removed to obtain a test unit for evaluating adhesion (containing a cured product obtained from a curable composition using a thermal free radical initiator). By adding bead spacers to the curable composition, a spacer is formed between the lower glass substrate 1 and the upper glass substrate 2 of the obtained test unit, as shown... Figure 1BAs shown, an adhesive layer region 3 is formed by the cured product obtained from the curing composition.

[0174] <Method for fabricating test units (using a curable composition with a photoradical initiator)>

[0175] In Comparative Examples 2 and Examples 13-22 (curable compositions (2), (10)-(19)), ultraviolet light was used to irradiate the coated surface of a glass substrate with an uncured curable composition layer, prepared by the same method as described above, under atmospheric conditions using an ultraviolet light-emitting diode. Specifically, the wavelength of the ultraviolet light source of the ultraviolet light-emitting diode was 365 nm, and the illuminance of the ultraviolet light was 6.6 mW / cm². 2 The irradiation time was 30 seconds (equivalent to a total of 198 mJ / cm). 2 (The amount of irradiation). Then, the other glass substrate (upper glass substrate 2) is pressed together with its center point intersecting the center point of the glass substrate with the curable composition layer irradiated by the above ultraviolet light, and clamps are used to press the two substrates together to obtain a pressing unit. After removing the unwanted curable composition adhering to the pressing unit, it is placed in a thermal cycling oven and heated at 140°C for 1 hour. After the treatment, the substrate is deheated and the clamps are removed to obtain a test unit for evaluating the adhesion (including a cured product obtained from a curable composition using a photoradical initiator).

[0176] It should be noted that in Examples 23 and 24 (curable compositions (20), (21)), a glass substrate with an uncured curable composition layer was prepared using the same method as described above. Another glass substrate (upper glass substrate 2) was then tightly fitted together with the glass substrate having the uncured curable composition layer at its center point, orthogonal to the center point of the substrate. Clips were used to press the two substrates together to obtain a press-fit unit. The wavelength of the ultraviolet light-emitting diode light source was 365 nm, and the ultraviolet illuminance was 6.6 mW / cm². 2 Under the condition of irradiation time of 220 seconds, the above-mentioned crimping unit was irradiated with ultraviolet light (equivalent to a total of 1452 mJ / cm). 2 The amount of irradiation was used to obtain a test unit for evaluating the adhesion (containing a cured product obtained from a curable composition using a photoradical initiator).

[0177] <Methods for evaluating fit>

[0178] Using the universal testing machine EZ-SX100N (Shimadzu Corporation) and Figure 2A and Figure 2B The tightness of the U-shaped clamps shown (upper clamp 4 and lower clamp 5) is evaluated. Specifically, relative to the lower clamp 5 of the testing machine, the fit is evaluated. Figure 3The lower end 7 (the area in contact with the lower clamp 5) of the upper glass substrate 2 of the test unit is positioned to contact the contact portion 6 (the portion in contact with the test unit) of the lower clamp 5. Then, the upper clamp 4 of the testing machine is moved downwards at a speed of 5 mm per second, causing the upper clamp 4 to contact and press against the upper end 8 (the area in contact with the upper clamp 4) of the lower glass substrate 1 of the test unit, thereby vertically peeling the test unit composed of the two substrates from the surface of the adhesive layer (the cured product obtained from the curing composition). The adhesion is calculated by dividing the maximum value of the force applied at this time by the area of ​​the adhesive layer region 3. It should be noted that a higher value indicates better adhesion.

[0179] Evaluation of curing shrinkage rate

[0180] The curing shrinkage rate was calculated using the density method based on the density of the curable composition and its cured product.

[0181] The cured product of the curable composition using a thermal free radical initiator was produced by heat treatment at 140°C for 1 hour in a thermal cycling oven under a nitrogen atmosphere. Furthermore, for the cured product of the curable composition using a photofree radical initiator, ultraviolet light irradiation of 6.6 mW / cm² was achieved using a 365 nm wavelength ultraviolet light-emitting diode as the light source under a nitrogen atmosphere. 2 220 seconds of ultraviolet radiation treatment (equivalent to a total of 1452 mJ / cm²) 2 It is made by (the amount of radiation).

[0182] Density was measured using a dry density meter, AccuPyc II (Shimadzu Corporation).

[0183] The curing shrinkage rate is calculated according to the following formula.

[0184] Curing shrinkage rate (%) = ((d1 / d0) - 1) × 100

[0185] In the above formula, d0 is the density of the curable composition before curing, and d1 is the density of the curable composition after curing.

[0186] It should be noted that the lower the curing shrinkage rate, the smaller the curing shrinkage, and the better the curing shrinkage performance.

[0187] The evaluation results of curable compositions using thermal free radical initiators are shown in Table 2, and the evaluation results of curable compositions using photofree radical initiators are shown in Table 3.

[0188] [Table 2]

[0189]

[0190] [Table 3]

[0191]

[0192] As shown in Tables 2 and 3, the curable compositions containing specific compounds obtained in Examples 6 to 24, compared with the curable compositions of comparative examples that did not use specific compounds, exhibited lower viscosity, higher adhesion when forming cured films, and less curing shrinkage. Specifically, the comparisons under the same conditions were between Comparative Example 1 and Example 7, and between Comparative Example 2 and Example 14.

[0193] Furthermore, in free radical polymerizable compounds, the adhesion is higher when using compounds with thiol groups compared to when not using such compounds. Specifically, the comparison under the same conditions is between Example 14 and Example 15.

[0194] Furthermore, in free radical polymerizable compounds, the binding affinity is higher when using compounds with phosphate groups compared to when not using such compounds. Specifically, in the comparison under the same conditions, Example 17 is compared with Example 18.

[0195] Furthermore, in the free radical polymerizable compound, the curing shrinkage is reduced when aliphatic urethane acrylate is used compared to when the compound is not used. Specifically, in the comparison under the same conditions, Examples 7 and 8 are compared. Moreover, when a polymerizable compound having thiol groups and a polymerizable compound having phosphate groups are used together, the use of aliphatic urethane acrylate in the polymerizable compound results in not only reduced curing shrinkage but also increased adhesion. Specifically, in the comparison under the same conditions, Examples 18 and 19 are compared.

[0196] Industrial availability

[0197] By using a curable composition containing a compound with a specific structure, a free radical curable composition with low viscosity, low curing shrinkage, and high adhesion can be obtained. Therefore, display elements and semiconductor devices obtained by using the curable composition of the present invention as an adhesive exhibit excellent reliability.

[0198] Explanation of reference numerals in the attached figures

[0199] 1: Lower glass substrate; 2: Upper glass substrate; 3: Adhesive layer area; 4: Upper clamp; 5: Lower clamp; 6: Contact area; 7: Lower end; 8: Upper end.

Claims

1. An optical element adhesive comprising a curable composition, said curable composition containing component (A), component (B), and component (C) below. (A) Composition: Monofunctional radical polymeric compounds containing compounds represented by the following formula [1], (B) Component: Free radical initiator (C) Composition: Free radical polymeric compounds with more than two functionalities. X 1 -X 2 -X 3 -X 4 [1] In formula [1], X 1 This represents a structure selected from the following formulas [1-a] to [1-d] and [1-f]. X 2 Represents a straight-chain alkylene group having 2 to 14 carbon atoms, wherein... The alkylene group may optionally undergo at least one of the following substitutions (i) and (ii). (i): The alkylene group with X 1 or X 3 Any non-adjacent -CH2- can be substituted into -O-, -CO-, -COO-, -OCO-, -CONH-, -NHCO-, or -NH-. (ii): Any -CH2- in the alkylene group is substituted with -CH(CH3)-. X 3 This indicates -CO-, -COO-, -OCO-, -CONH-, -NHCO-, or -NH-. X 4 Represents branched alkyl groups with 12 to 40 carbon atoms. T A * indicates a hydrogen atom or a benzene ring, and * indicates a bond. The proportion of component (B) relative to 100 parts by mass of the total free radical polymerizable compound is 0.01 to 10 parts by mass. The proportion of component (A) is 40 to 99 parts by mass relative to the total of 100 parts by mass of component (A) and component (C).

2. The optical element adhesive according to claim 1, wherein, X in the formula [1] 1 X represents a structure selected from equations [1-a] to [1-d]. 2 For the structure shown in the following formula [X1a], X 3 X represents -CO-, -COO-, or -OCO-. 4 Represents branched alkyl groups with 12 to 40 carbon atoms. In formula [X1a], M 1 and M 2 Each can be independently represented as -CH2-CH2-, -CH(CH3)-CH2-, or -CH2-CH(CH3)-, Z 1 Representing -O-, -CO-, -COO-, or -OCO-, where n is an integer from 0 to 4. When n is an integer greater than 2, n Z... 1 and M 2 Each has the above definition independently, and *1 indicates that it is related to X. 1 The bonding position, *2 indicates the position with X. 3 The bonding positions.

3. The optical element adhesive according to claim 1 or 2, wherein, The compound represented by formula [1] is the compound represented by formula [1a] below. In equation [1a], R 1 L represents a hydrogen atom or a methyl group. 1 and L 2 Each can be independently represented as -CH2-CH2-, -CH(CH3)-CH2-, or -CH2-CH(CH3)-, Y 1 Representing -O-, -CO-, -COO-, or -OCO-, where n is an integer from 0 to 4. When n is an integer greater than 2, n Y... 1 and L 2 Each of them independently possesses the above definition, Y 2 Indicates -COO- or -OCO-, L 3 R represents a single bond or a straight-chain or branched alkylene group having 1 to 4 carbon atoms. 2 and R 3 Each independently represents a straight-chain or branched alkyl group having 4 to 18 carbon atoms, R 4 Represents a straight-chain or branched alkyl group having 1 to 18 hydrogen atoms or carbon atoms, wherein, in L 3 When L represents a group other than a single bond, 3 and R 2 ~R 4 The total number of carbon atoms ranges from 11 to 39 in L. 3 In the case of a single bond, R 2 ~R 4 The total number of carbon atoms ranges from 11 to 39.

4. The optical element adhesive according to claim 1, wherein, The radical polymerizable compounds of component (C) include compounds having intramolecular thiol groups.

5. The optical element adhesive according to claim 1 or 2, wherein, The (A) component also includes a monofunctional radical polymeric compound having an intramolecular thiol group.

6. The optical element adhesive according to claim 1, wherein, The free radical polymerizable compound of component (C) includes compounds with intramolecular phosphate groups.

7. The optical element adhesive according to claim 1 or 2, wherein, The (A) component also includes a monofunctional radical polymeric compound having an intramolecular phosphate group.

8. The optical element adhesive according to claim 1 or 2, wherein, The free radical initiator is a thermal free radical initiator that generates free radicals using heat.

9. The optical element adhesive according to claim 1 or 2, wherein, The free radical initiator is a photoradioinitiator that generates free radicals using ultraviolet light.

10. The optical element adhesive according to claim 1, wherein, The adhesive is a solvent-free adhesive.

11. An optical element obtained using the curable composition contained in the optical element adhesive according to any one of claims 1 to 10.

12. An optical element obtained using the optical element adhesive according to any one of claims 1 to 10.

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