Resin composition and cured product thereof

Abstract

The objective of this invention is to provide an adhesive that exhibits sufficient adhesive strength during thermosetting when bonding a substrate to which a lens holder and imaging element are fixed in a camera module assembly, and also exhibits excellent adhesive strength and positional accuracy after curing, following high-temperature and high-humidity durability testing. This invention relates to a resin composition comprising (a) a resin containing (meth)acrylate groups, (b) a specific polyfunctional thiol, and (c) a latent curing agent.

Description

Technical Field

[0001] This invention relates to resin compositions and their cured products. Prior Technology

[0002] A small camera module, mounted on a smartphone or similar device, includes a lens, a cylindrical lens holder for holding the lens, and an imaging element that converts the light collected by the lens into electrical signals and is fixed to a substrate. During the assembly of this small camera module, the lens holder and the substrate to which the imaging element is fixed need to be securely bonded together. These are bonded together using an adhesive (PTL 1).

[0003] When bonding the lens holder and imaging element to the substrate, it is necessary to accurately maintain the distance between the lens and the imaging element. Specifically, the distance between the light-receiving surfaces of the lens and the imaging element needs to be matched with the focal length of the lens. The use of a UV-curable adhesive (PTL 2) for this purpose has been recommended. Citation List Patent documents PTL 1: JP2007-184801A PTL 2: JP2009-141406A Summary of the Invention

[0004] Technical issues Materials such as LCP are widely used in lens holders. Furthermore, it has recently been learned that due to the increased size of imaging elements used to capture sharp images, lens holders have become larger and heavier than conventional lens holders. The inventors have discovered that with the increased weight of the lens holder, problems arise with the use of conventional UV-cured adhesives in terms of initial adhesive strength, adhesive strength after high-temperature and high-humidity durability testing, and positional accuracy.

[0005] The objective of this invention is to provide an adhesive that, when bonding a substrate to which a lens holder and an imaging element are fixed, to a camera module assembly, exhibits sufficient adhesive strength during thermosetting and excellent adhesive strength and positional accuracy after curing, following high-temperature and high-humidity durability tests.

[0006] Solution to the problem The inventors conducted extensive research to solve the above-mentioned problems and discovered that these problems can be solved by using a resin composition comprising (a) a resin containing (meth)acrylate groups, (b) a polyfunctional thiol having a specific structure, and (c) a latent curing agent. This invention was made based on further research following the above findings and includes the following embodiments.

[0007] Item 1. A resin composition comprising: (a) Resins containing (meth)acrylate groups, (b) At least one polyfunctional thiol, selected from the group of compounds represented by formulas (1) and (2): ,and (c) Latent curing agent. Item 2. The resin composition according to Item 1 further comprises: (d) At least one polymerization inhibitor selected from the group consisting of: aluminum N-nitrosophenylhydroxylamine, triphenyl phosphite, p-methoxyphenol and sterically hindered phenol.

[0008] Item 3. The resin composition according to Item 1 or 2 further comprises: (e) an anionic polymerization inhibitor, which is an organic acid.

[0009] Item 4. The resin composition according to any one of items 1 to 3 further comprises: (f) a photopolymerization initiator.

[0010] Item 5. The resin composition according to any one of items 1 to 4 further comprises: (g) epoxidized polybutadiene.

[0011] Item 6. A resin composition according to any one of items 1 to 5, used for assembling a camera module.

[0012] Item 7. A cured product that can be obtained by curing a resin composition according to any one of Items 1 to 6.

[0013] Item 8 Use of a resin composition for assembling a camera module, the resin composition comprising: (a) Resins containing (meth)acrylate groups, (b) At least one polyfunctional thiol, selected from the group of compounds represented by formulas (1) and (2): ,and (c) Latent curing agent.

[0014] Item 9. A method for bonding a camera module lens holder and an imaging element thereon to a camera module substrate, the method comprising bonding the lens holder and the substrate using a resin composition; The resin composition comprises: (a) Resins containing (meth)acrylate groups, (b) At least one polyfunctional thiol, selected from the group of compounds represented by formulas (1) and (2): ,and (c) Latent curing agent.

[0015] [Advantages of this invention] [] When the resin composition of the present invention is used in a camera module assembly to bond the lens holder and imaging element to the substrate thereon, it ensures sufficient adhesive strength during the thermosetting of the adhesive and improves the positional accuracy after high temperature and high humidity durability tests. Simple Explanation of the Diagram

[0016] Figure 1 is a schematic diagram of the adhesion test in the example. Implementation

[0017] In this specification, the weight average molecular weight (Mw) refers to the polystyrene conversion value determined by gel permeation chromatography (GPC) using a solvent such as tetrahydrofuran as the precipitate.

[0018] In this specification, (meth)acrylate, (meth)acrylic acid and (meth)acrylic acid group refer to acrylate or methacrylate, acrylic acid or methacrylic acid and acrylonitrile or methacrylic acid group, respectively.

[0019] (a) Resins containing (meth)acrylate groups Resins containing (meth)acrylate groups include, for example, (meth)acrylates, (meth)acrylate oligomers, acrylic polymers obtained by copolymerizing (meth)acrylate monomers with another monomer, and acrylic polymers that can be obtained by reacting (meth)acrylic acid with a resin.

[0020] Examples of (meth)acrylates include (meth)acrylates. (Meth)acrylates can be monofunctional (meth)acrylates or polyfunctional (meth)acrylates.

[0021] Specific examples of monofunctional (meth)acrylates include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl methacrylate, 2-isocyanoethyl methacrylate, and isoborneol methacrylate (e.g., product name: "IBXA", Osaka Organic Chemical Industry). Hitachi Chemical Co., Ltd., 2-methacryloxyethyltrimethoxysilane, 2-methacryloxyethyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxymethyldiethoxysilane, 4-methacryloxybutyltrimethoxysilane, 4-methacryloxybutyltriethoxysilane, dicyclopentenyloxyethyl methacrylate (e.g., product name: "FA-512M", manufactured by Hitachi Chemical Co., Ltd.), dicyclopentyl methacrylate (e.g., product name: "FA-513M", manufactured by Hitachi Chemical Co., Ltd.), pentamethylhexahydropyridyl methacrylate (e.g., product name: "FA-711MM", manufactured by Hitachi Chemical Co., Ltd.), The following are listed as products manufactured by Hitachi Chemical Co., Ltd.: Tetramethylhexahydropyridyl methacrylate (e.g., product name: "FA-712HM", manufactured by Hitachi Chemical Co., Ltd.), methoxy polyethylene glycol methacrylate (e.g., manufactured by Hitachi Chemical Co., Ltd.), benzyl methacrylate (e.g., product name: "FA-BZM", manufactured by Hitachi Chemical Co., Ltd.), 2-hydroxy-3-acrylic acid methacrylate (e.g., product name: "Light Ester G-201P", manufactured by Kyoeisha Chemical Co., Ltd.), 2-methacrylic acid methacrylate (e.g., product name: "CB-1", manufactured by Shin-Nakamura Chemical Co., Ltd.), methoxy polyethylene glycol methacrylate, phenoxy polyethylene glycol methacrylate (e.g., product name: "PHE-1G", manufactured by Shin-Nakamura Chemical Co., Ltd.), Stearyl methacrylate (e.g., product name: "S", manufactured by Shin-Nakamura Chemical Co., Ltd.), and 2-methacrylic acid ethyl ester (e.g., product name: "SA", manufactured by Shin-Nakamura Chemical Co., Ltd.).Production of 3,4-epoxycyclohexyl methacrylate (e.g., product name: "Cyclomer M100", manufactured by Daicel Corporation) and similar products.

[0022] Specific examples of bifunctional (meth)acrylates include tricyclodecanedimethyl diacrylate (e.g., product name: "SR833", Sartomer), dipropylene glycol diacrylate (e.g., product name: "APG-100", Shin-Nakamura Chemical Co., Ltd.), tricyclodecanedimethyl diacrylate (e.g., product name: "A-DCP", Shin-Nakamura Chemical Co., Ltd.), 1,4-butanediol dimethacrylate (e.g., product name: "FA-124M", manufactured by Hitachi Chemical Co., Ltd.), neopentyl glycol dimethacrylate (e.g., product name: "FA-125M", manufactured by Hitachi Chemical Co., Ltd.), polyethylene glycol #200 dimethacrylate (e.g., product name: "FA-220M", manufactured by Hitachi Chemical Co., Ltd.), and bisphenol A epoxy acrylates (e.g., product name: "Ebecryl") 3700”, Daicel-Allnex Ltd.), EO-modified bisphenol A dimethacrylate (e.g., product name: "FA-321M", manufactured by Hitachi Chemical Co., Ltd.), EO-modified polypropylene glycol #700 dimethacrylate (e.g., product name: "FA-023M", manufactured by Hitachi Chemical Co., Ltd.), ethylene glycol dimethacrylate (e.g., product name: "1G", manufactured by Shin-Nakamura Chemical Co., Ltd.), diethylene glycol dimethacrylate (e.g., product name: "2G", manufactured by Shin-Nakamura Chemical Co., Ltd.), triethylene glycol dimethacrylate (e.g., product name: "3G", manufactured by Shin-Nakamura Chemical Co., Ltd.), polyethylene glycol dimethacrylate (e.g., manufactured by Shin-Nakamura Chemical Co., Ltd.), 2,2-bis[4-(methacryloxyethoxy)phenyl]propane (e.g., product name: "BPE-80N", manufactured by Shin-Nakamura Chemical Co., Ltd.), ethoxylated bisphenol A dimethacrylate (e.g., manufactured by Shin-Nakamura Chemical Co., Ltd.), and tricyclodecanediethanol dimethacrylate (e.g., product name: "DCP", manufactured by Shin-Nakamura Chemical Co., Ltd.).Production of: 1,10-decanediol dimethacrylate (e.g., product name: "DOD-N", produced by Shin-Nakamura Chemical Co., Ltd.), 1,6-hexanediol dimethacrylate (e.g., product name: "HD-N", produced by Shin-Nakamura Chemical Co., Ltd.), 1,9-nonanediol dimethacrylate (e.g., product name: "NOD-N", produced by Shin-Nakamura Chemical Co., Ltd.), neopentyl glycol dimethacrylate (e.g., product name: "NPG", produced by Shin-Nakamura Chemical Co., Ltd.), ethoxylated polypropylene glycol dimethacrylate (e.g., produced by Shin-Nakamura Chemical Co., Ltd.), glycerol dimethacrylate (e.g., product name: "701", produced by Shin-Nakamura Chemical Co., Ltd.), polypropylene glycol dimethacrylate (e.g., produced by Shin-Nakamura Chemical Co., Ltd.), 1,10-decanediol dimethacrylate (e.g., product name: "DOD-N", produced by Shin-Nakamura Chemical Co., Ltd.), 1,6-hexanediol dimethacrylate (e.g., product name: "HD-N", produced by Shin-Nakamura Chemical Co., Ltd.), 1,9-nonanediol dimethacrylate (e.g., product name: "NOD-N", produced by Shin-Nakamura Chemical Co., Ltd.), neopentyl glycol dimethacrylate (e.g., product name: "NPG", produced by Shin-Nakamura Chemical Co., Ltd.), ethoxylated polypropylene glycol dimethacrylate (e.g., produced by Shin-Nakamura Chemical Co., Ltd.), glycerol dimethacrylate (e.g., product name: "701", produced by Shin-Nakamura Chemical Co., Ltd.), polypropylene glycol dimethacrylate (e.g., produced by Shin-Nakamura Chemical Co., Ltd Ltd. (manufacturing) and similar products.

[0023] Specific examples of trifunctional or higher polyfunctional (meth)acrylates include trimethylolpropane trimethacrylate (e.g., product name: "TMPT", manufactured by Shin-Nakamura Chemical Co., Ltd.), tris(2-hydroxyethyl)isocyanurate triacrylate (e.g., product name: "SR368NS", Sartomer), and the like.

[0024] The resin composition of the present invention may contain only one, two or more (meth)acrylates.

[0025] Resins containing (meth)acrylate groups can be acrylate oligomers. The resin composition of the present invention exhibits excellent adhesive strength and moisture resistance after curing, due to its presence of acrylate oligomers.

[0026] Specific examples of resins containing (meth)acrylate groups include urethane acrylate oligomers. Uramate acrylate oligomers are well known to those skilled in the art and can be obtained, for example, by reacting a diisocyanate, preferably an aliphatic diisocyanate, with a hydroxyacrylate. Alternatively, they can be obtained, for example, by reacting a diisocyanate, preferably an aliphatic diisocyanate, with a hydroxyacrylate and a polyol.

[0027] Examples of urethane acrylate oligomers include polycarbonate-based urethane acrylate oligomers. The resin compositions of the present invention exhibit particularly excellent adhesive strength and moisture resistance after curing due to the presence of polycarbonate-based urethane acrylate oligomers. This is believed to be due to the strong interaction between the polycarbonate backbone and the bonded surface (e.g., LCP), and because it is a polymer, it prevents water penetration under high temperature and high humidity conditions. Polycarbonate-based urethane acrylate oligomers are widely known to those skilled in the art and can be obtained, for example, by reacting diisocyanates, preferably aliphatic diisocyanates, with hydroxyacrylates and polycarbonates.

[0028] Specific examples of polycarbonate-based urethane acrylate oligomers include "UN9200A" (Negami Chemical Industrial Co., Ltd.; weight average molecular weight: 15,000), "UV3310B" (Mitsubishi Chemical Corporation; weight average molecular weight: 5,000), and the like.

[0029] Examples of urethane acrylate oligomers include polyether-based urethane acrylate oligomers. Polyether-based urethane acrylate oligomers are well known to those skilled in the art and can be obtained, for example, by reacting diisocyanates, preferably aliphatic diisocyanates, with hydroxyacrylates and polyethers. Specific examples of polyether-based urethane acrylate oligomers include "UV6640B" (Mitsubishi Chemical Corporation; weight average molecular weight: 5,000), "UN6202" (Negami Chemical Industrial Co., Ltd.; weight average molecular weight: 11,000), and the like.

[0030] Resins containing (meth)acrylate groups preferably include (meth)acrylate and / or (meth)acrylate oligomers, acrylic polymers obtained by copolymerizing (meth)acrylate monomers with another non-ester monomer, and acrylic polymers that can be obtained by reacting (meth)acrylic acid with a non-polyester resin. Due to their lack of a polyester structure, these acrylic resins are more stable under high temperature and high humidity conditions after curing.

[0031] The weight average molecular weight of (meth)acrylate oligomers is preferably 4,000 or above.

[0032] In terms of forming sufficiently soft segmental structures in the cured product to enhance durability against thermal and mechanical stress and to optimize storage modulus, the weight-average molecular weight of the (meth)acrylate oligomer is preferably 5,000 or more, more preferably 6,000 or more, more preferably 8,000 or more, and even more preferably 10,000 or more. In terms of the distributability of the binder, the weight-average molecular weight of the (meth)acrylate oligomer is preferably 20,000 or less, more preferably 18,000 or less, and even more preferably 16,000 or less.

[0033] Besides acrylate oligomers, resins containing (meth)acrylate groups can be acrylic polymers obtained by copolymerizing acrylate monomers with another monomer, or they can be obtained by reacting (meth)acrylic acid with a resin.

[0034] Examples of resins containing (meth)acrylate groups include partially (meth)acrylated epoxy resins. Examples of partially (meth)acrylated epoxy resins include those obtainable by reacting (meth)acrylic acid with an epoxy resin. This reaction can be carried out according to conventional methods in the presence of an alkaline catalyst. Each molecule of a partially (meth)acrylated epoxy resin contains an epoxy group and a (meth)acrylate group, and therefore can be cured using various curing systems. The resin compositions of the present invention preferably contain partially (meth)acrylated epoxy resin because they can be effectively cured, have sufficient tack strength after heating, and suppress strength reduction under high temperature and high humidity.

[0035] There are no specific limitations on the epoxy resins that can be used as raw materials in the production of partially (meth)acrylated epoxy resins. Examples include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, 2,2'-diallyl bisphenol A type epoxy resins, hydrogenated bisphenol type epoxy resins, propylene oxide addition bisphenol A type epoxy resins, resorcinol type epoxy resins, biphenyl type epoxy resins, sulfide type epoxy resins, diphenyl ether type epoxy resins, dicyclopentadiene type epoxy resins, naphthyl type epoxy resins, phenolic resins, o-cresol resins, dicyclopentadiene resins, biphenyl resins, naphthol resins, glycidylamine type epoxy resins, alkyl polyol type epoxy resins, rubber-modified epoxy resins, glycidyl ester compounds, bisphenol A type epsulfide resins, and the like.

[0036] Examples of commercially available partially methacrylated epoxy resins include EA-1010LC, EA-1020, EA-5323, EA-5520, EA-CHD, and EMA-1020 (all manufactured by Shin-Nakamura Chemical Co., Ltd.), Ebecryl 860, Ebecryl 3200, Ebecryl 3201, Ebecryl 3412, Ebecryl 3600, Ebecryl 3700, Ebecryl 3701, Ebecryl 3702, Ebecryl 3703, Ebecryl 3800, Ebecryl 6040, and Ebecryl RDX63182 (all manufactured by Daicel Cytec Co., Ltd.), Epoxy Ester M-600A, Epoxy Ester 40EM, Epoxy Ester 70PA, and Epoxy Ester. Epoxy Ester 200PA, Epoxy Ester 80MFA, Epoxy Ester 3002M, Epoxy Ester 3002A, Epoxy Ester 1600A, Epoxy Ester 3000M, Epoxy Ester 3000A, Epoxy Ester 200EA and Epoxy Ester 400EA (all manufactured by Kyoeisha Chemical Co., Ltd.), Denacol Acrylate DA-141, Denacol Acrylate DA-314 and Denacol Acrylate DA-911 (all manufactured by Nagase ChemteX Corporation) and the like.

[0037] Partially (meth)acrylated epoxy resin is preferably a bisphenol A type partially (meth)acrylated epoxy resin.

[0038] There is no specific limitation on the weight average molecular weight (Mw) of the partially (meth)acrylated epoxy resin, but it is preferably 300 to 1000 and more preferably 400 to 800.

[0039] The resin composition of the present invention may contain only one, or two or more resins containing (meth)acrylate groups.

[0040] Based on the entire composition, the resin composition of the present invention preferably contains 30 wt% or more of a resin (a) containing (meth)acrylate groups. Therefore, the resin composition of the present invention exhibits superior heat durability after curing. In this regard, based on the entire composition, the resin composition of the present invention preferably contains 35 wt% or more of acrylate monomers and a resin (a) containing (meth)acrylate groups.

[0041] Based on the entire composition, the resin composition of the present invention preferably contains 80 wt.% or less, and more preferably 60 wt.% or less, of a resin (a) containing (meth)acrylate groups.

[0042] (b) Polyfunctional thiols The resin composition contains at least one multifunctional thiol selected from compounds represented by formulas (1) and (2) below: "Multhiol Y-4" (SC Organic Chemical Co., Ltd.) can be used as a compound represented by formula (1).

[0043] "Multhiol K-3" (SC Organic Chemical Co., Ltd.) can be used as a compound represented by formula (2).

[0044] The resin composition of the present invention exhibits excellent moisture resistance after curing because it contains at least one polyfunctional thiol (b) with a specific structure. One reason for this is that the polyfunctional thiol (b) does not have ester bonds. Many polyfunctional thiols are known to have ester bonds; however, ester bonds are easily hydrolyzed. Therefore, the resin composition of the present invention containing at least one polyfunctional thiol (b) with a specific structure exhibits superior moisture resistance after curing compared to resin compositions containing polyfunctional thiols with ester bonds.

[0045] Furthermore, the resin composition of the present invention exhibits excellent positional accuracy after curing due to its content of at least one polyfunctional thiol (b) with a specific structure. This is believed to be because the polyfunctional thiol (b) does not contain hydroxyl groups and is unlikely to absorb water under high temperature and high humidity after curing. Additionally, the resin composition of the present invention exhibits excellent adhesion at the interface of the bonded surfaces (e.g., LCP) due to its content of at least one polyfunctional thiol (b) with a specific structure. This is believed to be because the polyfunctional thiol (b) does not contain hydroxyl groups and is unlikely to absorb water. Furthermore, the resin composition of the present invention exhibits excellent durability under high temperature and high humidity conditions due to its content of at least one polyfunctional thiol (b) with a specific structure. This is believed to be because the polyfunctional thiol (b) has a flexible backbone and therefore reacts effectively during thermosetting to improve crosslinking density.

[0046] Based on the entire composition, the resin composition of the present invention typically contains at least one polyfunctional thiol (b) in a total amount of 5 to 50 wt%. Based on the entire composition, the resin composition of the present invention preferably contains at least one polyfunctional thiol (b) in a total amount of 10 wt% or more.

[0047] (c) Latent curing agent As a latent curing agent (c), those commonly used in the technical field of UV curing or thermosetting adhesives can be used. Examples of latent curing agents (c) include polyamines, imidazoles, and the like.

[0048] Specific examples of polyamines as latent curing agents (c) include AJICURE (amine adduct type) PN23J, PN31J and PN40J (Ajinomoto Fine-Techno Co., Inc.), Fujiicure FXR-1020, FXR-1030, FXR-1050 and FXR-1080 (manufactured by Fuji Kasei Co., Ltd.), Adeka Hardener EH-4357S and EH-5030S (manufactured by ADEKA), EH-5057 (manufactured by ADEKA), EH-5057PK (manufactured by ADEKA) and the like.

[0049] The resin composition of the present invention may contain only one, two or more latent curing agents (c).

[0050] Regarding excellent adhesion and sufficient addition reaction with acrylic monomers and oligomers, the resin composition of the present invention preferably contains 5 wt% or more, more preferably 10 wt% or more of a latent curing agent (c) in the whole composition. Regarding excellent moisture resistance and dispensability, the resin composition of the present invention preferably contains 40 wt% or less, more preferably 30 wt% or less of a latent curing agent (c) in the whole composition.

[0051] (d) Polymerization inhibitors The resin composition of the present invention contains at least one polymerization inhibitor selected from the group consisting of: N-nitrosophenylhydroxylamine aluminum, triphenyl phosphite, p-methoxyphenol and hindered phenol, for the purpose of inhibiting free radical polymerization.

[0052] In terms of inhibiting free radical polymerization, the resin composition of the present invention is preferably based on containing 0.01 to 5 wt% of a polymerization inhibitor (d) in the whole composition.

[0053] (e) Inhibitors of anionic polymerization of organic acids [] The resin composition of the present invention contains an organic acid anionic polymerization inhibitor (e) for the purpose of inhibiting anionic polymerization. Specific examples of organic acid anionic polymerization inhibitor (e) include barbituric acid.

[0054] In terms of inhibiting anionic polymerization, the resin composition of the present invention is preferably based on containing 0.1 to 5 wt% of a polymerization inhibitor (e) in the whole composition.

[0055] (f) Photopolymerization initiators There are no specific limitations on the photopolymerization initiator (f), and those commonly used in the field of UV curing technology can be used.

[0056] Specific examples of photopolymerization initiators include Omnirad 651 (2,2-dimethoxy-1,2-diphenylethyl-1-one), Omnirad 184 (1-hydroxy-cyclohexyl-phenyl-one), Omnirad 1173 (2-hydroxy-2-methyl-1-phenyl-prop-1-one), Omnirad 2959 (1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-prop-1-one), Omnirad 127 (2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionic)-benzyl]phenyl}-2-methyl-prop-1-one), Omnirad 907 (2-methyl-1-(4-methylthiophenyl)-2-morpholinylprop-1-one), and Omnirad 369. (2-Benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butanone-1), Omnirad 379 (2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone), Omnirad TPO (2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide), Omnirad 819 (bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide), Omnirad 784 (bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrolo-1-yl)-phenyl)titanium), Omnirad OXE 01 (1-[4-(phenylthio)phenyl]-1,2-octanedione, 2-(o-benzoyl oxime)), Omnirad OXE 02 (1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-ethyl ketone, 1-(O-acetyl oxime)), Omnirad 754 (a blend of 2-[2-side-oxy-2-phenylacetoxyethoxy]ethyl ester and 2-(2-hydroxyethoxy)ethyl ester of oxy-phenyl-acetic acid), Omnirad TPO, LR8893 and LR8970 (all produced by IGM Resins BV), DETX-S (2,4-diethylthioxanthone) (produced by Nippon Kayaku Co., Ltd.), Ubecryl P36 (produced by UCB) and the like.

[0057] Photopolymerization initiators can be used alone or in combination of two or more.

[0058] Regarding excellent UV curability, the resin composition of the present invention preferably contains 0.1 wt% or more, and more preferably 0.5 wt% or more, of a photopolymerization initiator (f) throughout the composition. Regarding the stability of adhesion, the resin composition of the present invention preferably contains 5 wt% or less, and more preferably 2 wt% or less, of a photopolymerization initiator (f) throughout the composition.

[0059] (g) Epoxidized polybutadiene The resin composition of the present invention may further contain epoxidized polybutadiene (g).

[0060] Epoxidized polybutadiene (g) is preferably epoxidized 1,2-polybutadiene.

[0061] In terms of achieving excellent compatibility, the resin composition of the present invention is preferably based on containing 5 to 20 wt% (g) of epoxidized polybutadiene throughout the composition.

[0062] (h) Other components The resin composition of the present invention may further contain other components. Examples of other components typically include rheology modifiers, tackifiers, fillers, and the like.

[0063] Physical properties The resin composition of the present invention preferably has an adhesive strength of 7 MPa or higher after heat and UV curing. Furthermore, the resin composition of the present invention preferably has an adhesive strength reduction rate of 40% or less after reliability testing (85°C / 85% RH, 250 hours).

[0064] use The resin composition of the present invention is preferably used for assembling camera modules and / or sensing modules. Sensing modules are optical sensors used to read laser light, and include, for example, LiDAR (Light Detection and Ranging) and the like. More specifically, the resin composition of the present invention is preferably used in camera module assemblies to bond lens holders and imaging elements to a substrate thereon. In the foregoing, the term "camera module" is not specifically limited, and examples include small camera modules for smartphones and the like. The resin composition of the present invention is also preferably used in sensing module assemblies to bond constituent members of this module, such as at least two members selected from the group consisting of: liquid crystal polymers, polycarbonate, polyamide, polybutylene terephthalate, cyclic olefin polymers, ceramics, SUS, aluminum, and nickel.

[0065] Example [] The invention is described below with reference to examples; however, the invention is not limited to these examples and such. Unless otherwise specified, the values ​​for each component in the table indicate weight (g).

[0066] The binder compositions of Examples 1 to 12 and Comparative Examples 1 to 4 were each prepared by mixing the components in the proportions shown in Table 2. Specifically, the components were thoroughly dispersed using a three-roll mill, and the resulting mixture, along with other additives, was mixed using a planetary mixer, followed by vacuum defoaming to obtain the binder composition.

[0067] The polyfunctional thiols “Multhiol Y-4” (SC Organic Chemical Co., Ltd.), “Multhiol K-3” (SC Organic Chemical Co., Ltd.), “Multhiol Y-3” (SC Organic Chemical Co., Ltd.) and “C3TS-G” (Shikoku Chemicals Corporation) are compounds represented by the following formulas (1) to (4), respectively. Table 1 [] Multhiol Y-4 Multhiol K-3 Multhiol Y-3 C3TS-G

[0068] The physical properties of each are evaluated below. Table 2 shows the evaluation results.

[0069] Adhesion strength test The adhesive strength test was performed as shown in Figure 1. Details are described below. The adhesive composition was dispensed in 5 mm × 5 mm squares onto a 15 mm × 15 mm ceramic substrate, resulting in a weight of approximately 3.5 mg. A PC wafer with a 7 mm × 7 mm shape was then mounted, and the adhesive thickness was adjusted to 100 μm. Temporary curing was performed by irradiating the sample with a 365 nm LED from four circumferential directions at 500 mW / cm² for 4 seconds. The sample was then thermocured in a hot air circulating oven at 80°C for 60 minutes and measured using a Dage 4000 universal adhesive tester at a shear rate of 200 μm / s and a shear height of 120 μm.

[0070] The reliability test conditions are 85℃ / 85% RH and 250 hours.

[0071] Table 2 shows the evaluation results. The resin compositions of Examples 1 to 12 exhibited excellent adhesive strength in the initial stage of thermosetting and showed a low rate of decrease in adhesive strength after reliability testing. This is because they contain thiol compounds with specific structures and the ratio of component (a) to the whole composition is 30 wt% or more.

[0072] On the other hand, the resin compositions of Comparative Examples 1 and 2 showed a high rate of decrease in adhesive strength after reliability testing, which is because they contain thiols that have a different structure from the thiols of the present invention.

[0073] Furthermore, the resin composition of Comparative Example 3 exhibited poor positional accuracy after curing and high-temperature and high-humidity durability testing. This was because it contained thiol compounds with hydroxyl groups, which tended to absorb water during the high-temperature and high-humidity durability testing of the resin composition.

[0074] Furthermore, the resin composition of Comparative Example 4 exhibits poor durability under high temperature and high humidity conditions. This is because it contains thiol compounds with poor mobility, which tend to lead to insufficient cross-linking and thus allow water to penetrate into the resin composition and the interface between the resin composition and the coated surface. Table 2 type Compound Name "Product Name" (Manufacturer) Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 Comparison Examples 1 Comparison Examples 2 Comparison Examples 3 Comparison Examples 4 (a) Acrylic monomers and resins containing (meth)acrylate groups Tricyclodecanediethanol diacrylate "SR833" (Sartomer) 46 43 64 39 35 20 20 15 45 37 42 47 Isoborneol acrylate "IBXA" (Osaka Organic Chemical Industry Ltd.) 15 15 15 15 15 15 Polycarbonate-based amino acrylate oligomer "UV3310B" (Mitsubishi Chemical Corporation) 20 20 20 20 20 20 Bisphenol A type partially (meth)acrylated epoxy resin "EA-1010LC" (Shin-Nakamura Chemical Co., Ltd.) 61 10 10 20 20 10 (b) Polyfunctional thiols "Multhiol Y-4" (SC Organic Chemical Co., Ltd.) 34 31 15 15 "Multhiol K-3" (SC Organic Chemical Co., Ltd.) 37 16 19 35 15 15 15 15 (b') Polyfunctional thiols Neopentyl tetra(3-mercaptopropionate) "PEMP" (SC Organic Chemical Co., Ltd.) 35 1,3,5-Tris-(2-(3-thiobutyryloxy)ethyl)-1,3,5-triazinane-2,4,6-trione "NR" (Karenz) 43 "Multhiol Y-3" (SC Organic Chemical Co., Ltd.) 38 "C3TS-G" (Shikoku Chemicals Corporation) 33 (c) Latent curing agent "AJICURE 23J" (Ajinomoto Fine-Techno Co., Inc.) 15 15 15 15 15 15 15 15 15 15 "5057P" (Adeka) 25 25 25 25 25 25 (d) Polymerization inhibitors Triphenyl phosphite 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Neopentyl tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) "Irganox 1010" (BASF) 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 (e) Anionic polymerization inhibitors barbituric acid 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 (f) Photopolymerization initiators 1-Hydroxycyclohexylphenyl ketone "Omnirad 184" (IGM Resins BV) 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 (g) Epoxidized polybutadiene Epoxidized 1,2-polybutadiene "BF-1000" (Adeka) 10 10 Silane coupling agent 3-Glycidyloxypropyltrimethoxysilane "KBM-403" (Shin-Etsu Chemical Co., Ltd.) 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 rheology modifiers NK200 (Nippon Aerosil Co., Ltd.) 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 total 107.5 107.5 107.5 107.5 107.5 107.5 107.5 107.5 107.5 107.5 107.5 107.5 107.5 107.5 107.5 107.5 Adhesion strength to LCP after curing (MPa) 10 14 11 9 11 14 8 10 13 9 10 13 11 14 8 14 Reduction in adhesive strength after reliability testing (%) 25 20 27 twenty three 20 15 5 7 10 10 10 7 70 60 35 30

Claims

1. A camera module assembly comprising: a substrate on which an imaging element is fixed; a lens holder; and a resin composition configured to bond the substrate and the lens holder, the resin composition comprising: (a) a resin containing (meth)acrylate groups, (b) a polyfunctional thiol having the following formula (2): , and (c) a latent curing agent.

2. The camera module assembly of claim 1, wherein the resin composition further comprises: (d) at least one polymerization inhibitor selected from the group consisting of: aluminum N-nitrosophenylhydroxylamine, triphenyl phosphite, p-methoxyphenol and sterically hindered phenol.

3. The camera module assembly of claim 1 or 2, wherein the resin composition further comprises: (e) an anionic polymerization inhibitor, which is an organic acid.

4. The camera module assembly of claim 1 or 2, wherein the resin composition further comprises: (f) a photopolymerization initiator.

5. The camera module assembly of claim 1 or 2, wherein the resin composition further comprises: (g) epoxidized polybutadiene.

6. A camera module comprising a cured product obtainable by curing a resin composition of a camera module assembly as claimed in any one of claims 1 to 5, wherein the cured product bonds the substrate and the lens holder.

7. A camera module comprising: a substrate on which an imaging element is fixed; a lens holder; and a cured product bonding the substrate and the lens holder, wherein the cured product is formed by a curing resin composition comprising: (a) a resin containing (meth)acrylate groups, (b) a polyfunctional thiol having the following formula (2): , and (c) a latent curing agent.

8. A method for bonding a camera module lens holder and an imaging element thereon to a camera module substrate, the method comprising: assembling the lens holder and the substrate using a resin composition; the resin composition comprising: (a) a resin containing (meth)acrylate groups, (b) a polyfunctional thiol having the following formula (2): , and (c) a latent curing agent; and curing the resin composition to bond the lens holder and the substrate.

9. Use of a resin composition for assembling a camera module, the resin composition comprising: (a) a resin containing (meth)acrylate groups, (b) at least one polyfunctional thiol selected from the group consisting of compounds represented by formulas (1) and (2) below, and (c) a latent curing agent.

10. A method for bonding a camera module lens holder and an imaging element thereon to a camera module substrate, the method comprising bonding the lens holder and the substrate using a resin composition; the resin composition comprising: (a) a resin containing (meth)acrylate groups, (b) at least one polyfunctional thiol selected from the group consisting of compounds represented by formulas (1) and (2) below, and (c) a latent curing agent.

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