Resin composition and cured product thereof

Abstract

An object of the present invention is to provide an adhesive that has sufficient adhesive strength during thermal curing when a lens holder and a substrate on which an imaging element is fixed are bonded in a camera module assembly, and also has excellent adhesive strength and position accuracy after a high-temperature and high-humidity durability test after curing. The present invention relates to a resin composition comprising (a) a (meth)acrylate group-containing resin, (b) a specific polyfunctional mercaptan, and (c) a latent curing agent.

Description

Technical Field

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

[0002] A small camera module installed in a smartphone or similar device has a lens, a cylindrical lens holder that holds the lens, and an imaging element fixed to a substrate that converts the light collected by the lens into an electrical signal. 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. An adhesive is used to bond them together (PTL 1).

[0003] When bonding a lens mount to a substrate on which the imaging element is attached, it is necessary to precisely 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 match the focal length of the lens. For this purpose, a UV-curable adhesive (PTL 2) has been proposed.

[0004] Reference List

[0005] Patent documents

[0006] PTL 1: JP2007—184801A

[0007] PTL 2: JP2009—141406A Summary of the Invention

[0008] Technical issues

[0009] Materials such as LCP are widely used as lens mount materials. Furthermore, it has recently been understood that lens mounts are becoming increasingly larger and heavier compared to conventional ones due to the larger imaging elements used to capture sharp images. The inventors have discovered that with the increased weight of the lens mount, the use of conventional UV-cured adhesives causes problems with initial bond strength, as well as bond strength and positional accuracy after high-temperature and high-humidity durability testing.

[0010] One object of the present invention is to provide an adhesive that has sufficient adhesive strength during the thermosetting process of bonding a lens holder and a substrate on which an imaging element is fixed in a camera module assembly, and also exhibits excellent adhesive strength and positional accuracy after high temperature and high humidity durability tests following curing.

[0011] Solution to the problem

[0012] The inventors conducted extensive research to address the aforementioned problems and discovered that these problems could 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 completed based on further research following the above findings and includes the following aspects.

[0013] Project 1. A resin composition comprising:

[0014] (a) Resins containing (meth)acrylate groups,

[0015] (b) At least one polyfunctional thiol selected from compounds represented by formulas (1) and (2):

[0016]

[0017] (c) Latent curing agent.

[0018] Project 2. The resin composition according to Project 1, further comprising:

[0019] (d) At least one polymerization inhibitor, said polymerization inhibitor being selected from N-nitrosophenylhydroxylamine aluminum, triphenyl phosphite, p-methoxyphenol and hindered phenol.

[0020] Project 3. The resin composition according to Project 1 or 2, further comprising: (e) an anionic polymerization inhibitor, said anionic polymerization inhibitor being an organic acid.

[0021] Item 4. The resin composition according to any one of Items 1 to 3, further comprising: (f) a photopolymerization initiator.

[0022] Item 5. The resin composition according to any one of Items 1 to 4, further comprising: (g) epoxidized polybutadiene.

[0023] Item 6. The resin composition according to any one of Items 1 to 5, used for assembling a camera module.

[0024] Item 7. A cured product obtainable by curing a resin composition according to any one of Items 1 to 6.

[0025] Project 8: Use of the resin composition for assembling a camera module, said resin composition comprising:

[0026] (a) Resins containing (meth)acrylate groups,

[0027] (b) At least one polyfunctional thiol selected from compounds represented by formulas (1) and (2):

[0028]

[0029] (c) Latent curing agent.

[0030] Item 9. A method for bonding a camera module lens mount and a camera module substrate on which an imaging element is fixed, the method comprising bonding the lens mount and the substrate using a resin composition;

[0031] The resin composition comprises:

[0032] (a) Resins containing (meth)acrylate groups,

[0033] (b) At least one polyfunctional thiol selected from compounds represented by formulas (1) and (2):

[0034]

[0035] (c) Latent curing agent.

[0036] Beneficial effects of the invention

[0037] When the resin composition of the present invention is used in a camera module assembly to bond a lens holder and a substrate on which an imaging element is fixed, sufficient bond strength is ensured during the thermosetting of the adhesive, and the positional accuracy can be improved after high temperature and high humidity durability tests following curing. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the adhesion test in the embodiment. Detailed Implementation

[0039] In this specification, the weight-average molecular weight (Mw) refers to the converted value of polystyrene determined by gel permeation chromatography (GPC) using a solvent such as tetrahydrofuran as the eluent.

[0040] In this specification, (meth)acrylate, (meth)acrylic acid, and (meth)acryloyl group refer to acrylate or methacrylate, acrylic acid or methacrylic acid, and acryloyl or methacryloyl group, respectively.

[0041] (a) Resins containing (meth)acrylate groups

[0042] 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 those obtained by reacting (meth)acrylic acid with a resin.

[0043] Examples of (meth)acrylates include esters of (meth)acrylate. Esters of (meth)acrylate can be monofunctional or polyfunctional.

[0044] Specific examples of monofunctional (meth)acrylic acid esters include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl methacrylate, 2-isocyanoethyl methacrylate, isobornyl methacrylate (e.g., product name: "IBXA", Osaka Organic Chemical Industry Ltd.), 2-methacryloyloxyethyltrimethoxysilane, 2-methacryloyloxyethyltriethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, 3-methacryloyloxypropyltriethoxysilane, 3-methacryloyloxymethyldiethoxysilane, 4-methacryloyloxybutyltrimethoxysilane, 4-methacryloyloxybutyltriethoxysilane, ethylene glycol dicyclopentenyl ether methacrylate (e.g., product name: "FA-512M", manufactured by Hitachi Chemical). The following chemicals are manufactured by Hitachi Chemical Co., Ltd.: dicyclopentyl methacrylate (e.g., product name: "FA-513M", manufactured by Hitachi Chemical Co., Ltd.), pentamethylpiperidinium methacrylate (e.g., product name: "FA-711MM", manufactured by Hitachi Chemical Co., Ltd.), tetramethylpiperidinium 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-acryloyloxypropyl methacrylate (e.g., product name: "Light Ester G-201P", manufactured by Kyoeisha Chemical Co., Ltd.), and 2-methacryloyloxyethyl phthalic acid (e.g., product name: "CB-1", manufactured by Shin-Nakamura Chemical Co., Ltd.). (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.), octadecyl methacrylate (e.g., product name: "S", manufactured by Shin-Nakamura Chemical Co., Ltd.), and 2-methacryloyloxyethyl succinate (e.g., product name: "SA", manufactured by Shin-Nakamura Chemical Co., Ltd.).Production of 3,4-epoxycyclohexyl methyl methacrylate (e.g., product name: "Cyclomer M100", manufactured by Daicel Corporation), etc.

[0045] Specific examples of bifunctional (meth)acrylate esters include tricyclodecanediethanol diacrylate (e.g., product name: "SR833", Sartomer), dipropylene glycol diacrylate (e.g., product name: "APG-100", Shin-Nakamura Chemical Co., Ltd.), tricyclodecanediethanol 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 acrylate (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.), etc. 2,2-bis[4-(methacryloyloxyethoxy)phenyl]propane (e.g., product name: "BPE-80N", produced by Shin-Nakamura Chemical Co., Ltd.), ethoxylated bisphenol A dimethacrylate (e.g., produced by Shin-Nakamura Chemical Co., Ltd.), tricyclodecanediethanol dimethacrylate (e.g., product name: "DCP", produced 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.), glyceryl 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.). (Co., Ltd. production, etc.)

[0046] Specific examples of trifunctional or higher polyfunctional (meth)acrylic acid esters include trimethylolpropane trimethacrylate (e.g., product name: "TMPT", manufactured by Shin-Nakamura Chemical Co., Ltd.), tri(2-hydroxyethyl)isocyanurate triacrylate (e.g., product name: "SR368NS", Sartomer), etc.

[0047] The resin composition of the present invention may contain only one, two or more of the (meth)acrylates.

[0048] Resins containing (meth)acrylate groups may be acrylate oligomers. The resin compositions of the present invention exhibit excellent adhesive strength and moisture resistance after curing because they contain acrylate oligomers.

[0049] Specific examples of resins containing (meth)acrylate groups include polyurethane acrylate oligomers. Polyurethane 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 hydroxyl acrylate. Alternatively, they can be obtained, for example, by reacting a diisocyanate (preferably an aliphatic diisocyanate) with a hydroxyl acrylate and a polyol.

[0050] Examples of polyurethane acrylate oligomers include polycarbonate-based polyurethane acrylate oligomers. The resin compositions of the present invention exhibit particularly excellent adhesive strength and moisture resistance after curing because they contain polycarbonate-based polyurethane acrylate oligomers. This is believed to be due to the strong interaction between the polycarbonate backbone and the surface to be bonded (such as LCP), and because it is a polymer, it can prevent water penetration at high temperatures and high humidity. Polycarbonate-based polyurethane 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 an acrylate hydroxyl ester and polycarbonate.

[0051] Specific examples of polycarbonate-based polyurethane acrylate oligomers include “UN9200A” (Negami Chemical Industrial Co., Ltd.; weight average molecular weight: 15,000) and “UV3310B” (Mitsubishi Chemical Corporation; weight average molecular weight: 5,000).

[0052] Examples of polyurethane acrylate oligomers include polyether-based polyurethane acrylate oligomers. Polyether-based polyurethane 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 an acrylate hydroxyl ester and a polyether. Specific examples of polyether-based polyurethane acrylate oligomers include “UV6640B” (Mitsubishi Chemical Corporation; weight average molecular weight: 5,000) and “UN6202” (Negami Chemical Industrial Co., Ltd.; weight average molecular weight: 11,000), etc.

[0053] 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 resins obtained by reacting (meth)acrylic acid with a non-polyester resin. Due to their lack of polyester structure, these acrylate resins are more stable under high temperature and high humidity conditions after curing.

[0054] The weight-average molecular weight of the (meth)acrylate oligomer is preferably 4,000 or greater.

[0055] In terms of forming sufficiently soft segmental structures in the cured product to enhance durability against thermal and mechanical stress and optimize storage modulus, the weight-average molecular weight of the (meth)acrylate oligomers is preferably 5,000 or greater, more preferably 6,000 or greater, even more preferably 8,000 or greater, and even more preferably 10,000 or greater. In terms of distributability to the adhesive, the weight-average molecular weight of the (meth)acrylate oligomers is preferably 20,000 or less, more preferably 18,000 or less, and even more preferably 16,000 or less.

[0056] In addition to acrylate oligomers, resins containing (meth)acrylate groups can also be acrylic polymers obtained by copolymerizing an acrylate monomer with another monomer, or they can be obtained by reacting (meth)acrylic acid with a resin.

[0057] Examples of resins containing (meth)acrylate groups include partially (meth)acrylated epoxy resins. Examples of partially (meth)acrylated epoxy resins include those obtained by reacting (meth)acrylic acid with an epoxy resin. Such a reaction can be carried out according to conventional methods in the presence of a basic catalyst. Each molecule of partially (meth)acrylated epoxy resin contains an epoxy group and a (meth)acrylate group, and therefore can be cured using a variety of curing systems. The resin compositions of the present invention preferably contain partially (meth)acrylated epoxy resins because they cure efficiently, have sufficient adhesive strength after heating, and suppress strength reduction after high temperature and high humidity.

[0058] 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, naphthalene type epoxy resins, phenolic resins, o-cresol resins, dicyclopentadiene resins, biphenyl resins, naphthalene resins, glycidylamine resins, alkyl polyol type epoxy resins, rubber-modified epoxy resins, glycidyl ester compounds, and bisphenol A type epsulfide resins, etc.

[0059] 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 EbecrylRDX63182 (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 Kyoisha Chemical Co., Ltd.), Denacol Acrylate DA-141, Denacol Acrylate Da-314 and Denacol Acrylate DA-911 (all manufactured by Nagase ChemteX Corporation), etc.

[0060] The partially (meth)acrylated epoxy resin is preferably a bisphenol A type partially (meth)acrylated epoxy resin.

[0061] The weight-average molecular weight (Mw) of the partially (meth)acrylated epoxy resin is not specifically limited, but is preferably 300 to 1000, and more preferably 400 to 800.

[0062] The resin composition of the present invention may contain only one, or two or more, resins containing (meth)acrylate groups.

[0063] Based on the entire composition, the resin composition of the present invention preferably comprises a resin (a) containing (meth)acrylate groups in a total amount of 30% by weight or more. 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 more preferably comprises a resin (a) containing acrylate monomers in a total amount of 35% by weight or more and (meth)acrylate groups.

[0064] Based on the entire composition, the resin composition of the present invention preferably comprises 80% by weight or less, and more preferably 60% by weight or less, of a resin (a) containing (meth)acrylate groups.

[0065] (b) Polyfunctional thiols

[0066] The resin composition comprises at least one polyfunctional thiol, said polyfunctional thiol being selected from compounds represented by the following formulas (1) and (2):

[0067]

[0068] “Multhiol Y-4” (SC Organic Chemical Co., Ltd.) can be used as a compound represented by formula (1).

[0069] “Multhiol K-3” (SC Organic Chemical Co., Ltd.) can be used as the compound represented by formula (2).

[0070] The resin composition of the present invention exhibits excellent moisture resistance after curing because it contains at least one polyfunctional thiol (b) having 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 readily hydrolyzed. Therefore, compared to resin compositions containing polyfunctional thiols having ester bonds, the resin composition of the present invention, which contains at least one polyfunctional thiol (b) having a specific structure as a polyfunctional thiol, exhibits superior moisture resistance after curing.

[0071] Furthermore, the resin composition of the present invention exhibits excellent positional accuracy after curing because it contains 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 does not readily absorb water under high temperature and high humidity after curing. Additionally, the resin composition of the present invention exhibits excellent adhesion at the interface with the surface to be bonded (e.g., LCP) because it contains 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 does not readily absorb water. Furthermore, the resin composition of the present invention exhibits excellent durability after high temperature and high humidity because it contains 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.

[0072] 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% by weight. 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% by weight or more.

[0073] (c) Latent curing agent

[0074] 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, etc.

[0075] Specific examples of polyamines as latent curing agents (c) include AJICURE (amine adduct type) PN23J, PN31J and PN40J (Ajinomoto Fine-Techno Co., Inc.), Fujicure 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), etc.

[0076] The resin composition of the present invention may contain only one, two or more of the latent curing agents (c).

[0077] Regarding excellent adhesion and sufficient addition reaction with acrylic monomers and oligomers, the resin composition of the present invention preferably contains 5% by weight or more, more preferably 10% by weight or more of a latent curing agent (c), based on the entire composition. Regarding excellent moisture resistance and dispensability, the resin composition of the present invention preferably contains 40% by weight or less, more preferably 30% by weight or less of a latent curing agent (c), based on the entire composition.

[0078] (d) Polymerization inhibitors

[0079] For the purpose of inhibiting free radical polymerization, the resin composition of the present invention contains at least one polymerization inhibitor (d), said polymerization inhibitor being selected from N-nitrosophenylhydroxylamine aluminum, triphenyl phosphite, p-methoxyphenol and hindered phenol.

[0080] Regarding the inhibition of free radical polymerization, the resin composition of the present invention preferably contains 0.01 to 5% by weight of a polymerization inhibitor (d) based on the entire composition.

[0081] (e) Anionic polymerization inhibitors (i.e., organic acids)

[0082] For the purpose of inhibiting anionic polymerization, the resin composition of the present invention comprises an anionic polymerization inhibitor (e), which is an organic acid. Specific examples of anionic polymerization inhibitors (e) that are organic acids include barbituric acid.

[0083] Regarding the inhibition of anionic polymerization, the resin composition of the present invention preferably contains 0.1 to 5% by weight of a polymerization inhibitor (e) based on the entire composition.

[0084] (f) Photopolymerization initiator

[0085] The photopolymerization initiator (f) is not specifically limited and can be those commonly used in the field of UV curing technology.

[0086] Specific examples of photopolymerization initiators include Omnirad 651 (2,2-dimethoxy-1,2-diphenylethyl-1-one), Omnirad 184 (1-hydroxy-cyclohexyl-phenyl-methyl ketone), Omnirad 1173 (2-hydroxy-2-methyl-1-phenyl-propan-1-one), Omnirad 2959 (1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one), Omnirad 127 (2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propanoyl)-benzyl]phenyl}-2-methyl-propan-1-one), Omnirad 907 (2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one), Omnirad... 369 (2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1), Omnirad 379 (2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholino)phenyl]-1-butanone), Omnirad TPO (2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide), Omnirad 819 (bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide), Omnirad 784 (bis(n5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrolo-1-yl)-phenyl)titanium), Omnirad OXE 01 (1,2-octanedione, 1-[4-(phenylthio)phenyl]-, 2-(o-benzoyl oxime)), Omnirad OXE 02 (acetone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-,1-(O-acetyloxime)), Omnirad 754 (a blend of 2-[2-oxo-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), etc.

[0087] Photopolymerization initiators can be used alone or in combination of two or more.

[0088] Regarding excellent UV curability, the resin composition of the present invention preferably contains 0.1% by weight or more, and more preferably 0.5% by weight or more of a photopolymerization initiator (f), based on the entire composition. Regarding the stability of adhesion, the resin composition of the present invention preferably contains 5% by weight or less, and more preferably 2% by weight or less of a photopolymerization initiator (f), based on the entire composition.

[0089] (g) Epoxidized polybutadiene

[0090] The resin composition of the present invention may further comprise epoxidized polybutadiene (g).

[0091] Epoxidized polybutadiene (g) is preferably epoxidized 1,2-polybutadiene.

[0092] In order to achieve excellent compatibility, the resin composition of the present invention preferably contains 5 to 20% by weight of epoxidized polybutadiene (g) based on the whole composition.

[0093] (h) Other components

[0094] The resin composition of the present invention may also contain other components. Examples of other components include conventional rheology modifiers, viscosity enhancers, fillers, etc.

[0095] Physical properties

[0096] The resin composition of the present invention preferably has an adhesive strength of 7 MPa or greater after heat and UV curing. Furthermore, after reliability testing (85°C / 85% RH, 250 hours), the resin composition of the present invention preferably has an adhesive strength reduction rate of 40% or less.

[0097] use

[0098] The resin composition of the present invention is preferably used for assembling camera modules and / or sensing modules. The sensing module is an optical sensor for reading laser light, and includes, for example, LiDAR (light detection and ranging). More specifically, the resin composition of the present invention is preferably used in a camera module assembly to bond a lens holder and a substrate on which an imaging element is fixed. In the foregoing, the camera module is not specifically limited, and examples include small camera modules for smartphones, etc. The resin composition of the present invention is also preferably used in a sensing module assembly to bond constituent parts of the module, such as at least two parts selected from liquid crystal polymers, polycarbonate, polyamide, polybutylene terephthalate, cyclic olefin polymers, ceramics, SUS, aluminum, and nickel.

[0099] Example

[0100] The present invention is described below with reference to embodiments; however, the present invention is not limited to these embodiments, etc. The values ​​of each component in the table represent weight (g) unless otherwise stated.

[0101] The adhesive 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 adhesive composition.

[0102] “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) used as polyfunctional thiols are compounds represented by formulas (1) to (4) below, respectively.

[0103] Table 1

[0104]

[0105] The physical properties are evaluated as follows. Table 2 shows the evaluation results.

[0106] Adhesion strength test

[0107] Adhesion strength test such as Figure 1 The procedure was performed as shown. Details are as follows. The adhesive composition was dispensed into a 5mm × 5mm square onto a 15mm × 15mm ceramic substrate, resulting in a weight of approximately 3.5mg. Then, a 7mm × 7mm PC chip was mounted, and the adhesive thickness was adjusted to 100μm. A 365nm LED was used from four surrounding directions at 500mW / cm². 2 Irradiation for 4 seconds was used for temporary curing. The sample was then heat-cured in a hot air circulating oven at 80°C for 60 minutes and measured using a Dage4000 universal adhesive bonding tester at a shear rate of 200 μm / s and a shear height of 120 μm.

[0108] The reliability test conditions were 85℃ / 85%RH and 250 hours.

[0109] Table 2 shows the evaluation results. It has been shown that the resin compositions of Examples 1 to 12 have excellent adhesive strength in the initial stage of thermosetting and exhibit a low rate of adhesive strength reduction after reliability testing, because they contain thiol compounds with specific structures and the ratio of component (a) to the whole composition is 30% by weight or more.

[0110] On the other hand, it has been shown that the resin compositions of Comparative Examples 1 and 2 exhibited a higher rate of decrease in adhesive strength after reliability testing because they contain thiols that have a different structure from the thiols of the present invention.

[0111] Furthermore, it has been shown that the resin composition of Comparative Example 3 has poor positional accuracy after high temperature and high humidity durability testing following curing, because it contains thiol compounds with hydroxyl groups, which makes the resin composition prone to absorbing water during high temperature and high humidity durability testing.

[0112] Furthermore, it has been shown that the resin composition of Comparative Example 4 has poor durability after high temperature and high humidity because it contains thiol compounds with poor flowability, which tend to lead to insufficient crosslinking, thereby allowing water to penetrate into the resin composition and the interface between the resin composition and the coated surface.

[0113]

[0114]

[0115]

Claims

1. An adhesive resin composition comprising: (a) A resin containing (meth)acrylate groups, said resin comprising polycarbonate-based polyurethane acrylate oligomers, (b) Polyfunctional thiols represented by the following formula (2): ,and (c) Latent curing agent.

2. The adhesive resin composition according to claim 1, further comprising: (d) at least one polymerization inhibitor selected from N-nitrosophenylhydroxylamine aluminum, triphenyl phosphite, p-methoxyphenol and hindered phenols.

3. The adhesive resin composition according to claim 1 or 2, further comprising: (e) an anionic polymerization inhibitor, said anionic polymerization inhibitor being an organic acid.

4. The adhesive resin composition according to claim 1 or 2, further comprising: (f) a photopolymerization initiator.

5. The adhesive resin composition according to claim 1 or 2, further comprising: (g) epoxidized polybutadiene.

6. The adhesive resin composition according to claim 1 or 2, used for assembling a camera module.

7. A cured product obtainable by curing an adhesive resin composition according to any one of claims 1 to 6.

8. Use of an adhesive resin composition for assembling a camera module, said adhesive resin composition comprising: (a) A resin containing (meth)acrylate groups, said resin comprising polycarbonate-based polyurethane acrylate oligomers, (b) Polyfunctional thiols represented by the following formula (2): ,and (c) Latent curing agent.

9. A method for bonding a camera module lens mount and a camera module substrate on which an imaging element is fixed, the method comprising bonding the lens mount and the substrate using an adhesive resin composition; The adhesive resin composition comprises: (a) A resin containing (meth)acrylate groups, said resin comprising polycarbonate-based polyurethane acrylate oligomers, (b) Polyfunctional thiols represented by the following formula (2): ,and (c) Latent curing agent.

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