JP7007592B2 - Cationic Curable Adhesive Compositions for Camera Modules, Cured Products and Bonds - Google Patents

Description

The present invention relates to a cationically curable adhesive composition for a camera module, a cured product of the composition, and a bonded body using the composition.

Conventionally, a cationically curable composition containing an epoxy resin or the like is excellent in adhesive strength, sealing property, high strength, heat resistance, electrical properties, and chemical resistance, and therefore, therefore, an adhesive, a sealing agent, a potting agent, and a coating. It has been used in various applications such as agents and conductive pastes. Further, the target is wide-ranging, and particularly in electronic devices, it is used for semiconductors, liquid crystal displays, organic electroluminescence, flat panel displays such as touch panels, hard disk devices, mobile terminal devices, camera modules and the like.

According to JP-A-2009-186756, JP-A-2016-404268, JP-A-2016-110067, JP-A-2016-122055 (corresponding to International Publication No. 2016-103687), the camera module Adhesion points include between an image sensor such as CMOS or CCD and a substrate, between a cut filter and a substrate, between a substrate and a housing, between a housing and a cut filter, and between a housing and a lens unit. The interval etc. can be mentioned.

International Publication No. 2005/05/9002 discloses a cationically curable epoxy adhesive composition for semiconductor device packages such as CMOS containing an epoxy resin component, a photocation initiator, a thermal cation initiator, and a filler. ing.

Engineering plastics such as LCP (liquid crystal polymer), PPS (polyphenylene sulfide), and polycarbonate are used as materials for the housing and lens unit in the camera module. Engineering plastics are plastics having excellent tensile strength even when left in an environment of 100 ° C. or higher for a long time. The cationically curable epoxy adhesive composition disclosed in International Publication No. 2005/05/9002 was not satisfactory as an adhesive for camera modules because of its poor adhesiveness to engineering plastics. Further, the cationically polymerizable adhesive composition for a camera module is required to have low temperature curability (for example, 100 ° C. or lower). This is because there is a concern that the plastic lens or the like used in the camera module may be damaged under high-temperature curing conditions. According to the examples, the cationically curable epoxy adhesive composition of the International Publication No. 2005/059002 pamphlet is disclosed to be cured by heating at 120 ° C. after irradiation with ultraviolet rays, and is also satisfactory from the viewpoint of low temperature curability. It wasn't.

Therefore, an object of the present invention is to provide a cationically curable adhesive composition having both low temperature curability and adhesiveness to engineering plastics (particularly LCP).

The present invention overcomes the above-mentioned conventional problems. That is, the present invention is as follows.

[1] Component (A): a cationically polymerizable resin containing at least one selected from the group consisting of an alicyclic epoxy resin and a hydride epoxy resin, component (B): a thermal cationic polymerization initiator, and (C). Ingredients: A camera comprising at least one of a rubber filler or a styrene-based filler containing at least one selected from the group consisting of diene-based rubbers and (meth) acrylic rubbers (excluding silicone-acrylic copolymers). Cationic curable adhesive composition for modules.

[2] The component (B) is contained in an amount of 0.1 to 30 parts by mass and the component (C) is contained in an amount of 0.5 to 20 parts by mass with respect to 100 parts by mass of the component (A) [2]. 1] The cationically curable adhesive composition for a camera module.

[3] The camera module according to [1] or [2], wherein the component (B) is a thermal cationic polymerization initiator containing a salt composed of a tetrakis (pentafluorophenyl) borate anion and a cation. Cationic curable adhesive composition.

[4] The cationically curable adhesive composition for a camera module according to any one of [1] to [3], which further contains a photocationic polymerization initiator as a component (D).

[5] The cationic curing for a camera module according to [4], wherein the component (D) contains at least one of an aromatic iodonium-based photocationic polymerization initiator or an aromatic sulfonium-based photocationic polymerization initiator. Sexual adhesive composition.

[6] A cured product of the cationically curable adhesive composition for a camera module according to any one of [1] to [5].

[7] A bonded body obtained by adhering two or more adherends using the cationically curable adhesive composition for a camera module according to any one of [1] to [5].

The cationically curable adhesive composition for a camera module (hereinafter, also simply referred to as a composition) according to an embodiment of the present invention is selected from the group consisting of the component (A): an alicyclic epoxy resin and a hydride epoxy resin. A group consisting of a cationically polymerizable resin containing at least one of them, a component (B): a thermal cationic polymerization initiator, and a component (C): a diene rubber and a (meth) acrylic rubber (excluding a silicone / acrylic copolymer). Includes at least one of a rubber filler or a styrene-based filler containing at least one selected from the above. The cationically curable adhesive composition for a camera module having this structure can have both low-temperature curability (for example, 100 ° C. or lower) and adhesiveness to engineering plastics (particularly LCP).

In addition, in this specification, "X to Y" is used in the meaning which includes the numerical values (X and Y) described before and after it as a lower limit value and the upper limit value. Unless otherwise specified, operations and measurements of physical properties are performed under the conditions of room temperature (20 to 25 ° C.) / relative humidity of 40 to 50%.

Hereinafter, the present invention will be described in detail.

<Ingredient (A)>
The component (A) of the present invention is a cationically polymerizable resin containing at least one selected from the group consisting of an alicyclic epoxy resin and a hydrogenated epoxy resin. (A) When the component is not contained, the low temperature curability is inferior (see Comparative Example 1 described later). Here, the cationically polymerizable resin is a compound that undergoes a crosslinking reaction depending on the cationic species generated from the cationic polymerization initiator. For example, when an epoxy resin and a thermal cationic polymerization initiator are used, ring-opening polymerization of the epoxy group is caused by adding the cation species generated from the thermal cationic polymerization initiator to the epoxy group by heating, and the epoxy resin is crosslinked. do. The hydrogenated epoxy resin means a compound obtained by nuclear hydrogenation of the aromatic ring of an aromatic epoxy resin. These can be used alone or in combination of two or more. Above all, from the viewpoint of further enhancing the adhesiveness to engineering plastics (particularly LCP), the component (A) preferably contains a hydrogenated epoxy resin.

The alicyclic epoxy resin is not particularly limited, but for example, 3', 4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, 3,4-epoxycyclohexylmethyl (3', 4'-epoxy) cyclohexane. Carboxylate, ε-caprolactone modified 3', 4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, bis (3,4-epoxycyclohexyl) adipate, 1,2-epoxy-4-vinylcyclohexane, 1,4 -Cyclohexanedimethanol diglycidyl ether, epoxyethyldivinylcyclohexane, diepoxyvinylcyclohexane, 1,2,4-triepoxyethylcyclohexane, limonendioxide, alicyclic epoxy group-containing silicone oligomer and the like can be mentioned. These can be used alone or in combination of two or more. Of these, 3', 4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate is particularly preferable from the viewpoint of further improving the effect of the present invention.

The commercial product of the alicyclic epoxy resin is not particularly limited, but for example, celloxide 2081, celloxide 2021P, cellophide 2000, celloxide 3000, EHPE3150 (manufactured by Daicel Co., Ltd.), TTA21 (manufactured by Jiangsu TeraChem), and Ricaresin DME-100. (Manufactured by Shin-Nippon Rika Co., Ltd.), X-40-2670, X-22-169AS, X-22-169B (manufactured by Shin-Etsu Chemical Co., Ltd.), etc., but are not limited thereto.

The hydrided epoxy resin is not particularly limited, but for example, a hydride bisphenol A type epoxy resin, a hydride bisphenol F type epoxy resin, a hydride bisphenol E type epoxy resin, and a hydride bisphenol A type alkylene oxide adduct di. Examples thereof include glycidyl ether, diglycidyl ether as an alkylene oxide adduct of hydride bisphenol F, hydrided phenol novolak epoxy resin, hydride cresol novolak epoxy resin, etc., and since they are particularly excellent in low temperature curability, hydrided bisphenol A type epoxy Resins, bisphenol F-type epoxy resins hydride, bisphenol E hydrides epoxy resins are preferable, and bisphenol A hydrides epoxy resins are particularly preferable. These can be used alone or in combination of two or more.

Commercially available products of hydride bisphenol A type epoxy resin include, for example, YX-8000, YX-8034 (manufactured by Mitsubishi Chemical Corporation), EXA-7015 (manufactured by DIC Corporation), ST-3000 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.). , Rica Resin HBE-100 (New Japan Rika Co., Ltd.), EX-252 (Nagase Chemtex Co., Ltd.) and the like. Examples of commercially available products of hydrogenated bisphenol F type epoxy resin include YL-6753 (manufactured by Mitsubishi Chemical Corporation).

From the viewpoint of further improving the effect of the present invention, it is preferable to use an alicyclic epoxy resin and a hydrogenated epoxy resin in combination as the component (A), and the mass ratio thereof (alicyclic epoxy resin: hydrogenated epoxy resin) is It is preferably 5:95 to 70:30, more preferably 15:85 to 50:50, and even more preferably 25:75 to 40:60.

From the viewpoint of further improving the effect of the present invention, the epoxy equivalent of the component (A) is preferably 50 to 500 g / eq, and more preferably 100 to 250 g / eq.

<Ingredient (B)>
The component (B) of the present invention is a thermal cationic polymerization initiator, which is a compound that generates a cationic species by heating. By containing the component (B), even when an engineering plastic having low light transmission is selected as the adherend, excellent adhesiveness can be exhibited by thermosetting.

The component (B) is not particularly limited, but is, for example, a thermal cationic polymerization initiator (B1) containing a salt composed of a hexafluoroantimonate anion and a cation, and a thermal cationic polymerization containing a salt composed of a hexafluorophosphate anion and a cation. Examples thereof include a thermal cationic polymerization initiator (B3) containing a salt consisting of an initiator (B2), a tetrakis (pentafluorophenyl) borate anion and a cation, and among these, tetrakis (pentafluorophenyl) is excellent in low temperature curability. ) A thermal cationic polymerization initiator (B3) containing a salt consisting of a borate anion and a cation is preferable. Examples of the cation include a quaternary ammonium cation, a sulfonium ion in which at least one of the three groups bonded to the sulfur atom is an alkyl group having 1 to 8 carbon atoms. These may be used alone or in combination of two or more.

As the thermal cationic polymerization initiator (B3) containing a salt composed of a tetrakis (pentafluorophenyl) borate anion and a cation, tetrakis (B3) is preferably used from the viewpoint of achieving both lower temperature curability and adhesion to engineering plastics. Examples thereof include a thermal cationic polymerization initiator containing a salt consisting of a pentafluorophenyl) borate anion and a quaternary ammonium cation.

Examples of commercially available products of the thermal cationic polymerization initiator (B1) containing a salt composed of the hexafluoroantimonate anion and a cation include SI-60L, SI-80L, SI-100L (manufactured by Sanshin Chemical Industry Co., Ltd.) and the like. Be done. Alternatively, SI-110L, SI-180L, SI-B2A, SI-B3A (manufactured by Sanshin Chemical Industry Co., Ltd.) are examples of the thermal cationic polymerization initiator (B2) containing a salt composed of the hexafluorophosphate anion and a cation. Can be mentioned. Further, as a commercially available product of the thermal cationic polymerization initiator (B3) containing a salt composed of the tetrakis (pentafluorophenyl) borate anion and a cation, for example, CXC-1821 (manufactured by King Industries) and the like can be mentioned.

The blending amount of the component (B) in the cationically curable adhesive composition of the present invention is not particularly limited, but is preferably 0.1 to 30 parts by mass with respect to 100 parts by mass of the component (A), more preferably. Is 0.3 to 15 parts by mass, more preferably 0.5 to 5 parts by mass, and particularly preferably 1 to 3 parts by mass. If it is 0.1 part by mass or more, the low temperature curability is good, and if it is 30 parts by mass or less, the storage stability is good.

<Ingredient (C)>
The component (C) of the present invention is at least one of a rubber filler or a styrene-based filler containing at least one selected from the group consisting of diene-based rubber and (meth) acrylic rubber (excluding silicone / acrylic copolymer). be. The component (C) has a remarkable effect that, when combined with the other components of the present invention, it does not inhibit the curing of the composition (that is, maintains low temperature curability) and has excellent adhesiveness to engineering plastics (particularly LCP). Bring.

Here, the rubber filler refers to a rubber-like elastic body at 25 ° C., and examples thereof include those having a glass transition point (Tg) of less than 25 ° C. Since engineering plastics have relatively high crystallinity, when the adhesive composition disclosed in International Publication No. 2005/059002 is applied, stress acts on the adhesive surface and sufficient adhesiveness cannot be exhibited. it is conceivable that. On the other hand, it is considered that the composition according to the present invention can exhibit excellent adhesiveness by relaxing the stress by containing the rubber filler.

Examples of the diene rubber include polyisoprene rubber, polybutadiene rubber, styrene butadiene rubber, acrylonitrile butadiene rubber, polychloroprene rubber, and hydrogenated products thereof. From the viewpoint of further improving the adhesiveness to engineering plastics, among them, Polybutadiene rubber, styrene butadiene rubber, and acrylonitrile butadiene rubber are preferable, polybutadiene rubber or acrylonitrile butadiene rubber is more preferable, and polybutadiene rubber is particularly preferable. These may be used alone or in combination of two or more.

The (meth) acrylic rubber refers to a polymer obtained by polymerizing a (meth) acrylic acid ester alone or together with a monomer copolymerizable therewith (excluding silicone / acrylic copolymers), for example. Examples thereof include acrylic rubber such as an acrylic acid ester / 2-chloroethyl vinyl ether copolymer (ACM) and an acrylic acid ester / acrylonitrile copolymer (ANM). Here, the reason why the silicone-acrylic copolymer is excluded from the definition of (meth) acrylic rubber is that sufficient adhesiveness to engineering plastics cannot be obtained (see Comparative Example 5 described later).

Examples of the (meth) acrylic acid ester include ethyl (meth) acrylate, butyl (meth) acrylate, and methoxyethyl (meth) acrylate. Examples of the monomer copolymerizable with the (meth) acrylic acid ester include 2-chloroethyl vinyl ether and acrylonitrile.

The component (C) preferably contains at least one of polybutadiene rubber and acrylic rubber, and more preferably polybutadiene rubber, from the viewpoint of further improving the adhesiveness to engineering plastics.

The styrene-based filler has a glass transition point (Tg) of 50 ° C., which is obtained by polymerizing at least one kind of styrene derivative (for example, styrene, α-methylstyrene, divinylbenzene) with a monomer that can be polymerized or copolymerized therewith. The above (upper limit is, for example, 200 ° C. or lower) polystyrene-based filler. Specific examples of the styrene-based filler include a styrene-glycidyl methacrylate copolymer, a styrene-divinylbenzene copolymer, and the like, and a styrene-divinylbenzene copolymer is preferable. Examples of commercially available products include Marproof G-1005S (manufactured by NOF CORPORATION) and Fine Pearl PB-3006E (manufactured by Matsuura Co., Ltd.). These may be used alone or in combination of two or more.

By pre-dispersing the component (C) of the present invention in the component (A) of the present invention, it is possible to facilitate the dispersion in the composition.

The average particle size of the component (C) is preferably 0.01 to 5 μm, more preferably 0.05 to 1 μm, and particularly preferably 0.1 to 0.6 μm. When it is 0.01 μm or more, it is preferable because the viscosity of the adhesive composition does not increase and the workability is good, and when it is 5 μm or less, it is preferable because the adhesiveness to engineering plastics is excellent. The method for measuring the average particle size is a laser diffraction / scattering method (50% volume average particle size).

The amount of the component (C) added is preferably 0.1 to 50 parts by mass, more preferably 0.3 to 30 parts by mass with respect to 100 parts by mass of the component (A), and is an engineering plastic ( In particular, from the viewpoint of further enhancing the adhesiveness to LCP), it is more preferably 0.5 to 20 parts by mass, and even more preferably 2 to 12 parts by mass. Among them, the lower limit value is preferably 4 parts by mass or more, 5 parts by mass or more or 6 parts by mass or more, and the upper limit value is preferably 10 parts by mass or less, 9 parts by mass or less or 8 parts by mass or less.

<(D) component>
The present invention may further contain a photocationic polymerization initiator as the component (D) as long as the characteristics of the present invention are not impaired. By further containing the component (D), the deep portion can be cured by heat after being temporarily cured by light. Therefore, a cured product cross-linked to a deep part can be obtained, and the adhesiveness can be exhibited more stably. The photocationic polymerization initiator is a compound that generates a cationic species by irradiation with active energy rays. The component (D) is not particularly limited, but for example, when a salt containing a tetrakis (pentafluorophenyl) borate anion is selected as the component (B), both photocurability, thermosetting and storage stability are improved. From the viewpoint, it is preferable to contain at least one of the aromatic iodonium-based photocationic polymerization initiator and the aromatic sulfonium-based photocationic polymerization initiator. These may be used alone or in combination of two or more. Above all, it is preferable to contain an aromatic iodonium-based photocationic polymerization initiator.

Examples of the aromatic sulfonium-based photocationic polymerization initiator include a photocationic polymerization initiator containing a sulfonium ion in which all three groups bonded to the sulfur atom are aryl groups (for example, phenyl groups). Further, the aromatic iodonium-based photocationic polymerization initiator includes a photocationic polymerization initiator containing an iodonium ion in which two groups bonded to an iodine atom are aryl groups (for example, a phenyl group). Initiators that generate cation species by either heat or active energy rays shall be classified as component (B) in the present invention.

Examples of the aromatic sulfonium-based photocationic polymerization initiator include triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium tetrakis (pentafluorophenyl) borate, and 4,4'-bis [diphenylsulfonio]. Diphenylsulfide-bishexafluorophosphate, 4,4'-bis [di (β-hydroxyethoxy) phenylsulfonio] diphenylsulfide-bishexafluoroantimonate, 4,4'-bis [di (β-hydroxyethoxy) phenyl Sulfonio] diphenyl sulfide-bishexafluorophosphate, 7- [di (p-toluyl) sulfonate] -2-isopropylthioxanthone hexafluoroantimonate, 7- [di (p-toluyl) sulfonate] -2-isopropylthioxanthone tetrakis ( Pentafluorophenyl) borate and the like can be mentioned. It is not limited to these. These aromatic sulfonium-based photocationic polymerization initiators may be used alone or in combination.

Commercially available aromatic sulfonium-based photocationic polymerization initiators include SP-150, SP-170, SP-172 (manufactured by ADEKA Co., Ltd.), CPI-100P, CPI-101A, CPI-110B, CPI-200K, CPI. -210S (manufactured by Sun Appro Co., Ltd.), T1608, T1609, T2041, T2042 (manufactured by Tokyo Kasei Kogyo Co., Ltd.), UVI-6990, UVI-6974 (manufactured by Union Carbide), DTS-200 (manufactured by Midori Chemical Co., Ltd.), etc. Can be mentioned.

Examples of the aromatic iodinenium-based photocationic polymerization initiator include diphenyliodonium tetrakis (pentafluorophenyl) borate, diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, di (4-nonylphenyl) iodinenium hexafluorophosphate, 4-. Examples thereof include methylphenyl-4- (1-methylethyl) phenyliodonium tetrakis (pentafluorophenyl) borate and the like. Of these, 4-methylphenyl-4- (1-methylethyl) phenyliodonium tetrakis (pentafluorophenyl) borate is preferred. These may be used alone or in combination.

Commercially available aromatic iodinenium-based photocationic polymerization initiators include Irgacure 250 (manufactured by BASF), PI-2074 (manufactured by Rhodia), B2380, B2381, D2238, D2248, D2253, and I0591 (Tokyo Chemical Industry Co., Ltd.). WPI-113, WPI-116, WPI-169, WPI-170, WPI-124 (manufactured by Wako Pure Chemical Industries, Ltd.) and the like.

The blending amount of the component (D) in the cationically curable adhesive composition of the present invention is not particularly limited, but is preferably 0.1 to 30 parts by mass with respect to 100 parts by mass of the component (A), more preferably. Is 0.5 to 15 parts by mass, and even more preferably 1 to 5 parts by mass. If it is 0.1 part by mass or more, the photocurability is good, and if it is 30 parts by mass or less, it is easily dissolved in the component (A).

<Arbitrary ingredient>
Further, the cationically curable adhesive composition of the present invention includes aromatic epoxy resins, oxetane compounds, vinyl ether compounds, pigments, colorants such as dyes, sensitizers, and silane couplings as long as the characteristics of the present invention are not impaired. Agents, polyol compounds, peroxides, thiol compounds, storage stabilizers, calcium carbonate, magnesium carbonate, titanium oxide, magnesium hydroxide, talc, silica, alumina, glass, aluminum hydroxide, boron nitride, aluminum nitride, magnesium oxide, etc. Inorganic filler with an average particle size of 0.001 to 100 μm, conductive particles such as silver, flame retardant, plasticizer, organic solvent, phenolic antioxidant, antioxidant such as phosphorus antioxidant, photostable Agents, UV absorbers, defoaming agents, foaming agents, mold release agents, leveling agents, leology control agents, tackifiers, curing retarders, polyimide resins, polyamide resins, phenoxy resins, cyanate esters, polyvinyl butyral resins, etc. The additive of the above may be blended in an appropriate amount. By adding these, a cationically curable adhesive composition having more excellent resin strength, adhesive strength, flame retardancy, thermal conductivity, workability, etc. and a cured product thereof can be obtained. Above all, from the viewpoint of further improving the adhesiveness to engineering plastics, it is preferable to further contain a silane coupling agent.

In the present invention, in addition to the alicyclic epoxy resin and the hydrogenated epoxy resin of the component (A), an aromatic epoxy resin, an oxetane compound, a vinyl ether compound and the like can be used in combination.

Examples of the aromatic epoxy resin include aromatic bisphenol A type epoxy resin, aromatic bisphenol F type epoxy resin, aromatic bisphenol E type epoxy resin, aromatic bisphenol A type alkylene oxide adduct diglycidyl ether, and aromatic bisphenol F. Diglycidyl ether of type alkylene oxide adduct, diglycidyl ether of aromatic bisphenol E type alkylene oxide adduct, aromatic novolac type epoxy resin, urethane modified aromatic epoxy resin, nitrogen-containing aromatic epoxy resin, polybutadiene or nitrile Examples thereof include rubber-modified aromatic epoxy resins containing butadiene rubber (NBR) and the like. These can be used alone or in combination of two or more.

Commercially available aromatic epoxy resins include, for example, jER825, 827, 828, 828EL, 828US, 828XA, 834, 806, 806H, 807, 604, 630 (manufactured by Mitsubishi Chemical Corporation), EPICLON830, EXA-830LVP, EXA- 850CRP, 835LV, HP4032D, 703, 720, 726, HP820, N-660, N-680, N-695, N-655-EXP-S, N-665-EXP-S, N-685-EXP-S, N-740, N-775, N-865 (manufactured by DIC Corporation), EP4100, EP4000, EP4080, EP4085, EP4088, EP4100HF, EP4901HF, EP4000S, EP4000L, EP4003S, EP4010S, EP4010L (manufactured by ADEKA Corporation), Denacol EX614B , EX411, EX314, EX201, EX212, EX252 (manufactured by Nagase ChemteX Corporation) and the like, but are not limited thereto. These may be used alone or in combination of two or more.

Examples of the oxetane compound include 3-ethyl-3-hydroxymethyloxetane, 3- (meth) allyloxymethyl-3-ethyloxetane, (3-ethyl-3-oxetanylmethoxy) methylbenzene, and 4-fluoro- [1-. (3-Ethyl-3-oxetanylmethoxy) methyl] benzene, [1- (3-ethyl-3-oxetanylmethoxy) ethyl] phenyl ether, isobutoxymethyl (3-ethyl-3-oxetanylmethyl) ether, 2-ethylhexyl (3-Ethyl-3-oxetanylmethyl) ether, ethyldiethylene glycol (3-ethyl-3-oxetanylmethyl) ether, tetrahydrofurfuryl (3-ethyl-3-oxetanylmethyl) ether, tetrabromophenyl (3-ethyl-3) -Oxetanylmethyl) ether, 2-tetrabromophenoxyethyl (3-ethyl-3-oxetanylmethyl) ether, pentachlorophenyl (3-ethyl-3-oxetanylmethyl) ether, pentabromophenyl (3-ethyl-3-oxetanylmethyl) ether ) Ether, ethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, triethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, tetraethylene glycolbis (3-ethyl-3-oxetanylmethyl) ether, Trimethylol propanthris (3-ethyl-3-oxetanylmethyl) ether, pentaerythritol tris (3-ethyl-3-oxetanylmethyl) ether, pentaerythritol tetrakis (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol tetrakis (3-Ethyl-3-oxetanylmethyl) ether, ditrimethylolpropanetetrakis (3-ethyl-3-oxetanylmethyl) ether and the like can be mentioned. Examples of commercially available products of the oxetane compound include OXT-212, OXT-221, OXT-213, and OXT-101 (manufactured by Toagosei Co., Ltd.). These can be used alone or in combination of two or more.

Examples of the vinyl ether compound include 1,4-butanediol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, tetraethylene glycol divinyl ether, normal propyl vinyl ether, isopropyl vinyl ether, normal butyl vinyl ether, isobutyl vinyl ether, and 2-ethylhexyl vinyl ether. , Cyclohexyl vinyl ether, 2-hydroxyethyl vinyl ether, diethylene glycol monovinyl ether, 4-hydroxybutyl vinyl ether, 2- (2-vinyloxyethoxy) ethyl acrylate, 2- (2-vinyloxyethoxy) ethyl methacrylate and the like. Commercially available products of the vinyl ether compound include NPVE, IPVE, NBVE, IBVE, EHVECHVE (manufactured by Nippon Carbide Industries, Ltd.), HEVE, DEFV, HBVE (manufactured by Maruzen Petrochemical Co., Ltd.), VEEA, VEEM (manufactured by Nippon Shokubai Co., Ltd.). And so on. These can be used alone or in combination of two or more.

As sensitizers, 9-fluorene, antron, dibenzosverone, fluorene, 2-bromofluorene, 9-bromofluorene, 9,9-dimethylfluorene, 2-fluorofluorene, 2-iodofluorene, 2-fluoreneamine, 9-Fluorenol, 2,7-Dibromofluorene, 9-aminofluorene hydrochloride, 2,7-diaminofluorene, 9,9'-spirobi [9H-fluorene], 2-fluorenecarboxyaldehyde, 9-fluorenylmethanol, 2-Acetylfluorene, benzophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethylketal, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ) Ketone, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) Examples thereof include butanone, 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propanone oligomer, nitro compound, dye and the like. The amount added is not particularly limited, but it is necessary to refer to the absorption wavelength and the molar extinction coefficient.

Examples of the silane coupling agent include vinyl group-containing silane coupling agents such as vinyltris (β-methoxyethoxy) silane, vinyltriethoxysilane, and vinyltrimethoxysilane, and (meth) such as γ-methacryloxypropyltrimethoxysilane. Acrylic group-containing silane coupling agent, amino group-containing silane such as N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane Coupling agents and others include γ-mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane and the like. Among these, a glycidyl group-containing silane coupling agent is preferably used, and among the glycidyl group-containing silane coupling agents, 3-glycidoxypropyltrimethoxysilane and 3-glycidoxypropyltriethoxysilane are preferable. These may be used alone or in combination of two or more.

As the polyol compound, it may be added in order to adjust the curing rate and further enhance the adhesive strength. Examples of the polyol compound include ethylene glycol, propylene glycol, 1,4-butanediol, 1,3-butanediol, 1,9-nonanediol, neopentyl glycol, tricyclodecanedimethylol, cyclohexanedimethylol, and tri. Polypolyolpropane, glycerin, hydrogenated polybutadiene polyol, aliphatic polyols such as hydrogenated dimerdiol, diethylene glycol, tripropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, trimethylolpropane polyethoxytriol, glycerin polypropoxytriol, bisphenol A (poly) ether polyol, polyester polyol compound, polycaprolactone polyol compound, polyol compound having a phenolic hydroxyl group, polycarbonate having one or more ether bonds such as A polyethoxydiol, bisphenol F polyethoxydiol, and ditrimethylolpropane. Examples thereof include polycarbonate polyols such as diols.

<Curing method and cured product>
The present invention also provides a cured product of the above-mentioned cationically curable adhesive composition for a camera module. When the cationically curable adhesive composition of the present invention is heat-cured to obtain a cured product, the heating temperature is not particularly limited, but is preferably, for example, a temperature of 45 ° C. or higher and lower than 100 ° C., more preferably 50 ° C. It is above 95 ° C. and below 95 ° C. The heating time is also not particularly limited, but is preferably 5 to 120 minutes, more preferably 10 to 60 minutes, for example. Further, the composition according to the present invention can be cured by irradiation with active energy rays by containing the component (D). Examples of the active energy ray in this case include ultraviolet rays, electron beams, visible rays, and the like, but the active energy rays are not particularly limited. The integrated light amount of the active energy ray is preferably 300 to 100,000 mJ / cm ² , and the wavelength of the active energy ray is preferably 150 to 830 nm, more preferably 200 to 400 nm. As a method for curing the cationically curable adhesive composition of the present invention, active energy ray irradiation and heating may be used in combination.

<Use>
The use of the cationically curable adhesive composition of the present invention is a camera module. The bonding points of the camera module are between the image sensor such as CMOS and CCD and the board, between the cut filter and the board, between the board and the housing, between the housing and the cut filter, and between the housing and the lens. For example, between units. The material of the housing and the lens unit is not particularly limited, and examples thereof include engineering plastics such as LCP (liquid crystal polymer), PPS (polyphenylene sulfide), and polycarbonate because of their excellent moldability. The cured product of the cationically curable adhesive composition of the present invention has excellent adhesiveness to these engineering plastics (particularly LCP). That is, another embodiment of the present invention is a camera module containing a cured product of the cationically curable adhesive composition.

<Joined body>
The present invention also provides a bonded body formed by adhering two or more adherends using the above-mentioned cationically curable adhesive composition for a camera module. The adherend is not particularly limited, and examples thereof include engineering plastics such as LCP, PPS, and polycarbonate, and LCP is preferable. Therefore, a preferred embodiment of the present invention is a bonded body obtained by adhering two or more LCPs using the above-mentioned cationically curable adhesive composition for a camera module.

The present invention will be specifically described below by way of examples, but the present invention is not limited by the following examples.

<Preparation of cationically curable adhesive composition>
Each component was sampled by mass as shown in Table 1 and mixed with a planetary mixer at room temperature for 60 minutes under shading to prepare a cationically curable adhesive composition, and various physical properties were measured as follows.

<Ingredient (A)>
a1: Hydrogenated bisphenol A type epoxy resin (YX8000, epoxy equivalent 205 g / eq, manufactured by Mitsubishi Chemical Corporation)
a2: 3', 4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (seroxide 2021P, epoxy equivalent 137 g / eq, manufactured by Daicel Corporation)
<Comparison component of (A) component>
a'1: Aromatic bisphenol A type epoxy resin (jER807, manufactured by Mitsubishi Chemical Corporation)
<Ingredient (B)>
b1: Thermal cation polymerization initiator containing a salt consisting of a tetrakis (pentafluorophenyl) borate anion and a quaternary ammonium cation (CXC-1821, manufactured by King Industries).
<Ingredient (C)>
c1: Polybutadiene rubber filler with an average particle size of 0.2 μm (Tg less than 25 ° C)
c2: Styrene-butadiene rubber filler with an average particle size of 0.1 μm (Tg less than 25 ° C)
c3: Average particle size 0.3 μm acrylic rubber filler (Tg less than 25 ° C)
c4: Acrylonitrile butadiene rubber filler with an average particle size of 0.3 μm (Tg less than 25 ° C)
c5: Styrene-based filler (Tg100 ° C.) of a styrene-divinylbenzene copolymer having an average particle size of 0.6 μm.
<Comparison component of (C) component>
c'1: Liquid hydroxyl-terminated polyisoprene at 25 ° C (Poly ip (registered trademark), manufactured by Idemitsu Kosan Co., Ltd.)
c'2: Hydroxyl-terminated polybutadiene liquid at 25 ° C (Poly bd (registered trademark), manufactured by Idemitsu Kosan Co., Ltd.)
c'3: Silicone-acrylic copolymer rubber filler with an average particle size of 0.4 μm c'4: Urethane rubber filler with an average particle size of 0.3 μm c'5: Flake-shaped acrylic resin with no rubber elasticity at 25 ° C. (ARUFON (registered trademark) UG-4035, manufactured by Toa Synthetic Co., Ltd.)
<(D) component>
d1: Aromatic iodonium salt-containing photocationic polymerization initiator (PI-2074, manufactured by Rhodia)
<Other ingredients>
Silane coupling agent: 3-glycidoxypropyltrimethoxysilane (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.).

The test methods used in the examples and comparative examples are as follows.

<Low temperature curability test>
0.1 g of each cationically curable adhesive composition was dropped onto a hot plate set at 80 ° C., and after 30 minutes, contact was made with a glass rod having a sharp tip, and the curability of the composition was visually checked based on the following criteria. Evaluated at. If it is ○ in the following criteria, it can be said that the low temperature curability is good. The results are shown in Table 1.

[Evaluation criteria]
◯: There is no deposit on the rod ×: There is a deposit on the rod.

<Adhesion to engineering plastics>
A polytetrafluoroethylene tape is attached to the back of a SUS washer with a hole of 0.5 mm in thickness and 6.1 mm in diameter, and an LCP test piece (made by Polyplastics Co., Ltd.) with a width of 250 mm, a length of 10 mm, and a thickness of 3 mm is attached. It was installed on VECTRA E130i). Next, each cationically curable adhesive composition was applied to the inside of the washer and heated at 80 ° C. for 1 hour to cure. As a result, a test piece in which the LCP test piece and the cured product of the cationically curable adhesive composition were adhered was obtained. Then, the tip strength [N / mm ² ] was measured with a push-pull gauge using the test piece. The results are shown in Table 1.

In the present invention, the chip strength preferable is 6.0 N / m ² or more, more preferably 7.0 N / mm ² or more, still more preferably 8.0 N / mm ² or more, and particularly preferably 10 N / mm. It is mm ² or more (the upper limit is, for example, 20 N / mm ² or less). In addition, "unmeasurable" in Table 1 means that the present test could not be performed because the cationically curable adhesive composition did not cure even when heated at 80 ° C. for 1 hour. do.

From Examples 1 to 11, it can be seen that the cationically curable adhesive composition of the present invention has both low temperature curability (100 ° C. or lower) and adhesiveness to engineering plastics (LCP).

Comparative Example 1 is a composition containing neither an alicyclic epoxy resin or a hydrided epoxy resin, which is an essential component of the component (A) of the present invention, and containing only an aromatic bisphenol A type epoxy resin, but is cured at low temperature. It can be seen that the sex is significantly inferior. Further, Comparative Example 2 is a composition containing no component (C) of the present invention, but it can be seen that the adhesiveness to engineering plastics (LCP) is inferior. Further, in Comparative Examples 3 to 5, instead of the component (C) of the present invention, a hydroxyl-terminated polyisoprene liquid at 25 ° C., a hydroxyl-terminated polybutadiene liquid at 25 ° C., or a silicone / acrylic having an average particle size of 0.4 μm has a copolymer weight. Although it is a composition using a coalescence, it can be seen that the adhesiveness to engineering plastics is inferior. Further, Comparative Example 6 was a composition in which urethane rubber was used instead of the component (C) of the present invention, but the low-temperature curability was significantly inferior. Further, Comparative Example 7 was a composition using a flake-shaped acrylic resin which was not a rubber elastic body at 25 ° C. instead of the component (C) of the present invention, but the low-temperature curability was remarkably inferior.

INDUSTRIAL APPLICABILITY The present invention is a cationically curable adhesive composition having both low-temperature curability and adhesiveness to engineering plastics (particularly LCP), and is industrially useful because it can be applied to an adhesive for a camera module.

The application of the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit of the present invention.

This application is based on Japanese Patent Application No. 2016-225225 filed on November 18, 2016, the disclosure of which is referenced and incorporated as a whole.

Claims (7)

(A) Component: A cationically polymerizable resin containing at least one selected from the group consisting of an alicyclic epoxy resin and a hydrogenated epoxy resin.
Component (B): Thermal cation polymerization initiator containing a salt consisting of tetrakis (pentafluorophenyl) borate anion and cation , and component (C): diene rubber and (meth) acrylic rubber (excluding silicone / acrylic copolymer). ) Containes at least one of a rubber filler or a styrene-based filler containing at least one selected from the group consisting of the above components (A), and 0.5 to 20 parts by mass of the component (C) with respect to 100 parts by mass of the component (A). A cationically curable adhesive composition for a camera module, which comprises a part thereof. The cationically curable adhesive composition for a camera module according to claim 1, wherein the component (B) is contained in an amount of 0.1 to 30 parts by mass with respect to 100 parts by mass of the component (A). The cationic curing for a camera module according to claim 1 or 2, wherein the component (B) is a thermal cationic polymerization initiator containing a salt composed of a tetrakis (pentafluorophenyl) borate anion and a quaternary ammonium cation. Sex adhesive composition. The cationically curable adhesive composition for a camera module according to any one of claims 1 to 3, further comprising a photocationic polymerization initiator as a component (D). The cationic curable adhesive for a camera module according to claim 4, wherein the component (D) contains at least one of an aromatic iodonium-based photocationic polymerization initiator and an aromatic sulfonium-based photocationic polymerization initiator. Composition. A cured product of the cationically curable adhesive composition for a camera module according to any one of claims 1 to 5. A bonded body obtained by adhering two or more adherends using the cationically curable adhesive composition for a camera module according to any one of claims 1 to 5.