WO2018092463A1

WO2018092463A1 - Cationically curable adhesive composition for camera modules, cured product, and assembly

Info

Publication number: WO2018092463A1
Application number: PCT/JP2017/036518
Authority: WO
Inventors: 寛人松岡
Original assignee: 株式会社スリーボンド
Priority date: 2016-11-18
Filing date: 2017-10-06
Publication date: 2018-05-24
Also published as: JP7007592B2; KR102389948B1; CN109963920B; KR20190084947A; CN109963920A; JPWO2018092463A1

Abstract

[Problem] To provide a cationically curable adhesive composition that combines low-temperature curability with adhesiveness to engineering plastics (in particular, LCPs). [Solution] A cationically curable adhesive composition for camera modules, characterized by comprising: an (A) component that is a cationically polymerizable resin comprising at least one selected from the group consisting of alicyclic epoxy resins and hydrogenated epoxy resins; a (B) component that is a thermal cationic polymerization initiator; and a (C) component that is a rubber filler and/or a styrene filler, said rubber filler comprising at least one selected from the group consisting of diene rubbers and (meth)acrylic rubbers (excluding silicone/acrylic copolymers).

Description

Cationic curable adhesive composition for camera module, cured product, and bonded product

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

Conventionally, a cationic curable composition containing an epoxy resin or the like has excellent adhesive strength, sealing properties, high strength, heat resistance, electrical properties, and chemical resistance, and therefore adhesives, sealing agents, potting agents, and coatings. It has been used in various applications such as agents and conductive pastes. In addition, the object is various, and 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 2009-186756 A, JP 2016-044268 A, JP 2016-110067 A, JP 2016-122555 A (corresponding to WO 2016-103687 pamphlet) Adhesion points include between an image sensor such as CMOS and CCD and the substrate, between the cut filter and the substrate, between the substrate and the housing, between the housing and the cut filter, and between the housing and the lens unit. And so on.

WO 2005/059002 discloses a cation curable epoxy adhesive composition for semiconductor device packages such as CMOS, which contains an epoxy resin component, a photocationic initiator, a thermal cation initiator, and a filler. ing.

Engineering materials such as LCP (Liquid Crystal Polymer), PPS (Polyphenylene Sulfide), and Polycarbonate are used for the housing and lens unit of the camera module. An engineering plastic is a plastic that is excellent in tensile strength even when left in an environment of 100 ° C. or higher for a long time. The cationic curable epoxy adhesive composition disclosed in the pamphlet of International Publication No. 2005/059002 is not satisfactory as an adhesive for camera modules because of poor adhesion to engineering plastics. Moreover, low-temperature curability (for example, 100 degrees C or less) is calculated | required by the cationically polymerizable adhesive composition for camera modules. This is because there is a concern about damage to a plastic lens or the like used in the camera module under high-temperature curing conditions. According to the examples, the cationic curable epoxy adhesive composition disclosed in WO 2005/059002 is disclosed to be cured by heating at 120 ° C. after UV irradiation, which is also satisfactory from the viewpoint of low-temperature curability. It wasn't.

Therefore, an object of the present invention is to provide a cationic curable adhesive composition having both low-temperature curability and adhesion 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 cationic polymerizable resin containing at least one selected from the group consisting of an alicyclic epoxy resin and a hydrogenated epoxy resin, (B) component: a thermal cationic polymerization initiator, and (C) Component: Camera comprising at least one of rubber filler or styrene filler including at least one selected from the group consisting of diene rubber and (meth) acrylic rubber (excluding silicone / acrylic copolymer) Cation 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). 1] The cationically curable adhesive composition for camera modules according to [1].

[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 cationic curable adhesive composition for camera modules according to any one of [1] to [3], further comprising a photocationic polymerization initiator as a component (D).

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

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

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

The camera module cationic curable adhesive composition (hereinafter also simply referred to as a composition) according to an embodiment of the present invention is selected from the group consisting of component (A): an alicyclic epoxy resin and a hydrogenated epoxy resin. And (C) component: a diene rubber and a (meth) acrylic rubber (excluding a silicone / acrylic copolymer). It contains at least one of a rubber filler or a styrenic filler containing at least one selected from the above. The cationic curable adhesive composition for a camera module having the configuration can have both low-temperature curability (for example, 100 ° C. or less) and adhesiveness to engineering plastics (particularly LCP).

In the present specification, “X to Y” are used to mean that the numerical values (X and Y) described before and after that are included as the lower limit value and the upper limit value. Unless otherwise specified, operations and physical properties are measured under conditions of room temperature (20 to 25 ° C.) / Relative humidity 40 to 50%.

Hereinafter, the present invention will be described in detail.

<(A) component>
The component (A) of the present invention is a cationically polymerizable resin containing at least one selected from the group consisting of alicyclic epoxy resins and hydrogenated epoxy resins. When (A) component is not included, it is inferior to low-temperature curability (refer comparative example 1 mentioned later). Here, the cation polymerizable resin is a compound that causes a crosslinking reaction by a cation species generated from a cation polymerization initiator. For example, in the case of using an epoxy resin and a thermal cationic polymerization initiator, the cationic species generated from the thermal cationic polymerization initiator by heating is added to the epoxy group, thereby causing ring-opening polymerization of the epoxy group and crosslinking the epoxy resin. To do. The hydrogenated epoxy resin means a compound obtained by nuclear hydrogenation of an aromatic ring of an aromatic epoxy resin. These can be used alone or in combination of two or more. Especially, it is preferable that (A) component contains a hydrogenated epoxy resin from a viewpoint of further improving the adhesiveness with respect to engineering plastics (especially LCP).

The alicyclic epoxy resin is not particularly limited. 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, limonene dioxide, alicyclic epoxy group-containing silicone Oligomer, and the like. These can be used alone or in combination of two or more. Among these, 3 ′, 4′-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate is particularly preferable from the viewpoint of further improving the effects of the present invention.

Although it does not specifically limit as a commercial item of an alicyclic epoxy resin, For example, Celoxide 2081, Celoxide 2021P, Celoxide 2000, Celoxide 3000, EHPE3150 (made by Daicel Corporation), TTA21 (made by Jiangsu TetraChem), Rica Resin DME-100 (Manufactured by Shin Nippon Chemical Co., Ltd.), X-40-2670, X-22-169AS, X-22-169B (manufactured by Shin-Etsu Chemical Co., Ltd.), and the like, but are not limited thereto.

The hydrogenated epoxy resin is not particularly limited. For example, hydrogenated bisphenol A type epoxy resin, hydrogenated bisphenol F type epoxy resin, hydrogenated bisphenol E type epoxy resin, hydrogenated bisphenol A type alkylene oxide adduct Examples include glycidyl ether, diglycidyl ether of hydrogenated bisphenol F alkylene oxide adduct, hydrogenated phenol novolak epoxy resin, hydrogenated cresol novolac epoxy resin, etc. Resin, hydrogenated bisphenol F type epoxy resin, hydrogenated bisphenol E type epoxy resin are preferable, and hydrogenated bisphenol A type epoxy resin is particularly preferable. These can be used alone or in combination of two or more.

Examples of commercially available hydrogenated bisphenol A type epoxy resins include YX-8000, YX-8034 (Mitsubishi Chemical Corporation), EXA-7015 (DIC Corporation), ST-3000 (Nippon Steel & Sumikin Chemical Co., Ltd.). Rica Resin HBE-100 (Shin Nihon Rika Co., Ltd.), EX-252 (Nagase ChemteX Corporation), and the like. Examples of commercially available hydrogenated bisphenol F-type epoxy resins include YL-6753 (manufactured by Mitsubishi Chemical Corporation).

From the viewpoint of further improving the effects 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 (alicyclic epoxy resin: hydrogenated epoxy resin) is: 5:95 to 70:30 is preferred, 15:85 to 50:50 is more preferred, and 25:75 to 40:60 is even more preferred.

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, more preferably 100 to 250 g / eq.

<(B) component>
(B) component of this invention is a thermal cationic polymerization initiator, and is a compound which generate | occur | produces a cationic seed | species by heating. By containing the component (B), even when an engineering plastic having low light transmittance is selected as the adherend, excellent adhesiveness can be exhibited by thermosetting.

Although it does not specifically limit as (B) component, For example, the thermal cationic polymerization initiator (B1) containing the salt which consists of a hexafluoroantimonate anion and a cation, The thermal cationic polymerization containing the salt which consists of a hexafluorophosphate anion and a cation Examples include an initiator (B2), a thermal cationic polymerization initiator (B3) containing a salt composed of a tetrakis (pentafluorophenyl) borate anion and a cation. Among these, tetrakis (pentafluorophenyl) is excellent in low-temperature curability. ) A thermal cationic polymerization initiator (B3) containing a salt composed of a borate anion and a cation is preferred. Examples of the cation include a quaternary ammonium cation and 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, preferably, tetrakis ( And a thermal cationic polymerization initiator containing a salt comprising a pentafluorophenyl) borate anion and a quaternary ammonium cation.

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

The blending amount of the component (B) in the cationic curable adhesive composition of the present invention is not particularly limited, but is preferably 0.1 to 30 parts by weight, more preferably 100 parts by weight of the component (A). Is 0.3 to 15 parts by mass, still more preferably 0.5 to 5 parts by mass, and particularly preferably 1 to 3 parts by mass. If it is 0.1 parts 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.

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

Here, the rubber filler means a rubber-like elastic body at 25 ° C., and examples thereof include a glass transition point (Tg) of less than 25 ° C. Since engineering plastics have relatively high crystallinity, when the adhesive composition disclosed in the pamphlet of International Publication No. 2005/059002 is applied to this, stress is applied to the bonding surface and sufficient adhesiveness cannot be expressed. it is conceivable that. On the other hand, it is considered that the composition according to the present invention contains a rubber filler, so that the stress is relaxed and excellent adhesiveness can be expressed.

Examples of the diene rubber include polyisoprene rubber, polybutadiene rubber, styrene butadiene rubber, acrylonitrile butadiene rubber, polychloroprene rubber, and hydrogenated ones thereof. From the viewpoint of further improving adhesion to engineering plastics, 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 individually by 1 type and may use 2 or more types together.

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

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

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

Styrenic fillers have a glass transition point (Tg) of 50 ° C. obtained by polymerizing at least one styrene derivative (for example, styrene, α-methylstyrene, divinylbenzene) together with a monomer copolymerizable therewith. Above (upper limit is, for example, 200 ° C. or less) polystyrene filler. Specific examples of the styrenic filler include styrene-glycidyl methacrylate copolymer and styrene-divinylbenzene copolymer, and 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 Corporation). These may be used alone or in admixture of two or more.

The component (C) of the present invention can be easily dispersed in the composition by previously dispersing it in the component (A) of the present invention.

The average particle diameter 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 the thickness is 0.01 μm or more, the viscosity of the adhesive composition does not increase and the workability is good, and when it is 5 μm or less, the adhesiveness to engineering plastic is excellent. The method for measuring the average particle diameter is a laser diffraction / scattering method (50% volume average particle diameter).

The amount of component (C) added is preferably 0.1 to 50 parts by weight, more preferably 0.3 to 30 parts by weight, based on 100 parts by weight of component (A). In particular, from the viewpoint of further improving the adhesion to LCP), it is more preferably 0.5 to 20 parts by mass, and even more preferably 2 to 12 parts by mass. Especially, as a lower limit, 4 mass parts or more, 5 mass parts or more, or 6 mass parts or more are preferable, and as an upper limit, 10 mass parts or less, 9 mass parts or less, or 8 mass parts or less are preferable.

<(D) component>
In the range which does not impair the characteristic of this invention, this invention may contain a photocationic polymerization initiator further as (D) component. (D) By further containing a component, after making it harden | cure temporarily with light, a deep part can be hardened with a heat | fever. Therefore, the hardened | cured material bridge | crosslinked to the deep part is obtained, and adhesiveness can be expressed more stably. The cationic photopolymerization initiator is a compound that generates cationic species upon irradiation with active energy rays. The component (D) is not particularly limited. 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 include at least one of an aromatic iodonium-based photocationic polymerization initiator or an aromatic sulfonium-based photocationic polymerization initiator. These may be used independently and 2 or more types may be used together. Among these, it is preferable to include 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 a sulfur atom are aryl groups (for example, a phenyl group). Examples of the aromatic iodonium-based photocationic polymerization initiator include a photocationic polymerization initiator containing an iodonium ion in which two groups bonded to an iodine atom are an aryl group (for example, a phenyl group). In addition, the initiator which generate | occur | produces a cationic seed | species by both a heat | fever and an active energy ray shall be classified into (B) component in this invention.

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

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

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

Commercially available aromatic iodonium-based photocationic polymerization initiators include Irgacure 250 (manufactured by BASF), PI-2074 (manufactured by Rhodia), B2380, B2381, D2238, D2248, D2253, 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 cationic curable adhesive composition of the present invention is not particularly limited, but is preferably 0.1 to 30 parts by mass, more preferably 100 parts by mass of the component (A). Is 0.5 to 15 parts by mass, and more preferably 1 to 5 parts by mass. If it is 0.1 mass part or more, photocurability will become favorable, and if it is 30 mass parts or less, it will become easy to melt | dissolve in the said (A) component.

<Optional component>
Furthermore, the cationic curable adhesive composition of the present invention includes an aromatic epoxy resin, an oxetane compound, a vinyl ether compound, a colorant such as a pigment and a dye, a sensitizer, and a silane coupling as long as the characteristics of the present invention are not impaired. Agent, polyol compound, peroxide, thiol compound, storage stabilizer, 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, light stability Agent, UV absorber, antifoaming agent, foaming agent, mold release agent, leveling agent, rheology control agent, adhesive Agents, retarders, polyimide resins, polyamide resins, phenoxy resins, cyanate esters, additives such as polyvinyl butyral resin may be appropriate amount. With these additions, a cationic curable adhesive composition having excellent resin strength, adhesive strength, flame retardancy, thermal conductivity, workability, and the like and a cured product thereof can be obtained. Especially, it is preferable that a silane coupling agent is further included from a viewpoint of the further improvement of the adhesiveness with respect to an engineering plastic.

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

Aromatic epoxy resins 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. Type alkylene oxide adduct diglycidyl ether, aromatic bisphenol E type alkylene oxide adduct diglycidyl ether, aromatic novolac 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.

Examples of commercially available aromatic epoxy resins include jER825, 827, 828, 828EL, 828US, 828XA, 834, 806, 806H, 807, 604, 630 (manufactured by Mitsubishi Chemical Corporation), EPICLON 830, 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 (stocks) Company Ltd. ADEKA), Denacol EX614B, EX411, EX314, EX201, EX212, EX252 (manufactured by Nagase Chemtex Co., Ltd.), and the can be mentioned but not limited thereto. These may be used alone or in admixture of two or more.

Examples of the oxetane compound include 3-ethyl-3-hydroxymethyloxetane, 3- (meth) allyloxymethyl-3-ethyloxetane, (3-ethyl-3-oxetanylmethoxy) methylbenzene, 4-fluoro- [1- (3-Ethyl-3-oxetanylmethoxy) methyl] benzene, [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 -Oxetanilme ) Ether, 2-tetrabromophenoxyethyl (3-ethyl-3-oxetanylmethyl) ether, pentachlorophenyl (3-ethyl-3-oxetanylmethyl) ether, pentabromophenyl (3-ethyl-3-oxetanylmethyl) ether , Ethylene glycolose bis (3-ethyl-3-oxetanylmethyl) ether, triethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, tetraethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, trimethylol Propane tris (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, ditrimethylolpropane tetrakis (3-ethyl-3-oxetanylmethyl) ether. Examples of commercially available oxetane compounds include OXT-212, OXT-221, OXT-213, OXT-101 (manufactured by Toa Gosei 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, 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 compounds include NPVE, IPVE, NBVE, IBVE, EHVECHVE (manufactured by Nippon Carbide Industries Co., Ltd.), HEVE, DEGV, HBVE (manufactured by Maruzen Petrochemical Co., Ltd.), VEEA, VEEM (manufactured by Nippon Shokubai Co., Ltd.) Etc. These can be used alone or in combination of two or more.

Sensitizers include 9-fluorenone, anthrone, dibenzosuberone, 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-fluorenecarboxaldehyde, 9-fluorenylmethanol, 2-acetylfluorene, benzophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ) Ketone, 1-hydride Xyl-cyclohexyl-phenyl-ketone, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone, 2-hydroxy Examples include -2-methyl-1- [4- (1-methylvinyl) phenyl] propanone oligomer, nitro compound, and dye. The addition amount 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. Amino group-containing silanes such as acrylic group-containing silane coupling agents, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane Examples of the coupling agent include γ-mercaptopropyltrimethoxysilane and γ-chloropropyltrimethoxysilane. 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 independently and 2 or more types may be used together.

As a polyol compound, it may be added in order to adjust the curing speed and increase the adhesive strength. Examples of the polyol compound include ethylene glycol, propylene glycol, 1,4-butanediol, 1,3-butanediol, 1,9-nonanediol, neopentyl glycol, tricyclodecane dimethylol, cyclohexane dimethylol, tri Aliphatic polyols such as methylolpropane, glycerin, hydrogenated polybutadiene polyol, hydrogenated dimer diol, diethylene glycol, tripropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, trimethylolpropane polyethoxytriol, glycerin polypropoxytriol, bisphenol Ether bonds such as A polyethoxydiol, bisphenol F polyethoxydiol, and ditrimethylolpropane One or more, with (poly) ether polyol, polyester polyol compounds, polycaprolactone polyol compound, a polyol compound having a phenolic hydroxyl group, mention may be made of polycarbonate polyol and polycarbonate diol.

<Curing method and cured product>
The present invention also provides a cured product of the above cationic curable adhesive composition for camera modules. In the case of obtaining a cured product by heat-curing the cationic curable adhesive composition of the present invention, the heating temperature is not particularly limited. For example, it is preferably a temperature of 45 ° C. or more and less than 100 ° C., more preferably 50 ° C. It is more than 95 degreeC above. Also, the heating time is not particularly limited, but for example, preferably 5 to 120 minutes, more preferably 10 to 60 minutes. Moreover, the composition which concerns on this invention can be hardened by active energy ray irradiation by containing (D) component. Examples of the active energy ray in this case include ultraviolet rays, electron beams, and visible rays, but 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. In addition, as a curing method of the cationic curable adhesive composition of the present invention, active energy ray irradiation and heating may be used in combination.

<Application>
The application of the cationic curable adhesive composition of the present invention is a camera module. The adhesion points of the camera module are between an image sensor such as CMOS and CCD and the substrate, between the cut filter and the substrate, between the substrate and the case, between the case and the cut filter, and between the case 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 excellent moldability. The cured product of the cationic curable adhesive composition of the present invention has excellent adhesion to these engineering plastics (particularly LCP). That is, other embodiment of this invention is a camera module containing the hardened | cured material of the said cationic curable adhesive composition.

<Joint>
The present invention also provides a joined body obtained by adhering two or more adherends using the above cationic curable adhesive composition for a camera module. Although it does not specifically limit as a to-be-adhered body, For example, engineering plastics, such as LCP, PPS, a polycarbonate, etc. are mentioned, Among these, LCP is preferable. Accordingly, a preferred embodiment of the present invention is a joined body obtained by adhering two or more LCPs using the above-described cationic curable adhesive composition for camera modules.

Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited by the following examples.

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

<(A) component>
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 (Celoxide 2021P, epoxy equivalent 137 g / eq, manufactured by Daicel Corporation)
<Comparison component of component (A)>
a′1: Aromatic bisphenol A type epoxy resin (jER807, manufactured by Mitsubishi Chemical Corporation)
<(B) component>
b1: Thermal cationic polymerization initiator containing a salt composed of a tetrakis (pentafluorophenyl) borate anion and a quaternary ammonium cation (CXC-1821, manufactured by King Industries)
<(C) component>
c1: Polybutadiene rubber filler having 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 filler of styrene-divinylbenzene copolymer having an average particle size of 0.6 μm (Tg 100 ° C.)
<Comparison of component (C)>
c′1: Hydroxyl-terminated polyisoprene that is liquid at 25 ° C. (Poly ip (registered trademark), manufactured by Idemitsu Kosan Co., Ltd.)
c′2: Hydroxyl group polybutadiene liquid at 25 ° C. (Poly bd (registered trademark), manufactured by Idemitsu Kosan Co., Ltd.)
c′3: Rubber filler of silicone / acrylic copolymer having an average particle diameter of 0.4 μm c′4: Urethane rubber filler having an average particle diameter of 0.3 μm c′5: Flakes-shaped acrylic resin having no rubber elasticity at 25 ° C. (ARUFON (registered trademark) UG-4035, manufactured by Toagosei 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 cationic curable adhesive composition was dropped on a hot plate set at 80 ° C., and contacted with a glass rod with a sharp tip after 30 minutes. The curability of the composition was visually observed based on the following criteria. Evaluated. If it is (circle) in the following reference | standard, it can be said that low-temperature curability is favorable. The results are shown in Table 1.

[Evaluation criteria]
○: There is no deposit on the bar. ×: There is deposit on the rod.

<Adhesiveness to engineering plastics>
A polytetrafluoroethylene tape is attached to the back of a SUS washer with a hole with a thickness of 0.5 mm and a diameter of 6.1 mm, and an LCP test piece (250 mm wide x 10 mm long x 3 mm thick) manufactured by Polyplastics Co., Ltd. VECTRA E130i). Next, each cationic curable adhesive composition was applied to the inside of the washer and cured by heating at 80 ° C. for 1 hour. Thereby, the test piece which the test piece made from LCP and the hardened | cured material of the cationic curable adhesive composition adhere | attached was obtained. And the chip | tip intensity | strength [N / mm < ² >] was measured with the push pull gauge using the said test piece. The results are shown in Table 1.

Preferred chip strength in the present invention is 6.0 N / ^{m 2} or more, more preferably 7.0 N / mm ² or more, even more preferably 8.0 N / mm ² or more, particularly preferably 10 N / it is mm ² or more (the upper limit is, for example, 20 N / mm ² or less). In Table 1, “impossible to measure” means that the test could not be performed because the cationic curable adhesive composition did not cure even when heated at 80 ° C. for 1 hour. To do.

Examples 1 to 11 show that the cationic curable adhesive composition of the present invention has both low-temperature curability (100 ° C. or lower) and adhesion to engineering plastics (LCP).

Comparative Example 1 is a composition that does not contain any of the alicyclic epoxy resin or hydrogenated epoxy resin, which is an essential component of the component (A) of the present invention, and contains only the aromatic bisphenol A type epoxy resin, but is low temperature cured. It turns out that the property is remarkably inferior. Moreover, although the comparative example 2 is a composition which does not contain the (C) component of this invention, it turns out that the adhesiveness with respect to an engineering plastic (LCP) is inferior. In Comparative Examples 3 to 5, in place of the component (C) of the present invention, a hydroxyl group-terminated polyisoprene that is liquid at 25 ° C., a hydroxyl group polybutadiene that is liquid at 25 ° C., or a silicone / acrylic copolymer having an average particle size of 0.4 μm. Although it is a composition using coalescence, it can be seen that the adhesion to engineering plastics is poor. Moreover, although the comparative example 6 is a composition which used the urethane rubber instead of (C) component of this invention, the low-temperature curability was remarkably inferior. Moreover, although the comparative example 7 is a composition using the flaky acrylic resin which is not a rubber elastic body at 25 degreeC instead of (C) component of this invention, low-temperature curability was remarkably inferior.

The present invention is a cationic curable adhesive composition having both low temperature curability and adhesion to engineering plastics (particularly LCP), and is industrially useful because it can be applied to an adhesive for camera modules.

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

(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,
(B) Component: Thermal cationic polymerization initiator, and (C) Component: Rubber filler containing at least one selected from the group consisting of diene rubbers and (meth) acrylic rubbers (excluding silicone-acrylic copolymers). Alternatively, a cationic curable adhesive composition for camera modules, comprising at least one of styrene-based fillers.
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). The cationic curable adhesive composition for camera modules described.
The cationic curing adhesive 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 cation. Composition.
The cation-curable adhesive composition for camera modules according to any one of claims 1 to 3, further comprising a photocationic polymerization initiator as the component (D).
The cationic curing 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 or an aromatic sulfonium-based photocationic polymerization initiator. Composition.
A cured product of the cationic curable adhesive composition for camera modules according to any one of claims 1 to 5.
A joined body obtained by adhering two or more adherends using the cationic curable adhesive composition for a camera module according to any one of claims 1 to 5.