Composition

Abstract

To provide a composition, whose cured product has high heat-dissipating properties and high restorability.SOLUTION: A composition contains (A) urethane methacrylate, (B) a monofunctional methacrylate other than the urethane methacrylate, (C) a polymerization initiator, (D) an inorganic filler, and (E) a thiol compound.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a composition and a cured product thereof, a resin composition, a potting material, an adhesive composition, a two-part composition, a method for bonding adherends, and a bonded body. [Background technology]

[0002] Lithium-ion secondary batteries are used in automobiles, such as electric vehicles and hybrid vehicles, and information terminals, such as personal computers and mobile devices, and demand for them is expected to continue to grow. For example, lithium-ion secondary batteries used in automobiles are composed of multiple cells stacked, connected, and packaged. Lithium-ion secondary batteries generate heat and undergo volume changes during charging and discharging. Therefore, adhesives used to bond multiple cells together and between stacked cells and heat sinks are required to have high heat dissipation and high recovery properties.

[0003] Patent Documents 1 and 2 disclose adhesives having thermal conductivity. Meanwhile, Patent Document 3 discloses an adhesive that can be cured at room temperature, has high adhesive strength, and is releasable in warm water. Patent Document 4 discloses a curable composition set that can yield a cured product with low elasticity and excellent elongation. Patent Document 5 discloses a fast-curing composition for a heat-dissipating sheet. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-188297 [Patent Document 2] International Publication No. 2014 / 136484 [Patent Document 3] Patent No. 5164316 [Patent Document 4] International Publication No. 2021 / 106992 [Patent Document 5] Japanese Patent Application Laid-Open No. 2012-188507 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a composition that provides a cured product having high heat dissipation properties and high recovery, as well as a cured product thereof, a resin composition, a potting material, an adhesive composition, a two-part composition, a method for bonding adherends, and a bonded body. [Means for solving the problem]

[0006] The present invention includes the following embodiments.

[0007] [1] (A) urethane (meth)acrylate, (B) a monofunctional (meth)acrylate other than a urethane (meth)acrylate; (C) a polymerization initiator, (D) inorganic fillers, and (E) Thiol compounds A composition comprising:

[0008] [2] The composition according to [1], wherein (A) has a weight average molecular weight of 1,000 to 500,000.

[0009] [3] The composition according to [1] or [2], wherein the content of (D) is 100 to 1500 parts by mass per 100 parts by mass of the total content of (A) and (B).

[0010] [4] The composition according to any one of [1] to [3], wherein (A) is an aliphatic urethane (meth)acrylate.

[0011] [5] The composition according to any one of [1] to [4], wherein (A) is a bifunctional urethane (meth)acrylate.

[0012] [6] The composition according to any one of [1] to [5], wherein (B) contains a monofunctional (meth)acrylate containing a polyoxypropylene group.

[0013] [7] The composition according to any one of [1] to [6], wherein (B) contains a monofunctional aromatic (meth)acrylate.

[0014] [8] The composition according to any one of [1] to [7], wherein (D) is at least one inorganic filler selected from the group consisting of alumina, aluminum hydroxide, aluminum, aluminum nitride, zinc oxide, boron nitride, silica, silicon carbide, and silicon nitride.

[0015] [9] The composition according to any one of [1] to [8], wherein (E) is a thiol compound containing two or more sulfur atoms in the molecule.

[0016]

[10] The composition according to any one of [1] to [9], further comprising (F) a plasticizer.

[0017]

[11] The composition according to

[10] , wherein (F) is an aliphatic plasticizer.

[0018]

[12] The composition according to

[10] or

[11] , wherein the content of (D) is 500 to 1500 parts by mass per 100 parts by mass of the total content of (A), (B) and (F).

[0019]

[13] The composition according to any one of

[10] to

[12] , wherein, out of 100 parts by mass of the total content of (A), (B) and (F), the content of (A) is 10 to 90 parts by mass, the content of (B) is 10 to 90 parts by mass, and the content of (F) is 0.1 to 70 parts by mass.

[0020]

[14] The composition according to any one of [1] to

[13] , further comprising (G) a bifunctional (meth)acrylate other than a urethane (meth)acrylate.

[0021]

[15] A resin composition comprising the composition according to any one of [1] to

[14] .

[0022]

[16] A curable composition comprising the composition according to any one of [1] to

[14] .

[0023]

[17] A potting material comprising the composition according to any one of [1] to

[14] .

[0024]

[18] An adhesive composition comprising the composition according to any one of [1] to

[14] .

[0025]

[19] A cured product of the composition according to any one of [1] to

[14] .

[0026]

[20] The cured product according to

[19] , which has a glass transition temperature of 25°C or lower.

[0027]

[21] The composition according to any one of [1] to

[14] , further comprising (H) a reducing agent.

[0028]

[22] A two-component composition, wherein the composition according to

[21] is divided into a first component and a second component, the first component containing at least (C) a polymerization initiator, and the second component containing at least (H) a reducing agent.

[0029]

[23] A method for bonding adherends using the adhesive composition according to

[18] .

[0030]

[24] A bonded body bonded with the curable composition according to

[16] or the adhesive composition according to

[18] . [Effects of the Invention]

[0031] According to the present invention, it is possible to provide a composition the cured product of which has high heat dissipation properties and high recovery, as well as a cured product thereof, a resin composition, a potting material, an adhesive composition, a two-part composition, a method for bonding adherends, and a bonded body. DETAILED DESCRIPTION OF THE INVENTION

[0032] [Composition] The composition according to this embodiment is preferably a resin composition, which will be described below as a representative example.

[0033] [Resin composition] The resin composition according to this embodiment contains (A) a urethane (meth)acrylate, (B) a monofunctional (meth)acrylate other than a urethane (meth)acrylate (hereinafter also referred to as "(B) monofunctional (meth)acrylate"), (C) a polymerization initiator, (D) an inorganic filler, and (E) a thiol compound.

[0034] Because the resin composition according to this embodiment contains (A) a urethane (meth)acrylate, the cured product of the resin composition experiences a large internal energy change due to entropy elasticity. When external stress is released, this energy relaxes, resulting in high resilience. Furthermore, because the resin composition according to this embodiment contains (B) a monofunctional (meth)acrylate, the cured product of the resin composition experiences a large internal energy change due to elongation-induced crystallization. When external stress is released, this energy relaxes, resulting in high resilience. Furthermore, because the resin composition according to this embodiment contains (D) an inorganic filler, the cured product of the resin composition exhibits high thermal conductivity and high heat dissipation. Furthermore, because the resin composition according to this embodiment contains (E) a thiol compound, a crosslinked structure can be formed, resulting in high resilience. Thus, the cured product of the resin composition according to this embodiment has high heat dissipation and high recovery, so that when the resin composition according to this embodiment is used, for example, to bond multiple cells together or to bond multiple stacked cells to a heat sink, the high heat dissipation properties allow the cells to be sufficiently cooled, and the high recovery properties allow it to adequately accommodate changes in cell volume caused by charging and discharging, thereby maintaining adhesion. The curable composition set disclosed in Patent Document 4 and the composition for heat dissipation sheets disclosed in Patent Document 5 differ from the resin composition according to this embodiment in that they do not contain a combination of a urethane (meth)acrylate and a thiol compound.

[0035] The resin composition according to the present embodiment contains at least (A) a urethane (meth)acrylate, (B) a monofunctional (meth)acrylate, (C) a polymerization initiator, (D) an inorganic filler, and (E) a thiol compound, but may also contain other components, such as (F) a plasticizer, (G) a bifunctional (meth)acrylate other than the urethane (meth)acrylate (hereinafter also referred to as "(G) bifunctional (meth)acrylate"), (H) a reducing agent, etc.

[0036] ((A) Urethane (meth)acrylate) The urethane (meth)acrylate (A) according to this embodiment is not particularly limited, but is preferably an aliphatic urethane (meth)acrylate from the viewpoint of further improving recovery. Examples of the aliphatic moiety of the aliphatic urethane (meth)acrylate include polyethers obtained by addition polymerization of dihydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, and hexamethylene glycol; polyesters formed by polycondensation of alcohols such as dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, and neopentyl glycol with dibasic acids such as adipic acid, azelaic acid, and sebacic acid; polydiene polyols having hydroxyl groups at both ends of the molecule, such as polybutadiene, butadiene-acrylonitrile copolymer, and polyisoprene; and polyolefin polyols having hydroxyl groups at both ends of the molecule, such as hydrogenated polybutadiene, hydrogenated polyisoprene, and polyisobutylene. Commercially available aliphatic urethane (meth)acrylates include, for example, UV-3700B, UV-3300B, and UV-6640B (all trade names) manufactured by Mitsubishi Chemical Corporation, EBECRYL series 8402, 8804, and 9270 (all trade names) manufactured by Daicel Allnex Co., Ltd., CN series 996, 980, and 9893 (all trade names) manufactured by Sartomer, and UN-6200, UN-6202, and UN-6305 (all trade names) manufactured by Negami Chemical Industrial Co., Ltd. Furthermore, aromatic urethane (meth)acrylates can also be used as the (A) urethane (meth)acrylate. Commercially available aromatic urethane (meth)acrylates include, for example, EBECRY210 (trade name) manufactured by Daicel Allnex Corporation, CN978, CN9782, and CN9783 (trade names) manufactured by Sartomer Corporation, and UN9000PEP and UN-9200A (trade names) manufactured by Negami Chemical Industrial Co., Ltd. These (A) urethane (meth)acrylates may be used alone or in combination of two or more. From the viewpoint of forming a crosslinked structure, the (A) urethane (meth)acrylate is preferably a bifunctional urethane (meth)acrylate.

[0037] The weight-average molecular weight of (A) urethane (meth)acrylate is preferably 1,000 to 500,000. A weight-average molecular weight of 1,000 or more provides flexibility and higher recovery. A weight-average molecular weight of 500,000 or less provides excellent curing properties and workability. The weight-average molecular weight is more preferably 5,000 to 250,000, and even more preferably 10,000 to 100,000. The weight-average molecular weight (Mw) of (A) urethane (meth)acrylate is a value measured by gel permeation chromatography (GPC) using polystyrene as a standard substance.

[0038] The amount of (A) urethane (meth)acrylate contained in 100% by mass of the resin composition according to this embodiment is preferably 5 to 50% by mass, more preferably 10 to 30% by mass, and even more preferably 10 to 20% by mass, from the viewpoint of higher heat dissipation and recovery properties.

[0039] ((B) Monofunctional (meth)acrylate) The (B) monofunctional (meth)acrylate according to this embodiment is a monofunctional (meth)acrylate other than urethane (meth)acrylate and does not include the (A) urethane (meth)acrylate. The (B) monofunctional (meth)acrylate is not particularly limited, but from the viewpoint of further improving recovery at high temperatures, it is preferable to include a monofunctional (meth)acrylate containing a polyoxypropylene group. Examples of monofunctional (meth)acrylates containing a polyoxypropylene group include polypropylene glycol (meth)acrylate, methoxydipropylene glycol (meth)acrylate, nonylphenoxy polypropylene glycol (meth)acrylate, and nonylphenoxy polypropylene glycol (meth)acrylate. The (B) monofunctional (meth)acrylate may contain one or more of these. In this embodiment, "(meth)acrylate" refers to acrylate and methacrylate.

[0040] Furthermore, from the viewpoint of further improving recovery and adhesiveness, (B) monofunctional (meth)acrylate preferably contains a monofunctional aromatic (meth)acrylate. Examples of monofunctional aromatic (meth)acrylates include phenoxy polyethylene glycol (meth)acrylate, phenoxy diethylene glycol (meth)acrylate, phenoxy benzyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, phenoxy ethyl (meth)acrylate, methylphenoxy ethyl (meth)acrylate, and nonylphenoxy polyethylene glycol (meth)acrylate. The monofunctional aromatic (meth)acrylate preferably excludes the monofunctional (meth)acrylate containing a polyoxypropylene group. (B) monofunctional (meth)acrylate may contain one or more of these. In particular, (B) monofunctional (meth)acrylate preferably contains both the monofunctional (meth)acrylate containing a polyoxypropylene group and the monofunctional aromatic (meth)acrylate. When both the monofunctional (meth)acrylate containing a polyoxypropylene group and the monofunctional aromatic (meth)acrylate are contained, the mixing ratio of the monofunctional (meth)acrylate containing a polyoxypropylene group to the monofunctional aromatic (meth)acrylate is preferably 25 to 75:25 to 75 (mass ratio), more preferably 40 to 60:40 to 60 (mass ratio), per 100 parts by mass of the total of the monofunctional (meth)acrylate containing a polyoxypropylene group and the monofunctional aromatic (meth)acrylate.

[0041] The amount of (B) monofunctional (meth)acrylate contained in 100% by mass of the resin composition according to this embodiment is preferably 1 to 50% by mass, more preferably 3 to 30% by mass, and even more preferably 5 to 20% by mass, from the viewpoint of higher heat dissipation and recovery properties.

[0042] ((C) Polymerization initiator) The resin composition according to this embodiment includes a polymerization initiator (C). The polymerization initiator (C) is preferably a radical polymerization initiator. The radical polymerization initiator is preferably a thermal radical polymerization initiator. The thermal radical polymerization initiator is preferably an organic peroxide. The organic peroxide is not particularly limited, but examples thereof include cumene hydroperoxide, dibenzoyl peroxide, cycloalkane hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, and bis-(4-tetrabutylcyclohexyl) peroxide carbonate. These may be used alone or in combination of two or more.

[0043] The amount of (C) polymerization initiator contained in 100% by mass of the resin composition according to this embodiment is preferably 0.1 to 5% by mass, more preferably 0.3 to 3% by mass, and even more preferably 0.5 to 2% by mass, from the viewpoints of curability, storage stability, and adhesion.

[0044] When the resin composition according to the present embodiment contains a plasticizer (F), the amount of the polymerization initiator (C) is preferably 1 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, and even more preferably 1 to 8 parts by mass, per 100 parts by mass of the total content of the urethane (meth)acrylate (A), the monofunctional (meth)acrylate (B), and the plasticizer (F), from the viewpoints of curability, storage stability, and adhesion.

[0045] ((D) Inorganic filler) The inorganic filler (D) according to this embodiment is not particularly limited, but from the viewpoint of further improving thermal conductivity, it is preferably at least one inorganic filler selected from the group consisting of alumina, aluminum hydroxide, aluminum, aluminum nitride, zinc oxide, boron nitride, silica, silicon carbide, and silicon nitride. The shape of the inorganic filler (D) is not particularly limited, and may be spherical, scaly, or the like. In addition, the inorganic filler (D) may be aggregated into a mass.

[0046] (D) The insulating properties of inorganic fillers are as follows: volume resistivity is 10 8 It is preferable that the resistance is 10 Ωm or more. 10(D) The insulating property of the inorganic filler is preferably such that the volume resistivity is 10 17 The volume resistivity refers to the volume resistivity at 20°C measured in accordance with JIS C 2141.

[0047] The insulating properties of the (D) inorganic filler are preferably such that the breakdown voltage is 5 kV / mm or more, more preferably 10 kV / mm or more. The insulating properties of the (D) inorganic filler can be such that the breakdown voltage is 20 kV / mm or less. The breakdown voltage refers to the strength of the dielectric breakdown at 20°C measured in accordance with JIS C 2110.

[0048] The average particle diameter of the (D) inorganic filler is preferably 0.1 to 100 μm, and more preferably 0.2 to 60 μm. When the average particle diameter is 0.1 μm or more, the content of the (D) inorganic filler can be increased. Furthermore, when the cured resin composition is formed into a sheet, the thickness of the sheet can be reduced when the average particle diameter is 100 μm or less. The average particle diameter of the (D) inorganic filler can be measured, for example, using a laser diffraction / scattering particle size distribution analyzer manufactured by Beckman Coulter (product name: LS-13 320). The average particle diameter of the (D) inorganic filler can be measured without using a homogenizer before the measurement process. Therefore, when the (D) inorganic filler is an agglomerated particle, the average particle diameter of the (D) inorganic filler is the average particle diameter of the agglomerated particle. The obtained average particle diameter is, for example, an average particle diameter determined by volume statistics. It is also preferable to mix two or more types of (D) inorganic fillers with different average particle sizes, since this allows closest packing, allows more filler to be packed, and prevents an increase in viscosity.

[0049] The (D) inorganic filler used in this embodiment is preferably a combination of three types of inorganic fillers: (Da) inorganic filler having an average particle size of 0.1 μm or more and less than 2 μm, (Db) inorganic filler having an average particle size of 2 μm or more and less than 20 μm, and (Dc) inorganic filler having an average particle size of 20 μm or more and 100 μm or less.

[0050] From the viewpoints of high workability, fast curing, high thermal conductivity, and low outgassing, the average particle size of component (Da) is preferably 0.1 μm or more but less than 2 μm, more preferably 0.2 μm or more but less than 1 μm, and most preferably 0.3 μm or more but less than 0.8 μm. From the viewpoints of high workability, fast curing, high thermal conductivity, and low outgassing, the average particle size of component (Db) is preferably 2 μm or more but less than 20 μm, more preferably 2 μm or more but less than 10 μm, and most preferably 3.5 μm or more but less than 8 μm. From the viewpoints of high workability, fast curing, high thermal conductivity, and low outgassing, the average particle size of component (Dc) is preferably 20 μm or more but less than 100 μm, more preferably 30 μm or more but less than 80 μm, and most preferably 35 μm or more but less than 60 μm.

[0051] The mixing ratios of the three (D) components are preferably 1 to 50% by mass of the (Da), (Db), and (Dc) components, 3 to 80% by mass of the (Da), (Db), and (Dc) components, and 15 to 95% by mass of the (Da), (Db), and (Dc) components combined. Of the total 100% by mass of the (Da), (Db), and (Dc), the (Da), (Db), and (Dc) components are preferably 3 to 40% by mass of the (Da), (Db), and (Dc) components, 10 to 40% by mass of the (Db), and (Dc) components, and 50 to 85% by mass of the (Da), (Db), and (Dc) components are preferably 1 to 9% by mass of the (Da), (Db), and (Dc) components, 15 to 24% by mass of the (Dc), and 61 to 80% by mass of the (Da), (Db), and (Dc) components combined. The mixing ratios (% by mass) of the (Da), (Db), and (Dc) components in the (A) component preferably satisfy the relationship (Da)<(Db)<(Dc).

[0052] The content of (D) inorganic filler is preferably 100 to 1500 parts by mass per 100 parts by mass of the total content of (A) urethane (meth)acrylate and (B) monofunctional (meth)acrylate. Having this content of 100 parts by mass or more provides better heat dissipation properties. Furthermore, having this content of 1500 parts by mass or less provides better recovery and excellent workability. The content is more preferably 200 to 1000 parts by mass, and even more preferably 250 to 750 parts by mass.

[0053] The amount of (D) inorganic filler contained in 100% by mass of the resin composition according to this embodiment is preferably 50 to 95% by mass, more preferably 65 to 90% by mass, and even more preferably 70 to 85% by mass, from the viewpoint of higher heat dissipation and recovery properties.

[0054] ((E) Thiol Compounds) The thiol compound (E) according to this embodiment is not particularly limited, but is preferably a thiol compound containing two or more sulfur atoms in the molecule from the viewpoint of obtaining higher restorability. Examples of thiol compounds containing two or more sulfur atoms in the molecule include pentaerythritol tetrakis(3-mercaptobutyrate), pentaerythritol tetrakis(3-mercaptopropionate), 1,4-bis(3-mercaptobutyloxy)butane, 1,3,5-tris(3-mercaptobutyryloxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, trimethylolpropane tris(3-mercaptobutyrate), trimethylolpropane tris(3-mercaptopropionate), tris-[(3-mercaptopropionyloxy)-ethyl]-isocyanurate, and tetraethylene glycol bis(3-mercaptopropionate). These may be used alone or in combination of two or more. The thiol compound (E) is more preferably a thiol compound containing three or more sulfur atoms in the molecule, and even more preferably a thiol compound containing four or more sulfur atoms in the molecule.

[0055] The amount of the (E) thiol compound contained in 100% by mass of the resin composition according to this embodiment is preferably 0.01 to 3% by mass, more preferably 0.02 to 2% by mass, and even more preferably 0.1 to 1% by mass, from the viewpoint of higher heat dissipation and recovery properties.

[0056] When the resin composition according to the present embodiment contains a (F) plasticizer, the amount of the (E) thiol compound is, from the viewpoint of higher heat dissipation and recovery properties, preferably 0.1 to 10 parts by mass, more preferably 0.5 to 8 parts by mass, and even more preferably 0.8 to 5 parts by mass, per 100 parts by mass of the total content of the (A) urethane (meth)acrylate, the (B) monofunctional (meth)acrylate, and the (F) plasticizer.

[0057] ((F) Plasticizer) The resin composition according to this embodiment preferably further contains a (F) plasticizer, from the viewpoint of improving the resistance to breakage and increasing the extensibility of the cured product. While the (F) plasticizer is not particularly limited, an aliphatic plasticizer is preferred, from the viewpoint of improving the resistance to breakage and increasing the extensibility of the cured product. Examples of aliphatic plasticizers include dicarboxylic acid diesters such as dioctyl sebacate, bis(2-ethylhexyl) sebacate, bis(2-ethylhexyl) adipate, diisononyl adipate, diisodecyl adipate, bis(2-ethylhexyl) azelate, bis(2-ethylhexyl) 4-cyclohexene-1,2-dicarboxylate, and diisononyl phthalate. These may be used alone or in combination of two or more. Dicarboxylic acid diesters are particularly preferred as the (F) plasticizer.

[0058] When the resin composition according to this embodiment contains a plasticizer (F), it is preferable that the content of the urethane (meth)acrylate (A), the monofunctional (meth)acrylate (B), and the plasticizer (F) is 10 to 90 parts by mass, the content of the monofunctional (meth)acrylate (B), and the content of the plasticizer (F) be 10 to 90 parts by mass, and 0.1 to 70 parts by mass, respectively, out of a total of 100 parts by mass of the urethane (meth)acrylate (A), the monofunctional (meth)acrylate (B), and the plasticizer (F). By keeping the contents of these components within the above ranges, it is possible to obtain better flexibility and high recovery. It is more preferable that the content of (A) urethane (meth)acrylate is 20 to 80 parts by mass, the content of (B) monofunctional (meth)acrylate is 15 to 60 parts by mass, and the content of (F) plasticizer is 10 to 60 parts by mass, and it is even more preferable that the content of (A) urethane (meth)acrylate is 25 to 55 parts by mass, the content of (B) monofunctional (meth)acrylate is 20 to 40 parts by mass, and the content of (F) plasticizer is 15 to 50 parts by mass.

[0059] When the resin composition according to this embodiment contains a (F) plasticizer, the content of the (D) inorganic filler is preferably 500 to 1,500 parts by mass per 100 parts by mass of the total content of the (A) urethane (meth)acrylate, the (B) monofunctional (meth)acrylate, and the (F) plasticizer. A content of 500 parts by mass or more provides improved heat dissipation. Furthermore, a content of 1,500 parts by mass or less provides improved recovery and excellent workability. The content is more preferably 200 to 1,000 parts by mass, and even more preferably 250 to 750 parts by mass.

[0060] When the resin composition according to this embodiment contains a plasticizer (F), the amount of the plasticizer (F) contained in 100% by mass of the resin composition according to this embodiment is preferably 1 to 50% by mass, more preferably 3 to 40% by mass, and even more preferably 5 to 20% by mass, from the viewpoint of suppressing breakage and improving the extensibility of the cured product.

[0061] When the resin composition according to the present embodiment contains a (F) plasticizer, the amount of the (F) plasticizer is, from the viewpoint of suppressing breakage and improving the extensibility of the cured product, preferably 5 to 60 parts by mass, more preferably 15 to 40 parts by mass, and even more preferably 20 to 30 parts by mass, relative to 100 parts by mass of the total content of the (A) urethane (meth)acrylate, the (B) monofunctional (meth)acrylate, and the (F) plasticizer.

[0062] ((G) Difunctional (meth)acrylate) The resin composition according to this embodiment preferably further contains a (G) difunctional (meth)acrylate, from the viewpoint of being more likely to form a crosslinked structure and exhibiting higher restoring properties in a cured product of the resin composition. The (G) difunctional (meth)acrylate is not a urethane (meth)acrylate, and therefore does not contain an (A) urethane (meth)acrylate. The (G) difunctional (meth)acrylate is not particularly limited, but examples thereof include difunctional 2-hydroxyethyl (meth)acrylate acid phosphate, triethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, and dimethylol-tricyclodecane di(meth)acrylate. These may be used alone or in combination of two or more.

[0063] When the resin composition according to this embodiment contains a (G) bifunctional (meth)acrylate, the amount of the (G) bifunctional (meth)acrylate contained in 100% by mass of the resin composition according to this embodiment is preferably 0.01 to 10% by mass, more preferably 0.1 to 5% by mass, and even more preferably 0.3 to 3% by mass, from the viewpoint of improving recovery properties, etc.

[0064] When the resin composition according to the present embodiment contains a (G) bifunctional (meth)acrylate, the amount of the (G) bifunctional (meth)acrylate is, from the viewpoint of improving recovery, etc., preferably 0.1 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, and even more preferably 1 to 8 parts by mass, relative to 100 parts by mass of the total content of the (A) urethane (meth)acrylate, the (B) monofunctional (meth)acrylate, and the (F) plasticizer.

[0065] ((H) Reducing Agent) The resin composition according to this embodiment may contain a reducing agent (H) from the viewpoint of curability. The reducing agent (H) is preferably a reducing agent that reacts with the polymerization initiator (C), preferably an organic peroxide, to generate radicals. Examples of the reducing agent (H) include vanadyl acetylacetonate, acetylacetone vanadyl, 2-ethylhexyl cobalt, tris(2,4-pentanedionato)cobalt, 1-acetyl-2-thiourea, acetylthiourea, and trimethylthiourea. These may be used alone or in combination of two or more.

[0066] When the resin composition according to the present embodiment contains a (F) plasticizer, the amount of the (H) reducing agent is, from the viewpoints of curability, storage stability, and adhesion, preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, and even more preferably 0.1 to 1 part by mass, per 100 parts by mass of the total content of the (A) urethane (meth)acrylate, the (B) monofunctional (meth)acrylate, and the (F) plasticizer.

[0067] (Other ingredients) The resin composition according to the present embodiment may contain other components, such as an antioxidant and an epoxy resin, in addition to the components described above.

[0068] (Application) The resin composition according to this embodiment has curability and adhesive properties, as well as high heat dissipation and recovery properties, and therefore can be used, for example, as a potting material used in electrical and electronic components, an adhesive for secondary battery cells, and an adhesive for heat dissipation to dissipate heat from a substrate (typically a heat sink, etc.).

[0069] [Curable compositions, potting materials, adhesive compositions] The curable composition according to this embodiment is composed of the composition according to this embodiment. The composition according to this embodiment is curable because the polymerization initiator (C) causes polymerization and crosslinking of the urethane (meth)acrylate (A), the monofunctional (meth)acrylate (B), and the thiol compound (E). During curing, the aforementioned reducing agent (H) may be used in combination with the polymerization initiator (C).

[0070] The potting material according to this embodiment is made of the composition according to this embodiment. By curing the composition according to this embodiment, it can be used, for example, as a potting material for electric and electronic components. Furthermore, the adhesive composition according to this embodiment is made of the composition according to this embodiment. By curing the composition according to this embodiment, it can be used, for example, as a heat dissipation adhesive for releasing heat from a cell of a secondary battery or a substrate (generally a heat sink, etc.).

[0071] [Cured product] The cured product according to this embodiment is a cured product of the composition according to this embodiment. The glass transition temperature of the cured product is preferably 25°C or lower from the viewpoint of constantly releasing heat in response to changes in the volume of various substrates. The glass transition temperature is more preferably 10°C or lower, even more preferably 0°C or lower, and particularly preferably -10°C or lower. The lower limit of the range of the glass transition temperature is not particularly limited, but can be, for example, -60°C or higher. The glass transition temperature is a value measured by the method described below.

[0072] From the viewpoint of heat dissipation, the thermal conductivity of the cured product according to this embodiment is preferably 0.5 mW / m K or more, more preferably 0.7 mW / m K or more, and even more preferably 1.0 mW / m K or more. The thermal conductivity is a value measured by the method described below.

[0073] From the viewpoint of restorability, the inter-grade distance after 30% deformation of the cured product according to this embodiment (initial inter-grade distance: 10.0 mm) is preferably 11.0 mm or less, more preferably 10.5 mm or less, and even more preferably 10.1 mm or less. The inter-grade distance after 30% deformation is a value measured by the method described below.

[0074] The breaking elongation of the cured product according to the present embodiment is preferably 30% or more, more preferably 50% or more, and even more preferably 100% or more, from the viewpoint of constantly releasing heat in response to changes in the volume of various substrates. The breaking elongation is a value measured by the method described below.

[0075] The breaking shear strength of the cured product according to this embodiment is preferably 0.3 MPa or more, more preferably 0.5 MPa or more, and even more preferably 1.0 MPa or more, from the viewpoint of constantly releasing heat in response to changes in the volume of various substrates. The breaking shear strength is a value measured by the method described below.

[0076] [Two-dose composition] The two-component composition according to this embodiment is preferably a two-component composition in which the composition according to this embodiment is divided into a first component and a second component, the first component containing at least a polymerization initiator (C), and the second component containing at least a reducing agent (H). That is, the two-component composition according to this embodiment preferably comprises a first component containing at least a polymerization initiator (C) and a second component containing at least a reducing agent (H), and the mixture of the first and second components is the composition (cured product) according to this embodiment. By mixing the first component containing a polymerization initiator (C) with the second component containing a reducing agent (H), the reducing agent (H) promotes decomposition of the polymerization initiator (C), preferably an organic peroxide, to form a cured product. This cured product can be used in the same applications as the cured product of the composition according to this embodiment. The mixing ratio of the first agent to the second agent is preferably 25 to 75:25 to 75 (mass ratio), more preferably 40 to 60:40 to 60 (mass ratio), and even more preferably 50:50 (mass ratio), based on a total of 100 parts by mass of the first agent and the second agent. The thiol compound (E) is preferably contained in the first agent.

[0077] The amount of (H) reducing agent contained in the second agent is preferably 0.1 to 50 parts by mass, and more preferably 1 to 20 parts by mass, per 100 parts by mass of (C) polymerization initiator contained in the first agent. In addition to (H) reducing agent, the second agent may also contain, for example, an antioxidant.

[0078] [Method for bonding adherends, bonded bodies] The method for bonding adherends according to this embodiment uses the adhesive composition according to this embodiment to bond the adherends. In this method, for example, the adhesive composition according to this embodiment is applied to the bonding surface of the adherend, and the adhesive composition is cured by, for example, holding it at room temperature for about an hour, thereby bonding the adherends. Examples of the adherend include substrates such as cells of secondary batteries and heat sinks. The bonded body according to this embodiment is a bonded body bonded with the curable composition according to this embodiment or the adhesive composition according to this embodiment, and examples thereof include adherends bonded by the above-described method. [Example]

[0079] The following examples are provided to further illustrate the present invention, but are not intended to limit the scope of the present invention. The glass transition temperature (Tg), elongation at break, inter-rater distance after 30% deformation, thermal conductivity, and tensile shear strength of the cured resin compositions obtained in each example and comparative example were measured by the following methods.

[0080] [Glass transition temperature (Tg)] A cured resin composition measuring 6 mm in width, 20 mm in length, and 1 mm in thickness was measured using a viscoelasticity measuring device (trade name: DMS7100, manufactured by Hitachi High-Tech Science Corporation) starting from -60°C to 200°C at a frequency of 1 Hz and a heating rate of 2°C / min, and the peak of tan δ of the obtained data was taken as the glass transition temperature.

[0081] [Elongation at break] The cured resin composition was cut into a dumbbell-shaped 1B-A test piece and subjected to a tensile test in accordance with ISO 527 to measure the breaking elongation at a temperature of 23°C and a crosshead speed (tensile speed) of 50 mm / min.

[0082] [30% deformation distance between ratings] The cured resin composition was cut into a dumbbell-shaped 1B-A test piece and subjected to a tensile test in accordance with ISO 527. The test was conducted at a temperature of 23°C and a crosshead speed (tensile speed) of 50 mm / min, and the test was stopped when the distance between the marks reached 30% (initial distance between marks: 10.0 mm). The distance between the marks was then measured with a vernier caliper and recorded as the distance between the marks after 30% deformation.

[0083] [Thermal Conductivity] The thermal conductivity of a cured resin composition measuring 10 mm in width and length and 1 mm in thickness was measured in an atmosphere of 25°C using a xenon flash (LF447 (trade name) manufactured by NETZSCH).

[0084] [Tensile shear strength] Two aluminum test pieces (A5052P) measuring 25 mm wide, 100 mm long, and 2 mm thick were bonded together using a test piece made of a cured resin composition with an area of ​​25 mm wide and 12.5 mm long, with 0.1 mm thick spherical beads added to make the adhesive thickness 0.1 mm. Using this sample, the tensile shear strength was measured at a crosshead speed (tensile speed) of 10 mm / min in an atmosphere of 23°C.

[0085] [Examples 1 to 12, Comparative Examples 1 to 5] A resin composition was prepared by mixing the components shown in Tables 1 and 2 in the amounts shown in Tables 1 and 2. The first and second components were mixed in equal amounts by mass. The resin composition was cured by aging for 24 hours in an atmosphere at a temperature of 23°C and a humidity of 50%, yielding a cured product. The glass transition temperature (Tg), elongation at break, inter-rater distance after 30% deformation, thermal conductivity, and tensile shear strength of the cured product were measured using the methods described above. The results are shown in Tables 1 and 2. Details of each component shown in Tables 1 and 2 are as follows:

[0086] <(A) Urethane (meth)acrylate> (A-1) Difunctional aliphatic urethane acrylate (trade name: UV-3700B, manufactured by Mitsubishi Chemical Corporation, weight average molecular weight: 38,000) (A-2) Difunctional aliphatic urethane acrylate (trade name: UV-3300, manufactured by Mitsubishi Chemical Corporation, weight average molecular weight: 13,000)

[0087] <(B) Monofunctional (meth)acrylate> (B-1) Phenoxy polyethylene glycol acrylate (trade name: AMP-60G, manufactured by Shin-Nakamura Chemical Co., Ltd.) (B-2) 2-Hydroxy-3-phenoxypropyl acrylate (trade name: M-600A, manufactured by Kyoeisha Chemical Co., Ltd.) (B-3) Phenoxyethyl acrylate (trade name: PO-A, manufactured by Kyoeisha Chemical Co., Ltd.) (B-4) Phenoxyethyl methacrylate (trade name: PO, manufactured by Kyoeisha Chemical Co., Ltd.) (B-5) Polypropylene glycol acrylate (trade name: AP-400, manufactured by NOF Corporation) (B-6) n-Butyl acrylate (trade name: BA, manufactured by Tokyo Chemical Industry Co., Ltd.) (B-7) Isostearyl acrylate (trade name: ISTA, manufactured by Osaka Organic Chemical Industry Co., Ltd.) (B-8) Methoxypolyethylene glycol acrylate (trade name: AM-90G, manufactured by Shin-Nakamura Chemical Co., Ltd.) (B-9) 2-Hydroxyethyl methacrylate (trade name: 2HEMA, manufactured by Mitsubishi Chemical Corporation) (B-10) Ethylhexyl methacrylate (trade name: EHMA, manufactured by Mitsubishi Gas Chemical Co., Ltd.) (B-11) 2-Hydroxypropyl methacrylate (trade name: HPMA, manufactured by MION) (B-12) Dicyclopentenyloxyethyl methacrylate (trade name: FA-512M, manufactured by Showa Denko Materials Co., Ltd.)

[0088] <(G) Difunctional (meth)acrylate> (G-1) 2-Hydroxyethyl methacrylate acid phosphate (trade name: JPA-514, manufactured by Johoku Chemical Industry Co., Ltd., monofunctional:bifunctional=1:1 mixture) (G-2) PEG400# diacrylate (trade name: 9EG-A, manufactured by Kyoeisha Chemical Co., Ltd.) (G-3) 1,9-nonanediol diacrylate (trade name: 1,9-NDA, manufactured by Kyoeisha Chemical Co., Ltd.)

[0089] <(C) Polymerization initiator> (C-1) Cumene hydroperoxide (trade name: PH-80, manufactured by NOF Corporation)

[0090] <(H) Reducing Agent> (H-1) Vanadyl acetylacetonate (trade name: Vo(Ac)2, manufactured by Shinko Chemical Industry Co., Ltd.)

[0091] <(D) Inorganic filler> (D-1) Alumina (trade name: DAW-45S, manufactured by Denka Co., Ltd., average particle size: 45 μm) (D-2) Alumina (trade name: DAW-05, manufactured by Denka Co., Ltd., average particle size: 5 μm) (D-3) Alumina (trade name: ASFP-40, manufactured by Denka Co., Ltd., average particle size: 0.4 μm) (D-4) Aluminum hydroxide (trade name: CW-350B, manufactured by Sumitomo Chemical Co., Ltd., average particle size: 51 μm) (D-5) Aluminum hydroxide (trade name: CL-303, manufactured by Sumitomo Chemical Co., Ltd., average particle size: 4 μm) The volume resistivity of (D-1), (D-2) and (D-3) is 10 14~15 Ω / cm and the breakdown voltage is 10 to 15 kV / mm.

[0092] <(E) Thiol Compound> (E-1) Pentaerythritol tetrakis(3-mercaptobutyrate) (trade name: MT-PE1, manufactured by Showa Denko K.K.)

[0093] <(F) Plasticizer> (F-1) Dioctyl sebacate (trade name: DOS, manufactured by Daihachi Chemical Industry Co., Ltd.)

[0094] [Table 1]

[0095] [Table 2]

[0096] As shown in Tables 1 and 2, the cured products of the resin compositions of Examples 1 to 12 according to this embodiment had a rating line distance of 11.0 mm or less after 30% deformation, indicating high recovery. Furthermore, the cured products had a thermal conductivity of 0.5 mW / m K or more, indicating high heat dissipation.

[0097] On the other hand, the resin compositions of Comparative Examples 1 and 4 did not contain component (E), and therefore had low elongations at break of 10% and 15%, respectively. Therefore, when measuring the distance between the rating points after 30% deformation, the cured product broke during 30% deformation, making it impossible to perform the measurement. Furthermore, in Comparative Example 2, the resin composition did not contain component (A), so the resin composition did not cure, and each evaluation could not be performed. Furthermore, in Comparative Example 3, the resin composition did not contain component (D), so it was found that the thermal conductivity was low and heat dissipation was poor. Furthermore, in Comparative Example 5, the resin composition did not contain component (E), so the distance between the rating points after 30% deformation exceeded 20.0 mm, indicating poor recovery.

Claims

1. (A) urethane (meth)acrylate, (B) a monofunctional (meth)acrylate other than a urethane (meth)acrylate; (C) a polymerization initiator, (D) an inorganic filler, and (E) Thiol compound A composition comprising: The content of (D) is 100 to 1500 parts by mass per 100 parts by mass of the total content of (A) and (B), A composition wherein (A) is an aliphatic urethane (meth)acrylate.

2. 2. The composition according to claim 1, wherein the weight average molecular weight of (A) is 1,000 to 500,000.

3. The composition according to claim 1 or 2, wherein (A) is a difunctional urethane (meth)acrylate.

4. The composition according to any one of claims 1 to 3, wherein (B) comprises a monofunctional (meth)acrylate containing a polyoxypropylene group.

5. The composition according to any one of claims 1 to 4, wherein (B) comprises a monofunctional aromatic (meth)acrylate.

6. The composition according to any one of claims 1 to 5, wherein (D) is at least one inorganic filler selected from the group consisting of alumina, aluminum hydroxide, aluminum, aluminum nitride, zinc oxide, boron nitride, silica, silicon carbide, and silicon nitride.

7. The composition according to any one of claims 1 to 6, wherein (E) is a thiol compound containing two or more sulfur atoms in the molecule.

8. The composition according to any one of claims 1 to 7, further comprising (F) a plasticizer.

9. The composition of claim 8, wherein (F) is an aliphatic plasticizer.

10. The composition according to claim 8 or 9, wherein the content of (D) is 500 to 1500 parts by mass per 100 parts by mass of the total content of (A), (B), and (F).

11. The composition according to any one of claims 8 to 10, wherein, based on 100 parts by mass of the total content of (A), (B), and (F), the content of (A) is 10 to 90 parts by mass, the content of (B) is 10 to 90 parts by mass, and the content of (F) is 0.1 to 70 parts by mass.

12. The composition according to any one of claims 1 to 11, further comprising (G) a difunctional (meth)acrylate other than a urethane (meth)acrylate.

13. A resin composition comprising the composition according to any one of claims 1 to 12.

14. A curable composition comprising the composition according to any one of claims 1 to 12.

15. A potting material comprising the composition according to any one of claims 1 to 12.

16. An adhesive composition comprising the composition according to any one of claims 1 to 12.

17. A cured product of the composition according to any one of claims 1 to 12.

18. The cured product according to claim 17, having a glass transition temperature of 25°C or lower.

19. The composition according to any one of claims 1 to 12, further comprising (H) a reducing agent.

20. 20. A two-part composition, wherein the composition according to claim 19 is divided into a first part and a second part, the first part containing at least (C) a polymerization initiator, and the second part containing at least (H) a reducing agent.

21. A method for bonding adherends using the adhesive composition according to claim 16.

22. A bonded article bonded with the curable composition according to claim 14 or the adhesive composition according to claim 16.

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