Curable composition and heat conductive member

Abstract

Provided is a curable composition containing an epoxy resin, a thermally conductive filler, an amine compound (X) containing two or more amino groups, and a polyfunctional acrylate compound. The amine compound (X) has a viscosity of 20 Pa.s or less at 25 DEG C and 10 rpm as measured by an E-type viscometer, or has an oxyalkylene structure. The content of the amine compound (X) is from 15% by mass to 55% by mass (inclusive) with respect to the total resin component.

Description

Technical Field

[0001] The present invention relates to a curable composition and a thermally conductive component used in electronic devices such as battery modules. Background Art

[0002] Thermally conductive compositions, for example, are filled between a heating element and a heat sink to conduct heat generated by the heating element and dissipate it from the heat sink. Thermally conductive compositions are typically composed of curable curable compositions, which are often cured after filling and used as a cured product. Curable compositions play an important role in many electronic applications, including battery components such as lithium-ion battery (LiB) components used in electric vehicles (EVs), power electronics, electronic packaging, LEDs, solar cells, and power grids.

[0003] For example, Patent Document 1 discloses a curable composition comprising an epoxy resin, a polyamide composition comprising an amine-terminated polyamide containing a tertiary amide in the main chain, an amino-functional compound containing 2 to 20 carbon atoms, a polyfunctional (meth)acrylate, and an inorganic filler. The composition is suitable for use in electronic devices such as battery components.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2021-512990 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] However, as the number of EVs produced increases, productivity needs to be improved. For example, to shorten the time required for battery assembly, curable compositions must have a moderately low compressive load and be able to maintain this low compressive load for a long time, thereby extending their usable life. Furthermore, when dispensing the curable composition using a dispenser, for example, the viscosity needs to be reduced for ease of use. Furthermore, rapid curing at room temperature after assembly is required; specifically, rapid curing with sufficient adhesion to allow for temporary bonding is required, requiring a short curing time.

[0009] The curable composition disclosed in Patent Document 1 is claimed to exhibit sufficient green strength after curing at room temperature for approximately 10 minutes or less, and is therefore believed to have sufficiently rapid curing properties. However, the curable composition of Patent Document 1 contains a large amount of polyamide and a small amount of amine compound. Consequently, the viscosity before curing increases due to interaction with the polyamide, and it is difficult to extend the pot life.

[0010] Therefore, an object of the present invention is to provide a curable composition that has low viscosity, fast curing properties, and a prolonged pot life.

[0011] Means of solving the problem

[0012] The present inventors have conducted intensive research and have discovered that the above-mentioned problems can be solved by using a specific amine compound (X) in a specific amount or by adding a specific amount of water to a curable composition comprising an epoxy resin, a thermally conductive filler, an amine compound (X) containing two or more amino groups, and a polyfunctional acrylate compound. This has led to the completion of the following invention. Specifically, the present invention provides the following [1] to

[18] .

[0013] [1] A curable composition comprising an epoxy resin, a thermally conductive filler, an amine compound (X) containing two or more amino groups, and a polyfunctional acrylate compound;

[0014] The amine compound (X) has a viscosity of 20 Pa·s or less at 25°C and 10 rpm as measured by an E-type viscometer, or has an oxyalkylene structure;

[0015] The content of the amine compound (X) is 15% by mass or more and 55% by mass or less based on the total resin components.

[0016] [2] The curable composition according to [1] above, wherein the content of the polyfunctional acrylate compound is 20% by mass or less relative to the total resin components.

[0017] [3] The curable composition according to [1] or [2] above, wherein the polyfunctional acrylate compound has 3 or more functional groups.

[0018] [4] The curable composition according to any one of [1] to [3] above, wherein the polyfunctional acrylate compound has 6 or more functional groups.

[0019] [5] The curable composition according to any one of [1] to [4] above, wherein the viscosity at 25°C measured by a rheometer is 300 Pa·s or less.

[0020] [6] The curable composition according to any one of [1] to [5] above, wherein the epoxy resin comprises a monofunctional epoxy resin.

[0021] [7] The curable composition according to any one of [1] to [6] above, wherein the amine compound (X) has an oxypropylene structure.

[0022] [8] The curable composition according to any one of [1] to [7] above, which contains 0.3% by mass or more and 2% by mass or less of water relative to the total amount of the curable composition.

[0023] [9] The curable composition according to any one of [1] to [8] above, wherein the amine compound (X) comprises an amine compound having three or more amino groups.

[0024]

[10] The curable composition described in any one of [1] to [9] above, which consists of a first component and a second component, wherein the first component contains the epoxy resin and the multifunctional acrylate compound and is filled in a first container, and the second component contains the amine compound (X) and is filled in a second container.

[0025]

[11] The curable composition described in

[10] above, wherein the difference between the viscosity (Pa·s) of the first component and the viscosity (Pa·s) of the second component at 25°C measured by a rheometer is 150 Pa·s or less.

[0026]

[12] The curable composition described in

[10] or

[11] above, wherein the ratio of the functional group concentration (mol / g) of the second agent to the functional group concentration (mol / g) of the first agent is 1.3 or more and 2.6 or less.

[0027]

[13] A curable composition comprising an epoxy resin, a thermally conductive filler, an amine compound (X) containing two or more amino groups, a multifunctional acrylate compound, and water,

[0028] The water content is 0.3% by mass or more and 2.0% by mass or less based on the total amount of the curable composition.

[0029]

[14] A container kit filled with the curable composition according to any one of

[10] to

[12] above, comprising a first container filled with the first agent and a second container filled with the second agent.

[0030]

[15] A curable composition comprising an epoxy resin, a thermally conductive filler, an amine compound (X) containing two or more amino groups, and a polyfunctional acrylate compound;

[0031] The amine compound (X) has a viscosity of 20 Pa·s or less at 25° C. and 10 rpm as measured by an E-type viscometer, or has an oxyalkylene structure.

[0032] The content of the amine compound (X) is 15% by mass or more and 70% by mass or less relative to the total resin component;

[0033] The amine compound (X) includes an amine compound having two amino groups.

[0034]

[16] A thermally conductive component comprising a cured product of the curable composition according to any one of [1] to

[13] and

[15] .

[0035]

[17] A battery pack comprising the heat-conducting component described in

[16] above.

[0036]

[18] The use of the curable composition described in any one of [1] to

[13] and

[15] above as at least one of a gap material between battery cells, a gap material between a battery cell and a module case, a gap material between a battery module and a battery pack case, and a gap material between a battery cell and a battery pack case.

[0037] Effects of the Invention

[0038] According to the present invention, there is provided a curable composition having low viscosity, rapid curing properties, and a prolonged pot life. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic diagram showing a container kit according to one embodiment.

[0040] Figure 2 is a schematic diagram showing a container kit according to one embodiment.

[0041] Figure 3 It is a perspective view showing a typical structure of a battery module according to the present invention.

[0042] Figure 4 It is a perspective view showing a typical structure of a battery cell included in a battery module.

[0043] Figure 5 It is a three-dimensional diagram showing a battery module with a module-free (CellToPack) structure. DETAILED DESCRIPTION

[0044] Hereinafter, the curable composition according to each embodiment of the present invention will be described in detail.

[0045] <<First embodiment>>

[0046] The curable composition according to the first embodiment of the present invention contains an epoxy resin, a thermally conductive filler, an amine compound (X) containing two or more amino groups, and a polyfunctional acrylate compound.

[0047] [Epoxy resin]

[0048] The curable composition of this embodiment includes an epoxy resin. By including an epoxy resin, the curable composition can easily adjust its adhesive strength to an appropriate range. The epoxy resin may be any compound having one or more epoxy groups. The epoxy resin may be a multifunctional epoxy resin having two or more epoxy groups, or a monofunctional epoxy resin having one epoxy group.

[0049] The curable composition of this embodiment preferably contains at least a multifunctional epoxy resin. By containing a multifunctional epoxy resin, the curable composition can appropriately form crosslinks and easily improve the adhesive strength.

[0050] More preferably, the curable composition contains a monofunctional epoxy resin in addition to the multifunctional epoxy resin. By further containing a monofunctional epoxy resin, the curable composition can prevent the crosslinking density after curing from becoming too high, thereby easily improving the elongation. Furthermore, by using a monofunctional epoxy resin, the viscosity of the curable composition before curing can be easily reduced.

[0051] When a polyfunctional epoxy resin and a monofunctional epoxy resin are used in combination, the mass ratio of the monofunctional epoxy resin to the polyfunctional epoxy resin (monofunctional / polyfunctional) is preferably 10 / 90 or more and 90 / 10 or less, more preferably 15 / 85 or more and 75 / 25 or less, further preferably 20 / 80 or more and 70 / 30 or less, and even more preferably 25 / 75 or more and 55 / 45 or less.

[0052] As the multifunctional epoxy resin, bifunctional or trifunctional multifunctional epoxy resins can be mentioned, and bifunctional epoxy resins are preferably used. Specific examples of the multifunctional epoxy resin include, but are not limited to, epoxy resins having aromatic rings such as phenol novolac epoxy resins, resorcinol epoxy resins, epoxy resins having a bisphenol skeleton, epoxy resins having a naphthalene skeleton, epoxy resins having a fluorene skeleton, epoxy resins having a biphenyl skeleton, epoxy resins having a bis(glycidyloxyphenyl)methane skeleton, epoxy resins having a xanthene skeleton, epoxy resins having an anthracene skeleton, and epoxy resins having a pyrene skeleton.

[0053] In addition, epoxy resins having an alicyclic skeleton, such as an epoxy resin having a dicyclopentadiene skeleton and an epoxy resin having an adamantane skeleton, can be mentioned.

[0054] In addition, aliphatic epoxy resins such as butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, glycerol polyglycidyl ether, and trimethylolpropane polyglycidyl ether can be mentioned.

[0055] Furthermore, hydrogenated products or modified products of the above-exemplified epoxy resins can also be used as the epoxy resin.

[0056] Examples of the epoxy resin having a bisphenol skeleton include epoxy resins having a bisphenol skeleton of bisphenol A type, bisphenol F type, or bisphenol S type.

[0057] Examples of the resorcinol-type epoxy resin include resorcinol diglycidyl ether.

[0058] Examples of the epoxy resin having a naphthalene skeleton include 1,2-diglycidylnaphthalene, 1,5-diglycidylnaphthalene, 1,6-diglycidylnaphthalene, 1,7-diglycidylnaphthalene, 2,7-diglycidylnaphthalene, triglycidylnaphthalene, and 1,2,5,6-tetraglycidylnaphthalene.

[0059] Examples of the epoxy resin having a fluorene skeleton include 9,9-bis(4-glycidyloxyphenyl)fluorene, 9,9-bis(4-glycidyloxy-3-methylphenyl)fluorene, 9,9-bis(4-glycidyloxy-3-chlorophenyl)fluorene, 9,9-bis(4-glycidyloxy-3-bromophenyl)fluorene, 9,9-bis(4-glycidyloxy-3-fluorophenyl)fluorene, 9,9-bis(4-glycidyloxy-3-methoxyphenyl)fluorene, 9,9-bis(4-glycidyloxy-3,5-dimethylphenyl)fluorene, 9,9-bis(4-glycidyloxy-3,5-dichlorophenyl)fluorene, and 9,9-bis(4-glycidyloxy-3,5-dibromophenyl)fluorene.

[0060] Examples of the epoxy resin having a biphenyl skeleton include 4,4'-diglycidylbiphenyl and 4,4'-diglycidyl-3,3',5,5'-tetramethylbiphenyl. Examples of the epoxy resin having a bis(glycidyloxyphenyl)methane skeleton include 1,1'-bis(2,7-glycidyloxynaphthyl)methane, 1,8'-bis(2,7-glycidyloxynaphthyl)methane, 1,1'-bis(3,7-glycidyloxynaphthyl)methane, 1,8'-bis(3,7-glycidyloxynaphthyl)methane, 1,1'-bis(3,5-glycidyloxynaphthyl)methane, 1,8'-bis(3,5-glycidyloxynaphthyl)methane, 1,2'-bis(2,7-glycidyloxynaphthyl)methane, 1,2'-bis(3,7-glycidyloxynaphthyl)methane, and 1,2'-bis(3,5-glycidyloxynaphthyl)methane.

[0061] Examples of the epoxy resin having a xanthene skeleton include 1,3,4,5,6,8-hexamethyl-2,7-bisglycidylmethoxy-9-phenyl-9H-xanthene, etc. Examples of the epoxy resin having an anthracene skeleton include epoxy resins having one or more anthracene skeletons and two or more epoxy groups or glycidyl groups per molecule.

[0062] Examples of the epoxy resin having a pyrene skeleton include epoxy resins having one or more pyrene skeletons and two or more epoxy groups or glycidyl groups per molecule.

[0063] Examples of the epoxy resin having a dicyclopentadiene skeleton include dicyclopentadiene dioxide and phenol novolac epoxy resins having a dicyclopentadiene skeleton. Examples of the epoxy resin having an adamantane skeleton include 1,3-bis(4-glycidyloxyphenyl)adamantane and 2,2-bis(4-glycidyloxyphenyl)adamantane.

[0064] Among the above-mentioned multifunctional epoxy resins, epoxy resins having an aromatic ring are preferred from the viewpoint of improving adhesive strength and mechanical strength, epoxy resins having a phenyl group are more preferred, and bisphenol-type epoxy resins having a bisphenol skeleton are even more preferred.

[0065] The multifunctional epoxy resins may be used alone or in combination of two or more.

[0066] Examples of the monofunctional epoxy resin include phenyl glycidyl ethers such as alkylphenyl glycidyl ethers represented by phenyl glycidyl ether, 4-tert-butylphenyl glycidyl ether, cresyl glycidyl ether, and nonylphenyl glycidyl ether, and monofunctional epoxy resins having an aromatic ring, such as 1-glycidyl naphthalene and 2-glycidyl naphthalene. The monofunctional epoxy resin having an aromatic ring is more preferably an epoxy resin having a phenyl group.

[0067] In addition, as monofunctional epoxy resins, aliphatic monofunctional epoxy resins are also preferred due to the high safety of the raw materials. Specific examples include glycidyl ethers of aliphatic alcohols. The aliphatic alcohol may be a branched or linear aliphatic alcohol, but a linear aliphatic alcohol is preferred for better elongation. Furthermore, aliphatic alcohols may have, for example, 4 to 24 carbon atoms, but preferably have 10 to 20 carbon atoms for better elongation. Furthermore, aliphatic alcohols are preferably saturated aliphatic alcohols for better elongation. Specific examples of glycidyl ethers of aliphatic alcohols include butyl glycidyl ether, decyl glycidyl ether, lauryl glycidyl ether, myristyl glycidyl ether, cetyl glycidyl ether, and stearyl glycidyl ether. The monofunctional epoxy resin may be other than those mentioned above, and examples thereof include monofunctional epoxy resins having no ether group but a glycidyl group, such as 1,2-butylene oxide and propylene oxide.

[0068] As the monofunctional epoxy resin, an aliphatic monofunctional epoxy resin is preferably used from the viewpoint of achieving good elongation, and among them, a glycidyl ether of an aliphatic alcohol is preferably used.

[0069] The monofunctional epoxy resins may be used alone or in combination of two or more.

[0070] The epoxy resin preferably includes an epoxy resin having an aromatic ring, particularly a phenyl group. The epoxy resin having an aromatic ring such as a phenyl group may be a monofunctional epoxy resin or a multifunctional epoxy resin. Aromatic rings, particularly phenyl groups, adopt a stacking structure based on π-π interactions after curing, and the epoxy resin easily forms a pseudo-crosslinked structure in the cured product. As a result, the mechanical strength and adhesive strength are easily increased. The epoxy resin preferably includes a multifunctional epoxy resin, and the multifunctional epoxy resin has an aromatic ring, particularly a phenyl group.

[0071] Epoxy resins having a molecular weight of, for example, 2000 or less can be used, preferably 1000 or less, and more preferably 500 or less. By using epoxy resins having a molecular weight of a certain value or less, the viscosity of the curable composition can be reduced, and a high filling of thermal conductive fillers can also be achieved. The molecular weight of the epoxy resin is, for example, 100 or more, preferably 150 or more, more preferably 200 or more, and even more preferably 250 or more. By making the molecular weight of the epoxy resin above a certain value, the crosslinking density can be prevented from becoming too high, and the elongation can be easily improved. It should be noted that the epoxy resin is preferably liquid at room temperature (25°C).

[0072] The epoxy equivalent of the epoxy resin is preferably 1000 g / eq or less, more preferably 500 g / eq or less, and even more preferably 375 g / eq or less, and is preferably 100 g / eq or more, more preferably 125 g / eq or more, and even more preferably 140 g / eq or more.

[0073] The epoxy resin may be liquid at room temperature (25°C). Furthermore, from the perspective of reducing viscosity, the viscosity of the epoxy resin at 25°C is preferably as low as possible, for example, 50 Pa·s or less, preferably 10 Pa·s or less. The viscosity of the epoxy resin at 25°C is not particularly limited, and may be, for example, 0.5 mPa·s or greater, or 1 mPa·s or greater.

[0074] The viscosity of the multifunctional epoxy resin at 25° C. may be, for example, 50 Pa·s or less, preferably 10 Pa·s or less, and may be 1 mPa·s or more, and is preferably 10 mPa·s or more, more preferably 100 mPa·s or more, for practical purposes.

[0075] On the other hand, the viscosity of a monofunctional epoxy resin at 25°C may be, for example, 10 Pa·s or less, preferably 1 Pa·s or less, and more preferably 100 mPa·s or less. Alternatively, it may be, for example, 0.5 mPa·s or more, 1 mPa·s or more, or 3 mPa·s or more. When the epoxy resin contains both a polyfunctional epoxy resin and a monofunctional epoxy resin, the viscosity of the monofunctional epoxy resin is preferably lower than that of the polyfunctional epoxy resin.

[0076] In addition, the viscosity of an epoxy resin and an amine compound mentioned later is the viscosity measured under the conditions of 10 rpm and 25°C using an E-type viscometer.

[0077] The content of the epoxy resin in the curable composition is, for example, more than 15 mass % and less than 80 mass % relative to all resin components. When the content of the epoxy resin is more than 15 mass %, it is easy to improve the bonding strength and elongation during all solidification. In addition, if it is less than 80 mass %, the composition of the uncured epoxy resin becomes difficult to exist, which can prevent the uncured component from hindering bonding or elongation from becoming low.

[0078] The content of the epoxy resin is preferably 20% by mass or more and 70% by mass or less, more preferably 25% by mass or more and 60% by mass or less, and even more preferably 30% by mass or more and 53% by mass or less.

[0079] It should be noted that in this specification, the total resin component refers to the total amount of the curing agent described later and the main agent that can be cured by the curing agent, and more specifically, it refers to the total amount of the amine compound (X) described later, curing agents other than the amine compound (X), epoxy resins, multifunctional acrylate compounds, and main agents other than epoxy resins and multifunctional acrylate compounds that can be cured by the curing agent.

[0080] [Amine compound (X)]

[0081] The amine compound (X) is a compound containing two or more amino groups. In addition, in the present embodiment, the viscosity of the amine compound (X) at 25°C and 10 rpm measured by an E-type viscometer is 20 Pa·s or less, or it has an oxyalkylene structure. In the present embodiment, by using the above specific amine compound (hereinafter sometimes referred to as amine compound (X1)), the initial curing proceeds immediately and has rapid curing properties, and the compressive load at the initial stage of curing is moderately low, and the compressive load at a low level can be maintained for a long time, and the usable time can also be extended. The principle is still uncertain, but it is speculated as follows. That is, in the initial stage of curing, the amine compound (X) and the multifunctional acrylate compound are preferentially cured, showing rapid curing properties, while on the other hand, the reaction of the amine compound (X) with the epoxy resin is suppressed, so the compressive load at the initial stage of curing is maintained at a low level. In particular, in the present embodiment, by using an amine compound (X) having a viscosity of 20 Pa·s or less, the initial viscosity of the composition is also reduced, and with this, the compressive load at the initial stage of curing is also reduced, so it is speculated that the compressive load is maintained at a low level for a long time, and the usable time is also extended. Furthermore, it is presumed that by using an amine compound (X) having an oxyalkylene structure, the compressive load after the reaction of the amine compound (X) is appropriately reduced due to its chemical structure, thereby extending the usable life. It should be noted that the oxyalkylene structure has the effect of reducing the compressive load due to its chemical structure, and therefore it is presumed that the usable life is extended even if the viscosity exceeds 20 Pa·s.

[0082] The amine compound (X) can react appropriately with the epoxy resin to cure by having the number of amino groups being 2 or more. The number of amino groups is not particularly limited, and is, for example, 10 or less, preferably 6 or less, and more preferably 4 or less. As described above, by setting the number of amino groups to a certain amount or less, the curing reaction is prevented from proceeding excessively, and the usable time is easily extended. In addition, from the perspective of rapid curing, the number of amino groups is preferably 3 or more.

[0083] The amino group contained in the amine compound (X) may be a primary amino group or a secondary amino group. However, from the perspective of reactivity and curing speed, the amine compound (X) preferably contains a primary amino group. The amine compound (X) preferably contains one or more primary amino groups per molecule, more preferably two or more primary amino groups, and even more preferably three or more primary amino groups. By providing the amine compound (X) with a large number of primary amino groups, rapid curing properties can be achieved. The number of primary amino groups per molecule of the amine compound (X) is, for example, six or less, preferably five or less, and more preferably four or less.

[0084] As described above, in one embodiment, the amine compound (X) has a viscosity of 20 Pa·s or less. When the viscosity is greater than 20 Pa·s, the viscosity before curing tends to be high, making it difficult to extend the usable time. To reduce the viscosity before curing and easily extend the usable time, the viscosity of the amine compound (X) is preferably 15 Pa·s or less, more preferably 12 Pa·s or less, even more preferably 5 Pa·s or less, and even more preferably 2 Pa·s or less.

[0085] The viscosity of the amine compound (X) is not particularly limited, but is, for example, 0.01 Pa·s or higher, preferably 0.05 Pa·s or higher, more preferably 0.1 Pa·s or higher, and even more preferably 0.5 Pa·s or higher.

[0086] In one embodiment, an amine compound having an oxyalkylene structure is used as the amine compound (X). When an amine compound having an oxyalkylene structure is used, the compressive load in the initial stage of curing is moderately low due to its molecular structure, and the compressive load can be easily maintained at a low level for a long time, thereby easily extending the usable life.

[0087] The viscosity of the amine compound (X) having an oxyalkylene structure can be 20 Pa·s or less, and the preferred viscosity value in this case is as described above. By having a viscosity of 20 Pa·s or less and an oxyalkylene structure, the compressive load of the amine compound (X) can be kept low for a long period of time, thereby easily extending the usable life.

[0088] However, in the present invention, an amine compound having a viscosity of more than 20 Pa·s can also be used as the amine compound (X) having an oxyalkylene structure.

[0089] The oxyalkylene structure preferably has a structure containing an oxyalkylene group having about 2 to 5 carbon atoms, and more preferably has an oxypropylene structure. Examples of the oxyalkylene structure include polyoxyalkylene structures formed by connecting two or more oxyalkylene structures, and specifically, polyoxyethylene structures, polyoxypropylene structures, polyoxybutylene structures, polyoxytetramethylene structures, oxyethylene-oxypropylene copolymer structures, and oxypropylene-oxybutylene copolymer structures. Among them, the amine compound (X) preferably has a polyoxypropylene structure, an oxyethylene-oxypropylene copolymer structure, and an oxypropylene-oxybutylene copolymer structure, and preferably has a polyoxypropylene structure.

[0090] Examples of the amine compound (X) having an oxyalkylene structure generally include aliphatic amines, and specific examples include polyoxyalkylene polyamines such as polyoxyethylenediamine, poly(oxyethylene / oxypropylene)diamine, poly(oxypropylene)diamine, poly(oxybutylene / oxypropylene)diamine, polyethylene glycol bis(propylamine), trimethylolpropane poly(oxypropylene)triamine, and glyceryl poly(oxypropylene)triamine. Among these, poly(oxypropylene)diamine, glyceryl poly(oxypropylene)triamine, and trimethylolpropane poly(oxypropylene)triamine are preferred, and trimethylolpropane poly(oxypropylene)triamine is more preferred.

[0091] The amine compound (X) not having an oxyalkylene structure may be an aliphatic amine, an aromatic ring-containing amine, or an amide amine. Specific examples of the aliphatic amine include, but are not limited to, branched or linear alkane diamines such as 1,3-diaminopropane, 2-methyl-1,5-diaminopentane, trimethylhexamethylenediamine, 2-methylpentamethylenediamine, and diethylaminopropylamine; and alicyclic polyamines such as 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, cyclohexanediamine, methylcyclohexanediamine, and isophoronediamine.

[0092] As the amidoamine, any type may be used as long as it is a low-viscosity type.

[0093] The aromatic ring-containing amine may be an amine in which the amino group is not directly bonded to the aromatic ring, such as meta-xylylenediamine and a reaction product of meta-xylylenediamine and styrene, or an aromatic amine in which the amino group is directly bonded to the aromatic ring.

[0094] As the amine compound (X) not having an oxyalkylene structure, an aromatic ring-containing amine in which the amino group is not directly bonded to an aromatic ring, such as a reaction product of m-xylylenediamine and styrene, or an aliphatic diamine is preferred in order to appropriately accelerate the curing speed and provide a certain compressive load in the initial stage of curing.

[0095] As the amine compound (X), among the above-mentioned ones, aliphatic amines and aromatic ring-containing amines in which the amino group is not directly bonded to the aromatic ring are preferred from the viewpoint of rapid curing and ensuring a certain compressive load in the initial stage of curing. Among them, polyoxyalkylene polyamines are more preferred.

[0096] The amine compound (X) may be used alone or in combination of two or more.

[0097] The molecular weight of the amine compound (X) is not particularly limited, and may be, for example, 5000 or less, preferably 3000 or less, more preferably 1000 or less, and even more preferably 600 or less. By using an amine compound (X) having a molecular weight of a certain value or less, the viscosity of the curable composition can be reduced, and a high loading of thermally conductive fillers can be achieved.

[0098] Alternatively, an amine compound (X) having a molecular weight of, for example, 100 or greater, preferably 110 or greater, more preferably 200 or greater, and even more preferably 300 or greater can be used. By setting the molecular weight of the amine compound (X) to a certain value or greater, the compressive load in the initial stage of curing is appropriately reduced, and the crosslinking density is prevented from becoming excessively high, thereby facilitating improved elongation and adhesive strength. It should be noted that the amine compound (X) may be liquid at room temperature (25° C.).

[0099] In addition, the molecular weight of the amine compound (X) and the said epoxy resin can be measured using a mass spectrometer (GC-MS or LC-MS), for example.

[0100] The active hydrogen equivalent of the amine compound (X) is not particularly limited, but is, for example, 15 g / eq or more, preferably 25 g / eq or more, more preferably 40 g / eq or more. It is, for example, 1000 g / eq or less, preferably 600 g / eq or less, more preferably 300 g / eq or less, and even more preferably 150 g / eq or less.

[0101] It is preferred that at least one of the amine compound (X) and the epoxy resin has a phenyl group. By having a phenyl group in at least one of the amine compound (X) and the epoxy resin, a pseudo-crosslinked structure is formed, which tends to improve the mechanical strength and adhesive strength of the curable composition.

[0102] In the first case, the content of the amine compound (X) in the curable composition is 15% to 55% by mass relative to the total resin components. If the content of the amine compound (X) is less than 15% by mass, the reaction between the polyfunctional acrylate compound and the amine compound (X) will not proceed rapidly, making it difficult to impart rapid curing properties. This is because simply because the amount of amine is too small, it is not possible to ensure sufficient amine for curing, and adhesive strength cannot be achieved.

[0103] On the other hand, if the content of the amine compound (X) exceeds 55% by mass, the amine compound (X) reacts not only with the polyfunctional acrylate compound but also largely with the epoxy resin, resulting in a large compressive load at an early stage of curing initiation, making it impossible to extend the usable time.

[0104] The content of the amine compound (X) is preferably 25% by mass to 52% by mass, more preferably 30% by mass to 50% by mass, and even more preferably 35% by mass to 48% by mass, based on the total resin component.

[0105] In addition, in 1st Embodiment, the content of an amine compound (X) means the content of the said amine compound (X1).

[0106] In the first case of the first embodiment, the amine compound (X) may be an amine compound having three or more amino groups. In the first case, the ratio of the amine compound having three or more amino groups to the amine compound (X) in the entire curable composition may be 50% by mass or more, preferably 70% by mass or more and 100% by mass or less, and more preferably 80% by mass or more and 100% by mass or less.

[0107] In the second case of the first embodiment, the content of the amine compound (X) in the curable composition is 15% by mass or more and 70% by mass or less relative to the total resin component. In the second case, the amine compound (X) may be an amine compound having two amino groups.

[0108] In the second case, if the content of the amine compound (X) in the curable composition is less than 15% by mass, the reaction between the polyfunctional acrylate compound and the amine compound (X) does not proceed rapidly, making it difficult to impart rapid curing properties. On the other hand, if the content of the amine compound (X) exceeds 70% by mass, the amine compound (X) reacts not only with the polyfunctional acrylate compound but also with the epoxy resin to a large extent, resulting in a large compressive load at an early stage of curing, making it impossible to extend the usable time.

[0109] In the second case, the content of the amine compound (X) is preferably 25% by mass to 65% by mass, more preferably 35% by mass to 64% by mass, and even more preferably 40% by mass to 63% by mass, based on the total resin component.

[0110] In the second case, the ratio of the amine compound having two amino groups to the amine compound (X) in the entire curable composition may be higher than 50 mass %, preferably 70 mass % or more and 100 mass % or less, more preferably 80 mass % or more and 100 mass % or less, and most preferably 100 mass %.

[0111] (Curing agent other than the amine compound (X1))

[0112] The curable composition of the present invention may contain a curing agent other than the above-mentioned amine compound (X1) as long as the effects of the present invention are not impaired. Specifically, examples thereof include an amine compound having a viscosity greater than 20 Pa·s and containing two or more amino groups (hereinafter sometimes referred to as "amine compound (X2)") and no oxyalkylene structure, and an amine compound containing only one amino group.

[0113] Examples of the amine compound (X2) include amine compounds that do not have an oxyalkylene structure and are solid at 25°C.

[0114] Specific examples include aromatic ring-containing amines such as m-phenylenediamine, p-phenylenediamine, p-phenylenediamine, toluene-2,4-diamine, toluene-2,6-diamine, mesitylene-2,4-diamine, mesitylene-2,6-diamine, 3,5-diethyltoluene-2,4-diamine, 3,5-diethyltoluene-2,6-diamine, biphenylenediamine, 4,4-diaminodiphenylmethane, 2,5-naphthalenediamine, 2,6-naphthalenediamine, 1,6-hexanediamine, aliphatic amines such as diamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, 1,14-tetradecanediamine, 1,16-hexadecanediamine, 1,18-octadecanediamine, 1,20-eicosanediamine, 2-methyl-1,8-octanediamine, 2-methyl-1,9-nonanediamine, and 2,7-dimethyl-1,8-octanediamine, polyamidoamines, and esteramines.

[0115] Examples of polyamidoamines include those obtained by reacting aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, and azelaic acid, fatty acids, and carboxylic acid compounds such as dimer acids with aliphatic polyamines or polyamines having a polyoxyalkylene chain. Examples of esteramines include 1,5-bis[1,2-bis(ethoxycarbonyl)ethylamino]-2-methylpentane, and commercially available products include "Dito Clair E-6347" manufactured by Daito Sangyo.

[0116] Furthermore, as long as the effects of the present invention are not impaired, the curable composition may also contain a monoamine having only one amino group as a curing agent capable of reacting with the epoxy resin and the polyfunctional acrylate compound described below. Specific examples include, but are not limited to, methoxypoly(oxyethylene / oxypropylene)-2-propylamine, diglycolamine, N-methylethanolamine, 3-butoxypropanolamine, ethylene glycolamine, propylene glycolamine, and polyamidoamine.

[0117] Furthermore, the curable composition may contain a curing agent other than the amine compound, unless the effects of the present invention are inhibited.

[0118] [Multifunctional acrylate compound]

[0119] The polyfunctional acrylate compound is a compound having a functional group number (i.e., the number of (meth)acryloyl groups) of 2 or more. In the present invention, the curable composition contains a polyfunctional acrylate compound, which reacts rapidly with the amine compound (X), exhibits rapid curing properties, and imparts a certain degree of adhesive strength in the initial stage of curing.

[0120] As the polyfunctional acrylate compound, various (meth)acrylates can be used, and esters of polyfunctional diols and (meth)acrylic acid are preferred.

[0121] In this specification, “(meth)acryloyl” refers to either acryloyl or methacryloyl, and “(meth)acrylate” refers to either acrylate or methacrylate, and the same applies to other similar terms.

[0122] Examples of bifunctional compounds among the polyfunctional acrylate compounds include 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 2-n-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, dimethyloltricyclodecane di(meth)acrylate, ethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, and dipropylene glycol di(meth)acrylate. meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, ethylene oxide-added bisphenol A di(meth)acrylate, propylene oxide-added bisphenol A di(meth)acrylate, ethylene oxide-added bisphenol F di(meth)acrylate, dimethylol dicyclopentadienyl di(meth)acrylate, ethylene oxide-modified isocyanuric acid di(meth)acrylate, 2-hydroxy-3-(meth)acryloyloxypropyl (meth)acrylate, carbonate diol di(meth)acrylate, polyether diol di(meth)acrylate, polyester diol di(meth)acrylate, polycaprolactone diol di(meth)acrylate, polybutadiene diol di(meth)acrylate, and the like.

[0123] Examples of the trifunctional or higher-functional compounds among the polyfunctional acrylate compounds include trimethylolpropane tri(meth)acrylate, glycerol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ethylene oxide-added trimethylolpropane tri(meth)acrylate, propylene oxide-added trimethylolpropane tri(meth)acrylate, and alkylene oxide-added trimethylolpropane tri(meth)acrylates such as caprolactone-modified trimethylolpropane tri(meth)acrylate. Alkyl-added isocyanurate tri(meth)acrylate, propylene oxide-added glycerol tri(meth)acrylate, di(trimethylolpropane) tetra(meth)acrylate, alkylene oxide-added pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tripentaerythritol octa(meth)acrylate, four pentaerythritol deca(meth)acrylate, tripentaerythritol hepta(meth)acrylate, four pentaerythritol nona(meth)acrylate, and the like.

[0124] The number of functional groups in the multifunctional acrylate compound is preferably 3 or more, more preferably 4 or more, and even more preferably 6 or more. A higher number of functional groups in the multifunctional acrylate compound improves rapid curing and tends to enhance adhesion in the initial stage of curing. It should be noted that the upper limit of the number of functional groups in the multifunctional acrylate compound is not particularly limited, and may be, for example, 10 or less, or 8 or less.

[0125] From the perspective of improving rapid curing properties and reducing the viscosity of the curable composition before curing, the molecular weight of the multifunctional acrylate compound is preferably below a certain value. The specific molecular weight of the multifunctional acrylate compound is, for example, 5000 or less, preferably 3000 or less, more preferably 1000 or less, and further preferably 700 or less. In addition, for the molecular weight of the multifunctional acrylate compound, for example, a variety of 150 or more, preferably 200 or more, more preferably 250 or more, and further preferably 450 or more can be used. By setting the molecular weight of the multifunctional acrylate compound to above a certain value, the compressive load in the initial stage of curing is appropriately reduced. In addition, the crosslinking density can be prevented from becoming higher than necessary, making it easier to improve the elongation and adhesion.

[0126] From the viewpoint of easily reducing the viscosity of the curable composition before curing, the polyfunctional acrylate compound is preferably liquid at room temperature (25° C.).

[0127] The functional group equivalent weight of the multifunctional acrylate compound is not particularly limited, but is preferably 500 g / eq or less, more preferably 300 g / eq or less, and even more preferably 150 g / eq or less. It is preferably 75 g / eq or more, more preferably 80 g / eq or more, and even more preferably 85 g / eq or more.

[0128] In the curable composition, the ratio of the number of functional groups of the multifunctional acrylate compound to the number of functional groups of the epoxy resin is preferably 0.1 to 2.5, preferably 0.3 to 1.5, more preferably 0.6 to 1.2, and even more preferably 0.75 to 1.1. If the ratio of the number of functional groups of the multifunctional acrylate compound is within the specified range, the amine compound (X) and the multifunctional acrylate compound are preferentially cured in the initial stage, exhibiting rapid curing properties. Meanwhile, the reaction between the amine compound (X) and the epoxy resin is suppressed, thereby maintaining a low compressive load in the initial stage of curing and extending the usable life.

[0129] The content of the multifunctional acrylate compound is, for example, 26% by mass or less, preferably 20% by mass or less, relative to the total resin composition. If the content of the multifunctional acrylate compound is reduced, for example, to 20% by mass or less, the multifunctional acrylate compound can prevent excessive initial curing, making it easier to maintain a low initial compression load. Furthermore, if the content of the multifunctional acrylate compound is reduced, moisture resistance is also improved. Therefore, even after curing and prolonged use under high temperature and high humidity, high bonding strength can be maintained. The content of the multifunctional acrylate compound is more preferably 18% by mass or less, and even more preferably 17% by mass or less.

[0130] In addition, in order to exhibit rapid curing properties and improve the adhesive strength in the initial stage of curing, the content of the multifunctional acrylate compound is preferably set to a certain amount or more, relative to the total resin component, for example, 3% by mass or more, preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 12% by mass or more.

[0131] It should be noted that the curable composition may contain compounds other than the aforementioned epoxy resins and multifunctional acrylate compounds as a base agent that can be cured with a curing agent. Examples of base agents other than epoxy resins and multifunctional acrylate compounds include monofunctional acrylate compounds. Monofunctional acrylate compounds are (meth)acrylates having only one (meth)acryloyl group.

[0132] In the present embodiment, the respective contents of the epoxy resin, the acrylate compound, and the amine compound in the curable composition are preferably adjusted according to the equivalent ratio of the functional groups contained in the respective compounds as represented by the following formula (1).

[0133] [A / (B+C)] = 1.1 or more and 2.9 or less (1)

[0134] In formula (1), A is the number of active hydrogen atoms in the amino group of the amine compound in the curable composition, B is the number of epoxy groups in the epoxy resin, and C is the number of (meth)acryloyl groups in the acrylate compound.

[0135] By setting the equivalent ratio of the functional groups to 1.1 or greater, the number of active hydrogen atoms in the amino groups becomes appropriate, allowing a certain reaction to proceed even in the initial stage of curing, thereby easily achieving rapid curing. Furthermore, by setting the equivalent ratio to 2.9 or less, the number of active hydrogen atoms in the amino groups does not become excessive, reducing the compressive load in the initial stage of curing and easily extending the pot life.

[0136] The equivalent ratio of the functional groups is more preferably 1.3 or greater, further preferably 1.35 or greater, and further preferably 1.4 or greater, and is more preferably 2.6 or less, further preferably 2.1 or less, and further preferably 1.8 or less.

[0137] In addition, the said equivalent ratio can be calculated by calculating the equivalent weight of an epoxy group, the equivalent weight of active hydrogen of an amino group, and the equivalent weight of a (meth)acryloyl group as follows.

[0138] The epoxy group equivalent can be obtained by dividing the content (g) of the epoxy resin contained in the curable composition by the epoxy equivalent (g / eq). However, when two or more epoxy resins are contained, the total value obtained by dividing the content (g) of each epoxy resin by the epoxy equivalent (g / eq) can be used.

[0139] The active hydrogen equivalent of the amino group can be obtained by dividing the amine content (g) in the curable composition by the active hydrogen equivalent (g / eq). However, when two or more amines are contained, the total value obtained by dividing the content (g) of each amine by the active hydrogen equivalent (g / eq) can be used.

[0140] Furthermore, the (meth)acryloyl equivalent can be obtained by dividing the content (g) of the acrylate compound contained in the curable composition by the (meth)acryloyl equivalent (g / eq). However, when two or more acrylate compounds are contained, the total value obtained by dividing the content (g) of each acrylate compound by the (meth)acryloyl equivalent (g / eq) can be used.

[0141] It should be noted that the epoxy equivalent weight (g / eq) can be obtained by dividing the molecular weight of the epoxy resin by the number of epoxy groups per molecule. Furthermore, the active hydrogen equivalent weight (g / eq) can be obtained by dividing the molecular weight of the amine by the number of active hydrogen groups per molecule. Furthermore, the (meth)acryloyl equivalent weight (g / eq) can be obtained by dividing the molecular weight of the acrylate compound by the number of (meth)acryloyl groups per molecule.

[0142] The molecular weight, number of epoxy groups, number of active hydrogen atoms, and number of (meth)acryloyl groups can be measured using a mass spectrometer (GC-MS or LC-MS). If only the molecular weight can be determined using a mass spectrometer, the number of epoxy groups and active hydrogen atoms per molecule can be determined using NMR (e.g., 1H NMR). If the sample is a mixture, it is preferable to separate the components using GPC (gel permeation chromatography) or HPLC (high performance liquid chromatography) before measuring the NMR.

[0143] It should be noted that, when the structural formula of an epoxy resin is known, the molecular weight and number of epoxy groups are those that can be calculated from the structural formula. Furthermore, when the structural formula of an amine is known, the molecular weight and number of active hydrogen atoms are those that can be calculated from the structural formula. The same applies to acrylate compounds.

[0144] It should be noted that the number of active hydrogen atoms in an amine is 1 in NHR2 (secondary amino group) and 2 in NH2R (primary amino group) (however, in NHR2 and NH2R, R is a functional group other than active hydrogen atoms, i.e., a portion other than NH or NH2 in the amine).

[0145] Relative to the volume of the entire curable composition, the content of the above-mentioned resin component in the curable composition is preferably 8% by volume or more and 65% by volume or less. If it is above the above lower limit, the thermally conductive filler can be appropriately dispersed in the heat-conducting component and the curable composition. In addition, it is also possible to prevent the viscosity of the curable composition from becoming higher than necessary. In addition, by being below the above upper limit, it is easy to make the curable composition contain a certain amount of thermally conductive filler. The content of the resin component in the curable composition is more preferably 15% by volume or more and 55% by volume or less, and further preferably 18% by volume or more and 45% by volume or less.

[0146] [water]

[0147] The curable composition in this embodiment may contain water. When the curable composition contains water, the water functions as a catalyst to promote the reaction between the amine compound (X) and the epoxy resin and the multifunctional acrylate compound, particularly the amine compound (X) and the multifunctional acrylate compound, thereby easily achieving rapid curing.

[0148] The water content is preferably 0.3% by mass or more and 2.0% by mass or less based on the total amount of the curable composition. If the water content is 0.3% by mass or more, the reaction between the amine compound (X) and the multifunctional acrylate compound can be appropriately promoted by water. On the other hand, if the water content is 2.0% by mass or less, it is less likely to cause problems such as excessive water causing a decrease in the physical properties of the cured product of the curable composition, or water causing excessive curing, thereby shortening the usable life.

[0149] The water content is preferably 0.5% by mass or more and 1.5% by mass or less, and more preferably 0.7% by mass or more and 1.2% by mass or less.

[0150] In addition, the content of the water in the curable composition can be determined by measuring it using the Karl Fischer method.

[0151] Furthermore, when the curable composition contains water, even with a relatively low content of the multifunctional acrylate compound, the reaction between the multifunctional acrylate compound and the epoxy resin can proceed efficiently, resulting in sufficiently rapid curing. Therefore, even when the curable composition contains water, the content of the multifunctional acrylate compound can be adjusted to be below the aforementioned upper limit, and can be further reduced, for example, to 10% by mass or less.

[0152] [Thermal conductive filler]

[0153] The curable composition of this embodiment contains a thermally conductive filler. When the curable composition contains a thermally conductive filler, the thermal conductivity of the thermally conductive component formed from the curable composition is improved.

[0154] Examples of the thermally conductive filler include metals, metal oxides, metal nitrides, metal hydroxides, carbon materials, oxides other than metals, nitrides, and carbides. Examples of the thermally conductive filler include spherical shapes and irregular powders.

[0155] Examples of thermally conductive fillers include metals such as aluminum, copper, and nickel; metal oxides such as aluminum oxide, magnesium oxide, and zinc oxide; and metal nitrides such as aluminum nitride. Examples of metal hydroxides include aluminum hydroxide. Examples of carbon materials include spherical graphite. Examples of oxides, nitrides, and carbides other than metals include quartz, boron nitride, and silicon carbide. Among these, aluminum oxide is preferred from the perspective of improving the heat dissipation of the thermally conductive component, and aluminum hydroxide is preferred when improving flame retardancy.

[0156] As the thermally conductive filler, one of the above-mentioned substances may be used alone, or two or more of them may be used in combination.

[0157] The average particle size of the thermally conductive filler is preferably 0.1 μm to 200 μm, more preferably 0.5 μm to 150 μm, and even more preferably 1 μm to 110 μm.

[0158] The thermally conductive filler preferably uses a small thermally conductive filler having an average particle size of 0.1 μm to 5 μm and a large thermally conductive filler having an average particle size of more than 5 μm and 200 μm to 200 μm in combination. Using thermally conductive fillers having different average particle sizes can increase the filling rate.

[0159] The average particle size of the thermally conductive filler can be measured by observation using an electron microscope, etc. More specifically, for example, the particle sizes of 50 random thermally conductive fillers can be measured using an electron microscope or an optical microscope, and the average value (arithmetic mean) can be taken as the average particle size.

[0160] Relative to the volume of the entire curable composition, the content of the thermally conductive filler in the curable composition is preferably 30% by volume or more and 90% by volume or less. If it is above the above lower limit, a certain thermal conductivity can be imparted to the curable composition. In addition, by setting the content of the thermally conductive filler to below the above upper limit, the thermally conductive filler can be appropriately dispersed in the curable composition, and the viscosity of the curable composition can also be prevented from increasing to more than necessary. It should be noted that, in the present invention, by making the curable composition low in viscosity, it is easy to increase the content of the thermally conductive filler. The content of the thermally conductive filler in the curable composition is more preferably 40% by volume or more and 80% by volume or less, and further preferably 50% by volume or more and 75% by volume or less.

[0161] The content of the thermally conductive filler in the curable composition, expressed in parts by mass, is preferably 150 parts by mass or more and 3000 parts by mass or less, more preferably 200 parts by mass or more and 2000 parts by mass or less, and even more preferably 300 parts by mass or more and 1000 parts by mass or less, relative to 100 parts by mass of the resin component.

[0162] [Other additives]

[0163] The curable composition of the present invention may contain additives other than those mentioned above. Examples of such additives include dispersants, curing catalysts for accelerating the reaction between a main agent other than water and a curing agent, reaction rate controllers (reaction retarders) for inhibiting the reaction between the main agent and the curing agent, thixotropy-imparting agents, flame retardants, plasticizers, antioxidants, colorants, and the like.

[0164] As described above, the curable composition of the present invention may contain a dispersant. As a dispersant, a polymer dispersant may be mentioned. As a polymer dispersant, a polymer compound having a functional group may be mentioned. As a polymer compound, for example, acrylic acid, vinyl, polyester, polyurethane, polyether, epoxy, polystyrene, amino, silicone, etc. may be mentioned. In addition, as a functional group, a carboxyl group, a phosphoric acid group, a sulfonic acid group, a carboxylate group, a phosphoric acid ester group, a sulfonic acid ester group, a hydroxyl group, an amino group, a quaternary ammonium salt group, an amide group, etc. may be mentioned. In addition, as a dispersant, substances other than polymer dispersants may be used, for example, an alkoxysilane compound may be used.

[0165] The content of the dispersant in the curable composition is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 3 parts by mass, and even more preferably 0.07 to 2 parts by mass, relative to 100 parts by mass of the resin component.

[0166] <Viscosity>

[0167] The viscosity of the curable composition of the present invention is preferably 300 Pa·s or less. The viscosity is measured using a rheometer with a Peltier plate, while the sample temperature is adjusted to 25°C and a 25 mm φ parallel plate is used while continuously varying the shear rate within a range of 0.0001 to 100 1 / s. The viscosity is the value obtained at a shear rate of 3.16 1 / s. For example, the rheometer "MCR-302e" manufactured by Antenna Partners Inc. can be used.

[0168] However, for a two-component curable composition, the viscosity after mixing the first and second components can be measured. However, in this case, the curing speed may be too fast to perform a high-precision evaluation. Therefore, the viscosity of the first and second components before mixing can be measured for evaluation.

[0169] However, as described later, when measuring the viscosity of the first and second components before mixing, the sample is placed in a rheometer and allowed to stand for 10 minutes before measuring the viscosity.

[0170] By making the viscosity of the curable composition 300Pa s or less, the curable composition can be easily applied to the adherend, and the workability is improved. In addition, even for narrow gaps, it is easy to fill the curable composition. The above viscosity is more preferably 250Pa s or less, and further preferably 200Pa s or less. In addition, the above viscosity is, for example, 10Pa s or more. Considering the fact that dripping is not likely to occur when filling a certain amount of thermally conductive filler, it is preferably 30Pa s or more, and more preferably 50Pa s or more.

[0171] <Adhesion Strength>

[0172] The curable composition of the present invention can ensure high bonding strength by increasing the bonding strength after curing. Therefore, the bonding strength of the curable composition after curing is as high as possible, for example, 1 MPa or more, preferably 1.5 MPa or more, more preferably 2 MPa or more. The bonding strength of the curable composition after curing is as high as possible, but is practically, for example, 25 MPa or less.

[0173] In addition, for the curable composition of the present invention, by making the elongation under the maximum load after curing be more than a certain value, flexibility can be ensured, reliability etc. can be easily improved. The elongation under the maximum load of the curable composition of the present invention after curing is, for example, more than 0.4mm, preferably more than 0.5mm, more preferably more than 0.6mm. In addition, the elongation under the maximum load is not particularly limited, and from the perspective of giving a certain bonding strength, it is, for example, less than 3mm, preferably less than 2mm.

[0174] The adhesive strength (also referred to as "process adhesive strength") of the curable composition of the present invention after being placed under an environment of 18°C ​​and 20% RH for 1 hour is also preferably above a certain value. The process adhesive strength represents the adhesive strength at the initial stage of curing. The higher the value, the better the tendency of rapid curing. When the process adhesive strength is above a certain value, the rapid curing property of the curable composition becomes good. The process adhesive strength is preferably above 0.05MPa, more preferably above 0.1MPa, and further preferably above 0.25MPa. There is no particular limit to the upper limit of the process adhesive strength. From the perspective of easily reducing the compressive load described later, it is, for example, below 1MPa.

[0175] It should be noted that the bonding strength and elongation under maximum load of the curable composition after the above-mentioned curing can be measured by the following test method. First, prepare two PET plates of 25mm×100mm and a thickness of 2mm. Then, the two prepared plates are overlapped with each other at the ends via the curable composition, and then the curable composition is cured, thereby bonding the ends of the plates to obtain a measurement sample. It should be noted that the ends of the plates are bonded using a cured product of a curable composition of 25mm×5mm and a thickness of 1mm. The maximum load when the obtained measurement sample is stretched in the longitudinal direction using a tensile testing machine is used as the bonding force, and the elongation of the cured product under the maximum load is used as the elongation under the maximum load. The stretching speed can be set to 10mm / second.

[0176] It should be noted that the curing of the curable composition can be performed by completely curing the curable composition between the PET plates. Specifically, for example, in the case of a two-component type, the first component and the second component are mixed, applied between the PET plates, and then left at room temperature (25°C) for 168 hours.

[0177] On the other hand, the process bonding strength can be measured using the same method as the bonding strength measurement, except that a 25 mm × 100 mm aluminum plate and a glass fiber reinforced PET substrate with a thickness of 2 mm are used instead of the PET plate as the substrate, and the curable composition is cured by leaving it in an environment of 18°C ​​and 20% RH for 1 hour.

[0178] <Thermal conductivity>

[0179] The thermal conductivity of the cured product of the curable composition of the present invention is preferably 1.3 W / (m·K) or more, more preferably 1.5 W / (m·K) or more, and further preferably 1.7 W / (m·K) or more. The curable composition has good thermal conductivity by making the thermal conductivity of the cured product be above these lower limits. Therefore, for example, when used in a battery cell assembly, the heat generated by the battery cell can be effectively transferred to the module housing and the battery pack via the cured product (heat conductive component) of the curable composition, and an excessive rise in the battery cell temperature can be suppressed. The higher the above-mentioned thermal conductivity, the better, but in practical use, it is, for example, 7.0 W / m·K or less.

[0180] Thermal conductivity can be measured by a method based on ASTM D5470-06.

[0181] Specifically, the curable composition having a larger thickness than that when measuring is configured in a manner covering the measuring die head on the heating element side, and then clamped with a radiator, the thickness of the curable composition compressed to 1.0 mm, 1.5 mm, and 2.0 mm with a load of 30 psi is determined to measure the thermal resistance under each thickness. The thickness can be adjusted with a spacer. For these three thermal resistance values, a chart with a horizontal axis being thickness and a vertical axis being thermal resistance value is made, and an approximate straight line at three points is obtained by the method of least squares. Furthermore, the slope of the approximate straight line is used as thermal conductivity.

[0182] In the present invention, the compressive load of the curable composition when cured at 35°C for 10 minutes is preferably 1500N or less, more preferably 1000N or less, and even more preferably 800N or less. The lower limit of the compressive load is not particularly limited; however, from the perspective of easily obtaining a certain bonding strength during temporary bonding, it is, for example, 100N. When the compressive load is below a specified value, the curable composition exhibits a certain degree of flexibility during the initial curing phase, facilitating temporary bonding. Furthermore, by lowering the compressive load, the usable life is also likely to be extended.

[0183] The compressive load is a load applied when a jig is pressed against the curable composition cured under the predetermined conditions described in the Examples.

[0184] <Provide form>

[0185] The curable composition of the present embodiment may be in the form of a one-component type or a two-component type comprising a first component and a second component. From the viewpoint of storage stability, the two-component type is preferred.

[0186] In a two-component curable composition, the mass ratio of the first component to the second component (second component / first component) is preferably 1 or a value close to 1, specifically, preferably 0.9 to 1.1, more preferably 0.95 to 1.05. By setting the mass ratio of the first component to the second component to 1 or a value close to 1, the preparation of the curable composition becomes easier.

[0187] In a two-component curable composition, it is preferred that both the first and second components be liquid at room temperature (25°C) and have the same viscosity, or, if different, a small difference in viscosity. By ensuring that the first and second components have the same or similar viscosities, the curable composition can be easily mixed uniformly.

[0188] Specifically, the viscosity difference between the first and second agents [Pa·s] is preferably 150 Pa·s or less, more preferably 100 Pa·s or less, and even more preferably 50 Pa·s or less. The viscosity difference may be 0 Pa·s or more.

[0189] The viscosity of the first and second agents is not particularly limited, but is preferably 10 Pa·s to 300 Pa·s, more preferably 30 Pa·s to 250 Pa·s, and even more preferably 40 Pa·s to 200 Pa·s.

[0190] It should be noted that the viscosity of the first and second agents mentioned herein can be measured as follows: using a rheometer (e.g., the rheometer "MCR-302e" manufactured by Antron Plc), the sample temperature is adjusted to 25°C using a Peltier plate, and after the sample is placed and allowed to stand for 10 minutes using a 25 mm φ parallel plate, the shear rate is continuously varied within the range of 0.0001 to 100 (1 / sec) while the viscosity is measured. The viscosity values ​​described above are those obtained when the shear viscosity is 3.16 (1 / sec).

[0191] More specifically, the two-component curable composition may include a first component containing a main component such as an epoxy resin and a multifunctional acrylate compound that is cured by a curing agent, and a second component containing a curing agent such as an amine compound (X).

[0192] In the two-component curable composition, the first component contains a main component (ie, epoxy resin and polyfunctional acrylate compound), but may not contain a curing agent (ie, amine compound (X)).

[0193] On the other hand, the second agent includes a curing agent (i.e., an amine compound (X)). In addition, the second agent may include a curing catalyst as needed. For example, when water is used as a catalyst, water may be included in the second agent. In addition, the main agent (i.e., an epoxy resin and a multifunctional acrylate compound) may not be included. However, as long as the second agent does not react with the curing agent, a part of the main agent (i.e., an epoxy resin and a multifunctional acrylate compound) may also be included.

[0194] In addition, the thermally conductive filler is contained in at least one of the first agent and the second agent, and is preferably contained in both the first agent and the second agent.

[0195] Therefore, it is preferred that the first component contain a main component (i.e., an epoxy resin and a multifunctional acrylate compound) and a thermally conductive filler, and the second component contain a curing agent (i.e., an amine compound) and a thermally conductive filler. Furthermore, it is further preferred that the first component does not contain a curing agent such as an amine compound, and the second component does not contain a main component. Therefore, it is further preferred that the main component of the curable composition is entirely contained in the first component, and the curing agent of the curable composition is entirely contained in the second component.

[0196] As mentioned above, the thermally conductive filler is preferably included in both the first and second components, and more preferably is included approximately equally in both. Specifically, the ratio (mass ratio) of the thermally conductive filler content in the second component to the thermally conductive filler content in the first component is preferably 0.67 to 1.5, more preferably 0.83 to 1.2, and even more preferably 0.91 to 1.1. By distributing the thermally conductive filler approximately equally between the first and second components, the viscosity difference between the first and second components is easily reduced, and the volume ratio of the first to second components is also easily close to 1.

[0197] Additionally, the viscosity difference between the first and second doses can be adjusted by varying the viscosities of the epoxy resin, multifunctional acrylate compound, and amine compound used. For example, to reduce the viscosity of the first dose containing epoxy resin, a low-viscosity epoxy resin can be used or the content of the low-viscosity epoxy resin can be increased. Similarly, the viscosity of the first dose can be adjusted by varying the type and amount of acrylate compound. Furthermore, the viscosity can be lowered by adding a dispersant or plasticizer.

[0198] When the densities of the first and second components are close, mixing can be easier. Therefore, a smaller density difference is preferred. Specifically, the ratio of the density of the first component to the density of the second component (also referred to as the density ratio) is preferably 0.7 to 1.4, more preferably 0.8 to 1.2, and even more preferably 0.9 to 1.1. To reduce the density ratio, the thermally conductive filler content of the first and second components can be adjusted within the above range.

[0199] In a two-component type, a dispersant and other additives may be contained in one or both of the first and second components as needed. For example, if both the first and second components contain a thermally conductive filler, a dispersant may be contained in both components.

[0200] In a two-liquid curable composition, the ratio of the functional group concentration (mol / g) of the second agent to the functional group concentration (mol / g) of the first agent is preferably 1.1 or more and 2.9 or less. By setting the functional group concentrations of the first and second agents within the above range, if the first and second agents are mixed in a volume ratio of 1:1, the main agent and the curing agent react in an appropriate equivalent ratio, resulting in rapid curing and a longer usable life. In addition, the curable composition is easily cured in a manner that maintains appropriate bonding strength and does not become too dense in the three-dimensional crosslinking, thereby having an appropriate elastic modulus.

[0201] The functional group concentration ratio is more preferably 1.3 or greater, further preferably 1.35 or greater, and further preferably 1.4 or greater, and is more preferably 2.6 or less, further preferably 2.1 or less, and further preferably 1.8 or less.

[0202] It should be noted that the functional group concentration refers to the concentration of active hydrogen atoms of epoxy groups, (meth)acryloyl groups, and amino groups contained in the first or second dose. In the first dose, epoxy groups and (meth)acryloyl groups are functional groups, and the total number of epoxy groups and (meth)acryloyl groups per unit weight (g) is the functional group concentration. In the second dose, active hydrogen atoms of amino groups are functional groups, and the number of active hydrogen atoms of amino groups per unit weight (g) is the functional group concentration.

[0203] In the case of a two-liquid curable composition, it is preferred that the first agent and the second agent be filled in different containers. Specifically, the first agent can be filled in a first container and the second agent can be filled in a second container. The first container and the second container can be separate or integrated. By integrating the first container and the second container, it is easy to supply the container kit to the demander. It should be noted that in this specification, the first container filled with the first agent and the second container filled with the second agent are sometimes collectively referred to as a container kit.

[0204] As the container, there are syringes, cartridges, barrels, drums, etc., but not limited thereto. For example, when filling a syringe, it is preferably made into a two-liquid parallel type syringe. Figure 1As shown, a two-liquid parallel syringe 30 is a syringe in which a first syringe 31 constituting a first container and a second syringe 32 constituting a second container are arranged side by side to form an integral unit. The first dose 35 and the second dose 36 filled in syringes 31 and 32 can be discharged from the syringes as a dispenser and mixed.

[0205] In addition, when using a cartridge, the container set is composed of a first cartridge constituting the first container and a second cartridge constituting the second container, and these cartridges may also be integrated. It should be noted that the cartridge is usually set in a syringe (e.g., a first syringe, a second syringe), etc., and each syringe serves as a dispenser. The first dose delivered from the first cartridge and the second dose delivered from the second cartridge are discharged from the respective discharge ports of the first syringe and the second syringe and mixed.

[0206] The mixing of the first and second agents can be carried out by using a mixer such as a static mixer. Figure 1 As shown, the first syringe 31 is connected to the discharge port 31A and the second syringe 32 is connected to the discharge port 32A, so that the first agent 35 and the second agent 36 discharged from the respective discharge ports 31A and 32A can be mixed inside the mixer 38. The mixture (curable composition) obtained by mixing in the mixer 38 can be discharged from the discharge port 39 of the mixer 38.

[0207] Each syringe 31, 32 may have a structure in which the openings of the barrels 33A, 34A filled with the first dose 35 and the second dose 36, respectively, are closed by the caps 33B, 34B. Figure 1 In the illustrated syringe 30 , the first dose 35 and the second dose 36 can be discharged from the discharge ports 31A and 32A by removing the respective caps 33B and 34B and squeezing them out using a piston (not shown) inserted from the opening.

[0208] In addition, when using drums and cans, the container group such as Figure 2 As shown, a first can 41 constituting a first container and filled with a first agent 45 can be provided, and a second can 42 constituting a second container and filled with a second agent 46 can be provided. It should be noted that each can 41 or 42 includes, for example, a container body 43A or 44A having an opening and filled with the first agent 45 and the second agent 46, and a lid 43B or 44B that closes the opening of each container body 43A or 44B.

[0209] <Method for Preparing Curable Composition>

[0210] In the case of a two-liquid curable composition of the present invention, the first agent and the second agent can each be obtained by mixing the components constituting the first agent and the second agent, respectively. Similarly, in the case of a single-liquid type, it can be obtained by mixing the components constituting the curable composition. The method of mixing the components is not particularly limited. For example, it can be prepared by adding a thermally conductive filler as needed to the main agent and the curing agent, and further adding additives such as a dispersant as needed, and then stirring or kneading.

[0211] Alternatively, thermally conductive fillers can be surface-treated with a dispersant before being mixed with the main agent or curing agent. By pre-treating the surface of the thermally conductive filler with a dispersant, the surface is pre-modified with the dispersant. The pre-modified thermally conductive filler is then mixed with the main agent and curing agent to prepare the first and second doses.

[0212] The method for pre-treating the surface using a dispersant is not particularly limited and can be performed using known methods, such as wet treatment methods and dry treatment methods. In wet treatment methods, for example, a treatment solution formed by dispersing or dissolving a dispersant in a solvent is added to a thermally conductive filler and mixed. The mixture is then dried, heated, cleaned, etc. to allow the dispersant to bind or adhere to the surface of the thermally conductive filler. Alternatively, a dry treatment method is a method of performing surface treatment without using a dispersion medium. Specifically, a dispersant is mixed with the thermally conductive filler and stirred using a mixer, etc., followed by a heat treatment to allow the dispersant to bind or adhere to the surface of the thermally conductive filler.

[0213] <<Second embodiment>>

[0214] The curable composition according to the second embodiment of the present invention contains an epoxy resin, a thermally conductive filler, an amine compound (X) containing two or more amino groups, a polyfunctional acrylate compound, and water.

[0215] In this embodiment, by further including water in the curable composition comprising an epoxy resin, a thermally conductive filler, an amine compound (X), and a multifunctional acrylate compound, initial curing proceeds immediately, thereby exhibiting rapid curing properties, and the compressive load can be maintained at a moderately low state for a long period of time during the initial curing stage, thereby extending the usable time.

[0216] In the second embodiment, the water content is 0.3% to 2% by mass relative to the total amount of the curable composition. In the second embodiment, if the water content is less than 0.3% by mass, it is difficult to maintain the compressive load at a moderately low level for a long period of time while accelerating the initial curing, making it difficult to achieve rapid curing while extending the usable life. In addition, if the water content exceeds 2.0% by mass, the physical properties of the cured product of the curable composition may be degraded due to the water, or the curing may be excessively advanced due to the water, resulting in a shortened usable life.

[0217] In the second embodiment, the water content is preferably 0.5 mass % to 1.5 mass % based on the total amount of the curable composition, and more preferably 0.7 mass % to 1.2 mass %.

[0218] In the first embodiment, the amine compound (X) containing two or more amino groups has a viscosity of 20 Pa·s or less at 25°C and 10 rpm, or has an oxyalkylene structure. However, in the second embodiment, the amine compound (X) containing two or more amino groups may be the amine compound (X1), but is not necessarily the amine compound (X1), and may be an amine compound (X2) other than the amine compound (X1), or may be a combination of the amine compound (X1) and the amine compound (X2). It should be noted that the details of the amine compound (X1) and the amine compound (X2) are as described above, and therefore their description is omitted.

[0219] In the second embodiment, the content of the amine compound (X) is similar to the first embodiment, and may be 15% by mass or more and 55% by mass or less relative to the total resin component, preferably 25% by mass or more and 50% by mass or less, and more preferably 30% by mass or more and 48% by mass or less. In the second embodiment, the content of the amine compound (X) refers to the total content of the amine compound (X1) and the amine compound (X2). The content of the amine compound (X) may be outside the above range, for example, 10% by mass or more and 65% by mass or less.

[0220] In the second embodiment, the configuration other than the amine compound (X) is the same as in the first embodiment, and thus a description thereof is omitted. Specifically, in the second embodiment, details of the epoxy resin, thermally conductive filler, multifunctional acrylate compound, other additives, viscosity, adhesive strength, process adhesive strength, thermal conductivity, compressive load, supply method, and preparation method are as described in the first embodiment, and thus a description thereof is omitted.

[0221] [Thermal conductive components]

[0222] The curable composition of the present invention can be used as a heat-conducting component. The curable composition of the present invention becomes a heat-conducting component by curing. The heat-conducting component of the present invention is a cured product of the curable composition, comprising a polymer matrix and a heat-conducting filler. The polymer matrix is ​​composed of an epoxy resin cured product obtained by curing a resin component comprising an epoxy resin, a multifunctional acrylate compound and an amine compound (X), and the heat-conducting filler is dispersed in the polymer matrix and retained in the polymer matrix. The heat-conducting component can be arranged between two components such as a heating element and a heat sink for use. For the heating element, heat-generating electronic components such as batteries can be cited. For the heat sink, cooling components such as housings, radiators, and cooling plates can be cited.

[0223] [use]

[0224] The curable composition and thermally conductive component of the present invention can be used for various applications, for example, can be used for various electronic equipment applications such as battery assemblies such as lithium-ion battery (LiB) assemblies, power electronic equipment, electronic packaging, LEDs, solar cells, and power grids. Among them, it is preferably used in battery assemblies, and more preferably in LiB assemblies. Therefore, in a preferred embodiment of the present invention, a battery assembly having the above-mentioned thermally conductive component is provided. It should be noted that battery assemblies such as LiB assemblies can be preferably used in automobiles.

[0225] In battery assembly applications, the curable composition and thermally conductive component of the present invention are preferably used as gap fillers in battery assemblies. Furthermore, in one embodiment, the curable composition and thermally conductive component of the present invention are preferably used in battery modules, and more preferably as gap fillers in battery modules. The following describes an example of the thermally conductive component of the present invention being used in a battery module.

[0226] The battery module includes a gap material formed from a thermally conductive component, multiple battery cells, and a module housing that houses the multiple battery cells. The gap material is located within the module housing. The gap material formed from the thermally conductive component is filled between the battery cells and between the battery cells and the module housing. The filled gap material adheres tightly to the battery cells and the module housing. Thus, the gap material between the battery cells maintains the separation between the battery cells. Furthermore, the gap material between the battery cells and the module housing adheres tightly to both the battery cells and the module housing, transferring heat generated in the battery cells to the module housing.

[0227] Figure 3 The specific configuration of the battery module is shown. Figure 4 The specific structure of each battery cell is shown in FIG. Figure 3 As shown, a plurality of battery cells 11 are arranged inside the battery module 10. Each battery cell 11 is formed by laminating and enclosing it in a flexible outer film, and the overall shape is a flat body with a thickness smaller than the height and width. Figure 4As shown, the positive electrode 11a and the negative electrode 11b of such a battery cell 11 are exposed to the outside, and the center portion 11c of the flat surface is formed to be thicker than the end portion 11d to be pressed.

[0228] like Figure 3 As shown in FIG. 1 , each battery cell 11 is arranged so that its flat surfaces face each other. Figure 3 In the structure of FIG, the gap material 13 is not filled to cover the entirety of the plurality of battery cells 11 housed within the module case 12. Instead, the gap material 13 is filled to fill a portion (the bottom portion) of the gap within the module case 12. The gap material 13 is filled between the battery cells 11 and between the battery cells 11 and the module case 12, and adheres closely to the surfaces of the battery cells 11 and the inner surface of the module case 12 in this portion.

[0229] Although the gap material 13 filling the gap between the battery cells 11 is adhered to the surfaces of the two battery cells 11, the gap material 13 itself has appropriate elasticity and flexibility. Therefore, even if an external force is applied that would cause the gap between the battery cells 11 to shift, the strain caused by the external force can be alleviated. Therefore, the gap material 13 has the function of maintaining the spacing between the battery cells 11.

[0230] The gap material 13 filling the gap between the battery cell 11 and the inner surface of the module case 12 is also tightly bonded to the surface of the battery cell 11 and the inner surface of the module case 12. As a result, heat generated inside the battery cell 11 is transferred through the gap material 13 bonded to the surface of the battery cell 11 to the inner surface of the module case 12, which is in close contact with the other surface of the gap material 13.

[0231] The gap material 13 can be formed in the battery module 10 by applying a liquid curable composition using a conventional dispenser and then curing the liquid curable composition. Furthermore, as described above, the curable composition of the present invention has a low viscosity, thus improving workability when forming the gap material 13.

[0232] When forming the gap material 13, as mentioned above, a two-component curable composition is preferably used. This type of composition is easy to store, and if mixed immediately before use, it is less likely to solidify during application using a dispenser, allowing for rapid curing after application. Furthermore, application using a dispenser is also preferred because it allows the liquid curable composition to be filled deeper into the housing 12 of the battery module 10.

[0233] It is preferred that the gap material 13 covering the battery cells 11 covers 20 to 40% of each battery cell 11 on one side of the battery cell 11. By setting it to 20% or more, the battery cells 11 can be kept stable. In addition, by fully covering the battery cells that generate a large amount of heat, the heat dissipation efficiency becomes good. On the other hand, by setting it to 40% or less, the heat generated by the battery cells 11 can be effectively dissipated, and it is also possible to prevent an increase in weight and deterioration in operability. In addition, in order to achieve good heat dissipation efficiency, it is preferred to cover the side of the battery cell 11 where the electrodes 11a and 11b are located with the gap material 13, and it is more preferred to cover the entire electrodes 11a and 11b with the gap material 13. As described above, the battery module 10 can release the heat generated by the battery cells 11 to the module case 12 via the gap material 13.

[0234] The gap material 13 is also preferably used in a battery pack having multiple battery modules 10 therein. A battery pack typically includes multiple battery modules 10 and a battery pack case that houses the multiple battery modules 10. In such a battery pack, a gap material 13 can be provided between the battery modules 10 and the battery pack case. This allows the heat released to the module case 12 as described above to be further dissipated to the battery pack case, enabling efficient heat dissipation.

[0235] In the above description, examples are described in which the battery module is a battery module or a battery module having a battery module. However, the present invention can also be applied to a battery module not having a battery module, and is preferably applied to a battery module having a module-less structure, for example.

[0236] Figure 5 : A schematic diagram of a battery assembly with a module-free structure is shown in FIG. The battery assembly 20 with a module-free structure includes a plurality of battery cells 21 and a battery pack shell, and the plurality of battery cells 21 are bonded to a base member 25 constituting the battery pack shell via a gap material 23 composed of a heat-conducting component (a cured product of a curable composition). The base member 25 may also constitute a cooling plate, etc. It should be noted that the formation of the gap material 23 in the battery assembly 20 can be carried out in the same manner as the formation of the gap material 13 in the above-mentioned battery module, for example, a general dispenser can be used. Since the curable composition of the present invention has a low viscosity, the operability when forming the gap material 23 is also good. In addition, the curable composition of the present invention has a fast curing property, and the compressive load can be reduced in the initial stage of curing, which can extend the service life. Therefore, in a battery assembly with a module-free structure, the battery cells 21 can also be bonded to the base member 25 with high operability.

[0237] Example

[0238] Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

[0239] [Viscosity of each component]

[0240] The viscosity of the epoxy resin, amine compound, and acrylate compound was measured using an E-type viscometer at 10 rpm and 25° C. As the E-type viscometer, “TV-22” manufactured by Toki Sangyo Co., Ltd. or the like was used.

[0241] [Adhesion test]

[0242] The adhesive strength of the cured product of the curable composition at 25° C. was measured by the following method.

[0243] First, as a substrate, two PET plates with a width of 25 mm, a length of 100 mm and a thickness of 2 mm (trade name "PET-6010", manufactured by Takiron Shield Co., Ltd.) are prepared. Then, at the end of the length direction of one substrate, a curable composition is applied over the entire width of the plate with a length of 5 mm and the thickness after curing is 1 mm. Then, the end of the length direction of another substrate is superimposed on the coated curable composition, and in this state, it is placed under an environment of 25 ° C and 50% RH for 168 hours to cure the curable composition and obtain a measurement sample. The measurement sample is formed by overlapping two PET plates with a length of 5 mm over the entire width, and bonding the PET plates to each other with a cured product of the curable composition (size: 25 mm × 5 mm, thickness 1 mm) in the overlapping portion. It has a width of 25 mm and a length of 195 mm. The obtained measurement sample was subjected to a tensile test in an environment of 25° C. and 50% RH, in which the sample was stretched in its longitudinal direction at a tensile speed of 10 mm / sec until it broke. The maximum load was defined as the adhesive strength.

[0244] A: 1.5MPa or more

[0245] B: 1.00 MPa or more and less than 1.5 MPa

[0246] C: less than 1.00MPa

[0247] [Thermal conductivity]

[0248] The thermal conductivity of the first and second parts of the curable composition was determined by measuring thermal resistance using a measuring apparatus in accordance with ASTM D5470-06.

[0249] Specifically, the curable composition having a larger thickness than that when measuring is configured in a manner covering the measuring die head on the heating element side, and then clamped with a radiator, is compressed to a thickness of 1.0 mm, 1.5 mm, and 2.0 mm to measure the thermal resistance under each thickness with a load of 30 psi. The thickness can be adjusted with a spacer. For these three thermal resistance values, a graph with a horizontal axis being thickness and a vertical axis being thermal resistance value is made, and an approximate straight line at three points is obtained by the least square method. Furthermore, the slope of the approximate straight line is thermal conductivity.

[0250] The thermal resistance was measured at 80° C. using LW-9389 manufactured by Long Win Science and Technology Corporation. The area of ​​the measurement die was set to 1 inch×1 inch.

[0251] [Viscosity]

[0252] For each sample of the first and second agents, a rheometer (for example, a rheometer "MCR-302e" manufactured by Antron Corporation) is used. The temperature of the sample is adjusted to 25°C using a Peltier plate, and a parallel plate of φ25 mm is used to place the sample. The sample is immediately measured while continuously changing the shear rate within the range of 0.0001 to 100 (1 / s). Regarding the viscosity value, the viscosity at a shear rate of 3.16 (1 / s) is used as the measured value. It should be noted that the viscosity of each sample is measured after the sample is placed and allowed to stand for 10 minutes, and evaluated according to the following evaluation criteria.

[0253] A: 50Pa·s or more

[0254] B: more than 50Pa·s and less than 300Pa·s

[0255] C: 300 Pa·s or more

[0256] [Process bonding strength]

[0257] As substrates, a 25 mm x 100 mm x 2 mm thick aluminum plate and a glass fiber-reinforced PET substrate were prepared instead of two PET sheets. These were then stacked with the curable composition interposed between them. The samples were then left in this state at 18°C ​​and 20% RH for one hour to allow the curable composition to initially cure. The same procedures as in the adhesion test were followed to obtain the test samples. The obtained test samples were then subjected to a tensile test in the same manner as in the adhesion test, where they were stretched in the longitudinal direction until they broke. The maximum load was taken as the process bond strength. The process bond strength was evaluated according to the following evaluation criteria.

[0258] A: 0.25MPa or above

[0259] B: 0.1MPa or more and less than 0.25MPa

[0260] C: 0.05 MPa or more and less than 0.1 MPa

[0261] D: less than 0.05MPa

[0262] [Compression load]

[0263] Place 2g of the curable composition prepared according to the recipe on an aluminum foil of size 50mm×50mm×12μm thick, wrap it with aluminum foil, and place it in a thermostatic bath at 35°C for 10 minutes to obtain a measurement sample. Then, without placing a sample, press the fixture on the measurement site in such a way that the load value becomes 3.6kg, and use the point 10mm away from this as the measurement starting point (zero point). Measure the compressive load of the measurement sample under the conditions shown below. The first and second doses are also measured in the same way.

[0264] Test speed: 60 mm / s

[0265] Clamp size: 3cmφ

[0266] Result reading: The displacement of 9.62 mm is used as the compression load value.

[0267] Test environment: 25°C, 50% RH

[0268] The obtained compressive load values ​​were evaluated according to the following four levels: The compressive load indicates the compressive load at the initial stage of curing, and a lower value tends to facilitate temporary bonding and extend the usable time.

[0269] AA: 500N or less

[0270] A: Below 800N

[0271] B: More than 800N and less than 1000N

[0272] C: More than 1000N and less than 1500N

[0273] D: more than 1500N

[0274] [Examples 1 to 8, Comparative Examples 1 to 3]

[0275] The components were mixed according to the formulation in Table 2 to prepare the first and second components. The adjusted first and second components were mixed at room temperature at the mass ratio (A:B) listed in Table 2 to obtain a curable composition. The resulting curable composition was subjected to physical property measurements and evaluation tests.

[0276] The resin components used in each of the Examples and Comparative Examples are shown in Table 1 below.

[0277]

[0278] In addition, components other than the resin component are as follows.

[0279] (Dispersant)

[0280] Polymer dispersants (copolymers containing acidic groups)

[0281] (Thermal conductive filler)

[0282] Aluminum hydroxide 1: average particle size 1 μm

[0283] Aluminum hydroxide 2: average particle size 10 μm

[0284] Aluminum hydroxide 3: average particle size 50 μm

[0285] Aluminum hydroxide 4: average particle size 105μm

[0286]

[0287] * The functional group content is the total number of epoxy groups in the epoxy resin and (meth)acryloyl groups in the acrylate compound per unit weight (g) for the first dose. It is the number of active hydrogen atoms in the amino group of the amine for the second dose.

[0288] *The equivalent ratio is the ratio of the number of active hydrogen atoms in the amino group contained in the amine in the curable composition obtained by mixing the first and second components at a mass ratio of 1:1, to the total number of epoxy groups and (meth)acryloyl groups contained in the epoxy resin and acrylate compound.

[0289] ※ In Table 2, the mixing ratios in the first and second doses are described so that the total is 100 parts by mass.

[0290] For each of the above embodiments, in the curable composition having epoxy resin, thermally conductive filler, amine compound and multifunctional acrylate compound, a specific amine compound of a specified amount is used, or a specified amount of water is contained. Therefore, after a short time after coating, the adhesive strength (process adhesive strength) of more than a certain value is obtained, and good rapid curing properties are possessed. On the other hand, the compressive load is low, and the service life can be extended. Moreover, as the curable composition of each embodiment, the viscosity before solidification can also be reduced.

[0291] In contrast, the curable compositions of the comparative examples contained an epoxy resin, a thermally conductive filler, an amine compound, and a polyfunctional acrylate compound, but did not use a specific amine compound or contain a specific amount of the specific amine compound. Therefore, the compressive load increased and the usable time could not be extended.

[0292] Explanation of symbols

[0293] 10 battery modules

[0294] 11, 21 battery cells

[0295] 12 Battery module housing (module housing)

[0296] 13, 23 gap material

[0297] 20 battery packs

[0298] 25 base member

Claims

1. A curable composition comprising an epoxy resin, a thermally conductive filler, an amine compound (X) containing two or more amino groups, and a multifunctional acrylate compound, The amine compound (X) has a viscosity of 20 Pa·s or less at 25° C. and 10 rpm as measured by an E-type viscometer, or has an oxyalkylene structure. The content of the amine compound (X) is 15% by mass or more and 55% by mass or less based on the total resin components. 2 . The curable composition according to claim 1 , wherein the content of the polyfunctional acrylate compound is 20% by mass or less based on the total resin components. 3 . The curable composition according to claim 1 , wherein the multifunctional acrylate compound has 3 or more functional groups. The curable composition according to claim 1 , wherein the polyfunctional acrylate compound has 6 or more functional groups. The curable composition according to claim 1 , wherein the viscosity at 25° C. measured by a rheometer is 300 Pa·s or less. The curable composition according to claim 1 , wherein the epoxy resin comprises a monofunctional epoxy resin. The curable composition according to claim 1 , wherein the amine compound (X) has an oxypropylene structure. 8 . The curable composition according to claim 1 , comprising 0.3% by mass or more and 2% by mass or less of water based on the total amount of the curable composition. 9 . The curable composition according to claim 1 , wherein the amine compound (X) comprises an amine compound having three or more amino groups.

10. The curable composition according to claim 1, comprising a first component and a second component, wherein the first component comprises the epoxy resin and the multifunctional acrylate compound and is filled in a first container, and the second component comprises the amine compound (X) and is filled in a second container. The curable composition according to claim 10 , wherein the difference between the viscosity (Pa·s) of the first component and the viscosity (Pa·s) of the second component at 25° C. measured by a rheometer is 150 Pa·s or less. 12 . The curable composition according to claim 10 , wherein a ratio of a functional group concentration (mol / g) of the second agent to a functional group concentration (mol / g) of the first agent is 1.3 or more and 2.6 or less.

13. A curable composition comprising an epoxy resin, a thermally conductive filler, an amine compound (X) containing two or more amino groups, a multifunctional acrylate compound, and water. The water content is 0.3% by mass or more and 2.0% by mass or less based on the total amount of the curable composition. 14 . A container kit filled with the curable composition according to claim 10 , comprising a first container filled with the first agent and a second container filled with the second agent.

15. A curable composition comprising an epoxy resin, a thermally conductive filler, an amine compound (X) containing two or more amino groups, and a multifunctional acrylate compound. The amine compound (X) has a viscosity of 20 Pa·s or less at 25° C. and 10 rpm as measured by an E-type viscometer, or has an oxyalkylene structure. The content of the amine compound (X) is 15% by mass or more and 70% by mass or less relative to the total resin component; The amine compound (X) includes an amine compound having two amino groups. 16 . A thermally conductive component comprising a cured product of the curable composition according to claim 1 . A battery module comprising the heat-conducting member according to claim 16 .

Images