Thermally conductive resin composition and thermally conductive member

Abstract

The thermally conductive resin composition contains an epoxy resin, an amine curing agent having three or more amino active hydrogen atoms, and a thermally conductive filler, and the equivalence ratio of the amino active hydrogen atoms to the epoxy group is greater than 1 and less than 2.7.

Description

Technical Field

[0001] The present invention relates to a thermally conductive resin composition and a thermally conductive member used in a battery module or the like. Background Art

[0002] Thermally conductive resin compositions are widely known as curable liquid compositions. They are used, for example, as thermally conductive components such as heat dissipation gap fillers, which are filled between a heating element and a heat dissipation element and then cured to form a solid, transferring heat generated by the heating element to the heat dissipation element.

[0003] In recent years, amidst the steady growth in electric vehicle production, demand for two-component, room-temperature-curing thermal gap fillers for lithium-ion batteries (LiBs) has increased. Specifically, thermal gap fillers are often used to secure components such as battery cells, battery modules, and battery packs, or to improve heat dissipation.

[0004] Urethane-based resin compositions have been commonly used as thermally conductive resin compositions for conventional LIBs. However, urethane-based resin compositions have high adhesive strength, which can lead to insufficient strength and deformation of cooling plates and other components during reprocessing, making the reprocessed components unusable.

[0005] In recent years, epoxy resins have also been studied as thermally conductive resin compositions for LIBs. Epoxy resin compositions, such as those disclosed in Patent Document 1, are known to contain a trifunctional or higher-functional epoxy resin without an aromatic skeleton, a liquid bifunctional or lower-functional epoxy resin, a curing agent, a silane compound without functional groups other than alkoxy groups, and a thermally conductive filler.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2022-116587 Summary of the Invention

[0009] Inventions must solve problems

[0010] However, the conventional epoxy resin-based thermally conductive resin composition disclosed in Patent Document 1 has not shown that the elongation of the thermally conductive resin composition can be increased while improving the adhesive strength.

[0011] Therefore, an object of the present invention is to provide a thermally conductive resin composition that can suppress a decrease in adhesive strength to a resin material such as PET and can be well elongated.

[0012] Means of solving problems

[0013] The present inventors have conducted intensive research and have discovered that, in a thermally conductive resin composition comprising an epoxy resin, an amine curing agent having three or more amino active hydrogen atoms, and a thermally conductive filler, by controlling the equivalent ratio of amino active hydrogen atoms to epoxy groups within a certain range, the above-mentioned problems can be solved. This has led to the completion of the following invention. Specifically, the present invention provides the following solutions [1] to

[18] .

[0014] [1] A thermally conductive resin composition comprising an epoxy resin, an amine curing agent having three or more amino active hydrogen groups, and a thermally conductive filler, wherein the equivalent ratio of the amino active hydrogen groups to the epoxy groups is greater than 1 and less than 2.7.

[0015] [2] The thermally conductive resin composition according to [1] above, wherein the amine curing agent has a primary amino group.

[0016] [3] The thermally conductive resin composition according to [2] above, wherein the amine curing agent has two or more primary amino groups in one molecule.

[0017] [4] The thermally conductive resin composition according to any one of [1] to [3] above, wherein the amine curing agent is an aliphatic amine.

[0018] [5] The thermally conductive resin composition according to any one of [1] to [4] above, wherein the epoxy resin contains an epoxy resin having an aromatic ring.

[0019] [6] The thermally conductive resin composition according to any one of [1] to [5], wherein the epoxy resin contains a multifunctional epoxy resin and a monofunctional epoxy resin.

[0020] [7] The thermally conductive resin composition according to any one of [1] to [6] above, wherein the filling rate of the thermally conductive filler is 50% by volume or more.

[0021] [8] The thermally conductive resin composition according to any one of [1] to [7] above, wherein the thermally conductive filler is at least one of aluminum oxide and aluminum hydroxide.

[0022] [9] The thermally conductive resin composition according to any one of [1] to [8] above, wherein the thermally conductive filler contains aluminum oxide and aluminum hydroxide.

[0023] The filling rate of the aluminum oxide is 4 volume % or more and 50 volume % or less, and the filling rate of the aluminum hydroxide is 25 volume % or more and 86 volume % or less.

[0024]

[10] The thermally conductive resin composition according to any one of [1] to [9] above, wherein the molecular weight of the epoxy resin is 1000 or less, and the molecular weight of the amine curing agent is 3000 or less.

[0025]

[11] The thermally conductive resin composition according to any one of [1] to

[10] above, wherein the equivalent ratio of amino active hydrogen to epoxy group is 1.05 or more.

[0026]

[12] The thermally conductive resin composition according to any one of [1] to

[11] above, wherein the equivalent ratio of amino active hydrogen to epoxy group is 1.12 or more and 2.63 or less.

[0027]

[13] The thermally conductive resin composition according to any one of [1] to

[12] above, wherein the equivalent ratio of amino active hydrogen to epoxy group is 1.78 or less.

[0028]

[14] The thermally conductive resin composition according to any one of [1] to

[13] above, comprising a first component containing an epoxy resin and filled in a first container, and a second component containing the amine curing agent and filled in a second container.

[0029]

[15] A container kit filled with the thermally conductive resin composition described in

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

[0030]

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

[14] .

[0031]

[17] A battery pack comprising the thermally conductive component described in

[16] .

[0032]

[18] Use of the thermally conductive resin composition described in any one of [1] to

[14] as at least one of a gap member between battery cells, a gap member between a battery cell and a module case, a gap member between a battery module and a battery pack case, and a gap member between a battery cell and a battery pack case.

[0033] Effects of the Invention

[0034] According to the present invention, there is provided a thermally conductive resin composition capable of excellent elongation while suppressing a decrease in adhesive strength to a resin material such as PET. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a schematic diagram showing a container kit according to one embodiment.

[0036] Figure 2 This is a schematic diagram showing a container kit according to another embodiment.

[0037] Figure 3It is a perspective view showing a typical structure of a battery module according to the present invention.

[0038] Figure 4 It is a perspective view showing a typical structure of a battery cell included in a battery module.

[0039] Figure 5 It is a perspective view showing a battery pack having a module-less structure. DETAILED DESCRIPTION

[0040] [Thermal conductive resin composition]

[0041] Hereinafter, the thermally conductive resin composition of the present invention will be described in detail.

[0042] The thermally conductive resin composition of the present invention comprises an epoxy resin, an amine curing agent having three or more amino active hydrogen groups, and a thermally conductive filler, wherein the equivalent ratio of the amino active hydrogen groups to the epoxy groups is greater than 1 and not more than 2.7.

[0043] The thermally conductive resin composition having the above structure has high adhesiveness to resin materials such as polyethylene terephthalate (PET) and also exhibits good elongation after curing.

[0044] <Equivalence ratio>

[0045] In the thermally conductive resin composition of the present invention, the equivalent ratio of amino active hydrogen to epoxy groups (hereinafter sometimes referred to as the equivalent ratio (NH / Ep)) is greater than 1 and less than 2.7. When the equivalent ratio (NH / Ep) is less than 1 or greater than 2.7, the adhesive strength to resin materials such as PET decreases, and the elongation of the thermally conductive resin composition decreases.

[0046] Although the principle is uncertain, it is speculated as follows. That is, when the equivalent ratio (NH / Ep) is less than 1, the epoxy groups that exist in excess react in large quantities relative to the amino groups whose crosslinking density is usually easy to increase, sometimes forming a composition that is difficult to elongate. In addition, since the polarity of the excess and residual epoxy groups is relatively low, the effect of improving the adhesion to resin substrates such as PET cannot be expected. In addition, sometimes active hydrogen (NH) does not remain after curing, or the residual amount of active hydrogen will also decrease. In this way, the adhesion to resin materials such as PET that do not have polar groups cannot be fully improved, or elongation cannot be fully ensured. In addition, when the equivalent ratio (NH / Ep) is greater than 2.7, the uncured components increase after curing, and the uncured components will hinder adhesion or reduce elongation.

[0047] For a typical epoxy resin and curing agent combination, from the perspective of achieving both adhesion to resin materials such as PET and elongation of the thermally conductive resin composition, the equivalent ratio (NH / Ep) is preferably 1.05 or greater, more preferably 1.1 or greater, more preferably 1.12 or greater, more preferably 1.2 or greater, and even more preferably 1.4 or greater. Furthermore, the equivalent ratio (NH / Ep) is preferably 2.7 or less, more preferably 2.63 or less, more preferably 2.6 or less, more preferably 2.5 or less, more preferably 2.4 or less, more preferably 2.2 or less, more preferably 2.18 or less, more preferably 1.8 or less, more preferably 1.6 or less, more preferably 1.5 or less, and even more preferably 1.47 or less.

[0048] Therefore, the equivalent ratio (NH / Ep) is preferably 1.05 to 2.7, more preferably 1.1 to 2.7, more preferably 1.12 to 2.63, more preferably 1.1 to 2.6, further preferably 1.1 to 2.5, further preferably 1.1 to 2.2, further preferably 1.12 to 2.18, further preferably 1.12 to 1.78, further preferably 1.12 to 1.47.

[0049] When the content of a trifunctional or higher-functional epoxy resin in a thermosetting resin composition is less than 10% by mass and the content of an amine curing agent having two primary amino groups and one or more reactive amino groups per molecule is 30% by mass or greater (hereinafter referred to as condition 1), from the perspective of achieving good adhesive strength, the equivalent ratio (NH / Ep) is preferably greater than 1, more preferably 1.05 or greater, more preferably 1.1 or greater, more preferably 1.12 or greater, more preferably 1.2 or greater, further preferably 1.4 or greater, and further preferably 1.5 or greater. Furthermore, under condition 1, from the perspective of achieving good adhesive strength, the equivalent ratio (NH / Ep) is preferably 2.7 or less, more preferably 2.63 or less, more preferably 2.6 or less, more preferably 2.5 or less, more preferably 2.4 or less, further preferably 2.2 or less, and further preferably 2.18 or less. Therefore, under condition 1, the equivalent ratio (NH / Ep) is preferably 1.05 to 2.7, more preferably 1.12 to 2.63, more preferably 1.2 to 2.6, more preferably 1.4 to 2.5, and even more preferably 1.5 to 2.18.

[0050] Here, the content of trifunctional or higher-functional epoxy resin being less than 10% by mass means that, among all epoxy resins contained in the thermally conductive resin composition, less than 10% by mass of the epoxy resin is trifunctional or higher-functional (i.e., having three or more epoxy groups in the molecule), and also includes the case where the content is 0% by mass, i.e., no trifunctional or higher-functional epoxy groups are contained.

[0051] Furthermore, the content of an amine curing agent having two primary amino groups and one or more reactive amino groups per molecule being 30% by mass or greater means that, of the total amine curing agent contained in the thermally conductive resin composition, 30% or more by mass of the amine curing agent has one or more reactive amino groups in addition to the two primary amino groups per molecule. Here, a reactive amino group is an amino group having an active hydrogen group, and may be either a primary or secondary amino group. The same interpretation shall apply to the following conditions 2 to 4, and even similar statements shall be interpreted in the same manner.

[0052] In a thermosetting resin composition, when the content of a trifunctional or higher epoxy resin is 10% by mass or more and the content of an amine curing agent having two primary amino groups and one or more reactive amino groups in one molecule is less than 30% by mass (hereinafter referred to as condition 2), from the perspective of achieving good adhesion, the equivalent ratio (NH / Ep) is preferably greater than 1, more preferably 1.05 or more, further preferably 1.1 or more, and further preferably 1.12 or more. In the case of condition 2, from the perspective of achieving good adhesion and elongation, the equivalent ratio (NH / Ep) is preferably 2 or less, more preferably 1.8 or less, more preferably 1.78 or less, further preferably 1.6 or less, and further preferably 1.47 or less. Therefore, in the case of condition 2, the equivalent ratio (NH / Ep) is preferably greater than 1 and 2 or less, more preferably 1.05 to 1.8, further preferably 1.1 to 1.8, further preferably 1.12 to 1.78, further preferably 1.12 to 1.6, and further preferably 1.12 to 1.47.

[0053] When the thermosetting resin composition contains a trifunctional or higher epoxy resin at a content of 10% by mass or greater and an amine curing agent having two primary amino groups and one or more reactive amino groups per molecule at a content of 30% by mass or greater (hereinafter referred to as condition 3), the equivalent ratio (NH / Ep) is preferably greater than 1, more preferably greater than 1.05, and even more preferably greater than 1.10. In condition 3, the equivalent ratio (NH / Ep) is preferably less than 2.70, more preferably less than 2.60, and even more preferably less than 2.50. Therefore, in condition 3, the equivalent ratio (NH / Ep) is preferably greater than 1 and less than 2.70, more preferably between 1.05 and 2.60, and even more preferably between 1.10 and 2.50.

[0054] When the content of a trifunctional or higher-functional epoxy resin in a thermosetting resin composition is less than 10% by mass and the content of an amine curing agent having two primary amino groups and one or more reactive amino groups per molecule is less than 30% by mass (hereinafter referred to as condition 4), the equivalent ratio (NH / Ep) is preferably greater than 1, more preferably greater than 1.05, and even more preferably greater than 1.10. In condition 4, the equivalent ratio (NH / Ep) is preferably less than 2.00, more preferably less than 1.80, and even more preferably less than 1.60. Therefore, in condition 4, the equivalent ratio (NH / Ep) is preferably greater than 1 and less than 2.00, more preferably between 1.05 and 1.80, and even more preferably between 1.10 and 1.60.

[0055] The equivalent ratio (NH / Ep) is synonymous with the ratio of the number of amino active hydrogen atoms to the number of epoxy groups contained in the thermally conductive resin composition, and can be determined by calculating the equivalent weight of epoxy groups and the equivalent weight of amino active hydrogen atoms as follows.

[0056] The epoxy equivalent can be obtained by dividing the content (g) of the epoxy resin in the thermally conductive resin composition by the epoxy equivalent (g / eq). However, when two or more epoxy resins are contained, the total value can be obtained by dividing the content (g) of each epoxy resin by the epoxy equivalent (g / eq).

[0057] The amino group active hydrogen equivalent can be obtained by dividing the amine content (g) in the thermally conductive resin composition by the amine 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 to obtain the equivalent.

[0058] In addition, the epoxy equivalent (g / eq) can be obtained by dividing the molecular weight of the epoxy resin by the number of epoxy groups per molecule. In addition, the active hydrogen equivalent (g / eq) can be obtained by dividing the molecular weight of the amine by the number of active hydrogens per molecule. The molecular weight, the number of epoxy groups, and the number of active hydrogens can be measured using a mass spectrometer (GC-MS or LC-MS). In addition, when only the molecular weight can be determined using a mass spectrometer, the number of epoxy groups per molecule and the number of active hydrogens can be determined using NMR (1H NMR, etc.). However, when the sample is a mixture, it is preferred to separate the components using GPC (gel permeation chromatography) or HPLC (high-speed liquid chromatography) and then measure the NMR.

[0059] If the structural formula of an epoxy resin is known, the molecular weight and the number of epoxy groups can be calculated from the structural formula. If the structural formula of an amine is known, the molecular weight and the number of active hydrogen atoms can be calculated from the structural formula.

[0060] In addition, regarding the number of active hydrogen atoms in an amine, NHR2 (secondary amino group) is 1, and NH2R (primary amino group) is 2 (wherein, in NHR2 and NH2R, R is a functional group other than active hydrogen atoms, i.e., a portion other than the NH or NH2 of the amine).

[0061] [Epoxy resin]

[0062] The thermally conductive resin composition of the present invention contains an epoxy resin. By including an epoxy resin, the adhesive strength of the thermally conductive resin composition can be easily adjusted to an appropriate range. The epoxy resin can be any compound having one or more epoxy groups. The epoxy resin can be a multifunctional epoxy resin having two or more epoxy groups, or a monofunctional epoxy resin having one epoxy group.

[0063] The thermally conductive resin composition of the present invention preferably contains at least a multifunctional epoxy resin. By containing a multifunctional epoxy resin, the thermally conductive resin composition can appropriately form crosslinks, thereby easily improving the adhesive strength.

[0064] In addition to containing a multifunctional epoxy resin, the thermally conductive resin composition more preferably further contains a monofunctional epoxy resin. By further containing a monofunctional epoxy resin, the thermally conductive resin composition can prevent the crosslinking density after curing from being too high, and the elongation can be easily improved. In addition, by using a monofunctional epoxy resin, it is easy to reduce the viscosity of the thermally conductive resin composition before curing. In addition, by using a monofunctional epoxy resin, if the equivalent ratio (NH / Ep) is adjusted to the desired range, the mass ratio of the epoxy resin to the amine curing agent can also be 1:1 or approximately 1:1. Therefore, in the two-liquid curing type, the mixing ratio of the first agent and the second agent can also be 1:1 or approximately 1:1.

[0065] However, when the crosslinking density is controlled by other means, such as using a curing agent with a small number of active hydrogen atoms per molecule (eg, diamines having two primary amino groups), the elongation can be easily improved even without using a monofunctional epoxy resin.

[0066] 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, and even more preferably 25 / 75 or more and 50 / 50 or less.

[0067] Examples of multifunctional epoxy resins include bifunctional and trifunctional ones, with bifunctional epoxy resins being preferred. A combination of bifunctional and trifunctional epoxy resins is also preferred. Furthermore, when trifunctional epoxy resins are used, the reactive sites of the epoxy groups are more likely to form crosslinks, which can improve the bonding strength.

[0068] When the epoxy resin contains a trifunctional epoxy resin, the content of the trifunctional epoxy resin is preferably 10% by mass or more, more preferably 30% by mass or more, relative to the total epoxy resin contained in the thermally conductive resin composition. Alternatively, the content may be 100% by mass or less, but is preferably 70% by mass or less, more preferably 50% by mass or less.

[0069] Specific examples of the multifunctional epoxy resins are not limited to these, and include epoxy resins having aromatic rings such as phenol novolac-type epoxy resins, resorcinol-type 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.

[0070] 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 also be mentioned.

[0071] Other examples include aliphatic epoxy resins such as alkanediol diglycidyl ethers such as butanediol diglycidyl ether and neopentyl glycol diglycidyl ether. Examples of aliphatic epoxy resins include, in addition to these, alkyl polyol polyglycidyl ethers other than alkanediol diglycidyl ethers such as trimethylolpropane polyglycidyl ether. Examples include polyalkylene glycol diglycidyl ethers such as poly-1,4-butylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, and polypropylene glycol diglycidyl ether.

[0072] Furthermore, hydrogenated products or modified products of the above-exemplified epoxy resins can also be used as the epoxy resin.

[0073] 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.

[0074] Examples of the resorcinol-type epoxy resin include resorcinol diglycidyl ether.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] Examples of the epoxy resin having a xanthene skeleton include 1,3,4,5,6,8-hexamethyl-2,7-bis-glycidylmethoxy-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 in one molecule.

[0079] Examples of the epoxy resin having a pyrene skeleton include resins having one or more pyrene skeletons and two or more epoxy groups or glycidyl groups in one molecule.

[0080] 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.

[0081] Among the polyfunctional epoxy resins mentioned above, epoxy resins having an aromatic ring are preferred from the viewpoint of improving adhesive strength and mechanical strength. Among them, epoxy resins having a phenyl group are more preferred, and epoxy resins having a bisphenol skeleton, i.e., bisphenol-type epoxy resins, are even more preferred. Furthermore, aliphatic epoxy resins such as alkyl polyol polyglycidyl ethers are also preferred, and the combined use of an aliphatic epoxy resin and an epoxy resin having an aromatic ring is also preferred.

[0082] The multifunctional epoxy resin may be used alone or in combination of two or more.

[0083] 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. More preferred monofunctional epoxy resins having an aromatic ring are epoxy resins having a phenyl group.

[0084] Furthermore, monofunctional epoxy resins are preferably aliphatic monofunctional epoxy resins due to the high safety of the raw materials. Specific examples include glycidyl ethers of aliphatic alcohols. The aliphatic alcohol may have a branched or linear structure, but a linear structure is preferred for improved elongation. For example, the aliphatic alcohol may have 4 to 24 carbon atoms, but preferably has 10 to 20 carbon atoms for improved elongation. Furthermore, a saturated aliphatic alcohol is preferred for improved elongation. Specific glycidyl ethers of aliphatic alcohols include butyl glycidyl ether, decyl glycidyl ether, lauryl glycidyl ether, myristyl glycidyl ether, hexadecyl glycidyl ether, and stearyl glycidyl ether. In addition to the aforementioned monofunctional epoxy resins, examples include monofunctional epoxy resins that do not have an ether group but do have a glycidyl group, such as 1,2-butylene oxide and propylene oxide.

[0085] As the monofunctional epoxy resin, from the viewpoint of achieving good elongation, an aliphatic monofunctional epoxy resin is preferably used, and among them, glycidyl ether of an aliphatic alcohol is preferably used.

[0086] The monofunctional epoxy resin may be used alone or in combination of two or more.

[0087] The epoxy resin preferably contains an aromatic ring, particularly a phenyl group. Epoxy resins containing aromatic rings, such as phenyl groups, can be either monofunctional or multifunctional. Aromatic rings, particularly phenyl groups, form a stacked structure after curing, making it easy for the epoxy resin to form a pseudo-crosslinked structure in the cured product. This easily increases mechanical strength and adhesive strength. The epoxy resin preferably contains a multifunctional epoxy resin, and the multifunctional epoxy resin preferably contains an aromatic ring, particularly a phenyl group.

[0088] The epoxy resin may have a molecular weight of, for example, 2000 or less, preferably 1000 or less, and more preferably 500 or less. By using a resin having a molecular weight of a certain value or less, the viscosity of the thermally conductive resin composition can be reduced, and the thermally conductive filler can also be highly filled. The molecular weight of the epoxy resin is, for example, 100 or more, preferably 150 or more, more preferably 200 or more, and further 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 higher than necessary, and good elongation can be easily achieved. In addition, it is better that the epoxy resin is liquid at room temperature (25°C).

[0089] 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. It is preferably 100 g / eq or more, more preferably 125 g / eq or more, and even more preferably 140 g / eq or less.

[0090] [Amine curing agent]

[0091] The thermally conductive resin composition of the present invention contains an amine curing agent (hereinafter sometimes referred to as the "amine curing agent") having three or more amino active hydrogen atoms. The amine curing agent is a component that reacts with the epoxy resin to cure the thermally conductive resin composition. The inclusion of an amine curing agent facilitates adjustment of the thermally conductive resin composition to a practical curing rate at room temperature. Furthermore, the presence of three or more amino active hydrogen atoms in the amine curing agent facilitates crosslinking. Furthermore, since the active hydrogen atoms are likely to remain, it is easy to maintain a certain level of adhesion and elongation of the thermally conductive resin composition to the resin material.

[0092] The number of amino active hydrogen groups in one molecule of the amine curing agent is preferably 3 or more, preferably 4 or more, more preferably 5 or more, and even more preferably 6 or more. Furthermore, the number of amino active hydrogen groups in one molecule of the amine curing agent is not particularly limited, but is, for example, preferably 12 or less, preferably 10 or less, and more preferably 8 or less.

[0093] The amino groups in the amine curing agent may be primary or secondary, but from the perspective of reactivity and curing speed, amine curing agents preferably have primary amino groups. Amine curing agents preferably have two or more primary amino groups per molecule, more preferably two or more primary amino groups and one or more reactive amino groups, and even more preferably three or more primary amino groups per molecule. Amine curing agents having two or more primary amino groups, particularly two primary amino groups and two or more reactive amino groups, and particularly three or more primary amino groups, can increase the curing speed and form a suitable crosslinked structure in the cured product.

[0094] Furthermore, since an amine curing agent has two primary amino groups and one or more reactive amino groups (particularly three or more primary amino groups) per molecule, it readily forms a branched structure and crosslinks even when the equivalent ratio (NH / Ep) is increased. The number of primary amino groups per molecule of an amine curing agent is, for example, six or fewer, preferably five or fewer, and more preferably four or fewer. To suppress excessive crosslinking while maintaining a moderate curing speed, the number of primary amino groups is preferably two or three.

[0095] When a curing agent having three or more primary amino groups is used, the content of the amine curing agent having three or more primary amino groups is preferably 30% by mass or more, more preferably 50% by mass or more, relative to the total amines contained in the thermally conductive resin composition, and may be 100% by mass or less.

[0096] In addition, in the present invention, from the perspective of achieving a moderate curing speed while forming an appropriate cross-linked structure and imparting appropriate elongation, it is preferred to use a trifunctional epoxy resin as the multifunctional epoxy resin (A), or to use an amine having three or more (particularly three) primary amino groups as the amine curing agent (B). Moreover, when a trifunctional epoxy resin is used as the multifunctional epoxy resin (A), from the perspective of achieving a moderate curing speed and cross-linking density, it is preferred to use an amine curing agent (B) having two amino groups per molecule. Similarly, when a bifunctional epoxy resin is used as the multifunctional epoxy resin (A), from the perspective of achieving a moderate curing speed and cross-linking density, it is preferred to use an amine curing agent (B) having three or more (particularly three) amino groups per molecule.

[0097] As the amine curing agent, polyamines such as diamines and triamines can be listed. In addition, the amine curing agent can be an aliphatic amine or an amine containing an aromatic ring. Specific examples of aliphatic amines include, but are not limited to, polyoxyethylenediamine, poly(oxyethylene / oxypropylene)diamine, polyoxypropylenediamine, poly(oxybutylene / oxypropylene))diamine, polyethylene glycol bis(propylamine), trimethylolpropane poly(oxypropylene)triamine, glyceryl poly(oxypropylene)triamine and other polyoxyalkylene polyamines, 1,6-hexanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, Branched or linear alkyl diamines such as diamine, 1,14-tetradecane diamine, 1,16-hexadecane diamine, 1,18-octadecane diamine, 1,20-eicosane diamine, 2-methyl-1,5-diaminopentane, 2-methyl-1,8-octanediamine, 2-methyl-1,9-nonane diamine, and 2,7-dimethyl-1,8-octanediamine; and alicyclic polyamines such as 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, cyclohexane diamine, methylcyclohexane diamine, and isophorone diamine.

[0098] The aromatic ring-containing amines include, but are not limited to, aromatic amines in which the amino group is directly bonded to the aromatic ring, such as m-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, and 2,6-naphthalenediamine. Amines in which the amino group is not directly bonded to the aromatic ring, such as m-phenylenediamine, p-phenylenediamine, and the reaction product of m-phenylenediamine and styrene, may also be used.

[0099] In addition, as the amine curing agent, polyamidoamine, esteramine, etc. can be mentioned.

[0100] As the amine curing agent, among the above, aliphatic amines are preferred from the viewpoint of accelerating the curing rate, and polyoxyalkylene polyamines and branched or linear alkylenediamines are more preferred. From the viewpoint of further improving the elongation, polyoxyalkylene polyamines are even more preferred.

[0101] The amine curing agent may be used alone or in combination of two or more.

[0102] The molecular weight of the amine curing agent is not particularly limited, but is preferably 5000 or less, preferably 3000 or less, more preferably 1000 or less, and even more preferably 600 or less. By using an amine curing agent having a molecular weight below a certain value, the viscosity of the thermally conductive resin composition can be reduced, and the thermally conductive filler can be highly filled.

[0103] The molecular weight of the amine curing agent can be, for example, 100 or greater, preferably 110 or greater, more preferably 200 or greater, and even more preferably 300 or greater. By setting the molecular weight of the amine curing agent above a certain value, the crosslinking density can be prevented from becoming excessive, thereby facilitating improved elongation and adhesion. The amine curing agent should preferably be liquid at room temperature (25°C).

[0104] The molecular weight of the amine curing agent or the epoxy resin can be measured, for example, using a mass spectrometer (GC-MS or LC-MS).

[0105] The active hydrogen equivalent of the amine curing agent 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, and is, for example, 1000 g / eq or less, preferably 600 g / eq or less, more preferably 300 g / eq or less.

[0106] At least one of the amine curing agent and the epoxy resin preferably has a phenyl group. When at least one of the amine curing agent and the epoxy resin has a phenyl group, a pseudo-crosslinked structure is formed, which tends to improve the mechanical strength and adhesive strength of the thermally conductive resin composition.

[0107] The total amount (filling rate) of the amine curing agent and the epoxy resin relative to the volume of the thermally conductive resin composition as a whole is preferably 8% by volume or more and 49% by volume or less. If it is above the above lower limit, the thermally conductive filler can be appropriately dispersed in the thermally conductive resin composition. In addition, it is also possible to prevent the viscosity of the thermally conductive resin composition from becoming higher than necessary. In addition, by being below the above upper limit, it is easy to contain a certain amount of thermally conductive filler in the thermally conductive resin composition. The total amount of the amine curing agent and the epoxy resin in the thermally conductive resin composition is more preferably 12% by volume or more and 29% by volume or less, more preferably 14% by volume or more and 24.5% by volume or less, and more preferably 15% by volume or more and 23.5% by volume or less.

[0108] In addition, the thermally conductive resin composition of the present invention may also contain amines having two or less amino active hydrogens (hereinafter also referred to as other amines) as long as it can exert the effects of the present invention. As other amines, monoamines having only one primary amino group, diamines having two secondary amino groups, etc. can be listed. Specifically, the following can be listed but are not limited to these: methoxypoly(oxyethylene / oxypropylene)-2-propylamine, diglycolamine, N-methylethanolamine, 3-butoxypropanolamine, ethylene glycolamine, propylene glycolamine, polyamideamine, esteramine, etc. As esteramines, 1,5-bis[1,2-bis(ethoxycarbonyl)ethylamino]-2-methylpentane can be listed, and as commercially available products, "E-6347" manufactured by Dadu Industry can be listed.

[0109] From the viewpoint of reducing the viscosity of the thermally conductive resin composition, other amines may be in a liquid state at 25°C.

[0110] The other amines may be used alone or in combination of two or more.

[0111] The amount of other amines is preferably smaller than that of the amine curing agent having three or more amino active hydrogen atoms. Specifically, the ratio of the number of active hydrogen atoms of the other amines to the number of active hydrogen atoms of the amine curing agent contained in the thermoplastic resin composition (other amines / amine curing agent) is preferably smaller. Specifically, for example, the ratio is 0.8 or less, preferably 0.5 or less, more preferably 0.3 or less, and even more preferably 0.1 or less. The lower limit of the ratio (other amines / amine curing agent) is not particularly limited and is 0.

[0112] The number of active hydrogen atoms in the amine curing agent referred to here refers to the number of active hydrogen atoms in the amine curing agent contained in the entire thermoplastic resin composition. The same applies to the number of active hydrogen atoms in other amines.

[0113] [Thermal conductive filler]

[0114] The thermally conductive resin composition of the present invention contains a thermally conductive filler. When the thermally conductive resin composition contains a thermally conductive filler, the thermal conductivity of the thermally conductive resin composition is improved.

[0115] 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 shape of the thermally conductive filler include spherical and amorphous powders.

[0116] Among the thermally conductive fillers, examples of metals include aluminum, copper, nickel, and the like; examples of metal oxides include aluminum oxide represented by aluminum oxide, magnesium oxide, zinc oxide, and the like; and examples of metal nitrides include aluminum nitride and the like. Examples of metal hydroxides include aluminum hydroxide. In addition, examples of carbon materials include spherical graphite and the like. Examples of oxides, nitrides, and carbides other than metals include quartz, boron nitride, and silicon carbide. Among these, from the viewpoint of ensuring insulation properties, metal oxides, metal nitrides, metal hydroxides, carbon materials, and oxides, nitrides, and carbides other than metals are preferred, with metal oxides and metal hydroxides being more preferred.

[0117] Among the above, aluminum oxide is preferred from the viewpoint of improving the heat dissipation of the thermally conductive component. When it is desired to improve flame retardancy or reduce the specific gravity of the inorganic filler to reduce the weight of the thermally conductive resin composition, aluminum hydroxide is preferred.

[0118] As the thermally conductive filler, the above-mentioned fillers may be used alone or in combination of two or more.

[0119] The average particle size of the thermally conductive filler is preferably 0.1 μm or more and 200 μm or less, more preferably 0.5 μm or more and 150 μm or less, and even more preferably 1 μm or more and 110 μm or less.

[0120] The thermally conductive filler preferably uses a small thermally conductive filler with an average particle size of 0.1 μm to 5 μm and a large thermally conductive filler with an average particle size of 5 μm to 200 μm in combination. Using thermally conductive fillers with different average particle sizes can increase the filling rate.

[0121] 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 arbitrary 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.

[0122] The content (filling ratio) of the thermally conductive filler in the thermally conductive resin composition is preferably 50% by volume or more relative to the total volume of the thermally conductive resin composition. If this content is above the lower limit, a certain degree of thermal conductivity can be imparted to the thermally conductive resin composition. From the perspective of achieving even better thermal conductivity, the content is more preferably 70% by volume or more, further preferably 72% by volume or more, and even more preferably 75% by volume or more.

[0123] Furthermore, the content of the thermally conductive filler in the thermally conductive resin composition is preferably 90% by volume or less relative to the total volume of the thermally conductive resin composition. By setting the content of the thermally conductive filler below the aforementioned upper limit, the thermally conductive filler can be properly dispersed in the thermally conductive resin composition, and the viscosity of the thermally conductive resin composition can be prevented from becoming unnecessarily high. Furthermore, it is easier to achieve good elongation of the thermally conductive resin composition. From these viewpoints, the content of the thermally conductive filler in the thermally conductive resin composition is more preferably 85% by volume or less, more preferably 80% by volume or less, and even more preferably 79% by volume or less.

[0124] The content of the thermally conductive filler in the thermally conductive resin composition is not particularly limited when expressed in parts by mass, but is preferably 300 parts by mass or more and 3000 parts by mass or less, more preferably 500 parts by mass or more and 2000 parts by mass or less, even more preferably 600 parts by mass or more and 1800 parts by mass or less, and even more preferably 800 parts by mass or more and 1500 parts by mass or less, relative to 100 parts by mass of the total of the epoxy resin and the amine curing agent.

[0125] In addition, in order to suppress the specific gravity of the composition and achieve lightweight while achieving high thermal conductivity, it is preferred to use aluminum oxide and aluminum hydroxide together. At this time, the filling rate of aluminum oxide is, for example, more than 4 volume % and less than 60 volume % relative to the volume of the thermally conductive resin composition as a whole, preferably more than 4 volume % and less than 50 volume %. When the filling rate of aluminum oxide is below the above-mentioned upper limit, the specific gravity of the thermally conductive resin composition becomes smaller and becomes lightweight. On the other hand, if it is set to more than the above-mentioned lower limit, it is easy to ensure a certain thermal conductivity. From these viewpoints, the above-mentioned filling rate of aluminum oxide is more preferably more than 6 volume % and less than 40 volume %, and further preferably more than 10 volume % and less than 30 volume %.

[0126] The aluminum hydroxide filling rate is preferably, for example, 10% by volume or more and 86% by volume or less relative to the volume of the thermally conductive resin composition as a whole, preferably 25% by volume or more and 86% by volume or less. If the amount of aluminum hydroxide is below the above lower limit, while improving thermal conductivity, the specific gravity of the thermally conductive resin composition becomes smaller and becomes lightweight. On the other hand, if it is set to below the above upper limit, it is easy to contain more than a certain amount of aluminum oxide, and it is easy to ensure a certain thermal conductivity. From these viewpoints, the above-mentioned filling rate of aluminum hydroxide is more preferably 35% by volume or more and 75% by volume or less, and further preferably 45% by volume or more and 65% by volume or less.

[0127] In addition, the filling rate of aluminum hydroxide can be, for example, greater than 0.25 and less than 15, but is preferably higher than the filling rate of aluminum oxide. The ratio of the filling rate of aluminum hydroxide to the filling rate of aluminum oxide is preferably greater than 1 and less than 15, more preferably greater than 1.05 and less than 10, and further preferably greater than 1.5 and less than 5.

[0128] (Dispersant)

[0129] The thermally conductive resin composition of the present invention may contain a dispersant. Examples of the dispersant include polymeric dispersants. Examples of polymeric dispersants include polymer compounds having functional groups. Examples of polymeric compounds include acrylic, vinyl, polyester, polyurethane, polyether, epoxy, polystyrene, amino, and siloxane compounds. Functional groups include carboxyl, phosphoric, sulfonic, carboxylate, phosphoric, sulfonic, hydroxyl, amino, quaternary ammonium, and amide groups. Dispersants other than polymeric dispersants may be used, such as alkoxysilane compounds.

[0130] The content of the dispersant in the thermally conductive resin composition is preferably 0.1 to 20 parts by mass, more preferably 0.2 to 10 parts by mass, and even more preferably 0.4 to 5 parts by mass, relative to 100 parts by mass of the total of the epoxy resin and the amine curing agent.

[0131] (Thinner)

[0132] The thermally conductive resin composition of the present invention may contain a diluent. The diluent may be liquid at room temperature. The diluent is a non-reactive compound that does not have a functional group reactive with an amine, such as an epoxy resin or an amine curing agent. The use of a diluent can reduce the viscosity of the thermally conductive resin composition.

[0133] Examples of the diluent include fatty acid esters, for example, esters of fatty acids and monovalent aliphatic alcohols such as hexadecyl 2-ethylhexanoate, methyl laurate, isopropyl myristate, isopropyl palmitate, 2-ethylhexyl palmitate, octyldodecyl myristate, methyl stearate, butyl stearate, 2-ethylhexyl stearate, isotridecyl stearate, methyl octanoate, methyl myristate, methyl oleate, isobutyl oleate, octyl oleate, lauryl oleate, myristyl myristate, 2-ethylhexyl oleate, decyl oleate, and isobutyl oleate. Among them, hexadecyl 2-ethylhexanoate is preferred.

[0134] The content of the diluent is not particularly limited, but is preferably 0.1 to 10 parts by mass, more preferably 0.2 to 5 parts by mass, and even more preferably 0.3 to 3 parts by mass, relative to 100 parts by mass of the total of the epoxy resin and the amine curing agent.

[0135] (Other additives)

[0136] The thermally conductive resin composition of the present invention may contain additives other than those mentioned above. Examples of such additives include a curing catalyst that promotes the reaction between the main agent and the curing agent, a reaction rate controller that inhibits the reaction between the main agent and the curing agent, a thixotropy-imparting agent, a flame retardant, an antioxidant, and a colorant.

[0137] Viscosity

[0138] The viscosity of the thermally conductive resin composition of the present invention measured at 10 rpm at 25°C is preferably 500 Pa·s or less. By making the viscosity of the thermally conductive resin composition 500 Pa·s or less, the thermally conductive resin composition can be easily applied to the adherend, for example, the time for the application process using a dispenser can be shortened. In addition, the time for the process of assembling the battery module or battery cell from above the applied thermally conductive resin composition can be shortened, and the workability is improved. In addition, it is also easy to fill the narrow gap with the thermally conductive resin composition. The above viscosity is more preferably 300 Pa·s or less, and further preferably 250 Pa·s or less. In addition, the above viscosity can be, for example, 10 Pa·s or more, but from the viewpoint of filling a certain amount of thermally conductive filler and making it difficult to cause leakage, it is preferably 20 Pa·s or more, and more preferably 40 Pa·s or more.

[0139] The viscosity of the thermally conductive resin composition is the viscosity before curing, and in the case of a two-component type, for example, it can be measured immediately after mixing the first component and the second component.

[0140] Adhesion strength

[0141] The thermally conductive resin composition of the present invention has a structure as described above, and its adhesion to resin materials such as PET is increased. In particular, by optimizing the equivalent ratio (NH / Ep), the adhesion can be increased. In addition, the optimal value of the equivalent ratio (NH / Ep) varies depending on the type of epoxy resin and amine curing agent used. As an alternative, amine curing agents can be those that have two primary amino groups and one or more reactive amino groups in one molecule. On the other hand, epoxy resins with three or more functional groups are not used, and even if used, they are only used in small amounts. In this case, when the equivalent ratio (NH / Ep) increases, the residual NH groups after the reaction increase, and due to the influence of the polarity of the NH group, the adhesion is improved, and the crosslinking density after the reaction with the amine curing agent also increases. Therefore, the optimal value of the equivalent ratio for improving the adhesion is relatively large.

[0142] Alternatively, a substance having two primary amino groups and one or more reactive amino groups per molecule may not be used, or even if used, it may be used in small amounts, while a trifunctional or higher epoxy resin may be used. In this case, increasing the equivalent ratio (NH / Ep) increases the number of residual NH groups after the reaction, which improves adhesion due to the polarity of the NH groups. However, the amount of epoxy resin forming a crosslinked structure decreases, and the degree of crosslinking after the reaction does not increase. Consequently, the optimal equivalent ratio for improving adhesion becomes relatively low.

[0143] The adhesive strength of the thermally conductive resin composition to PET is preferably, for example, 0.70 MPa or greater, preferably 1 MPa or greater, more preferably 1.2 MPa or greater, and even more preferably 1.4 MPa or greater. From the perspective of reworkability, the adhesive strength of the thermally conductive resin composition to PET is preferably below a certain level, preferably 3.5 MPa or less, more preferably 3.0 MPa or less, and even more preferably 2.5 MPa or less.

[0144] The thermally conductive resin composition of the present invention preferably has an elongation after curing of, for example, 0.40 mm or greater, preferably 0.58 mm or greater, more preferably 0.70 mm or greater, and even more preferably 0.75 mm or greater. While there is no particular limitation on the elongation, from the perspective of imparting a certain level of adhesive strength, it is preferably 2 mm or less, more preferably 1.4 mm or less, and even more preferably 1 mm or less.

[0145] The adhesion and elongation of the thermally conductive resin composition can be determined by measuring the shear adhesion and shear elongation according to DIN EN 1465. In addition, the breaking strength is regarded as the "adhesion", and the elongation at break is regarded as the "elongation". In addition, two PET films mixed with glass fibers of 25 mm × 100 mm and a thickness of 2.0 mm are prepared as substrates, and the ends of the two films are bonded together by curing the thermally conductive resin composition coated in a manner of 25 mm × 15 mm and having a thickness of 2 mm after curing to obtain a measurement sample. The measurement is carried out at a tensile speed of 10 mm / min at 25°C. In addition, the curing of the thermally conductive resin composition can be carried out by curing the thermally conductive resin composition between the PET films. For example, in the case of a two-liquid type, the first agent and the second agent can be mixed and coated between the PET films, and then placed at room temperature (25°C) for 336 hours.

[0146] Thermal conductivity

[0147] The thermal conductivity of the cured product of the thermally conductive resin composition of the present invention is preferably 1.5 W / (m·K) or more, more preferably 2 W / (m·K) or more, and further preferably 2.5 W / (m·K) or more. The thermally conductive resin 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 from the battery cell can be effectively transferred to the module housing or battery pack via the cured product (thermal conductive component) of the thermally conductive resin composition, and the excessive temperature rise of the battery cell can be suppressed. The higher the above-mentioned thermal conductivity, the better, but in practical use, it is, for example, 25 W / (m·K) or less.

[0148] Thermal conductivity can be measured according to the method of ASTM D5470-06.

[0149] Specifically, in order to cover the measurement die head on the heating element side, the thermally conductive resin composition is configured to be thicker than the thickness during measurement, and then sandwiched with a radiator. Under a load of 30psi, the thickness of the adhesive is compressed to 1.0mm, 1.5mm, and 2.0mm, and the thermal resistance of each thickness is measured. The thickness can be adjusted with a gasket. For the values ​​of these three thermal resistances, a graph with the horizontal axis being the thickness and the vertical axis being the thermal resistance value is made, and an approximate straight line at three points is obtained by the least squares method. In addition, the slope of the approximate straight line is used as thermal conductivity.

[0150] (Supply form)

[0151] The thermally conductive resin composition of the present invention 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.

[0152] In the case of a two-component type, the thermally conductive resin composition can be cured by mixing and leaving it at room temperature (25°C), but can also be cured by heating after mixing. On the other hand, in the case of a one-component type, the thermally conductive resin composition can be cured by heating. When curing by heating, the thermally conductive resin composition can be heated to, for example, approximately 50 to 300°C.

[0153] In a two-component thermally conductive resin composition, the mass ratio of the first component to the second component (second component / first component) can be, for example, 0.25 to 4, preferably 1 or a value close to 1, specifically preferably 0.8 to 1.2, more preferably 0.9 to 1.1, and even 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 thermally conductive resin composition is facilitated.

[0154] In a two-component thermally conductive resin composition, both the first and second components are liquid at room temperature (25°C). Preferably, the first and second components have the same viscosity, or, even if they differ, the difference in viscosity is small. By ensuring that the first and second components have the same or similar viscosities, uniform mixing of the first and second components is facilitated.

[0155] Specifically, the viscosity difference between the first and second agents (Pa·s) is preferably 200 Pa·s or less, more preferably 150 Pa·s or less, and even more preferably 100 Pa·s or less. The viscosity difference may be 0 Pa·s or more.

[0156] The viscosity of the first and second agents is not particularly limited, but is preferably 10 Pa·s to 500 Pa·s, more preferably 20 Pa·s to 300 Pa·s, and even more preferably 40 Pa·s to 250 Pa·s.

[0157] The viscosities of the first and second agents mentioned here are measured using a rheometer (e.g., the "MCR-302e" manufactured by a company) with the sample temperature adjusted to 25°C using a Peltier plate and a 25 mm φ parallel plate. The sample is then set and allowed to stand for 10 minutes. The shear rate is then continuously varied within a shear rate range of 0.0001 to 100 1 / sec. The viscosity values ​​above are at a shear rate of 3.16 1 / sec.

[0158] A two-component thermally conductive resin composition may have a first component containing an epoxy resin and a second component containing an amine curing agent. In a two-component thermally conductive resin composition, the first component preferably contains an epoxy resin but does not contain an amine such as an amine curing agent. However, the first component may contain an amine as long as it does not react with the epoxy resin. On the other hand, the second component preferably contains an amine such as an amine curing agent but does not contain an epoxy resin. However, the second component may contain an epoxy resin as long as it does not react with the amine.

[0159] The thermally conductive filler is contained in at least one of the first and second components, but is preferably contained in both. Therefore, it is preferred that the first component contain an epoxy resin and a thermally conductive filler, and the second component contain an amine curing agent and a thermally conductive filler. Furthermore, it is more preferred that the first component contain no amines such as an amine curing agent, and the second component contain no epoxy resin. Therefore, it is even more preferred that the entire epoxy resin of the thermally conductive resin composition be contained in the first component, and the entire amine curing agent of the thermally conductive resin composition be contained in the second component.

[0160] As described above, the thermally conductive filler is preferably contained in both the first and second agents, but it is more preferred that the filling rates of the thermally conductive filler in the first and second agents are approximately the same. Specifically, the ratio of the filling rate of the thermally conductive filler in the second agent to the filling rate of the thermally conductive filler in the first agent is preferably 0.67 or more and 1.5 or less, more preferably 0.83 or more and 1.2 or less, and further preferably 0.91 or more and 1.1 or less. By making the filling rates of the thermally conductive filler in the first and second agents approximately the same, it is easy to reduce the viscosity difference between the first and second agents, and the mass ratio of the first and second agents is also easy to approach 1. In addition, the filling rate of the thermally conductive filler in the first agent refers to the volume ratio (volume %) of the filler relative to the total amount of the first agent. The same is true for the filling rate of the thermally conductive filler in the second agent.

[0161] In the two-component type, a dispersant, diluent, or other additives may be included in one or both of the first and second components as needed. For example, if a thermally conductive filler is included in both the first and second components, a dispersant may be included in both the first and second components.

[0162] When the thermally conductive resin composition is a two-component type, the first and second components are preferably filled into separate containers. Specifically, the first component can be filled into a first container, and the second component can be filled into a second container. The first and second containers can be separate or integrated. By integrating the first and second containers, it is easier to supply them to the customer as a container kit. In this specification, the first container filled with the first component and the second container filled with the second component are sometimes collectively referred to as a container kit.

[0163] As a container, a syringe or a liquid capsule etc. can be cited, but it is not limited thereto. For example, when filling into a syringe, a double liquid parallel type syringe is preferably used. The double liquid parallel type syringe 30 is as shown in FIG. Figure 1 As shown, a first syringe 31 constituting a first container and a second syringe 32 constituting a second container are arranged side by side and integrated. The first and second agents 35 and 36 filled in the syringes 31 and 32 can be discharged from the syringes and mixed using the syringes as dispensers.

[0164] In the case of using a liquid capsule, the container set comprises a first liquid capsule constituting a first container and a second liquid capsule constituting a second container, and these liquid capsules may also be integrated. Furthermore, the liquid capsule is typically attached to a syringe (e.g., a first syringe and a second syringe), and the first dose delivered from the first liquid capsule and the second dose delivered from the second liquid capsule can be dispensed and mixed from the respective discharge ports of the first and second syringes, using each syringe as a dispenser.

[0165] The mixing of the first agent and the second agent can be performed in a mixer such as a static mixer. For example, the static mixer 38 is connected to the discharge port 31A of the first syringe 31 and the discharge port 32A of the second syringe 32, and the first agent 35 and the second agent 36 discharged from the discharge ports 31A and 32A can be mixed within the mixer 38. The mixture (thermal conductive resin composition) obtained by mixing in the mixer 38 can be discharged from the discharge port 39 of the mixer 38.

[0166] In addition, when using a bucket, Figure 2 As shown, the container kit may include a first pail 41 constituting a first container and filled with a first agent 45, and a second pail 42 constituting a second container and filled with a second agent 46. Furthermore, each pail 41 or 42 includes, for example, a container body 43A or 44A having an opening, the first agent 45 or the second agent 46 being filled therewith, and a lid 43B or 44B for closing the opening of each container body 43A or 44B.

[0167] (Method for preparing thermally conductive resin composition)

[0168] When the thermally conductive resin composition of the present invention is a two-component type, the first and second components can be obtained by mixing the components constituting the first and second components, respectively. Similarly, in the case of a single-component type, the thermally conductive resin composition can be obtained by mixing the components constituting the thermally conductive resin composition. There are no particular limitations on the method of mixing the components. For example, the composition can be prepared by adding a thermally conductive filler to an epoxy resin, an amine curing agent, or both, and then adding additives such as a dispersant as needed, followed by stirring or kneading.

[0169] Alternatively, the thermally conductive filler may be surface-treated with a dispersant and then mixed with an epoxy resin, an amine curing agent, or both. By pre-treating the thermally conductive filler with a dispersant, the surface of the filler is pre-modified with the dispersant. The pre-modified thermally conductive filler can then be mixed with an epoxy resin, an amine curing agent, or both to prepare a thermally conductive resin composition, or a first or second agent of the thermally conductive resin composition.

[0170] The method for pre-treating the surface with a dispersant is not particularly limited and can be performed using known methods, such as wet treatment and dry treatment. In wet treatment, for example, a thermally conductive filler can be added to a treatment solution prepared by dispersing or dissolving the dispersant in a solvent, mixed, and then dried, heated, washed, etc., to cause the dispersant to bind or adhere to the surface of the thermally conductive filler. Dry treatment involves surface treatment without the use of a dispersion medium. Specifically, the dispersant is mixed with the thermally conductive filler, stirred using a mixer, etc., and then heated to cause the dispersant to bind or adhere to the surface of the thermally conductive filler.

[0171] [Thermal conductive parts]

[0172] The thermally conductive resin composition of the present invention can be used as a thermally conductive component. The thermally conductive resin composition of the present invention becomes a thermally conductive component by curing. The thermally conductive component of the present invention is a cured product of the thermally conductive resin composition, comprising a polymer matrix and a thermally conductive filler. The polymer matrix is ​​composed of an epoxy resin cured product obtained by curing an epoxy resin and an amine curing agent, and the thermally conductive filler is dispersed in the polymer matrix and retained in the polymer matrix. The thermally conductive component can be arranged between two components such as a heating element and a heat sink for use. Examples of the heating element include heat-generating electronic components such as batteries. Examples of the heat sink include cooling components such as housings, radiators, and cooling plates.

[0173] [use]

[0174] The thermally conductive resin composition and thermally conductive component of the present invention can be used in various applications, such as battery assemblies such as lithium-ion battery (LiB) assemblies, power electronics, electronic packaging, LEDs, solar cells, power transmission networks, and other electronic equipment applications. Among them, use in battery assemblies is preferred, and use in LiB assemblies is more preferred. Therefore, in a preferred embodiment of the present invention, a battery assembly having the above-described thermally conductive component is provided. Furthermore, battery assemblies such as LiB assemblies are particularly suitable for use in vehicles such as electric vehicles.

[0175] In battery module applications, the thermally conductive resin composition and thermally conductive component of the present invention are preferably used as gap members in battery modules. Furthermore, in one embodiment, the thermally conductive resin composition and thermally conductive component of the present invention are preferably used in battery modules, and more preferably as gap members in battery modules. The following describes an example of the thermally conductive component of the present invention being used in a battery module.

[0176] A battery module comprises a thermally conductive spacer, multiple battery cells, and a module housing that houses the cells. The spacer is located within the module housing. Spacers made of a thermally conductive material are placed between the battery cells and between the battery cells and the module housing, with the spacers being in close contact with the battery cells and the module housing. This spacer maintains the separation between the battery cells. Furthermore, the spacer between the battery cells and the module housing is in close contact with both, transferring heat generated by the battery cells to the module housing.

[0177] Figure 3 Indicates the specific structure of the battery module. Figure 4 Indicates the specific structure of each battery unit. Figure 3 As shown, a plurality of battery cells 11 are arranged inside the battery module 10. Each battery cell 11 is stacked and sealed in a flexible outer film, and the overall shape is a flat body with a thickness that is thinner than the height and width. Such a battery cell 11 can be Figure 4 As shown, the positive electrode 11a and the negative electrode 11b are exposed to the outside, and the central portion 11c of the flat surface can be formed to have a thicker wall than the crimped end portion 11d. In addition, each battery cell 11 is preferably covered with a resin material. By covering the surface of each battery cell 10 with a resin material, it is easy to ensure insulation. There are no particular restrictions on the resin material, and examples include polyester resins such as PET (polyethylene terephthalate), olefin resins such as polyimide resins and polypropylene resins, and polycarbonate resins, among which PET is more preferred.

[0178] like Figure 3 As shown, the battery cells 11 are arranged in such a manner that their offset planes are opposite to each other. Figure 3In the structure of FIG, the gap member 13 is not filled so as to cover the entirety of the plurality of battery cells 11 housed within the module case 12. The gap member 13 is filled so as to fill the gap existing in a portion (the bottom portion) of the interior of the module case 12. The gap member 13 is filled between the battery cells 11 and between the battery cells 11 and the module case 12, and is in close contact with the surfaces of the battery cells 11 and the inner surface of the module case 12 in these portions.

[0179] The spacers 13 inserted between the battery cells 11 adhere to the surfaces of both battery cells 11. However, due to the appropriate elasticity and flexibility of the spacers 13 themselves, even if external forces that might displace the spacing between the battery cells 11 are applied, the deformation caused by these forces can be mitigated. Therefore, the spacers 13 have the function of maintaining the separation between the battery cells 11.

[0180] The gap members 13 filling the gap between the battery cells 11 and the inner surface of the module case 12 are also tightly bonded to the surfaces of the battery cells 11 and the inner surface of the module case 12. As a result, heat generated inside the battery cells 11 is transferred via the gap members 13 bonded to the surfaces of the battery cells 11 to the inner surface of the module case 12, which is in close contact with the other surface of the gap members 13.

[0181] As mentioned above, the surfaces of battery cells 11 are sometimes covered with a resin material such as PET. However, the thermally conductive resin composition of the present invention has increased adhesion to resin materials such as PET. Therefore, spacers 13 can prevent separation between battery cells 11 and between battery cells 11 and module case 12.

[0182] The gap members 13 can be formed within the battery module 10 by applying a liquid thermally conductive resin composition using a conventional dispenser and then curing the liquid thermally conductive resin composition. Furthermore, the low viscosity of the thermally conductive resin composition of the present invention, as described above, improves workability during the formation of the gap members 13. Furthermore, because the gap members 13 have high adhesion and good elongation, they will not separate from adherends such as the battery cells 11 even over long periods of time, maintaining high thermal conductivity over time.

[0183] When forming the gap member 13, as described above, a two-component thermally conductive resin composition is preferably used. This type of composition is easy to store, and if mixed immediately before use, it is difficult to solidify during application using a dispenser, curing quickly after application. Application using a dispenser is also preferred because it allows the liquid thermally conductive resin composition to be filled relatively deep within the housing 12 of the battery module 10.

[0184] The gap member 13 covering the battery cell 11 preferably 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 cell 11 can be stably held. In addition, by fully covering the battery cell with a large heat generation, the heat dissipation efficiency is improved. On the other hand, by setting it to 40% or less, the heat generated by the battery cell 11 can be effectively dissipated, and the weight increase and deterioration of workability can also be prevented. In addition, in order to achieve good heat dissipation efficiency, it is preferred to cover the side of the battery cell 11 having the electrodes 11a and 11b with the gap member 13, and it is more preferred to cover the entire electrodes 11a and 11b with the gap member 13. As described above, the battery module 10 can dissipate the heat generated from the battery cell 11 to the module case 12 via the gap member 13.

[0185] The spacer 13 is also preferably used in battery packs that have multiple battery modules 10 inside. A battery pack generally includes multiple battery modules 10 and a battery pack housing that houses these modules 10. In such a battery pack, a spacer 13 can be provided between the battery modules 10 and the battery pack housing. This allows heat that has dissipated into the module housing 12 to be further dissipated into the battery pack housing, as described above, effectively dissipating the heat.

[0186] In addition, although the above description describes an example of a battery assembly that is a battery module or a battery pack having a battery module, it can also be applied to a battery assembly that does not have a battery module, for example, it is also preferably applied to a battery assembly having a cell to pack (CTP) structure.

[0187] Figure 5 This is a schematic diagram of a battery assembly with a module-free structure. The module-free battery assembly 20 comprises multiple battery cells 21 and a battery pack housing. The multiple battery cells 21 are bonded to a base member 25 constituting the battery pack housing via gap members 23 composed of a thermally conductive component (a cured product of a thermally conductive resin composition). The base member 25 may also comprise a cooling plate, etc. The base member 25, such as a cooling plate, may have irregularities on its surface, and the battery cells 21 may be bonded to the irregularities on the base member 25 via gap members 23.

[0188] The thermally conductive resin composition of the present invention has good thermal conductivity and high adhesive strength. Therefore, the gap member 23 composed of the cured thermally conductive resin composition can fix the battery cell 21 to the base component 25 with high adhesive strength while effectively dissipating the heat generated by the battery cell 21 to the base component 25.

[0189] The formation of the gap member 23 in the battery assembly 20 can be performed in the same manner as the formation of the gap member 13 in the battery module described above, for example, using a conventional dispenser. The reduced viscosity of the thermally conductive resin composition of the present invention also improves workability when forming the gap member 23.

[0190] While the above description illustrates an example where the surfaces of battery cells 11 and 21 are covered with a resin material, components other than battery cells, such as cooling plates and other base components, battery modules, module housings, and battery pack housings, may also be covered with or composed of a resin material. Even in such cases, the various components can be appropriately bonded to one another by using the thermally conductive resin composition of the present invention as a spacer disposed between the components.

[0191] Example

[0192] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0193] [Shear adhesion test]

[0194] According to DIN EN 1465, the adhesion of the thermally conductive resin composition to PET is measured by the following method. First, two PET films ("FR530 PET", manufactured by a Japanese company) with a width of 25 mm, a length of 100 mm and a thickness of 2 mm and mixed with glass fiber are prepared. Then, the thermally conductive resin composition is applied to the longitudinal end of one film over the entire film width with a length of 15 mm, so that the thickness after curing is 2 mm. Then, the longitudinal end of another film is overlapped on the coated thermally conductive resin composition, and in this state, it is placed under an environment of 25 ° C and 50% RH for 336 hours, thereby curing the thermally conductive resin composition to obtain a measurement sample. For the obtained measurement sample, a tensile test is performed by stretching the sample in the longitudinal direction at a tensile speed of 10 mm / sec until it breaks under an environment of 25 ° C and 50% RH, and the breaking strength is used as the "adhesion" (shear adhesion). In addition, the elongation at break is used as the "elongation" (shear elongation).

[0195] [Thermal conductivity]

[0196] The thermal conductivity of the first agent, the second agent, and the thermally conductive composition was determined by measuring thermal resistance using a measuring apparatus conforming to ASTM D5470-06.

[0197] Specifically, in a manner that covers the measuring die head as the heating element side, the first agent, the second agent or the thermally conductive composition is configured to be thicker than the thickness during measurement, and then it is sandwiched between the heat sink and compressed to a thickness of 1.0 mm, 1.5 mm, and 2.0 mm under a load of 30 psi to measure the thermal resistance of each thickness. The thickness is adjusted with a gasket. For the values ​​of these three thermal resistances, a curve graph is made with the horizontal axis being the thickness and the vertical axis being the thermal resistance value, and an approximate straight line at three points is obtained by the least squares method. The slope of the approximate straight line is then used as the thermal conductivity.

[0198] The thermal resistance was measured at 55° C. using LW-9389 manufactured by Long Win Science and Technology Corporation. The area of ​​the measurement die was 1 inch×1 inch.

[0199] [Viscosity]

[0200] A sample of the thermally conductive resin composition, immediately after preparation (immediately after mixing the first and second components), was measured using a rheometer (e.g., the MCR-302e, manufactured by a company). The sample temperature was adjusted to 25°C using a Peltier plate. The sample was set using a 25 mm φ parallel plate and immediately measured while continuously varying the shear rate within the range of 0.0001-100 1 / s. The viscosity was measured at a shear rate of 3.16 1 / s. The viscosity of the first and second components, before mixing, was similarly measured after the sample was set and allowed to stand for 10 minutes.

[0201] [Examples 1 to 17, Comparative Examples 1 to 6]

[0202] The components were mixed according to the formulations in Tables 1, 2, 3, and 4 to prepare the first and second compositions. The prepared first and second compositions were mixed at room temperature in the mass ratio (A:B) shown in Tables 1, 2, 3, and 4 to obtain thermally conductive resin compositions. The resulting thermally conductive resin compositions were evaluated.

[0203] The components used in each of the Examples and Comparative Examples are as follows.

[0204] (Epoxy resin)

[0205] Multifunctional epoxy resin 1: Bisphenol F type epoxy resin, trade name "jER806", manufactured by Mitsubishi Chemical Corporation, molecular weight 330, epoxy equivalent weight 165 g / eq, number of functional groups 2

[0206] Multifunctional epoxy resin 2: trimethylolpropane polyglycidyl ether, trade name "EX-321", molecular weight 325, epoxy equivalent weight 130g / eq, functional group number 2 to 3

[0207] Monofunctional epoxy resin: aliphatic glycidyl ether (aliphatic alcohol is C12-14), trade name "ML", manufactured by Yokkaichi Synthetic Co., Ltd., epoxy equivalent weight 282 g / eq, number of functional groups 1

[0208] (Amine curing agent)

[0209] Amine curing agent 1: trimethylolpropane poly(oxypropylene)triamine (trade name "T-403", manufactured by HUNTSMAN), molecular weight 440, active hydrogen equivalent weight 73.3 g / eq, number of amino active hydrogens = 6, functional group = 3×(-NH2)

[0210] Amine curing agent 2: polyoxypropylene diamine, trade name "D-400", manufactured by HUNTSMAN, molecular weight 430, active hydrogen equivalent 107.5 g / eq, number of amino active hydrogens = 4, functional group = 2×(-NH2)

[0211] Amine curing agent 3: poly(oxybutylene / oxypropylene)diamine, trade name "RT-1000", manufactured by HUNTSMAN, molecular weight 1000, active hydrogen equivalent 250 g / eq, number of amino active hydrogens = 4, functional group = 2×(-NH2)

[0212] (Dispersant)

[0213] Polymer dispersants (copolymers containing acidic groups)

[0214] (Non-reactive diluent)

[0215] Hexadecyl 2-ethylhexanoate, trade name "NIKKOL CIO", manufactured by Nikko Co., Ltd., molecular weight 369

[0216] (Thermal conductive filler)

[0217] Aluminum hydroxide 1: average particle size 1 μm

[0218] Aluminum hydroxide 2: average particle size 10 μm

[0219] Aluminum hydroxide 3: average particle size 90 μm

[0220] Alumina 1: average particle size 45 μm

[0221] Alumina 2: average particle size 5 μm

[0222] Alumina 3: average particle size 75 μm Table 1

[0223] Table 2

[0224] ※A=first dose, B=second dose

[0225] ※Specific gravity / unit indicates the specific gravity in the formula. Other values ​​indicate the units of each value.

[0226] In Examples 1 to 12 above, the thermally conductive resin compositions comprised an epoxy resin, an amine curing agent having three or more amino active hydrogen atoms, and a thermally conductive filler. By maintaining the equivalent ratio (NH / Ep) within a specified range, the compositions were able to suppress a decrease in adhesion to the resin material while also achieving good elongation. In contrast, in Comparative Examples 1 to 4, despite using the same epoxy resin and amine curing agent, the equivalent ratio (NH / Ep) was either less than 1 or greater than 2.7, failing to suppress a decrease in adhesion to the resin material while achieving good elongation compared to Examples 1 to 12.

[0227] Furthermore, in Examples 1-12, the amine curing agent has two primary amino groups and one or more reactive amino groups per molecule. Therefore, increasing the ratio of the amine curing agent to the epoxy resin to increase the equivalent ratio (NH / EP) leads to an increase in the crosslinking density after the reaction. Consequently, as the equivalent ratio (NH / EP ratio) increases, the number of residual amino groups after the reaction also increases. The polarity of the residual amino groups enhances the interaction with the adherend, and the increased crosslinking density after the reaction, leading to increased bulk strength, also tends to increase the adhesive strength. The highest adhesive strength is achieved at a relatively high equivalent ratio (NH / EP ratio). Table 3

[0228] Table 4

[0229] ※A=first dose, B=second dose

[0230] ※Specific gravity / unit indicates the specific gravity in the formula. Other values ​​indicate the units of each value.

[0231] The thermally conductive resin compositions of Examples 13 to 15 or Examples 16 to 17 above, each containing an epoxy resin, an amine curing agent having three or more amino active hydrogen atoms, and a thermally conductive filler, and having an equivalent ratio (NH / Ep) greater than 1 and less than 2.7, can achieve good elongation while suppressing a decrease in adhesion to the resin material, as compared to Comparative Example 5 or Comparative Example 6, which use the same epoxy resin and amine curing agent but have an equivalent ratio (NH / Ep) outside the range.

[0232] In Examples 13-15 or 16-17, the amine curing agent does not contain an amine curing agent containing two primary amino groups and one or more reactive amino groups per molecule. On the other hand, since the epoxy resin contains a trifunctional or higher epoxy resin, if the ratio of the amine curing agent to the epoxy resin is reduced to increase the equivalent ratio (NH / EP), the components that easily form crosslinks decrease. Therefore, as the equivalent ratio (NH / EP ratio) increases, the residual amino groups after the reaction also increase. Due to the polarity of the residual amino groups, the interaction with the adherend is enhanced, but the crosslink density after curing decreases. As a result, the adhesive strength is likely to decrease due to the decrease in bulk strength, but the adhesive strength is higher at a relatively low equivalent ratio (NH / EP ratio).

[0233] Description of the accompanying drawings

[0234] 10 battery modules

[0235] 11, 21 battery cells

[0236] 12 Battery module housing (module housing)

[0237] 13, 23 gap parts

[0238] 20 battery pack

[0239] 25 basic components

Claims

1. A thermally conductive resin composition comprising an epoxy resin, an amine curing agent having three or more amino active hydrogen groups, and a thermally conductive filler, wherein the equivalent ratio of the amino active hydrogen groups to the epoxy groups is greater than 1 and not more than 2.

7. 2 . The thermally conductive resin composition according to claim 1 , wherein the amine curing agent has a primary amino group. 3 . The thermally conductive resin composition according to claim 2 , wherein the amine curing agent has two or more primary amino groups in one molecule. The thermally conductive resin composition according to claim 1 , wherein the amine curing agent is an aliphatic amine. 5 . The thermally conductive resin composition according to claim 1 , wherein the epoxy resin comprises an epoxy resin having an aromatic ring. 6 . The thermally conductive resin composition according to claim 1 , wherein the epoxy resin comprises a polyfunctional epoxy resin and a monofunctional epoxy resin. 7 . The thermally conductive resin composition according to claim 1 , wherein the thermally conductive filler has a filling rate of 50% by volume or more. 8 . The thermally conductive resin composition according to claim 1 , wherein the thermally conductive filler is at least one of aluminum oxide and aluminum hydroxide.

9. The thermally conductive resin composition according to any one of claims 1 to 4, wherein the thermally conductive filler comprises aluminum oxide and aluminum hydroxide. The filling rate of the aluminum oxide is 4 volume % or more and 50 volume % or less, and the filling rate of the aluminum hydroxide is 25 volume % or more and 86 volume % or less. 10 . The thermally conductive resin composition according to claim 1 , wherein the molecular weight of the epoxy resin is 1,000 or less, and the molecular weight of the amine curing agent is 3,000 or less. 11 . The thermally conductive resin composition according to claim 1 , wherein the equivalent ratio of amino active hydrogen to epoxy group is 1.05 or more. 12 . The thermally conductive resin composition according to claim 1 , wherein an equivalent ratio of amino active hydrogen to epoxy group is 1.12 to 2.

63. 13 . The thermally conductive resin composition according to claim 1 , wherein the equivalent ratio of amino active hydrogen to epoxy group is 1.78 or less. 14 . The thermally conductive resin composition according to claim 1 , comprising a first component containing an epoxy resin and filled in a first container, and a second component containing the amine curing agent and filled in a second container. 15 . A container kit filled with the thermally conductive resin composition according to claim 14 , the container kit comprising a first container filled with the first agent and a second container filled with the second agent. 16 . A thermally conductive component comprising a cured product of the thermally conductive resin composition according to claim 1 .

17. A battery module comprising the thermally conductive member according to claim 16.

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