Curable thermoconductive adhesive and mode for supplying the same

Abstract

To provide a curable thermoconductive adhesive which has low viscosity and rapid curability while allowing a longer usable time.SOLUTION: There is provided a curable thermoconductive adhesive composed of a curable composition containing a curable binder and a thermoconductive filler, wherein a gelation point at which the storage modulus and loss modulus are equal when measured by rheometer at a constant temperature of 25°C is confirmed 5-60 minutes, inclusive, after starting the rheometer measurement, and the storage modulus at 25°C 60 minutes after starting the rheometer measurement is 9.0×105 Pa or more.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a curable thermally conductive adhesive and a thermally conductive member used for electronic device applications such as battery assemblies.

Background Art

[0002] Thermally conductive compositions are used, for example, to fill the space between a heat generating body and a heat dissipating body to transmit the heat generated by the heat generating body and dissipate it from the heat dissipating body. Thermally conductive compositions generally have curability and are often cured after being filled and used as cured products. Thermally conductive compositions play an important role in many electronic device applications such as battery assemblies such as lithium-ion batteries (LiB) assemblies for electric vehicles (EVs), power electronics, electronic packaging, LEDs, solar cells, and electrical grids.

[0003] For example, Patent Document 1 discloses a thermally conductive composition containing an epoxy resin, a polyamide composition containing a polyamide having a tertiary amide in the main chain and being amine-terminated, an amino-functional compound containing 2 to 20 carbon atoms, a polyfunctional (meth)acrylate, and an inorganic filler, which can be suitably used for electronic device applications such as battery assemblies.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, as the production volume of electric vehicles (EVs) continues to increase in the future, improving the room-temperature curability of thermally conductive compositions is one of the important issues in order to enhance their productivity. Assembly manufacturers place importance on the temporary adhesive force during the process, and it is required that after a certain period of time, the components can be moved within the process, that is, they can be temporarily fixed or placed vertically. When applying the temporary adhesion, it is necessary to follow the steps and depressions between the members. During the pot life, it is important that the resin can be easily spread on the substrate with a low load. For example, an adhesive that can be placed vertically in one hour and allows the resin to be easily spread on the substrate with a low load during the pot life is required. In addition, assembly manufacturers consider shortening the assembly time. For example, they assume that the components can be temporarily fixed after one hour, while the adhered components can be transported after 18 hours. Achieving both adhesion force development in a short time, within one day, and a long pot life is also an important issue when considering efficiency and workability.

[0006] In Patent Document 1, acrylate is added to enhance the rapid curability, and polyamide is used from the perspective of concerns about health hazards. Although polyamide has a low molecular weight, there is a problem that its viscosity increases due to its interaction. Therefore, although rapid curability can be achieved, a long pot life has not been achieved.

[0007] Therefore, an object of the present invention is to provide a curable thermally conductive adhesive that has a low viscosity and rapid curability while being able to extend the pot life.

Means for Solving the Problems

[0008] As a result of intensive studies, the inventors of the present invention have found that the above problems can be solved by adjusting so that the gelation point is confirmed within 5 minutes or more and 60 minutes or less from the start of the rheometer measurement, and the storage elastic modulus at 25°C after 60 minutes from the start of the rheometer measurement is a certain value or more. That is, the present invention provides the following [1] to

[13] .

[0009] [1] A curable thermally conductive adhesive comprising a curable composition containing a curable binder and a thermally conductive filler, wherein when measured with a rheometer at a constant temperature of 25°C, the gelation point at which the values of the storage elastic modulus and the loss elastic modulus become equal is confirmed within 5 minutes or more and 60 minutes or less after starting the rheometer measurement, and the storage elastic modulus at 25°C after 60 minutes have elapsed since starting the rheometer measurement is 9.0×10 5 Pa or more, a curable thermally conductive adhesive. [2] When measured with the rheometer, the loss elastic modulus of the curable thermally conductive adhesive at 25°C 15 minutes after starting the rheometer measurement is 3.0×10 5 Pa or less, the curable thermally conductive adhesive according to [1]. [3] The curable thermally conductive adhesive according to [1] or [2], wherein the binder contains an epoxy group-containing compound. [4] The curable thermally conductive adhesive according to any one of [1] to [3], wherein the binder contains at least one of an amine and a thiol. [5] The curable thermally conductive adhesive according to any one of [1] to [4], wherein the binder contains an epoxy group-containing compound and an amine. [6] The curable thermally conductive adhesive according to [3] or [5], wherein the epoxy group-containing compound contains a monofunctional epoxy group-containing compound. [7] The curable thermally conductive adhesive according to any one of [1] to [6], wherein the binder contains a Mannich base. [8] The curable thermally conductive adhesive according to any one of [1] to [7], wherein the curable composition contains a polyfunctional acrylate compound, an epoxy group-containing compound, and an amine. [9] The curable thermally conductive adhesive according to any one of [1] to [8], wherein the equivalent ratio, which is the ratio of the equivalent of the active hydrogen of the curing agent to the equivalent of the functional group of the component constituting the main agent contained in the curable composition, is 1.05 or more and 2.9 or less.

[10] A supply form of the curable thermally conductive adhesive according to claim 1 or 2, wherein a first agent containing the main agent of the binder and a second agent containing a curing agent that cures by mixing with the first agent are filled in separate containers, a supply form of the curable thermally conductive adhesive.

[11] The supply form of the curable thermally conductive adhesive according to

[10] , wherein the difference between the viscosity of the first agent and the compression load of the second agent is 450 N or less.

[12] The supply form of the curable thermally conductive adhesive according to

[10] or

[11] , wherein the ratio of the functional group concentration of the second agent to the functional group concentration of the first agent is 1.05 or more and 2.9 or less.

[13] Use as at least one of the gap materials between battery cells, the gap material between a battery cell and a module housing, the gap material between a battery module and the housing of a battery pack, and the gap material between a battery cell and the housing of a battery pack, of the curable thermally conductive adhesive according to any one of [1] to

[10] above. [Advantages of the Invention]

[0010] According to the present invention, it is possible to provide a curable thermally conductive adhesive that has a low viscosity and rapid curability while being able to extend the pot life. [Brief Description of the Drawings]

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

[0012] [Curable Thermally Conductive Adhesive] Hereinafter, the curable thermally conductive adhesive of the present invention will be described in detail. The curable thermally conductive adhesive of the present invention comprises a curable composition containing a curable binder and a thermally conductive filler. In the present invention, when the storage elastic modulus and the loss elastic modulus at 25 °C are measured with a rheometer (hereinafter, this measurement is also referred to as "rheometer measurement"), a gelation point (hereinafter, simply referred to as "gelation point") at which the storage elastic modulus and the loss elastic modulus become equal is confirmed within 5 minutes or more and 60 minutes or less from the start of the measurement. Further, the storage elastic modulus at 25 °C 60 minutes after the start of the measurement is 9.0×10 5 Pa or more.

[0013] <Gelation point> If the gelation point is confirmed within less than 5 minutes from the start of the rheometer measurement, the pot life becomes short, and the adhesive immediately becomes highly viscous after being applied to the substrate, making it difficult to spread the adhesive on the substrate. Further, if the gelation point is confirmed after more than 60 minutes from the start of the rheometer measurement, the development of excellent adhesive strength is delayed, and it becomes difficult for the adhesive to have rapid curability. From these viewpoints, the gelation point is preferably confirmed within 5 minutes or more and 50 minutes or less from the start of the rheometer measurement, and more preferably confirmed within 10 minutes or more and 40 minutes or less from the start of the rheometer measurement. Here, the gelation point refers to the point at which the storage elastic modulus and the loss elastic modulus of the adhesive become equal when the storage elastic modulus and the loss elastic modulus of the adhesive are measured with a rheometer in an environment of 25 °C. As the rheometer, for example, a rheometer "MCR-302e" manufactured by Anton Paar may be used. Note that the measurement method of the time (hereinafter also referred to as "gelation time") at which the gelation point is confirmed is as described in the examples. Further, the gelation point can be adjusted within the above-mentioned predetermined range, for example, by appropriately adjusting the main agent of the binder component and the type and amount of the curing agent.

[0014] <Storage elastic modulus> The storage elastic modulus at 25 °C (hereinafter, also referred to as "elastic modulus G'(60)") 60 minutes after the start of the rheometer measurement is 9.0×10 5If it is less than Pa, it becomes difficult for the adhesive to exhibit excellent adhesiveness. From this perspective, the elastic modulus G’(60) is preferably 9.2×10 5 Pa or more, and more preferably 1.0×10 6 Pa or more. The upper limit of the elastic modulus G’(60) is not particularly limited, but from the perspective that the adhesive can exhibit appropriate adhesiveness, it is preferably 1.0×10 7 Pa or less, more preferably 8.0×10 6 Pa or less, and even more preferably 5.0×10 6 Pa or less. The elastic modulus G’(60) can be obtained by the measurement method described in the examples.

[0015] The adhesive of the present invention has a loss elastic modulus (hereinafter, also referred to as “elastic modulus G’’(15)”) at 25°C 15 minutes after the start of the rheometer measurement of 3.0×10 5 Pa or less, preferably 2.5×10 5 Pa or less, and more preferably 2.0×10 5 Pa or less. When the elastic modulus G’’(15) is below the above upper limit value, the curing of the adhesive is not too fast, and it is easy to extend the pot life. Also, for example, the adhesive strength after 18 hours is likely to be a certain level or more. On the other hand, from the perspective of ensuring a certain degree of rapid curing property of the adhesive, the elastic modulus G’’(15) is preferably 2.0×10 3 Pa or more, more preferably 2.2×10 3 Pa or more, and even more preferably 2.5×10 3 Pa or more. The elastic modulus G’’(15) can be obtained by the measurement method described in the examples.

[0016] The adhesive of the present invention has a storage elastic modulus (hereinafter, simply referred to as “elastic modulus G’(15)”) at 25°C 15 minutes after the start of the rheometer measurement of 2.5×10 6 Pa or less, preferably 2.0×10 6 Pa or less, and more preferably 1.7×10 6It is more preferably below Pa. When the elastic modulus G’(15) is below the above upper limit value, the curing of the adhesive is not too fast, and it becomes easier to lengthen the pot life. Also, for example, the adhesive strength after 18 hours is likely to be at least a certain level. On the other hand, from the viewpoint of ensuring a certain degree of fast curability of the adhesive, the elastic modulus G’(15) is preferably 5.0×10 2 Pa or more, more preferably 8.0×10 2 Pa or more, and even more preferably 1.0×10 3 Pa or more. Note that the elastic modulus G’(15) can be obtained by the measuring method described in the examples. Also, the elastic modulus G’(60), the elastic modulus G’’(15), and the elastic modulus G’(15) can be adjusted within the above-mentioned predetermined ranges, for example, by appropriately adjusting the main agent of the binder component and the type and amount of the curing agent. Also, the elastic modulus G’(60) and the elastic modulus G’(15) tend to increase by accelerating the curability.

[0017] <Thermal conductivity> For the adhesive of the present invention, the thermal conductivity of its cured product is preferably 1.3 W / (m·K) or more, more preferably 1.5 W / (m·K) or more, and even more preferably 1.6 W / (m·K) or more. By setting the thermal conductivity of the cured product of the adhesive to be at least these lower limit values, the thermal conductivity becomes good. Therefore, for example, when used in a battery cell assembly, the heat generated from the battery cell can be efficiently transmitted to the module housing or the battery pack via the cured product (thermal conductive member) of the adhesive, and an excessive increase in the temperature of the battery cell can be suppressed. Although the higher the above thermal conductivity is, the better, practically, it is, for example, 7.0 W / (m·K) or less. The thermal conductivity can be measured by a method compliant with ASTM D5470-06. Specifically, an adhesive is disposed in an amount greater than the thickness during measurement so as to cover the measurement die on the heating element side, and then it is sandwiched between heat radiators and compressed with a load of 30 psi until the thickness of the adhesive becomes 1.0 mm, 1.5 mm, or 2.0 mm, and the thermal resistance at each thickness is measured. The thickness can be adjusted with spacers. For the values of these three thermal resistances, a graph is created with the thickness on the horizontal axis and the thermal resistance value on the vertical axis, and an approximate straight line passing through three points is obtained by the least squares method. Then, the slope of the approximate straight line is taken as the thermal conductivity.

[0018] <Adhesive strength> The adhesive of the present invention preferably has an adhesive strength (hereinafter also referred to as "adhesive strength 1") of 0.03 MPa or more and 0.7 MPa or less, more preferably 0.05 MPa or more and 0.5 MPa or less, and even more preferably 0.08 MPa or more and 0.3 MPa or less, 1 hour after the start of mixing of each component. When the adhesive strength 1 is equal to or higher than the above lower limit value, the minimum adhesive strength required for temporarily fixing the member can be ensured. Further, when the adhesive strength 1 is equal to or lower than the above upper limit value, after temporarily fixing the member, the member can be easily peeled off when correcting the position of the member or the like.

[0019] Further, the adhesive of the present invention preferably has an adhesive strength (hereinafter also referred to as "adhesive strength 2") of 0.8 MPa or more, more preferably 0.9 MPa or more, and even more preferably 1.2 MPa or more, 18 hours after the start of mixing of each component. When the adhesive strength 2 is equal to or higher than the above lower limit value, it means that the adhesive has sufficiently cured. For example, when transporting a member adhered via the adhesive, even if vibration due to transportation is applied, it is possible to prevent the member from peeling off. The upper limit of the adhesive strength 2 is not particularly limited, but practically it is, for example, 5 MPa or less, preferably 3 MPa or less, and more preferably 2 MPa or less. Note that each of the above-described adhesive strengths can be obtained by the measurement method described in the examples.

[0020] [Binder] The adhesive of the present invention contains a curable binder. The curable binder may be thermosetting, photocurable, or moisture-curable, but is preferably thermosetting. Also, the binder may be either a one-component curing type or a two-component curing type, but is preferably the two-component curing type. The two-component curing type is used by mixing a first agent containing a main agent and a second agent containing a curing agent, and it is advisable to start curing by mixing the first agent and the second agent. Therefore, in the two-component curing type, it is advisable to use, as the curing agent, one that cures by mixing with the main agent of the first agent. Also, the curing agent is preferably one that can cure at room temperature (25°C) when mixed with the main agent of the first agent.

[0021] The binder is preferably any one of urethane-based, silicone-based, acrylic-based, epoxy-based, or an organic polymer having a hydrolyzable silyl group, and among these, the epoxy-based is preferred. Using these specific binders makes it easier to impart fast-curing properties to the adhesive or to extend the pot life. The binder may be used alone or in combination of two or more.

[0022] Here, the urethane-based binder includes, for example, those composed of a polyol compound as the main agent and a polyisocyanate compound as the curing agent. The silicone-based binder may be either a condensation-curing type silicone resin or an addition-reaction-curing type silicone resin, but the addition-reaction-curing type silicone resin is preferred. The addition-reaction-curing type silicone resin preferably consists of a silicone resin constituting the main agent and a curing agent for curing the main agent. For example, in the case of an addition-reaction-curing type silicone resin, it is advisable to use an organopolysiloxane having an alkenyl group as the main agent and an organohydrogenpolysiloxane as the curing agent.

[0023] The epoxy-based binder preferably consists of an epoxy group-containing compound as the main agent and a curing agent. The acrylic binder may be a component that forms an acrylic polymer upon curing. For example, it may include alkyl (meth)acrylate, hydroxyalkyl (meth)acrylate, (meth)acrylic acid, (meth)acrylamides, urethane (meth)acrylate, and the like. Further, the acrylic binder may contain a vinyl monomer copolymerizable with the above acrylic compound. Furthermore, at least a part of the acrylic binder may be a polymer of an acrylic compound, a copolymer of an acrylic compound and a vinyl monomer, and the like. Also, the acrylic binder may be a monofunctional acrylate compound or a polyfunctional acrylate compound.

[0024] The organic polymer having a hydrolyzable silyl group has a hydrolyzable silyl group, and after being hydrolyzed by moisture such as water to form a silanol group, a siloxane bond can be formed by the condensation polymerization of silanol groups or between a silanol group and a hydrolyzable silyl group. Thereby, the organic polymer forms a crosslinked structure and cures to obtain a rubber-like elastic body. The silanol group means a hydroxy group (Si-OH) directly bonded to a silicon atom. The hydrolyzable silyl group is preferably an alkoxysilyl group, and specific examples include a trimethoxysilyl group, a dimethoxysilyl group, a triethoxysilyl group, and a diethoxysilyl group. On the other hand, examples of the organic polymer include polyethers such as polyalkylene oxide. Hereinafter, the case of using an epoxy type as the binder will be described in detail.

[0025] (Compound containing an epoxy group) As described above, when the binder is an epoxy type, it is preferably to contain a compound containing an epoxy group. By using a compound containing an epoxy group, it becomes easy to adjust the adhesive strength of the adhesive within an appropriate range. The compound containing an epoxy group may be any compound having one or more epoxy groups. The compound containing an epoxy group may be a polyfunctional compound containing two or more epoxy groups or a monofunctional compound containing one epoxy group.

[0026] The adhesive of the present invention preferably contains at least a polyfunctional epoxy group-containing compound. By containing a polyfunctional epoxy group-containing compound, the reaction rate between the main agent and the curing agent increases, the time to confirm the gel point becomes earlier, and rapid curability is easily exhibited. In addition to the polyfunctional epoxy group-containing compound, the adhesive may further contain a monofunctional epoxy group-containing compound. By further containing a monofunctional epoxy group-containing compound, the reaction rate between the main agent and the curing agent becomes appropriate, the pot life can be easily lengthened, and the initial viscosity can be easily lowered. Furthermore, it is possible to prevent the time to confirm the gel point from becoming too early.

[0027] 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, still more preferably 20 / 80 or more and 70 / 30 or less, and even more preferably 25 / 75 or more and 60 / 40 or less.

[0028] Examples of the polyfunctional epoxy group-containing compound include bifunctional or trifunctional ones, and preferably a bifunctional epoxy group-containing compound is used. Specific examples of the polyfunctional epoxy group-containing compound include epoxy resins having an aromatic skeleton such as phenol novolac type epoxy resin, resorcinol type epoxy resin, epoxy resin having a bisphenol skeleton, epoxy resin having a naphthalene skeleton, epoxy resin having a fluorene skeleton, epoxy resin having a biphenyl skeleton, epoxy resin having a bis(glycidyloxyphenyl)methane skeleton, epoxy resin having a xanthene skeleton, epoxy resin having an anthracene skeleton, and epoxy resin having a pyrene skeleton. In addition, epoxy resins having an alicyclic skeleton such as epoxy resin having a dicyclopentadiene skeleton and epoxy resin having an adamantane skeleton are also included. Furthermore, aliphatic epoxy resins such as polyalkylene glycol diglycidyl ethers including butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, trimethylolpropane polyglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, and polytetramethylene glycol diglycidyl ether can also be mentioned. In addition, hydrogenated products or modified products of the above-exemplified epoxy resins can also be used as epoxy resins.

[0029] Examples of the epoxy resins having the above-mentioned bisphenol skeleton include epoxy resins having a bisphenol A-type, bisphenol F-type, or bisphenol S-type bisphenol skeleton. Examples of the above-mentioned resorcinol-type epoxy resins include resorcinol diglycidyl ether. Examples of the epoxy resins having the above-mentioned 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. Examples of the epoxy resins having the above-mentioned 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.

[0030] Examples of the epoxy resin having the biphenyl skeleton include 4,4'-diglycidylbiphenyl and 4,4'-diglycidyl-3,3',5,5'-tetramethylbiphenyl. Examples of the epoxy resin having the 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.

[0031] Examples of the epoxy resin having the xanthene skeleton include 1,3,4,5,6,8-hexamethyl-2,7-bis-glycidylmethoxy-9-phenyl-9H-xanthene. Examples of the epoxy resin having the anthracene skeleton include those having one or more anthracene skeletons and two or more epoxy groups or glycidyl groups in one molecule.

[0032] Examples of the epoxy resin having the pyrene skeleton include those having one or more pyrene skeletons and two or more epoxy groups or glycidyl groups in one molecule. Examples of the epoxy resin having the dicyclopentadiene skeleton include dicyclopentadiene dioxide and a phenol novolak epoxy resin having a dicyclopentadiene skeleton. Examples of the epoxy resin having the adamantane skeleton include 1,3-bis(4-glycidyloxyphenyl)adamantane and 2,2-bis(4-glycidyloxyphenyl)adamantane.

[0033] Among the above, as the bifunctional epoxy group-containing compound, from the viewpoint of increasing the storage elastic modulus and easily improving the adhesive strength and mechanical strength, an epoxy resin having an aromatic skeleton is preferable, and among them, a bisphenol-type epoxy resin which is an epoxy resin having a bisphenol skeleton is more preferable. Further, it is also preferable to use in combination an epoxy resin having an aromatic skeleton and an aliphatic epoxy resin. The bifunctional epoxy group-containing compound may be used alone or in combination of two or more.

[0034] Examples of the monofunctional epoxy group-containing compound include phenyl glycidyl ethers such as alkyl phenyl glycidyl ethers typified by phenyl glycidyl ether, 4-t-butylphenyl glycidyl ether, cresyl glycidyl ether, and nonylphenyl glycidyl ether, and monofunctional epoxy group-containing compounds having an aromatic ring such as 1-glycidyl naphthalene and 2-glycidyl naphthalene. As the monofunctional epoxy group-containing compound having an aromatic ring, an epoxy group-containing compound having a phenyl group is more preferable. By using the monofunctional epoxy group-containing compound having an aromatic ring, it becomes easy to increase the storage elastic modulus and the adhesive strength.

[0035] In addition, as the monofunctional epoxy group-containing compound, from the viewpoint of high raw material safety, an aliphatic monofunctional epoxy group-containing compound is also preferable. Specifically, examples include glycidyl ethers of aliphatic alcohols. Here, as the aliphatic alcohol, those having a branched structure or a linear structure may be used, but from the viewpoint of good elongation, a linear structure is preferable. Further, as the aliphatic alcohol, for example, it may have about 4 to 24 carbon atoms, preferably 10 to 20 carbon atoms. Also, from the viewpoint of good elongation, the aliphatic alcohol is preferably a saturated aliphatic alcohol. Specific examples of the glycidyl ether of the aliphatic alcohol include butyl glycidyl ether, decyl glycidyl ether, lauryl glycidyl ether, myristyl glycidyl ether, cetyl glycidyl ether, stearyl glycidyl ether, and the like. The monofunctional epoxy group-containing compound may be other than the above, and examples also include monofunctional epoxy group-containing compounds having a glycidyl group and no ether group, such as 1,2-epoxybutane and propylene oxide. The monofunctional epoxy group-containing compound may be used alone or in combination of two or more.

[0036] For the epoxy group-containing compound, for example, those having a molecular weight of 2000 or less are preferably used, more preferably 1000 or less, and even more preferably 500 or less. By using an epoxy group-containing compound having a molecular weight below a certain value, the viscosity of the adhesive can be lowered, and it is also possible to highly fill the thermal conductivity filler. The molecular weight of the epoxy group-containing compound is, for example, 100 or more, preferably 150 or more, more preferably 200 or more, and even more preferably 250 or more. By setting the molecular weight of the epoxy group-containing compound to be above a certain value, it is possible to prevent the crosslinking density from becoming too high and to easily improve the elongation. Note that the epoxy group-containing compound is preferably liquid at room temperature (25 °C).

[0037] The epoxy equivalent of the epoxy group-containing compound is preferably 1000 g / eq or less, more preferably 500 g / eq or less, still more preferably 375 g / eq or less, and is also preferably 100 g / eq or more, more preferably 125 g / eq or more, still more preferably 140 g / eq or more.

[0038] The epoxy group-containing compound is preferably liquid at room temperature (25 °C). Also, the viscosity of the epoxy resin at 25 °C is not particularly limited, but for example, it may be 50 Pa·s or less, preferably 10 Pa·s or less. Also, the viscosity of the epoxy resin at 25 °C is not particularly limited, but for example, it may be 0.5 mPa·s or more, or 1 mPa·s or more. The viscosities of the epoxy resin and the amine compound described later are the viscosities measured using an E-type viscometer under the conditions of 10 rpm and 25 °C.

[0039] The content of the epoxy group-containing compound in the adhesive is, for example, 2% by mass or more and 20% by mass or less based on the total amount of the curable composition. When the content of the epoxy group-containing compound is 2% by mass or more, it is easy to increase the adhesive strength and elongation. Also, when it is 20% by mass or less, it is difficult for the components of the uncured epoxy group-containing compound to exist, and it is possible to prevent the adhesion from being inhibited by the uncured components. The content of the epoxy group-containing compound is preferably 3% by mass or more and 15% by mass or less, more preferably 4% by mass or more and 12% by mass or less, still more preferably 5% by mass or more and 10% by mass or less based on the total amount of the curable composition.

[0040] (Hardener) The binder preferably contains a hardener for curing the main agent. Specifically, it preferably contains at least one of an amine and a thiol. At least one of the amine and the thiol is preferably used when the binder contains an epoxy group-containing compound. By containing an amine or a thiol as a hardener, the binder is easily adjusted to a practical curing rate at room temperature. Also, the adhesive strength of the adhesive is easily increased.

[0041] As the amine, polyamines such as diamines and triamines may be used, or monoamines may be used, but polyamines such as diamines and triamines are preferred.

[0042] Specific amines include polyoxyalkylene amines such as polyoxyethylene diamine, poly(oxyethylene / oxypropylene) diamine, polyoxypropylene diamine, poly(oxybutylene / oxypropylene) diamine, polyethylene glycol bis(propylamine), trimethylolpropane poly(oxypropylene) triamine, glyceryl poly(oxypropylene) triamine, methoxypoly(oxyethylene / oxypropylene)-2-propylamine, aromatic ring-containing amines such as m-phenylenediamine, p-phenylenediamine, m-xylylenediamine, p-xylylenediamine, tolylene-2,4-diamine, tolylene-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-naphthylenediamine, 2,6-naphthylenediamine, reaction product of m-xylylenediamine and styrene, aliphatic amines such as 1,6-hexanediamine, 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, 2,7-dimethyl-1,8-octanediamine, alicyclic amines such as 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, cyclohexanediamine, methylcyclohexanediamine, isophoronediamine, amidoamine, and the like. Examples of the amidoamine include those obtained by reacting aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, carboxylic acid compounds such as fatty acids and dimer acids, with aliphatic polyamines or polyamines having a polyoxyalkylene chain.

[0043] Also, as the amine, a Mannich base may be used. As the Mannich base, a Mannich base that can be used as an amine curing agent may be used. For example, it is preferable to use one obtained by the reaction of a phenolic compound, an aldehyde compound, and an amine compound. By containing a Mannich base using a phenolic compound, the reaction between the main agent and the curing agent is promoted by the phenolic structure contained in the Mannich base, the time for confirming the gel point is advanced, and excellent rapid curability is likely to be exhibited. Among the Mannich bases, it is preferable to use a phenalkamine type Mannich base.

[0044] Among the above, from the viewpoint of making the reaction rate with the main agent equal to or higher than a certain level and easily ensuring rapid curability, it is more preferable to use polyamines, especially triamines, and it is even more preferable to use diamines and triamines in combination. The reaction rates of diamines and triamines with the main agent are different. By using two or more amines with different reaction rates in combination, it becomes possible to partially advance the reaction between the main agent and the curing agent. Therefore, the time for confirming the gel point can be set within a predetermined range, and the pot life can be extended while ensuring rapid curability. In this case, it is more preferable that both the diamines and the triamines are polyoxyalkylene amines.

[0045] When using amidoamine, it is preferable to use it in combination with diamines and triamines other than amidoamine. Further, when using Mannich base, as the amine curing agent, it is preferable to use it in combination with Mannich base and diamines and triamines other than Mannich base, and it is more preferable to use it in combination with triamines. In these cases, both diamines and triamines are preferably polyoxyalkylene amines. As described above, by using two kinds of amines as the amine curing agent, the time for confirming the gelation point can be set within a predetermined range, and while ensuring rapid curability, the pot life can be extended.

[0046] From the viewpoint of enhancing rapid curability and reducing the viscosity of the adhesive before curing, the molecular weight of the amine used as the curing agent is preferably 3000 or less, more preferably 1000 or less, still more preferably 600 or less, and even more preferably 500 or less. Also, the molecular weight of the amine curing agent is not particularly limited, but is, for example, 100 or more, preferably 150 or more, and more preferably 200 or more.

[0047] From the viewpoint of enhancing rapid curability and reducing the viscosity of the adhesive before curing, the viscosity of the amine used as the curing agent at 25°C is preferably 15 Pa·s or less, more preferably 10 Pa·s or less, still more preferably 5 Pa·s or less, and even more preferably 3 Pa·s or less. Also, the viscosity of the amine curing agent at 25°C is not particularly limited, but is, for example, 0.03 Pa·s or more, preferably 0.05 Pa·s or more, and more preferably 0.07 Pa·s or more.

[0048] The content of the amine in the adhesive is, for example, 2% by mass or more and 20% by mass or less based on the total amount of the curable composition. When the content of the amine is 2% by mass or more, the main agent is sufficiently cured, and it is easy to increase the elastic modulus G’(60) and the adhesive strength. Also, when it is 20% by mass or less, the main agent can be cured without containing an excessive amount of amine. The amine content is preferably 3% by mass or more and 15% by mass or less, more preferably 4% by mass or more and 12% by mass or less, and still more preferably 5% by mass or more and 10% by mass or less, based on the total amount of the curable composition.

[0049] Examples of the thiol include polythiols such as dithiols and trithiols. Specific thiols include esters of polyols and mercapto organic acids such as pentaerythritol tetrakis(3-mercaptobutyrate), 1,4-bis(3-mercaptobutyryloxy)butane, trimethylolpropane tris(3-mercaptobutyrate), aliphatic thiols such as alkanedithiols, and aromatic ring-containing thiols such as xylylenedithiol.

[0050] The active hydrogen equivalent of the amine and thiol contained in the adhesive is not particularly limited, but is, for example, 15 g / eq or more, preferably 25 g / eq or more, more preferably 30 g / eq or more, and is, for example, 250 g / eq or less, preferably 200 g / eq or less, more preferably 150 g / eq or less.

[0051] In the present invention, when an epoxy-based binder is used, in addition to the epoxy group-containing compound, it is preferable to further contain a polyfunctional acrylate compound as the main agent. That is, the binder may be composed of an epoxy group-containing compound as the main agent and a curing agent represented by an amine, or may be composed of an epoxy group-containing compound as the main agent, a polyfunctional acrylate compound, and a curing agent represented by an amine. The polyfunctional acrylate compound used in combination with the epoxy group-containing compound is as follows.

[0052] (Polyfunctional acrylate compound) A polyfunctional acrylate compound is a compound having 2 or more functional groups (i.e., the number of (meth)acryloyl groups). Since the polyfunctional acrylate compound reacts rapidly with the above-described curing agent, particularly an amine, using the polyfunctional acrylate compound makes it easier to confirm the gel point at an early stage, imparts rapid curability to the adhesive, and imparts a certain adhesive strength in the initial stage of curing. As the polyfunctional acrylate compound, it is preferable to use a polyfunctional (meth)acrylate, and it is more preferable to use a polyfunctional polyol and an ester of (meth)acrylic acid. In addition, in this specification, the "(meth)acryloyl group" means either an acryloyl group or a methacryloyl group, the "(meth)acrylate" means either an acrylate or a methacrylate, and the same applies to other similar terms.

[0053] Among the polyfunctional acrylate compounds, examples of bifunctional ones 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, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, ethylene oxide adduct bisphenol A di(meth)acrylate, propylene oxide adduct bisphenol A di(meth)acrylate, ethylene oxide adduct bisphenol F di(meth)acrylate, dimethylol dicyclopentenyl 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.

[0054] Among polyfunctional acrylate compounds, those with three or more functional groups include, for example, trimethylolpropane tri(meth)acrylate, glycerin tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, alkylene oxide-added trimethylolpropane tri(meth)acrylate such as ethylene oxide-added trimethylolpropane tri(meth)acrylate and propylene oxide-added trimethylolpropane tri(meth)acrylate, caprolactone-modified trimethylolpropane tri(meth)acrylate, ethylene oxide-added isocyanuric acid tri(meth)acrylate, propylene oxide-added glycerin tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, alkylene oxide-added pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tripentaerythritol octa(meth)acrylate, tetrapentaerythritol deca(meth)acrylate, tripentaerythritol hepta(meth)acrylate, tetrapentaerythritol nona(meth)acrylate, and the like.

[0055] The number of functional groups of the polyfunctional acrylate compound is preferably 3 or more, more preferably 4 or more, and even more preferably 5 or more. When the number of functional groups of the polyfunctional acrylate compound increases, the time to confirm the gel point becomes earlier, the rapid curability is enhanced, and the adhesive strength at the initial stage of curing is likely to increase. The upper limit of the number of functional groups of the polyfunctional acrylate compound is not particularly limited, and may be, for example, 10 or less, or 8 or less.

[0056] From the perspective of enhancing rapid curability and reducing the viscosity of the adhesive before curing, the molecular weight of the polyfunctional acrylate compound is preferably below a certain level. For example, the molecular weight of a specific polyfunctional acrylate compound may be 5000 or less, preferably 3000 or less, more preferably 1000 or less, and even more preferably 700 or less. Also, for the molecular weight of the polyfunctional acrylate compound, it is advisable to use those with a molecular weight of, for example, 150 or more, preferably 200 or more, more preferably 250 or more, and even more preferably 450 or more. By setting the molecular weight of the above polyfunctional acrylate compound to be above a certain value, the compressive load at the initial stage of curing can be moderately reduced, and it is possible to prevent the crosslinking density from becoming excessively high, making it easier to improve elongation and adhesive strength. From the perspective of facilitating the reduction of the viscosity of the adhesive before curing, the polyfunctional acrylate compound is preferably liquid at room temperature (25 °C).

[0057] The functional group equivalent of the polyfunctional 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. Also, it is preferably 75 g / eq or more, more preferably 80 g / eq or more, and even more preferably 85 g / eq or more.

[0058] In the adhesive, the ratio of the number of functional groups of the polyfunctional acrylate compound to the number of functional groups of the epoxy resin may be about 0.1 or more and 1.5 or less, preferably 0.2 or more and 1.2 or less, more preferably 0.3 or more and 1.0 or less, and even more preferably 0.4 or more and 0.85 or less. When the ratio of the number of functional groups of the polyfunctional acrylate compound is within a predetermined range, the amine and the polyfunctional acrylate compound are preferentially cured at the initial stage, and rapid curability is exhibited. On the other hand, the reaction between the amine and the epoxy resin is suppressed, so the compressive load at the initial stage of curing is maintained low, and the pot life can be extended.

[0059] The content of the polyfunctional acrylate compound is, based on the total amount of the curable composition, for example, 10% by mass or less, preferably 8% by mass or less. When the content of the polyfunctional acrylate compound is set below the above upper limit value, it is possible to prevent the initial curing from progressing too far due to the polyfunctional acrylate compound, and it becomes easier to lengthen the pot life. Also, when the content of the polyfunctional acrylate compound is reduced, the moisture resistance is also improved. Therefore, for example, even when used for a long time under high temperature and high humidity after curing, a high adhesive strength can be maintained. The content of the polyfunctional acrylate compound is more preferably 6% by mass or less, and even more preferably 4% by mass or less. Also, the content of the polyfunctional acrylate compound should preferably be a certain amount or more in order to exhibit rapid curability and increase the adhesive force in the initial stage of curing. Based on the total amount of the curable composition, for example, it is 0.3% by mass or more, preferably 0.5% by mass or more, more preferably 1% by mass or more, and even more preferably 1.5% by mass or more.

[0060] The equivalent ratio in the curable composition is preferably 1.05 or more and 2.9 or less. Note that the equivalent ratio in the curable composition is the equivalent ratio of the curing agent to the main agent constituting the binder. Specifically, it is the ratio of the number of active hydrogens of the curing agent to the number of functional groups of the components constituting the main agent contained in the curable composition. Therefore, when the binder consists of an epoxy group-containing compound and an amine, it is the equivalent of the active hydrogen of the amino group contained in the amine with respect to the equivalent of the epoxy group contained in the epoxy group-containing compound. Also, when the binder consists of an epoxy group-containing compound, a polyfunctional (meth)acrylate, and an amine, it is the equivalent of the active hydrogen of the amino group with respect to the total of the equivalent of the epoxy group contained in the epoxy group-containing compound and the equivalent of the (meth)acryloyl group contained in the polyfunctional acrylate compound. Furthermore, when the binder consists of an epoxy group-containing compound and a thiol, it is the ratio of the equivalent of the active hydrogen of the thiol group contained in the thiol to the equivalent of the epoxy group contained in the epoxy group-containing compound. Also, when the binder consists of an epoxy group-containing compound, an amine, and a thiol, it is the ratio of the total equivalent of the active hydrogen of the thiol group contained in the thiol to the equivalent of the amino group contained in the amine to the equivalent of the epoxy group contained in the epoxy group-containing compound. When the equivalent ratio of the above functional groups is 1.05 or more, the number of active hydrogens of the amino group becomes appropriate, a certain reaction proceeds even in the initial stage of curing, and rapid curability is easily obtained. Also, when it is 2.9 or less, the number of active hydrogens of the amino group does not become too large, the compressive load in the initial stage of curing becomes low, and the pot life is easily lengthened. Further, by setting the equivalent ratio within the above predetermined range, it becomes easy to adjust the adhesive strength to an appropriate range. The equivalent ratio of the above functional groups is more preferably 1.2 or more, further preferably 1.3 or more, even more preferably 1.4 or more, and more preferably 2.6 or less, further preferably 2.1 or less, and even more preferably 1.8 or less.

[0061] The equivalent of the epoxy group 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 kinds of epoxy resins are contained, it can be obtained by summing up the values obtained by dividing the content (g) of each epoxy resin by the epoxy equivalent (g / eq). The equivalent of the active hydrogen of the amino group can be obtained by dividing the content (g) of the amine in the curable composition by the active hydrogen equivalent of the amine (g / eq). However, when two or more kinds of amines are contained, it can be obtained by summing up the values obtained by dividing the content (g) of each amine by the active hydrogen equivalent (g / eq). Furthermore, the equivalent of the (meth)acryloyl group 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 kinds of acrylate compounds are contained, it can be obtained by summing up the values obtained by dividing the content (g) of each acrylate compound by the (meth)acryloyl equivalent (g / eq). Note that 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. The active hydrogen equivalent (g / eq) can be obtained by dividing the molecular weight of the amine by the number of active hydrogen atoms per molecule. Furthermore, the (meth)acryloyl equivalent (g / eq) can be obtained by dividing the molecular weight of the acrylate compound by the number of (meth)acryloyl groups per molecule. The equivalent of the active hydrogen of the thiol group is, for example, a value obtained by multiplying the amount of active hydrogen per unit amount of thiol (mol / g) in the adhesive by the content of thiol. However, when two or more kinds of thiols are contained, it is the sum of the values obtained by multiplying the amount of active hydrogen per unit amount of each thiol (mol / g) by the content of each thiol. When both an amine and a thiol are contained, the equivalents of the active hydrogens of the amino group and the thiol group are the sum of the equivalent of the active hydrogen of the amino group and the equivalent of the active hydrogen of the thiol group in the adhesive.

[0062] The molecular weight, the equivalent of the epoxy group, the equivalent of the active hydrogen, and the number of (meth)acryloyl groups can be measured with a mass spectrometer (GC-MS or LC-MS). When only the molecular weight can be specified with a mass spectrometer, the number (equivalent) of epoxy groups and the number (equivalent) of active hydrogen atoms per molecule can be specified by NMR ( 1 1H NMR, etc.). However, when the sample is a mixture, it is preferable to isolate each component by GPC (gel permeation chromatography) or HPLC (high performance liquid chromatography) and then measure NMR. When the structural formula of the epoxy resin is known, the molecular weight and the number of epoxy groups are the molecular weight and the number of epoxy groups of the epoxy resin that can be calculated from the structural formula. Similarly, when the structural formula of the amine is known, the molecular weight and the number of active hydrogen atoms are the molecular weight and the number of active hydrogen atoms of the amine that can be calculated from the structural formula. The same applies to the acrylate compound. The same also applies to thiol. Note that the number of active hydrogens of an amine is set to 1 for NHR2 (secondary amino group) and 2 for NH2R (primary amino group) (however, in NHR2 and NH2R, R is a functional group other than the active hydrogen, that is, the part other than the NH or NH2 of the amine). Also, the number of active hydrogens of a thiol is set to 1 for SHR (however, R is a functional group other than the active hydrogen, that is, the part other than the SH of the thiol).

[0063] The content rate of the binder in the adhesive is preferably 8% by volume or more and 55% by volume or less with respect to the total volume of the adhesive. When it is at least the above lower limit value, the heat conductive filler can be appropriately dispersed in the heat conductive member and the adhesive. Also, it can prevent the viscosity of the adhesive from becoming unnecessarily high. Further, when it is at most the above upper limit value, it becomes easy to contain a certain amount or more of the heat conductive filler in the adhesive. The content rate of the binder in the adhesive is more preferably 15% by volume or more and 45% by volume or less, and even more preferably 18% by volume or more and 38% by volume or less.

[0064] [Thermal Conductive Filler] The adhesive of the present invention contains a thermal conductive filler. By containing the thermal conductive filler in the adhesive, the thermal conductivity of the heat conductive member formed by the adhesive is improved. Examples of the thermal conductive filler include metals, metal oxides, metal nitrides, metal hydroxides, carbon materials, oxides, nitrides, carbides other than metals, etc. Also, examples of the shape of the thermal conductive filler include spherical and amorphous powders. In the case of the heat conductive filler, examples of metals include aluminum, copper, nickel, etc.; examples of metal oxides include aluminum oxide typified by alumina, magnesium oxide, zinc oxide, etc.; examples of metal nitrides include aluminum nitride, etc. An example of the metal hydroxide is aluminum hydroxide. Further, examples of the carbon material include spherical graphite, etc. Examples of oxides, nitrides, and carbides other than metals include quartz, boron nitride, silicon carbide, etc. Among these, from the viewpoint of improving the heat dissipation property of the heat conductive member, aluminum oxide is preferable, and aluminum hydroxide is preferable when it is desired to enhance the flame retardancy. It is also preferable to use aluminum oxide and aluminum hydroxide in combination. The heat conductive filler may be used alone or in combination of two or more of the above-mentioned ones.

[0065] The average particle size of the heat 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. The heat conductive filler is preferably used in combination of a small particle size heat conductive filler having an average particle size of 0.1 μm or more and 5 μm or less and a large particle size heat conductive filler having an average particle size of more than 5 μm and 200 μm or less. By using heat conductive fillers having different average particle sizes, the filling rate can be increased. The average particle size of the heat conductive filler can be measured by observing with an electron microscope or the like. More specifically, for example, using an electron microscope or an optical microscope, the particle sizes of 50 arbitrary heat conductive fillers can be measured, and the average value (arithmetic mean value) can be taken as the average particle size.

[0066] The content rate of the heat conductive filler in the curable composition is preferably 40% by volume or more and 90% by volume or less with respect to the whole volume of the adhesive. When it is not less than the above lower limit value, a certain heat conductivity can be imparted to the adhesive. Further, by setting the content of the heat conductive filler to not more than the above upper limit value, the heat conductive filler can be appropriately dispersed in the heat conductive member, and it is possible to prevent the viscosity of the adhesive from becoming excessively high. In the present invention, by reducing the viscosity of the adhesive, it becomes easier to increase the content rate of the heat conductive filler. The content rate of the heat conductive filler in the adhesive is more preferably 50% by volume or more and 85% by volume or less, and even more preferably 60% by volume or more and 78% by volume or less. When the content of the heat conductive filler in the curable composition is expressed in parts by mass, it 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 with respect to 100 parts by mass of the binder.

[0067] (Dispersant) The curable composition of the present invention may contain a dispersant. Examples of the dispersant include polymer dispersants. Examples of the polymer dispersant include polymer compounds having functional groups. Examples of the polymer compound include acrylic, vinyl, polyester, polyurethane, polyether, epoxy, polystyrene, amino, silicone, etc. Examples of the functional group include carboxyl group, phosphoric acid group, sulfonic acid group, carboxylic acid ester group, phosphoric acid ester group, sulfonic acid ester group, hydroxyl group, amino group, quaternary ammonium base, amide group, etc. Further, as the dispersant, other than the polymer dispersant, for example, an alkoxysilane compound may be used. The content of the dispersant in the adhesive is preferably 0.1 part by mass or more and 10 parts by mass or less, more preferably 0.2 part by mass or more and 5 parts by mass or less, and even more preferably 0.4 part by mass or more and 3 parts by mass or less with respect to 100 parts by mass of the binder.

[0068] (Water) The curable composition of the present invention may contain water. By containing water, the adhesive can make water function as a catalyst, facilitating the reaction between the main agent and the curing agent, particularly between an acrylic compound and an amine. The water content is preferably 0.1% by mass or more and 3.0% by mass or less based on the total amount of the curable composition. When the water content is 0.3% by mass or more, the reaction between the main agent and the curing agent can be appropriately promoted by water. Also, when it is 2.0% by mass or less, problems such as the physical properties of the cured product of the adhesive deteriorating due to an excessive amount of water or the curing progressing too much due to water and the pot life becoming short are less likely to occur. The water content is more preferably 0.3% by mass or more and 2.0% by mass or less, and even more preferably 0.5% by mass or more and 1.5% by mass or less. Also, when the adhesive contains water, even if the amount of the curing agent is relatively small, the curing reaction can be made to proceed more easily, and even if the equivalent ratio is relatively low, the gel point can be made relatively early. The water content in the curable composition can be determined by measuring it by the Karl Fischer method.

[0069] (Other additives) The curable composition of the present invention may contain additives other than those described above. Such additives include curing catalysts such as bisphenol F that promote the reaction between the main agent and the curing agent other than water, reaction rate control agents (reaction retardants) that suppress the reaction between the main agent and the curing agent, thixotropic agents such as amides, flame retardants, plasticizers, antioxidants such as phenolic antioxidants, and colorants. When using a plasticizer, it is preferable to use one with a high molecular weight, and it is more preferable to use a reactive plasticizer or a substantially non-volatile plasticizer.

[0070] <Supply form> The supply form of the adhesive of the present invention may be a one-component type or a two-component type formed by combining a first agent and a second agent. From the viewpoint of storage stability, the two-component type is preferable. In a two-component adhesive, the volume ratio of the first component to the second component (second component / first component) is preferably 1 or a value close to 1. Specifically, it is preferably 0.9 or more and 1.1 or less, and more preferably 0.95 or more and 1.05 or less. By setting the volume ratio of the first component to the second component to 1 or a value close to 1 in this way, the preparation of the adhesive becomes easier.

[0071] Further, in a two-component adhesive, both the first component and the second component are liquid at room temperature (25°C), and it is preferable that the compression loads of the first component and the second component are the same or, even if the compression loads are different, the difference in compression loads is small. By making the compression loads of the first component and the second component the same as each other or close to each other in this way, it becomes easier to uniformly mix the adhesive. Specifically, the difference in compression load between the compression load (N) of the first component and the compression load (N) of the second component is preferably 450 N or less, more preferably 250 N or less, and even more preferably 50 N or less. The method for measuring the compression load is as shown in the examples.

[0072] More specifically, in the two-component adhesive, it is preferable that the first component contains the main agent of the binder and the second component contains the curing agent of the binder. It is preferable to use a curing agent that cures when mixed with the first component. Hereinafter, the configuration of the two-component adhesive will be described in detail, typically when the binder is an epoxy type.

[0073] In a two-component adhesive, the first component contains the main agent but does not necessarily contain the curing agent. On the other hand, the second component contains the curing agent but does not necessarily contain the main agent. However, the second component may contain the main agent as long as it does not react with the curing agent.

[0074] Further, the heat conductive filler is contained in at least one of the first component and the second component, but it is preferably contained in both the first component and the second component. Therefore, it is preferable that the first agent contains a main agent and a thermally conductive filler, and the second agent contains a curing agent and a thermally conductive filler. More preferably, the first agent does not contain a curing agent, and the second agent does not contain a main agent. Therefore, it is more preferable that all of the main agent of the adhesive is contained in the first agent, and all of the curing agent of the adhesive is contained in the second agent.

[0075] Also, the thermally conductive filler is preferably contained in both the first agent and the second agent as described above. Among them, it is more preferable that it is contained in the first agent and the second agent approximately equally. Specifically, the ratio (volume ratio) of the content of the thermally conductive filler in the second agent to the content 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 even more preferably 0.91 or more and 1.1 or less. By distributing the thermally conductive filler approximately equally between the first agent and the second agent, it becomes easier to reduce the difference in compressive load between the first agent and the second agent, and also easier to make the volume ratio of the first agent and the second agent closer to 1.

[0076] Also, the difference in compressive load between the first agent and the second agent can be adjusted by the viscosity of the curing agent such as the epoxy group-containing compound and amine used. For example, specifically, when it is desired to lower the viscosity of the first agent containing an epoxy group-containing compound, a low-viscosity epoxy group-containing compound may be used or the content may be increased. Also, the viscosity may be adjusted to be low by adding a dispersant or a plasticizer.

[0077] The densities of the first agent and the second agent may be closer to each other for easier mixing, and it is preferable that the difference in these densities is smaller. Specifically, the ratio of the density of the first agent to the density of the second agent (also referred to as the density ratio) is preferably 0.7 or more and 1.4 or less, more preferably 0.8 or more and 1.2 or less, and even more preferably 0.9 or more and 1.1 or less. In order to reduce the density ratio, the content of the thermally conductive filler in the first agent and the second agent may be adjusted within the above range. In the two-component type, a dispersant and other additives may be contained in one or both of the first agent and the second agent as necessary. For example, when the thermally conductive filler is contained in both the first agent and the second agent, the dispersant may be contained in both the first agent and the second agent. Also, water may be contained in either the first agent or the second agent, but it is preferably contained in the second agent and not in the first agent.

[0078] In a two-component adhesive, 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 1.05 or more and 2.9 or less. By setting the functional group concentrations of the first agent and the second agent within the above range, when the first agent and the second agent are mixed at a volume ratio of 1:1, the main agent and the curing agent react at an appropriate equivalent ratio, and while having rapid curability, it becomes easier to lengthen the pot life. The ratio of the functional group concentration is more preferably 1.2 or more, further preferably 1.3 or more, even more preferably 1.4 or more, and more preferably 2.6 or less, further preferably 2.1 or less, even more preferably 1.8 or less.

[0079] Note that the functional group concentration is the concentration of functional groups contained in the main agent or the curing agent that can react with the curing agent or the main agent. In an epoxy group-containing compound, the epoxy group becomes the functional group, and the number of epoxy groups per unit amount (g) is the functional group concentration. Also, in amines and thiols, active hydrogen becomes the functional group, and the number of active hydrogens per unit amount (g) is the functional group concentration. For example, in a preferred embodiment, the first agent contains an epoxy group-containing compound and a polyfunctional acrylate compound, does not contain amines and thiols, and the second agent contains either an amine or a thiol and does not contain an epoxy group-containing compound and a polyfunctional acrylate compound. In that case, the total concentration of the epoxy group and the (meth)acryloyl group in the first agent becomes the functional group concentration of the first agent, and the concentration of the active hydrogen of the amine and the thiol in the second agent becomes the functional group concentration of the second agent.

[0080] When the adhesive is a two - component type, it is preferable that the first agent and the second agent are filled in separate containers. Specifically, the first agent may be filled in the first container and the second agent may be filled in the second container. The first container and the second container may be separate or integrated. By integrating the first container and the second container, it becomes easier to supply the container set to the customer. In this specification, the first container filled with the first agent and the second container filled with the second agent may sometimes be collectively referred to as a container set.

[0081] Examples of the container include, but are not limited to, syringes, cartridges, pail cans, drum cans, etc. For example, when filled in a syringe, it is preferable to use a two - liquid parallel - type syringe. As shown in FIG. 1, the two - liquid parallel - type syringe 30 is formed by arranging the first syringe 31 constituting the first container and the second syringe 32 constituting the second container in parallel and integrating them. The first agent 35 and the second agent 36 filled in the syringes 31 and 32 may be discharged from the syringes using the syringes as dispensers and then mixed.

[0082] When using a cartridge, the container set consists of the first cartridge constituting the first container and the second cartridge constituting the second container, and these cartridges may be integrated. Usually, the cartridge is set in a syringe (for example, the first syringe, the second syringe), and the first agent sent out from the first cartridge and the second agent sent out from the second cartridge are discharged from the discharge ports of the first syringe and the second syringe respectively using each syringe as a dispenser and then mixed.

[0083] The mixing of the first agent and the second agent may be performed using a mixer such as a static mixer. For example, as shown in FIG. 1, 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 respective discharge ports 31A, 32A can be mixed inside the mixer 38. The mixture (curable composition) obtained by mixing with the mixer 38 may be discharged from the discharge port 39 of the mixer 38. Each of the syringes 31, 32 preferably has a structure in which the openings of the barrels 33A, 34A filled with the first agent 35 and the second agent 36 respectively are closed by the lid bodies 33B, 34B. In the syringe 30 shown in FIG. 1, the first agent 35 and the second agent 36 are preferably pushed out by a piston (not shown) inserted through the openings after the respective lid bodies 33B, 34B are removed, and discharged from the respective discharge ports 31A, 32A.

[0084] Also, when using pail cans, the container set preferably includes, as shown in FIG. 2, a first pail can 41 that constitutes the first container and is filled with the first agent 45 inside, and a second pail can 42 that constitutes the second container and is filled with the second agent 46 inside. Each of the pail cans 41, 42 includes, for example, container bodies 43A, 44A that are filled with the first agent 45 and the second agent 46 inside and have openings, and lid bodies 43B, 44B that close the openings of the respective container bodies 43A, 44A.

[0085] (Method for preparing an adhesive) When the adhesive of the present invention is a two-component type, the first agent and the second agent may each be obtained by mixing the components constituting the first agent and the second agent respectively. Similarly, when it is a one-component type, the adhesive may be obtained by mixing the respective components constituting the adhesive. The method of mixing the respective components is not particularly limited. For example, additives such as a heat conductive filler that is blended as necessary and a dispersant that is blended as necessary may be added to a binder, and then it may be prepared by stirring or kneading.

[0086] Alternatively, the thermally conductive filler may be surface-treated with a dispersant and then mixed with a binder. By being surface-treated with a dispersant in advance, the thermally conductive filler will be surface-modified with the dispersant in advance. Then, the thermally conductive filler surface-modified in advance may be mixed with a binder to prepare an adhesive. The method of performing surface treatment in advance using a dispersant is not particularly limited and may be performed by known methods. For example, wet treatment methods, dry treatment methods, etc. can be used. In the wet treatment method, for example, the thermally conductive filler is added and mixed in a treatment liquid in which a dispersant is dispersed or dissolved in a solvent, and then dried, heat-treated, washed, etc., so that the dispersant is bound or adhered to the surface of the thermally conductive filler. The dry treatment method is a method of performing surface treatment without using a dispersion medium. Specifically, it is a method in which a dispersant is mixed with the thermally conductive filler and stirred with a mixer or the like, and then heat-treated to bind or adhere the dispersant to the surface of the thermally conductive filler.

[0087] [Thermally Conductive Member] The adhesive of the present invention may be used as a thermally conductive member. The adhesive of the present invention becomes a thermally conductive member by curing. The thermally conductive member of the present invention includes a polymer matrix and a thermally conductive filler. The polymer matrix is formed by curing a binder, and the thermally conductive filler is dispersed in the polymer matrix and held by the polymer matrix. Therefore, for example, when the binder is epoxy-based, the polymer matrix is composed of a cured epoxy resin. The thermally conductive member may be disposed and used between two members such as a heat-generating body and a heat-radiating body. Examples of the heat-generating body include electronic components that generate heat such as batteries. Examples of the heat-radiating body include cooling members such as a housing, a heat sink, and a cooling plate.

[0088] Note that the details of the thermally conductive filler in the thermally conductive filler are the same as those in the thermally conductive filler in the above adhesive, so the description thereof is omitted. Also, the binder for forming the polymer matrix is the same as the binder in the above adhesive, so the description thereof is omitted. The same applies to the dispersant and other additives. However, in the above, the content ratio of the binder and the content ratio of the thermally conductive filler were described based on the volume of the entire adhesive. Since the thermally conductive member is formed from the adhesive, the content ratio based on the volume of the entire adhesive described above can be regarded as the content ratio based on the volume of the entire thermally conductive member in the thermally conductive member.

[0089] [Applications] The adhesive and the thermally conductive member of the present invention can be used in various applications. For example, they can be used in various electronic device applications such as battery assemblies such as lithium-ion battery (LiB) assemblies, power electronics devices, electronic packaging, LEDs, solar cells, and electrical grids. Among these, it is preferably used in battery assemblies, and more preferably used in LiB assemblies. Therefore, in a preferred embodiment of the present invention, a battery assembly including the above-described thermally conductive member is provided. Note that battery assemblies such as LiB assemblies can be preferably used for automobiles.

[0090] In battery assembly applications, the adhesive and the thermally conductive member of the present invention are preferably used as a gap material for the battery assembly. Also, in one aspect, the adhesive and the thermally conductive member of the present invention are preferably used in battery modules, and more preferably used as a gap material for battery modules. Hereinafter, an example in which the thermally conductive member of the present invention is applied to a battery module will be described.

[0091] The battery module includes a spacer made of a heat-conductive member, a plurality of battery cells, and a module housing that houses the plurality of battery cells. The spacer is disposed inside the module housing. The spacer made of a heat-conductive member is filled between the battery cells and between the battery cells and the module housing, and the filled spacer is in close contact with the battery cells and the module housing. Thereby, the spacer between the battery cells has a function of maintaining the separated state between the battery cells. Also, the spacer between the battery cell and the module housing is in close contact with both the battery cell and the module housing and has a function of transmitting the heat generated in the battery cell to the module housing.

[0092] FIG. 3 shows a specific configuration of the battery module. FIG. 4 shows a specific configuration of each battery cell. As shown in FIG. 3, a plurality of battery cells 11 are disposed inside the battery module 10. Each battery cell 11 is encapsulated by being laminated inside a flexible exterior film, and the overall shape is a flat body with a thickness thinner than the height and width. As shown in FIG. 4, in such a battery cell 11, the positive electrode 11a and the negative electrode 11b are exposed to the outside, and the central portion 11c of the flat surface is formed thicker than the crimped end portion 11d.

[0093] As shown in FIG. 3, the battery cells 11 are arranged such that their flat surfaces face each other. In the configuration of FIG. 3, the spacer 13 is not filled so as to cover the entirety of the plurality of battery cells 11 stored inside the module housing 12. The spacer 13 is filled so as to fill a gap existing in a part (bottom side part) inside the module housing 12. The spacer 13 is filled between the battery cells 11 and between the battery cells 11 and the module housing 12, and is in close contact with the surface of the battery cells 11 in this part and the inner surface of the module housing 12.

[0094] The spacer material 13 filled between the battery cells 11 is adhered to the surfaces of both battery cells 11. However, since the spacer material 13 itself has appropriate elasticity and flexibility, even when an external force that displaces the distance between the battery cells 11 is applied, it can relieve the strain deformation caused by the external force. Therefore, the spacer material 13 has a function of maintaining the separated state between the battery cells 11. The spacer material 13 filled in the gap between the battery cell 11 and the inner surface of the module housing 12 is also closely adhered to the surface of the battery cell 11 and the inner surface of the module housing 12. As a result, the heat generated inside the battery cell 11 is transmitted to the inner surface of the module housing 12 that is in close contact with the other surface of the spacer material 13 via the spacer material 13 adhered to the surface of the battery cell 11.

[0095] The formation of the spacer material 13 in the battery module 10 may be performed by applying a liquid adhesive using a general dispenser and then curing the liquid adhesive. Further, as described above, since the adhesive of the present invention has a low viscosity, the workability during the formation of the spacer material 13 is improved. When forming the spacer material 13, it is preferable to use a two-component adhesive as described above. The two-component type is easy to store, and it is difficult to cure during the application work with a dispenser if it is mixed immediately before use, and it can be cured quickly after application. Further, the application with a dispenser is also preferable in that the liquid adhesive can be filled to a relatively deep part inside the housing 12 of the battery module 10.

[0096] The spacer 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. Also, by sufficiently covering the battery cell with a large calorific value, the heat dissipation efficiency becomes good. On the other hand, by setting it to 40% or less, the heat generated from the battery cell 11 can be efficiently dissipated, and an increase in weight and deterioration of workability can be prevented. Further, in order to improve the heat dissipation efficiency, it is preferable to cover the side where the electrodes 11a and 11b of the battery cell 11 are located with the spacer 13, and it is more preferable to cover the entire electrodes 11a and 11b with the spacer 13. As described above, the battery module 10 can release the heat generated from the battery cell 11 to the module housing 12 via the spacer 13.

[0097] The spacer 13 is also preferably used for a battery pack that includes a plurality of battery modules 10 therein. Generally, a battery pack includes a plurality of battery modules 10 and a housing of the battery pack that houses the plurality of battery modules 10. In the battery pack, the spacer 13 can be provided between the battery module 10 and the housing of the battery pack. Thereby, the heat released to the module housing 12 as described above can be further released to the housing of the battery pack, enabling effective heat dissipation.

[0098] In the above description, an example in which the battery assembly is a battery module or a battery pack including the battery module has been described, but it may also be applied to a battery assembly that does not have a battery module, and for example, it is also preferably applied to a battery assembly having a cell-to-pack structure.

[0099] A schematic diagram of a battery assembly having a cell-to-pack structure is shown in FIG. 5. A battery assembly 20 having a cell-to-pack structure includes a plurality of battery cells 21 and a housing of the battery pack. The plurality of battery cells 21 are adhered to a base member 25 constituting the housing of the battery pack via a spacer 23 made of a heat-conductive member (a cured product of an adhesive). The base member 25 may constitute a cooling plate or the like. Note that the formation of the spacer 23 in the battery assembly 20 may be performed in the same manner as the formation of the spacer 13 in the battery module, for example, using a general dispenser. Since the adhesive of the present invention has a low viscosity, the workability when forming the spacer 23 is also improved. Further, although the adhesive of the present invention has fast-curing properties, it can reduce the compressive load and increase the pot life in the initial stage of curing. Therefore, even in a battery assembly having a cell-to-pack structure, the battery cells 21 can be adhered to the base member 25 with high workability.

Example

[0100] Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0101] [Thermal conductivity] The thermal conductivities of the first agent and the second agent of the adhesive were determined by a method of measuring the thermal resistance using a measuring device conforming to ASTM D5470-06. Specifically, the adhesive was disposed in an amount more than the thickness at the time of measurement so as to cover the measurement die on the heating element side, and then sandwiched between the heat sinks and compressed with a load of 30 psi until the thicknesses of the adhesive became 1.0 mm, 1.5 mm, and 2.0 mm, and the thermal resistances of the respective thicknesses were measured. The thickness can be adjusted with a spacer. For these three thermal resistance values, a graph with the thickness on the horizontal axis and the thermal resistance value on the vertical axis was created, and an approximate straight line passing through three points was obtained by the least squares method. Then, the slope of the approximate straight line is the thermal conductivity. The thermal resistance was measured at 80 °C using an LW-9389 manufactured by Long Win Science and Technology Corporation. The area of the measurement die was set to 1 inch × 1 inch.

[0102] [Compressive load] 2 g of the adhesive prepared as per the formulation was placed on an aluminum foil measuring 50 mm × 50 mm × 12 μm thick, wrapped with the aluminum foil, and placed in a constant temperature bath at 35 °C for 6 minutes to obtain a measurement sample. Subsequently, a jig was pressed against the measurement location so that the load value reached 3.6 kg without placing the sample, and the point 10 mm away from there was set as the measurement start position (zero point). The compressive load of the measurement sample was measured under the conditions shown below. The first agent and the second agent were also measured in the same manner. Test speed: 60 mm / second Jig size: 3 cm φ Result reading value: The result at a displacement of 8.80 mm was taken as the compressive load value. Test environment: 25 °C, 50% RH Based on the obtained compressive load values, evaluation was carried out in the following four levels. Note that the compressive load indicates the compressive load at the initial stage of curing, and the lower the value, the easier the temporary adhesion and the longer the pot life tend to be. (Evaluation criteria) AA: 500 N or less A: 800 N or less B: More than 800 N and 1000 N or less C: More than 1000 N and 1500 N or less D: More than 1500 N

[0103] [Adhesive strength (after 1 hour)] The adhesive strength of the cured adhesive at 18°C (after 1 hour) was measured by the following method in accordance with DIN EN 1465. First, two PET plates (product name: "PET-6010", manufactured by Takiron Shear Eye Co., Ltd.) with a width of 25 mm, a length of 100 mm, and a thickness of 2 mm were prepared. Then, on the longitudinal end of one plate, an adhesive was applied over the entire width of the plate with a length of 5 mm so that the thickness after curing was 1 mm. After that, the longitudinal end of the other plate was overlapped on the applied adhesive, and in this state, it was left for 1 hour in an environment of 18°C and 50% RH to cure the adhesive and obtain a measurement sample. The measurement sample was formed by overlapping two PET plates over the entire width for a length of 5 mm, and the films were adhered to each other through the cured product of the adhesive (size: 25 mm × 5 mm, thickness 1 mm) at the overlapping part, and had a size of 25 mm in width and 195 mm in length.

[0104] [Adhesive strength (after 18 hours)] The adhesive strength (after 18 hours) was measured by the same measurement method as that for the adhesive strength (after 1 hour), except that it was left for 18 hours after the application of the adhesive.

[0105] [Gelation time] Using the sample obtained by mixing the first agent and the second agent, the storage modulus G' and the loss modulus G'' were measured with a rheometer. Specifically, using a rheometer MCR-302e manufactured by Anton Paar, while generating strain at 25°C using a Peltier plate, with a frequency of 1 Hz, the changes in the storage modulus G' and the loss modulus G'' of each sample were measured continuously for 120 minutes. Then, the time from the start of the measurement until the gelation point where the storage modulus G' (storage elastic modulus) and the loss modulus G'' (loss elastic modulus) became equal was defined as the gelation time. The measurement was started immediately after mixing the first agent and the second agent.

[0106] [Storage modulus G' (after 15 minutes)] Using a rheometer MCR-302e manufactured by Anton Paar, while generating strain at 25°C using the Peltier plate, with a frequency of 1 Hz, the measurement was carried out, and the storage modulus G' 15 minutes after the start of the measurement was recorded. The measurement method and conditions were the same as those for the above gelation time.

[0107] [Elastic modulus G’’ (after 15 minutes)] Using a rheometer MCR-302e manufactured by Anton Paar, while generating strain at 25 °C using a Peltier plate, the measurement was carried out at a frequency of 1 Hz, and the elastic modulus G’’ 15 minutes after the start of the measurement was recorded. The measurement method and conditions were the same as those for the gelation time described above.

[0108] [Storage elastic modulus (after 60 minutes)] Using a rheometer MCR-302e manufactured by Anton Paar, while generating strain at 25 °C using a Peltier plate, the measurement was carried out at a frequency of 1 Hz, and the elastic modulus G’ 60 minutes after the start of the measurement was recorded. The measurement method and conditions were the same as those for the gelation time described above.

[0109] [Examples 1 to 6, Comparative Examples 1 to 3] According to the formulations in Tables 1 and 2, each component was mixed to prepare the First Agent and the Second Agent. The adjusted First and Second Agents were filled into 50 cc two-component parallel cartridges each, and using a static mixer, they were mixed at a volume ratio of 1:1 at room temperature to obtain an adhesive. Each physical property value of the obtained adhesive was determined, and an evaluation test was also carried out.

[0110] Each component used in each example and comparative example was as follows. (Epoxy group-containing compound) Bisphenol F type epoxy resin: Trade name “jER806”, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 165 g / eq, molecular weight 330, viscosity (25 °C) 2000 mPa·s (catalog value) Polyfunctional epoxy resin: Trade name “EX-321”, manufactured by Nagase ChemteX Corporation, molecular weight 280, epoxy equivalent 140 g / eq, viscosity (25 °C) 130 mPa·s (catalog value), trimethylolpropane polyglycidyl ether Monofunctional epoxy resin: Aliphatic glycidyl ether (aliphatic alcohol is C 12-14 ), trade name “Epogoseal ML”, manufactured by Yokkaichi Gosei Co., Ltd., epoxy equivalent 282 g / eq, number of functional groups 1, molecular weight 282 Glycidyl ether: Trade name "Denacol EX146", manufactured by Nagase ChemteX Corporation, molecular weight 225, 4-t-butylphenyl glycidyl ether, epoxy equivalent 225 g / eq

[0111] (Polyfunctional acrylate compound) Dipentaerythritol hexaacrylate: Trade name "DPHA", manufactured by Daicel Ornic Co., Ltd., molecular weight 520 (Amine curing agent) Trimethylolpropane poly(oxypropylene) triamine: Trade name "T-403", manufactured by Huntsman Corporation, molecular weight 440, viscosity (25 °C) 0.7 Pa·s (catalog value), active hydrogen equivalent 73.3 g / eq Poly(oxypropylene) diamine: Trade name "D-230", manufactured by Huntsman Corporation, molecular weight 230, viscosity (25 °C) 0.1 Pa·s (catalog value) Poly(oxypropylene) diamine: Trade name "D-400", manufactured by Huntsman Corporation, molecular weight 430, active hydrogen equivalent 107.5 g / eq, viscosity (25 °C) 0.3 Pa·s (catalog value) Polyamide amine: Trade name "ancamide506", manufactured by Evonik Industries AG, active hydrogen equivalent 110 g / eq, viscosity (25 °C) 0.3 Pa·s, amide amine Phenalkamine type Mannich base: Trade name "NC-540", manufactured by Cardolite Japan Co., Ltd., active hydrogen equivalent 85 g / eq, viscosity (25 °C) 2 Pa·s Amide amine: Trade name "TD-960", manufactured by DIC Corporation, active hydrogen equivalent 77 g / eq, viscosity (25 °C) 75 Pa·s (catalog value) (Thixotropy imparting agent) Amide powder: Trade name "6650", manufactured by Kusumoto Chemicals, Ltd. (Dispersant) Polymeric dispersant (acid group-containing copolymer) (Thermally conductive filler) Aluminum hydroxide 1: Average particle size 1 μm Aluminum hydroxide 2: Average particle size 10 μm Aluminum hydroxide 3: Average particle size 50 μm Aluminum hydroxide 4: Average particle size 105 μm Catalyst Bisphenol F: Trade name "Bisphenol F", manufactured by Honshu Chemical Co., Ltd. Pure water

[0112] [Table 1]

[0113] [Table 2]

[0114] As is clear from the above examples, the curable thermally conductive adhesive that satisfies the requirements of the present invention has an appropriate gelation time, and the adhesive strength can be developed to the extent that it can be temporarily adhered 1 hour after mixing and applying each component. In addition, since the compression load of the adhesive immediately after mixing is low and the viscosity is low, it can also be bonded to the adherend in a sufficiently compressed state. And, 18 hours after mixing and applying each component, sufficient adhesive strength could be developed, so it was possible to obtain an adhesive with fast curing properties and a long pot life. On the other hand, in Comparative Example 1, because the gelation time was too short, the compression load of the adhesive was high and the viscosity was high, and it was found that the pot life became short as a result. In addition, for the adhesive prepared in Comparative Example 2, since the gelation time was too long or the storage elastic modulus 60 minutes after mixing and applying each component was too low, the curing of the adhesive did not proceed sufficiently, and sufficient adhesive strength could not be developed even 18 hours after mixing and applying each component. Furthermore, for the adhesive prepared in Comparative Example 3, since the storage elastic modulus 60 minutes after mixing and applying each component was too low, the curing of the adhesive did not proceed sufficiently, and sufficient adhesive strength could not be developed even 18 hours after mixing and applying each component. [Explanation of Reference Numerals]

[0115] 10 Battery module 11, 21 Battery cells 12 Housing of battery module (module housing) Gap material between 13 and 23 20 Battery assembly 25 Base member 30 Syringe 31 First syringe 31A Discharge port of the first syringe 32 Second syringe 32A Discharge port of the second syringe 33A, 34A Barrel 33B, 34B Lid of the barrel 35, 45 First agent 36, 46 Second agent 38 Mixer 39 Discharge port of the mixer 41 First pail 42 Second pail 43A, 44A Container body with an opening 43B, 44B Lid for closing the opening of the container body

Claims

1. A curable thermally conductive adhesive comprising a curable composition including a curable binder and a thermally conductive filler, When the rheometer was used at a constant temperature of 25° C., the gel point at which the storage modulus and the loss modulus are equal was confirmed 5 to 60 minutes after the start of the rheometer measurement, and the storage modulus at 25° C. was 9.0×10 or less after 60 minutes had elapsed since the start of the rheometer measurement. ５ A curable thermally conductive adhesive having a viscosity of 100 Pa or more.

2. When measured with the rheometer, the loss modulus of the curable thermally conductive adhesive at 25° C. after 15 minutes from the start of the rheometer measurement was 3.0×10 ５ The curable thermally conductive adhesive of claim 1 , having a viscosity of 0.05 Pa or less.

3. The curable thermally conductive adhesive according to claim 1 or 2, wherein the binder comprises an epoxy group-containing compound.

4. 3. The curable thermally conductive adhesive of claim 1 or 2, wherein the binder comprises at least one of an amine and a thiol.

5. The curable thermally conductive adhesive of claim 1 or 2, wherein the binder comprises an epoxy group-containing compound and an amine.

6. The curable thermally conductive adhesive of claim 3 , wherein the epoxy group-containing compound comprises a monofunctional epoxy group-containing compound.

7. 3. The curable thermally conductive adhesive of claim 1 or 2, wherein the binder comprises a Mannich base.

8. The curable thermally conductive adhesive according to claim 1 or 2, wherein the curable composition comprises a multifunctional acrylate compound, an epoxy group-containing compound, and an amine.

9. 3. The curable thermally conductive adhesive according to claim 1 or 2, wherein the equivalent ratio, which is the ratio of the equivalent of the active hydrogen of the curing agent to the equivalent of the functional group of the component constituting the main agent contained in the curable composition, is 1.05 or more and 2.9 or less.

10. A supply form of the curable thermally conductive adhesive according to claim 1 or 2, A supply form of the curable thermally conductive adhesive in which a first part containing the main agent of the binder and a second part containing a curing agent that hardens when mixed with the first part are filled in separate containers.

11. 11. The supply form of the curable thermally conductive adhesive according to claim 10, wherein the difference between the viscosity of the first part and the compressive load of the second part is 450 N or less.

12. 11. The supply form of the curable thermally conductive adhesive according to claim 10, wherein the ratio of the functional group concentration of the second part to the functional group concentration of the first part is 1.05 or more and 2.9 or less.

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