Curable thermally conductive adhesive and supply form thereof

Abstract

A curable thermally conductive adhesive comprising a curable composition containing a curable binder and a thermally conductive filler, the curable thermally conductive adhesive being characterized in that: when a rheometer measurement is performed at a constant temperature of 25 DEG C, the gelatinization point at which the storage modulus and the loss modulus are equal is determined at 5-60 minutes when the rheometer measurement begins; and the storage modulus at 25 DEG C 60 minutes after the start of the measurement by the rheometer is 9.0 * 105 Pa or more.

Description

Technical Field

[0001] The present invention relates to a curable thermally conductive adhesive and a thermally conductive member used in electronic devices such as battery packs. Background Art

[0002] Thermally conductive compositions are placed between, for example, a heating element and a heat sink to transfer heat generated by the heating element and dissipate it away from the heat sink. Thermally conductive compositions are typically curable and are often cured after filling, resulting in their use as a cured product. Thermally conductive compositions play a vital role in numerous electronic device applications, including battery components such as lithium-ion batteries (LiBs) used in electric vehicles (EVs), power electronics, electronic packaging, LEDs, solar cells, and power transmission networks.

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

[0004] Prior art literature

[0005] Patent Literature

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

[0007] Problems to be solved by the invention

[0008] However, as the number of EVs produced in the future increases, improving the room temperature curing properties of thermally conductive compositions is one of the important issues in order to improve their productivity. Assembly manufacturers attach importance to temporary bonding strength during the process and require that if a certain time is exceeded, the adhesive can be moved within the process, that is, it can be temporarily fixed or placed vertically. During this temporary bonding, it is also necessary to follow the height differences and depressions between components. During the usable period, it is important to be able to spread the resin easily on the substrate with a low load. For example, it is required that the adhesive can be placed vertically within 1 hour and can be easily spread on the substrate with a low load during the usable period.

[0009] In addition, assembly manufacturers are considering shortening assembly time, for example, by enabling temporary fixing after 1 hour. On the other hand, it is envisioned that the bonded parts will be transported after 18 hours. Balancing the adhesive strength performance in a short period of time, or after one day, and the usable time is also an important issue when considering efficiency and workability.

[0010] Patent Document 1 uses polyamide to improve rapid curing due to concerns about the health risks of adding acrylates. Polyamide has a low molecular weight, but its viscosity increases due to interactions with other materials. Therefore, even though rapid curing is possible, a long pot life cannot be achieved.

[0011] Therefore, an object of the present invention is to provide a curable thermally conductive adhesive that has low viscosity, fast curing properties, and can extend the usable time.

[0012] Means of solving problems

[0013] The present inventors conducted intensive studies and found that the above-mentioned problems can be solved by adjusting the gelation point to be confirmed at 5 minutes or more and 60 minutes or less from the start of rheometer measurement and adjusting the storage modulus at 25°C to be a certain value or more 60 minutes after the start of rheometer measurement.

[0014] That is, the present invention provides the following solutions [1] to

[13] .

[0015] [1] A curable thermally conductive adhesive, comprising a curable composition containing a curable binder and a thermally conductive filler, wherein when a rheometer is measured at a constant temperature of 25°C, a gel point at which the storage modulus and the loss modulus are equal is confirmed at a time of 5 minutes or more and 60 minutes from the start of the rheometer measurement, and the storage modulus at 25°C 60 minutes after the start of the rheometer measurement is 9.0×10 5 Pa or above.

[0016] [2] The curable thermally conductive adhesive according to [1], when measured by the rheometer, has a loss modulus of 3.0×10 5 Below Pa.

[0017] [3] The curable thermally conductive adhesive according to [1] or [2], wherein the adhesive contains an epoxy group-containing compound.

[0018] [4] The curable thermally conductive adhesive according to any one of [1] to [3], wherein the adhesive contains at least one of an amine and a thiol.

[0019] [5] The curable thermally conductive adhesive according to any one of [1] to [4], wherein the adhesive contains an epoxy group-containing compound and an amine.

[0020] [6] The curable thermally conductive adhesive according to [3] or [5], wherein the epoxy-containing compound comprises a monofunctional epoxy-containing compound.

[0021] [7] The curable thermally conductive adhesive according to any one of [1] to [6], wherein the adhesive contains a Mannich base.

[0022] [8] The curable thermally conductive adhesive according to any one of [1] to [7], wherein the curable composition contains a multifunctional acrylate compound, an epoxy group-containing compound, and an amine.

[0023] [9] The curable thermally conductive adhesive according to any one of [1] to [8], wherein the equivalent ratio of the active hydrogen of the curing agent to the equivalent of the functional groups of the components constituting the main agent contained in the curable composition, i.e., the equivalent ratio, is 1.05 or more and 2.9 or less.

[0024]

[10] A supply form of a curable thermally conductive adhesive, which is the supply form of the curable thermally conductive adhesive according to claim 1 or 2,

[0025] A first component containing a main component of the adhesive and a second component containing a curing agent that can be cured by mixing with the first component are filled in separate containers.

[0026]

[11] The supply form of the curable thermally conductive adhesive as described in

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

[0027]

[12] The supply form of the curable thermally conductive adhesive as described in

[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.

[0028]

[13] Use of the curable thermally conductive adhesive described in any one of [1] to

[10] above as at least one of a gap member between battery cells, a gap member between a battery cell and a module housing, a gap member between a battery module and a battery pack housing, and a gap member between a battery cell and a battery pack housing.

[0029] Effects of the Invention

[0030] According to the present invention, a curable thermally conductive adhesive can be provided that has rapid curing properties at low viscosity and can extend the usable time. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram showing a container kit according to one embodiment.

[0032] Figure 2 This is a schematic diagram showing a container kit according to another embodiment.

[0033] Figure 3It is a perspective view showing a typical structure of a battery module according to the present invention.

[0034] Figure 4 It is a perspective view showing a typical structure of a battery cell included in a battery module.

[0035] Figure 5 It is a perspective view showing a battery assembly having a cell-to-pack structure. DETAILED DESCRIPTION

[0036] [Curing thermally conductive adhesive]

[0037] The curable thermally conductive adhesive of the present invention will be described in detail below.

[0038] 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 modulus and loss modulus at 25°C are measured using a rheometer (hereinafter referred to as the "rheometer measurement"), a gelation point (hereinafter referred to as the "gelation point"), at which the storage modulus and loss modulus become equal, is determined between 5 and 60 minutes after the start of the measurement. Furthermore, the storage modulus at 25°C, 60 minutes after the start of the measurement, is 9.0 × 10 5 Pa or above.

[0039] <Gel point>

[0040] If the gel point is confirmed within less than 5 minutes after the start of the rheometer measurement, the usable time will be shortened, and the adhesive will immediately become highly viscous after being applied to the substrate, making it difficult to spread the adhesive on the substrate. In addition, if the gel point is confirmed more than 60 minutes after the start of the rheometer measurement, the excellent bonding strength will be slow to develop, and the adhesive will not have fast curing properties. From these viewpoints, the gel point is preferably confirmed at least 5 minutes and no more than 50 minutes after the start of the rheometer measurement, and more preferably at least 10 minutes and no more than 40 minutes after the start of the rheometer measurement.

[0041] Here, the gel point refers to the point at which the storage modulus and loss modulus of the adhesive are equal when measured by a rheometer at 25° C. As a rheometer, for example, the "MCR-302e" rheometer manufactured by Anton Paar can be used.

[0042] The method for measuring the time required to confirm the gelation point (hereinafter also referred to as “gelation time”) is as described in the Examples.

[0043] The gel point can be adjusted to fall within the above-specified range by, for example, appropriately adjusting the types and amounts of the main component and curing agent in the adhesive component.

[0044] Storage modulus

[0045] If the storage modulus at 25°C (hereinafter also referred to as "modulus G'(60)") is less than 9.0×10 5 Pa, it is difficult for the adhesive to show excellent adhesion. From this point of view, the modulus G'(60) is preferably 9.2×10 5 Pa or more, more preferably 1.0×10 6 Pa or more. In addition, the upper limit of the modulus G'(60) is not particularly limited, but is preferably 1.0×10 7 Pa or less, more preferably 8.0×10 6 Pa or less, more preferably 5.0×10 6 Below Pa.

[0046] In addition, the modulus G'(60) can be obtained by the measurement method described in the Examples.

[0047] The adhesive of the present invention preferably has a loss modulus (hereinafter also referred to as "modulus G" (15)") at 25°C of 3.0×10 5 Pa or less, more preferably 2.5×10 5 Pa or less, more preferably 2.0×10 5 Pa or less. By making the modulus G'' (15) below the upper limit, the adhesive will not cure too quickly, and the usable time will be easily extended. In addition, for example, the adhesive strength after 18 hours will easily become above a certain value. On the other hand, from the perspective of ensuring a certain degree of rapid curing of the adhesive, the modulus G'' (15) is preferably 2.0×10 3 Pa or more, more preferably 2.2×10 3 Pa or more, more preferably 2.5×10 3 Pa and above.

[0048] In addition, the modulus G'' (15) can be obtained by the measurement method described in the Examples.

[0049] The adhesive of the present invention preferably has a storage modulus (hereinafter referred to as "modulus G'(15)") of 2.5×10 6 Pa or less, more preferably 2.0×10 6 Pa or less, more preferably 1.7×10 6Pa or less. By making the modulus G'(15) below the upper limit, the curing of the adhesive will not be too fast, and the usable time can be easily extended. In addition, for example, it is easy to make the adhesive strength after 18 hours to be above a certain value. On the other hand, from the perspective of ensuring a certain degree of rapid curing of the adhesive, the modulus G'(15) is preferably 5.0×10 2 Pa or more, more preferably 8.0×10 2 Pa or more, more preferably 1.0×10 3 Pa and above.

[0050] In addition, the modulus G'(15) can be obtained by the measurement method described in the Examples.

[0051] Furthermore, the modulus G'(60), modulus G''(15), and modulus G'(15) can be adjusted to fall within the above-specified ranges by, for example, appropriately adjusting the types and amounts of the main agent and curing agent of the adhesive component. Furthermore, the modulus G'(60) and modulus G'(15) can also be easily increased by improving curability.

[0052] Thermal conductivity

[0053] The adhesive of the present invention preferably has a cured product with a thermal conductivity of 1.3 W / (m·K) or greater, more preferably 1.5 W / (m·K) or greater, and even more preferably 1.6 W / (m·K) or greater. By ensuring that the cured product has a thermal conductivity above these lower limits, the adhesive exhibits excellent thermal conductivity. Therefore, when used in, for example, a battery cell assembly, heat generated by the battery cells can be efficiently transferred to the module housing or battery pack via the cured adhesive (thermally conductive component), thereby suppressing excessive increases in the battery cell temperature. While the higher the thermal conductivity, the better, practically speaking, it is, for example, 7.0 W / (m·K) or less.

[0054] Thermal conductivity can be measured according to a method conforming to ASTM D5470-06.

[0055] Specifically, the adhesive is configured to be thicker than the thickness during measurement in a manner that covers the measuring die head on the heating element side, and then it is clamped with a radiator, and the thickness of the adhesive is compressed to 1.0mm, 1.5mm, and 2.0mm with a load of 30psi, and the thermal resistance under each thickness is measured. The thickness can be adjusted with a gasket. For the values ​​of these three thermal resistances, a graph is made with the horizontal axis being the thickness and the vertical axis being the thermal resistance value, and an approximate straight line at three points is obtained by the least squares method. In addition, the slope of the approximate straight line is used as thermal conductivity.

[0056] Adhesion strength

[0057] The adhesive of the present invention preferably has an adhesive strength (hereinafter referred to as "Adhesion Strength 1") of 0.03 MPa to 0.7 MPa, more preferably 0.05 MPa to 0.5 MPa, and even more preferably 0.08 MPa to 0.3 MPa, one hour after mixing the components. When Adhesion Strength 1 is above this lower limit, the minimum adhesive strength required for temporary component fastening can be ensured. Furthermore, when Adhesion Strength 1 is below this upper limit, components can be easily removed after temporary fastening, for example, to adjust their position.

[0058] Furthermore, the adhesive strength of the adhesive of the present invention 18 hours after mixing the components (hereinafter referred to as "Adhesion Strength 2") is preferably 0.8 MPa or greater, more preferably 0.9 MPa or greater, and even more preferably 1.2 MPa or greater. When Adhesion Strength 2 is above this lower limit, the adhesive is fully cured, and for example, during transportation of components bonded via the adhesive, even when vibrations are generated during transportation, the components can be prevented from peeling. While there is no particular upper limit for Adhesion Strength 2, it is practically 5 MPa or less, preferably 3 MPa or less, and more preferably 2 MPa or less.

[0059] In addition, each of the above-mentioned adhesive forces can be obtained by the measurement methods described in the Examples.

[0060] Adhesive

[0061] The adhesive of the present invention comprises a curable adhesive. The curable adhesive may be thermosetting, light-curing, or moisture-curing, but is preferably thermosetting. Furthermore, the adhesive may be either a single-component curing type or a two-component curing type, but is preferably a two-component curing type.

[0062] Two-component curing is a method where a first component containing a base component and a second component containing a curing agent are mixed. Curing begins simply by mixing the first and second components. Therefore, in a two-component curing system, a curing agent that cures by mixing with the base component of the first component can be used. Alternatively, a curing agent that cures at room temperature (25°C) can be used after mixing with the base component of the first component.

[0063] The adhesive is preferably any of urethane, silicone, acrylic, epoxy or organic polymers having a hydrolyzable silyl group, with epoxy being preferred. Use of these specific adhesives can easily impart rapid curing properties to the adhesive or extend its usable life.

[0064] The binder may be used alone or in combination of two or more.

[0065] Here, examples of the urethane adhesive include an adhesive composed of a polyol compound as a main agent and a polyisocyanate compound as a curing agent.

[0066] The silicone adhesive may be either a condensation-curable silicone resin or an addition-curable silicone resin, with addition-curable silicone resins being preferred. Addition-curable silicone resins may be composed of a silicone resin constituting a base resin and a curing agent for curing the base resin. For example, in the case of an addition-curable silicone resin, an organopolysiloxane having an alkenyl group may be used as the base resin, and an organohydrogenpolysiloxane may be used as the curing agent.

[0067] The epoxy adhesive can be composed of an epoxy group-containing compound as a main component and a curing agent.

[0068] Acrylic adhesives can be any component capable of forming an acrylic polymer upon curing. Examples include alkyl (meth)acrylates, hydroxyalkyl (meth)acrylates, (meth)acrylic acid, (meth)acrylamides, and urethane (meth)acrylates. Acrylic adhesives may also contain vinyl monomers copolymerizable with the aforementioned acrylic compounds. Furthermore, at least a portion of the acrylic adhesive may be a polymer of an acrylic compound or a copolymer of an acrylic compound and a vinyl monomer. Furthermore, the acrylic adhesive may be a monofunctional or multifunctional acrylate compound.

[0069] Organic polymers containing hydrolyzable silyl groups have hydrolyzable silyl groups. Moisture, such as moisture, hydrolyzes these silanol groups to form silanol groups. These groups can then undergo condensation polymerization, either with each other or with the hydrolyzable silyl groups, to form siloxane bonds. This allows the organic polymer to form a crosslinked structure and cure, yielding a rubbery elastomer. A silanol group refers to a hydroxyl group (Si-OH) directly bonded to a silicon atom. The hydrolyzable silyl group is preferably an alkoxysilyl group, specifically trimethoxysilyl, dimethoxysilyl, triethoxysilyl, and diethoxysilyl. Alternatively, examples of organic polymers include polyethers such as polyoxyalkylenes.

[0070] Hereinafter, the case of using an epoxy adhesive as the adhesive will be described in detail.

[0071] (Epoxy-containing compounds)

[0072] As mentioned above, when the adhesive is epoxy-based, it may contain an epoxy-containing compound. By using an epoxy-containing compound, the adhesive strength can be easily adjusted to an appropriate range. The epoxy-containing compound can be any compound having one or more epoxy groups. The epoxy-containing compound can be a polyfunctional epoxy-containing compound having two or more epoxy groups, or a monofunctional epoxy-containing compound having one epoxy group.

[0073] The adhesive of the present invention preferably contains at least a polyfunctional epoxy-containing compound. By containing the polyfunctional epoxy-containing compound, the reaction rate between the main agent and the curing agent is increased, the time to gel point is shortened, and rapid curing is easily exhibited.

[0074] In addition to the polyfunctional epoxy-containing compound, the adhesive may also contain a monofunctional epoxy-containing compound. By further incorporating a monofunctional epoxy-containing compound, the reaction rate between the base and curing agent becomes moderate, thereby easily extending the pot life and reducing the initial viscosity. Furthermore, it can prevent the gel point from being observed too quickly.

[0075] When a polyfunctional epoxy resin and a monofunctional epoxy resin are used in combination, the mass ratio of the monofunctional epoxy resin to the polyfunctional epoxy resin (monofunctional / polyfunctional) is preferably 10 / 90 or more and 90 / 10 or less, more preferably 15 / 85 or more and 75 / 25 or less, further preferably 20 / 80 or more and 70 / 30 or less, and even more preferably 25 / 75 or more and 60 / 40 or less.

[0076] Examples of the polyfunctional epoxy-containing compound include bifunctional and trifunctional compounds, with bifunctional epoxy-containing compounds being preferred. Specific examples of the polyfunctional epoxy-containing compound include epoxy resins having an aromatic skeleton, such as phenol novolac-type epoxy resins, resorcinol-type epoxy resins, epoxy resins having a bisphenol skeleton, epoxy resins having a naphthalene skeleton, epoxy resins having a fluorene skeleton, epoxy resins having a biphenyl skeleton, epoxy resins having a bis(glycidyloxyphenyl)methane skeleton, epoxy resins having a xanthene skeleton, epoxy resins having an anthracene skeleton, and epoxy resins having a pyrene skeleton.

[0077] In addition, epoxy resins having an alicyclic skeleton, such as an epoxy resin having a dicyclopentadiene skeleton and an epoxy resin having an adamantane skeleton, can also be mentioned.

[0078] Other examples include aliphatic epoxy resins such as polyalkylene glycol diglycidyl ethers such as butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, trimethylolpropane polyglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, and polybutylene glycol diglycidyl ether.

[0079] Furthermore, hydrogenated products or modified products of the above-exemplified epoxy resins can also be used as the epoxy resin.

[0080] Examples of the epoxy resin having a bisphenol skeleton include epoxy resins having a bisphenol skeleton of bisphenol A type, bisphenol F type, or bisphenol S type.

[0081] Examples of the resorcinol-type epoxy resin include resorcinol diglycidyl ether.

[0082] Examples of the epoxy resin having a naphthalene skeleton include 1,2-diglycidylnaphthalene, 1,5-diglycidylnaphthalene, 1,6-diglycidylnaphthalene, 1,7-diglycidylnaphthalene, 2,7-diglycidylnaphthalene, triglycidylnaphthalene, and 1,2,5,6-tetraglycidylnaphthalene.

[0083] Examples of the epoxy resin having a fluorene skeleton include 9,9-bis(4-glycidyloxyphenyl)fluorene, 9,9-bis(4-glycidyloxy-3-methylphenyl)fluorene, 9,9-bis(4-glycidyloxy-3-chlorophenyl)fluorene, 9,9-bis(4-glycidyloxy-3-bromophenyl)fluorene, 9,9-bis(4-glycidyloxy-3-fluorophenyl)fluorene, 9,9-bis(4-glycidyloxy-3-methoxyphenyl)fluorene, 9,9-bis(4-glycidyloxy-3,5-dimethylphenyl)fluorene, 9,9-bis(4-glycidyloxy-3,5-dichlorophenyl)fluorene, and 9,9-bis(4-glycidyloxy-3,5-dibromophenyl)fluorene.

[0084] Examples of the epoxy resin having a biphenyl skeleton include 4,4′-diglycidylbiphenyl and 4,4′-diglycidyl-3,3′,5,5′-tetramethylbiphenyl. Examples of the epoxy resin having a bis(glycidyloxyphenyl)methane skeleton include 1,1'-bis(2,7-glycidyloxynaphthyl)methane, 1,8'-bis(2,7-glycidyloxynaphthyl)methane, 1,1'-bis(3,7-glycidyloxynaphthyl)methane, 1,8'-bis(3,7-glycidyloxynaphthyl)methane, 1,1'-bis(3,5-glycidyloxynaphthyl)methane, 1,8'-bis(3,7-glycidyloxynaphthyl)methane, 1,2'-bis(2,7-glycidyloxynaphthyl)methane, 1,2'-bis(3,7-glycidyloxynaphthyl)methane, and 1,2'-bis(3,5-glycidyloxynaphthyl)methane.

[0085] Examples of the epoxy resin having a xanthene skeleton include 1,3,4,5,6,8-hexamethyl-2,7-bis-glycidylmethoxy-9-phenyl-9H-xanthene, etc. Examples of the epoxy resin having an anthracene skeleton include epoxy resins having one or more anthracene skeletons and two or more epoxy groups or glycidyl groups in one molecule.

[0086] Examples of the epoxy resin having a pyrene skeleton include resins having one or more pyrene skeletons and two or more epoxy groups or glycidyl groups in one molecule.

[0087] Examples of the epoxy resin having a dicyclopentadiene skeleton include dicyclopentadiene dioxide and phenol novolac epoxy resins having a dicyclopentadiene skeleton. Examples of the epoxy resin having an adamantane skeleton include 1,3-bis(4-glycidyloxyphenyl)adamantane and 2,2-bis(4-glycidyloxyphenyl)adamantane.

[0088] As the bifunctional epoxy group-containing compound, among the above compounds, epoxy resins having an aromatic skeleton are preferred from the viewpoint of easily increasing the storage modulus, adhesive strength, and mechanical strength. Among them, epoxy resins having a bisphenol skeleton, i.e., bisphenol-type epoxy resins, are preferred. Furthermore, the combined use of an epoxy resin having an aromatic skeleton and an aliphatic epoxy resin is also preferred.

[0089] The bifunctional epoxy-containing compound may be used alone or in combination of two or more.

[0090] Examples of monofunctional epoxy-containing compounds include phenyl glycidyl ethers such as alkylphenyl glycidyl ethers represented by phenyl glycidyl ether, 4-tert-butylphenyl glycidyl ether, cresyl glycidyl ether, and nonylphenyl glycidyl ether, and monofunctional epoxy-containing compounds having an aromatic ring such as 1-glycidyl naphthalene and 2-glycidyl naphthalene. More preferred monofunctional epoxy-containing compounds having an aromatic ring are epoxy-containing compounds having a phenyl group. Using a monofunctional epoxy-containing compound having an aromatic ring can easily increase the storage modulus and thus improve the adhesive strength.

[0091] In addition, as monofunctional epoxy-containing compounds, aliphatic monofunctional epoxy-containing compounds are also preferred from the perspective of high raw material safety. Specific examples include glycidyl ethers of aliphatic alcohols. Here, the aliphatic alcohol may have a branched or linear structure, but a linear structure is preferred from the perspective of achieving good elongation. Furthermore, the aliphatic alcohol may have, for example, 4 to 24 carbon atoms, but preferably has 10 to 20 carbon atoms. Furthermore, from the perspective of achieving good elongation, the aliphatic alcohol is preferably a saturated aliphatic alcohol. Specific examples of glycidyl ethers of aliphatic alcohols include butyl glycidyl ether, decyl glycidyl ether, lauryl glycidyl ether, myristyl glycidyl ether, cetyl glycidyl ether, and stearyl glycidyl ether. The monofunctional epoxy group-containing compound may be a compound other than the above-mentioned compounds, and examples thereof include monofunctional epoxy group-containing compounds having a glycidyl group but not having an ether group, such as 1,2-butylene oxide and propylene oxide.

[0092] The monofunctional epoxy group-containing compound may be used alone or in combination of two or more.

[0093] For example, the epoxy-containing compound may have a molecular weight of 2000 or less, preferably 1000 or less, and more preferably 500 or less. By using an epoxy-containing compound having a molecular weight of a certain value or less, the viscosity of the adhesive can be reduced, and the thermally conductive filler can be highly filled. The molecular weight of the epoxy-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-containing compound to a certain value or more, the crosslinking density can be prevented from becoming higher than necessary, making it easier to achieve good elongation. In addition, the epoxy-containing compound may be liquid at room temperature (25°C).

[0094] The epoxy equivalent of the epoxy group-containing compound is preferably 1000 g / eq or less, more preferably 500 g / eq or less, further preferably 375 g / eq or less, and is preferably 100 g / eq or more, more preferably 125 g / eq or more, further preferably 140 g / eq or more.

[0095] The epoxy group-containing compound only needs to be liquid at room temperature (25°C). The viscosity of the epoxy resin at 25°C is not particularly limited; for example, it can be 50 Pa·s or less, and preferably 10 Pa·s or less. The viscosity of the epoxy resin at 25°C is not particularly limited; for example, it can be 0.5 mPa·s or more, or 1 mPa·s or more.

[0096] The viscosity of the epoxy resin and the amine compound described below is a viscosity measured using an E-type viscometer under the conditions of 10 rpm and 25°C.

[0097] Based on the total amount of curable composition, the content of epoxy-containing compound in the adhesive is, for example, 2% by mass or more and 20% by mass or less. When the content of epoxy-containing compound is 2% by mass or more, it is easy to improve bonding strength and elongation. In addition, if it is 20% by mass or less, it is not easy to have the composition of uncured epoxy-containing compound, which can prevent the adhesion from being hindered by the uncured component.

[0098] The content of the epoxy-containing compound is preferably 3% to 15% by mass, more preferably 4% to 12% by mass, and even more preferably 5% to 10% by mass, based on the total amount of the curable composition.

[0099] (Curing agent)

[0100] The adhesive may contain a curing agent to cure the main agent. Specifically, it preferably contains at least one of an amine and a thiol. When the adhesive contains an epoxy-containing compound, at least one of an amine and a thiol may be used. When the adhesive contains an amine or a thiol as a curing agent, it is easy to adjust the curing rate to a practical value at room temperature. Furthermore, the adhesive strength is easily improved.

[0101] The amine may be a polyamine such as a diamine or a triamine, or a monoamine, but is preferably a polyamine such as a diamine or a triamine.

[0102] Specific examples of the amine include polyoxyalkyleneamines such as polyoxyethylenediamine, poly(oxyethylene / oxypropylene)diamine, polyoxypropylenediamine, poly(oxybutylene / oxypropylene)diamine, polyethylene glycol bis(propylamine), trimethylolpropane poly(oxypropylene)triamine, glyceryl poly(oxypropylene)triamine, and methoxy poly(oxyethylene / oxypropylene)-2-propylamine; meta-phenylenediamine, para-phenylenediamine, meta-phenylenediamine, para-phenylenediamine, toluene-2,4-diamine, toluene-2,6-diamine, mesitylene-2,4-diamine, mesitylene-2,6-diamine, 3,5-diethyltoluene-2,4-diamine, 3,5-diethyltoluene-2,6-diamine, benzyldiamine, 4,4-diaminodiphenylmethane, Aromatic ring-containing amines such as 2,5-naphthalenediamine, 2,6-naphthalenediamine, and the 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, and 2,7-dimethyl-1,8-octanediamine; alicyclic amines such as 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, cyclohexanediamine, methylcyclohexanediamine, and isophoronediamine; and amide amines.

[0103] Examples of the amidoamine include compounds obtained by reacting aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, and azelaic acid, fatty acids, and carboxylic acid compounds such as dimer acid with aliphatic polyamines or polyamines having a polyoxyalkylene chain.

[0104] Alternatively, a Mannich base can be used as an amine. The Mannich base can be any Mannich base that can be used in an amine curing agent. For example, a Mannich base obtained by reacting a phenolic compound, an aldehyde compound, and an amine compound can be used. By using a Mannich base formed from a phenolic compound, the phenol structure contained in the Mannich base promotes the reaction between the main agent and the curing agent, speeding up the time to reach the gel point and easily exhibiting excellent rapid curing properties. Among Mannich bases, phenalkamine-type Mannich bases are preferably used.

[0105] Among the above, polyamines are more preferred from the perspective of ensuring rapid curing by ensuring a reaction rate with the main agent of at least a certain level. Among these, triamines are more preferred, and the combined use of diamines and triamines is even more preferred. Among diamines and triamines, the combined use of two or more amines with different reaction rates from the main agent allows the reaction between the main agent and the curing agent to proceed partially, thereby allowing the time to confirm the gel point to fall within a specified range, thereby ensuring rapid curing while extending the usable life. In this case, polyoxyalkyleneamines are more preferred over both diamines and triamines.

[0106] When using an amidoamine, it is preferred to use it in combination with a diamine or triamine other than the amidoamine. Furthermore, when using a Mannich base, it is preferred to use it in combination with a diamine or triamine other than the Mannich base as an amine curing agent, with its combination with a triamine being more preferred. In these cases, polyoxyalkyleneamines are preferred over both diamines and triamines. As described above, by using two amines as the amine curing agent, the time to confirm the gel point can be within a specified range, thereby extending the usable life while maintaining rapid curing properties.

[0107] The molecular weight of the amine used as the curing agent is preferably 3000 or less, more preferably 1000 or less, even more preferably 600 or less, and even more preferably 500 or less, from the viewpoint of improving rapid curing properties and reducing the viscosity of the adhesive before curing. The molecular weight of the amine curing agent is not particularly limited, but is, for example, 100 or greater, preferably 150 or greater, and more preferably 200 or greater.

[0108] The viscosity of the amine used as a curing agent at 25°C is preferably 15 Pa·s or less, more preferably 10 Pa·s or less, even more preferably 5 Pa·s or less, and even more preferably 3 Pa·s or less, from the perspective of improving rapid curing properties and reducing the viscosity of the adhesive before curing. The viscosity of the amine curing agent at 25°C is not particularly limited, but is, for example, 0.03 Pa·s or greater, preferably 0.05 Pa·s or greater, and more preferably 0.07 Pa·s or greater.

[0109] The amine content 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 amine content is 2% by mass or more, the main agent cures sufficiently, easily improving the modulus G'(60) and adhesive strength. Alternatively, when the amine content is 20% by mass or less, the main agent can be cured without excessive amine content.

[0110] The amine content is preferably 3% by mass to 15% by mass, more preferably 4% by mass to 12% by mass, and even more preferably 5% by mass to 10% by mass, based on the total amount of the curable composition.

[0111] Examples of thiols include polythiols such as dithiols and trithiols. Specific examples of thiols include esters of polyols such as pentaerythritol tetrakis(3-mercaptobutyrate), 1,4-bis(3-mercaptobutyryloxy)butane, and trimethylolpropane tris(3-mercaptobutyrate) with mercapto organic acids; aliphatic thiols such as alkyldithiols; and aromatic ring-containing thiols such as xylylenedithiol.

[0112] 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.

[0113] In the present invention, when an epoxy-based adhesive is used, it is preferred that a polyfunctional acrylate compound be included as a base agent in addition to an epoxy-containing compound. Specifically, the adhesive may be composed of an epoxy-containing compound as a base agent and a curing agent such as an amine, or it may be composed of an epoxy-containing compound as a base agent, a polyfunctional acrylate compound, and a curing agent such as an amine.

[0114] The polyfunctional acrylate compounds used in combination with the epoxy group-containing compound are shown below.

[0115] (Multifunctional acrylate compound)

[0116] A multifunctional acrylate compound is a compound having two or more functional groups (i.e., the number of (meth)acryloyl groups). Multifunctional acrylate compounds react rapidly with the aforementioned curing agents, particularly amines. Therefore, the use of a multifunctional acrylate compound facilitates early identification of the gel point, imparting rapid curing properties to the adhesive and providing a certain degree of adhesive strength in the initial curing stage.

[0117] As the polyfunctional acrylate compound, polyfunctional (meth)acrylate is preferably used, and esters of polyfunctional polyols and (meth)acrylic acid are more preferably used.

[0118] In this specification, “(meth)acryloyl” refers to either acryloyl or methacryloyl, and “(meth)acrylate” refers to either acrylate or methacrylate, and the same applies to other similar terms.

[0119] Examples of the bifunctional acrylate compound among the multifunctional acrylate compounds include 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 2-n-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, dimethyloltricyclodecane di(meth)acrylate, ethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, and dipropylene glycol di(meth)acrylate. (Meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, ethylene oxide-added bisphenol A di(meth)acrylate, propylene oxide-added bisphenol A di(meth)acrylate, ethylene oxide-added bisphenol F di(meth)acrylate, dimethylol dicyclopentadienyl di(meth)acrylate, ethylene oxide-modified isocyanuric acid di(meth)acrylate, 2-hydroxy-3-(meth)acryloyloxypropyl (meth)acrylate, carbonate diol di(meth)acrylate, polyether diol di(meth)acrylate, polyester diol di(meth)acrylate, polycaprolactone diol di(meth)acrylate, polybutadiene diol di(meth)acrylate, etc.

[0120] Examples of the trifunctional or higher functional acrylate compounds include trimethylolpropane tri(meth)acrylate, glycerol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ethylene oxide-added trimethylolpropane tri(meth)acrylate, propylene oxide-added trimethylolpropane tri(meth)acrylate, and caprolactone-modified trimethylolpropane tri(meth)acrylate. Ethylene oxide added isocyanurate tri(meth)acrylate, propylene oxide added glycerol tri(meth)acrylate, di(trimethylolpropane) tetra(meth)acrylate, alkylene oxide added pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tripentaerythritol octa(meth)acrylate, four-tetrapentaerythritol deca(meth)acrylate, tripentaerythritol hepta(meth)acrylate, four-tetrapentaerythritol nona(meth)acrylate, etc.

[0121] The number of functional groups in the multifunctional acrylate compound is preferably 3 or more, more preferably 4 or more, and even more preferably 5 or more. As the number of functional groups in the multifunctional acrylate compound increases, the gel point is confirmed earlier, the curing rate is improved, and the adhesive strength in the initial stage of curing is easily enhanced. The upper limit of the number of functional groups in the multifunctional acrylate compound is not particularly limited, and for example, it can be 10 or less, or 8 or less.

[0122] The molecular weight of the multifunctional acrylate compound is preferably below a certain value from the viewpoint of improving the rapid curing property and reducing the viscosity of the adhesive before curing. The specific molecular weight of the multifunctional acrylate compound can be, for example, 5000 or less, preferably 3000 or less, more preferably 1000 or less, and even more preferably 700 or less. In addition, regarding the molecular weight of the multifunctional acrylate compound, for example, a multifunctional acrylate compound of 150 or more, preferably 200 or more, more preferably 250 or more, and even more preferably 450 or more can be used. By setting the molecular weight of the multifunctional acrylate compound to above a certain value, the compressive load in the initial stage of curing is appropriately reduced, and the crosslinking density can be prevented from becoming higher than necessary, which facilitates improving the elongation and adhesion.

[0123] From the viewpoint of easily reducing the viscosity of the adhesive before curing, the polyfunctional acrylate compound is preferably liquid at room temperature (25° C.).

[0124] The functional group equivalent weight of the multifunctional acrylate compound is not particularly limited, but is preferably 500 g / eq or less, more preferably 300 g / eq or less, and even more preferably 150 g / eq or less. It is also preferably 75 g / eq or more, more preferably 80 g / eq or more, and even more preferably 85 g / eq or more.

[0125] In the adhesive, the ratio of the number of functional groups in the multifunctional acrylate compound to the number of functional groups in the epoxy resin can be approximately 0.1 to 1.5, preferably 0.2 to 1.2, more preferably 0.3 to 1.0, and even more preferably 0.4 to 0.85. If the ratio of the number of functional groups in the multifunctional acrylate compound is set within a specified range, the amine and the multifunctional acrylate compound preferentially cure in the initial stage, exhibiting rapid curing properties. Meanwhile, the reaction between the amine and the epoxy resin is suppressed, thereby maintaining a low compressive load in the initial stage of curing and extending the usable life.

[0126] Based on the total amount of the curable composition, the content of the multifunctional acrylate compound is, for example, 10% by mass or less, preferably 8% by mass or less. If the content of the multifunctional acrylate compound is set below the above-mentioned upper limit, it is possible to prevent the initial excessive curing by the multifunctional acrylate compound, thereby easily extending the usable time. In addition, if the content of the multifunctional acrylate compound is reduced, the moisture resistance is also improved. Therefore, even if it is used for a long time under high temperature and high humidity after curing, it is possible to maintain high bonding strength. The content of the multifunctional acrylate compound is more preferably 6% by mass or less, and further preferably 4% by mass or less.

[0127] In addition, the content of the multifunctional acrylate compound is preferably a certain amount or more in order to exhibit rapid curing properties and improve the adhesive strength in the initial stage of curing, based on the total amount of the curable composition, for example, 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.

[0128] The equivalent ratio in the curable composition is preferably 1.05 or more and 2.9 or less. The equivalent ratio in the curable composition is the equivalent ratio of the curing agent to the main agent constituting the adhesive, and specifically, is the ratio of the number of active hydrogen atoms in the curing agent to the number of functional groups in the components constituting the main agent contained in the curable composition.

[0129] Therefore, when the adhesive is composed of an epoxy-containing compound and an amine, the equivalent ratio is the equivalent weight of the active hydrogen atoms in the amino groups contained in the amine relative to the equivalent weight of the epoxy groups contained in the epoxy-containing compound. Alternatively, when the adhesive is composed of an epoxy-containing compound, a polyfunctional (meth)acrylate, and an amine, the equivalent ratio is the equivalent weight of the active hydrogen atoms in the amino groups relative to the sum of the equivalent weight of the epoxy groups contained in the epoxy-containing compound and the equivalent weight of the (meth)acryloyl groups contained in the polyfunctional acrylate compound.

[0130] Furthermore, when the binder is composed of an epoxy-containing compound and a thiol, the equivalent ratio is the ratio of the equivalent weight of active hydrogen in the thiol group contained in the thiol relative to the equivalent weight of the epoxy group contained in the epoxy-containing compound.

[0131] When the binder is composed of an epoxy-containing compound, an amine, and a thiol, the equivalent ratio is the ratio of the total equivalent of the active hydrogen of the thiol group contained in the thiol to the equivalent of the active hydrogen of the amino group contained in the amine relative to the equivalent of the epoxy group contained in the epoxy-containing compound.

[0132] By making the equivalent ratio of the above-mentioned functional groups be above 1.05, the number of amino active hydrogens becomes appropriate, and a certain reaction is also carried out in the initial stage of solidification, and fast curing is easily obtained. In addition, by being set to below 2.9, the number of amino active hydrogens is not too much, and the compressive load in the initial stage of solidification is reduced, which easily prolongs the usable time. In addition, by making the equivalent ratio within the scope of the above-mentioned regulations, it is easy to adjust the bonding strength to an appropriate range.

[0133] The equivalent ratio of the functional groups is more preferably 1.2 or more, further preferably 1.3 or more, further preferably 1.4 or more, and more preferably 2.6 or less, further preferably 2.1 or less, further preferably 1.8 or less.

[0134] The epoxy group equivalent can be obtained by dividing the content (g) of the epoxy resin in the curable composition by the epoxy equivalent (g / eq). However, when two or more epoxy resins are contained, the epoxy group equivalent can be obtained by adding the values ​​obtained by dividing the content (g) of each epoxy resin by the epoxy equivalent (g / eq).

[0135] The active hydrogen equivalent of the amino group can be obtained by dividing the amine content (g) in the curable composition by the active hydrogen equivalent of the amine (g / eq). However, when two or more amines are contained, the equivalent can be obtained by adding the values ​​obtained by dividing the content (g) of each amine by the active hydrogen equivalent (g / eq).

[0136] The (meth)acryloyl group equivalent can be obtained by dividing the content (g) of the acrylate compound in the curable composition by the (meth)acryloyl group equivalent (g / eq). However, when two or more acrylate compounds are contained, the value obtained by dividing the content (g) of each acrylate compound by the (meth)acryloyl group equivalent (g / eq) can be added together.

[0137] The epoxy equivalent weight (g / eq) can be calculated by dividing the molecular weight of an epoxy resin by the number of epoxy groups per molecule. The active hydrogen equivalent weight (g / eq) can be calculated by dividing the molecular weight of an amine by the number of active hydrogen atoms per molecule. Furthermore, the (meth)acryloyl equivalent weight (g / eq) can be calculated by dividing the molecular weight of an acrylate compound by the number of (meth)acryloyl groups per molecule.

[0138] The equivalent weight of active hydrogen in thiol groups is, for example, a value obtained by multiplying the amount of active hydrogen per unit amount of thiol in the adhesive (mol / g) by the thiol content. However, when two or more thiols are present, the equivalent weight is obtained by adding the values ​​obtained by multiplying the amount of active hydrogen per unit amount of each thiol (mol / g) by the content of each thiol.

[0139] When both amine and thiol are contained, the equivalent weight of active hydrogen of the amino group and thiol group is obtained by adding the equivalent weight of active hydrogen of the amino group and the equivalent weight of active hydrogen of the thiol group in the adhesive.

[0140] The molecular weight, epoxy group equivalent, active hydrogen equivalent and the number of (meth)acryloyl groups can be measured by mass spectrometry (GC-MS or LC-MS). In addition, when only the molecular weight can be determined by mass spectrometry, the number of epoxy groups (equivalent) and the number of active hydrogen groups (equivalent) per molecule can be determined by NMR ( 1H NMR, etc.). However, when the sample is a mixture, it is preferable to separate the components using GPC (gel permeation chromatography) or HPLC (high-performance liquid chromatography) before measuring NMR. Furthermore, if the structural formula of the epoxy resin is known, the molecular weight and number of epoxy groups can be calculated from the structural formula. Furthermore, if the structural formula of the amine is known, the molecular weight and number of active hydrogen atoms can be calculated from the structural formula. This also applies to acrylate compounds and thiols.

[0141] The number of active hydrogen atoms in an amine is 1 for NHR2 (secondary amino group) and 2 for NH2R (primary amino group) (wherein R in NHR2 and NH2R is a functional group other than active hydrogen atoms, i.e., a portion other than NH or NH2 of the amine).

[0142] In addition, regarding the number of active hydrogen atoms in a thiol, SHR is set to 1 (wherein R is a functional group other than active hydrogen atoms, that is, a portion other than SH of the thiol).

[0143] The content of the adhesive in the adhesive is preferably 8% by volume or more and 55% by volume or less relative to the volume of the entire adhesive. If it is above the above lower limit, the thermally conductive filler can be properly dispersed in the thermally conductive component and the adhesive. In addition, it is also possible to prevent the viscosity of the adhesive from becoming higher than necessary. In addition, by setting it below the above upper limit, it is easy to contain a certain amount of thermally conductive filler in the adhesive. The content of the adhesive in the adhesive is more preferably 15% by volume or more and 45% by volume or less, and further preferably 18% by volume or more and 38% by volume or less.

[0144] Thermally conductive filler

[0145] The adhesive of the present invention contains a thermally conductive filler. By including a thermally conductive filler in the adhesive, the thermal conductivity of the thermally conductive component formed from the adhesive is improved.

[0146] Examples of the thermally conductive filler include metals, metal oxides, metal nitrides, metal hydroxides, carbon materials, oxides other than metals, nitrides, and carbides. Examples of the shape of the thermally conductive filler include spherical and amorphous powders.

[0147] Examples of thermally conductive fillers include aluminum, copper, and nickel as metals, magnesium oxide, and zinc oxide as metal oxides, and aluminum nitrides such as aluminum nitride. Examples of metal hydroxides include aluminum hydroxide. Examples of carbon materials include spherical graphite. Examples of oxides, nitrides, and carbides other than metals include quartz, boron nitride, and silicon carbide. Among these, aluminum oxide is preferred from the perspective of improving the heat dissipation of the thermally conductive component, and aluminum hydroxide is preferred when improving flame retardancy. Furthermore, the combined use of aluminum oxide and aluminum hydroxide is also preferred.

[0148] As the thermally conductive filler, the above-mentioned materials may be used alone or in combination of two or more.

[0149] The average particle size of the thermally conductive filler is preferably 0.1 μm or more and 200 μm or less, more preferably 0.5 μm or more and 150 μm or less, and even more preferably 1 μm or more and 110 μm or less.

[0150] As the thermally conductive filler, it is preferable to use a combination of a small-particle thermally conductive filler with an average particle size of 0.1 μm to 5 μm and a large-particle thermally conductive filler with an average particle size of 5 μm to 200 μm. Using thermally conductive fillers with different average particle sizes can increase the filling rate.

[0151] The average particle size of the thermally conductive filler can be measured by observation using an electron microscope, etc. More specifically, for example, the particle sizes of 50 arbitrary thermally conductive fillers can be measured using an electron microscope or an optical microscope, and the average value (arithmetic mean) can be taken as the average particle size.

[0152] The content of the thermally conductive filler in the curable composition is preferably 40% by volume or more and 90% by volume or less relative to the volume of the entire adhesive. If it is above the above lower limit, it is possible to impart a certain thermal conductivity to the adhesive. In addition, by making the content of the thermally conductive filler below the above upper limit, the thermally conductive filler can be properly dispersed in the thermally conductive component, and the viscosity of the adhesive can be prevented from becoming higher than necessary. In addition, in the present invention, by lowering the viscosity of the adhesive, it is easy to increase the content of the thermally conductive filler. The content of the thermally conductive filler in the adhesive is more preferably 50% by volume or more and 85% by volume or less, and further preferably 60% by volume or more and 78% by volume or less.

[0153] The content of the thermally conductive filler in the curable composition, expressed in parts by mass, is preferably 150 parts by mass or more and 3000 parts by mass or less, more preferably 200 parts by mass or more and 2000 parts by mass or less, and even more preferably 300 parts by mass or more and 1000 parts by mass or less, per 100 parts by mass of the binder.

[0154] (Dispersant)

[0155] The curable composition of the present invention may contain a dispersant. Examples of the dispersant include polymeric dispersants. Examples of polymeric dispersants include polymer compounds having functional groups. Examples of polymer compounds include acrylic, vinyl, polyester, polyurethane, polyether, epoxy, polystyrene, amino, and siloxane compounds. Examples of functional groups include carboxyl, phosphoric, sulfonic, carboxylate, phosphate, sulfonate, hydroxy, amino, quaternary ammonium, and amide groups. Examples of dispersants include dispersants other than polymeric dispersants, such as alkoxysilane compounds.

[0156] The content of the dispersant in the adhesive is preferably 0.1 to 10 parts by mass, more preferably 0.2 to 5 parts by mass, and even more preferably 0.4 to 3 parts by mass, relative to 100 parts by mass of the binder.

[0157] (water)

[0158] The curable composition of the present invention may contain water. When the adhesive contains water, the water acts as a catalyst to facilitate the reaction between the main agent and the curing agent, particularly the acrylic compound and the amine.

[0159] 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. In addition, when the water content is 2.0% by mass or less, the following undesirable situations are unlikely to occur: the physical properties of the cured adhesive are reduced due to excessive water, or the curing is excessively advanced due to water, thereby shortening the usable life.

[0160] The water content is more preferably 0.3% by mass or more and 2.0% by mass or less, and still more preferably 0.5% by mass or more and 1.5% by mass or less.

[0161] Furthermore, when the adhesive contains water, the curing reaction easily proceeds even with a relatively small amount of the curing agent, and the gel point can be made to appear relatively quickly even with a relatively low equivalence ratio.

[0162] The water content in the curable composition can be determined by measuring it using the Karl Fischer method.

[0163] (Other additives)

[0164] The curable composition of the present invention may contain additives other than those mentioned above. Examples of such additives include curing catalysts such as bisphenol F that accelerate the reaction between the main component other than water and the curing agent, reaction rate control agents (reaction retardants) that inhibit the reaction between the main component and the curing agent, thixotropy-imparting agents such as amides, flame retardants, plasticizers, antioxidants such as phenolic antioxidants, and colorants.

[0165] When a plasticizer is used, it is preferred to use a plasticizer having a high molecular weight, and it is more preferred to use a reactive plasticizer or a substantially nonvolatile plasticizer.

[0166] Supply Form

[0167] The adhesive of the present invention may be supplied in a single-component form or a two-component form comprising a combination of a first component and a second component. From the viewpoint of storage stability, the two-component form is preferred.

[0168] In two-component adhesives, 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 preferably 0.9 to 1.1, and more preferably 0.95 to 1.05. By setting the volume ratio of the first component to the second component to 1 or a value close to 1, the adhesive can be easily prepared.

[0169] In two-component adhesives, it is preferable that both the first and second components be liquid at room temperature (25°C) and have the same compressive load, or, if different, a small difference. By ensuring that the compressive loads of the first and second components are equal or close to each other, uniform mixing of the adhesive is facilitated.

[0170] Specifically, the difference in compression load (N) between the first dose and the second dose is preferably 450 N or less, more preferably 250 N or less, and even more preferably 50 N or less. The compression load is measured as described in the Examples.

[0171] More specifically, a two-component adhesive can consist of a first component containing the adhesive's main component and a second component containing the adhesive's curing agent. The curing agent can be one that cures upon mixing with the first component. The following detailed description of the structure of a two-component adhesive will typically describe an epoxy-based adhesive.

[0172] In two-component adhesives, the first component preferably contains a base but no curing agent. Meanwhile, the second component contains a curing agent but may not contain a base. However, the second component may contain a base as long as it does not react with the curing agent.

[0173] The thermally conductive filler is contained in at least one of the first component and the second component, but is preferably contained in both the first component and the second component.

[0174] Therefore, it is preferred that the first component contain a base agent and a thermally conductive filler, and the second component contain a curing agent and a thermally conductive filler. Furthermore, it is more preferred that the first component contain no curing agent, and the second component contain no base agent. Therefore, it is even more preferred that the adhesive base agent be entirely contained in the first component, and the adhesive curing agent be entirely contained in the second component.

[0175] As mentioned above, the thermally conductive filler is preferably contained in both the first and second components, and more preferably, it is contained approximately equally in both. Specifically, the ratio (volume ratio) of the thermally conductive filler content in the second component to the thermally conductive filler content in the first component is preferably 0.67 to 1.5, more preferably 0.83 to 1.2, and even more preferably 0.91 to 1.1. By distributing the thermally conductive filler approximately equally between the first and second components, the difference in compressive load between the first and second components is easily reduced, and the volume ratio between the first and second components is also more likely to approach 1.

[0176] Furthermore, the difference in compressive load between the first and second doses can be adjusted by adjusting the viscosity of the epoxy-containing compound or curing agent, such as an amine. Specifically, to reduce the viscosity of the first dose of the epoxy-containing compound, a low-viscosity epoxy-containing compound can be used or its content can be increased. Furthermore, the viscosity can be lowered by adding a dispersant or plasticizer.

[0177] The densities of the first and second components are sometimes closer, making mixing easier. The difference in their densities is preferably smaller. Specifically, the ratio of the density of the first component to the density of the second component (also called the density ratio) is preferably 0.7 to 1.4, more preferably 0.8 to 1.2, and even more preferably 0.9 to 1.1. To reduce the density ratio, the content of the thermally conductive filler in the first and second components can be adjusted within the above range.

[0178] In a two-component type, a dispersant or other additives may be included in one or both of the first and second components, as needed. For example, if a dispersant or thermally conductive filler is included in both the first and second components, it suffices to include them in both. Water may be included in either the first or second component, but it is preferably included in the second component and not in the first component.

[0179] In two-component adhesives, the ratio of the functional group concentration (mol / g) of the second component to the functional group concentration (mol / g) of the first component is preferably 1.05 or higher and 2.9 or lower. By maintaining the functional group concentrations of the first and second components within this range, the base component and curing agent react at an appropriate equivalent ratio when the first and second components are mixed at a volume ratio of 1:1, facilitating rapid curing and extending the pot life.

[0180] The ratio of the functional group concentration is more preferably 1.2 or more, further preferably 1.3 or more, further preferably 1.4 or more, and is more preferably 2.6 or less, further preferably 2.1 or less, further preferably 1.8 or less.

[0181] The functional group concentration refers to the concentration of functional groups in the base or curing agent that are reactive with the curing agent or base. For epoxy-containing compounds, the epoxy groups serve as functional groups, and the number of epoxy groups per unit weight (g) serves as the functional group concentration. Furthermore, for amines and thiols, the active hydrogen serves as the functional group, and the number of active hydrogen per unit weight (g) serves as the functional group concentration.

[0182] For example, in a preferred embodiment, the first agent contains an epoxy-containing compound and a multifunctional acrylate compound but does not contain an amine or a thiol, and the second agent contains either an amine or a thiol but does not contain an epoxy-containing compound or a multifunctional acrylate compound. In this case, the total concentration of epoxy and (meth)acryloyl groups in the first agent becomes the functional group concentration of the first agent, and the concentration of active hydrogen of amines and thiols in the second agent becomes the functional group concentration of the second agent.

[0183] When the adhesive is a two-component type, the first and second components are preferably filled into separate containers. Specifically, the first component can be filled into a first container, and the second component can be filled into a second container. The first and second containers can be separate or integrated. By integrating the first and second containers, it is easier to supply them to the customer as a container kit. In this specification, the first container filled with the first component and the second container filled with the second component are sometimes collectively referred to as a container kit.

[0184] Examples of containers include, but are not limited to, syringes, liquid bags, buckets, and barrels. For example, when filling a syringe, a double-liquid parallel type syringe is preferred. Figure 1 As shown, in a two-liquid parallel syringe 30, a first syringe 31 constituting a first container and a second syringe 32 constituting a second container are arranged in parallel and integrated. The first dose 35 and the second dose 36 filled in the syringes 31 and 32 can be discharged from the syringes and mixed using the syringes as dispensers.

[0185] When using a liquid capsule, the container set consists of a first liquid capsule forming the first container and a second liquid capsule forming the second container. These liquid capsules may also be integrated. Furthermore, the liquid capsule is typically attached to a syringe (e.g., a first syringe and a second syringe). The first dose delivered from the first liquid capsule and the second dose delivered from the second liquid capsule can be dispensed and mixed from the respective discharge ports of the first and second syringes, using each syringe as a dispenser.

[0186] The mixing of the first agent and the second agent can be carried out in a mixer such as a static mixer. Figure 1 As shown, a static mixer 38 is connected to the discharge port 31A of the first syringe 31 and the discharge port 32A of the second syringe 32, and the first agent 35 and the second agent 36 discharged from the discharge ports 31A and 32A can be mixed within the mixer 38. The mixture (thermal conductive composition) obtained by mixing in the mixer 38 can be discharged from the discharge port 39 of the mixer 38.

[0187] Each syringe 31, 32 may have a structure in which the openings of the barrels 33A, 34A filled with the first dose 35 and the second dose 36, respectively, are closed with caps 33B, 34B. Figure 1 In the illustrated syringe 30 , the caps 33B and 34B can be removed, and the first and second doses 35 and 36 can be pushed out through the respective discharge ports 31A and 32A by pistons (not shown) inserted from the openings.

[0188] In addition, when using a bucket, Figure 2 As shown, the container kit may include a first pail 41 that constitutes a first container and is filled with a first agent 45, and a second pail 42 that constitutes a second container and is filled with a second agent 46. Furthermore, each pail 41, 42 is filled with, for example, the first agent 45 and the second agent 46, and includes a container body 43A, 44A having an opening, and a lid 43B, 44B that closes the opening of each container body 43A, 44A.

[0189] (Method for preparing adhesive)

[0190] When the adhesive of the present invention is a two-component adhesive, the first and second components can be obtained by mixing the components constituting the first and second components, respectively. Similarly, in the case of a single-component adhesive, the adhesive can be obtained by mixing the components constituting the adhesive. The method for mixing the components is not particularly limited, and the adhesive can be prepared by, for example, adding a thermally conductive filler and an additive such as a dispersant to the adhesive as needed, followed by stirring or kneading.

[0191] Alternatively, the thermally conductive filler can be surface-treated with a dispersant and then mixed with the adhesive. This pre-treatment of the thermally conductive filler with a dispersant modifies its surface. The pre-modified thermally conductive filler can then be mixed with the adhesive to prepare an adhesive.

[0192] The method for pre-treating the surface with a dispersant is not particularly limited and can be performed using known methods, such as wet treatment and dry treatment. In wet treatment, for example, a thermally conductive filler is added to a treatment solution containing a dispersant dispersed or dissolved in a solvent, mixed, and then dried, heated, or washed to cause the dispersant to bind or adhere to the surface of the thermally conductive filler. Dry treatment involves surface treatment without the use of a dispersion medium. Specifically, the dispersant is mixed with the thermally conductive filler, stirred using a mixer, and then heated to cause the dispersant to bind or adhere to the surface of the thermally conductive filler.

[0193] [Thermal conductive parts]

[0194] The adhesive of the present invention can be used as a thermally conductive component. The adhesive of the present invention becomes a thermally conductive component upon curing. The thermally conductive component of the present invention comprises a polymer matrix and a thermally conductive filler. The polymer matrix is ​​formed by curing the adhesive, and the thermally conductive filler is dispersed and retained within the polymer matrix. Thus, for example, if the adhesive is epoxy-based, the polymer matrix is ​​composed of a cured epoxy resin.

[0195] Thermally conductive components can be placed between two components, such as a heat generator and a heat sink. Heat generators include heat-generating electronic components like batteries. Heat sinks include cooling components like housings, radiators, and cooling plates.

[0196] The details of the thermally conductive filler in the thermally conductive filler are the same as those of the thermally conductive filler in the adhesive described above, and therefore, their description is omitted. Furthermore, the binder used to form the polymer matrix is ​​also the same as those in the adhesive described above, and therefore, their description is omitted. The same applies to the dispersant and other additives.

[0197] However, in the above description, the content of the adhesive and the content of the thermally conductive filler are described based on the volume of the entire adhesive. However, since the thermally conductive component is formed by the adhesive, the content based on the volume of the entire adhesive mentioned above can be regarded as the content based on the volume of the entire thermally conductive component in the thermally conductive component.

[0198] [use]

[0199] The adhesive and thermally conductive component of the present invention can be used in a variety of applications, including battery assemblies such as lithium-ion batteries (LiBs), power electronics, electronic packaging, LEDs, solar cells, power transmission networks, and other electronic equipment. They are preferably used in battery assemblies, and more preferably in LiB assemblies. Therefore, a preferred embodiment of the present invention provides a battery assembly having the aforementioned thermally conductive component. Furthermore, battery assemblies such as LiBs are particularly suitable for use in automobiles.

[0200] In battery assembly applications, the adhesive and thermally conductive component of the present invention are preferably used as spacers within battery assemblies. Furthermore, in one embodiment, the adhesive and thermally conductive component of the present invention are preferably used in battery modules, and more preferably as spacers within battery modules. The following describes an example of the thermally conductive component of the present invention being used in a battery module.

[0201] A battery module comprises a thermally conductive spacer, multiple battery cells, and a module housing that houses the cells. The spacer is located within the module housing. Spacers made of a thermally conductive material are placed between the battery cells and between the battery cells and the module housing, with the spacers being in close contact with the battery cells and the module housing. This spacer maintains the separation between the battery cells. Furthermore, the spacer between the battery cells and the module housing is in close contact with both, transferring heat generated by the battery cells to the module housing.

[0202] Figure 3 Indicates the specific structure of the battery module. Figure 4 Indicates the specific structure of each battery unit. Figure 3 As shown, a plurality of battery cells 11 are arranged inside the battery module 10. Each battery cell 11 is stacked and sealed in a flexible outer film, and the overall shape is a flat body with a thickness that is thinner than the height and width. Figure 4 As shown, the positive electrode 11a and the negative electrode 11b are exposed to the outside, and the center portion 11c of the flat surface is formed to be thicker than the end portion 11d to be crimped.

[0203] like Figure 3As shown, the battery cells 11 are arranged in such a manner that their offset planes are opposite to each other. Figure 3 In this structure, the gap members 13 are not filled to cover the entirety of the plurality of battery cells 11 housed within the module case 12. Instead, the gap members 13 are filled to fill the gaps existing within a portion (the bottom portion) of the interior of the module case 12. The gap members 13 are filled between the battery cells 11 and between the battery cells 11 and the module case 12, and are in close contact with the surfaces of the battery cells 11 and the inner surface of the module case 12 in these portions.

[0204] The spacers 13 inserted between the battery cells 11 adhere to the surfaces of both battery cells 11. However, due to the appropriate elasticity and flexibility of the spacers 13 themselves, even if external forces that might displace the spacing between the battery cells 11 are applied, the deformation caused by these forces can be mitigated. Therefore, the spacers 13 have the function of maintaining the separation between the battery cells 11.

[0205] The gap members 13 filling the gaps between the battery cells 11 and the inner surfaces of the module housing 12 are also tightly bonded to the surfaces of the battery cells 11 and the inner surfaces of the module housing 12. As a result, heat generated within the battery cells 11 is transferred via the gap members 13 bonded to the surfaces of the battery cells 11 to the inner surface of the module housing 12, which is in close contact with the other surface of the gap members 13.

[0206] The spacers 13 can be formed within the battery module 10 by applying a liquid adhesive using a conventional dispenser and then curing the liquid adhesive. Furthermore, the adhesive of the present invention, as previously described, has a low viscosity, thus facilitating the formation of the spacers 13 with good workability.

[0207] As mentioned above, a two-component adhesive is preferably used to form the gap member 13. A two-component adhesive is easy to store and, if mixed immediately before use, is less likely to solidify during application with a dispenser, rapidly solidifying after application. Application with a dispenser is also preferred because it allows for the liquid adhesive to be filled relatively deep within the battery module 10 casing 12.

[0208] The gap member 13 covering the battery cell 11 preferably covers 20 to 40% of each battery cell 11 on one side of the battery cell 11. By setting it to 20% or more, the battery cell 11 can be stably held. In addition, by fully covering the battery cell with a large amount of heat generated, the heat dissipation efficiency is improved. On the other hand, by setting it to 40% or less, the heat generated from the battery cell 11 can be effectively dissipated, and an increase in weight and deterioration in workability can also be prevented. In addition, in order to achieve good heat dissipation efficiency, it is preferred to cover the side of the battery cell 11 having the electrodes 11a and 11b with the gap member 13, and it is more preferred to cover the entire electrodes 11a and 11b with the gap member 13. As described above, the battery module 10 can dissipate the heat generated from the battery cell 11 to the module case 12 via the gap member 13.

[0209] The spacer 13 is also preferably used in battery packs that have multiple battery modules 10 inside. A battery pack generally includes multiple battery modules 10 and a battery pack housing that houses these modules 10. In such a battery pack, a spacer 13 can be provided between the battery modules 10 and the battery pack housing. This allows heat that has dissipated into the module housing 12 to be further dissipated into the battery pack housing, as described above, effectively dissipating the heat.

[0210] In addition, although the above description describes an example where the battery assembly is a battery module or a battery pack having a battery module, it can also be applied to a battery assembly that does not have a battery module, for example, it is also preferably applied to a battery assembly having a cell to pack (CTP) structure.

[0211] Figure 5 This is a schematic diagram of a battery assembly with a cell-to-pack structure. A battery assembly 20 with a cell-to-pack structure includes multiple battery cells 21 and a battery pack housing. The multiple battery cells 21 are bonded to a base member 25, which forms the battery pack housing, via a spacer 23 made of a thermally conductive material (a cured adhesive). The base member 25 may also constitute a chill plate, for example. Forming the spacer 23 in the battery assembly 20 can be performed similarly to forming the spacer 13 in the aforementioned battery module, for example, using a standard dispenser. The adhesive of the present invention has a low viscosity, making it easy to form the spacer 23. Furthermore, while the adhesive of the present invention cures quickly, it reduces the compressive load during the initial curing phase, extending its usable life. Therefore, even in battery assemblies with a cell-to-pack structure, the battery cells 21 can be bonded to the base member 25 with high workability.

[0212] Example

[0213] Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

[0214] [Thermal conductivity]

[0215] The thermal conductivity of the first and second adhesive agents was determined by measuring thermal resistance using a measuring device conforming to ASTM D5470-06.

[0216] Specifically, the adhesive is configured to be thicker than the thickness during measurement by covering the measuring die head on the heating element side, and then sandwiched with a radiator. The thickness of the adhesive is compressed to 1.0 mm, 1.5 mm, and 2.0 mm with a load of 30 psi, and the thermal resistance of each thickness is measured. The thickness can be adjusted with a gasket. For the values ​​of these three thermal resistances, a curve graph with the horizontal axis being the thickness and the vertical axis being the thermal resistance value is produced, and an approximate straight line at three points is obtained by the least squares method. The slope of the approximate straight line is then used as thermal conductivity.

[0217] The thermal resistance was measured at 80° C. using LW-9389 manufactured by Long Win Science and Technology Corporation. The area of ​​the measurement die was set to 1 inch×1 inch.

[0218] 〔Compression load〕

[0219] 2g of the formulated adhesive was placed on a piece of aluminum foil measuring 50mm x 50mm x 12μm thick. This was then wrapped in aluminum foil and placed in a 35°C thermostat for 6 minutes to prepare a measurement sample. Then, without placing a sample, the jig was pressed to the measurement location with a load of 3.6kg. The point 10mm from this location was designated as the measurement starting point (zero point). The compressive load of the measurement sample was measured under the following conditions. The same measurement was performed for the first and second doses.

[0220] Test speed: 60 mm / s

[0221] Jig size: 3cmφ

[0222] Result reading: The displacement of 8.80 mm is used as the compression load value.

[0223] Test environment: 25°C, 50% RH

[0224] The obtained compression load values ​​were evaluated in the following four grades: The compression load indicates the compression load at the initial stage of curing, and the lower the value, the easier the temporary bonding and the longer the usable time tend to be.

[0225] (Evaluation Criteria)

[0226] AA: 500N or less

[0227] A: Below 800N

[0228] B: greater than 800N and less than 1000N

[0229] C: greater than 1000N and less than 1500N

[0230] D: greater than 1500N

[0231] [Adhesion strength (after 1 hour)]

[0232] The adhesive strength of the cured adhesive at 18°C ​​(after 1 hour) was measured according to DIN EN 1465 using the following method. First, two PET plates (trade name "PET-6010," manufactured by Takiron C.I.) measuring 25 mm wide, 100 mm long, and 2 mm thick were prepared. Adhesive was then applied to the longitudinal end of one plate over a length of 5 mm across the entire width, resulting in a thickness of 1 mm after curing. The longitudinal end of the other plate was then superimposed on the applied adhesive and allowed to stand in an environment of 18°C ​​and 50% RH for 1 hour to cure the adhesive, thereby obtaining a test sample. The test sample consisted of two PET plates overlapped by a length of 5 mm across their entire width. The films were bonded to the overlapped portion via the cured adhesive (25 mm × 5 mm, 1 mm thick). The sample had dimensions of 25 mm wide and 195 mm long.

[0233] [Adhesion strength (after 18 hours)]

[0234] The adhesive strength (after 18 hours) was measured by the same method as the adhesive strength (after 1 hour) except that the adhesive was left to stand for 18 hours after application.

[0235] [Gelation time]

[0236] The modulus G' and modulus G'' of the sample obtained by mixing the first and second components were measured using a rheometer. Specifically, using an MCR-302e rheometer manufactured by Anton Paar, the changes in the modulus G' and G'' of each sample were measured continuously for 120 minutes at 25°C while generating deformation (strain) using a Peltier plate and a frequency of 1 Hz. The gelation time was then calculated as the time from the start of the measurement to the gelation point, where the modulus G' (storage modulus) and the modulus G'' (loss modulus) became equal. Measurements were initiated immediately after mixing the first and second components.

[0237] [Modulus G' (after 15 minutes)]

[0238] Using an Anton Paar rheometer MCR-302e, the Peltier plate was used to measure the deformation (strain) at 25°C at a frequency of 1 Hz, and the modulus G' was recorded 15 minutes after the start of the measurement. The measurement method and conditions were the same as those for the gelation time.

[0239] [Modulus G'' (after 15 minutes)]

[0240] Using an Anton Paar rheometer MCR-302e, measurements were performed at 25°C with a Peltier plate while generating deformation (strain) at a frequency of 1 Hz. The modulus G'' was recorded 15 minutes after the start of the measurement. The measurement method and conditions were the same as those for the gelation time described above.

[0241] [Storage modulus (after 60 minutes)]

[0242] Using an Anton Paar rheometer MCR-302e, deformation (strain) was generated at 25°C using a Peltier plate at a frequency of 1 Hz, and the modulus G' was recorded 60 minutes after the start of the measurement. The measurement method and conditions were the same as those for the gelation time.

[0243] [Examples 1 to 6, Comparative Examples 1 to 3]

[0244] The first and second agents were prepared by mixing the components according to the formulations in Tables 1 and 2. The prepared first and second agents were filled into 50cc two-liquid parallel-type capsules and mixed at a volume ratio of 1:1 using a static mixer at room temperature to produce an adhesive. The physical properties of the resulting adhesive were determined, and evaluation tests were also conducted.

[0245] The components used in each of the Examples and Comparative Examples are as follows.

[0246] (Epoxy-containing compounds)

[0247] Bisphenol F epoxy resin: Trade name "jER806", manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight 165 g / eq, molecular weight 330, viscosity (25°C) 2000 mPa·s (catalog value)

[0248] Multifunctional epoxy resin: Trade name "EX-321", manufactured by Nagase ChemteX, molecular weight 280, epoxy equivalent weight 140 g / eq, viscosity (25°C) 130 mPa·s (catalog value), trimethylolpropane polyglycidyl ether

[0249] Monofunctional epoxy resin: aliphatic glycidyl ether (aliphatic alcohol is C12-14), trade name "Epogosey ML", manufactured by Yokkaichi Synthetic Co., Ltd., epoxy equivalent weight is 282g / eq, number of functional groups is 1, molecular weight is 282

[0250] Glycidyl ether: Trade name "DENACOL EX146", manufactured by Nagase ChemteX, molecular weight 225, 4-tert-butylphenyl glycidyl ether, epoxy equivalent weight 225 g / eq

[0251] (Multifunctional acrylate compound)

[0252] Dipentaerythritol hexaacrylate: trade name "DPHA", manufactured by Daicel Ornex, molecular weight 520

[0253] (Amine curing agent)

[0254] Trimethylolpropane poly(oxypropylene) triamine: Trade name "T-403", manufactured by HUNTSMAN, molecular weight 440, viscosity (25°C) 0.7 Pa·s (catalog value), active hydrogen equivalent 73.3 g / eq

[0255] Poly(oxypropylene)diamine: Trade name "D-230", manufactured by HUNTSMAN, molecular weight 230, viscosity (25°C) 0.1 Pa·s (catalog value)

[0256] Poly(oxypropylene)diamine: Trade name "D-400", manufactured by HUNTSMAN, molecular weight 430, active hydrogen equivalent 107.5 g / eq, viscosity (25°C) 0.3 Pa·s (catalog value)

[0257] Polyamidoamine: Trade name "ancamide506", manufactured by EVONIK, active hydrogen equivalent is 110g / eq, viscosity (25℃) is 0.3Pa·s, amide amine

[0258] 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

[0259] Amidoamine: Trade name "TD-960", manufactured by DIC Corporation, active hydrogen equivalent: 77 g / eq, viscosity (25°C): 75 Pa·s (catalog value)

[0260] (Thixotropy-imparting agent)

[0261] Amide powder: Trade name "6650", manufactured by Kusumoto Chemicals Co., Ltd.

[0262] (Dispersant)

[0263] Polymer dispersants (copolymers containing acidic groups)

[0264] (Thermal conductive filling material)

[0265] Aluminum hydroxide 1: average particle size 1 μm

[0266] Aluminum hydroxide 2: average particle size 10 μm

[0267] Aluminum hydroxide 3: average particle size 50 μm

[0268] Aluminum hydroxide 4: average particle size 105μm

[0269] (catalyst)

[0270] Bisphenol F: Trade name "Bisphenol F", manufactured by Honshu Chemical Co.

[0271] pure water

[0272]

[0273]

[0274] As demonstrated in the above examples, curable thermally conductive adhesives meeting the requirements of the present invention exhibit an appropriate gelation time and demonstrate sufficient adhesion to provide temporary bonding one hour after mixing and applying the components. Furthermore, due to the low compression load and viscosity of the adhesive immediately after mixing, it can be applied to an adherend even in a fully compressed state. Furthermore, sufficient adhesion is demonstrated 18 hours after mixing and applying the components, resulting in an adhesive that cures quickly and offers a long usable life.

[0275] In contrast, in Comparative Example 1, since the gelation time was too short, the compressive load of the adhesive was high, the viscosity was high, and thus the usable time was shortened.

[0276] In addition, the adhesive prepared in Comparative Example 2 had an excessively long gelation time or an excessively low storage elastic modulus 60 minutes after mixing and applying the components, so that the adhesive did not sufficiently cure. Therefore, sufficient adhesive strength could not be exhibited even 18 hours after mixing and applying the components.

[0277] Furthermore, the adhesive prepared in Comparative Example 3 had an excessively low storage elastic modulus 60 minutes after mixing and applying the components. Therefore, the adhesive did not sufficiently cure, and therefore could not exhibit sufficient adhesive strength even 18 hours after mixing and applying the components.

[0278] Description of the accompanying drawings

[0279] 10 battery modules

[0280] 11, 21 battery cells

[0281] 12 Battery module housing (module housing)

[0282] 13, 23 gap parts

[0283] 20 battery pack

[0284] 25 basic components

[0285] 30 syringes

[0286] 31 First Syringe

[0287] 31A Discharge port of the first syringe

[0288] 32 Second syringe

[0289] 32A discharge port of the second syringe

[0290] 33A, 34A bobbins

[0291] 33B and 34B bobbin covers

[0292] 35, 45 first dose

[0293] 36, 46 Second dose

[0294] 38 Mixer

[0295] 39 Mixer outlet

[0296] 41 First Bucket

[0297] 42 The Second Bucket

[0298] 43A, 44A Container body with opening

[0299] 43B, 44B Cover for closing the opening of the container body

Claims

1. A curable thermally conductive adhesive comprising a curable binder and a thermally conductive filler, wherein when a rheometer is measured at a constant temperature of 25°C, a gel point at which the storage modulus and the loss modulus are equal is observed 5 minutes to 60 minutes after the start of the rheometer measurement, and the storage modulus at 25°C 60 minutes after the start of the rheometer measurement is 9.0×10 5 Pa or above.

2. The curable thermally conductive adhesive according to claim 1, wherein when measured by the rheometer, the loss modulus of the curable thermally conductive adhesive at 25° C. 15 minutes after the start of the rheometer measurement is 3.0×10 5 Below Pa. 3 . The curable thermally conductive adhesive according to claim 1 , wherein the binder contains an epoxy group-containing compound. The curable thermally conductive adhesive according to claim 1 or 2, wherein the binder contains at least one of an amine and a thiol. The curable thermally conductive adhesive according to claim 1 or 2, wherein the adhesive contains an epoxy group-containing compound and an amine. The curable thermally conductive adhesive according to claim 3 , wherein the epoxy-containing compound comprises a monofunctional epoxy-containing compound. 7 . The curable thermally conductive adhesive according to claim 1 , wherein the binder contains a Mannich base. 8 . The curable thermally conductive adhesive according to claim 1 , wherein the curable composition contains a multifunctional acrylate compound, an epoxy group-containing compound, and an amine. 9 . The curable thermally conductive adhesive according to claim 1 , wherein the equivalent ratio of active hydrogen in the curing agent to the equivalent ratio of functional groups of components constituting the main agent in the curable composition is 1.05 to 2.

9.

10. A supply form of a curable thermally conductive adhesive, which is the supply form of the curable thermally conductive adhesive according to claim 1 or 2. A first component containing a main component of the adhesive and a second component containing a curing agent that can be cured by mixing with the first component are filled in separate containers. 11 . The supply form of the curable thermally conductive adhesive according to claim 10 , wherein the difference between the viscosity of the first agent and the compressive load of the second agent is 450 N or less. 12 . The supply form of the curable thermally conductive adhesive according to claim 10 , wherein a ratio of a functional group concentration of the second agent to a functional group concentration of the first agent is 1.05 to 2.9.

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