Thermally conductive composition

Abstract

Disclosed is a two-part curable thermally conductive composition which is composed of: a first agent that contains at least a curable liquid resin and / or a plasticizer, and a thermally conductive filler, has a viscosity of 90 Pa∙s to 1000 Pa∙s inclusive, and is filled in a first container; and a second agent that contains at least the curable liquid resin and / or the plasticizer, has a viscosity of 10 Pa∙s or less, and is filled in a second container. The average particle diameter of the thermally conductive filler in the first agent is 5 μm or more, the second agent does not contain a thermally conductive filler, or in cases where the second agent contains a thermally conductive filler, the average particle diameter of the thermally conductive filler in the second agent is less than 5 μm, and the viscosity of the thermally conductive composition after mixing the first agent and the second agent with each other is not less than 1 Pa∙s but less than 60 Pa∙s.

Description

Thermally conductive composition

[0001] The present invention relates to a thermally conductive composition.

[0002] Thermally conductive compositions containing thermally conductive fillers are widely known as curable liquid compositions. For example, they are filled between a heat generating element and a heat sink, and then cured to form a cured product, which is used as a thermally conductive member such as a heat dissipating gap filler that transfers heat generated by the heat generating element to the heat sink.

[0003] In recent years, amid a market backdrop of steady growth in the production volume of electric vehicles (EVs), there has been an increasing demand for two-component, room-temperature curing heat-dissipating gap fillers for lithium-ion batteries (LiBs). From the viewpoint of heat dissipation, in lithium-ion batteries, thermally conductive compositions are often filled between components such as battery cells, battery modules, and battery packs in order to fix the components together and to improve heat dissipation.

[0004] For example, Patent Document 1 discloses an invention related to a thermally conductive curable composition comprising a first part and a second part. It is disclosed that the first part comprises a catalyst, a ceramic filler mixture, a low-volatility organic liquid, and water, while the second part comprises a silyl-modified reactive polymer, a low-volatility organic liquid, and a ceramic filler. Furthermore, paragraph 0038 discloses that the viscosity of the first part is greater than about 300 Pa·s, and the viscosity of the second part is about 200 to 1500 Pa·s.

[0005] Patent Document 2 discloses an invention relating to a thermally conductive silicone potting composition comprising a first component and a second component, wherein the first component comprises a vinyl organopolysiloxane, an alumina filler having an average particle size within a specific range, an aluminum hydroxide filler, and a catalyst, and the second component comprises a hydride organopolysiloxane, an alumina filler having an average particle size within a specific range, and an aluminum hydroxide filler.

[0006] Special table 2022-521790 publication Special table 2022-536577 publication

[0007] Depending on the assembly method of an electric vehicle, it may be desirable to inject a thermally conductive composition into the gap between the case and the battery cell or battery module after the battery cell or battery module has been housed in the case. Furthermore, in recent years, there has been a demand for smaller devices, and the gap has been narrowed. However, conventional thermally conductive compositions such as those described in Patent Document 1 have high viscosities, making it difficult to fully pour them into the gap when used in batteries. To address this issue, it has been considered to reduce the viscosity of the thermally conductive composition to the level described in Patent Document 2. However, this would result in the thermally conductive filler settling, and during storage of the thermally conductive composition, the thermally conductive filler would settle, forming a hard layer that is difficult to redisperse, resulting in the problem of a so-called hard cake.

[0008] Therefore, an object of the present invention is to provide a thermally conductive composition that has a low viscosity during use and can suppress settling of the thermally conductive filler during storage.

[0009] As a result of extensive research, the present inventors have found that the above-mentioned problems can be solved by adjusting the viscosity of a two-component curing thermally conductive composition so that it can be poured into narrow gaps when a first component containing a thermally conductive filler with a large average particle size and adjusted to have a high viscosity is mixed with a second component containing no thermally conductive filler with a large average particle size and adjusted to have a low viscosity. That is, the present invention provides the following [1] to

[17] .

[0010] [1] A two-component curing thermally conductive composition comprising: a first part containing at least one of a curable liquid resin and a plasticizer, and a thermally conductive filler, the first part having a viscosity of 90 Pa·s to 1000 Pa·s, and the first part being filled in a first container; and a second part containing at least one of the curable liquid resin and the plasticizer, the second part having a viscosity of 10 Pa·s or less, the second part being filled in a second container, wherein at least one of the first part and the second part contains the curable liquid resin, the thermally conductive filler in the first part having an average particle size of 5 μm or more, the second part being free of a thermally conductive filler or containing a thermally conductive filler with an average particle size of less than 5 μm, and the viscosity of the thermally conductive composition after mixing the first part and the second part is 1 Pa·s to 60 Pa·s. [2] The thermally conductive composition according to [1], wherein the curable liquid resin is an organic polymer having a hydrolyzable silyl group. [3] The thermally conductive composition according to [2], wherein the organic polymer having a hydrolyzable silyl group is a polyalkylene oxide having a hydrolyzable silyl group. [4] The thermally conductive composition according to [2] or [3], wherein at least one of the first and second parts contains a plasticizer. [5] The thermally conductive composition according to any one of [2] to [4], wherein either the first or second part contains water, and the other part contains a catalyst. [6] The thermally conductive composition according to any one of [2] to [5], wherein the first part contains either water or a catalyst, but not the other of water or a catalyst, and the second part does not contain an organic polymer having a hydrolyzable silyl group, but contains the other of water or a catalyst. [7] The thermally conductive composition according to any one of [2] to [6], wherein the first part does not contain water or a catalyst, and the second part does not contain an organic polymer having a hydrolyzable silyl group, but contains water and a catalyst. [8] The thermally conductive composition according to any one of [1] to [7], wherein the content of the thermally conductive filler is 10 to 80 volume %. [9] The thermally conductive composition according to any one of [1] to [8], wherein the thermally conductive filler comprises aluminum hydroxide.

[10] The thermally conductive composition according to any one of [1] to [9], wherein the thermally conductive filler comprises aluminum oxide.

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

[10] , wherein the thermal conductivity of a cured product of the thermally conductive composition is 1.0 W / m K or more.

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

[11] , wherein the difference in viscosity between the first part and the second part is 50 Pa s or more.

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

[12] , wherein the volume ratio of the first part to the second part when mixing the first part and the second part is 95 / 5 to 70 / 30.

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

[13] , wherein the specific gravity of the first part is greater than the specific gravity of the second part.

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

[14] , wherein the resin content of the second part is greater than the resin content of the first part.

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

[15] , wherein the second part contains a dispersant.

[17] A method for using a two-component curing thermally conductive composition comprising: a first part containing at least one of a curable liquid resin and a plasticizer, and a thermally conductive filler, and having a viscosity of 90 Pa·s or more and 1000 Pa·s or less, and filled in a first container; and a second part containing at least one of the curable liquid resin and the plasticizer, and having a viscosity of 10 Pa·s or less, and filled in a second container, wherein at least one of the first part and the second part is the curable liquid resin. wherein the thermally conductive filler in the first agent has an average particle size of 5 μm or more, the second agent does not contain a thermally conductive filler or contains the thermally conductive filler with an average particle size of less than 5 μm, the viscosity of the thermally conductive composition after mixing the first agent and the second agent is 1 Pa s or more and less than 60 Pa s, and the first agent and the second agent are mixed at a volume ratio of the first agent to the second agent (first agent / second agent) of 95 / 5 to 70 / 30, and then applied.

[0011] According to the present invention, it is possible to provide a thermally conductive composition that has a low viscosity during use and is capable of suppressing sedimentation of the thermally conductive filler during storage.

[0012] 1 is a schematic diagram showing a container set according to one embodiment. 2 is a schematic diagram showing a container set according to another embodiment. 3 is a graph showing the relationship between the mixing ratio of the first agent and the second agent and the viscosity after mixing the first agent and the second agent in Example 1.

[0013] [Thermal Conductive Composition] The thermally conductive composition of the present invention is a two-component curing thermally conductive composition comprising a first part and a second part. The first part contains at least one of a curable liquid resin and a plasticizer, and a thermally conductive filler, has a viscosity of 90 Pa·s or more and 1000 Pa·s or less, and is filled into a first container. The second part contains at least one of a curable liquid resin and a plasticizer, has a viscosity of 10 Pa·s or less, and does not contain a thermally conductive filler, or, even if it does contain a thermally conductive filler, the average particle size of the thermally conductive filler contained in the second part is less than 5 μm, and is filled into a second container. The viscosity of the thermally conductive composition obtained by mixing the first part and the second part (hereinafter also referred to as the "viscosity after mixing") is 1 Pa·s or more and less than 60 Pa·s.

[0014] Furthermore, in the thermally conductive composition of the present invention, the first part filled in the first container and the second part filled in the second container are stored in the containers without being mixed before use. By storing the first part and the second part separately in this manner, polymerization and hardening of the curable liquid resin during storage can be suppressed, thereby improving storage stability. The first part and the second part are mixed at the time of use and used as the thermally conductive composition.

[0015] <Viscosity> In the present invention, as described above, the viscosity of the first part is 90 Pa·s or more and 1000 Pa·s or less, the viscosity of the second part is 10 Pa·s or less, and the viscosity after mixing is 1 Pa·s or more and less than 60 Pa·s. If the viscosity of the first part is less than 90 Pa·s, the viscosity of the first part may be insufficient, which may cause sedimentation of the thermally conductive filler. On the other hand, if the viscosity of the first part exceeds 1000 Pa·s or the viscosity of the second part exceeds 10 Pa·s, the viscosity after mixing may not be sufficiently low. Furthermore, if the viscosity after mixing is less than 1 Pa·s, it may be difficult to incorporate a large amount of thermally conductive filler, which may result in problems such as poor handleability of the thermally conductive composition. Furthermore, if the viscosity after mixing exceeds 60 Pa·s, the coatability of the thermally conductive composition may be impaired, making it difficult to fill narrow gaps inside a battery module or the like with the thermally conductive composition.

[0016] From the above viewpoints, the viscosity of the first part is preferably 100 Pa·s or more and 700 Pa·s or less, more preferably 102 Pa·s or more and 500 Pa·s or less, and even more preferably 103 Pa·s or more and 300 Pa·s or less. The viscosity of the second part is preferably 8 Pa·s or less, more preferably 5 Pa·s or less, and even more preferably 3 Pa·s or less. On the other hand, from the viewpoint of adjusting the viscosity after mixing to a certain level or higher, the viscosity of the second part is preferably 0.01 Pa·s or more, more preferably 0.02 Pa·s or more, and even more preferably 0.03 Pa·s or more. The viscosity after mixing is preferably 1 Pa·s or more and 58 Pa·s or less, more preferably 2 Pa·s or more and 57 Pa·s or less, and even more preferably 3 Pa·s or more and 50 Pa·s or less. The above viscosities are all measured by a rheometer at 25° C. and a shear rate of 3.16 (1 / sec), and details are as described in the Examples.

[0017] In the thermally conductive composition of the present invention, the viscosity difference between the first and second parts is preferably 50 Pa·s or more, more preferably 60 Pa·s or more, and even more preferably 80 Pa·s or more. When the viscosity difference is equal to or greater than the above-mentioned lower limit, sedimentation of the thermally conductive filler is suppressed and the viscosity after mixing can be easily adjusted to a certain level or less. Furthermore, the viscosity difference is, for example, 500 Pa·s or less, preferably 300 Pa·s or less, and more preferably 200 Pa·s or less.

[0018] <Thermal Conductive Filler> The thermally conductive composition of the present invention contains a thermally conductive filler in at least the first agent, and the average particle size of the thermally conductive filler in the first agent is 5 μm or more. If the average particle size of the thermally conductive filler in the first agent is less than 5 μm, it becomes difficult to improve the thermal conductivity of the thermally conductive composition. The second agent may or may not contain a thermally conductive filler, but if it contains a thermally conductive filler, its average particle size is less than 5 μm. If the average particle size of the thermally conductive filler in the second agent is 5 μm or more, it becomes difficult to suppress sedimentation if the viscosity of the second agent remains low. From the above perspectives, the average particle size of the thermally conductive filler in the first agent is preferably 25 μm or more, and more preferably 40 μm or more, from the viewpoint of improving the thermal conductivity of the thermally conductive composition. On the other hand, the average particle size of the thermally conductive filler in the first agent is preferably 150 μm or less, more preferably 100 μm or less, and even more preferably 80 μm or less, from the viewpoint of maintaining a certain viscosity of the first agent or less. The average particle size of the thermally conductive filler in the second agent is preferably 3 μm or less, more preferably 1 μm or less. It is preferably 0.01 μm or more, more preferably 0.05 μm or more, and even more preferably 0.1 μm or more. The average particle size of the thermally conductive filler in the first and second agents is the average particle size of all the thermally conductive fillers contained in each agent. In this specification, the average particle size is the median diameter (D50) measured using a laser diffraction / scattering particle size distribution analyzer.

[0019] The content of the thermally conductive filler in the thermally conductive composition is preferably 10 to 80 vol%, more preferably 20 to 75 vol%, and even more preferably 35 to 72 vol%, based on the total amount of the thermally conductive composition. When the content of the thermally conductive filler is equal to or greater than the above-mentioned lower limit, the thermal conductivity of the thermally conductive composition is likely to be improved. Furthermore, when the content of the thermally conductive filler is equal to or less than the above-mentioned upper limit, the viscosity of the thermally conductive composition can be adjusted to a certain level or less, making it easier to fill narrow gaps inside a battery module or the like with the thermally conductive composition.

[0020] The content of the thermally conductive filler in the first agent is preferably 20% by volume or more, more preferably 30% by volume or more, and even more preferably 45% by volume or more, based on the total amount of the first agent. When the content of the thermally conductive filler in the first agent is equal to or greater than the above-mentioned lower limit, the viscosity of the first agent can be adjusted to a certain level or more, and settling of the thermally conductive filler can be easily suppressed. Furthermore, from the viewpoint of easily adjusting the viscosity of the first agent to a certain level or less, the content of the thermally conductive filler in the first agent is preferably 90% by volume or less, more preferably 85% by volume or less, and even more preferably 80% by volume or less, based on the total amount of the first agent.

[0021] The content of the thermally conductive filler in the second part is preferably 40% by volume or less, more preferably 30% by volume or less, and even more preferably 25% by volume or less, based on the total amount of the second part. By having the content of the thermally conductive filler in the second part be equal to or less than the above upper limit, the viscosity of the second part can be adjusted to a certain level or less, making it easier to fill narrow gaps inside a battery module or the like with the thermally conductive composition after mixing with the first part. The content of the thermally conductive filler in the second part may be 0% by volume or more, but from the perspective of thermal conductivity, a certain amount of the thermally conductive filler may be contained. In that case, the content of the thermally conductive filler is, for example, 1% by volume or more, preferably 5% by volume or more, and more preferably 10% by volume or more, based on the total amount of the second part.

[0022] Examples of thermally conductive fillers include metals, metal oxides, metal nitrides, metal hydroxides, carbon materials, non-metallic oxides, nitrides, and carbides. Furthermore, the thermally conductive filler may be spherical or in the form of an irregular powder. Examples of metals in the thermally conductive filler include aluminum, copper, and nickel. Examples of metal oxides include aluminum oxide (e.g., alumina), magnesium oxide, and zinc oxide. Examples of metal nitrides include aluminum nitride. Examples of metal hydroxides include aluminum hydroxide, magnesium hydroxide, and zinc hydroxide. Furthermore, examples of carbon materials include spherical graphite. Examples of non-metallic oxides, nitrides, and carbides include silicon oxides such as quartz, boron nitride, silicon carbide, and silica. Among these, metal oxides, metal nitrides, metal hydroxides, carbon materials, non-metallic oxides, nitrides, and carbides are preferred from the viewpoint of ensuring electrical insulation. Among these, it is preferable for the thermally conductive filler to include a thermally conductive filler having hydroxyl groups on its surface. When a thermally conductive filler having hydroxyl groups on its surface is used, for example, when the curable liquid resin contains an organic polymer having hydrolyzable silyl groups (described below), the organic polymer having hydrolyzable silyl groups and the thermally conductive filler are more likely to react. Therefore, even when the content of the curable liquid resin is low, the thermally conductive composition can be sufficiently cured and the thermal conductivity can be easily increased. Examples of thermally conductive fillers having hydroxyl groups on their surface include metal oxides and metal hydroxides. Among these, aluminum oxide is preferred as the metal oxide. Aluminum hydroxide is preferred as the metal hydroxide. It is preferable that the metal oxide and metal hydroxide are not surface-treated. This is because a surface-treated filler has fewer hydroxyl groups on its surface, making it less likely to react with the organic polymer. Therefore, untreated aluminum oxide is preferred as the metal oxide, and untreated aluminum hydroxide is preferred as the metal hydroxide. Note that the present invention does not preclude the use of surface-treated thermally conductive fillers. Surface treatment is performed, for example, by reacting a surface treatment agent such as a silane coupling agent with the surface of the thermally conductive filler.

[0023] The thermally conductive filler preferably contains a large-particle-size thermally conductive filler having an average particle size of 5 μm or more in the first agent. The inclusion of a large-particle-size thermally conductive filler having an average particle size of 5 μm or more facilitates increasing the thermal conductivity of the thermally conductive composition, as well as regulating the viscosity of the first agent to a certain level or higher, thereby making it easier to suppress sedimentation of the thermally conductive composition. The first agent may contain a small-particle-size thermally conductive filler having an average particle size of less than 5 μm in addition to the large-particle-size thermally conductive filler, as long as the overall average particle size of the thermally conductive filler is 5 μm or more. The second agent may also contain a small-particle-size thermally conductive filler having an average particle size of less than 5 μm, as described above. The average particle size of the large-particle-size thermally conductive filler is preferably 5 μm or more and 200 μm or less, more preferably 8 μm or more and 150 μm or less. The small-particle-size thermally conductive filler may have an average particle size of, for example, 10 nm or more and less than 5 μm, preferably 50 nm or more and 4 μm or less. The large-particle-size thermally conductive filler is preferably at least one selected from aluminum hydroxide and aluminum oxide. The small-particle-size thermally conductive filler is preferably at least one selected from aluminum hydroxide, aluminum oxide, and silica. When the second agent contains a small-particle-size thermally conductive filler, it is also preferable to use at least one selected from aluminum hydroxide and aluminum oxide in combination with silica as the small-particle-size thermally conductive filler. Powdered silica is preferred as the silica used as the small-particle-size thermally conductive filler. The inclusion of powdered silica helps to suppress sedimentation of the thermally conductive filler. Examples of powdered silica that can be used include fumed silica, colloidal silica, and silica gel. Of these, fumed silica is preferred. Examples of fumed silica that can be used include Aerosil (registered trademark) from Nippon Aerosil Co., Ltd.

[0024] <Curable Liquid Resin> The thermally conductive composition of the present invention contains a curable liquid resin. Before the first and second parts are mixed, the curable liquid resin may be contained in either the first part or the second part, or in both the first and second parts, but is preferably contained in the first part. By containing the curable liquid resin in the first part, the thermally conductive filler is held by the curable liquid resin, making it easier to suppress sedimentation of the thermally conductive filler during storage.

[0025] Examples of the curable liquid resin include urethane-based, silicone-based, epoxy-based, and organic polymers having a hydrolyzable silyl group, among which organic polymers having a hydrolyzable silyl group are preferred.

[0026] Here, examples of urethane-based resins include those composed of a polyol compound as a base component and a polyisocyanate compound as a curing agent. In this case, for example, the polyol compound as a base component may be included in the first component, and the polyisocyanate compound as a curing agent may be included in the second component. The silicone-based resin may be either a condensation-curable silicone resin or an addition-reaction-curable silicone resin, but addition-reaction-curable silicone resins are preferred. The addition-reaction-curable silicone resin may be composed of a silicone resin as a base component and a curing agent that hardens the base component. For example, in the case of an addition-reaction-curable silicone resin, an organopolysiloxane having an alkenyl group may be used as the base component, and an organohydrogenpolysiloxane may be used as the curing agent. Note that when an addition-reaction-curable silicone resin is used, for example, the silicone resin as a base component may be included in the first component, and the curing agent may be included in the second component. The epoxy-based resin may be composed of an epoxy group-containing compound as a base component and a curing agent. In this case, for example, the epoxy group-containing compound as the main component may be contained in the first component, and the curing agent may be contained in the second component. The epoxy group-containing compound may be a polyfunctional epoxy group-containing compound, a monofunctional epoxy group-containing compound, or a combination of these. For example, at least one of an amine and a thiol may be used as the curing agent for the epoxy-based resin, and it is preferable to use an amine. Furthermore, when an epoxy-based resin is used, in addition to the epoxy group-containing compound, a polyfunctional acrylate compound may also be contained as the main component. The polyfunctional acrylate compound may be contained in the first component, similar to the epoxy group-containing compound. Below, a detailed description will be given of the use of an organic polymer having a hydrolyzable silyl group as the curable liquid resin.

[0027] An organic polymer having a hydrolyzable silyl group can form a silanol group by hydrolysis with moisture such as humidity, followed by condensation polymerization of the silanol groups with each other or with the hydrolyzable silyl group to form a siloxane bond. This allows the organic polymer to form a crosslinked structure and harden, resulting in a rubber-like elastomer. The silanol group refers to a hydroxy group (Si—OH) directly bonded to a silicon atom. The hydrolyzable silyl group is preferably an alkoxysilyl group, and specific examples include a trimethoxysilyl group, a dimethoxysilyl group, a triethoxysilyl group, and a diethoxysilyl group. On the other hand, examples of the organic polymer include polyethers such as polyalkylene oxides.

[0028] A hydrolyzable silyl group is a group in which 1 to 3 hydrolyzable groups are bonded to a silicon atom. The hydrolyzable groups of the hydrolyzable silyl group are not particularly limited, and examples thereof include a hydrogen atom, a halogen atom, an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amide group, an acid amide group, an aminooxy group, a mercapto group, and an alkenyloxy group. Among these, an alkoxysilyl group is preferred as the hydrolyzable silyl group because of its mild hydrolysis reaction. Examples of the alkoxysilyl group include trialkoxysilyl groups such as trimethoxysilyl, triethoxysilyl, triisopropoxysilyl, and triphenoxysilyl groups; dialkoxysilyl groups such as dimethoxymethylsilyl and diethoxymethylsilyl groups; and monoalkoxysilyl groups such as methoxydimethylsilyl and ethoxydimethylsilyl groups. Of these, dialkoxysilyl groups are more preferred, and dimethoxymethylsilyl groups are particularly preferred.

[0029] The main chain of the organic polymer having a hydrolyzable silyl group may be linear or branched, but is preferably linear. That is, the organic polymer having a hydrolyzable silyl group of the present invention preferably has a hydrolyzable silyl group at the end of a linear main chain.

[0030] The terminal silylation rate of the organic polymer having a hydrolyzable silyl group is preferably 70% or more, more preferably 80% or more, and even more preferably 90% or more. When the terminal silylation rate is at a certain level or higher, it becomes possible to sufficiently cure the thermally conductive composition even when the content of the organic polymer having a hydrolyzable silyl group is low. The terminal silylation rate means the ratio of silylated terminals to all terminals of the organic polymer having a hydrolyzable silyl group. There is no particular upper limit to the terminal silylation rate, but it is, for example, 100% or less, and in practical use, can be 99% or less. The terminal silylation rate of the organic polymer having a hydrolyzable silyl group is １ It is determined by H-NMR.

[0031] The average number of hydrolyzable silyl groups in one molecule of the organic polymer having hydrolyzable silyl groups is preferably 1 to 3. When the number of hydrolyzable silyl groups in the polymer is within this range, the thermally conductive composition can be sufficiently cured even when the content of the organic polymer having hydrolyzable silyl groups is low. The average number of hydrolyzable silyl groups in one molecule of the organic polymer having hydrolyzable silyl groups can be measured by the following method: １ It can be calculated based on the concentration of hydrolyzable silyl groups in the organic polymer determined by H-NMR and the number average molecular weight of the polymer determined by GPC.

[0032] The method for introducing a hydrolyzable silyl group into an organic polymer is not particularly limited, and examples thereof include (1) a method in which an organic polymer modified with an unsaturated group in the molecule is subjected to hydrosilylation by the action of a hydrosilane having a hydrolyzable silyl group, (2) a method in which an organic polymer modified with an unsaturated group in the molecule is reacted with a compound having a mercapto group and a hydrolyzable silyl group, and (3) a method in which an organic polymer having a functional group in the molecule is reacted with a compound having a hydrolyzable silyl group and a functional group reactive with the functional group.Specific examples of the reaction that can be used include a reaction between an isocyanate group and a hydroxyl group, a reaction between an isocyanate group and an amino group, and a reaction between an isocyanate group and a mercapto group.

[0033] The organic polymer having a hydrolyzable silyl group is not particularly limited, and examples thereof include polyalkylene oxides such as polyethylene oxide, polypropylene oxide, polybutylene oxide, polytetramethylene oxide, polyethylene oxide-polypropylene oxide copolymers, and polypropylene oxide-polybutylene oxide copolymers; saturated hydrocarbon polymers; polychloroprene, polyisoprene, copolymers of isoprene or butadiene with acrylonitrile and / or styrene; polybutadiene, copolymers of isoprene or butadiene with acrylonitrile and styrene; (meth)acrylate polymers obtained by radical polymerization of monomers such as ethyl (meth)acrylate and butyl (meth)acrylate; Examples of such polymers include vinyl polymers obtained by radical polymerization of monomers such as vinyl acid, acrylonitrile, and styrene, graft polymers obtained by polymerizing vinyl monomers into the above polymers, polysulfide polymers, nylon 6 obtained by ring-opening polymerization of ε-caprolactam, nylon 6,6 obtained by condensation polymerization of hexamethylenediamine and adipic acid, nylon 6,10 obtained by condensation polymerization of hexamethylenediamine and sebacic acid, nylon 11 obtained by condensation polymerization of ε-aminoundecanoic acid, nylon 12 obtained by ring-opening polymerization of ε-aminolaurolactam, polyamide polymers such as copolymer nylons containing two or more of the above nylon components, polycarbonate polymers produced by condensation polymerization of bisphenol A and carbonyl chloride, and diallyl phthalate polymers. In this specification, (meth)acrylate means methacrylate or acrylate.

[0034] Among these, polyalkylene oxides are preferred as organic polymers from the viewpoint of achieving a desired viscosity range for the thermally conductive composition. That is, polyalkylene oxides having hydrolyzable silyl groups are preferred as organic polymers having hydrolyzable silyl groups. Among polyalkylene oxides, polypropylene oxide is particularly preferred.

[0035] The number-average molecular weight (Mn) of the organic polymer having a hydrolyzable silyl group is preferably 500 to 60,000, more preferably 500 to 30,000, even more preferably 1,000 to 20,000, even more preferably 1,500 to 20,000, even more preferably 2,000 to 15,000, and particularly preferably 2,500 to 10,000. When the number-average molecular weight of the organic polymer having a hydrolyzable silyl group is below these upper limits, the viscosity of the resulting thermally conductive composition is reduced, making it easier to fill narrow gaps inside battery modules and the like. Furthermore, when the number-average molecular weight of the organic polymer having a hydrolyzable silyl group is above these lower limits, sedimentation of the thermally conductive filler is more easily suppressed. Note that when the thermally conductive composition contains multiple organic polymers having hydrolyzable silyl groups, the number-average molecular weight (Mn) refers to the number-average molecular weight (Mn) of the entire composition.

[0036] In the present invention, the number average molecular weight of the organic polymer having a hydrolyzable silyl group refers to a value measured by GPC (gel permeation chromatography) in terms of polystyrene. In the measurement by GPC, for example, the measurement can be performed using an ACQUITY APC system manufactured by Waters Corporation, a Shodex KF604 GPC column manufactured by Tosoh Corporation, tetrahydrofuran as the solvent, a column temperature of 40° C., and a flow rate of 0.3 ml / min.

[0037] The polymer having a hydrolyzable silyl group can be a commercially available product. For example, examples of polyalkylene oxide polymers having a polypropylene oxide main chain skeleton and a dimethoxysilyl group at the end of the main chain skeleton include those manufactured by AGC Inc. under the product names "Excestar A2410," "Excestar S4530," and "Excestar S6250," and those manufactured by Kaneka Corporation under the product names "S203," "SAT115," and "SAX010."

[0038] In the thermally conductive composition of the present invention, the resin content of the second agent is preferably greater than the resin content of the first agent. Specifically, the resin content of the second agent is preferably at least 30% by volume greater, more preferably at least 40% by volume greater, and even more preferably at least 45% by volume greater, based on the total amount of each agent, than the resin content of the first agent. Having a resin content of the second agent greater than the resin content of the first agent allows the first agent to contain more thermally conductive filler than the second agent, making it easier to adjust the viscosity of the first and second agents to the desired range. In this case, the difference between the resin content of the first agent and the resin content of the second agent is, for example, 85% by volume or less, preferably 80% by volume or less, and more preferably 75% by volume or less, based on the total amount of each agent. In this specification, the resin content refers to the total volume fraction of the curable liquid resin, plasticizer, and the dehydrating agent, adhesion promoter, and dispersant (described later) in each agent.

[0039] The resin content in the first agent is preferably 5% by volume or more and 50% by volume or less, more preferably 10% by volume or more and 45% by volume or less, and even more preferably 20% by volume or more and 40% by volume or less, based on the total amount of the first agent. The resin content in the second agent is preferably 50% by volume or more and 99.7% by volume or less, more preferably 60% by volume or more and 99.5% by volume or less, and even more preferably 70% by volume or more and 99% by volume or less, based on the total amount of the second agent.

[0040] <Plasticizer> The thermally conductive composition of the present invention preferably contains a plasticizer. The plasticizer may be contained in at least one of the first and second parts, but is preferably contained in both the first and second parts. By containing a plasticizer, the viscosity of the thermally conductive composition can be adjusted to a certain level or lower, making it easier to fill narrow gaps inside a battery module or the like with the thermally conductive composition. Furthermore, it is preferable to contain a plasticizer, particularly when the curable liquid resin contains an organic polymer having a hydrolyzable silyl group. By containing a plasticizer together with the organic polymer having a hydrolyzable silyl group, it is easier to adjust the viscosity of the thermally conductive composition to a desired range.

[0041] Specific examples of plasticizers include organic ester plasticizers such as monobasic organic acid esters and polybasic organic acid esters, organic phosphate ester plasticizers such as organophosphorus plasticizers and organic phosphite ester plasticizers, and epoxy plasticizers such as sulfonamides and epoxidized soybean oil. Furthermore, the plasticizer is preferably an organic ester plasticizer. Examples of the monobasic organic acid ester include glycol esters obtained by reacting glycol with a monobasic organic acid. Examples of the glycol include triethylene glycol, tetraethylene glycol, and tripropylene glycol. Examples of the monobasic organic acid include butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, heptyl acid, n-octylic acid, 2-ethylhexyl acid, n-nonylic acid, decylic acid, and benzoic acid.

[0042] Examples of the polybasic organic acid ester include ester compounds of polybasic organic acids with alcohols having a linear or branched structure and 4 to 8 carbon atoms. Examples of the polybasic organic acids include adipic acid, sebacic acid, and azelaic acid. Examples of the organic ester plasticizer include triethylene glycol di-2-ethylpropanoate, triethylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylhexanoate, triethylene glycol dicaprylate, triethylene glycol di-n-octanoate, triethylene glycol di-n-heptanoate, tetraethylene glycol di-n-heptanoate, dibutyl sebacate, dioctyl azelate, dibutyl carbitol adipate, ethylene glycol di-2-ethylbutyrate, 1,3-propylene glycol di-2-ethylbutyrate, 1,4-butylene glycol di-2-ethylbutyrate, and diethylene glycol di-2-ethylbutylene. Examples of suitable organic ester plasticizers include ethylene glycol di-2-ethylhexanoate, dipropylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylpentanoate, tetraethylene glycol di-2-ethylbutyrate, diethylene glycol dicaprylate, diethylene glycol dibenzoate, dipropylene glycol dibenzoate, dihexyl adipate, dioctyl adipate, hexylcyclohexyl adipate, a mixture of heptyl adipate and nonyl adipate, diisononyl adipate, diisodecyl adipate, heptylnonyl adipate, dibutyl sebacate, oil-modified alkyd sebacate, and a mixture of a phosphate ester and an adipate. Organic ester plasticizers other than these may also be used. Adipic acid esters other than the above-mentioned adipic acid esters may also be used.

[0043] Examples of the organic phosphorus plasticizer include tributoxyethyl phosphate, isodecylphenyl phosphate, tris(2-ethylhexyl) phosphate, triisopropyl phosphate, etc. The plasticizer is preferably a diester plasticizer represented by the following formula (1): In the above formula (1), R1 and R2 each represent an organic group having 2 to 10 carbon atoms, R3 represents an ethylene group, an isopropylene group, or an n-propylene group, and p represents an integer of 3 to 10. In the above formula (1), R1 and R2 each preferably represent an organic group having 5 to 10 carbon atoms, and more preferably an organic group having 6 to 10 carbon atoms. The plasticizer preferably contains triethylene glycol di-2-ethylhexanoate (3GO), triethylene glycol di-2-ethylbutyrate (3GH), or triethylene glycol di-2-ethylpropanoate. The plasticizer more preferably contains triethylene glycol di-2-ethylhexanoate (3GO) or triethylene glycol di-2-ethylbutyrate (3GH), and even more preferably contains triethylene glycol di-2-ethylhexanoate.

[0044] From the viewpoint of reducing the viscosity of the first agent, the second agent, and the composition obtained by mixing these, the molecular weight of the plasticizer is preferably less than 1,000, more preferably less than 500, and preferably 50 or more, more preferably 100 or more. Furthermore, the molecular weight of the plasticizer is preferably 50 or more and less than 1,000, more preferably 100 or more and less than 500.

[0045] The content of the plasticizer in the thermally conductive composition is preferably 10 to 800 parts by mass, more preferably 50 to 700 parts by mass, and even more preferably 100 to 600 parts by mass, per 100 parts by mass of the organic polymer (curable liquid resin) having a hydrolyzable silyl group. When the amount of plasticizer is above these lower limits, the viscosity of the composition decreases, making it easier to suppress sedimentation of the thermally conductive filler. When the amount of plasticizer is below these upper limits, the amount of curable liquid resin can be kept above a certain level. Therefore, particularly when using a polymer having a hydrolyzable silyl group, a certain number of reaction sites with the thermally conductive filler can be ensured, making it easier to sufficiently cure the thermally conductive composition. Furthermore, the viscosity of the composition can be adjusted below a certain level, making it easier to fill narrow gaps inside battery modules, etc. The plasticizer may be included in at least one of the first and second parts, but it is preferable to include it in both the first and second parts. When a plasticizer is contained in both the first and second agents, the mass ratio of the plasticizer content in the first agent to the plasticizer content in the second agent may be, for example, 0.3 to 7, preferably 0.5 to 5, and more preferably 0.7 to 3. By setting the mass ratio of the plasticizer in each agent within the above range, it becomes easier to adjust the viscosity of each agent to a desired range.

[0046] <Catalyst> When at least one of the first and second parts constituting the thermally conductive composition of the present invention contains a polymer having a hydrolyzable silyl group as a curable liquid resin, it preferably contains a catalyst, and more preferably contains a silanol condensation catalyst. The inclusion of the catalyst, together with water described below, promotes the condensation reaction of the organic polymer having a hydrolyzable silyl group, thereby enabling the production of a high-quality cured product of the thermally conductive composition.

[0047] Examples of silanol condensation catalysts include organotin compounds such as dibutyltin dilaurate, dibutyltin oxide, dibutyltin diacetate, dibutyltin phthalate, bis(dibutyltin laurate)oxide, dibutyltin bis(acetylacetonate), dibutyltin bis(monoester maleate), tin octoate, dibutyltin octoate, dioctyltin oxide, dibutyltin bis(triethoxysilicate), bis(dibutyltin bistriethoxysilicate)oxide, dibutyltin oxybisethoxysilicate, and 1,1,3,3-tetrabutyl-1,3-dilauryloxycarbonyl-distannoxane, and organotitanium compounds such as tetra-n-butoxytitanate and tetraisopropoxytitanate. These silanol condensation catalysts may be used alone or in combination of two or more. Of the above, organotin compounds are preferred as the silanol condensation catalyst.

[0048] The content of the catalyst in the thermally conductive composition is preferably 0.3 to 15 parts by mass, more preferably 0.5 to 10 parts by mass, per 100 parts by mass of the organic polymer having a hydrolyzable silyl group. The content of the catalyst in at least one of the first and second parts is also preferably within this range. When the content of the silanol condensation catalyst is equal to or greater than these lower limits, the curing rate can be increased, and when the content of the silanol condensation catalyst is equal to or less than these upper limits, the curing rate can be appropriately controlled.

[0049] <Water> At least one of the first and second parts constituting the thermally conductive composition of the present invention preferably contains water. This is preferable because, after the first and second parts are mixed to prepare the thermally conductive composition, the composition can be quickly cured to its interior, which is preferable. The water content in the thermally conductive composition is preferably 0.1 to 25 parts by mass, more preferably 0.3 to 20 parts by mass, and even more preferably 0.5 to 15 parts by mass, per 100 parts by mass of the organic polymer having a hydrolyzable silyl group. The water content in at least one of the first and second parts is also preferably within the above range.

[0050] In the present invention, when the curable liquid resin contains a polymer having a hydrolyzable silyl group, it is preferable that either the first or second agent contains water, and the other agent contains a catalyst. Alternatively, the first agent may contain either water or a catalyst, but not the other, and the second agent may contain neither an organic polymer having a hydrolyzable silyl group, but the other of water or a catalyst. In this case, it is preferable that the first agent contains an organic polymer having a hydrolyzable silyl group. In the present invention, it is particularly preferable that only the first agent contains a polymer having a hydrolyzable silyl group and water, and only the second agent contains a catalyst. As described above, by separately containing a polymer having a hydrolyzable silyl group, water, and a catalyst, polymerization and curing of the organic polymer having a hydrolyzable silyl group during storage of the first and second agents can be suppressed, thereby improving storage stability. Furthermore, the first agent may contain neither water nor a catalyst, and the second agent may contain neither an organic polymer having a hydrolyzable silyl group, but water and a catalyst.

[0051] <Dispersant> In the thermally conductive composition of the present invention, the second agent does not need to contain a dispersant, but it is preferable that the second agent contain a dispersant. By including a dispersant, after mixing the first agent and the second agent, the dispersant acts on the thermally conductive filler contained in the first agent, allowing the thermally conductive filler to be properly dispersed throughout the composition. This allows the viscosity of the thermally conductive composition to be adjusted to a certain level or lower, making it easier to fill narrow gaps inside battery modules and the like. Furthermore, the first agent may or may not contain a dispersant. By not including a dispersant in the first agent, the viscosity of the first agent can be adjusted to a certain level or higher, making it easier to suppress sedimentation of the thermally conductive filler. Furthermore, by including a dispersant in the first agent, the viscosity reduction effect after mixing the first agent and the second agent can be enhanced.

[0052] Examples of dispersants include polymeric dispersants. Examples of polymeric dispersants include polymeric compounds having functional groups. Examples of polymeric compounds include acrylic, vinyl, polyester, polyurethane, polyether, epoxy, polystyrene, amino, and silicone compounds. Examples of functional groups include carboxyl groups, phosphoric acid groups, sulfonic acid groups, carboxylic acid ester groups, phosphoric acid ester groups, sulfonic acid ester groups, hydroxyl groups, amino groups, quaternary ammonium bases, and amide groups. Dispersants other than polymeric dispersants may also be used, such as alkoxysilane compounds.

[0053] The content of the dispersant in the thermally conductive composition is preferably 0.1 to 40 parts by mass, and more preferably 0.5 to 30 parts by mass, per 100 parts by mass of the organic polymer (curable liquid resin) having a hydrolyzable silyl group. When the dispersant is contained only in the second agent, the content of the dispersant is also preferably within the above range.

[0054] <Adhesion Promoter> The thermally conductive composition of the present invention preferably contains an adhesion promoter. The adhesion promoter may be contained in at least one of the first and second parts, but from the viewpoint of storage stability, it is preferable that the adhesion promoter is not contained in the first part but is contained in the second part. The adhesion promoter can further improve the adhesiveness of the thermally conductive composition when it is cured.

[0055] As the adhesion promoter, an aminosilane coupling agent is preferred. Specific examples of the aminosilane coupling agent include 3-aminopropyltrimethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, N,N'-bis-[3-(trimethoxysilyl)propyl]ethylenediamine, N,N'-bis-[3-(triethoxysilyl)propyl]ethylenediamine, N,N'-bis-[3-(methyldimethoxysilyl)propyl]ethylenediamine, N,N'-bis-[3-(trimethoxysilyl)propyl]hexamethylenediamine, and N,N'-bis-[3-(triethoxysilyl)propyl]hexamethylenediamine. Of these, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane is preferred.

[0056] The content of the adhesion promoter in the thermally conductive composition is preferably 1 to 20 parts by mass, more preferably 1 to 15 parts by mass, per 100 parts by mass of the organic polymer containing a hydrolyzable silyl group. The content of the adhesion promoter in the second part is also preferably within this range. When the content of the adhesion promoter is equal to or greater than these lower limits, the adhesive strength of the cured product formed is likely to be improved. When the content of the adhesion promoter is equal to or less than these upper limits, the cured product formed can be prevented from becoming brittle, thereby suppressing a decrease in adhesive strength.

[0057] <Dehydrating Agent> The thermally conductive composition preferably contains a dehydrating agent. The dehydrating agent may be contained in either the first or second agent, whichever does not contain water, but is preferably contained only in the second agent. By including a dehydrating agent, curing of the first or second agent due to moisture contained in the air or the like during storage can be suppressed. Examples of dehydrating agents include silane compounds such as vinyltrimethoxysilane, dimethyldimethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, tetramethoxysilane, phenyltrimethoxysilane, and diphenyldimethoxysilane; ester compounds such as methyl orthoformate, ethyl orthoformate, methyl orthoacetate, and ethyl orthoacetate; and inorganic dehydrating agents such as zeolite. These dehydrating agents may be used alone or in combination of two or more. Among these, vinyltrimethoxysilane is preferred.

[0058] The content of the dehydrating agent in the first or second part is preferably 0.5 to 20 parts by mass, more preferably 1 to 15 parts by mass, per 100 parts by mass of the organic polymer having a hydrolyzable silyl group contained in the thermally conductive composition obtained by mixing the first and second parts. When the content of the dehydrating agent is equal to or greater than these lower limits, curing during storage is easily suppressed, while when the content of the dehydrating agent is equal to or less than these upper limits, an increase in hardness over time due to the dehydrating agent is less likely to occur. Similarly, the content of the dehydrating agent in the thermally conductive composition is preferably 0.5 to 20 parts by mass, more preferably 1 to 15 parts by mass, per 100 parts by mass of the organic polymer having a hydrolyzable silyl group.

[0059] <Other Components> In the present invention, the first agent, the second agent, and the thermally conductive composition obtained by mixing these may contain other additives such as an antioxidant, an ultraviolet absorber, an antifoaming agent, a pigment, a dye, an anti-settling agent, and a solvent.

[0060] <Volume Ratio and Specific Gravity of First Agent and Second Agent> When mixing the first agent and the second agent, the volume ratio of the first agent to the second agent (first agent / second agent) is preferably 95 / 5 to 70 / 30, more preferably 95 / 5 to 75 / 25, and even more preferably 94 / 6 to 80 / 20. By mixing the first agent at a higher ratio than the second agent in this way, it becomes easier to maintain high thermal conductivity after mixing.

[0061] Furthermore, the specific gravity of the first agent is preferably greater than that of the second agent. Specifically, the specific gravity of the first agent is preferably greater than that of the second agent by 0.2 or more, more preferably by 0.3 or more, and even more preferably by 0.5 or more. Having the specific gravity of the first agent greater than that of the second agent makes it easier to adjust the viscosity of the first and second agents to a desired range. In this case, the difference between the specific gravity of the first agent and the specific gravity of the second agent is, for example, 1.5 or less, preferably 1.2 or less, and more preferably 1.1 or less.

[0062] The specific gravity of the first agent is preferably 1.6 to 3, more preferably 1.75 to 2.5, and even more preferably 1.9 to 2.2. The specific gravity of the second agent is preferably 0.3 to 1.8, more preferably 0.5 to 1.5, and even more preferably 0.8 to 1.3.

[0063] <Supply Form> The first container filled with the first agent and the second container filled with the second agent may be separate or integrated. The integration of the first container and the second container facilitates supply to the consumer as a container set. In this specification, the first container filled with the first agent and the second container filled with the second agent may be collectively referred to as a container set.

[0064] Examples of the container include, but are not limited to, a syringe and a cartridge. For example, when filling a syringe, it is preferable to use a two-liquid parallel type syringe. As shown in FIG. 1 , a two-liquid parallel type syringe 30 is an integrated syringe in which a first syringe 31 constituting a first container and a second syringe 32 constituting a second container are arranged in parallel. The first agent 35 and the second agent 36 filled in the syringes 31 and 32 are preferably discharged from the syringes as dispensers and mixed.

[0065] When cartridges are used, the container set comprises a first cartridge constituting the first container and a second cartridge constituting the second container, and these cartridges may be integrated. The cartridges are usually set in syringes (e.g., a first syringe and a second syringe), and the first agent delivered from the first cartridge and the second agent delivered from the second cartridge are preferably discharged from the respective outlets of the first syringe and the second syringe, using each syringe as a dispenser, and then mixed.

[0066] The first and second agents may be mixed using a mixer such as a static mixer. As shown in FIG. 1 , the static mixer 38 is connected to the outlet 31A of the first syringe 31 and the outlet 32A of the second syringe 32, and the first agent 35 and the second agent 36 discharged from the outlets 31A and 32A can be mixed inside the mixer. The mixture (thermally conductive composition) obtained by mixing in the mixer 38 may be discharged from the outlet 39 of the mixer 38. Each syringe 31, 32 may have a structure in which the openings of barrels 33A, 34A, into which the first agent 35 and the second agent 36, respectively, are filled, are closed by lids 33B, 34B. In the syringe 30 shown in FIG. 1, the first agent 35 and the second agent 36 are preferably ejected from the respective outlets 31A and 32A after the respective lids 33B and 34B are removed and the first agent 35 and the second agent 36 are pushed out by pistons (not shown) inserted through the openings.

[0067] 2, the container set may include a first pail 41 that constitutes the first container and is filled with a first agent 45, and a second pail 42 that constitutes the second container and is filled with a second agent 46. Each pail 41, 42 may include, for example, a container body 43A, 44A that is filled with the first agent 45 and the second agent 46 and has an opening, and a lid 43B, 44B that closes the opening of each container body 43A, 44B.

[0068] <Thermal Conductivity> The thermal conductive composition of the present invention preferably has a thermal conductivity of 1.0 W / m·K or more, more preferably 1.2 W / m·K or more, and even more preferably 1.4 W / m·K or more, of the cured product. A thermal conductivity of at least the above lower limit can be said to be excellent in thermal conductivity. The higher the thermal conductivity, the better, but in practical terms, it is, for example, 50 W / m·K or less, preferably 40 W / m·K or less. The thermal conductivity may be measured, for example, on a cured product obtained by mixing the first and second parts to obtain a thermal conductive composition, and then leaving the thermal conductive composition to cure in an environment of 25°C and 50% RH for two weeks.

[0069] [Applications] The thermally conductive composition of the present invention can be used in a variety of applications. The composition can suppress sedimentation of the thermally conductive filler during storage of the first and second parts, while maintaining a viscosity of at most a certain level after mixing the first and second parts. This makes the composition particularly suitable for use as a gap filler for filling narrow gaps. Specific applications include, for example, gap fillers in batteries, electronic devices, semiconductor devices, and the like, and the composition is preferably used in battery applications. When used in battery applications, gap fillers made of the thermally conductive composition are filled between battery cells, between a battery cell and a battery module case, between a battery cell and a battery pack case, between a battery cell and a cooling plate, between a battery module case and a cooling plate, or between a battery pack case and a cooling plate. The gap filler thus filled may be in close contact with the battery cell, battery module case, battery pack case, or cooling plate. This allows the gap filler between battery cells to maintain a separation between the battery cells. Furthermore, the gap material between the battery cell and the battery module case, between the battery cell and the battery pack case, or between the battery cell and the cooling plate is in close contact with both the battery cell and the battery module case, the battery pack case, or the cooling plate, and has the function of conducting heat generated in the battery cell to the battery module case, the battery pack case, or the cooling plate. When the thermally conductive composition is used for a battery, there are no particular limitations, but it is preferably used in a two-wheeled vehicle, a three-wheeled vehicle, or an automobile, and more preferably used in a two-wheeled vehicle, a three-wheeled vehicle, or an automobile equipped with a lithium-ion battery.

[0070] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples in any way.

[0071] In this example, the evaluation was carried out by the following method.

[0072] [Viscosity] The viscosity (Pa·s) at 25°C of each of the first and second parts, and the thermally conductive composition obtained by mixing them, was measured using the following method. Using a rheometer (e.g., an Anton Paar MCR-302e rheometer), the sample temperature was adjusted to 25°C using a Peltier plate, and viscosity measurements were performed using φ20 mm parallel plates with a gap of 1 mm, while continuously changing the shear rate within a range of 0.0001 to 100 (1 / sec). The viscosity value was measured at a shear rate of 3.16 (1 / sec). The viscosity difference was calculated based on the measured values ​​of the viscosity of the first and second parts. The viscosity of the thermally conductive composition was measured immediately after mixing the first and second parts. Here, "immediately after mixing" means measuring before a significant increase in viscosity occurs. The above samples (i.e., the first and second parts) were stirred for 1 minute to obtain a thermally conductive composition, and the viscosity of the thermally conductive composition was measured within 10 minutes after the stirring was completed.

[0073] [Settling Suppression] After preparing the first and second agents, the settling suppression of each of the first and second agents was evaluated after 168 hours at 35°C. The evaluation criteria are as follows: A: No separation into two layers occurred after 168 hours at 35°C. B: Separation into two layers occurred after 168 hours at 35°C, but redispersibility was possible by shaking by hand. C: Separation into two layers occurred after 168 hours at 35°C, and redispersibility was not possible by shaking by hand. The combined evaluation results for the first and second agents are also shown in Tables 1 and 2. The combined evaluation results indicate the worse results for settling suppression among the evaluation results for the first and second agents.

[0074] [Coating property] Coating property was evaluated using a viscosity cup (Model No. 321 / No. 5 manufactured by DKSHG) with an opening diameter of 8 mm conforming to DIN 53211 standard, by placing 50 g of the thermally conductive composition prepared by the method described in the Examples into the cup and measuring the amount dispensed per minute. The evaluation criteria are as follows: A: Dispensation amount was 25 g or more. B: Dispensation amount was 0.5 g or more but less than 25 g. C: Dispensation amount was less than 0.5 g.

[0075] [Thermal Conductivity] The thermal conductive compositions prepared in each Example and Comparative Example were cured for two weeks at 25°C and 50% RH to obtain cured samples, and the thermal conductivity was measured. Thermal conductivity was determined by measuring thermal resistance using a measuring device conforming to ASTM D5470-06. Specifically, cured samples with thicknesses of 1.0 mm, 1.5 mm, and 2.0 mm were prepared, and the thermal resistance and thickness were measured when compressed at a pressure of 30 psi. A graph was created for these three thermal resistance values, with the horizontal axis representing thickness and the vertical axis representing thermal resistance, and an approximate line between three points was determined using the least squares method. The slope of the approximate line represents the thermal conductivity. Thermal resistance measurements were performed at 80°C using an "LW-9389" thermometer manufactured by Long Win Science and Technology Corporation. The thermal conductivity of the thermal conductive compositions was evaluated based on the thermal conductivity measured using the above method. The evaluation criteria are as follows: A: 1.0 W / m·K or more B: 0.8 W / m·K or more but less than 1.0 W / m·K C: Less than 0.8

[0076] [Overall Evaluation] The lowest evaluation result among the results of settling prevention, application property, and thermal conductivity was adopted as the overall evaluation.

[0077] The components used in the examples are as follows.

[0078] <Organic polymers having hydrolyzable silyl groups> Kaneka Corporation's "MS polymer SAT115", number average molecular weight 3,400, linear type, terminal silylation rate 60%, organic polymer having dimethoxymethylsilyl groups at both ends of polypropylene oxide Kaneka Corporation's "MS polymer SAX010", number average molecular weight 2,400, linear type, terminal silylation rate 94%, organic polymer having dimethoxymethylsilyl groups at both ends of polypropylene oxide AGC Corporation's "Excestar S6250", branched type, organic polymer having dimethoxymethylsilyl groups at each end of branched polypropylene oxide Kaneka Corporation's "MS polymer SAX015", number average molecular weight 5,000, branched type, terminal silylation rate 95%, organic polymer having dimethoxymethylsilyl groups at both ends of branched polypropylene oxide

[0079] <Thermal conductive filler> Aluminum hydroxide 1 (average particle size 1 μm) Aluminum hydroxide 2 (average particle size 10 μm) Aluminum hydroxide 3 (average particle size 50 μm) Aluminum hydroxide 4 (average particle size 100 μm)

[0080] <Plasticizer> Triethylene glycol di(2-ethylhexanoate) 3GO

[0081] <Additives> Dehydrating agent: vinyltrimethoxysilane Adhesion promoter: N-(2-aminoethyl)-3-aminopropyltrimethoxysilane Silanol condensation catalyst: organotin curing catalyst ("KSF-01" manufactured by Sankyo Pharmaceutical Co., Ltd.) Water Dispersant: "DISPERBYK-145" manufactured by BYK-Chemie Dispersant: "DISPERBYK-106" manufactured by BYK-Chemie Pigment: cyanine blue Antifoaming agent: "Florene AC-2300C" manufactured by Kyoeisha Chemical Co., Ltd. Antioxidant: "SONGNOX1010" manufactured by Songwon

[0082] Example 1 A first part was prepared by mixing an organic polymer having a hydrolyzable silyl group (MS polymer SAT115, MS polymer SAX010), a plasticizer, aluminum hydroxides 1 to 4, water, a pigment, an antifoaming agent, and an antioxidant according to the formulation in Table 1. A second part was prepared by mixing a plasticizer, a dehydrating agent, an adhesion promoter, a silanol catalyst, and a dispersant according to the formulation in Table 1. The first and second parts prepared as described above were weighed into a 200 ml polypropylene container so that the total weight was 100 g at the volume ratio shown in Table 1. The contents of the container were stirred for 1 minute using a 15 mm wide polypropylene spatula at a rate of 2 revolutions per second, yielding a thermally conductive composition composed of the first and second parts.

[0083] [Examples 2 to 9, Comparative Examples 1 to 4] Thermally conductive compositions composed of a first part and a second part were obtained in the same manner as in Example 1, except that the types and amounts of each component were changed according to Tables 1 and 2.

[0084]

[0085] *The volume ratios of the mixtures in Tables 1 and 2 were calculated based on the composition and specific gravity of each agent.

[0086] The thermally conductive compositions of the above examples all met the specified requirements for the viscosity of the first and second components, as well as the viscosity after mixing the first and second components. Therefore, while the thermal conductivity was good, the sedimentation of the thermally conductive filler during storage of the first and second components was suppressed. Furthermore, the thermally conductive composition obtained by mixing the first and second components had good applicability and excellent flowability through narrow gaps. In contrast, the thermally conductive composition prepared in Comparative Example 1 exceeded the specified standards for both the viscosity of the second component and the viscosity after mixing the first and second components, failing to achieve good applicability. The thermally conductive compositions prepared in Comparative Examples 2 and 3 had an average particle size of the thermally conductive filler contained in the second component that exceeded the specified standard, and were unable to suppress sedimentation of the thermally conductive filler, at least in the second component, during storage of the first and second components. The thermally conductive composition prepared in Comparative Example 4 had a viscosity of the first part that was below the specified standard, and was unable to suppress the settling of the thermally conductive filler in at least the first part during storage of the first and second parts.

[0087] In Example 1, as shown in the graph in Figure 3, the viscosity after mixing the first and second parts was lower than the viscosity after mixing that was predicted from the respective viscosities of the first and second parts and the mixing ratio. The reason for this is unclear, but it is presumed to be because the second part had a higher resin content than the first part and because only the second part contained a dispersant. Similar trends were observed in the other examples.

[0088] 30 Syringe 31 First syringe 31A Discharge outlet of first syringe 32 Second syringe 32A Discharge outlet of second syringe 33A, 34A Barrel 33B, 34B Barrel lid 35, 45 First agent 36, 46 Second agent 38 Mixer 39 Discharge outlet of mixer 41 First pail 42 Second pail 43A, 44A Container body having opening 43B, 44B Lid for closing the opening of the container body

Claims

1. A two-component curing thermally conductive composition comprising: a first part containing at least one of a curable liquid resin and a plasticizer, and a thermally conductive filler, having a viscosity of 90 Pa·s or more and 1000 Pa·s or less, and filled in a first container; and a second part containing at least one of the curable liquid resin and the plasticizer, having a viscosity of 10 Pa·s or less, and filled in a second container, wherein at least one of the first part and the second part contains the curable liquid resin, the thermally conductive filler in the first part has an average particle size of 5 μm or more, the second part does not contain a thermally conductive filler or contains the thermally conductive filler with an average particle size of less than 5 μm, and the viscosity of the thermally conductive composition after mixing the first part and the second part is 1 Pa·s or more and less than 60 Pa·s.

2. The thermally conductive composition according to claim 1, wherein the curable liquid resin is an organic polymer having a hydrolyzable silyl group.

3. The thermally conductive composition according to claim 2, wherein the organic polymer having a hydrolyzable silyl group is a polyalkylene oxide having a hydrolyzable silyl group.

4. The thermally conductive composition according to claim 2, wherein at least one of the first part and the second part contains the plasticizer.

5. The thermally conductive composition according to claim 2, wherein either the first part or the second part contains water, and the other part contains a catalyst.

6. The thermally conductive composition according to claim 2, wherein the first part contains either water or a catalyst, and does not contain the other of water or a catalyst, and the second part does not contain an organic polymer having a hydrolyzable silyl group, and contains the other of water or a catalyst.

7. The thermally conductive composition according to claim 2, wherein the first part does not contain water or a catalyst, and the second part does not contain an organic polymer having a hydrolyzable silyl group, but contains water and a catalyst.

8. The thermally conductive composition according to claim 1 or 2, wherein the content of the thermally conductive filler is 10 to 80% by volume.

9. The thermally conductive composition of claim 1 or 2, wherein the thermally conductive filler comprises aluminum hydroxide.

10. The thermally conductive composition of claim 1 or 2, wherein the thermally conductive filler comprises aluminum oxide.

11. The thermally conductive composition according to claim 1 or 2, wherein the thermal conductivity of the cured product of the thermally conductive composition is 1.0 W / m·K or more.

12. A thermally conductive composition according to claim 1 or 2, wherein the difference in viscosity between the first part and the second part is 50 Pa·s or more.

13. A thermally conductive composition according to claim 1 or 2, wherein when the first agent and the second agent are mixed, the volume ratio of the first agent to the second agent is 95 / 5 to 70 / 30.

14. A thermally conductive composition according to claim 1 or 2, wherein the specific gravity of the first agent is greater than the specific gravity of the second agent.

15. A thermally conductive composition according to claim 1 or 2, wherein the resin content of the second agent is greater than the resin content of the first agent.

16. The thermally conductive composition according to claim 1 or 2, wherein the second agent contains a dispersant.

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