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

Technical Field

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

Background Art

[0002] Thermally conductive compositions containing thermally conductive fillers are widely known to be curable and liquid. For example, they are filled between a heat-generating body and a heat-dissipating body, and then cured to form a cured product, and are used as thermally conductive members such as heat-dissipation gap fillers that transfer the heat generated by the heat-generating body to the heat-dissipating body.

[0003] In recent years, in the market background where the production volume of electric vehicles (EVs) is growing smoothly, the demand for two-component room-temperature curable type heat-dissipation gap fillers for lithium-ion batteries (LiBs) is increasing. In lithium-ion batteries, from the perspective of heat dissipation, thermally conductive compositions are often filled between various members such as battery cells, battery modules, and battery packs for the purpose of fixing each member and enhancing heat dissipation.

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

[0005] Further, Patent Document 2 discloses an invention related to a thermally conductive silicone potting composition including a first member and a second member. The first member includes a vinyl organopolysiloxane, an alumina filler having a specific range of average particle size, a filler of aluminum hydroxide, and a catalyst, and the second member is disclosed to include a hydride organopolysiloxane, an alumina filler having a specific range of average particle size, and a filler of aluminum hydroxide. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Special Publication No. 2022-521790 [Patent Document 2] Special Publication No. 2022-536577 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] Incidentally, depending on the assembly method of electric vehicles, it may be desirable to inject a thermally conductive composition into the gap between the battery cells and battery modules after they have been pre-installed in the case. Furthermore, in recent years, there has been a demand for miniaturization of equipment, and the aforementioned gap has been made narrower. However, conventional thermally conductive compositions, such as those described in Patent Document 1, have high viscosity, making it difficult to adequately fill gaps when applied to battery applications. To address the above problem, it is conceivable to reduce the viscosity of the thermal conductive composition to the viscosity described in Patent Document 2. However, this would cause the thermal conductive filler to settle, and during storage of the thermal conductive composition, the thermal conductive filler would settle, forming a hard layer that is difficult to redisperse, resulting in the so-called hard cake problem.

[0008] Therefore, the object of the present invention is to provide a thermally conductive composition that has low viscosity during use but can suppress the sedimentation of thermally conductive fillers during storage. [Means for solving the problem]

[0009] As a result of diligent research, the inventors have found that the above problem can be solved by mixing a two-component curable thermal conductive composition, consisting of a first component containing a thermal conductive filler with a relatively large average particle size and adjusted to high viscosity, and a second component that does not contain a thermal conductive filler with a relatively large average particle size and adjusted to low viscosity, so that the mixture has a viscosity that allows it to be poured into narrow gaps. In other words, the present invention provides the following [1] to

[17] .

[0010] [1] A two-component curable thermal conductive composition comprising a first agent which comprises at least one of a curable liquid resin and a plasticizer and a thermal conductive filler, has a viscosity of 90 Pa·s or more and 1000 Pa·s or less, and is filled into a first container, and a second agent which comprises at least one of the curable liquid resin and the plasticizer, has a viscosity of 10 Pa·s or less, and is filled into a second container, wherein at least one of the first agent and the second agent comprises the curable liquid resin, the average particle size of the thermal conductive filler in the first agent is 5 μm or more, the second agent does not contain the thermal conductive filler or contains the thermal conductive filler with an average particle size of less than 5 μm, and the viscosity of the thermal conductive composition after mixing the first agent and the second agent is 1 Pa·s or more and less than 60 Pa·s. [2] The thermally conductive composition according to [1], wherein the curable liquid resin is an organic polymer having hydrolyzable silyl groups. [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], comprising a plasticizer in at least one of the first agent and the second agent. [5] A thermally conductive composition according to any one of the first or second agent, comprising water in one of them and a catalyst in the other, as described in any one of the items [2] to [4]. [6] The thermally conductive composition according to any one of [2] to [5], wherein the first agent comprises either water or a catalyst and not the other of water or a catalyst, and the second agent does not contain an organic polymer having a hydrolyzable silyl group and comprises either water or a catalyst. [7] The thermally conductive composition according to any one of [2] to [6], wherein the first agent does not contain water or a catalyst, and the second agent does not contain an organic polymer having a hydrolyzable silyl group, but contains water and a catalyst. [8] The thermal conductive composition according to any one of [1] to [7], wherein the content of the thermal conductive filler is 10 to 80 by volume. [9] The thermal conductive composition according to any one of [1] to [8], wherein the thermal conductive filler comprises aluminum hydroxide.

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

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

[10] , wherein the thermal conductivity of the cured product of the thermal 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 viscosity difference between the first agent and the second agent 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 agent to the second agent when the first agent and the second agent are mixed 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 agent is greater than the specific gravity of the second agent.

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

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

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

[15] , comprising a dispersant in the second agent.

[17] A method of using a two-component curable thermally conductive composition comprising 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 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 agent and the second agent contains the curable liquid resin, 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 contains the thermally conductive filler with an average particle diameter 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 and applied at a volume ratio of the first agent to the second agent (first agent / second agent) of 95 / 5 to 70 / 30.

Advantages of the Invention

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

Brief Description of the Drawings

[0012] [Figure 1] It is a schematic diagram showing a container set according to an embodiment. [Figure 2] It is a schematic diagram showing a container set according to another embodiment. [Figure 3] It 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.

Modes for Carrying Out the Invention

[0013] [Thermally Conductive Composition] The heat-conductive composition of the present invention is a two-component curable heat-conductive composition comprising a first agent and a second agent. The first agent contains at least one of a curable liquid resin and a plasticizer, and a heat-conductive filler, has a viscosity of 90 Pa·s or more and 1000 Pa·s or less, and is filled in a first container. The second agent 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 heat-conductive filler, or even if it contains a heat-conductive filler, the average particle size of the heat-conductive filler contained in the second agent is less than 5 μm, and is filled in a second container. And the viscosity of the heat-conductive composition obtained by mixing the first agent and the second agent (hereinafter, also referred to as "viscosity after mixing") is 1 Pa·s or more and less than 60 Pa·s.

[0014] In addition, in the heat-conductive composition of the present invention, the first agent filled in the first container and the second agent filled in the second container are stored without being mixed before use while being stored in the containers. By storing the first agent and the second agent separately in this way, it is possible to suppress the polymerization and curing of the curable liquid resin during storage, and the storage stability is enhanced. The first agent and the second agent are mixed at the time of use and used as a heat-conductive composition.

[0015] <Viscosity> In the present invention, as described above, the viscosity of the first agent is 90 Pa·s or more and 1000 Pa·s or less, the viscosity of the second agent is 10 Pa·s or less, and the viscosity after mixing is 1 Pa·s or more and less than 60 Pa·s. When the viscosity of the first agent is less than 90 Pa·s, the viscosity of the first agent becomes insufficient, and there is a risk of sedimentation of the heat-conductive filler. On the other hand, if the viscosity of the first agent exceeds 1000 Pa·s or the viscosity of the second agent exceeds 10 Pa·s, there is a risk that the viscosity after mixing cannot be made sufficiently low. Furthermore, if the viscosity after mixing is less than 1 Pa·s, it becomes difficult to incorporate a large amount of thermal conductive filler, which may lead to problems such as poor handling of the thermal conductive composition. Moreover, if the viscosity after mixing exceeds 60 Pa·s, the applicability of the thermal conductive composition deteriorates, making it difficult to fill narrow gaps inside battery modules and the like with the thermal conductive composition.

[0016] From the above viewpoint, the viscosity of the first agent 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. Furthermore, the viscosity of the second agent 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 agent 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 to 58 Pa·s, more preferably 2 Pa·s to 57 Pa·s, and even more preferably 3 Pa·s to 50 Pa·s. The above viscosity values ​​are all measured using a rheometer at 25°C and a shear rate of 3.16 (1 / sec), and further details are as described in the examples.

[0017] The thermal conductive composition of the present invention preferably has a viscosity difference of 50 Pa·s or more between the first and second components, more preferably 60 Pa·s or more, and even more preferably 80 Pa·s or more. When the viscosity difference is above the above lower limit, it suppresses the settling of the thermal conductive filler and makes it easier to adjust the viscosity after mixing to a certain level or lower. 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] <Thermally conductive filler> The thermally conductive composition of the present invention contains a thermally conductive filler in at least the first component, and the average particle size of the thermally conductive filler in the first component is 5 μm or larger. If the average particle size of the thermally conductive filler in the first component is less than 5 μm, it becomes difficult to improve the thermal conductivity of the thermally conductive composition. The second component may or may not contain a thermally conductive filler, but if it does contain one, its average particle size must be less than 5 μm. If the average particle size of the thermally conductive filler in the second component is 5 μm or larger, it becomes difficult to suppress sedimentation if the viscosity of the second component remains low. From the above viewpoints, 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, from the viewpoint of keeping the viscosity of the first agent below a certain level, 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. Furthermore, the average particle size of the thermally conductive filler in the second component is preferably 3 μm or less, more preferably 1 μm or less. It is also 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 components is the average particle size of all thermally conductive fillers contained in each component. In this specification, the average particle size is the median diameter (D50) value measured by a laser diffraction / scattering particle size distribution analyzer.

[0019] The content of the thermal conductive filler in the thermal conductive composition is preferably 10 to 80 volume%, more preferably 20 to 75 volume%, and even more preferably 35 to 72 volume%, based on the total volume of the thermal conductive composition. If the content of the thermal conductive filler is above the lower limit, the thermal conductivity of the thermal conductive composition tends to improve. Furthermore, if the content of the thermal conductive filler is below the upper limit, the viscosity of the thermal conductive composition can be adjusted to a certain level or lower, making it easier to fill the thermal conductive composition into narrow gaps inside battery modules and the like.

[0020] The content of the thermally conductive filler in the first component 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 component. By having a thermally conductive filler content in the first component that is above the above lower limit, the viscosity of the first component can be adjusted to a certain level or higher, making it easier to suppress the settling of the thermally conductive filler. Furthermore, from the viewpoint of making it easier to adjust the viscosity of the first component to a certain level or lower, the content of the thermally conductive filler in the first component 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 component.

[0021] The content of the thermal conductive filler in the second agent 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 agent. By keeping the content of the thermal conductive filler in the second agent below the above upper limit, the viscosity of the second agent can be adjusted to a certain level or less, making it easier to fill the narrow gaps inside battery modules and the like with the thermal conductive composition after mixing it with the first agent. The content of the thermal conductive filler in the second agent may be 0% by volume or more, but from the viewpoint of thermal conductivity, it may contain a certain amount of thermal conductive filler, in which case the content of the thermal 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 agent.

[0022] Examples of thermally conductive fillers include metals, metal oxides, metal nitrides, metal hydroxides, carbon materials, and non-metallic oxides, nitrides, and carbides. The thermally conductive fillers can take the form of spherical or amorphous powders. Examples of thermally conductive fillers include aluminum, copper, and nickel as metals, aluminum oxide (represented by alumina), magnesium oxide, and zinc oxide as metal oxides, and aluminum nitride as a metal nitride. Examples of metal hydroxides include aluminum hydroxide, magnesium hydroxide, and zinc hydroxide. Furthermore, examples of carbon materials include spheroidal graphite. Examples of oxides, nitrides, and carbides other than metals include quartz, boron nitride, silicon carbide, and silicon oxide such as silica. Among these, metal oxides, metal nitrides, metal hydroxides, carbon materials, and oxides, nitrides, and carbides other than metals are preferred from the viewpoint of ensuring insulation. In particular, it is preferable that the thermally conductive filler includes 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 includes an organic polymer having hydrolyzable silyl groups (described later), the reaction between the organic polymer having hydrolyzable silyl groups and the thermally conductive filler becomes easier. 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 enhanced. 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. As the metal hydroxide, aluminum hydroxide is preferred. It is preferable that the metal oxide and metal hydroxide are untreated. This is because surface treatment reduces the number of hydroxyl groups on the surface, making them less receptive to reaction with organic polymers. Therefore, untreated aluminum oxide is preferred as the metal oxide, and untreated aluminum hydroxide is preferred as the metal hydroxide. However, the present invention does not preclude the use of surface-treated thermal 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 thermal conductive filler.

[0023] The thermal conductive filler preferably contains a large-particle thermal conductive filler with an average particle size of 5 μm or more in the first component. Including a large-particle thermal conductive filler with an average particle size of 5 μm or more makes it easier to improve the thermal conductivity of the thermal conductive composition, makes it easier to adjust the viscosity of the first component to a certain level or higher, and makes it easier to suppress sedimentation of the thermal conductive composition. In the first component, as long as the average particle size of the entire thermal conductive filler is 5 μm or more, in addition to the large-particle thermal conductive filler, a small-particle thermal conductive filler with an average particle size of less than 5 μm may also be included. Furthermore, the second component may also contain a small-particle thermally conductive filler with an average particle size of less than 5 μm, as described above. The average particle size of the large-particle thermal conductive filler is preferably 5 μm to 200 μm, and more preferably 8 μm to 150 μm. The small-particle thermal conductive filler may have an average particle size of, for example, 10 nm to less than 5 μm, and preferably 50 nm to 4 μm. The large-particle thermally conductive filler is preferably at least one selected from aluminum hydroxide and aluminum oxide. Furthermore, the small-particle thermally conductive filler is preferably at least one selected from aluminum hydroxide, aluminum oxide, and silica. In addition, when the second component contains a small-particle thermally conductive filler, it is also preferable to use at least one selected from aluminum hydroxide and aluminum oxide and silica in combination as the small-particle thermally conductive filler. For use as a small-particle thermally conductive filler, powdered silica is preferred. The inclusion of powdered silica helps to suppress sedimentation of the thermally conductive filler. Examples of powdered silica include fumed silica, colloidal silica, and silica gel. Among these, fumed silica is preferred. Examples of fumed silica include Aerosil® from Nippon Aerosil Co., Ltd.

[0024] <Curable liquid resin> The thermally conductive composition of the present invention contains a curable liquid resin. Before mixing the first and second components, the curable liquid resin may be contained in either the first or second component, or in both the first and second components, but it is preferable that it be contained in the first component. The inclusion of the curable liquid resin in the first component helps to hold the thermally conductive filler in place, making it easier to suppress the sedimentation of the thermally conductive filler during storage.

[0025] Examples of curable liquid resins include urethane-based, silicone-based, epoxy-based, and organic polymers having hydrolyzable silyl groups. Among these, organic polymers having hydrolyzable silyl groups are preferred.

[0026] Here, an example of a urethane-based resin is one that consists of a polyol compound as the main component and a polyisocyanate compound as the curing agent. In this case, for example, the polyol compound as the main component may be included as the first component, and the polyisocyanate compound as the curing agent may be included as the second component. The silicone resin may be either a condensation-curing type silicone resin or an addition-curing type silicone resin, but an addition-curing type silicone resin is preferred. An addition-curing type silicone resin may consist of a silicone resin that constitutes the main component and a curing agent that cures the main component. For example, in the case of an addition-curing type silicone resin, an organopolysiloxane having an alkenyl group may be used as the main component, and an organohydrogenpolysiloxane may be used as the curing agent. When using an addition-curing type silicone resin, for example, the silicone resin, which is the main component, may be included in the first component, and the curing agent in the second component. Epoxy resins may consist of an epoxy group-containing compound as a main component and a curing agent. In this case, for example, the epoxy group-containing compound as the main component may be included in the first component, and the curing agent 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. As the curing agent constituting the epoxy resin, for example, at least one of amines and thiols can be used, and the use of amines is preferred. Furthermore, when using an epoxy resin, in addition to the epoxy group-containing compound, a polyfunctional acrylate compound may be further included as a main component. The polyfunctional acrylate compound may be included in the first component, similar to the epoxy group-containing compound. The following describes in detail the case where an organic polymer having hydrolyzable silyl groups is used as the curable liquid resin.

[0027] Organic polymers having hydrolyzable silyl groups can form siloxane bonds through condensation polymerization of silanol groups or between silanol groups and hydrolyzable silyl groups, after which hydrolysis by moisture such as humidity can form silanol groups. This causes the organic polymer to form a crosslinked structure, and upon curing, a rubber-like elastic material is obtained. A silanol group refers to a hydroxyl group (Si-OH) directly bonded to a silicon atom. Preferably, the hydrolyzable silyl group is an alkoxysilyl group, specifically trimethoxysilyl, dimethoxysilyl, triethoxysilyl, or diethoxysilyl group. On the other hand, polyethers such as polyalkylene oxides can be used as organic polymers.

[0028] A hydrolyzable silyl group is a group formed by bonding one to three hydrolyzable groups to a silicon atom. The hydrolyzable groups of a hydrolyzable silyl group are not particularly limited and include, for example, hydrogen atoms, halogen atoms, alkoxy groups, acyloxy groups, ketoximate groups, amino groups, amide groups, acid amide groups, aminooxy groups, mercapto groups, and alkenyloxy groups. Among the hydrolyzable silyl groups, alkoxysilyl groups are preferred because their hydrolysis reaction is mild. Examples of alkoxysilyl groups include trialkoxysilyl groups such as trimethoxysilyl, triethoxysilyl, triisopropoxysilyl, and triphenoxysilyl; dialoxysilyl groups such as dimethoxymethylsilyl and diethoxymethylsilyl; and monoalkoxysilyl groups such as methoxydimethylsilyl and ethoxydimethylsilyl. Among these, dialoxysilyl groups are more preferred, and dimethoxymethylsilyl groups are particularly preferred.

[0029] The organic polymer having hydrolyzable silyl groups may have a linear or branched main chain, but a linear main chain is preferred. In other words, the organic polymer having hydrolyzable silyl groups of the present invention preferably has hydrolyzable silyl groups at the ends of a linear main chain.

[0030] The terminal silylation rate of the organic polymer having hydrolyzable silyl groups is preferably 70% or more, more preferably 80% or more, and even more preferably 90% or more. When the terminal silylation rate is above a certain level, the thermally conductive composition can be sufficiently cured even when the content of the organic polymer having hydrolyzable silyl groups is low. The terminal silylation rate refers to the ratio of silylated ends to all ends of the organic polymer having hydrolyzable silyl groups. There is no particular upper limit on the terminal silylation rate, but for example, it should be 100% or less, and practically it can be 99% or less. Furthermore, the terminal silylation rate of organic polymers having hydrolyzable silyl groups is 1 It can be determined by 1H-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, it becomes possible to sufficiently cure the thermally conductive composition even when the content of the organic polymer having hydrolyzable silyl groups is low. Furthermore, as a method for measuring the average number of hydrolyzable silyl groups in one molecule of an organic polymer having hydrolyzable silyl groups, 1 It can be calculated based on the concentration of hydrolyzable silyl groups in the organic polymer determined by 1H-NMR and the number-average molecular weight of the polymer determined by GPC.

[0032] The method for introducing hydrolyzable silyl groups into organic polymers is not particularly limited, and examples include (1) hydrosilylation by reacting an organic polymer modified with an unsaturated group in its molecule with a hydrosilane having a hydrolyzable silyl group, (2) reacting an organic polymer modified with an unsaturated group in its molecule with a compound having a mercapto group and a hydrolyzable silyl group, and (3) reacting an organic polymer having a functional group in its molecule with a compound having a functional group that is reactive to this functional group and a hydrolyzable silyl group. Specifically, reactions between isocyanate groups and hydroxyl groups, reactions between isocyanate groups and amino groups, and reactions between isocyanate groups and mercapto groups can be used.

[0033] There are no particular limitations on the organic polymer having a hydrolyzable silyl group, and examples include polyalkylene oxides such as polyethylene oxide, polypropylene oxide, polybutylene oxide, polytetramethylene oxide, polyethylene oxide-polypropylene oxide copolymer, and polypropylene oxide-polybutylene oxide copolymer; saturated hydrocarbon polymers; copolymers of polychloroprene, polyisoprene, isoprene, or butadiene with acrylonitrile and / or styrene; copolymers of polybutadiene, 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; and vinegar. Examples include vinyl polymers obtained by radical polymerization of monomers such as vinyl acid, acrylonitrile, and styrene; graft polymers obtained by polymerizing vinyl monomers in 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 sebaciic 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 nylon having two or more components from the above nylons; 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 oxide is preferred as the organic polymer from the viewpoint of setting the viscosity of the thermally conductive composition to a desired range. That is, as the organic polymer having hydrolyzable silyl groups, polyalkylene oxide having hydrolyzable silyl groups is preferred. Among polyalkylene oxides, polypropylene oxide is particularly preferred.

[0035] The number-average molecular weight (Mn) of the organic polymer having hydrolyzable silyl groups 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. If the number-average molecular weight of the organic polymer having hydrolyzable silyl groups is below these upper limits, the viscosity of the resulting thermally conductive composition will be lower, making it easier to fill narrow gaps inside battery modules and the like. If the number-average molecular weight of the organic polymer having hydrolyzable silyl groups is above these lower limits, the settling of the thermally conductive filler will be more easily suppressed. Note that if the thermally conductive composition contains multiple types of organic polymers having hydrolyzable silyl groups, the number-average molecular weight (Mn) refers to the total number-average molecular weight (Mn) of all of them.

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

[0037] For polymers having hydrolyzable silyl groups, commercially available products can be used. For example, polyalkylene oxide polymers in which the main chain skeleton is polypropylene oxide and has dimethoxysilyl groups at the ends of the main chain skeleton include AGC Inc.'s products "Excestar A2410," "Excestar S4530," and "Excestar S6250," and Kaneka Corporation's products "S203," "SAT115," and "SAX010."

[0038] In the thermal conductive composition of the present invention, it is preferable that the resin content of the second component is greater than that of the first component. Specifically, the resin content of the second component is preferably 30% or more by volume than that of the first component, more preferably 40% or more by volume, and even more preferably 45% or more by volume, based on the total amount of each component. A higher resin content in the second component than in the first component allows the first component to contain more thermal conductive filler than the second component, making it easier to adjust the viscosity of the first and second components to a desired range. In this case, the difference between the resin content of the first component and the resin content of the second component is, for example, 85% or less by volume, preferably 80% or less by volume, and more preferably 75% or less by volume, based on the total amount of each component. In this specification, the resin content refers to the total volume ratio 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 component 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 component. Furthermore, the resin content in the second component 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 component.

[0040] <Plasticizer> The thermal conductive composition of the present invention preferably contains a plasticizer. The plasticizer may be contained in at least one of the first and second components, but it is preferable that it be contained in both the first and second components. By containing a plasticizer, the viscosity of the thermal conductive composition can be adjusted to below a certain level, making it easier to fill the thermal conductive composition into narrow gaps inside battery modules and the like. Furthermore, it is preferable to include a plasticizer, especially when the curable liquid resin contains an organic polymer having hydrolyzable silyl groups. Including a plasticizer together with the organic polymer having hydrolyzable silyl groups makes it easier to adjust the viscosity of the thermally conductive composition to a desired range.

[0041] 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 above plasticizer is preferably an organic ester plasticizer. Examples of the monobasic organic acid esters mentioned above include glycol esters obtained by the reaction of glycol with a monobasic organic acid. Examples of the glycols mentioned above include triethylene glycol, tetraethylene glycol, and tripropylene glycol. Examples of the monobasic organic acids mentioned above include butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, heptylic acid, n-octylic acid, 2-ethylhexyl acid, n-nonylic acid, decyl acid, and benzoic acid.

[0042] Examples of the above-mentioned polybasic organic acid esters include ester compounds of a polybasic organic acid and an alcohol having a linear or branched structure with 4 to 8 carbon atoms. Examples of the above-mentioned polybasic organic acids include adipic acid, sebacic acid, and azelaic acid. The above organic ester plasticizers include triethylene glycol di-2-ethyl propanoate, triethylene glycol di-2-ethyl butyrate, 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-ethyl butyrate, 1,3-propylene glycol di-2-ethyl butyrate, 1,4-butylene glycol di-2-ethyl butyrate, and diethylene glycol di-2-ethyl butyrate Examples include diethylene glycol di-2-ethylhexanoate, dipropylene glycol di-2-ethyl butyrate, triethylene glycol di-2-ethylpentanoate, tetraethylene glycol di-2-ethyl butyrate, 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 phosphate esters and adipic acid esters. Other organic ester plasticizers may also be used. Other adipic acid esters other than those listed above may also be used.

[0043] Examples of the organophosphorus plasticizers mentioned above include tributoxyethyl phosphate, isodecylphenyl phosphate, tris(2-ethylhexyl) phosphate, and triisopropyl phosphate. The above plasticizer is preferably a diester plasticizer represented by the following formula (1). [ka] In formula (1) above, 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 from 3 to 10. Preferably, R1 and R2 in formula (1) above are organic groups having 5 to 10 carbon atoms, and more preferably are organic groups having 6 to 10 carbon atoms. The above plasticizer preferably contains triethylene glycol di-2-ethylhexanoate (3GO), triethylene glycol di-2-ethyl butyrate (3GH), or triethylene glycol di-2-ethylpropanoate. The above plasticizer more preferably contains triethylene glycol di-2-ethylhexanoate (3GO) or triethylene glycol di-2-ethyl butyrate (3GH), and even more preferably contains triethylene glycol di-2-ethylhexanoate.

[0044] The molecular weight of the plasticizer is preferably less than 1000, more preferably less than 500, and preferably 50 or more, and more preferably 100 or more, from the viewpoint of reducing the viscosity of the first agent, the second agent, and the composition obtained by mixing them. Furthermore, the molecular weight of the plasticizer is preferably 50 or more and less than 1000, and more preferably 100 or more and less than 500.

[0045] The plasticizer content in the thermal 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 hydrolyzable silyl groups. If the amount of plasticizer is above these lower limits, the viscosity of the composition decreases, making it easier to suppress the settling of the thermal conductive filler. If the amount of plasticizer is below these upper limits, the amount of curable liquid resin can be kept above a certain level, so that a certain level of reaction points with the thermal conductive filler can be secured, especially when using a polymer having hydrolyzable silyl groups, making it easier to sufficiently cure the thermal conductive composition. In addition, the viscosity of the composition can be adjusted to below a certain level, making it easier to fill into narrow gaps inside battery modules and the like. The plasticizer may be included in at least one of the first and second components, but it is preferable that it be included in both the first and second components. When the plasticizer is included in both the first and second components, the mass ratio of the plasticizer content in the first component to the plasticizer content in the second component is often, 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 component within the above range, it becomes easier to adjust the viscosity of each component to a desired range.

[0046] <Catalyst> If at least one of the first and second components constituting the thermally conductive composition of the present invention contains a polymer having hydrolyzable silyl groups as a curable liquid resin, it is preferable to include a catalyst, and more preferably a silanol condensation catalyst. By including a catalyst, together with water as described later, the condensation reaction of the organic polymer having hydrolyzable silyl groups is promoted, and a cured product of a high-quality thermally conductive composition can be obtained.

[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-distanoxane, as well as organotitanium compounds such as tetra-n-butoxytitanate and tetraisopropoxytitanate. These silanol condensation catalysts may be used individually or in combination of two or more. Among the above, organotin compounds are preferred as silanol condensation catalysts.

[0048] The catalyst content in the thermally conductive composition is preferably 0.3 to 15 parts by mass, and more preferably 0.5 to 10 parts by mass, per 100 parts by mass of the organic polymer having hydrolyzable silyl groups. It is also preferable that the catalyst content in at least one of the first and second components be within this range. If the silanol condensation catalyst content is above these lower limits, the curing speed can be increased, and if the silanol condensation catalyst content is below these upper limits, the curing speed can be appropriately controlled.

[0049] <Water> Preferably, at least one of the first and second components constituting the thermally conductive composition of the present invention contains water. This is preferable because, after mixing the first and second components to prepare the thermally conductive composition, it can be rapidly cured throughout the composition. 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 hydrolyzable silyl groups. It is also preferable that the water content in at least one of the first and second components be within this range.

[0050] In the present invention, when the curable liquid resin includes a polymer having hydrolyzable silyl groups, it is preferable that either the first or second agent contains water and the other contains a catalyst. Furthermore, the first agent may contain either water or a catalyst, but not the other, and the second agent may not contain an organic polymer having a hydrolyzable silyl group, but may contain either water or a catalyst. In this case, the first agent may contain 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 incorporating the polymer having hydrolyzable silyl groups, water, and catalyst, polymerization and curing of the organic polymer having hydrolyzable silyl groups during storage of the first and second agents can be suppressed, thereby improving storage stability. Furthermore, the first agent may not contain water or a catalyst, and the second agent may not contain an organic polymer having a hydrolyzable silyl group, but may contain water and a catalyst.

[0051] <Dispersant> The thermal conductive composition of the present invention does not require the second component to contain a dispersant, but it is preferable that the second component contains a dispersant. By including a dispersant, after mixing the first and second components, the dispersant acts on the thermal conductive filler contained in the first component, allowing the thermal conductive filler to be properly dispersed in the composition. This allows the viscosity of the thermal conductive composition to be adjusted to below a certain level, making it easier to fill into narrow gaps inside battery modules and the like. Furthermore, the dispersant may or may not be included in the first component. By not including the dispersant in the first component, the viscosity of the first component can be adjusted to a certain level or higher, making it easier to suppress the settling of the thermally conductive filler. On the other hand, by including the dispersant in the first component, the viscosity reduction effect after mixing the first and second components can be enhanced.

[0052] Examples of dispersants include polymeric dispersants. Polymeric dispersants include polymer compounds having functional groups. Examples of polymer compounds include acrylic, vinyl, polyester, polyurethane, polyether, epoxy, polystyrene, amino, and silicone compounds. Examples of functional groups include carboxyl groups, phosphate groups, sulfonic acid groups, carboxylic acid ester groups, phosphate ester groups, sulfonic acid ester groups, hydroxyl groups, amino groups, quaternary ammonium bases, and amide groups. In addition, dispersants other than polymeric dispersants may be used; for example, alkoxysilane compounds may be used.

[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 hydrolyzable silyl groups. When the dispersant is contained only in the second component, 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 included in at least one of the first and second components, but from the viewpoint of storage stability, it is preferable that it is not included in the first component but included in the second component. Adhesion promoters can further improve the adhesion of thermally conductive compositions once they have cured.

[0055] As an adhesion promoter, aminosilane coupling agents are preferred. Specifically, examples of aminosilane coupling agents 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. Among these, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane is preferred.

[0056] The content of the adhesion promoter in the thermal conductive composition is preferably 1 to 20 parts by mass, and more preferably 1 to 15 parts by mass, per 100 parts by mass of the organic polymer containing hydrolyzable silyl groups. The content of the adhesion promoter in the second component is also preferably within this range. If the content of the adhesion promoter is above these lower limits, the adhesive strength of the formed cured product tends to improve, and if the content of the adhesion promoter is below these upper limits, it is possible to prevent the formed cured product 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 included in the component that does not contain water, but it is preferable that it be included only in the component. By including a dehydrating agent, it is possible to suppress hardening of the component 1 or 2 due to moisture contained in the air during storage. 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 zeolites. These dehydrating agents may be used alone or in combination of two or more. Among these, vinyltrimethoxysilane is preferred.

[0058] The amount of the dehydrating agent in the first or second agent is preferably 0.5 to 20 parts by mass, and more preferably 1 to 15 parts by mass, per 100 parts by mass of the hydrolyzable silyl group-containing organic polymer contained in the heat-conductive composition obtained by mixing the first and second agents. If the amount of the dehydrating agent is above these lower limits, hardening during storage is more easily suppressed, and if the amount of the dehydrating agent is below these upper limits, it is less likely that an increase in hardness over time due to the dehydrating agent will occur. Similarly, the content of the dehydrating agent in the thermally conductive composition is preferably 0.5 to 20 parts by mass, and more preferably 1 to 15 parts by mass, per 100 parts by mass of the organic polymer having a hydrolyzable silyl group.

[0059] <Other ingredients> The first agent and the second agent in the present invention, as well as the thermally conductive composition obtained by mixing them, may contain other additives such as antioxidants, ultraviolet absorbers, defoaming agents, pigments, dyes, settling inhibitors, and solvents.

[0060] <Volume ratio and specific gravity of the first and second components> When mixing the first and second agents, 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 in a higher proportion than the second agent in this way, it becomes easier to maintain high thermal conductivity after mixing.

[0061] Furthermore, it is preferable that the specific gravity of the first agent is greater than that of the second agent. Specifically, the specific gravity of the first agent is preferably 0.2 or more greater than that of the second agent, more preferably 0.3 or more greater, and even more preferably 0.5 or more greater. Having a higher specific gravity for the first agent than for 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 or more and 3 or less, preferably 1.75 or more and 2.5 or less, and more preferably 1.9 or more and 2.2 or less. Furthermore, the specific gravity of the second agent is preferably 0.3 to 1.8, preferably 0.5 to 1.5, and 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. Integrating the first and second containers facilitates supply to customers as a container set. In this specification, the first container filled with the first agent and the second container filled with the second agent are collectively referred to as a container set.

[0064] Examples of containers include syringes and cartridges, but are not limited to these. For example, when filling a syringe, a two-component parallel type syringe is preferable. As shown in Figure 1, the two-component parallel type syringe 30 consists of a first syringe 31 constituting the first container and a second syringe 32 constituting the second container, which are arranged in parallel and integrated. The first agent 35 and the second agent 36 filled in syringes 31 and 32 are preferably mixed by being dispensed from the syringe using the syringe as a dispenser.

[0065] Furthermore, when cartridges are used, the container set consists of a first cartridge constituting the first container and a second cartridge constituting the second container, and these cartridges may be integrated. Typically, the cartridges are set in syringes (for example, a first syringe and a second syringe), and the first agent dispensed from the first cartridge and the second agent dispensed from the second cartridge are dispensed from the respective nozzles of the first and second syringes, using each syringe as a dispenser, and mixed.

[0066] The first and second components are preferably mixed using a mixer such as a static mixer. The static mixer 38 is connected, for example, to the discharge port 31A of the first syringe 31 and the discharge port 32A of the second syringe 32, as shown in Figure 1, and the first component 35 and the second component 36 discharged from each discharge port 31A and 32A are made mixable inside the mixer. The mixture (thermal conductive composition) obtained by mixing in the mixer 38 is preferably discharged from the discharge port 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 are filled are closed with lids 33B, 34B. In the syringe 30 shown in Figure 1, the first agent 35 and the second agent 36 may be pushed out by a piston (not shown) inserted through the opening after the lids 33B, 34B are removed, and discharged from the respective discharge ports 31A, 32A.

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

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

[0069] [Application] The thermally conductive composition of the present invention can be used in a variety of applications. While the composition can suppress the settling of the thermally conductive filler during storage of the first and second components, the viscosity after mixing the first and second components remains below a certain level, making it particularly suitable for use as a gap filler for narrow spaces. Specific applications include, for example, use as a gap filler in batteries, electronic devices, semiconductor devices, etc., and it is preferably used in battery applications. When used in battery applications, the gap filler made of the thermally conductive composition is filled between battery cells, between battery cells and battery module cases, between battery cells and battery pack cases, between battery cells and cooling plates, between battery module cases and cooling plates, and between battery pack cases and cooling plates. The filled gap filler should adhere closely to the battery cells, battery module cases, battery pack cases, or cooling plates. This allows the gap filler between battery cells to maintain the 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, battery pack case, or cooling plate, and has the function of transferring the heat generated by the battery cell to the battery module case, battery pack case, or cooling plate. The thermally conductive composition, when used in battery applications, is not particularly limited, but is preferably used in two-wheeled vehicles, three-wheeled vehicles, and automobiles, and more preferably in two-wheeled vehicles, three-wheeled vehicles, and automobiles equipped with lithium-ion batteries. [Examples]

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

[0071] In this example, the evaluation was performed using the following method.

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

[0073] [Suppression of subsidence] The sedimentation inhibition of each of the two components was evaluated after preparation and 168 hours at 35°C. The evaluation criteria are as follows. A: Two layers were not separated after 168 hours at 35°C. B: After 168 hours at 35°C, the mixture had separated into two layers, but it could be redispersed by shaking it by hand. C: After 168 hours at 35°C, two layers had separated and could not be redispersed even by shaking by hand. The combined evaluation results for the first solution and the second agent are also shown in Tables 1 and 2. The combined evaluation results show the worse of the two evaluation results for the first solution and the second agent in terms of sedimentation inhibition.

[0074] [Applicability] For application, a viscosity cup with an 8mm diameter conforming to the DIN53211 standard (DKSHG, model number 321 / No.5) was used. 50g of the thermal conductive composition prepared by the method described in the examples was placed in the cup, and the amount dispensed over one minute was measured. The evaluation criteria are as follows: A: The discharge volume was 25g or more. B: The amount dispensed was 0.5g or more but less than 25g. C: The amount dispensed was less than 0.5g.

[0075] [Thermal conductivity] The thermal conductivity of the cured products obtained by curing the thermally conductive compositions prepared in each example and comparative example at 25°C and 50%RH for two weeks was measured. The thermal conductivity was determined by measuring thermal resistance using a measuring device compliant with ASTM D5470-06. Specifically, hardened materials with thicknesses of 1.0 mm, 1.5 mm, and 2.0 mm were prepared, and their thermal resistance and thickness were measured when compressed at a pressure of 30 psi. For these three thermal resistance values, a graph was created with thickness on the horizontal axis and thermal resistance on the vertical axis, and an approximate straight line was found at three points using the least squares method. The slope of this approximate straight line then represents the thermal conductivity. Thermal resistance was measured at 80°C using the "LW-9389" instrument manufactured by Long Win Science and Technology Corporation. The thermal conductivity of the thermally conductive composition was evaluated based on the thermal conductivity measured by the above method. The evaluation criteria are as follows: A:1.0W / m·K or more B: 0.8 W / m·K or higher, less than 1.0 W / m·K C: Less than 0.8

[0076] [comprehensive evaluation] The lowest result among the evaluations for settling suppression, applicability, and thermal conductivity was adopted as the overall evaluation.

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

[0078] <Organic polymer having hydrolyzable silyl groups> • Kaneka Corporation's "MS Polymer SAT115," a linear type organic polymer with a number-average molecular weight of 3,400, a terminal silylation rate of 60%, and dimethoxymethylsilyl groups at both ends of a polypropylene oxide molecule. • Kaneka Corporation's "MS Polymer SAX010," a linear type organic polymer with a number-average molecular weight of 2,400, a terminal silylation rate of 94%, and dimethoxymethylsilyl groups at both ends of a polypropylene oxide molecule. • AGC's "Excestar S6250," a 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%, an organic polymer having dimethoxymethylsilyl groups at both ends of branched polypropylene oxide.

[0079] <Thermally conductive filler> • Aluminum hydroxide 1 (average particle size 1 μm) • Aluminum hydroxide 2 (average particle size 10 μm) • Aluminum hydroxide 3 (average particle size 50 μm) • Aluminum hydroxide 4 (average particle size 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 BIC Chemie Inc. • Dispersant: "DISPERBYK-106" manufactured by BIC Chemie Inc. Pigment: Cyanine blue • Antifoaming agent: "Florence AC-2300C" manufactured by Kyoeisha Chemical Co., Ltd. • Antioxidant: Songwon "SONGNOX1010"

[0082] [Example 1] According to the formulations in Table 1, the first component was prepared by mixing an organic polymer having a hydrolyzable silyl group (MS Polymer SAT115, MS Polymer SAX010), a plasticizer, aluminum hydroxide 1-4, water, a pigment, an antifoaming agent, and an antioxidant. The second component was also prepared by mixing a plasticizer, a dehydrating agent, an adhesion promoter, a silanol catalyst, and a dispersant, according to the formulations in Table 1. The first and second components prepared as described above were weighed into a 200 ml polypropylene container so that the total amount was 100 g in 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 speed of 2 rotations per second to obtain a thermally conductive composition composed of the first and second components.

[0083] [Examples 2-9, Comparative Examples 1-4] A thermally conductive composition comprising the first and second components was obtained in the same manner as in Example 1, except that the type and amount of each component were changed according to Tables 1 and 2.

[0084] [Table 1]

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

[0086] The thermal conductive compositions of the above examples all met the required requirements in terms of the viscosity of the first and second components, as well as the viscosity after mixing the first and second components. Therefore, while exhibiting good thermal conductivity, the settling of the thermal conductive filler was suppressed during storage of the first and second components, and the thermal conductive composition obtained by mixing the first and second components had good coatability and excellent flowability in narrow gaps. In contrast, the thermally conductive composition prepared in Comparative Example 1 had viscosity levels exceeding the predetermined standard for both the second component and the mixture of the first and second components, and therefore could not be obtained with good coating properties. In the thermally conductive compositions prepared in Comparative Examples 2 and 3, the average particle size of the thermally conductive filler contained in the second component exceeded a predetermined standard, and the settling of the thermally conductive filler in at least the second component could not be suppressed during storage of the first and second components. In Comparative Example 4, the viscosity of the first component of the thermally conductive composition was below a predetermined standard, and during storage of the first and second components, the sedimentation of the thermally conductive filler, at least in the first component, could not be suppressed.

[0087] In Example 1, as shown in the graph in Figure 3, the viscosity after mixing the first and second agents was lower than the viscosity expected from the individual viscosities and mixing ratio of the first and second agents. The reason for this is unclear, but it is presumed that the second agent had a higher resin content compared to the first agent, and that the dispersant was contained only in the second agent. A similar trend was observed in the other examples. [Explanation of Symbols]

[0088] 30 syringes 31. First syringe 31A First syringe nozzle 32 Second syringe 32A Second syringe nozzle 33A, 34A barrel 33B, 34B barrel cover 35, 45 First agent 36, 46 Second agent 38 Mixer 39 Mixer outlet 41. The first pail 42. Second pail 43A, 44A Container body with opening 43B, 44B Lids that close the opening of the container body

Claims

1. A first agent comprising 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, which is filled into a first container, A two-component curable thermal conductive composition comprising a second agent which contains at least one of the curable liquid resin and the plasticizer, has a viscosity of 10 Pa·s or less, and is filled into a second container, At least one of the first agent and the second agent contains the curable liquid resin, The average particle size of the thermally conductive filler in the first agent is 5 μm or more. The second agent either does not contain a thermally conductive filler or contains a thermally conductive filler with an average particle size of less than 5 μm. The thermally conductive filler in the first agent comprises at least one selected from aluminum hydroxide and aluminum oxide with an average particle size of 8 μm or more and 150 μm or less, and at least one selected from aluminum hydroxide and aluminum oxide with an average particle size of 50 nm or more and 4 μm or less. The content of the thermally conductive filler in the first agent is 45% by volume or more and 90% by volume or less. The content of the thermally conductive filler in the second agent is 25% by volume or less. If the second agent includes the thermally conductive filler, the thermally conductive filler contained in the second agent includes at least one selected from aluminum hydroxide and aluminum oxide with an average particle size of 0.05 μm or more and 3 μm or less. The curable liquid resin in the first agent comprises a polyalkylene oxide having a hydrolyzable silyl group, The first agent contains water and does not contain a catalyst, and the second agent contains the catalyst and does not contain water, or the first agent contains the catalyst and does not contain water, and the second agent contains water and does not contain a catalyst. Both the first agent and the second agent contain the plasticizer, wherein the plasticizer is a glycol ester with a molecular weight of 50 or more and less than 1000. A thermally conductive composition having a viscosity of 1 Pa·s or more and less than 60 Pa·s after mixing the first agent and the second agent.

2. The thermal conductive composition according to claim 1, wherein the content of the thermal conductive filler is 10 to 80 volume percent.

3. The thermally conductive composition according to claim 1 or 2, wherein the thermally conductive filler comprises aluminum hydroxide.

4. The thermal conductive composition according to claim 1 or 2, wherein the thermal conductive filler comprises aluminum oxide.

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

6. The thermally conductive composition according to claim 1 or 2, wherein the viscosity difference between the first agent and the second agent is 50 Pa·s or more.

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

8. The 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.

9. The 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.

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

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