Thermal Conductive Composition, Two-Component Curing Thermal Conductive Material, Supply Form of Two-Component Curing Thermal Conductive Material, and Battery Module

Abstract

A thermally conductive composition according to the present invention comprises: at least one curable compound selected from the group consisting of an epoxy compound and an epoxy curing agent; a thermally conductive filler; and a structural viscosity imparting agent, wherein the viscosity ratio (η1 / η3) of the viscosity η1 measured by a rheometer under the conditions of a measurement temperature of 25°C and a shear rate of 0.0001 (1 / s) to the viscosity η3 measured under the conditions of a measurement temperature of 25°C and a shear rate of 0.0251 (1 / s) is at least 60.　The present invention can provide a thermally conductive composition which is capable of minimizing the settling of the thermally conductive filler during storage and which has excellent handling properties during use.

Description

Technical Field

[0001] The present invention relates to a thermally conductive composition, a two-component curable thermally conductive material, a supply form of the two-component curable thermally conductive material, and a battery module.

Background Art

[0002] A cured product formed by filling a thermally conductive composition containing a thermally conductive filler between a heat-generating body and a heat-radiating body and then curing it is used as a thermally conductive member that transmits heat generated by the heat-generating body to the heat-radiating body. Since the thermally conductive composition has fluidity, it can fill any gap between the heat-generating body and the heat-radiating body. Therefore, even if the gap between the heat-generating body and the heat-radiating body is not constant, the gap can be surely filled, and it is used as a spacer material in battery modules and the like. In addition, the thermally conductive member formed of the thermally conductive composition can be disposed between a battery cell as a heat-generating body and a module housing as a heat-radiating body and used for radiating the heat of the battery cell to the outside. It is also used to dispose between battery cells and fix them to maintain a separated state. Such thermally conductive compositions are generally desired to have workability that can be discharged from a cartridge or a syringe at a sufficient speed, storage stability that does not cause sedimentation of the thermally conductive filler (filler) during storage, compressibility (handleability) that does not apply stress when pressed against an object to be used such as a battery cell, and sufficient thermal conductivity and adhesiveness after curing.

[0003] Patent Document 1 describes an invention related to a thermally conductive composition including a trifunctional or higher functional epoxy resin (epoxy compound) having no aromatic skeleton, a liquid difunctional or lower functional epoxy compound, a curing agent, a silane compound having no functional group other than an alkoxy group, and a specific thermally conductive filler, as a thermally conductive composition having high thermal conductivity.

Prior Art Documents

Patent Documents

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2022-116587 [Summary of the Invention] [Problems to be Solved by the Invention]

[0005] In a thermally conductive composition containing an epoxy compound and a thermally conductive filler as in the invention described in Patent Document 1, when a low-viscosity epoxy compound is used to improve workability and handleability, sedimentation of the thermally conductive filler occurs during storage, or liquid phase separation of the epoxy compound occurs, causing problems such as quality degradation. Therefore, an object of the present invention is to provide a thermally conductive composition containing a curable compound selected from an epoxy compound and an epoxy curing agent and a thermally conductive filler, which can suppress sedimentation of the thermally conductive filler during storage and has excellent handleability during use. [Means for Solving the Problems]

[0006] The present inventors conducted intensive studies to solve the above problems. As a result, a thermally conductive composition containing at least one curable compound selected from the group consisting of an epoxy compound and an epoxy curing agent, a thermally conductive filler, and a structure viscosity imparting agent, and having a viscosity ratio under specific conditions measured by a rheometer of 60 or more was found to solve the above problems, and the present invention was completed. That is, the present invention provides the following [1] to

[14] .

[0007] [1] A thermally conductive composition containing at least one curable compound selected from the group consisting of an epoxy compound and an epoxy curing agent, a thermally conductive filler, and a structure viscosity imparting agent, and having a viscosity ratio (η1 / η3) of 60 or more between a viscosity η1 measured at a measurement temperature of 25°C and a shear rate of 0.0001 (1 / s) and a viscosity η3 measured at a measurement temperature of 25°C and a shear rate of 0.0251 (1 / s) by a rheometer. [2] The thermally conductive composition according to [1] above, wherein the viscosity η2 measured under the conditions of a measurement temperature of 25°C and a shear rate of 25.1 (1 / s) is 125 Pa·s or less. [3] The thermally conductive composition according to [1] or [2] above, wherein the structure viscosity-imparting agent is a compound having a melting point exceeding 25°C. [4] The thermally conductive composition according to any one of [1] to [3] above, wherein the structure viscosity-imparting agent is an ester compound having a melting point exceeding 25°C and 120°C or less. [5] The thermally conductive composition according to any one of [1] to [4] above, wherein the curable compound is an epoxy compound. [6] The thermally conductive composition according to any one of [1] to [4] above, wherein the curable compound is an epoxy curing agent. [7] The thermally conductive composition according to [6] above, wherein the epoxy curing agent is an amine compound. [8] A two-component curable thermally conductive material, which is a combination of a first agent comprising the thermally conductive composition according to [5] above and a second agent comprising the thermally conductive composition according to [6] above. [9] A first container filled with a first agent comprising a thermally conductive composition containing an epoxy compound, a thermally conductive filler, and a structure viscosity-imparting agent, A combination with a second container filled with a second agent comprising a thermally conductive composition containing an epoxy curing agent, a thermally conductive filler, and a structure viscosity-imparting agent, A supply form of a two-component curable thermally conductive material, wherein the viscosity ratio (η1 / η3) of the viscosity η1 measured under the conditions of a measurement temperature of 25°C and a shear rate of 0.0001 (1 / s) and the viscosity η3 measured under the conditions of a measurement temperature of 25°C and a shear rate of 0.0251 (1 / s) for each of the first agent and the second agent is 60 or more, as measured by a rheometer.

[10] A thermally conductive member which is a cured product of the thermally conductive composition according to any one of [1] to [7] above.

[11] A thermally conductive member which is a cured product of the two-component curable thermally conductive material according to [8] above.

[12] A battery module comprising a spacer made of the heat conductive member described in

[10] or

[11] above, a plurality of battery cells, and a module housing for storing the plurality of battery cells, wherein the spacer is disposed inside the module housing.

[13] A method for producing a thermally conductive composition, comprising the steps of preparing a mixture containing at least one curable compound selected from the group consisting of an epoxy compound and an epoxy curing agent, a thermally conductive filler, and a structure viscosity imparting agent, heating the mixture, and cooling the mixture to adjust the viscosity ratio (η1 / η3) of the viscosity η1 of the mixture measured by a rheometer under the conditions of a measurement temperature of 25°C and a shear rate of 0.0001 (1 / s) and the viscosity η3 of the mixture measured under the conditions of a measurement temperature of 25°C and a shear rate of 0.0251 (1 / s) to 60 or more.

[14] A method for producing a supply form of a thermally conductive composition, comprising the steps of preparing a mixture containing at least one curable compound selected from the group consisting of an epoxy compound and an epoxy curing agent, a thermally conductive filler, and a structure viscosity imparting agent, filling the mixture into a container, heating the mixture, and cooling the mixture to adjust the viscosity ratio (η1 / η3) of the viscosity η1 of the mixture measured by a rheometer under the conditions of a measurement temperature of 25°C and a shear rate of 0.0001 (1 / s) and the viscosity η3 of the mixture measured under the conditions of a measurement temperature of 25°C and a shear rate of 0.0251 (1 / s) to 60 or more.

Advantages of the Invention

[0008] According to the present invention, it is possible to provide a thermally conductive composition that can suppress sedimentation of the thermally conductive filler during storage and has excellent handleability during use.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0010] [Thermally Conductive Composition] Hereinafter, the thermally conductive composition of the present invention will be described in detail. The thermally conductive composition of the present invention includes at least one curable compound selected from the group consisting of an epoxy compound and an epoxy curing agent, a thermally conductive filler, and a structure viscosity imparting agent. And, the viscosity ratio (η1 / η3) of the thermally conductive composition of the present invention, measured at a measurement temperature of 25°C and a shear rate of 0.0001 (1 / s) by a rheometer, and the viscosity η3 measured at a measurement temperature of 25°C and a shear rate of 0.0251 (1 / s) is 60 or more.

[0011] [Viscosity Ratio] The thermally conductive composition of the present invention has a viscosity ratio (η1 / η3) measured by a rheometer of 60 or more. When the viscosity ratio (η1 / η3) is less than 60, when storing the thermally conductive composition, the thermally conductive filler is likely to settle, and the handleability during use is likely to deteriorate. The handleability during use means physical properties corresponding to the compressibility evaluated in the examples described later. From the viewpoint of suppressing the sedimentation of the thermally conductive filler during storage and improving the handleability during use, the viscosity ratio (η1 / η3) of the thermally conductive composition measured by a rheometer is preferably 70 or more, more preferably 80 or more, still more preferably 100 or more, and even more preferably 140 or more. The upper limit value of the viscosity ratio (η1 / η3) is not particularly limited, but is, for example, 500. The adjustment of the viscosity ratio (η1 / η3) will be described in detail later. Since the heat-conductive composition contains a structure-viscosity imparting agent and a gentle bond (internal structure) due to the cohesive force described later is formed through heating and cooling treatment, the viscosity ratio (η1 / η3) measured by a rheometer becomes 60 or more. In this specification, the range indicated by "~" means the range from a predetermined numerical value equal to or greater than the value described before "~" to a predetermined numerical value equal to or less than the value described after "~".

[0012] Although the reason why suppressing the sedimentation of the heat-conductive filler during storage of the heat-conductive composition and improving the handleability during use can be achieved by adjusting the viscosity ratio (η1 / η3) as described above is not clear, it is presumed as follows. Both the viscosity η1 and the viscosity η3 represent the viscosity in the low shear rate region. When the viscosity ratio (η1 / η3) of the heat-conductive composition is 60 or more, the change in viscosity with respect to the change in shear rate in the low shear rate region becomes large. In other words, the slope of the graph representing the relationship between the shear rate (horizontal axis) and the viscosity (vertical axis) becomes large. This means that in the storage state, that is, when the shear rate is extremely small, the viscosity of the heat-conductive composition increases, and therefore it is considered that the sedimentation of the heat-conductive filler is suppressed. And when using after placing it in the storage state, for example, when applying the heat-conductive composition with a dispenser or compressing the coated material, the shear rate becomes relatively high. At this time, as the shear rate increases, the viscosity of the heat-conductive composition effectively decreases, so it is considered to have excellent handleability.

[0013] In the present invention, since it is important to adjust the viscosity ratio (η1 / η3) as described above, the individual values of the viscosity η1 and the viscosity η3 are not particularly limited. However, from the viewpoint of suppressing the sedimentation of the heat-conductive filler, the viscosity η1 is, for example, 50,000 Pa·s or more, preferably 100,000 Pa·s or more, more preferably 500,000 Pa·s or more, and still more preferably 1,000,000 Pa·s or more. The upper limit of the viscosity η1 is not particularly limited, but is, for example, 5,000,000 Pa·s.

[0014] Furthermore, the viscosity η2 measured at a measurement temperature of 25°C and a shear rate of 25.1 (1 / s) by a rheometer of the thermally conductive composition is preferably 125 Pa·s or less, more preferably 100 Pa·s or less, and even more preferably 80 Pa·s or less from the viewpoints of enhancing compressibility and improving handleability. The lower limit of the η2 is not particularly limited, but for example, it is 10 Pa·s.

[0015] The viscosities η1, η2, and η3 of the thermally conductive composition are values measured by a rheometer at 25°C. When measuring with a rheometer, from the viewpoint of evaluating excluding the influence of shear when setting the sample in the measurement jig, after heating the thermally conductive composition, it shall be cooled to room temperature (25°C) for measurement. At this time, the heating temperature shall be a temperature equal to or higher than the melting point of the structure viscosity-imparting agent, preferably equal to or lower than the melting point of the structure viscosity-imparting agent + 50°C. The heating temperature may be appropriately set, for example, in the range of 35 to 170°C. The details of the measurement conditions of the rheometer will be described in the examples. The viscosities η1, η2, and η3 of the thermally conductive composition, the viscosity ratio (η1 / η3), etc. can be adjusted by the types and amounts of the structure viscosity-imparting agent and the thermally conductive filler described later.

[0016] <Structure viscosity-imparting agent> The thermally conductive composition of the present invention contains a structure viscosity-imparting agent. The structure viscosity-imparting agent is preferably a compound that is solid at room temperature (25°C), and by blending this with the curable compound described later and placing it under specific conditions, the viscosity can be increased. Specifically, the structure viscosity-imparting agent has a function of increasing the viscosity in the low shear region compared to the state before heating by blending and mixing this with the curable compound and heating and cooling. The structure viscosity-imparting agent is preferably a compound with a melting point exceeding 25°C, more preferably a compound with a melting point of 40°C or higher, and even more preferably a compound with a melting point of 45°C or higher. Also, the structure viscosity-imparting agent is preferably a compound with a melting point of 120°C or lower, more preferably a compound with a melting point of 100°C or lower, and even more preferably a compound with a melting point of 85°C or lower.

[0017] By mixing a curable compound and a structure-viscosity imparting agent at room temperature, heating the mixture above the melting point of the structure-viscosity imparting agent, and then cooling it to room temperature, a loose bond (internal structure) is formed in the mixture of the curable compound and the structure-viscosity imparting agent. This loose bond is formed by the cohesive force of the structure-viscosity imparting agent and is not broken by gravity. Therefore, it is considered that sedimentation of the thermal conductivity filler during storage can be suppressed. And during use, since a shear force of a certain level or more is applied to the mixture, the above-mentioned loose bond is broken, resulting in a decrease in viscosity and an improvement in workability such as coatability and compressibility. In other words, the internal structure is a structure formed by the cohesive force of the structure-viscosity imparting agent, and thereby the viscosity in the low shear region is increased. Here, the cohesive force means the action in which compounds of the same kind of structure stick to each other and attract each other. Also, this loose bond is formed during the process of cooling from a state heated above the melting point. Furthermore, the loose bond is broken by shear stress. Therefore, the loose bond is broken when shear stress occurs after cooling and can be formed again by heat treatment of heating and cooling. Also, in order to exhibit the above functions, it is preferable that the structure-viscosity imparting agent does not separate from the curable compound for a certain period of time when heated to a liquid state.

[0018] The thermal conductive composition of the present invention contains a structure-viscosity imparting agent, which makes it easier to adjust to the above-mentioned viscosity or viscosity ratio. As the structure-viscosity imparting agent, those having the above functions can be used without particular limitation. Specific examples of the structure-viscosity imparting agent are preferably an ester compound that is solid at 25°C (hereinafter also referred to as ester compound X) or an alcohol compound that is solid at 25°C. Among them, an ester compound that is solid at 25°C is more preferable. The melting point of ester compound X is preferably above 25°C, more preferably 40°C or higher, and still more preferably 45°C or higher. Also, the melting point of ester compound X is preferably 120°C or lower, more preferably 100°C or lower, and still more preferably 85°C or lower. When the structured viscosity-imparting agent is the ester compound X having such a melting point, it becomes easier to adjust the viscosity ratio (η1 / η3) to the desired range described above, suppress sedimentation of the heat-conductive filler during storage, and easily obtain a heat-conductive composition excellent in handleability during use. The melting point of the ester compound X is determined from the temperature of the peak of the endothermic curve of the ester compound in measurement by a differential scanning calorimeter (DSC). Specifically, for the heat-conductive composition of the present invention containing the ester compound X, measurement is performed by a differential scanning calorimeter (DSC), and the peak temperature of the endothermic curve accompanying melting of the ester compound is taken as the melting point of the ester compound X.

[0019] The ester compound X is a compound having an ester group, and may be a monoester having one ester group, or may be one having two or more ester groups such as a diester, but is preferably a monoester or a diester. The number of carbon atoms of the ester compound X is not particularly limited as long as the ester compound X is solid at 25°C. For example, it is 20 or more, preferably 25 or more, more preferably 28 or more, and preferably 150 or less, more preferably 100 or less, and even more preferably 50 or less.

[0020] The ester compound X is preferably an ester of a fatty acid and an alcohol. The number of carbon atoms of the fatty acid is preferably 2 to 30, more preferably 10 to 24. The number of carbon atoms of the fatty acid means the total number of carbon atoms including the carbonyl carbon of the carboxyl group. The alcohol may be an alcohol having one hydroxyl group, or an alcohol having two or more hydroxyl groups. The number of carbon atoms of the alcohol is preferably 2 to 30, more preferably 4 to 24. Examples of the ester compound X include cetyl myristate, pentaerythritol distearate, myristyl myristate, myristyl stearate, stearyl stearate, behenyl behenate, glycerin monostearyl ester, ethylene glycol distearyl ester, and the like. Among them, as the ester compound X, at least one selected from the group consisting of myristyl myristate, stearyl stearate, and behenyl behenate is preferable. The ester compound X may be used alone or in combination of two or more.

[0021] When using an alcohol compound that is solid at 25°C as the structure viscosity-imparting agent, the melting point of the alcohol compound is preferably above 25°C, more preferably 30°C or higher, and even more preferably 40°C or higher. Also, the melting point of the alcohol compound is preferably 120°C or lower, more preferably 80°C or lower, and even more preferably 75°C or lower. When the structure viscosity-imparting agent is an alcohol compound having such a melting point, it becomes easier to adjust the viscosity ratio (η1 / η3) to the desired range described above, suppress the sedimentation of the thermal conductive filler during storage, and easily obtain a thermal conductive composition having excellent handleability during use.

[0022] The alcohol compound is a compound having a hydroxy group, and may be a monoalcohol having one hydroxy group or a compound having two or more hydroxy groups such as a dialcohol, but a monoalcohol is preferable. The number of carbon atoms of the alcohol compound is not particularly limited as long as the alcohol compound is solid at 25°C. For example, it is 14 or more, preferably 16 or more, more preferably 18 or more, and preferably 40 or less, more preferably 36 or less, and even more preferably 30 or less. Also, the number of carbon atoms of the alcohol compound is preferably, for example, 14 to 40, more preferably 16 to 36, and even more preferably 18 to 30. As the alcohol compound, myristyl alcohol, cetyl alcohol, stearyl alcohol, nonadecyl alcohol, arachidyl alcohol, heneicosanol, behenyl alcohol, lignoceryl alcohol, cerotinyl alcohol, montanyl alcohol, myricyl alcohol, 1-docosanol, gedyl alcohol and the like are preferable. The alcohol compound may be used alone or in combination of two or more kinds. Regarding the structure viscosity-imparting agent, from the viewpoint of excellent storage stability, the ester compound X is preferable to the alcohol compound.

[0023] The content of the structure viscosity-imparting agent in the thermally conductive composition is preferably 0.5 part by mass or more, more preferably 3 parts by mass or more, still more preferably 6 parts by mass or more, and preferably 25 parts by mass or less, more preferably 20 parts by mass or less with respect to 100 parts by mass of the curable compound. Also, the content of the structure viscosity-imparting agent in the thermally conductive composition is preferably 0.5 to 20 parts by mass, more preferably 3 to 20 parts by mass, still more preferably 6 to 20 parts by mass with respect to 100 parts by mass of the curable compound.

[0024] <Curable compound> The thermally conductive composition of the present invention contains a curable compound, and the curable compound is at least one selected from an epoxy compound and an epoxy curing agent. The curable compound is a compound that is liquid at room temperature (25°C). The epoxy curing agent is used to cure the epoxy compound, and the epoxy compound and the epoxy curing agent react and cure when mixed. Therefore, although details will be described later, it is preferable to separate the epoxy compound and the epoxy curing agent and contain them in separate thermally conductive compositions for storage, and mix the separate thermally conductive compositions during use. The thermally conductive composition containing the epoxy compound becomes a thermally conductive composition having appropriate adhesiveness by mixing with the thermally conductive composition containing the epoxy curing agent.

[0025] (Epoxy compound) The epoxy compound may be any compound having one or more epoxy groups. The epoxy compound may be a polyfunctional epoxy compound having two or more epoxy groups, or may be a monofunctional epoxy compound having one epoxy group.

[0026] When the thermally conductive composition contains an epoxy compound, it is preferably contained at least a polyfunctional epoxy compound. By containing a polyfunctional epoxy compound, crosslinking can be appropriately formed, and it becomes easy to increase the adhesive strength. More preferably, the thermally conductive composition further contains a monofunctional epoxy compound in addition to the polyfunctional epoxy compound. By further containing a monofunctional epoxy compound in the thermally conductive composition, it is possible to prevent the crosslinking density after curing from becoming too high, and it becomes easy to increase the elongation. In addition, by using a monofunctional epoxy compound, it becomes easy to lower the viscosity of the thermally conductive composition before curing.

[0027] When a polyfunctional epoxy compound and a monofunctional epoxy compound are used in combination, the mass ratio of the monofunctional epoxy compound to the polyfunctional epoxy compound (monofunctional / polyfunctional) is preferably 10 / 90 or more and 90 / 10 or less, more preferably 15 / 85 or more and 75 / 25 or less, and even more preferably 25 / 75 or more and 50 / 50 or less.

[0028] Examples of the polyfunctional epoxy compound include bifunctional or trifunctional ones, and preferably a bifunctional epoxy compound is used. Specific examples of the polyfunctional epoxy compound include, but are not limited to, phenolic novolak type epoxy compounds, resorcinol type epoxy compounds, epoxy compounds having a bisphenol skeleton, epoxy compounds having a naphthalene skeleton, epoxy compounds having a fluorene skeleton, epoxy compounds having a biphenyl skeleton, epoxy compounds having a bis(glycidyloxyphenyl)methane skeleton, epoxy compounds having a xanthene skeleton, epoxy compounds having an anthracene skeleton, epoxy compounds having a pyrene skeleton, and other epoxy compounds having an aromatic ring. In addition, epoxy compounds having an alicyclic skeleton such as an epoxy compound having a dicyclopentadiene skeleton and an epoxy compound having an adamantane skeleton are also included. Furthermore, aliphatic epoxy compounds such as butanediol diglycidyl ether and neopentyl glycol diglycidyl ether are also included. In addition, hydrogenated products or modified products of the above-exemplified epoxy compounds can also be used as epoxy compounds.

[0029] Examples of the epoxy compound having the above-mentioned bisphenol skeleton include epoxy compounds having a bisphenol A-type, bisphenol F-type or bisphenol S-type bisphenol skeleton. Examples of the above-mentioned resorcinol-type epoxy compound include resorcinol diglycidyl ether. Examples of the epoxy compound having the above naphthalene skeleton include 1,2-diglycidylnaphthalene, 1,5-diglycidylnaphthalene, 1,6-diglycidylnaphthalene, 1,7-diglycidylnaphthalene, 2,7-diglycidylnaphthalene, triglycidylnaphthalene, and 1,2,5,6-tetraglycidylnaphthalene. Examples of the epoxy compound having the above fluorene skeleton include 9,9-bis(4-glycidyloxyphenyl)fluorene, 9,9-bis(4-glycidyloxy-3-methylphenyl)fluorene, 9,9-bis(4-glycidyloxy-3-chlorophenyl)fluorene, 9,9-bis(4-glycidyloxy-3-bromophenyl)fluorene, 9,9-bis(4-glycidyloxy-3-fluorophenyl)fluorene, 9,9-bis(4-glycidyloxy-3-methoxyphenyl)fluorene, 9,9-bis(4-glycidyloxy-3,5-dimethylphenyl)fluorene, 9,9-bis(4-glycidyloxy-3,5-dichlorophenyl)fluorene, and 9,9-bis(4-glycidyloxy-3,5-dibromophenyl)fluorene.

[0030] Examples of the epoxy compound having the biphenyl skeleton include 4,4'-diglycidyl biphenyl, 4,4'-diglycidyl-3,3',5,5'-tetramethyl biphenyl, and the like. Examples of the epoxy compound having the bis(glycidyloxyphenyl)methane skeleton include 1,1'-bis(2,7-glycidyloxynaphthyl)methane, 1,8'-bis(2,7-glycidyloxynaphthyl)methane, 1,1'-bis(3,7-glycidyloxynaphthyl)methane, 1,8'-bis(3,7-glycidyloxynaphthyl)methane, 1,1'-bis(3,5-glycidyloxynaphthyl)methane, 1,8'-bis(3,5-glycidyloxynaphthyl)methane, 1,2'-bis(2,7-glycidyloxynaphthyl)methane, 1,2'-bis(3,7-glycidyloxynaphthyl)methane, and 1,2'-bis(3,5-glycidyloxynaphthyl)methane, and the like.

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

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

[0033] Among the above multi-functional epoxy compounds, from the viewpoints of improving the adhesive strength and mechanical strength, epoxy compounds having an aromatic ring are preferable, and among them, epoxy compounds having a phenyl group are more preferable, and among them, bisphenol-type epoxy compounds which are epoxy compounds having a bisphenol skeleton are even more preferable. The multi-functional epoxy compound may be used alone or in combination of two or more kinds.

[0034] As the monofunctional epoxy compound, from the viewpoint of high raw material safety, aliphatic monofunctional epoxy compounds are preferable, and specifically, glycidyl ethers of aliphatic alcohols and the like can be mentioned. Here, as the aliphatic alcohol, those having a branched structure or a linear structure may be used, but from the viewpoint of improving elongation, a linear structure is preferable. Further, as the aliphatic alcohol, for example, it may have about 4 to 24 carbon atoms, but from the viewpoint of improving elongation, it preferably has 10 to 20 carbon atoms. Further, from the viewpoint of improving elongation, the aliphatic alcohol is preferably a saturated aliphatic alcohol. Specific examples of the glycidyl ether of the aliphatic alcohol include butyl glycidyl ether, decyl glycidyl ether, lauryl glycidyl ether, myristyl glycidyl ether, cetyl glycidyl ether, stearyl glycidyl ether and the like. The monofunctional epoxy compound may be other than the above, and for example, monofunctional epoxy compounds having a glycidyl group and not having an ether group such as 1,2-epoxybutane and propylene oxide can also be mentioned. As the monofunctional epoxy compound, from the viewpoint of improving elongation, it is preferable to use an aliphatic monofunctional epoxy compound, and among them, it is preferable to use a glycidyl ether of an aliphatic alcohol.

[0035] As the monofunctional epoxy compound, a monofunctional epoxy compound having an aromatic ring may be used. Examples of the monofunctional epoxy compound having an aromatic ring include phenyl glycidyl ethers such as alkyl phenyl glycidyl ethers typified by phenyl glycidyl ether, 4-t-butylphenyl glycidyl ether, cresyl glycidyl ether, and nonylphenyl glycidyl ether, and 1-glycidylnaphthalene, 2-glycidylnaphthalene, and the like. As the monofunctional epoxy compound having an aromatic ring, an epoxy compound having a phenyl group is more preferable. The monofunctional epoxy compound may be used alone or in combination of two or more.

[0036] The epoxy compound preferably contains an epoxy compound having an aromatic ring, particularly a phenyl group. The epoxy compound having an aromatic ring such as a phenyl group may be a monofunctional epoxy compound or a polyfunctional epoxy compound. An aromatic ring, particularly a phenyl group, takes a stacking structure after curing, and the epoxy compound is likely to form a pseudo-crosslinked structure in the cured product. Therefore, the mechanical strength is likely to be high and the adhesive strength is also likely to be high. The epoxy compound preferably contains a polyfunctional epoxy compound, and the polyfunctional epoxy compound preferably has an aromatic ring, particularly a phenyl group.

[0037] For the epoxy compound, those having a molecular weight of 2000 or less are preferably used, more preferably 1000 or less, and still more preferably 500 or less. By using an epoxy compound having a molecular weight below a certain value, the viscosity of the thermal conductivity composition can be lowered, and it is also possible to highly fill the thermal conductivity filler. The molecular weight of the epoxy compound is, for example, 100 or more, preferably 150 or more, more preferably 200 or more, and still more preferably 250 or more. By setting the molecular weight of the epoxy compound to be above a certain value, it is possible to prevent the crosslinking density from becoming too high and to make it easier to obtain good elongation.

[0038] The epoxy equivalent of the epoxy compound is preferably 1000 g / eq or less, more preferably 500 g / eq or less, still more preferably 375 g / eq or less, and is also preferably 100 g / eq or more, more preferably 125 g / eq or more, still more preferably 140 g / eq or more.

[0039] The epoxy compound is preferably liquid at room temperature (25°C). Also, from the viewpoint of reducing the viscosity, the lower the viscosity of the epoxy compound at 25°C, the better. For example, it may be 50 Pa·s or less, preferably 10 Pa·s or less. Also, the viscosity of the epoxy compound at 25°C is not particularly limited, but may be, for example, 0.5 mPa·s or more, or 1 mPa·s or more. Also, the viscosity of the polyfunctional epoxy compound at 25°C may be, for example, 50 Pa·s or less, preferably 10 Pa·s or less, and may be 1 mPa·s or more, but practically, it is preferably 10 mPa·s or more, and more preferably 100 mPa·s or more.

[0040] On the other hand, the viscosity of the monofunctional epoxy compound at 25°C may be, for example, 10 Pa·s or less, preferably 1 Pa·s or less, more preferably 100 mPa·s or less, and may be, for example, 0.5 mPa·s or more, or 1 mPa·s or more, or 3 mPa·s or more. When the epoxy compound contains both a polyfunctional epoxy compound and a monofunctional epoxy compound, the viscosity of the monofunctional epoxy compound is preferably lower than that of the polyfunctional epoxy compound. The viscosities of the epoxy compound and the amine compound described below are viscosities measured using an E-type viscometer under the conditions of 10 rpm and 25°C.

[0041] (Epoxy curing agent) The epoxy curing agent is not particularly limited as long as it is a compound capable of curing an epoxy compound. Examples include amine compounds, thiol compounds, acid anhydride-based compounds, epoxy curing catalysts, and the like. Among these, amine compounds are preferred from the viewpoints of ease of adjusting the reactivity with the epoxy compound, maintaining a low compressive load at the initial stage of curing, and being able to extend the pot life when the epoxy compound and the polyfunctional acrylate compound are used in combination as described later.

[0042] 〔Amine Compound〕 An amine compound is a compound having an amino group. The number of amino groups in the amine compound is not particularly limited, but is preferably 2 or more. By having 2 or more amino groups, the amine compound can react appropriately with the epoxy compound and cure. The number of amino groups is not particularly limited, but is, for example, 10 or less, preferably 6 or less, more preferably 4 or less. By setting the number of amino groups to a certain value or less as described above, it is possible to prevent the curing reaction from proceeding too far and to easily extend the pot life. Also, from the viewpoint of rapid curability, the number of amino groups is preferably 3 or more. Also, from the balance between the pot life and the rapid curability, the number of amino groups in the amine compound is preferably 2 or more and 10 or less, more preferably 3 or more and 6 or less, and even more preferably 3 or more and 4 or less.

[0043] The amino group possessed by the amine compound may be a primary amino group or a secondary amino group. From the viewpoints of reactivity and curing rate, the amine compound preferably has a primary amino group. The amine compound preferably has 1 or more primary amino groups in one molecule, more preferably 2 or more, and even more preferably 3 or more. By having many primary amino groups in the amine compound, rapid curability can be achieved. The number of primary amino groups in one molecule of the amine compound is, for example, 6 or less, preferably 5 or less, more preferably 4 or less. Further, the number of primary amino groups in one molecule of the amine compound is preferably 2 or more and 6 or less, more preferably 3 or more and 5 or less, still more preferably 3 or more and 4 or less, from the balance between the pot life and the rapid curability. Note that the amine compound having a primary amino group may have only a primary amino group, or may have a primary amino group and an amino group of secondary or higher order.

[0044] The viscosity of the amine compound is preferably 20 Pa·s or less. When the viscosity is 20 Pa·s or less, the viscosity before curing becomes low, and the workability can be improved. The viscosity of the amine compound is preferably 15 Pa·s or less, more preferably 12 Pa·s or less, still more preferably 5 Pa·s or less, and even more preferably 2 Pa·s or less. Further, the viscosity of the amine compound is not particularly limited, but is, for example, 0.005 Pa·s or more, preferably 0.01 Pa·s or more, more preferably 0.025 Pa·s or more, still more preferably 0.05 Pa·s or more.

[0045] As the amine compound, it is preferable to use one having an oxyalkylene structure. When using one having an oxyalkylene structure, due to its molecular structure, the compressive load in the initial stage of curing is moderately low, it is relatively easy to maintain in a state of low compressive load for a relatively long time, and it is easy to lengthen the pot life. The oxyalkylene structure preferably has a structure having oxyalkylene with about 2 to 5 carbon atoms, more preferably having an oxypropylene structure. Examples of the oxyalkylene structure include polyoxyalkylene structures in which two or more oxyalkylene structures are consecutive. Specifically, polyoxyethylene structure, polyoxypropylene structure, polyoxybutylene structure, polyoxytetramethylene structure, oxyethylene-oxypropylene copolymer structure, and oxypropylene-oxybutylene copolymer structure can be mentioned. Among these, the amine compound preferably has a polyoxypropylene structure, an oxyethylene-oxypropylene copolymer structure, and an oxypropylene-oxybutylene copolymer structure, and among them, it preferably has a polyoxypropylene structure.

[0046] Examples of the amine compound having an oxyalkylene structure usually include aliphatic amines. Specifically, polyoxyethylene diamine, poly(oxyethylene / oxypropylene) diamine, poly(oxypropylene) diamine, poly(oxybutylene / oxypropylene) diamine, polyethylene glycol bis(propylamine), trimethylolpropane poly(oxypropylene) triamine, polyoxyalkylene polyamines such as glyceryl poly(oxypropylene) triamine can be mentioned. Among these, poly(oxypropylene) diamine, glyceryl poly(oxypropylene) triamine, and trimethylolpropane poly(oxypropylene) triamine are preferable, and among them, trimethylolpropane poly(oxypropylene) triamine is more preferable.

[0047] In addition, as the amine compound having no oxyalkylene structure, an aliphatic amine, an aromatic ring-containing amine, or an amidoamine may be used. Specific examples of the aliphatic amine include, but are not limited to, branched or linear alkanediamines such as 1,3-diaminopropane, 2-methyl-1,5-diaminopentane, trimethylhexamethylenediamine, 2-methylpentamethylenediamine, and diethylaminopropylamine, and alicyclic polyamines such as 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, cyclohexanediamine, methylcyclohexanediamine, and isophoronediamine. As the amidoamine, any type may be used as long as it has a low viscosity. As the aromatic ring-containing amine, an amine in which an amino group is not directly bonded to an aromatic ring, such as m-xylylenediamine or a reaction product of m-xylylenediamine and styrene, or an aromatic amine in which an amino group is directly bonded to an aromatic ring may be used. As the amine compound having no oxyalkylene structure, an aromatic ring-containing amine in which an amino group is not directly bonded to an aromatic ring, such as a reaction product of m-xylylenediamine and styrene, or an aliphatic diamine is preferable in order to moderately increase the curing rate and enable it to have a certain compressive load in the initial stage of curing.

[0048] Among the above, as the amine compound, an aliphatic amine or an aromatic ring-containing amine in which an amino group is not directly bonded to an aromatic ring is preferable from the viewpoints of ensuring rapid curability and a certain compressive load in the initial stage of curing, and polyoxyalkylene polyamines are more preferable. The amine compound may be used alone or in combination of two or more.

[0049] The molecular weight of the amine compound is not particularly limited. For example, it may be 5000 or less, preferably 3000 or less, more preferably 1000 or less, and even more preferably 600 or less. By using an amine compound with a molecular weight below a certain value, the viscosity of the thermally conductive composition can be lowered, and it becomes possible to highly fill the thermally conductive filler. Also, for the molecular weight of the amine compound, for example, those with a molecular weight of 100 or more, preferably 110 or more, more preferably 200 or more, and even more preferably 300 or more may be used. By setting the molecular weight of the above amine compound to a certain value or more, the compressive load in the initial stage of curing can be moderately lowered, and it is possible to prevent the crosslinking density from becoming too high, making it easier to improve elongation and adhesive strength. Note that the amine compound is preferably liquid at room temperature (25°C). Note that the molecular weights of the amine compound and the above-mentioned epoxy compound can be measured, for example, with a mass spectrometer (GC-MS or LC-MS).

[0050] The active hydrogen equivalent of the amine compound is not particularly limited. For example, it is 15 g / eq or more, preferably 25 g / eq or more, more preferably 40 g / eq or more, and also, for example, 1000 g / eq or less, preferably 600 g / eq or less, more preferably 300 g / eq or less, and even more preferably 150 g / eq or less.

[0051] [Epoxy curing agent other than amine compound] The thermally conductive composition of the present invention may contain an epoxy curing agent other than an amine compound as an epoxy curing agent. Examples of epoxy curing agents other than amine compounds include thiol compounds, acid anhydride-based compounds, and epoxy curing catalysts.

[0052] The thiol compound is not particularly limited. For example, trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptobutyrate), trimethylolpropane tris(3-mercaptobutyrate), trimethylolethane tris(3-mercaptobutyrate), etc. may be mentioned. These may be used alone or in combination of two or more.

[0053] Examples of the acid anhydride-based compound include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, succinic anhydride, etc. These may be used alone or in combination of two or more. When using an acid anhydride-based compound, it is preferable to use it in combination with an epoxy curing catalyst described later.

[0054] Examples of the epoxy curing catalyst include imidazole-based curing catalysts, organic phosphorus-based curing catalysts, amine-based curing catalysts, tin catalysts, etc. When using an epoxy curing catalyst, it is also preferable to use it in combination with a plasticizer, that is, to dilute it with a plasticizer and use it. As the plasticizer, those that are liquid at room temperature (25°C) are preferable. Specific examples of the plasticizer include ester-based oils and hydrocarbon-based oils such as paraffin oil.

[0055] The thermally conductive composition of the present invention contains an epoxy compound or an epoxy curing agent as the curable compound as described above. The content of the curable compound in the thermally conductive composition is not particularly limited, but is preferably 3 to 80% by mass, more preferably 5 to 50% by mass, and still more preferably 8 to 20% by mass based on the total amount of the thermally conductive composition.

[0056] <Polyfunctional acrylate compound> The thermally conductive composition of the present invention preferably contains a polyfunctional acrylate compound. The polyfunctional acrylate compound is a compound having 2 or more functional groups (i.e., the number of (meth)acryloyl groups). In the present invention, by containing a polyfunctional acrylate compound, the thermally conductive composition reacts rapidly with an amine compound, has rapid curability, and a certain adhesive strength is imparted at the initial stage of curing. As the polyfunctional acrylate compound, various (meth)acrylates can be used, and preferably, it is a polyfunctional diol and an ester of (meth)acrylic acid. In addition, in this specification, the "(meth)acryloyl group" means either an acryloyl group or a methacryloyl group, the "(meth)acrylate" means either an acrylate or a methacrylate, and the same applies to other similar terms.

[0057] Among the polyfunctional acrylate compounds, examples of bifunctional ones include 1,3 - butanediol di(meth)acrylate, 1,4 - butanediol di(meth)acrylate, 1,6 - hexanediol di(meth)acrylate, 1,9 - nonanediol di(meth)acrylate, 1,10 - decanediol di(meth)acrylate, 2 - n - butyl - 2 - ethyl - 1,3 - propanediol di(meth)acrylate, dimethyloltricyclodecane di(meth)acrylate, ethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, ethylene oxide - added bisphenol A di(meth)acrylate, propylene oxide - added bisphenol A di(meth)acrylate, ethylene oxide - added bisphenol F di(meth)acrylate, dimethylol dicyclopentenyl di(meth)acrylate, ethylene oxide - modified isocyanuric acid di(meth)acrylate, 2 - hydroxy - 3 - (meth)acryloyloxypropyl (meth)acrylate, carbonate diol di(meth)acrylate, polyether diol di(meth)acrylate, polyester diol di(meth)acrylate, polycaprolactone diol di(meth)acrylate, polybutadiene diol di(meth)acrylate, and the like.

[0058] Among polyfunctional acrylate compounds, those with three or more functional groups include, for example, trimethylolpropane tri(meth)acrylate, glycerin tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, alkylene oxide-added trimethylolpropane tri(meth)acrylate such as ethylene oxide-added trimethylolpropane tri(meth)acrylate and propylene oxide-added trimethylolpropane tri(meth)acrylate, caprolactone-modified trimethylolpropane tri(meth)acrylate, ethylene oxide-added isocyanuric acid tri(meth)acrylate, propylene oxide-added glycerin tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, alkylene oxide-added pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tripentaerythritol octa(meth)acrylate, tetrapentaerythritol deca(meth)acrylate, tripentaerythritol hepta(meth)acrylate, tetrapentaerythritol nona(meth)acrylate, and the like.

[0059] The number of functional groups of the polyfunctional acrylate compound is preferably 3 or more, more preferably 4 or more, and even more preferably 6 or more. When the number of functional groups of the polyfunctional acrylate compound increases, the rapid curability is enhanced, and the adhesive strength in the initial stage of curing tends to increase. The upper limit of the number of functional groups of the polyfunctional acrylate compound is not particularly limited, and may be, for example, 10 or less, or 8 or less.

[0060] From the viewpoint of enhancing rapid curability and reducing the viscosity of the thermally conductive composition before curing, the molecular weight of the polyfunctional acrylate compound is preferably below a certain level. For example, the molecular weight of a specific polyfunctional acrylate compound may be 5000 or less, preferably 3000 or less, more preferably 1000 or less, and even more preferably 700 or less. Also, for the molecular weight of the polyfunctional acrylate compound, for example, those of 150 or more, preferably 200 or more, more preferably 250 or more, and even more preferably 450 or more may be used. By setting the molecular weight of the above polyfunctional acrylate compound to be above a certain value, the compressive load in the initial stage of curing can be moderately reduced, and it can be prevented that the crosslink density becomes excessively high, making it easier to improve elongation and adhesion. From the viewpoint of easily reducing the viscosity of the thermally conductive composition before curing, the polyfunctional acrylate compound is preferably liquid at room temperature (25°C).

[0061] The functional group equivalent of the polyfunctional acrylate compound is not particularly limited, but is preferably 500 g / eq or less, more preferably 300 g / eq or less, and even more preferably 150 g / eq or less. Also, it is preferably 75 g / eq or more, more preferably 80 g / eq or more, and even more preferably 85 g / eq or more.

[0062] In the thermally conductive composition, the ratio of the number of functional groups of the polyfunctional acrylate compound to the number of functional groups of the epoxy compound may be about 0.1 or more and 2.5 or less, preferably 0.3 or more and 1.5 or less, more preferably 0.6 or more and 1.2 or less, and even more preferably 0.75 or more and 1.1 or less. When the ratio of the number of functional groups of the polyfunctional acrylate compound is within a predetermined range, in the initial stage, the amine compound and the polyfunctional acrylate compound are preferentially cured, and rapid curability is exhibited. On the other hand, the reaction between the amine compound and the epoxy compound is suppressed, so the compressive load in the initial stage of curing is maintained low, and the pot life can be extended.

[0063] The content of the polyfunctional acrylate compound is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, still more preferably 40 parts by mass or more, and preferably 100 parts by mass or less, more preferably 80 parts by mass or less, still more preferably 60 parts by mass or less, based on 100 parts by mass of the curable compound. When the content of the polyfunctional acrylate compound is at least these lower limit values, rapid curability is likely to be exhibited, and the adhesive strength in the initial stage of curing can be increased. When the content of the polyfunctional acrylate compound is at most these upper limit values, it is possible to prevent the initial curing from progressing too much and to easily maintain a low initial compressive load.

[0064] When the thermally conductive composition contains a polyfunctional acrylate, it may further contain water. By containing water, for example, the reaction between the polyfunctional acrylate and the amine compound is promoted, and rapid curability can be easily obtained. The water content is not particularly limited, but for example, it is preferably about 0.3% by mass or more and 2.0% by mass or less based on the total amount of the thermally conductive composition.

[0065] <Thermally conductive filler> The thermally conductive composition of the present invention contains a thermally conductive filler. By containing the thermally conductive filler, the thermal conductivity of the thermally conductive composition and the thermally conductive member obtained from the thermally conductive composition is improved. Examples of the thermally conductive filler include metals, metal oxides, metal nitrides, metal hydroxides, carbon materials, oxides, nitrides, and carbides other than metals. The shape of the thermally conductive filler includes spherical and amorphous powders. In the heat conductive filler, examples of metals include aluminum, copper, nickel, etc.; examples of metal oxides include aluminum oxide typified by alumina, magnesium oxide, zinc oxide, etc.; examples of metal nitrides include aluminum nitride, etc. An example of the metal hydroxide is aluminum hydroxide. Further, examples of the carbon material include spherical graphite, diamond, etc. Examples of oxides, nitrides, and carbides other than metals include quartz, boron nitride, silicon carbide, etc. Among these, as the heat conductive filler, aluminum oxide and aluminum hydroxide are preferable, and aluminum hydroxide is more preferable. The heat conductive filler may be used alone or in combination of two or more.

[0066] The average particle size of the heat conductive filler is preferably 0.1 to 200 μm, more preferably 0.3 to 120 μm, and even more preferably 0.5 to 100 μm. The heat conductive filler is preferably used in combination of a small particle size heat conductive filler having an average particle size of 0.1 μm or more and 5 μm or less and a large particle size heat conductive filler having an average particle size of more than 5 μm and 200 μm or less. By using heat conductive fillers with different average particle sizes, the filling rate can be increased. Note that the average particle size of the heat conductive filler can be measured by observing with an electron microscope or the like. More specifically, for example, using an electron microscope or an optical microscope, the particle sizes of 50 arbitrary heat conductive fillers can be measured, and the average value (arithmetic mean value) can be taken as the average particle size.

[0067] The content of the heat conductive filler is preferably 150 to 3000 parts by mass, more preferably 300 to 2000 parts by mass, and even more preferably 500 to 1000 parts by mass with respect to 100 parts by mass of the curable compound. By setting the content of the heat conductive filler to be not less than the above lower limit value, a certain heat conductivity can be imparted to the heat conductive composition and the heat conductive member. By setting the content of the heat conductive filler to be not more than the above upper limit value, the heat conductive filler can be appropriately dispersed. Also, it is possible to prevent the viscosity of the heat conductive composition from becoming too high.

[0068] <Settling inhibitor> The heat conductive composition of the present invention may contain a settling inhibitor as long as the viscosity ratio (η1 / η3) is within a range not deviating from the above desired range. By containing a settling inhibitor, it becomes easier to suppress the settling of the heat conductive filler during storage. Examples of the settling inhibitor include waxes such as amide wax and hydrogenated castor oil wax, and silicas such as fumed silica. Among them, amide wax is preferable and fatty acid amide wax is more preferable because it suppresses the settling of the heat conductive filler during storage and also has good compressibility of the heat conductive composition. Note that fatty acid amide wax is a compound having a long-chain fatty acid group and an amide group in the molecule. The content of the settling inhibitor is not particularly limited, but based on the total amount of the heat conductive composition, it is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and preferably 3% by mass or less, more preferably 1% by mass or less. Also, the content of the settling inhibitor is preferably 0.01 to 3% by mass, more preferably 0.05 to 1% by mass, based on the total amount of the heat conductive composition.

[0069] <Dispersant> The heat conductive composition of the present invention may contain a dispersant. Examples of the dispersant include polymer dispersants. Examples of the polymer dispersant include polymer compounds having functional groups. Examples of the polymer compound include acrylic, vinyl, polyester, polyurethane, polyether, epoxy, polystyrene, amino, silicone, etc. Examples of the functional group include carboxyl group, phosphate group, sulfonic acid group, carboxylic acid ester group, phosphate ester group, sulfonic acid ester group, hydroxyl group, amino group, quaternary ammonium base, amide group, etc. Also, a dispersant other than the polymer dispersant may be used, for example, an alkoxysilane compound may be used. The content of the dispersant in the heat conductive composition is preferably 0.01 part by mass or more and 10 parts by mass or less, more preferably 0.05 part by mass or more and 5 parts by mass or less, and even more preferably 0.1 part by mass or more and 3 parts by mass or less, based on 100 parts by mass of the curable compound.

[0070] <Other additives> In the thermally conductive composition of the present invention, other additives other than the above-mentioned sedimentation inhibitors and dispersants can be contained. Examples of other additives include flame retardants, antioxidants, colorants, and the like.

[0071] <Form of supply of the thermally conductive composition> In the present invention, the above-mentioned thermally conductive composition can also provide a form of supply of the thermally conductive composition filled in a container. Examples of the container include syringes, cartridges, pails, and drums.

[0072] <Method for producing the thermally conductive composition> The method for producing the thermally conductive composition of the present invention includes a step of preparing a mixture containing a curable compound, a thermally conductive filler, and a structure viscosity-imparting agent, a step of heating the mixture, and a step of cooling the mixture. The step of cooling the mixture is a step of adjusting the viscosity ratio (η1 / η3) of the viscosity η1 of the mixture measured by a rheometer under the conditions of a measurement temperature of 25°C and a shear rate of 0.0001 (1 / s) and the viscosity η3 of the mixture measured under the conditions of a measurement temperature of 25°C and a shear rate of 0.0251 (1 / s) to 60 or more by cooling the mixture. That is, the method for producing the thermally conductive composition of the present invention includes a step of mixing a curable compound, a thermally conductive filler, a structure viscosity-imparting agent, and additives optionally blended to prepare a mixture, a step of heating the mixture, and a step of cooling the mixture in this order. By going through such steps, the thermally conductive composition of the present invention in which the viscosity ratio (η1 / η3) is adjusted as described above can be obtained.

[0073] In addition, the method for producing the form of supply of the thermally conductive composition may include a step of filling the mixture into a container after the step of preparing a mixture containing a curable compound, a thermally conductive filler, and a structure viscosity-imparting agent in the above-mentioned method for producing the thermally conductive composition. The step of heating the mixture and the step of cooling the mixture are preferably performed after filling the mixture into the container.

[0074] The step of preparing the mixture may appropriately adopt a known mixing method. For example, it may be mixed using a known kneader, kneading roll, mixer, etc. The heating temperature in the step of heating the mixture may be equal to or higher than the temperature at which the structure viscosity imparting agent melts. For example, it is a temperature equal to or higher than the melting point of the structure viscosity imparting agent, preferably a temperature 10°C or higher than the melting point of the structure viscosity imparting agent and 50°C or lower than the melting point of the structure viscosity imparting agent. Also, the upper limit of the heating temperature is not particularly limited, but from the viewpoint of suppressing thermal deterioration of the structure viscosity imparting agent, it is preferably 200°C or lower, for example. When containing volatile components, it is preferably a low temperature within a possible range, for example, preferably 100°C or lower, and particularly preferably 80°C or lower. The heating time is not particularly limited, but is set to the time when the whole is heated according to the volume of the mixture. For example, it is 5 to 1000 minutes, preferably 10 to 500 minutes. When the heating time is equal to or longer than these lower limit values, it becomes easy to sufficiently heat the inside of the mixture. When the heating time is equal to or shorter than these upper limit values, when the mixture contains volatile substances, it is possible to suppress a part of the volatile substances from volatilizing. In the step of cooling the mixture, the mixture after the above heating is cooled. The cooling is carried out until the temperature of the mixture reaches 25°C. The cooling method is not particularly limited, and it may be a method of cooling using a cooler or a method of natural cooling, but it is preferable to cool quickly using a cooler.

[0075] <Two-component curable thermal conductive material> In the present invention, from the viewpoint of storage stability, etc., it is preferable to use a thermal conductive composition to form a two-component curable thermal conductive material. Specifically, a first agent composed of a thermal conductive composition containing an epoxy compound, a thermal conductive filler, and a structure viscosity imparting agent and having a viscosity ratio (η1 / η3) of 60 or more, and an epoxy curing agent, a thermal conductive filler, and a two-component curable thermal conductive material composed of a second agent composed of a thermal conductive composition containing a structure viscosity imparting agent and having a viscosity ratio (η1 / η3) of 60 or more is preferable. In addition, the heat-conductive compositions of the first agent and the second agent may contain the above-described sedimentation inhibitor, dispersant, polyfunctional acrylate compound, and other additives. When the polyfunctional acrylate compound is contained, it is preferably contained in the heat-conductive composition of the first agent described above. The mass ratio of the first agent to the second agent (second agent / first agent) is preferably 1 or a value close to 1. Specifically, 0.9 to 1.1 is preferable, and 0.95 to 1.05 is more preferable. By setting the mass ratio of the first agent to the second agent to 1 or a value close to 1 in this way, it becomes easy to prepare a mixture of the first agent and the second agent.

[0076] In the present invention, it is possible to provide a supply form of a two-component curable heat-conductive material that is a combination of a first container filled with a first agent composed of a heat-conductive composition containing an epoxy compound, a heat-conductive filler, and a structure viscosity-imparting agent, and a second container filled with a second agent composed of a heat-conductive composition containing an epoxy curing agent, a heat-conductive filler, and a structure viscosity-imparting agent. Further, the first container and the second container can be combined and integrated. By integrating the first container and the second container, it becomes easy to supply the container set to the customer. In this specification, the first container filled with the first agent and the second container filled with the second agent may sometimes be collectively referred to as a container set. The viscosity ratio (η1 / η3) of the first agent and the second agent, where η1 is the viscosity measured at a measurement temperature of 25°C and a shear rate of 0.0001 (1 / s) and η3 is the viscosity measured at a measurement temperature of 25°C and a shear rate of 0.0251 (1 / s) by a rheometer, is 60 or more.

[0077] As described above, the thermally conductive composition of the present invention is prepared through a process of preparing a mixture, a process of heating the mixture, and a process of cooling the mixture. Therefore, for example, a mixture (thermally conductive composition) containing an epoxy compound, a thermally conductive filler, and a structure viscosity-imparting agent is prepared, filled into a first container, and through the heating process and the cooling process, a first container filled with a first agent is obtained. Similarly, a mixture (thermally conductive composition) containing an epoxy curing agent, a thermally conductive filler, and a structure viscosity-imparting agent is prepared, filled into a second container, and through the heating process and the cooling process, a second container filled with a second agent is obtained. The first agent and the second agent filled in the first container and the second container respectively have suppressed sedimentation of the thermally conductive filler and are excellent in storage state. When in use, the first agent and the second agent can be discharged from the first container and the second container respectively, mixed by a static mixer or the like, and cured to form a thermally conductive member. When discharging the first agent and the second agent, a certain shear force is generated, so the viscosities of the first agent and the second agent are reduced and they can be easily discharged. Furthermore, the coating formed by the discharge is easy to compress and also excellent in handleability. For example, it becomes easy to perform operations such as discharging a mixture of the first agent and the second agent between a heating element and a heat sink to form a coating with a certain thickness and then thinly stretching the coating with a small load.

[0078] Examples of the containers in the first container and the second container include syringes, cartridges, pails, and drums. For example, when using a syringe as the container, it is a supply form of a two-component curing type thermally conductive material that is a combination of a first syringe filled with a first agent and a second syringe filled with a second agent. In this case, it is preferable to arrange and integrate the first syringe and the second syringe to form a two-component parallel type. As shown in FIG. 1, the two-component parallel type syringe 30 is formed by arranging and integrating a first syringe 31 constituting the first container and a second syringe 32 constituting the second container in parallel. The first agent 35 and the second agent 36 filled in the syringes 31 and 32 may be discharged from the syringes using the syringes as dispensers and then mixed.

[0079] Also, when using cartridges, it becomes a supply form of a two-component curable thermally conductive material that is a combination of a first cartridge filled with a first agent and a second cartridge filled with a second agent. Also in this case, the first cartridge and the second cartridge may be arranged in parallel and integrated to form a two-component parallel type.

[0080] The mixing of the first agent and the second agent is preferably performed with a mixer such as a static mixer. The static mixer 38 is connected to the discharge port 31A of the first syringe 31 and the discharge port 32A of the second syringe 32 as shown in FIG. 1, for example, and the first agent 35 and the second agent 36 discharged from the respective discharge ports 31A, 32A can be mixed inside the mixer 38. The mixture obtained by mixing with the mixer 38 is preferably discharged from the discharge port 39 of the mixer 38. Each of the syringes 31, 32 preferably has a structure in which the openings of the barrels 33A, 34A filled with the first agent 35 and the second agent 36 are closed by lid bodies 33B, 34B. In the syringe 30 shown in FIG. 1, the first agent 35 and the second agent 36 are preferably pushed out by a piston (not shown) inserted through the openings after the respective lid bodies 33B, 34B are removed, and are discharged from the respective discharge ports 31A, 32A.

[0081] Also, when using pails, the container set preferably includes a first pail 41 that constitutes a first container and is filled with a first agent 45 inside, and a second pail 42 that constitutes a second container and is filled with a second agent 46 inside, as shown in FIG. 2. Each of the pails 41, 42 includes, for example, container bodies 43A, 44A that are filled with the first agent 45 and the second agent 46 inside and have openings, and lid bodies 43B, 44B that close the openings of the respective container bodies 43A, 44A.

[0082] <Thermally conductive member> The present invention can also provide a thermally conductive member. The thermally conductive member is a cured product of the above-described thermally conductive composition, or a cured product of a two-component curable thermally conductive material obtained by mixing and curing the above-described first agent and second agent. By using a structure viscosity-imparting agent, the heat-conductive member of the present invention has excellent handleability of the heat-conductive composition as a raw material, so that the workability during the formation of the heat-conductive member is good. Further, in the heat-conductive composition as a raw material, sedimentation of the heat-conductive filler during storage is suppressed, and the composition is uniform. Therefore, the composition of the formed heat-conductive member is also uniform, and variations in physical properties are reduced.

[0083] The thermal conductivity of the heat-conductive member is preferably 1.0 W / m·K or more, more preferably 1.5 W / m·K or more, and even more preferably 2.0 W / m·K or more. By setting these values to be equal to or higher than the lower limit values, good thermal conductivity is achieved. Therefore, for example, when used as a gap material between battery cells in a battery cell module, heat generated from the battery cells can be efficiently transmitted to the module housing via the gap material, and excessive temperature rise of the battery cells can be suppressed. The thermal conductivity of the heat-conductive member is preferably as high as possible, but practically, it is, for example, 15 W / m·K or less. The thermal conductivity is measured in accordance with ASTM D5470.

[0084] [Applications] The heat-conductive composition, two-component curable heat-conductive material, supply form of the two-component curable heat-conductive material, and heat-conductive member formed therefrom of the present invention can be used in various applications. These can be used, for example, in various electronic device applications such as battery assemblies such as lithium-ion battery (LiB) assemblies, power electronic devices, electronic packaging, LEDs, solar cells, and electrical grids. Among these, it is preferably used in a battery assembly, and more preferably used in a LiB assembly. Therefore, in a preferred embodiment of the present invention, a battery assembly including the above-described heat-conductive member is provided. Note that battery assemblies such as LiB assemblies can be preferably used for automobiles.

[0085] In the application of the battery assembly, the thermally conductive composition, two-component curable thermally conductive material, supply form of the two-component curable thermally conductive material, and thermally conductive member formed therefrom of the present invention are preferably used as a spacer for the battery assembly. Further, the thermally conductive composition and the thermally conductive member of the present invention are preferably used in a battery module in one aspect, and more preferably used as a spacer for the battery module. Hereinafter, an example in which the thermally conductive member of the present invention is applied to a battery module will be described.

[0086] The thermally conductive member of the present invention can be used as a spacer in a battery module as follows. The battery module according to the present invention includes a spacer made of a thermally conductive member, a plurality of battery cells, and a module housing that houses the plurality of battery cells, and the spacer is disposed inside the module housing. The spacer made of a thermally conductive member is filled between the battery cells and between the battery cell and the module housing, and the filled spacer is in close contact with the battery cell and the module housing. Thereby, the spacer between the battery cells has a function of maintaining the separated state between the battery cells. Further, the spacer between the battery cell and the module housing is in close contact with both the battery cell and the module housing and has a function of transmitting heat generated in the battery cell to the module housing.

[0087] FIG. 3 shows a specific configuration of the battery module. FIG. 4 shows a specific configuration of each battery cell. As shown in FIG. 3, a plurality of battery cells 11 are arranged inside the battery module 10. Each battery cell 11 is encapsulated by laminating it in a flexible exterior film, and the overall shape is a flat body having a thickness thinner than the height and width. As shown in FIG. 4, in such a battery cell 11, the positive electrode 11a and the negative electrode 11b appear on the outside, and the central portion 11c of the flat surface is formed thicker than the crimped end portion 11d.

[0088] As shown in FIG. 3, each battery cell 11 is arranged such that its flat surfaces face each other. In the configuration of FIG. 3, the gap filler 13 is not filled so as to cover the entire plurality of battery cells 11 stored inside the module housing 12. The gap filler 13 is filled so as to fill a gap existing in a part (bottom side part) inside the module housing 12. The gap filler 13 is filled between the battery cells 11 and between the battery cells 11 and the module housing 12, and is in close contact with the surface of the battery cells 11 in this part and the inner surface of the module housing 12.

[0089] The gap filler 13 filled between the battery cells 11 is adhered to the surfaces of both battery cells 11. However, the gap filler 13 itself has appropriate elasticity and flexibility, and even when an external force that displaces the distance between the battery cells 11 is applied, it can relieve the strain deformation caused by the external force. Therefore, the gap filler 13 has a function of maintaining the separated state between the battery cells 11. The gap filler 13 filled in the gap between the battery cell 11 and the inner surface of the module housing 12 is also closely adhered to the surface of the battery cell 11 and the inner surface of the module housing 12. As a result, the heat generated inside the battery cell 11 is transmitted to the inner surface of the module housing 12 that is in close contact with the other surface of the gap filler 13 via the gap filler 13 adhered to the surface of the battery cell 11.

[0090] The formation of the gap filler 13 in the battery module 10 may be performed by applying a liquid thermally conductive composition or a two-component curable thermally conductive material using a general dispenser and then curing the coating. In the case of a two-component curable thermally conductive material, for example, the above-described first container and second container may be set in the dispenser and applied by the dispenser. The two-component curable thermally conductive material is easy to store, is difficult to cure during the application work with the dispenser if mixed immediately before use, and can be cured rapidly after application. Further, the application with the dispenser is also preferable in that it can be filled relatively deeply inside the housing 12 of the battery module 10.

[0091] The spacer 13 covering the battery cell 11 preferably covers 20 to 100% of each battery cell 11 on one side of the battery cell 11, and more preferably covers 20 to 40%. By setting it to 20% or more, the battery cell 11 can be stably held. Also, by sufficiently covering the battery cell with a large calorific value, the heat dissipation efficiency becomes good. On the other hand, by setting it to 100% or less, the heat generated from the battery cell 11 can be efficiently dissipated. Also, by setting it to 40% or less, an increase in weight and deterioration of workability can be prevented. Further, in order to improve the heat dissipation efficiency, it is preferable to cover the side where the electrodes 11a and 11b of the battery cell 11 are located with the spacer 13, and it is more preferable to cover the entire electrodes 11a and 11b with the spacer 13.

[0092] As described above, the battery module 10 can release the heat generated from the battery cell 11 to the module housing 12 via the spacer 13. It is also preferable to use the spacer 13 for a battery pack that includes a plurality of battery modules 10 therein. Generally, a battery pack includes a plurality of battery modules 10 and a housing of the battery pack that houses the plurality of battery modules 10. In the battery pack, a spacer 13 can be provided between the battery module 10 and the battery pack housing. Thereby, the heat released to the module housing 12 as described above can be further released to the housing of the battery pack, enabling effective heat dissipation. Also, since the heat conductive member of the present invention is used for the spacer 13, the workability when forming the spacer 13 is excellent.

[0093] Also, in the above description, an example in which the battery assembly is a battery module or a battery pack including a battery module has been described, but it may be applied to a battery assembly that does not have a battery module, and for example, it is also preferably applied to a battery assembly having a cell-to-pack structure.

[0094] A schematic diagram of a battery assembly having a cell-to-pack structure is shown in FIG. 5. A battery assembly 20 having a cell-to-pack structure includes a plurality of battery cells 21 and a housing of the battery pack. The plurality of battery cells 21 are adhered to a base member 25 constituting the housing of the battery pack via a spacer 23 made of a heat-conductive member (a cured product of a heat-conductive composition). The base member 25 may constitute a cooling plate or the like. Note that the formation of the spacer 23 in the battery assembly 20 may be performed in the same manner as the formation of the spacer 13 in the battery module, for example, using a general dispenser. The heat-conductive composition of the present invention also has good workability when forming the spacer 23. Further, since the heat-conductive composition of the present invention is also excellent in compressibility, the battery cells 21 can be adhered to the base member 25 with high workability even in a battery assembly having a cell-to-pack structure.

Example

[0095] Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0096] The measurement method and evaluation method in this example are as follows.

[0097] [Viscosity] For Examples 1 to 6 and Comparative Examples 1 to 2, the viscosities of the first agent and the second agent, which are heat-conductive compositions, were measured as follows. The viscosities of the first agent and the second agent were measured at various shear rates using a rheometer with each as a sample. Using a rheometer MCR-302e manufactured by Anton Paar, the temperature of the sample was adjusted to 85 °C, which is above the melting point of each structurant, with a Peltier plate and allowed to stand for 5 minutes. Then, it was cooled to 25 °C at a cooling rate of 20 °C / min and left standing for 10 minutes. Thereafter, using a φ25 mm parallel plate, viscosity measurement was performed while continuously changing the shear rate. And the viscosity η1 measured under the condition of a shear rate of 0.0001 (1 / s), the viscosity η3 measured under the condition of a shear rate of 0.0251 (1 / s), and the viscosity η2 measured under the condition of a shear rate of 25.1 (1 / s) were measured respectively, and the viscosity ratio (η1 / η3) was determined. The viscosities at shear rates other than the above were also measured as shown in Table 1.

[0098] [Melting Point of Ester Compound in Thermally Conductive Composition] For Examples 1 to 6, the melting points of the structurants in the thermally conductive composition were measured by the following method. Specifically, after weighing 20 mg of the first agent or the second agent, which is a thermally conductive composition, in an aluminum cell, using a DSC-60 manufactured by Shimadzu Corporation, the temperature was raised from 25 °C to 90 °C at a rate of 10 °C / min under a nitrogen flow.

[0099] [Thermal Conductivity] The thermal conductivities of the first agent and the second agent, which are thermally conductive compositions, were determined by a method of measuring the thermal resistance using a measuring device conforming to ASTM D5470-06. Specifically, the thermally conductive composition was placed in an amount more than the thickness at the time of measurement so as to cover the measurement die on the heating element side, and then sandwiched between heat sinks, and compressed with a load of 30 psi until the thickness of the thermally conductive composition became 1.0 mm, 1.5 mm, and 2.0 mm, and the thermal resistance at each thickness was measured. The thickness can be adjusted with a spacer. For these three thermal resistance values, a graph with the thickness on the horizontal axis and the thermal resistance value on the vertical axis was created, and an approximate straight line of the three points was obtained by the least squares method. And the slope of the approximate straight line is the thermal conductivity. The measurement of thermal resistance was carried out at 80 °C using an LW-9389 manufactured by Long Win Science and Technology Corporation. The area of the measurement die was set to 1 inch × 1 inch.

[0100] [Sedimentation Inhibition Evaluation] For Examples 1 to 6 and Comparative Examples 1 to 2, the sedimentation inhibition evaluation was carried out as follows. For each of the First Agent and the Second Agent, the sedimentation inhibition evaluation was carried out as follows. 10 cc of each sample was placed in a 15 cc transparent container (cylindrical shape with a diameter of 24 mm), and each was heated at the melting point of the structure viscosity imparting agent + 10 °C for 30 minutes. Subsequently, it was naturally cooled until the temperature of the sample reached 25 °C in a 25 °C atmosphere and left standing for 1 day, and then the state of the sample after being left in a 35 °C environment for 30 days was confirmed. For each of the First Agent and the Second Agent of each Example and Comparative Example, evaluation was carried out according to the following criteria and designated as "Sedimentation Inhibition Evaluation". Also, among the "Sedimentation Inhibition Evaluations" of the First Agent and the Second Agent, the one with the worse evaluation was designated as "Sedimentation Inhibition Evaluation (Overall)". (Evaluation Criteria) 5 There was no visible change. 4 The liquid component slightly oozed out to the edge of the surface. 3 The liquid component slightly oozed out to the surface, but the liquid component did not flow even when tilted. 2 The liquid component slightly oozed out to the surface, and the liquid component flowed when tilted. 1 The liquid component was separated when viewed from the side.

[0101] [Compressibility Evaluation (Compressibility)] For Examples 1 to 6 and Comparative Examples 1 to 2, the compressibility evaluation was carried out as follows. 16.4 cc each of the raw material of the First Agent and the raw material of the Second Agent described in the table was introduced into a first syringe and a second syringe, which were 25 cc syringes of the two-liquid parallel type. Subsequently, the First Agent and the Second Agent were heated to the melting point of each structure viscosity imparting agent + 10 °C, and after 15 minutes had elapsed, they were cooled to 25 °C and left standing for 10 minutes. Subsequently, a 2.5 cc sample (a mixture of the first agent and the second agent (mass ratio 1:1)) in the shape of an aluminum plate was discharged using a static mixer. Subsequently, the discharged material was compressed at a compression speed of 60 mm / min with a pusher (a jig for compression test) of 30 mm Φ, and the load value when the gap between the jigs was compressed to 0.380 mm was read, and this was taken as the compression load. The temperature when conducting the compression test was set at 25°C. Based on the value of the compression load, the compressibility was evaluated according to the following criteria. (Evaluation Criteria) Less than 5,250 N 4,250 N or more and less than 300 N 3,300 N or more and less than 350 N 2,350 N or more and less than 400 N 1,400 N or more

[0102] [Comprehensive Evaluation] For each example and comparative example, the average value of the sedimentation inhibition evaluation and the compressibility evaluation was taken as the comprehensive evaluation. Specifically, the value of the comprehensive evaluation was calculated based on the following formula. Comprehensive Evaluation = (Sedimentation Inhibition Evaluation (Comprehensive) + Compressibility Evaluation) / 2

[0103] In each example and comparative example, the following respective components were used. <Epoxy Compound> · Polyfunctional epoxy compound: Bisphenol F type epoxy resin, manufactured by Mitsubishi Chemical Corporation, trade name "jER806", molecular weight 330, epoxy equivalent 165 g / eq, number of functional groups 2, viscosity (25°C) 400 mPa·s · Monofunctional epoxy compound: Aliphatic glycidyl ether (aliphatic alcohol is C12 - 14), trade name "Epogose ML", manufactured by Yokkaichi Gosei Co., Ltd., epoxy equivalent 282 g / eq, number of functional groups 1, viscosity (25°C) 7 mPa·s

[0104] <Epoxy Curing Agent> · Amine compound: Trimethylolpropane poly(oxypropylene) triamine, manufactured by Huntsman (trade name "T-403"), molecular weight 440, active hydrogen equivalent 73.3 g / eq, number of active hydrogens of amino group = 6, functional group = 3×(-NH2), viscosity (25°C) 0.07 Pa·s

[0105] <Polyfunctional acrylate compound> · Polyfunctional acrylate compound: Dipentaerythritol hexaacrylate, manufactured by Daicel Ornex Co., Ltd. "DPHA"

[0106] <Dispersant> Polymeric dispersant (acid group-containing copolymer)

[0107] <Structure viscosity-imparting agent (ester compound X that is solid at 25°C)> · Stearyl stearate Melting point 57°C, carbon number 36 · Behenyl behenate Melting point 75°C, carbon number 44 The above melting point was measured by weighing 20 mg of the structure viscosity-imparting agent in an aluminum cell and then heating from 25°C to 90°C at a rate of 10°C / min under nitrogen flow using DSC-60 of Shimadzu Corporation.

[0108] <Sedimentation inhibitor> · Amide wax: Fatty acid amide wax (melting point 122°C) · Fumed silica: Nippon Aerosil Co., Ltd. "AEROSIL 300", hydrophilic, specific surface area 300 m 2 / g

[0109] <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 90 μm Aluminum oxide (alumina): Average particle size 45 μm

[0110] [Examples 1 to 6, Comparative Examples 1 to 2] The first agent and the second agent were prepared with the formulations shown in Tables 1 to 3, and the above-mentioned viscosity, sedimentation inhibition evaluation, and compressibility evaluation were performed. The results are shown in Tables 1 to 3.

[0111]

Table 1

[0112]

Table 2

[0113]

Table 3

[0114] Each of the thermal conductive compositions of Examples 1 to 6 contains a curable compound, a thermal conductive filler, and a structure viscosity-imparting agent, and is a composition having a viscosity ratio (η1 / η3) of 60 or more, satisfying the requirements of the present invention. In each example, since the result of the sedimentation inhibition evaluation was good, sedimentation of the thermal conductive filler was suppressed during storage. Also, the compressibility evaluation was good, and it was found that the handleability was excellent. On the other hand, the thermal conductive composition of Comparative Example 1 did not contain a structure viscosity-imparting agent and had a viscosity ratio (η1 / η3) of less than 60. Therefore, in Comparative Example 1, the result of the sedimentation inhibition evaluation was poor and the storage stability was inferior. The thermal conductive composition of Comparative Example 2 is an example in which fumed silica is blended instead of the structure viscosity-imparting agent. Although the sedimentation inhibition evaluation was slightly worse than that of the examples, the compressibility evaluation was much inferior to that of the examples, and it was found that the handleability was inferior.

Explanation of Symbols

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

Claims

1. The composition includes at least one curable compound selected from the group consisting of an epoxy compound and an epoxy curing agent, a thermally conductive filler, and a structural viscosity imparting agent; The thermally conductive filler is at least one selected from the group consisting of metals, metal oxides, metal nitrides, metal hydroxides, carbon materials, oxides, nitrides, and carbides of materials other than metals; The content of the thermally conductive filler is 150 to 3000 parts by mass relative to 100 parts by mass of the curable compound, The structural viscosity imparting agent is a compound having a melting point of more than 25° C. and not more than 120° C., The content of the structural viscosity imparting agent is 0.5 to 20 parts by mass relative to 100 parts by mass of the curable compound, A thermally conductive composition, in which the viscosity ratio (η1 / η3) between a viscosity η1 measured with a rheometer at a measurement temperature of 25°C and a shear rate of 0.0001 (1 / s) and a viscosity η3 measured at a measurement temperature of 25°C and a shear rate of 0.0251 (1 / s) is 60 or more.

2. 2. The thermally conductive composition according to claim 1, having a viscosity η2 measured at a measurement temperature of 25° C. and a shear rate of 25.1 (1 / s) of 125 Pa·s or less.

3. The thermally conductive composition according to claim 1 or 2, wherein the structural viscosity imparting agent is an ester compound having a melting point of more than 25°C and not more than 120°C.

4. The thermally conductive composition according to claim 3 , wherein the ester compound has 20 or more and 50 or less carbon atoms.

5. 4. The thermally conductive composition according to claim 3, wherein the ester compound is at least one selected from the group consisting of cetyl myristate, pentaerythritol distearate, myristyl myristate, myristyl stearate, stearyl stearate, behenyl behenate, glycerin monostearyl ester, and ethylene glycol distearyl ester.

6. The thermally conductive composition of claim 1 , wherein the curable compound is an epoxy compound.

7. The thermally conductive composition of claim 1 , wherein the curable compound is an epoxy curing agent.

8. The thermally conductive composition of claim 7 , wherein the epoxy curing agent is an amine compound.

9. A two-component curing thermally conductive material comprising a first part comprising the thermally conductive composition according to claim 6 and a second part comprising the thermally conductive composition according to claim 7.

10. a first container filled with a first agent made of a thermally conductive composition including an epoxy compound, a thermally conductive filler, and a structural viscosity imparting agent; and a second container filled with a second agent comprising a thermally conductive composition including an epoxy curing agent, a thermally conductive filler, and a structural viscosity imparting agent; the thermally conductive filler contained in the first agent and the second agent is at least one selected from the group consisting of metals, metal oxides, metal nitrides, metal hydroxides, carbon materials, oxides, nitrides, and carbides of materials other than metals; The content of the thermally conductive filler contained in the first agent is 150 to 3000 parts by mass relative to 100 parts by mass of the epoxy compound, The content of the thermally conductive filler contained in the second agent is 150 to 3000 parts by mass relative to 100 parts by mass of the epoxy curing agent, The structural viscosity imparting agent contained in the first agent and the second agent is a compound having a melting point of more than 25° C. and not more than 120° C., The content of the structural viscosity imparting agent contained in the first agent is 0.5 to 20 parts by mass relative to 100 parts by mass of the epoxy compound, The content of the structural viscosity imparting agent contained in the second agent is 0.5 to 20 parts by mass relative to 100 parts by mass of the epoxy curing agent, A supply form of a two-component curing thermally conductive material, in which each of the first and second parts has a viscosity ratio (η1 / η3) of 60 or more between a viscosity η1 measured by a rheometer at a measurement temperature of 25°C and a shear rate of 0.0001 (1 / s) and a viscosity η3 measured at a measurement temperature of 25°C and a shear rate of 0.0251 (1 / s).

11. The supply form of the two-component curing thermally conductive material according to claim 10, wherein the structural viscosity imparting agent contained in the first part and the second part is an ester compound having a melting point of more than 25°C and not more than 120°C.

12. The supply form of the two-component curing thermally conductive material according to claim 11 , wherein the ester compound has a carbon number of 20 or more and 50 or less.

13. 12. The supply form of the two-component curing thermally conductive material according to claim 11, wherein the ester compound is one or more selected from the group consisting of cetyl myristate, pentaerythritol distearate, myristyl myristate, myristyl stearate, stearyl stearate, behenyl behenate, glycerin monostearyl ester, and ethylene glycol distearyl ester.

14. A thermally conductive member which is a cured product of the thermally conductive composition according to claim 1 or 2.

15. A thermally conductive member which is a cured product of the two-component curing type thermally conductive material according to claim 9.

16. A battery module comprising: a gap material made of the thermally conductive member according to claim 14; a plurality of battery cells; and a module housing that houses the plurality of battery cells, the gap material being disposed inside the module housing.

17. Preparing a mixture comprising at least one curable compound selected from the group consisting of epoxy compounds and epoxy curing agents, a thermally conductive filler, and a structural viscosity imparting agent; heating the mixture; a step of adjusting a viscosity ratio (η1 / η3) of the mixture measured by a rheometer under conditions of a measurement temperature of 25° C. and a shear rate of 0.0001 (1 / s) to a viscosity ratio (η1 / η3) of the mixture measured under conditions of a measurement temperature of 25° C. and a shear rate of 0.0251 (1 / s) to be 60 or more by cooling the mixture; 2. The method for producing the thermally conductive composition according to claim 1, further comprising the steps of:

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