Thermally conductive rubber composition

Abstract

A thermally conductive rubber composition includes a base rubber, a thermally conductive filler, and an aliphatic amine compound. The thermally conductive rubber composition has a Shore hardness (type A) of 80 or less, a thermal conductivity of 3.0 W / mK or more, and an elongation at break of 300% or more.

Description

Technical Field

[0001] This disclosure relates to thermally conductive rubber compositions. Background Technology

[0002] In recent years, with the continuous miniaturization and performance improvement of electronic devices and other equipment, the heat load they experience has been increasing. In order to reduce this heat load, it is necessary to attach heat dissipation components with high thermal conductivity to the equipment to effectively dissipate heat from the equipment.

[0003] If an air gap forms between the equipment and the heat dissipation component, the heat transfer efficiency between them will decrease. Therefore, a highly flexible heat-dissipating rubber that can tightly conform to the equipment is used to form the heat dissipation component. This heat-dissipating rubber is made of a thermally conductive rubber composition containing a large amount of highly thermally conductive filler. Generally, the more filler contained in the rubber, the more difficult it is for the filler to disperse in the rubber, and the less flexible the heat-dissipating rubber may be.

[0004] Patent documents 1 to 3 disclose the use of silane coupling agents to treat the surface of fillers in order to improve the dispersibility of fillers in rubber.

[0005] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2012-211250 Patent Document 2: Japanese Patent Application Publication No. 2013-83699 Patent Document 3: Japanese Patent Application Publication No. 2021-176931 Summary of the Invention The problem the invention aims to solve However, there is still room for improvement in thermally conductive rubber compositions containing coupling agents, such as those disclosed in Patent Documents 1 to 3, in achieving both high thermal conductivity and low hardness.

[0006] In view of the above, the purpose of this disclosure is to provide a thermally conductive rubber composition with excellent heat dissipation properties.

[0007] means for solving problems According to one aspect of this disclosure, the thermally conductive rubber composition comprises a matrix rubber, a thermally conductive filler, and an aliphatic amine compound. The thermally conductive rubber composition has a Shore hardness of 80 or lower (Type A), a thermal conductivity of 3.0 W / mK or higher, and an elongation at break of 300% or greater.

[0008] The effects of the invention This disclosure provides a thermally conductive rubber composition with excellent heat dissipation properties. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of a thermally conductive rubber composition according to an embodiment.

[0010] Figure 2 The role of aliphatic amine compounds in a thermally conductive rubber composition according to an embodiment is shown.

[0011] Figure 3 A table illustrating the properties of the thermally conductive rubber compositions of Examples 1 to 10 and Comparative Examples 1 to 3. Detailed Implementation

[0012] Preferred embodiments of the present disclosure will now be described with reference to the accompanying drawings. In the drawings, the dimensions and proportions of the components may vary appropriately from actual dimensions and proportions, and some components are shown schematically for ease of understanding. Unless explicitly stated in the following description, the scope of this disclosure is not limited to these embodiments.

[0013] 1. Implementation Method Figure 1 This is a schematic diagram of the thermally conductive rubber composition 10 according to an embodiment. The thermally conductive rubber composition 10 can be molded into a sheet and used as a heat sink for bonding to an electronic substrate of an electronic device or other device. The use of the thermally conductive rubber composition 10 is not limited to heat dissipation of an electronic substrate, and its use can be appropriately selected as needed.

[0014] The thermally conductive rubber composition 10 has: a Shore hardness of 80 or lower (Type A); a thermal conductivity of 3.0 W / mK or higher; and an elongation at break of 300% or higher. These properties provide the thermally conductive rubber composition 10 with high thermal conductivity and improved fit to the object to which heat is dissipated. Therefore, the thermally conductive rubber composition exhibits excellent heat dissipation. The Shore hardness (Type A) of the thermally conductive rubber composition is 80 or lower. However, the Shore hardness (Type A) of the thermally conductive rubber composition is preferably 40 or higher. The thermally conductive rubber composition 10 is flexible.

[0015] Shore hardness (Type A) can be measured using a Type A Shore hardness tester according to JIS K 6253-3:2012. Thermal conductivity can be measured according to ASTM D7984. Elongation at break can be measured according to JIS K 6251.

[0016] like Figure 1 As shown, the thermally conductive rubber composition 10 includes a rubber portion 11 and a thermally conductive filler 12.

[0017] Rubber portion 11 comprises a base rubber and an aliphatic amine compound. Thermally conductive rubber composition 10 comprises a base rubber, a thermally conductive filler 12, and an aliphatic amine compound. In addition to the base rubber and the aliphatic amine compound, rubber portion 11 may contain additives. Examples of additives include crosslinking agents, photocuring agents, conductivity-imparting agents, flame retardants, softeners, anti-aging agents, UV absorbers, and colorants.

[0018] 1-1. Matrix rubber The base rubber is not particularly limited, but preferably includes at least one rubber selected from the group consisting of ethylene-propylene-diene rubber, silicone rubber, acrylic rubber, nitrile rubber, and fluororubber. More preferably, the base rubber includes ethylene-propylene-diene rubber or silicone rubber. Such a base rubber can improve the thermal conductivity of the thermally conductive rubber composition 10 and reduce its hardness. The base rubber is obtained by crosslinking the raw material polymer with a crosslinking agent.

[0019] 1-2. Aliphatic amine compounds Aliphatic amines are compounds in which an amino group is bonded to a hydrocarbon that does not contain an aromatic ring. See below for reference. Figure 2 As described in detail, these aliphatic amine compounds are readily compatible with the matrix rubber and readily physical adsorbed onto the thermally conductive filler 12, thereby providing improved dispersibility of the thermally conductive filler in the matrix rubber. The improved dispersibility of the thermally conductive rubber composition results in low hardness even when the thermal conductivity of the thermally conductive rubber composition 10 increases. Furthermore, the aliphatic amine compounds are less likely to undergo self-reactions, such as reactions between silane coupling agents. Compared to aspects using silane coupling agents, the thermally conductive rubber composition exhibits lower hardness and higher elongation at break.

[0020] Even when the thermal conductivity of the thermally conductive rubber composition 10 is increased, the thermally conductive rubber composition 10 still has improved flexibility and excellent heat dissipation.

[0021] The aliphatic amine compound included in the thermally conductive rubber composition 10 preferably has an amine equivalent of 135 or lower, more preferably 78 or higher and 135 or lower. When the aliphatic amine compound has an amine equivalent within this range, the dispersibility of the thermally conductive filler 12 in the matrix rubber is improved. The improved dispersibility reduces the hardness of the thermally conductive rubber composition 10. The amine equivalent is a value obtained by dividing the molecular weight of the amine by the number of active hydrogen atoms in the amine, i.e., (molecular weight of the amine) / (number of active hydrogen atoms in the amine).

[0022] More specifically, examples of aliphatic amine compounds include those composed of CH3(CH2). nCompounds represented by NH2 (where n is a natural number of 10 or greater and 20 or less), triethylenetetramine represented by [CH2NHCH2CH2NH2]2, and compounds represented by NH2(CH2) n Compounds represented by NH2 (where n is a natural number of 6 or greater and 8 or less). These compounds can be used alone, or in combination of two or more. The use of these aliphatic amine compounds improves the dispersibility of thermally conductive filler 12 in the matrix rubber.

[0023] From CH3(CH2) n Examples of aliphatic amine compounds represented by NH2 (where n is a natural number of 10 or greater and 20 or less) include 1-aminodecane, 1-aminotridecane, hexadecylamine (1-aminohexadecane), and stearylamine (1-aminooctadecane). One of these compounds may be used alone, or two or more of these compounds may be used in combination.

[0024] From NH2(CH2) n Examples of aliphatic amine compounds represented by NH2 (where n is a natural number of 6 or greater and 8 or less) include 1,6-diaminohexane and 1,8-diaminooctane. These compounds can be used alone, or in combination of two or more.

[0025] The amount of aliphatic amine compound contained in the thermally conductive rubber composition 10 is preferably 5 parts by mass or more and 30 parts by mass or less, relative to 100 parts by mass of the base rubber. More preferably, the amount of aliphatic amine compound is 10 parts by mass or more and 30 parts by mass or less, and even more preferably 10 parts by mass or more and 20 parts by mass or less, relative to 100 parts by mass of the base rubber. Such amounts maintain the properties of the base rubber and improve the dispersibility of the thermally conductive filler 12 in the base rubber.

[0026] If the amount of aliphatic amine compound contained in the thermally conductive rubber composition 10 is too small, the dispersibility of the thermally conductive filler 12 in the matrix rubber tends to decrease, depending on the type of aliphatic amine compound or thermally conductive filler used. Conversely, if the amount of aliphatic amine compound in the thermally conductive rubber composition 10 is too large, the tensile strength of the thermally conductive rubber composition 10 tends to decrease, depending on the type of matrix rubber used.

[0027] 1-3. Thermally conductive fillers The thermally conductive filler 12 is a powder with a thermal conductivity higher than that of the base rubber. In the thermally conductive rubber composition 10, the thermally conductive filler 12 has the function of transferring heat H more effectively than the base rubber. The thermally conductive filler 12 improves the thermal conductivity of the thermally conductive rubber composition 10.

[0028] The thermally conductive filler 12 is preferably an insulating inorganic filler. Specifically, the thermally conductive filler 12 preferably includes at least one filler selected from the group consisting of metal oxide fillers, metal nitride fillers, and metal oxynitride fillers. Such a thermally conductive filler 12 improves the overall insulation of the thermally conductive rubber composition 10 and increases the thermal conductivity of the thermally conductive rubber composition 10. The thermally conductive filler 12 can be obtained by making the surface of the metal filler insulating through oxidation treatment or another treatment.

[0029] Specifically, the thermally conductive filler 12 preferably comprises zinc oxide filler. Zinc oxide filler readily contains hydroxyl groups on its surface without any separate treatment. When the thermally conductive filler 12 comprises zinc oxide filler, the effects of the aliphatic amine compounds described later are achieved. This achieves the thermal conductivity of the thermally conductive rubber composition 10. Hydroxyl groups can also be present on the surface of the thermally conductive filler 12 by separately treating the surface (such as plasma treatment).

[0030] The thermally conductive filler 12 preferably has an average particle size of 30 μm or larger and 70 μm or smaller, more preferably 40 μm or larger and 60 μm or smaller. Such an average particle size reduces the total contact area between the particles of the thermally conductive filler 12 and facilitates a high-density arrangement of the thermally conductive filler 12 in the thermally conductive rubber composition 10. This advantage contributes to achieving an increase in the thermal conductivity and a decrease in the hardness of the thermally conductive rubber composition 10.

[0031] Specifically, in view of reducing the total contact area between the particles of the thermally conductive filler 12 and the thermally conductive filler 12 being arranged in a high density in the thermally conductive rubber composition 10, the thermally conductive filler 12 preferably includes a variety of fillers, each of which has a different average particle size.

[0032] Here, the thermally conductive filler 12 includes a first filler and a second filler, wherein the average particle size of the second filler is smaller than the average particle size of the first filler. The content of the first filler is greater than the content of the second filler. This configuration increases the average particle size of the thermally conductive filler 12 and increases its filling rate. Specifically, the first filler reduces the total contact area between the particles of the thermally conductive filler 12, while the second filler causes the thermally conductive filler 12 to be arranged in a high-density manner in the thermally conductive rubber composition 10. Thus, the thermally conductive rubber composition 10 achieves both increased thermal conductivity and reduced hardness.

[0033] The first filler preferably has an average particle size in the range of 60 μm or larger and 80 μm or smaller. The second filler preferably has an average particle size in the range of 5 μm or larger and 20 μm or smaller. By setting the average particle sizes of the first filler and the second filler in these ranges, the total contact area between the particles of the thermally conductive filler 12 is reduced, and the thermally conductive filler 12 is arranged in a high density in the thermally conductive rubber composition 10.

[0034] In addition to the first and second fillers, the thermally conductive filler 12 may include a third filler, the average particle size of which is smaller than that of the second filler. In this case, considering both increasing the average particle size and the filling rate of the thermally conductive filler 12, the content of the third filler is preferably lower than that of the second filler. When the average particle sizes of the first and second fillers are within the aforementioned range, the third filler preferably has an average particle size in the range of 0.5 μm or larger and 2 μm or smaller. This configuration reduces the total contact area between the particles of the thermally conductive filler 12 and allows the thermally conductive filler 12 to be arranged in a high-density manner in the thermally conductive rubber composition 10.

[0035] The particle shape of the thermally conductive filler 12 is not particularly limited, but it is preferably spherical. The thermally conductive filler 12 preferably comprises spherical fillers. This configuration reduces the total contact area between the particles of the thermally conductive filler 12 and allows the thermally conductive filler 12 to be arranged in a high-density manner in the thermally conductive rubber composition 10. From this viewpoint, when the thermally conductive filler 12 comprises the first filler and the second filler described above, it is preferable that the first filler is a spherical filler, and more preferably that both the first filler and the second filler are spherical fillers.

[0036] The amount of thermally conductive filler 12 contained in the thermally conductive rubber composition 10 is preferably 1500 parts by weight or higher and 1800 parts by weight or lower relative to 100 parts by weight of the base rubber. The amount of thermally conductive filler 12 is preferably 1500 parts by weight or higher and 1700 parts by weight or lower relative to 100 parts by weight of the base rubber. Such amounts help to improve the thermal conductivity of the thermally conductive rubber composition 10 and reduce its hardness.

[0037] If the amount of thermally conductive filler 12 is too small, the thermally conductive rubber composition 10 will often struggle to achieve a thermal conductivity of 3.0 W / mK or higher, depending on the type of thermally conductive filler 12. If the amount of thermally conductive filler 12 is too large, the thermally conductive rubber composition 10 will often struggle to achieve a Shore hardness (Type A) of 80 or lower, depending on the shape of the thermally conductive filler 12 or the type of matrix rubber.

[0038] 1-4. The role of aliphatic amine compounds Figure 2The role of the aliphatic amine compound in the thermally conductive rubber composition 10 according to the embodiment is shown. Figure 2 It shows the composition of CH3(CH2). n The compounds represented by NH2 are used as aliphatic amine compounds.

[0039] like Figure 2 As shown, the surface of the thermally conductive filler 12 has hydroxyl groups (-OH). The amino groups (-NH2) of the aliphatic amine compound are physically adsorbed onto the hydroxyl groups on the surface of the thermally conductive filler 12 via hydrogen bonds. Because the aliphatic amine compound has a straight-chain alkyl chain with excellent lipophilicity, it is easily miscible with the matrix rubber.

[0040] When the aliphatic amine compound is kneaded together with the matrix rubber and the thermally conductive filler 12, the aliphatic amine compound is physically adsorbed onto the surface of the thermally conductive filler 12 during the kneading process. This physical adsorption of the aliphatic amine compound improves the dispersibility of the thermally conductive filler 12 in the thermally conductive rubber composition 10. The improved dispersibility reduces the hardness of the thermally conductive rubber composition 10 and increases its elongation at break. Therefore, the thermally conductive rubber composition 10 exhibits improved flexibility.

[0041] Even when using aliphatic amine compounds, the thermally conductive rubber composition 10 can still be manufactured using the same method as conventional rubber kneading. Unlike aspects using silane coupling agents, there is no need to change the temperature or time during the kneading process. The number of steps required to manufacture the thermally conductive rubber composition 10 does not increase, and the energy cost generated in manufacturing the thermally conductive rubber composition 10 is low.

[0042] 2. Example The following describes specific embodiments of the present invention. However, the present invention is not limited to these embodiments.

[0043] 2-1. Preparation of thermally conductive rubber compositions 2-1-1. Example 1 First, knead the following materials in a kneader at 70°C for 10 minutes to obtain a composite.

[0044] EPDM polymer (EPT4045, manufactured by Mitsui Chemicals, Inc.): 100 parts by weight (phr) Crosslinking agent (Percumyl D, manufactured by NOF): 3 parts by weight (phr) Thermally conductive filler (LPZINC-50S, manufactured by Sakai Chemical Industry Co., Ltd.): 1085 parts by weight (phr) Thermally conductive filler (LPZINC-11, manufactured by Sakai Chemical Industry Co., Ltd.): 310 parts by weight (phr) Thermally conductive filler (zinc oxide type 1, manufactured by Sakai Chemical Industry Co., Ltd.): 155 parts by weight (phr) Aliphatic amine compound (1-aminodecane, manufactured by Tokyo Chemical Industry Co., Ltd.): 10 parts by weight (phr) Thermally conductive packing (LPZINC-50S, manufactured by Sakai Chemical Industry Co., Ltd.) is a spherical packing made of zinc oxide with a particle size of 70 μm. Thermally conductive packing (LPZINC-11, manufactured by Sakai Chemical Industry Co., Ltd.) is a spherical packing made of zinc oxide with a particle size of 11 μm. Thermally conductive packing (Zinc Oxide Type 1, manufactured by Sakai Chemical Industry Co., Ltd.) is a spherical packing made of zinc oxide with a particle size of 0.75 μm.

[0045] 1-Aminodecane has a molecular weight of 157.3, two active hydrogens, and an amine equivalent of 78.8.

[0046] The resulting composite was rolled into a sheet, which was then molded at 200°C for 8 minutes. In this way, the thermally conductive rubber composition of Example 1 was obtained.

[0047] 2-1-2. Example 2 The thermally conductive rubber composition of Example 2 was obtained in the same manner as in Example 1, except that an aliphatic amine compound (1-aminotridecane, manufactured by Tokyo Chemical Industry Co., Ltd.) was used.

[0048] 1-Aminotridecane has a molecular weight of 199.38, two active hydrogens, and an amine equivalent of 99.7.

[0049] 2-1-3. Example 3 The thermally conductive rubber composition of Example 3 was obtained in the same manner as in Example 1, except that an aliphatic amine compound (hexadecylamine, manufactured by Tokyo Chemical Industry Co., Ltd.) was used.

[0050] Hexadecylamine has a molecular weight of 241.5, two active hydrogens, and an amine equivalent of 120.7.

[0051] 2-1-4. Example 4 The thermally conductive rubber composition of Example 4 was obtained in the same manner as in Example 1, except that an aliphatic amine compound (stearylamine, manufactured by Tokyo Chemical Industry Co., Ltd.) was used.

[0052] Stearylamine has a molecular weight of 269.5, two active hydrogens, and an amine equivalent of 134.8.

[0053] 2-1-5. Example 5 The thermally conductive rubber composition of Example 5 was obtained in the same manner as in Example 1, except that an aliphatic amine compound (triethylenetetramine, manufactured by Tokyo Chemical Industry Co., Ltd.) was used.

[0054] Triethylenetetramine has a molecular weight of 146.24, six active hydrogens, and an amine equivalent of 24.4.

[0055] 2-1-6. Example 6 The thermally conductive rubber composition of Example 6 was obtained in the same manner as in Example 1, except that an aliphatic amine compound (1,6-diaminohexane, manufactured by Tokyo Chemical Industry Co., Ltd.) was used.

[0056] 1,6-Diaminohexane has a molecular weight of 116.21, four active hydrogens, and an amine equivalent of 29.1.

[0057] 2-1-7. Example 7 The thermally conductive rubber composition of Example 7 was obtained in the same manner as in Example 1, except that an aliphatic amine compound (1,8-diaminooctane, manufactured by Tokyo Chemical Industry Co., Ltd.) was used.

[0058] 1,8-Diaminooctane has a molecular weight of 144.26, four active hydrogens, and an amine equivalent of 36.1.

[0059] 2-1-8. Example 8 Except for changing the amount of aliphatic amine compound to 5 parts by mass (phr), the thermally conductive rubber composition of Example 8 was obtained in the same manner as in Example 1.

[0060] 2-1-9. Example 9 Except for changing the amount of aliphatic amine compound to 20 parts by mass (phr), the thermally conductive rubber composition of Example 9 was obtained in the same manner as in Example 1.

[0061] 2-1-10. Example 10 Except for changing the amount of aliphatic amine compound to 30 parts by mass (phr), the thermally conductive rubber composition of Example 10 was obtained in the same manner as in Example 1.

[0062] 2-1-11. Comparative Example 1 Except for omitting the aliphatic amine compound, the thermally conductive rubber composition of Comparative Example 1 was obtained in the same manner as in Example 1.

[0063] 2-1-12. Comparative Example 2 The thermally conductive rubber composition of Comparative Example 2 was obtained in the same manner as in Example 1, except that a plasticizer (PW-380, manufactured by Idemitsu Kosan Co., Ltd.) was used instead of an aliphatic amine compound.

[0064] 2-1-13. Comparative Example 3 The thermally conductive rubber composition of Comparative Example 3 was obtained in the same manner as in Example 1, except that octyltriethoxysilane (KBE-3083, manufactured by Shin-Etsu Silicone Co., Ltd.) was used instead of the aliphatic amine compound.

[0065] 2-2. Characterization of thermally conductive rubber compositions For each thermally conductive rubber composition of Examples 1 to 10 and Comparative Examples 1 to 3, thermal conductivity, hardness (Shore hardness), tensile strength at break, and elongation at break were measured. The results are shown in... Figure 3 middle.

[0066] Figure 3 Tables illustrating the properties of the thermally conductive rubber compositions of Examples 1 to 10 and Comparative Examples 1 to 3 are provided. Shore hardness (Type A) was measured using a Type A Shore hardness tester according to JIS K 6253-3:2012. Thermal conductivity was measured according to ASTM D7984. Tensile strength at break and elongation at break were measured according to JIS K 6251.

[0067] like Figure 3As shown, the thermally conductive rubber compositions of Examples 1 to 10 exhibit thermal conductivity (3.0 W / mK or higher) and tensile strength at break comparable to those of the thermally conductive rubber compositions of Comparative Examples 1 to 3. However, compared to the thermally conductive rubber compositions of Comparative Examples 1 to 3, the thermally conductive rubber compositions of Examples 1 to 10 exhibit lower hardness and significantly higher elongation at break (300% or higher). Therefore, the thermally conductive rubber compositions of Examples 1 to 10 are superior to the thermally conductive rubber compositions of Comparative Examples 1 to 3 in terms of flexibility.

[0068] The thermally conductive rubber compositions of Examples 1 to 10 each have a Shore hardness of 80 or lower. Specifically, the thermally conductive rubber compositions of Examples 1 to 4, 9, and 10 each have a Shore hardness significantly lower than 80. In contrast, the thermally conductive rubber compositions of Comparative Examples 1 to 3 each have a Shore hardness significantly higher than 80.

[0069] 3. Appendix The following aspects are derived from the above implementation methods or modifications thereof.

[0070] (Appendix 1) Aspect 1 is a preferred embodiment of the thermally conductive rubber composition disclosed herein, comprising a matrix rubber, a thermally conductive filler, and an aliphatic amine compound. This thermally conductive rubber composition has a Shore hardness of 80 or lower (Type A), a thermal conductivity of 3.0 W / mK or higher, and an elongation at break of 300% or greater.

[0071] In this respect, the use of aliphatic amine compounds improves the dispersibility of thermally conductive fillers in the matrix rubber. This improved dispersibility allows for a reduction in the hardness of the thermally conductive rubber composition even when the thermal conductivity of the composition is increased.

[0072] Aliphatic amine compounds are also less likely to undergo self-reactions, such as reactions between silane coupling agents. Compared to aspects using silane coupling agents, thermally conductive rubber compositions exhibit lower hardness and higher elongation at break.

[0073] Even with increased thermal conductivity, the thermally conductive rubber composition still exhibits improved flexibility and excellent heat dissipation.

[0074] (Appendix 2) Aspect 2 is a preferred embodiment of aspect 1, wherein the amount of aliphatic amine compound contained is 5 parts by mass or more and 30 parts by mass or less relative to 100 parts by mass of the base rubber.

[0075] In this respect, the properties of the base rubber are maintained, and the dispersion of thermally conductive fillers in the base rubber is improved.

[0076] (Appendix 3) Aspect 3 is a preferred embodiment of aspect 1 or aspect 2, wherein the aliphatic amine compound has an amine equivalent of 135 or less.

[0077] In this respect, the dispersibility of thermally conductive fillers in the matrix rubber is improved.

[0078] (Appendix 4) Aspect 4 is a preferred embodiment of any one of aspects 1 to 3, wherein the aliphatic amine compound comprises CH3(CH2). n Compounds represented by NH2 (where n is a natural number of 10 or greater and 20 or less).

[0079] In this respect, the dispersibility of thermally conductive fillers in the matrix rubber is improved.

[0080] (Appendix 5) Aspect 5 is a preferred embodiment of any one of aspects 1 to 4, wherein the aliphatic amine compound includes triethylenetetramine.

[0081] In this respect, the dispersibility of thermally conductive fillers in the matrix rubber is improved.

[0082] (Appendix 6) Aspect 6 is a preferred embodiment of any one of aspects 1 to 5, wherein the aliphatic amine compound comprises NH2(CH2). n Compounds represented by NH2 (where n is a natural number of 6 or greater and 8 or less).

[0083] In this respect, the dispersibility of thermally conductive fillers in the matrix rubber is improved.

[0084] (Appendix 7) Aspect 7 is a preferred embodiment of any one of aspects 1 to 6. In aspect 7, the amount of thermally conductive filler contained is preferably 1,500 parts by mass or higher and 1,800 parts by mass or lower relative to 100 parts by mass of the matrix rubber.

[0085] In this respect, the thermal conductivity of the thermally conductive rubber composition has been improved and the hardness has been reduced.

[0086] (Appendix 8) Aspect 8 is a preferred embodiment of any one of aspects 1 to 7. In aspect 8, the thermally conductive filler includes at least one filler selected from the group consisting of metal oxide fillers, metal nitride fillers and metal oxynitride fillers.

[0087] In this respect, the overall insulation of the thermally conductive rubber composition is ensured, and the thermal conductivity of the thermally conductive rubber composition is improved.

[0088] (Appendix 9) Aspect 9 is a preferred embodiment of any one of aspects 1 to 8, wherein the thermally conductive filler includes zinc oxide filler.

[0089] In this respect, the thermal conductivity of the thermally conductive rubber composition is improved.

[0090] (Appendix 10) Aspect 10 is a preferred embodiment of any one of aspects 1 to 9, wherein the thermally conductive filler has an average particle size of 30 μm or larger and 70 μm or smaller.

[0091] In this respect, the thermal conductivity of the thermally conductive rubber composition has been improved and the hardness has been reduced.

[0092] (Appendix 11) Aspect 11 is a preferred embodiment of any one of aspects 1 to 10. In aspect 11, the thermally conductive filler includes: a first filler; and a second filler, wherein the average particle size of the second filler is smaller than the average particle size of the first filler. The content of the first filler is higher than the content of the second filler.

[0093] In this respect, the average particle size and filling rate of the thermally conductive filler were improved. This resulted in an increase in the thermal conductivity of the thermally conductive rubber composition and a decrease in its hardness.

[0094] (Appendix 12) Aspect 12 is a preferred embodiment of any one of aspects 1 to 11, wherein the thermally conductive rubber composition has a Shore hardness of 40 or higher (Type A).

[0095] In this respect, the thermally conductive rubber composition is flexible.

[0096] (Appendix 13) Aspect 13 is a preferred embodiment of any one of aspects 1 to 12, wherein the base rubber comprises at least one rubber selected from the group consisting of ethylene-propylene-diolefin rubber, silicone rubber, acrylic rubber, nitrile rubber and fluororubber.

[0097] In this respect, the thermal conductivity of the thermally conductive rubber composition has been improved and the hardness has been reduced.

[0098] Explanation of reference numerals in the attached figures 10... Thermally conductive rubber composition, 11... Rubber portion, 12... Thermally conductive filler.

Claims

1. A thermally conductive rubber composition comprising: Matrix rubber; Thermally conductive fillers; and Aliphatic amine compounds, in, The thermally conductive rubber composition has the following characteristics: Shore hardness of 80 or lower (Type A); Thermal conductivity of 3.0 W / mK or higher; and 300% or greater elongation at break.

2. The thermally conductive rubber composition according to claim 1, wherein, The amount of the aliphatic amine compound contained is 5 parts by mass or more and 30 parts by mass or less, relative to 100 parts by mass of the matrix rubber.

3. The thermally conductive rubber composition according to claim 2, wherein, The aliphatic amine compound has an amine equivalent of 135 or lower.

4. The thermally conductive rubber composition according to claim 3, wherein, The aliphatic amine compounds include those composed of CH3(CH2). n NH2 represents a compound where n is a natural number of 10 or greater and 20 or less.

5. The thermally conductive rubber composition according to claim 3, wherein, The aliphatic amine compound includes trimethylenetetramine.

6. The thermally conductive rubber composition according to claim 3, wherein, The aliphatic amine compounds include those composed of NH2(CH2). n NH2 represents a compound where n is a natural number of 6 or greater and 8 or less.

7. The thermally conductive rubber composition according to claim 1, wherein, The amount of the thermally conductive filler contained is 1,500 parts by weight or more and 1,800 parts by weight or less, relative to 100 parts by weight of the matrix rubber.

8. The thermally conductive rubber composition according to any one of claims 1 to 7, wherein, The thermally conductive filler includes at least one filler selected from the group consisting of metal oxide fillers, metal nitride fillers, and metal oxynitride fillers.

9. The thermally conductive rubber composition according to claim 8, wherein, The thermally conductive filler includes zinc oxide filler.

10. The thermally conductive rubber composition according to any one of claims 1 to 7, wherein, The thermally conductive filler has an average particle size of 30 μm or larger and 70 μm or smaller.

11. The thermally conductive rubber composition according to claim 10, wherein, The thermally conductive filler includes: First packing; and The second packing material has an average particle size smaller than that of the first packing material, and The content of the first filler is higher than the content of the second filler.

12. The thermally conductive rubber composition according to any one of claims 1 to 7, wherein, The thermally conductive rubber composition has a Shore hardness of 40 or higher (Type A).

13. The thermally conductive rubber composition according to any one of claims 1 to 7, wherein, The base rubber includes at least one rubber selected from the group consisting of ethylene-propylene-diolefin rubber, silicone rubber, acrylic rubber, nitrile rubber, and fluororubber.

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