Thermal interface material containing spherical fillers with a multimodal distribution

Abstract

Disclosed herein is a thermal interface material comprising a mixture of a thermosetting binder component and a spherical, thermally conductive filler, and its use in battery-powered vehicles.

Description

Technical Field

[0001] The present disclosure relates to thermal interface materials and their use in battery electric vehicles.

Background Art

[0002] Compared with conventional transportation means, battery electric vehicles have great advantages such as light weight and reduced CO₂ emissions. However, many technical problems still need to be overcome to ensure optimal use of the technology. For example, one of the current efforts in the industry is to increase the driving range of battery electric vehicles by developing high energy density batteries. And this leads to the need to develop better thermal management systems for high energy density batteries.

[0003] In a battery electric vehicle, the battery cells or modules are thermally connected to the cooling unit by a thermal interface material (TIM). Such a TIM is typically formed from a polymeric material filled with thermally conductive filler. One method for obtaining a TIM with high thermal conductivity is to incorporate a high loading of thermally conductive filler. However, when the filler loading is high, the viscosity of the TIM may become too high to be useful. Therefore, there is still a need for developing TIMs with high thermal conductivity and low viscosity.

Summary of the Invention

Means for Solving the Problems

[0004] In a first aspect, the present invention provides a thermal interface material composition comprising a) a polymer binder component, and b) about 85 to 95% by weight of a mixture of spherical thermally conductive fillers, wherein the total weight of the composition is 100% by weight in total, and based on the total weight of the mixture of spherical thermally conductive fillers, the mixture comprises i) about 15 to 40% by weight of a first thermally conductive filler which is spherical and has a particle size distribution D 50 in the range of about 0.1 to 20 μm, and ii) a second thermally conductive filler which is spherical and has a particle size distribution D 50The present invention provides a thermal interface material composition comprising approximately 50-80% by weight of a second thermally conductive filler having [a certain property].

[0005] In a second aspect, the present invention relates to a thermal interface material composition comprising a) a polymer binder component and b) about 85-95% by weight of a thermally conductive filler, wherein the total weight of the composition is 100% by weight, and the thermally conductive filler has a particle size distribution D of approximately 0.1-2 μm, based on its total weight, being spherical or non-spherical. 50 ii) a first thermally conductive filler having approximately 0.5-10% by weight, and a particle size distribution D that is spherical and in the range of approximately 3-10 μm. 50 iii) a second thermally conductive filler having approximately 10-35% by weight, and a particle size distribution D that is spherical and in the range of approximately 40-150 μm 50 The present invention provides a thermal interface material composition comprising approximately 50-80% by weight of a third thermally conductive filler having the properties of [a specific substance].

[0006] In one embodiment of the thermal interface material composition, the composition contains a polymer binder component in an amount of about 1 to 10% by weight, based on the total weight of the composition.

[0007] In further embodiments of the thermal interface material composition, the first, second, and third thermally conductive fillers are independently selected from the group consisting of Al2O3, Al, Mg(OH)2, MgO2, SiO2, boron nitride, and mixtures thereof. In a second aspect of the present invention, the first spherical or non-spherical thermally conductive filler i) can be selected from the group consisting of Al2O3, Al, TiO2, ZnO, Mg(OH)2, MgO2, SiO2, boron nitride, Al(OH)3 (aluminum hydroxide), and mixtures thereof.

[0008] In yet another embodiment of the thermal interface material composition, the first, second, and third thermally conductive fillers are Al2O3 particles.

[0009] In another embodiment of the second aspect, the first thermally conductive filler i) is selected from Al2O3, aluminum hydroxide, and mixtures thereof.

[0010] In a preferred embodiment of the second aspect, the first thermally conductive filler i) is selected from Al₂O₃, aluminum hydroxide, and mixtures thereof, and the second thermally conductive filler ii) is Al₂O₃.

[0011] In another preferred embodiment of the second aspect, the first thermally conductive filler i) is selected from Al₂O₃, aluminum hydroxide, and mixtures thereof, the second thermally conductive filler ii) is Al₂O₃, and the third thermally conductive filler iii) is Al₂O₃.

[0012] In still another embodiment of the thermal interface material composition according to the first aspect, the first thermally conductive filler has a particle size distribution D in the range of about 0.5 to 15 μm 50 , and the second thermally conductive filler has a particle size distribution D in the range of about 40 to 120 μm 50 .

[0013] In still another embodiment of the thermal interface material composition according to the second aspect, the first thermally conductive filler i) has a particle size distribution D in the range of about 0.5 to 15 μm, more preferably 0.6 to 2 μm 50 .

[0014] In still another embodiment of the thermal interface material composition according to the second aspect, the second thermally conductive filler ii) has a particle size distribution D in the range of about 3 to 10 μm, preferably 3 to 6 μm 50 .

[0015] In still another embodiment of the thermal interface material composition according to the second aspect, the third thermally conductive filler iii) has a particle size distribution D in the range of about 40 to 150 μm, preferably 50 to 100 μm, more preferably 55 to 85 μm 50 .

[0016] In still another embodiment of the thermal interface material composition according to the first aspect, the second thermally conductive filler has a particle size distribution D in the range of about 40 to 90 μm 50 .

[0017] In yet another embodiment of the thermal interface material composition of the first aspect, the composition comprises about 18 to 38% by weight of a first thermal conductive filler and about 50 to 78% by weight of a second thermal conductive filler, based on the total weight of the composition.

[0018] In yet another embodiment of the thermal interface material composition of the first aspect, the composition comprises about 20 to 35% by weight of a first thermal conductive filler and about 53 to 75% by weight of a second thermal conductive filler, based on the total weight of the composition.

[0019] In yet another embodiment of the thermal interface material composition of the second aspect, the composition comprises about 1 to 7% by weight, more preferably 2 to 5% by weight, of the first thermally conductive filler based on the total weight of the composition.

[0020] In yet another embodiment of the thermal interface material composition of the second aspect, the composition comprises about 10 to 30% by weight, more preferably 12 to 28% by weight, of the total weight of the composition, of a second thermally conductive filler.

[0021] In yet another embodiment of the thermal interface material composition of the second aspect, the composition comprises about 50 to 75% by weight, more preferably 50 to 68% by weight, of the total weight of the composition, of a third thermally conductive filler.

[0022] In yet another embodiment of the thermal interface material composition of the second aspect, the composition comprises about 2 to 5% by weight of a first thermal conductive filler, 12 to 28% by weight of a second thermal conductive filler, and 50 to 68% by weight of a third thermal conductive filler, based on the total weight of the composition.

[0023] In yet another embodiment of the thermal interface material composition of the second aspect, the composition comprises, based on the total weight of the composition, about 7% by weight of a first thermally conductive filler, 26% by weight of a second thermally conductive filler, and 60% by weight of a third thermally conductive filler.

[0024] In yet another embodiment of the thermal interface material composition of the second aspect, the first thermal conductive filler i) is non-spherical and has a particle size distribution D in the range of about 0.1 to 2 μm. 50Al2O3 having the following characteristics: The second thermally conductive filler (ii) is spherical and has a particle size distribution D in the range of approximately 3 to 10 μm. 50 Al2O3 having the following characteristics, and the third thermally conductive filler (iii) is spherical and has a particle size distribution D in the range of approximately 40 to 150 μm. 50 It is Al2O3 containing [a specific compound].

[0025] In yet another embodiment of the thermal interface material of the second aspect, the first thermal conductive filler i) is non-spherical and has a particle size distribution D in the range of about 0.1 to 2 μm. 50 The second thermally conductive filler is aluminum hydroxide [Al(OH)3], and the second thermally conductive filler (ii) is spherical with a particle size distribution of approximately 3-10 μm D 50 Al2O3 having the following characteristics: The third thermally conductive filler (iii) is spherical and has a particle size distribution of approximately 40-150 μm D 50 It is Al2O3 containing [a specific compound].

[0026] In yet another embodiment of the thermal interface material of the second aspect, the first thermal conductive filler i) is present in 0.5 to 10% by weight and has a non-spherical particle size distribution D in the range of about 0.1 to 2 μm. 50 It is Al2O3 having the following properties, and the second thermally conductive filler (ii) is present in 10-35% by weight and is spherical with a particle size distribution of approximately 3-10 μm D 50 It is Al2O3 having the following properties, and the third thermally conductive filler (iii) is present at 50-80% by weight and is spherical with a particle size distribution of approximately 40-150 μm D 50 It is Al2O3 containing [a specific compound].

[0027] In yet another embodiment of the thermal interface material of the second aspect, the first thermal conductive filler i) is present in 0.5 to 10% by weight and has a non-spherical particle size distribution D in the range of about 0.1 to 2 μm. 50 The aluminum hydroxide [Al(OH)3] has the following properties: the second thermally conductive filler (ii) is present in 10-35% by weight and is spherical with a particle size distribution of approximately 3-10 μm. 50 It is Al2O3 having the following properties, and the third thermally conductive filler (iii) is present at 50-80% by weight and is spherical with a particle size distribution of approximately 40-150 μm D 50 It is Al2O3 containing [a specific compound].

[0028] In yet another embodiment of the thermal interface material of the second aspect, the first thermal conductive filler i) is present in 0.5 to 10% by weight and has a non-spherical particle size distribution D in the range of about 0.5 to 1.5 μm. 50 It is Al2O3 having the following properties, and the second thermally conductive filler (ii) is present in 10-35% by weight and has a spherical particle size distribution of approximately 3-7 μm D 50 It is Al2O3 having the following properties, and the third thermally conductive filler (iii) is present at 50-80% by weight and has a spherical particle size distribution of approximately 50-90 μm D 50 It is Al2O3 containing [a specific compound].

[0029] In yet another embodiment of the thermal interface material of the second aspect, the first thermal conductive filler i) is present in 0.5 to 10% by weight and has a non-spherical particle size distribution D in the range of about 1 to 2 μm. 50 The aluminum hydroxide [Al(OH)3] has a second thermally conductive filler, which is present in 10-35% by weight and has a spherical particle size distribution of approximately 3-7 μm. 50 It is Al2O3 having the following properties, and the third thermally conductive filler (iii) is present at 50-80% by weight and has a spherical particle size distribution of approximately 50-90 μm D 50 It is Al2O3 containing [a specific compound].

[0030] This specification further provides articles comprising the above-described thermal interface material compositions.

[0031] In one embodiment of the article, the article further includes a battery module formed of one or more battery cells and a cooling unit, the battery module being connected to the cooling unit via a thermal interface material composition. [Modes for carrying out the invention]

[0032] According to a first embodiment, a thermal interface material (TIM) is disclosed herein, comprising a polymer binder component and a mixture of spherical thermally conductive fillers in an amount of about 85 to 95% by weight based on the total weight of the TIM composition. The mixture of spherical thermally conductive fillers has a particle size distribution D in the range of about 0.1 to 20 μm based on the total weight. 50A first spherical thermally conductive filler having approximately 15-40% by weight, and a particle size distribution D in the range of approximately 40-150 μm 50 It contains a second spherical thermally conductive filler having approximately 50-80% by weight.

[0033] In this specification, according to a second aspect, a thermal interface material composition comprising a) a polymer binder component and b) about 85-95% by weight of a thermally conductive filler, wherein the total weight of the composition is 100% by weight, and the thermally conductive filler has a particle size distribution D of approximately 0.1-2 μm, i) spherical or non-spherical, based on its total weight. 50 ii) a first thermally conductive filler having approximately 0.5-10% by weight, and a particle size distribution D that is spherical and in the range of approximately 3-10 μm. 50 iii) a second thermally conductive filler having approximately 10-35% by weight, and a particle size distribution D that is spherical and in the range of approximately 40-150 μm 50 A thermal interface material composition is also disclosed, comprising about 50-80% by weight of a third thermally conductive filler having the same properties.

[0034] The polymer binder component can be formed from any suitable polymer material. In one embodiment, the polymer binder component is formed from an elastomer material. Examples of elastomer materials used herein, but not limited to, include polyurethane, urea, epoxy, acrylate, silicone, and silane-modified polymers (SMPs). In one embodiment, the polymer binder component is formed from polyurethane.

[0035] According to this disclosure, the polymeric binder component may be present in the TIM composition at a level of 1 to 10% by weight or about 2 to 7% by weight, based on the total weight of the TIM composition.

[0036] The terms "spherical" or "spherical" are used herein to refer to an isotropic shape, that is, a shape in which the extent (particle size) is approximately the same in all directions. In particular, for a particle to be isotropic, the ratio of the maximum length to the minimum length of the chord intersecting the geometric center of the particle's convex hull must not exceed the ratio of the smallest isotropic regular polyhedron, i.e., a tetrahedron.

[0037] The shape of the particles can be evaluated by examination under a scanning electron microscope. Spherical particles appear spherical under a scanning electron microscope at a magnification of 400 to 5500 ×, preferably 5000 ×. Preferably, the particles also have an aspect ratio of 1 to 1.2, preferably 1 to 1.1.

[0038] The shape of a particle is often defined by its aspect ratio, which is expressed as the ratio of the particle's major axis to its thickness. In some embodiments, the aspect ratio of a spherical or spherical filler is in the range of about 1 to 3, or about 1 to 2, more preferably 1 to 1.2.

[0039] The term "thermally conductive filler" is intended to refer to filler materials in their pure form with a thermal conductivity exceeding 2 W / mK as measured according to ASTM 5470.

[0040] Furthermore, the particle size distribution D, also known as the median diameter or median value of the particle size distribution 50 This is the particle size value at 50% of the cumulative distribution. For example, D 50 If = 10 μm, then 50% of the particles in the sample have an average diameter greater than 10 μm, and 50% of the particles have an average diameter less than 10 μm. Particle size distribution D of one group of particles. 50This can be determined, for example, by using a light scattering method according to ASTM B822-10 or ASTM B822-20, using water or acetone as the suspension medium, or by using a laser diffraction method according to ASTM B822-10, ASTM B822-20, or ISO 13320, using water or acetone as the suspension medium. Preferably, laser diffraction according to ISO 13320 is used, and water is used as the suspension medium.

[0041] The spherical thermally conductive fillers used herein can be formed from any suitable material, including but not limited to Al2O3, Al, Mg(OH)2, MgO2, SiO2, and boron nitride. In a first embodiment, the mixture of spherical thermally conductive fillers consists of at least two groups of fillers having different particle size distributions, namely, particle size distributions D in the range of about 0.1 to 20 μm or about 0.5 to 15 μm. 50 A first spherical thermally conductive filler having a particle size distribution D in the range of approximately 40-150 μm, approximately 40-120 μm, or approximately 40-90 μm. 50 A second spherical thermal conductive filler having a particle size distribution D different from that of the first and second spherical thermal conductive fillers. Based on the total weight of the spherical thermal conductive fillers, the first spherical thermal conductive filler can be present at a level of about 15-40% by weight, or about 18-38% by weight, or about 20-35% by weight, and the second spherical thermal conductive filler can be present at a level of about 50-80% by weight, or about 50-78% by weight, or about 53-75% by weight. The first and second fillers may be formed from the same or different thermal conductive materials. Furthermore, each of the first and second fillers may be composed of one or more materials. In addition, the mixture of spherical thermal conductive fillers may have a particle size distribution D different from that of the first and second spherical thermal conductive fillers. 50 The present invention may further include an additional group of spherical thermally conductive fillers having the following characteristics: In one embodiment, the mixture of spherical thermally conductive fillers is spherical Al2O3 particles.

[0042] The spherical thermally conductive fillers used herein can be formed from any suitable material, including but not limited to Al2O3, Al, Mg(OH)2, MgO2, SiO2, and boron nitride. In a second embodiment, a mixture of spherical and non-spherical thermally conductive fillers consists of at least three groups of fillers having different particle size distributions, i) a particle size distribution D in the range of about 0.1 to 2 μm 50 ii) a first spherical or non-spherical thermal conductive filler having a particle size distribution D in the range of approximately 3 to 10 μm 50 iii) a second thermally conductive filler having a spherical particle size distribution D in the range of approximately 40-150 μm 50 A third thermally conductive filler having the following characteristics. The first, second, and third fillers may be formed from the same or different thermally conductive materials. Furthermore, each of the first, second, and third fillers may be composed of one or more materials. In addition, a mixture of spherical or non-spherical thermally conductive fillers may have a different particle size distribution D than the first and second spherical thermally conductive fillers. 50 The present invention may further include an additional group of spherical thermally conductive fillers. In one embodiment, the mixture of spherical thermally conductive fillers is spherical Al2O3 particles.

[0043] Furthermore, the spherical thermally conductive filler may be surface-treated with, for example, fatty acids, silanes, zirconium-based coupling agents, titanate coupling agents, carboxylates, etc.

[0044] A mixture of spherical thermally conductive fillers may be present in the TIM composition at a level of approximately 85–95% by weight, based on the total weight of the TIM composition.

[0045] Furthermore, the TIM compositions disclosed herein may optionally further contain other suitable additives such as catalysts, plasticizers, stabilizers, adhesion promoters, fillers, and colorants. Such optional additives may be present at levels of up to about 10% by weight, up to about 8% by weight, or up to about 5% by weight, based on the total weight of the TIM.

[0046] As shown in the following examples, when a mixture of spherical thermally conductive fillers (15-40% by weight of those with a particle size distribution in the range of approximately 0.1-20 μm and 50-80% by weight of those with a particle size distribution in the range of approximately 40-150 μm) is added, a TIM with low viscosity and high conductivity can be obtained.

[0047] As shown in the following examples, according to a second aspect of the present invention, the particle size distribution D in the range of about 0.1 to 2 μm 50 When a mixture of spherical and non-spherical thermally conductive fillers is added, a TIM with low viscosity and high conductivity is obtained.

[0048] This specification further discloses a battery pack system in which a cooling unit or plate therein is coupled to a battery module (formed from one or more battery cells) via the aforementioned TIM, thereby enabling heat to be conducted between them. In one embodiment, the battery pack system is used in a battery-powered vehicle. The present specification includes the following embodiments. Section 1. a) A polymer binder component, b) A mixture of spherical and thermally conductive fillers in an amount of approximately 85-95% by weight, A thermal interface material composition comprising, The total weight of the aforementioned composition is 100% by weight. The mixture of spherical and thermally conductive fillers has, based on their total weight, i) a particle size distribution D in the range of approximately 0.1 to 20 μm, being spherical. 50 ii) a first thermally conductive filler having approximately 15-40% by weight, and a particle size distribution D that is spherical and in the range of approximately 40-150 μm 50 A thermal interface material composition comprising about 50-80% by weight of a second thermally conductive filler having [a certain property]. Section 2. The thermal interface material composition according to claim 1, comprising about 1 to 10% by weight of the polymer binder component based on the total weight of the composition. Section 3. The thermal interface material composition according to claim 1, wherein the first and second thermally conductive fillers are independently selected from the group consisting of Al2O3, Al, Mg(OH)2, MgO2, SiO2, boron nitride, and mixtures thereof. Section 4. The thermal interface material composition according to item 3, wherein the first and second thermally conductive fillers are Al2O3 particles. Section 5. The first thermally conductive filler has a particle size distribution D in the range of approximately 0.5 to 15 μm. 50 The second thermally conductive filler has a particle size distribution D in the range of approximately 40 to 120 μm. 50 A thermal interface material composition according to item 1, having the following characteristics. Section 6. The second thermally conductive filler has a particle size distribution D in the range of approximately 40 to 90 μm. 50 A thermal interface material composition according to item 5, having the following characteristics. Section 7. The thermal interface material composition according to claim 1, comprising about 18 to 38% by weight of the first thermal conductive filler and about 50 to 78% by weight of the second thermal conductive filler, based on the total weight of the composition. Section 8. The thermal interface material composition according to claim 7, comprising about 20 to 35% by weight of the first thermal conductive filler and about 53 to 75% by weight of the second thermal conductive filler, based on the total weight of the composition. Section 9. An article comprising the thermal interface material composition described in item 1. Section 10. The article according to claim 9, further comprising a battery module formed from one or more battery cells, and a cooling unit, wherein the battery module is connected to the cooling unit via the thermal interface material composition. Section 11. a) a polymer binder component and b) a thermal interface material composition comprising approximately 85-95% by weight of a thermally conductive filler, wherein the total weight of the composition is 100% by weight, and the thermally conductive filler has a particle size distribution D of approximately 0.1-2 μm, which is spherical or non-spherical, based on its total weight. 50ii) a first thermally conductive filler having approximately 0.5-10% by weight, and a particle size distribution D that is spherical and in the range of approximately 3-10 μm. 50 iii) a second thermally conductive filler having approximately 10-35% by weight, and a particle size distribution D that is spherical and in the range of approximately 40-150 μm 50 A thermal interface material composition comprising approximately 50-80% by weight of a third thermally conductive filler having [a certain property]. Section 12. The first thermally conductive filler i) has a particle size distribution D in the range of approximately 0.5 to 5 μm, more preferably 0.6 to 2 μm. 50 A thermal interface material composition according to item 11, having the following characteristics. Section 13. The second thermally conductive filler ii) has a particle size distribution D in the range of approximately 3 to 10 μm, preferably 3 to 6 μm. 50 A thermal interface material composition according to item 11 or 12, having the following characteristics. Section 14. The third thermally conductive filler (iii) has a particle size distribution D in the range of approximately 40 to 150 μm, preferably 50 to 100 μm, and more preferably 55 to 85 μm. 50 A thermal interface material composition according to item 11, 12, or 13, having the following: Section 15. A thermal interface material composition according to any one of claims 11 to 14, comprising about 1 to 10% by weight of a polymer binder component based on the total weight of the composition. Section 16. The thermal interface material composition according to any one of claims 11 to 15, wherein the first, second, and third thermally conductive fillers are independently selected from the group consisting of Al2O3, aluminum hydroxide, Mg(OH)2, MgO2, SiO2, ZnO, TiO2, boron nitride, and mixtures thereof. Section 17. A thermal interface material composition according to any one of claims 11 to 16, wherein the first thermally conductive filler is aluminum hydroxide and the second and third thermally conductive fillers are Al2O3 particles. Section 18. The thermal interface material composition according to any one of claims 11 to 17, wherein the first thermally conductive filler i) is present in an amount of 1 to 7% by weight, preferably 2 to 5% by weight, based on the total weight of the composition. Section 19. The thermal interface material composition according to any one of claims 11 to 18, wherein the second thermal conductive filler ii) is present in an amount of 10 to 30% by weight, preferably 12 to 28% by weight, based on the total weight of the composition. Section 20. The thermal interface material composition according to any one of claims 11 to 19, wherein the third thermal conductive filler (iii) is present in an amount of 50 to 75% by weight, preferably 50 to 68% by weight, based on the total weight of the composition. Section 21. Particle size distribution D 50 A thermal interface material composition according to any one of items 1 to 8 or 11 to 20, wherein water is used as the suspension medium and the composition is measured by laser diffraction in accordance with ISO 13320. Section 22. The thermal interface material composition according to any one of claims 1 to 8 or 11 to 21, wherein the spherical filler is a filler that appears spherical under a scanning electron microscope at a magnification of 400 to 5500 ×, preferably 5000 ×. Section 23. The thermal interface material composition according to any one of claims 1 to 8 or 11 to 22, wherein the spherical filler has an aspect ratio of 1 to 1.2, preferably 1 to 1.1. Section 24. A battery pack system comprising a battery module formed from one or more battery cells and a cooling unit, wherein the battery module is connected to the cooling unit via a thermal interface material composition according to any one of claims 1 to 8 or 11 to 23. [Examples]

[0049] material • Amine-1 Trifunctional polyetheramine • Amine-2 bifunctional polyetheramine • Plasticizer: Methylated rapeseed oil; • Stabilizer (Product name: Calofort) TM Precipitated calcium carbonate obtained from Keyser & Mackay as SV; • Catalyst from Evonik, product name Dabco TM 33% triethylenediamine dissolved in 67% dipropylene glycol, obtained as LV33; • Acrylate: Ethoxylated trimethylolpropane triacrylate obtained from Sartomer; • Product name: Desmoseal from STP Covestro TM Aliphatic silane-terminated urethane prepolymer obtained as S XP2636; • Prepolymer: Reaction product of aromatic toluene diisocyanate (TDI)-based polyisocyanate prepolymer with cardanol; • Coloring agent: Coloring paste obtained from Huntsman under the product name Araldit DW 0134Gruen; ·Al2O3-s-1 particle size distribution D 50 20% by weight of particles with a size of 0.7 μm, and particle size distribution D 50 10% by weight of particles with a size of 5.9 μm, and particle size distribution D 50 Trimodulus spherical Al2O3 particles, consisting of 70% by weight of particles with a diameter of 79 μm and an aspect ratio of less than 1.2; ·Al2O3-p-1 particle size distribution D 50 20% by weight of particles with a size of 0.7 μm, and particle size distribution D 50 10% by weight of particles with a size of 5.9 μm, and particle size distribution D 50 Trimodulus non-spherical Al2O3 particles, consisting of 70% by weight of particles with a diameter of 79 μm and an aspect ratio greater than 1.2; ·ATH-1 particle size distribution D 50 Particles with a diameter of less than 10 μm and particle size distribution D 50 Non-spherical aluminum trihydrate with a bimodal distribution and an aspect ratio greater than 1.2, composed of particles larger than 50 μm; ·ATH-2 particle size distribution D 50Monomodulus aluminum trihydrate (non-spherical) with a diameter of 2 μm and an aspect ratio greater than 1.2; ·ATH-3 particle size distribution D 50 Monomodulus aluminum trihydrate (non-spherical) with a diameter of 50 μm and an aspect ratio greater than 1.2; ·ATH-4 particle size distribution D 50 Monomodulus aluminum trihydrate (non-spherical) with a diameter of 1.5 μm and an aspect ratio greater than 1.2; ·Al2O3-p-2 particle size distribution D 50 Monomodulus, non-spherical Al2O3 particles with a diameter of 5 μm and an aspect ratio greater than 1.2; ·Al2O3-p-3 particle size distribution D 50 Monomodulus, non-spherical Al2O3 particles with a diameter of 70 μm and an aspect ratio greater than 1.2; ·Al2O3-p-4 particle size distribution D 50 Non-spherical Al2O3 particles with a diameter of 0.8 μm and an aspect ratio greater than 1.2; ·Al2O3-s-2 particle size distribution D 50 Monomodulus spherical Al2O3 particles with a diameter of 5 μm and an aspect ratio of less than 1.2; ·Al2O3-s-3 particle size distribution D 50 Monomodulus spherical Al2O3 particles with a diameter of 70 μm and an aspect ratio of less than 1.2; • Particle size distribution D obtained from Al-s Eckhart 50 Monomodulus spherical Al particles with a diameter of 14 μm and an aspect ratio of less than 1.2; Titanium dioxide particles obtained from TiO2Kronos International Inc. ·Al2O3-s-4 particle size distribution D 50 Monomodulus spherical Al2O3 particles with a diameter of 0.7 μm and an aspect ratio of less than 1.2; ·Al-p-1 particle size distribution D 50Monomodulus, non-spherical Al particles with a diameter of 8 μm and an aspect ratio greater than 1.2; ·Al-p-2 particle size distribution D 50 Monomodulus, non-spherical Al particles with a diameter of 80 μm and an aspect ratio greater than 1.2;

[0050] The particle size distribution was measured by laser diffraction in accordance with ISO 13320, using water as the suspension medium.

[0051] Particle shape was evaluated by examination under a scanning electron microscope. Spherical particles were defined as particles that appeared spherical under a scanning electron microscope at a magnification of 5000× and had an aspect ratio of less than 1.2.

[0052] Comparative Examples CE1-CE8 and Examples E1-E7, E8 and E9 For CE1-CE8 and E1-E7, E8, and E9, Part A and Part B were prepared separately by mixing the components listed in Table 1 (first liquid component, then solid component). The viscosity (using an Anton-Paar NMC 202 rheometer) and thermal conductivity (according to ASTM 5470) of Part A and Part B were measured and summarized in Table 1. Then, Part A and Part B were mixed in a 1:1 volume ratio using a Speedmixer for 20 seconds to obtain the final thermal interface material (TIM). The thermal conductivity of the TIM was also measured and summarized in Table 1.

[0053] As shown here, when a mixture of spherical thermally conductive fillers (15-40% by weight with a particle size distribution in the range of approximately 0.1-20 μm and 50-80% by weight with a particle size distribution in the range of approximately 40-150 μm) was added, a TIM with low viscosity and high conductivity was obtained.

[0054] Examples E8 and E9 are examples of a second aspect of the present invention, i) a particle size distribution D that is spherical or non-spherical and in the range of about 0.1 to 2 μm 50 A first thermally conductive filler having [Al2O3-p-4, D 50 0.8μm (Ex8), ATH-4, D50 1.5 μm (Ex. 9) and ii) spherical with a particle size distribution in the range of approximately 3 to 10 μm D 50 A second thermally conductive filler having (Al2O3-s-2, D 50 iii) 5 μm, and a particle size distribution D that is spherical and in the range of approximately 40-150 μm. 50 A third thermally conductive filler having (Al2O3-s-3, D 50 It includes (70 μm).

[0055] [Table 1]

[0056] [Table 2]

Claims

1. a) Polymer binder component, b) A mixture of 85-95% by weight of spherical and thermally conductive fillers, A thermal interface material composition comprising, The total weight of the aforementioned composition is 100% by weight. The mixture of spherical and thermally conductive fillers, based on their total weight, i) Spherical particle size distribution D in the range of 0.1 to 20 μm ５０ ii) Al particles, which are a first thermally conductive filler, and Al particles, which are a second thermally conductive filler, which are spherical and have a particle size distribution D50 in the range of 0.1 to 20 μm, in a total of 15 to 40% by weight. iii) Spherical with a particle size distribution in the range of 40-150 μm D ５０ The material contains 50 to 80% by weight of Al₂O₃ particles, which are a third thermally conductive filler, Thermal interface material composition.

2. The thermal interface material composition according to claim 1, comprising 1 to 10% by weight of the polymer binder component based on the total weight of the composition.

3. The first and second thermally conductive fillers have a particle size distribution D in the range of 0.5 to 15 μm. ５０ The third thermally conductive filler has a particle size distribution D in the range of 40 to 120 μm. ５０ A thermal interface material composition according to claim 1 or 2, having the following characteristics.

4. The third thermally conductive filler has a particle size distribution D in the range of 40 to 90 μm. ５０ A thermal interface material composition according to any one of claims 1 to 3, having the following characteristics.

5. A thermal interface material composition according to any one of claims 1 to 4, comprising, based on the total weight of the composition, 18 to 38% by weight of the first and second thermally conductive fillers and 50 to 78% by weight of the third thermally conductive filler.

6. A thermal interface material composition according to any one of claims 1 to 5, comprising, based on the total weight of the composition, 20 to 35% by weight of the first and second thermally conductive fillers and 53 to 75% by weight of the third thermally conductive filler.

7. An article comprising the thermal interface material composition according to any one of claims 1 to 6.

8. The article according to claim 9, further comprising a battery module formed from one or more battery cells, and a cooling unit, wherein the battery module is connected to the cooling unit via the thermal interface material composition.

9. Particle size distribution D ５０ The thermal interface material composition according to any one of claims 1 to 8, wherein water is used as the suspension medium and the thermal interface material composition is measured by laser diffraction in accordance with ISO 13320.

10. The thermal interface material composition according to any one of claims 1 to 8, wherein the spherical filler is a filler that appears spherical under a scanning electron microscope at a magnification of 400 to 5500 ×.

11. The thermal interface material composition according to any one of claims 1 to 8, wherein the spherical filler has an aspect ratio of 1 to 1.

2.

12. A battery pack system comprising a battery module formed from one or more battery cells and a cooling unit, wherein the battery module is connected to the cooling unit via a thermal interface material composition according to any one of claims 1 to 8.

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