Gap filler composition and battery pack

Abstract

An embodiment of the present invention provides a gap filler composition comprising a siloxane resin, a filler containing thermally conductive inorganic particles and hollow particles, a catalyst, and an aminosilicone dispersant. By utilizing the aminosilicone dispersant and hollow particles, a gap filler composition is provided that maintains thermal conductivity while having low specific gravity and improved viscosity stability. A battery pack utilizing the gap filler composition is also provided.

Description

Technical Field

[0001] The present invention relates to a gap filler composition and a battery pack, and more specifically to a gap filler composition containing a siloxane-based resin, and a battery pack including a gap filler formed using the same. Background Art

[0002] A secondary battery is a battery that can be repeatedly charged and discharged, and is widely applied as a power source for portable electronic devices such as mobile phones and laptop computers. For example, lithium secondary batteries have high operating voltage, energy density and rate characteristics, and have recently been utilized as a power source for electric vehicles.

[0003] For example, a battery cell is defined by a lithium secondary battery, and a battery module is formed by assembling a plurality of battery cells. By assembling said battery modules, a high-capacity, high-output battery pack applicable to electric vehicles can be formed.

[0004] In order to apply a battery pack to a vehicle such as an electric vehicle, the battery pack can be placed on a battery support plate, and the battery pack can be fixed using a gap filler composition.

[0005] The application step of said gap filler composition can be included in the entire production platform of an electric vehicle. Therefore, from the viewpoint of maintaining process efficiency and reliability, there is a demand for a gap filler composition that cures within a predetermined time and provides desired physical properties.

[0006] In order to dissipate heat generated by repeated charging and discharging of said battery pack, there is a need for designing a composition that can form a gap filler having improved thermal conductivity, appropriate absorbency and / or elasticity against external impact, as well as low weight and / or specific gravity.

[0007] For example, Korean Patent No. 10-2402503 discloses the structure of a battery pack including a battery module and a gap filler. [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] One objective of the present invention is to provide a gap filler composition having improved thermal and mechanical properties.

[0009] One objective of the present invention is to provide a battery pack containing a gap filler formed from the gap filler composition described above. [Means for solving the problem]

[0010] 1. A gap filler composition comprising a siloxane resin, a filler containing thermally conductive inorganic particles and hollow particles, a catalyst, and an aminosilicone dispersant.

[0011] 2. In item 1 above, the content of the aminosilicone-based dispersant in the total weight of the composition is 0.1% by weight to 3% by weight, a gap filler composition.

[0012] 3. In item 1 above, the thermally conductive inorganic particles are a gap filler composition comprising aluminum hydroxide particles.

[0013] 4. In item 3 above, the aluminum hydroxide particles are particles that have not been surface-treated with alkyl or alkylsilane groups, a gap filler composition.

[0014] 5. In item 3 above, the content of the thermally conductive inorganic particles in the total weight of the composition is 75% to 95% by weight, a gap filler composition.

[0015] 6. In item 1 above, the hollow particles are a gap filler composition comprising hollow silica particles.

[0016] 7. The gap filler composition according to item 6, wherein the density of the hollow particles is 0.1 g / cc to 0.8 g / cc.

[0017] 8. The gap filler composition according to item 1, wherein the content of the hollow particles based on the total weight of the composition is 0.1 wt% to 5 wt%.

[0018] 9. The gap filler composition according to item 1, wherein the siloxane-based resin comprises a first siloxane-based resin having an unsaturated terminal group and a second siloxane-based resin having a saturated terminal group.

[0019] 10. The gap filler composition according to item 9, wherein the first siloxane-based resin comprises a siloxane-based resin having vinyl groups at both terminals, and the second siloxane-based resin comprises a siloxane-based resin in which hydrogen is bonded to silicon atoms at both terminals.

[0020] 11. The gap filler composition according to item 10, further comprising a crosslinking agent having methyl groups bonded to silicon atoms at both terminals.

[0021] 12. The gap filler composition according to item 9, wherein the content of the siloxane-based resin based on the total weight of the composition is 2 wt% to 23 wt%.

[0022] 13. The gap filler composition according to item 1, having a specific gravity of less than 3.

[0023] 14. The gap filler composition according to item 1, having a specific gravity of 1.5 to 1.9.

[0024] 15. A battery pack comprising a plurality of battery modules, a support plate, and a gap filler formed by using the gap filler composition according to the foregoing embodiment between the battery modules and the support plate. Effects of the Invention

[0025] A gap filler composition according to an exemplary embodiment of the present invention may include hollow particles as a filler. The filler may include thermally conductive inorganic particles, and may include aluminum hydroxide particles as the thermally conductive inorganic particles. In some embodiments, aluminum hydroxide particles that have not been subjected to surface treatment may be used.

[0026] The hollow particles reduce the specific gravity of the gap filler composition, and while maintaining thermal conductivity by the thermally conductive inorganic particles, further reduction in the specific gravity of the gap filler composition can be achieved.

[0027] Therefore, by applying the gap filler composition to a vehicle battery pack, rapid heat dissipation can be promoted against temperature rise caused by repeated charging and discharging of the battery pack while reducing the weight of the battery pack.

[0028] According to an exemplary embodiment, the gap filler composition may include an aminosilicone-based dispersant. The aminosilicone-based dispersant improves the dispersibility between the filler and the siloxane-based resin, and can enhance the storage stability of the composition. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] [Figure 1] FIG. 1 is a schematic cross-sectional view illustrating a battery pack according to an exemplary embodiment. MODES FOR CARRYING OUT THE INVENTION

[0030] According to an embodiment of the present invention, there is provided a gap filler composition comprising a siloxane-based resin, a catalyst and a filler, and having improved curing properties. Further, according to an embodiment of the present invention, there is provided a battery pack using the gap filler composition.

[0031] <Gap Filler Composition> An exemplary gap filler composition may include a siloxane resin, a catalyst, and a filler.

[0032] The siloxane resin can be provided as a base component that provides the curability of the gap filler composition. According to exemplary embodiments, the siloxane resin may include a first siloxane resin and a second siloxane resin.

[0033] The first siloxane resin may be a siloxane resin containing crosslinkable end groups. According to an exemplary embodiment, the first siloxane resin may be a siloxane resin containing unsaturated end groups (e.g., vinyl groups) at both ends of the molecule.

[0034] For example, the first siloxane resin may contain a compound represented by the following chemical formula 1.

[0035] [ka]

[0036] In some embodiments, the viscosity of the first siloxane resin at 25°C may be 50 cps to 150,000 cps, preferably 70 cps to 1,500 cps, 100 cps to 1,500 cps, 200 cps to 1,500 cps, and more preferably 300 cps to 1,200 cps.

[0037] Within the viscosity range described above, the curing characteristics and curing speed described later can be more easily ensured, and appropriate coating characteristics and flowability of the gap filler composition can be ensured.

[0038] In some embodiments, the weight-average molecular weight of the first siloxane resin can be adjusted considering the viscosity within the range described above. For example, the weight-average molecular weight of the first siloxane resin may be 1,500 to 50,000, 10,000 to 50,000, preferably 10,000 to 30,000, and more preferably 10,000 to 25,000.

[0039] In chemical formula 1, n can be adjusted considering the viscosity range. For example, n may be a natural number in the range of 40-800, 80-800, 100-800, 130-700, or 150-700.

[0040] The content of the first siloxane resin in the total weight (e.g., solids) of the gap filler composition may be 1.5% to 13% by weight. In one embodiment, the content of the first siloxane resin may be 5% to 13% by weight, preferably 7% to 12% by weight, or 8% to 10% by weight. Within this content range, a gap filler with appropriate hardness and elasticity can be effectively formed.

[0041] The second siloxane resin may be a siloxane resin having a different structure from the first siloxane resin.

[0042] The second siloxane-based resin is included in the gap filler composition as a chain extender or chain modifier, and can be used to adjust the viscosity, flowability, crosslinkability, etc., of the entire composition.

[0043] According to an exemplary embodiment, the second siloxane resin may be a siloxane resin in which saturated groups (e.g., hydrogen atoms) are bonded to silicon atoms at both ends.

[0044] For example, the second siloxane resin may contain a compound represented by the following chemical formula 2.

[0045] [ka]

[0046] In some embodiments, the viscosity of the second siloxane resin at 25°C may be 10 cps to 1,500 cps, preferably 100 cps to 1,500 cps, 200 cps to 1,500 cps, and more preferably 300 cps to 1,200 cps.

[0047] The weight-average molecular weight of the second siloxane resin can be adjusted according to the viscosity range. For example, the weight-average molecular weight of the second siloxane resin may be 500 to 50,000, 10,000 to 50,000, preferably 10,000 to 30,000, and more preferably 10,000 to 25,000. Within the range of molecular weight and viscosity, the curing characteristics and curing speed described later can be more easily ensured, and appropriate coating characteristics and flowability of the gap filler composition can be ensured.

[0048] In chemical formula 2, m can be adjusted considering the range of molecular weight and viscosity. For example, m may be a natural number in the range of 10-700, 20-700, 30-700, 50-700, 100-700, or 130-700.

[0049] The content of the second siloxane resin in the total weight (e.g., solids) of the gap filler composition may be 0.5% to 10% by weight. In one embodiment, the content of the second siloxane resin may be 2% to 10% by weight, preferably 2% to 7% by weight, and more preferably 2% to 5% by weight. Within this content range, a gap filler with appropriate hardness and elasticity can be effectively formed.

[0050] According to exemplary embodiments, the content of the siloxane resin in the total weight (e.g., solids) of the gap filler composition may be 2% to 23% by weight. In one embodiment, the content of the siloxane resin may be 7% to 23% by weight, preferably 7% to 20% by weight, more preferably 10% to 15% by weight, or 10% to 14% by weight.

[0051] In some embodiments, the gap filler composition may further contain a crosslinking agent. The crosslinking agent may be a siloxane resin having a relatively low viscosity and in which methyl groups are bonded to silicon atoms at both ends. For example, the crosslinking agent may include a compound represented by chemical formula 3.

[0052] [ka]

[0053] In one embodiment, the viscosity of the crosslinking agent may be less than the viscosity of the second siloxane resin. In one embodiment, the viscosity of the crosslinking agent at 25°C may be less than 100 cps, and n in chemical formula 3 can be adjusted considering the viscosity range.

[0054] The crosslinking agent may be included in the crosslinking composition described later. The content of the crosslinking agent in the total weight of the gap filler composition may be 0.1% to 0.5% by weight.

[0055] The catalyst can be used as a modifier to promote the crosslinking and / or interaction of the siloxane resin in the gap filler composition and to obtain the curing properties and curing speed described later.

[0056] In some embodiments, the catalyst may include compounds or complexes of Pt(II), Pt(IV), and / or Pt(0). For example, the catalyst may include chloroplatinic acid, Ashby's catalyst, or Karstedt catalyst.

[0057] According to exemplary embodiments, the catalyst may include an organic-inorganic hybrid catalyst containing platinum and silicon.

[0058] The catalyst may contain a Pt atom and a Si2O group (-Si-O-Si-) within its molecule. For example, the silicon (Si) atom of the Si2O group may be bonded to a vinyl group, and the Pt atom may be coordinated or captured by the vinyl group.

[0059] According to exemplary embodiments, the weight ratio of platinum (Pt) to the weight of silicon (Si) atoms and oxygen (O) atoms in the catalyst may be 1.2 to 2.0, preferably 1.2 to 1.5, and more preferably 1.25 to 1.45.

[0060] By using catalysts within the aforementioned weight ratio range, the appropriate activity of the catalyst due to Pt atoms can be maintained. Therefore, the curing characteristics and curing speed of the gap filler composition described later can be easily achieved using the catalyst.

[0061] For example, the catalyst may contain units represented by the following chemical formula 4 within its molecule.

[0062] [ka]

[0063] In some embodiments, the content of the catalyst in the total weight of the composition may be 0.01% to 0.05% by weight. Within this range, an appropriate curing rate can be achieved while preventing an excessive increase in the hardness / elasticity of the gap filler.

[0064] The aforementioned filler can be included as a component that increases the thermal conductivity of the gap filler and improves the heat dissipation characteristics of the battery pack.

[0065] The filler may contain thermally conductive inorganic particles. Examples of thermally conductive inorganic particles include aluminum hydroxide (Al(OH)3), magnesium hydroxide (Mg(OH)2), calcium hydroxide (Ca(OH)2), hydromagnesite (Mg5(CO3)4(OH)2·4H2O), magnesia, alumina, AlN (aluminum nitride), BN (boron nitride), silicon nitride, SiC, ZnO, and BeO.

[0066] According to exemplary embodiments, the filler may include aluminum hydroxide (Al(OH)3) particles. The aluminum hydroxide particles have a relatively lower specific gravity compared to alumina particles, which can lower the overall specific gravity of the gap filler composition and improve its filling properties and flowability.

[0067] In some embodiments, the gap filler composition may not contain alumina particles. In one embodiment, the thermally conductive inorganic particles may consist substantially of aluminum hydroxide particles. For example, the thermally conductive inorganic particles may not contain alumina particles.

[0068] In some embodiments, the thermally conductive inorganic particles or aluminum hydroxide particles may be untreated particles. For example, the thermally conductive inorganic particles or aluminum hydroxide particles may be bare particles that have not been treated with alkyl or alkylsilane groups. Therefore, the specific gravity reduction effect achieved by using the aluminum hydroxide particles can be realized more effectively.

[0069] The thermally conductive inorganic particles may be included in the gap filler composition in the maximum possible amount (by weight). This makes it possible to sufficiently improve the thermal conductivity of the gap filler composition.

[0070] The content of the thermally conductive inorganic particles in the total weight of the composition may be 75% to 95% by weight. In some embodiments, the content of the thermally conductive inorganic particles may be 75% to 90% by weight, preferably 80% to 90% by weight, and more preferably 85% to 90% by weight.

[0071] According to exemplary embodiments, the filler may further include hollow particles. By adding the hollow particles, the specific gravity of the gap filler composition can be further reduced while maintaining or improving its thermal conductivity.

[0072] Examples of the aforementioned hollow particles include hollow organic particles such as acrylic particles (e.g., PMMA (poly(methylmethacrylate))), epoxy particles, nylon particles, styrene particles, and styrene / vinyl copolymer particles; and hollow inorganic particles such as silica particles, indium oxide particles, tin oxide particles, zirconium oxide particles, zinc oxide particles, and titania particles.

[0073] In a preferred embodiment, hollow inorganic particles can be used as the hollow particles, for example, hollow silica particles can be used.

[0074] In one embodiment, the hollow particles can be particles having a density in the range of 0.05 g / cc to 0.8 g / cc. By using hollow particles in this range, the specific gravity reduction effect can be fully realized. Preferably, the density of the hollow particles may be 0.1 g / cc to 0.8 g / cc, 0.1 g / cc to 0.5 g / cc, and more preferably 0.2 g / cc to 0.4 g / cc.

[0075] In one embodiment, the isostatic crushing strength of the hollow particles may be 100 psi to 50,000 psi, preferably 2,000 psi to 50,000 psi or more. This improves the resistance of the gap filler formed using the gap filler composition to external impacts.

[0076] In some embodiments, the content of the hollow particles in the total weight of the composition may be 0.1% to 5% by weight. Within this range, the specific gravity of the composition can be effectively reduced without excessively reducing the thermal conductivity of the gap filler composition.

[0077] Preferably, the content of the hollow particles in the total weight of the composition may be 0.5 to 4% by weight, more preferably 0.5 to 3% by weight, or 1% to 3% by weight.

[0078] An exemplary gap filler composition may further include an aminosilicone-based dispersant.

[0079] In some embodiments, the aminosilicone dispersant may include an aminosilicone oil containing siloxane units and amino groups. For example, the aminosilicone dispersant may include siloxane units and amino-containing groups.

[0080] For example, the aminosilicone-based dispersant may contain siloxane units represented by the following general formula 1, and may also contain amino-containing groups represented by the following general formula 2. The amino-containing groups may be bonded to silicon atoms.

[0081] [ka]

[0082] In general formula 1, R a and R bEach of these may be hydrogen, a C1-C5 alkyl group, or a group represented by general formula 2.

[0083] [ka]

[0084] In general formula 1, R c ALK1 may be hydrogen or a C1-C5 alkyl group. ALK1 and ALK2 may each independently be a C1-C6 alkylene group.

[0085] For example, a siloxane unit represented by general formula 1 may be included as a repeating unit of the aminosilicone-based dispersant. An amino-containing group represented by general formula 2 is present in at least one siloxane unit of the repeating siloxane unit. a or R b They may be combined as follows:

[0086] The aforementioned aminosilicone-based dispersant ensures sufficient dispersibility even when using thermally conductive inorganic particles that have not undergone surface treatment. This makes it possible to achieve uniform thermal conductivity overall while reducing the specific gravity of the composition.

[0087] Furthermore, dispersants containing siloxane units can stabilize the filler at the interface between the siloxane-based resin and the filler. This prevents aggregation of the filler, maintains the viscosity of the composition stably, and improves flowability.

[0088] In some embodiments, the dispersant does not need to contain a hydroxyl group or an epoxy group. This prevents side reactions between the filler and the siloxane resin caused by the hydroxyl group or epoxy group, and improves the dispersibility and thermal conductivity uniformity of the composition.

[0089] In some embodiments, the content of the aminosilicone-based dispersant in the total weight of the composition may be 0.1% to 3% by weight. In one embodiment, the content of the aminosilicone-based dispersant may be 0.1% to 0.5% by weight, preferably 0.2% to 0.4% by weight. Within this range, the dispersibility of aluminum hydroxide particles can be improved and an increase in the specific gravity of the composition can be prevented.

[0090] In some embodiments, the amine value, defined as the amount of 0.1N HCl titrant required to neutralize 10 g of the aminosilicone-based dispersant, may be 1 mg KOH / g to 80 mg KOH / g, preferably 10 mg KOH / g to 60 mg KOH / g, and more preferably 20 mg KOH / g to 50 mg KOH / g. Within this range, the aforementioned filler stabilization effect can be effectively achieved.

[0091] In some embodiments, the gap filler composition may further include additives to improve the conductivity and curability of the composition, to the extent that they do not inhibit the action of the siloxane resin, catalyst, and filler. Examples of such additives include flame retardants, surfactants, silane coupling agents, colorants (e.g., pigments), antioxidants, and plasticizers. These additives may be included in the composition as a residue or excess after removing the siloxane resin, catalyst, and filler.

[0092] For example, the flame retardant can be an organic flame retardant such as melamine cyanurate, or an inorganic flame retardant such as magnesium hydroxide. In one embodiment, a liquid type flame retardant (such as triethyl phosphate (TEP) or tris(1,3-chloro-2-propyl)phosphate (TCPP)) can also be used.

[0093] For example, the surfactants that can be used include polyethylene glycol, polypropylene glycol, oleic acid ethoxylate, alkylphenol ethoxylate, ethylene oxide, copolymers of propylene oxide and silicone polymers.

[0094] For example, examples of the silane coupling agent include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, 3-isocyanatetopropyltriethoxysilane, and γ-acetacetatetopropyltrimethoxysilane.

[0095] For example, phenolic compounds, quinone compounds, amine compounds, phosphorus compounds, phosphite compounds, thioether compounds, and the like can be used as the antioxidant.

[0096] For example, the plasticizers that can be used include tetraethylene glycol monobutyl ether (3,6,9,12-tetraoxahexadecanol), triethylene glycol monobutyl ether (3,6,9-trioxatridecanol), diethylene glycol monobutyl ether (2-(2-butoxyethoxy)ethanol), propylene glycol monobutyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether (1-methoxy-2-propanol), propylene glycol monomethyl ether acetate, polyethylene glycol, glycerin, and the like.

[0097] In exemplary embodiments, the specific gravity of the gap filler composition may be less than 3, preferably 2.5 or less. In some embodiments, the specific gravity of the gap filler composition may be 1.5 to 2, more preferably 1.5 to 1.9.

[0098] The aforementioned specific gravity is a value measured as a relative ratio based on the density of water at 1 atmosphere and 4°C.

[0099] Within the aforementioned specific gravity range, a gap filler can be obtained that achieves the desired heat dissipation characteristics and improves mechanical stability without increasing the weight of the battery pack.

[0100] The gap filler composition can be prepared as a two-component composition. For example, the gap filler composition can be produced by separately preparing a main component composition and a crosslinking composition, and then mixing the main component composition and the crosslinking composition.

[0101] According to embodiments of the present invention, the first siloxane resin described above may be included in both the main composition and the crosslinked composition.

[0102] According to exemplary embodiments, the main component composition may include the first siloxane resin, the catalyst, and the filler. The crosslinked composition may include the second siloxane resin, the crosslinking agent, and the filler.

[0103] For example, in the main component composition, the catalyst may be distributed in the first siloxane resin before the second siloxane resin is mixed. This allows the second siloxane resin to be introduced with crosslinking points distributed in the main component composition, thereby improving curing efficiency.

[0104] In some embodiments, the first siloxane resin may also be included in the crosslinked composition. The weight of the first siloxane resin included in the main composition may be greater than the weight of the first siloxane resin included in the crosslinked composition.

[0105] The filler may be divided and included in the main composition and the crosslinking composition. In one embodiment, the weight ratio of the amount of filler contained in the main composition to the amount of filler contained in the crosslinking composition may be 0.4 to 0.6, preferably 0.45 to 0.55. Within this ratio range, the filler is uniformly distributed, thereby improving the heat conduction efficiency.

[0106] As described above, the filler includes thermally conductive inorganic particles and hollow particles, and the aminosilicone-based dispersant can improve the dispersibility of untreated particles. The aminosilicone-based dispersant may also be included in the main composition and the crosslinking composition in separate parts.

[0107] <Battery Pack> Figure 1 is a schematic cross-sectional view showing a battery pack according to an exemplary embodiment.

[0108] Referring to Figure 1, the battery pack 100 includes a battery module 110 and a support plate 130, and may include a gap filler 120 formed in the battery module 110 and the support plate 130.

[0109] The battery module 110 may include a plurality of battery cells 112. Each battery cell 112 may include an electrode assembly comprising alternatingly stacked positive and negative electrodes. The positive and negative electrodes may be alternately stacked with a separator membrane in between. The positive electrode may contain a lithium metal oxide as the positive electrode active material, and the battery cell 112 can be provided as a lithium secondary battery.

[0110] Multiple battery cells 112 each include a positive lead and a negative lead, and the positive lead and the negative lead are joined together via a busbar to define a battery module 110.

[0111] The battery module 110 can be fixed onto the support plate 130. A gap filler 120 can be formed between the battery module 110 and the support plate 130 by applying and curing the gap filler composition according to the above embodiment.

[0112] The gap filler 120 allows the battery module 110 to be stably fixed onto the support plate 130. As described above, the gap filler 120 has stable curing characteristics as well as improved thermal conductivity characteristics.

[0113] According to exemplary embodiments, the gap filler composition has a low specific gravity and can maintain a target hardness range over a predetermined time period. Therefore, stable hardness characteristics can be maintained without reducing the overall efficiency of the electric vehicle manufacturing process or increasing the weight of the battery pack.

[0114] As a result, the battery module 110 has shock resistance and heat resistance to protect it even under high-temperature conditions, and sufficient heat dissipation characteristics can be provided.

[0115] The gap filler 120 can be provided as a thermal conductive layer. For example, the thermal conductivity of the gap filler 120 may be about 1.5 W / mK or higher. In one embodiment, the thermal conductivity of the gap filler 120 may be 1.5 W / mK to 4 W / mK, 1.5 W / mK to 3.5 W / mK, or 1.5 W / mK to 3 W / mK.

[0116] Within the aforementioned range, sufficient heat dissipation characteristics can be ensured without excessively increasing the specific gravity of the gap filler or gap filler composition.

[0117] For example, the thermal conductivity can be measured according to the ISO 22007-2 standard.

[0118] According to an exemplary embodiment, the height of the gap filler 120 on which the battery module 110 is placed may be 5.4 mm to 5.8 mm, preferably 5.4 mm to 5.7 mm. Within this range, sufficient support stability for the battery module 110 can be ensured, and sufficient thermal conductivity can be achieved. Furthermore, the formation of a gap between the battery module 110 and the gap filler 120 due to excessive hardening can be prevented.

[0119] The following are specific examples to aid in understanding the present invention. However, these examples are merely illustrative of the present invention and do not limit the scope of the attached claims. It will be obvious to those skilled in the art that various changes and modifications to the examples are possible within the scope of the present invention and the technical concept, and that such variations and modifications naturally fall within the scope of the attached claims.

[0120] Examples and Comparative Examples A gap filler composition was prepared based on the components and their content (parts by weight) shown in Table 1 below.

[0121] Specifically, the main component composition contained a first siloxane resin (vinyl-terminated siloxane resin) and a catalyst, while the crosslinked composition contained a first siloxane resin (vinyl-terminated siloxane resin) and a second siloxane resin (hydrogen-terminated siloxane resin). The first siloxane resin was divided and included in the main component composition and the crosslinked composition in a weight ratio of approximately 2:1. The crosslinked composition further contained a crosslinking agent having a hydrogen-terminated siloxane resin structure.

[0122] The thermally conductive inorganic particles, aminosilicone-based dispersant, and hollow particles were included in the main composition and the crosslinked composition, respectively, in a weight ratio of 1:1.

[0123] On the other hand, in Example 6, instead of aluminum hydroxide particles, alumina particles with an average particle size (D50) of approximately 60 μm and surface-treated with an alkylsilane agent (hexyltrimethoxysilane) were used.

[0124] The main component composition and the crosslinked composition were prepared by blending the components shown in Table 1 as described above, placing them in a paste mixer, mixing and stirring for 3 minutes at 600 rpm orbital / 500 rpm rotation, and then degassing under vacuum at 1000 rpm orbital / 100 rpm rotation for 10 minutes.

[0125] [Table 1]

[0126] The details of each component shown in Table 1 are as follows: A-1) Primary siloxane resin A polydimethylsiloxane resin with a viscosity of 270 cps, treated with vinyl groups at both ends (see Chemical Formula 1). B-1) Second siloxane resin A polydimethylsiloxane resin with a viscosity of 500 cps and hydrogen-treated ends (see Chemical Formula 2). C-1) Crosslinking agent A polydimethylsiloxane resin with a viscosity of 65 cps and hydrogen-treated ends (see Chemical Formula 3). D-1) Aminosilicone-based dispersants (see general formulas 1 and 2): Amine value 36 mg KOH / g D-2) Hydroxyl group-containing silicone-based dispersant (BYK 1799) F-1) Thermally conductive inorganic particles Aluminum hydroxide particles (D50: 5μm) F-2) Thermally conductive inorganic particles Alumina particles (D50: 60 μm) G-1) Hollow silica particles Density: 0.35 g / cc, Isostatic Crush Strength: 2,000 psi H-1) Catalyst Catalyst: Pt / Si2O bond catalyst (Pt / (Si+O) weight ratio: 1.35)

[0127] Experimental example (1) Measurement of specific gravity The main component compositions and crosslinking compositions of the examples and comparative examples were mixed in a 1:1 mass ratio using a two-component cartridge to prepare gap filler compositions. The specific gravity of the gap filler compositions was measured in accordance with Test Method A of ASTM D792. Specifically, in accordance with the aforementioned standards, the weight of the composition and the weight of the composition in water were measured, and then the specific gravity was calculated from the measured weight difference.

[0128] (2) Measurement of thermal conductivity The main component compositions and crosslinking compositions of the examples and comparative examples were mixed in a 1:1 mass ratio using a two-component cartridge and cured to form a resin layer. The thermal conductivity of the aforementioned resin layer was measured using a hot disk measuring device according to the ISO 22007-2 standard. Specifically, a resin layer measuring 20 mm in length and width and 6.0 mm in thickness was formed, and the average value of three measurements was calculated.

[0129] (3) Measurement of viscosity The main component compositions and crosslinking compositions of the examples and comparative examples were mixed in a 1:1 mass ratio using a two-component cartridge to prepare gap filler compositions. The change in viscosity of the gap filler compositions over time was measured using a viscoelasticity measuring instrument (Advanced Rheometric Expansion System) (Brookfield, DV2T Rheometer) (measurement conditions: 20 rpm / 25°C, Gap: 5 mm). The evaluation results are shown in Table 2 below.

[0130] [Table 2]

[0131] Referring to Tables 1 and 2, in the examples using aminosilicone-based dispersants and hollow particles, stable viscosity over time stability was obtained while maintaining a low specific gravity of 3 g / cc or less, preferably 1.5 g / cc to 1.9 g / cc, and a thermal conductivity in the range of 1.7 W / mK to 2.5 W / mK, preferably 1.9 W / mK to 2.5 W / mK.

[0132] In Examples 4 and 5, where the amount of aminosilicone-based dispersant was relatively small, viscosity stability was slightly lower compared to the other examples.

[0133] In Example 6, which used surface-treated alumina particles, the specific gravity of the composition increased slightly.

[0134] In Examples 7 and 8, where the content of hollow particles was slightly reduced or increased, the balance between improved specific gravity, viscosity stability, and thermal conductivity was slightly lower compared to the other examples.

[0135] In Comparative Examples 1 and 4, where a hydroxyl-silicone dispersant was used instead of an aminosilicone dispersant, viscosity stability was significantly reduced due to side reactions on the surface of thermally conductive inorganic particles.

[0136] In Comparative Example 2, where hollow particles were omitted, the specific gravity of the composition increased compared to Example 2, which used the same thermally conductive inorganic particles, exceeding 1.9.

[0137] Referring to Example 9, the content of thermally conductive inorganic particles was increased while the content of siloxane resin was decreased. In Example 9, the specific gravity and viscosity were relatively higher compared to the other examples.

Claims

1. Siloxane resins and A filler containing thermally conductive inorganic particles and hollow particles, Catalyst and A gap filler composition comprising an aminosilicone-based dispersant.

2. The gap filler composition according to claim 1, wherein the content of the aminosilicone-based dispersant in the total weight of the composition is 0.1% to 3% by weight.

3. The gap filler composition according to claim 1, wherein the thermally conductive inorganic particles include aluminum hydroxide particles.

4. The gap filler composition according to claim 3, wherein the aluminum hydroxide particles are particles that have not been surface-treated with an alkyl group or alkylsilane group.

5. The gap filler composition according to claim 3, wherein the content of the thermally conductive inorganic particles in the total weight of the composition is 75% by weight to 95% by weight.

6. The gap filler composition according to claim 1, wherein the hollow particles include hollow silica particles.

7. The gap filler composition according to claim 6, wherein the density of the hollow particles is 0.1 g / cc to 0.8 g / cc.

8. The gap filler composition according to claim 1, wherein the content of the hollow particles in the total weight of the composition is 0.1% by weight to 5% by weight.

9. The gap filler composition according to claim 1, wherein the siloxane resin comprises a first siloxane resin having an unsaturated end group and a second siloxane resin having a saturated end group.

10. The gap filler composition according to claim 9, wherein the first siloxane resin comprises a siloxane resin having vinyl groups at both ends, and the second siloxane resin comprises a siloxane resin in which hydrogen atoms are bonded to silicon atoms at both ends.

11. The gap filler composition according to claim 10, further comprising a crosslinking agent containing a siloxane resin in which methyl groups are bonded to silicon atoms at both ends.

12. The gap filler composition according to claim 9, wherein the content of the siloxane resin in the total weight of the composition is 2% to 23% by weight.

13. The gap filler composition according to claim 1, having a specific gravity of less than 3.

14. The gap filler composition according to claim 1, having a specific gravity of 1.5 to 1.

9.

15. Multiple battery modules, Support plate and A battery pack comprising a gap filler formed between the battery module and the support plate using the gap filler composition described in claim 1.

Images