Gap filler composition and battery pack

Abstract

A gap filler composition according to embodiments of the present invention comprises: a siloxane-based resin; a filler including thermally conductive inorganic particles and hollow particles; a catalyst; and an amino-silicone-based dispersant. A gap filler composition is provided that maintains thermal conductivity by utilizing an amino-silicone-based dispersant and hollow particles and has low specific gravity and improved viscosity stability. A battery pack utilizing the gap filler composition is provided.

Description

Gap filler composition and battery pack

[0001] The present invention relates to a gap filler composition and a battery pack. More particularly, the present invention relates to a gap filler composition comprising a siloxane-based resin and a battery pack comprising a gap filler formed using the same.

[0002]

[0003] Secondary batteries, which can be repeatedly charged and discharged, are widely used as power sources for portable electronic devices such as cell phones and laptops. For example, lithium secondary batteries boast high operating voltage, energy density, and rate characteristics, and are recently being utilized as power sources for electric vehicles.

[0004] For example, a battery cell is defined by a lithium secondary battery, and a plurality of battery cells are assembled to form a battery module. The battery modules can be assembled to form a high-capacity / high-output battery pack applicable to electric vehicles.

[0005] To apply the battery pack to a vehicle such as an electric vehicle, the battery pack can be secured to a battery support plate and a gap filler composition can be used to secure the battery pack.

[0006] The above gap filler composition application process can be incorporated into the overall electric vehicle production platform. Therefore, to maintain process efficiency and reliability, a gap filler composition that cures within a predetermined time and provides desired properties may be required.

[0007] In order to dissipate heat generated by repeated charging and discharging of the battery pack, it is necessary to design a composition capable of forming a gap filler having improved thermal conductivity, appropriate absorbency and / or elasticity against external impact, and low weight and / or specific gravity.

[0008] For example, Korean Patent Publication No. 10-2402503 discloses a battery pack structure including a battery module and a gap filler.

[0009]

[0010] An object of the present invention is to provide a gap filler composition that provides improved thermal and mechanical properties.

[0011] One object of the present invention is to provide a battery pack including a gap filler formed of the gap filler composition.

[0012]

[0013] 1. A gap filler composition comprising a siloxane-based resin; a filler including thermally conductive inorganic particles and hollow particles; a catalyst; and an amino-silicone-based dispersant.

[0014] 2. In the above 1, the content of the amino-silicone dispersant among the total weight of the composition is 0.1 wt% to 3 wt%, gap filler composition.

[0015] 3. A gap filler composition in the above 1, wherein the thermally conductive inorganic particles include aluminum hydroxide particles.

[0016] 4. A gap filler composition in the above 3, wherein the aluminum hydroxide particles are particles that are not surface-treated with an alkyl group or an alkylsilane group.

[0017] 5. In the above 3, the content of the thermally conductive inorganic particles in the total weight of the composition is 75 wt% to 95 wt%, a gap filler composition,

[0018] 6. In the above 1, the gap filler composition comprises hollow silica particles.

[0019] 7. A gap filler composition in the above 6, wherein the density of the hollow particles is 0.1 g / cc to 0.8 g / cc.

[0020] 8. A gap filler composition in which the content of the hollow particles in the total weight of the composition in 1 above is 0.1 wt% to 5 wt%.

[0021] 9. A gap filler composition in the above 1, wherein the siloxane-based resin comprises a first siloxane-based resin including an unsaturated terminal group and a second siloxane-based resin including a saturated terminal group.

[0022] 10. A gap filler composition in the above 9, wherein the first siloxane-based resin includes a siloxane-based resin having vinyl groups at both terminals, and the second siloxane-based resin includes a siloxane-based resin having hydrogen bonded to silicon atoms at both terminals.

[0023] 11. A gap filler composition further comprising a crosslinking agent having a methyl group bonded to silicon atoms at both terminals in the above 10.

[0024] 12. In the above 9, the content of the siloxane-based resin among the total weight of the composition is 2 wt% to 23 wt%, gap filler composition.

[0025] 13. A gap filler composition having a specific gravity of less than 3 in the above 1.

[0026] 14. A gap filler composition having a specific gravity of 1.5 to 1.9 in the above 1.

[0027] 15. A battery pack comprising a plurality of battery modules; a support plate; and a gap filler formed between the battery modules and the support plate using a gap filler composition according to the embodiments described above.

[0028]

[0029] Gap filler compositions according to exemplary embodiments of the present invention may include hollow particles as fillers. Furthermore, the fillers may include thermally conductive inorganic particles, and the thermally conductive inorganic particles may include aluminum hydroxide particles. In some embodiments, untreated aluminum hydroxide particles may be used.

[0030] The specific gravity of the gap filler composition is reduced by the hollow particles, and the specific gravity of the gap filler composition can be further reduced while maintaining thermal conductivity by the thermally conductive inorganic particles.

[0031] Therefore, the above gap filler composition can be applied to a vehicle battery pack to reduce the weight of the battery pack and promote rapid heat dissipation even when the temperature increases due to repeated charging / discharging of the battery pack.

[0032] According to exemplary embodiments, the gap filler composition may include an amino-silicone-based dispersant. The amino-silicone-based dispersant may increase dispersibility between the filler and the siloxane-based resin, thereby enhancing the storage stability of the composition.

[0033]

[0034] FIG. 1 is a schematic cross-sectional view illustrating a battery pack according to exemplary embodiments.

[0035]

[0036] According to embodiments of the present invention, a gap filler composition comprising a siloxane-based resin, a catalyst, and a filler, and having improved curing properties is provided. Furthermore, according to embodiments of the present invention, a battery pack using the gap filler composition is provided.

[0037] Gap filler composition

[0038] A gap filler composition according to exemplary embodiments may include a siloxane-based resin, a catalyst, and a filler.

[0039] The above siloxane-based resin may be provided as a base component that provides curability to the gap filler composition. According to exemplary embodiments, the siloxane-based resin may include a first siloxane-based resin and a second siloxane-based resin.

[0040] The first siloxane-based resin may be a siloxane-based resin containing crosslinkable terminal groups. According to exemplary embodiments, the first siloxane-based resin may be a siloxane-based resin containing unsaturated terminal groups (e.g., vinyl groups) at both ends of the molecule.

[0041] For example, the first siloxane resin may include a compound represented by the following chemical formula 1.

[0042] [Chemical Formula 1]

[0043]

[0044] In some embodiments, 25 of the first siloxane resin o At C, the viscosity 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, more preferably 300 cps to 1,200 cps.

[0045] Within the above viscosity range, the curing characteristics and curing speed described below can be more easily secured, and appropriate application characteristics and flowability of the gap filler composition can be secured.

[0046] In some embodiments, the weight average molecular weight of the first siloxane-based resin may be adjusted in consideration of the viscosity within the above-described range. For example, the weight average molecular weight of the first siloxane-based 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.

[0047] In chemical formula 1, n can be adjusted in consideration of the viscosity range. For example, n can be a natural number in the range of 40 to 800, 80 to 800, 100 to 800, 130 to 700, or 150 to 700.

[0048] The content of the first siloxane-based resin among the total weight of the gap filler composition (e.g., solid content) may be 1.5 wt% to 13 wt%. In one embodiment, the content of the first siloxane-based resin may be 5 wt% to 13 wt%, preferably 7 wt% to 12 wt%, or 8 wt% to 10 wt%. Within the above content range, a gap filler having appropriate hardness and elasticity can be effectively formed.

[0049] The above second siloxane-based resin may be a siloxane-based resin having a different structure from the above first siloxane-based resin.

[0050] The above second siloxane resin is included as a chain extender or chain regulator of the gap filler composition, and can control the overall viscosity, flowability, crosslinking property, etc. of the composition.

[0051] According to exemplary embodiments, the second siloxane-based resin may be a siloxane-based resin in which a saturating group (e.g., a hydrogen atom) is bonded to silicon atoms at both terminals.

[0052] For example, the second siloxane resin may include a compound represented by the following chemical formula 2.

[0053] [Chemical Formula 2]

[0054]

[0055] In some embodiments, 25 of the second siloxane resin o At C, the viscosity may be from 10 cps to 1,500 cps, preferably from 100 cps to 1,500 cps, from 200 cps to 1,500 cps, and more preferably from 300 cps to 1,200 cps.

[0056] The weight average molecular weight of the second siloxane-based resin can be adjusted according to the viscosity range. For example, the weight average molecular weight of the second siloxane-based resin can 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 molecular weight and viscosity ranges, the curing characteristics and curing speed described below can be more easily secured, and appropriate application characteristics and flowability of the gap filler composition can be secured.

[0057] In Chemical Formula 2, m can be adjusted in consideration of the molecular weight and viscosity ranges. For example, m can be a natural number in the range of 10 to 700, 20 to 700, 30 to 700, 50 to 700, 100 to 700, or 130 to 700.

[0058] The content of the second siloxane-based resin among the total weight of the gap filler composition (e.g., solid content) may be 0.5 wt% to 10 wt%. In one embodiment, the content of the second siloxane-based resin may be 2 wt% to 10 wt%, preferably 2 wt% to 7 wt%, and more preferably 2 wt% to 5 wt%. Within the above content range, a gap filler having appropriate hardness and elasticity can be effectively formed.

[0059] According to exemplary embodiments, the content of the siloxane-based resin in the total weight (e.g., solid content) of the gap filler composition may be from 2 wt% to 23 wt%. In one embodiment, the content of the siloxane-based resin may be from 7 wt% to 23 wt%, preferably from 7 wt% to 20 wt%, more preferably from 10 wt% to 15 wt%, or from 10 wt% to 14 wt%.

[0060] In some embodiments, the gap filler composition may further include a crosslinking agent. The crosslinking agent may be a siloxane-based resin having relatively low viscosity and having methyl groups bonded to silicon atoms at both ends. For example, the crosslinking agent may include a compound represented by Chemical Formula 3.

[0061] [Chemical Formula 3]

[0062]

[0063] In one embodiment, the viscosity of the crosslinking agent may be less than the viscosity of the second siloxane-based resin. In one embodiment, the viscosity of the crosslinking agent may be 25 o In C, the viscosity can be less than 100 cps, and n in chemical formula 3 can be adjusted considering the above viscosity range.

[0064] A crosslinking agent may be included in the crosslinking composition described below. The content of the crosslinking agent in the total weight of the gap filler composition may be 0.1 wt% to 0.5 wt%.

[0065] The above catalyst can be used as a regulator for obtaining curing characteristics and curing speed described below by promoting crosslinking and / or interaction of the siloxane resin of the gap filler composition.

[0066] In some embodiments, the catalyst may comprise a compound or complex of Pt(II), Pt(IV), and / or Pt(0). For example, the catalyst may comprise chloroplatinic acid, Ashby's catalyst, or Karstedt catalyst.

[0067] According to exemplary embodiments, the catalyst may comprise an organic-inorganic hybrid catalyst containing platinum and silicon.

[0068] The catalyst may contain Pt atoms and Si2O groups (-Si-O-Si-) within the molecule. For example, silicon (Si) atoms of the Si2O group may be bonded to vinyl groups, and Pt atoms may be coordinated or captured by the vinyl groups.

[0069] According to exemplary embodiments, the weight ratio of platinum (Pt) to the weight of silicon (Si) atoms and oxygen atoms (O) in the catalyst may be 1.2 to 2.0, preferably 1.2 to 1.5, and more preferably 1.25 to 1.45.

[0070] By using a catalyst within the above weight ratio range, appropriate catalyst activity can be maintained through Pt atoms. Accordingly, the curing characteristics and curing speed of the gap filler composition described below can be easily achieved using the catalyst.

[0071] For example, the catalyst may include a unit represented by the following chemical formula 4 within the molecule.

[0072] [Chemical Formula 4]

[0073] Ptㆍ[(CH2=CH(CH3)2Si)O]

[0074] In some embodiments, the content of the catalyst may be 0.01 wt% to 0.05 wt% of the total weight of the composition. Within this range, an appropriate curing speed can be achieved while preventing excessive hardness / elasticity increase of the gap filler.

[0075] The above filler may be included as a component that increases the thermal conductivity of the gap filler and thus improves the heat dissipation characteristics of the battery pack.

[0076] The above filler may include thermally conductive inorganic particles. Examples of the 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, aluminum nitride (AlN), boron nitride (BN), silicon nitride, SiC, ZnO, BeO, etc.

[0077] According to exemplary embodiments, the filler may include aluminum hydroxide (Al(OH)3) particles. The aluminum hydroxide particles have a relatively low specific gravity compared to alumina particles, and can lower the overall specific gravity of the gap filler composition and improve filling properties and flowability.

[0078] In some embodiments, the gap filler composition may not include alumina particles. In one embodiment, the thermally conductive inorganic particles may be substantially composed of aluminum hydroxide particles. For example, the thermally conductive inorganic particles may not include alumina particles.

[0079] In some embodiments, the thermally conductive inorganic particles or aluminum hydroxide particles may be unsurface-treated particles. For example, the thermally conductive inorganic particles or aluminum hydroxide particles may be bare particles that have not been surface-treated with alkyl or alkylsilane groups. Therefore, the specific gravity reduction effect resulting from the use of the aluminum hydroxide particles can be more effectively realized.

[0080] The above thermally conductive inorganic particles can be included in the largest amount (weight %) in the gap filler composition. Therefore, the thermal conductivity properties of the gap filler composition can be sufficiently increased.

[0081] The content of the thermally conductive inorganic particles in the total weight of the composition may be 75 wt% to 95 wt%. In some embodiments, the content of the thermally conductive inorganic particles may be 75 wt% to 90 wt%, preferably 80 wt% to 90 wt%, and more preferably 85 wt% to 90 wt%.

[0082] According to exemplary embodiments, the filler may further include hollow particles. The hollow particles may be added to further reduce the specific gravity of the gap filler composition while maintaining or increasing thermal conductivity.

[0083] Examples of the hollow particles include hollow organic particles such as acrylic particles such as PMMA (poly(methylmethacrylate)), epoxy particles, nylon particles, styrene particles, 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.

[0084] In a preferred embodiment, hollow inorganic particles may be used as the hollow particles, for example, hollow silica particles may be used.

[0085] In one embodiment, particles having a density in the range of 0.05 g / cc to 0.8 g / cc may be used as the hollow particles. Within this range, the effect of reducing specific gravity can be sufficiently achieved by employing the hollow particles. 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.

[0086] In one embodiment, the isostatic crush strength of the hollow particles may be 100 psi to 50,000 psi, preferably 2,000 psi to 50,000 psi or more. Accordingly, the strength of a gap filler formed using the gap filler composition against external impact can be enhanced.

[0087] In some embodiments, the content of the hollow particles may be 0.1 wt% to 5 wt% of the total weight of the composition. Within this range, the specific gravity of the gap filler composition can be effectively reduced without excessively lowering the thermal conductivity of the composition.

[0088] Preferably, the content of the hollow particles may be 0.5 to 4 wt%, more preferably 0.5 to 3 wt%, or 1 to 3 wt% of the total weight of the composition.

[0089] The gap filler composition according to exemplary embodiments may further comprise an amino-silicone based dispersant.

[0090] In some embodiments, the amino-silicone-based dispersant may include an amino silicone oil containing siloxane units and amino groups. For example, the amino-silicone-based dispersant may include siloxane units and amino-containing groups.

[0091] For example, the amino-silicone dispersant may include a siloxane unit represented by the following general formula 1 and an amino-containing group represented by the following general formula 2. The amino-containing group may be bonded to a silicon atom.

[0092] [General Formula 1]

[0093]

[0094] In general formula 1, R a and R b Each can be hydrogen, a C1-C5 alkyl group, or any one of the groups represented by the general formula 2.

[0095] [General Formula 2]

[0096] -ALK1-NH-ALK2-NH-R c

[0097] General formula 1, R c may be hydrogen or a C1-C5 alkyl group. ALK1 and ALK2 may each independently be a C1-C6 alkylene group.

[0098] For example, a siloxane unit represented by the general formula 1 may be included as a repeating unit of the amino-silicone dispersant. R of at least one siloxane unit among the siloxane units in which an amino-containing group represented by the general formula 2 is repeated a or R b can be combined as

[0099] Even when thermally conductive inorganic particles that have not been surface-treated are used, sufficient dispersibility can be secured through the amino-silicone dispersant described above. Therefore, uniform thermal conductivity can be achieved overall while reducing the specific gravity of the composition.

[0100] Additionally, a dispersant containing siloxane units can stabilize the filler at the interface between the siloxane-based resin and the filler described above. Therefore, it can prevent agglomeration of the filler, maintain a stable viscosity of the composition, and improve flowability.

[0101] In some embodiments, a dispersant containing a hydroxyl group or an epoxy group may not be used as the dispersant. Accordingly, side reactions between the filler and the siloxane resin due to the hydroxyl group or epoxy group can be prevented, and the dispersibility and thermal conductivity uniformity of the composition can be improved.

[0102] In some embodiments, the content of the amino-silicone-based dispersant may be 0.1 wt% to 3 wt% of the total weight of the composition. In one embodiment, the content of the amino-silicone-based dispersant may be 0.1 wt% to 0.5 wt%, preferably 0.2 wt% to 0.4 wt%. Within this range, the dispersibility of the aluminum hydroxide particles can be improved and the specific gravity of the composition can be prevented from increasing.

[0103] In some embodiments, the amine value, defined as the amount of 0.1 N HCl titrant required to neutralize 10 g of the amino-silicone-based dispersant, may be 1 mgKOH / g to 80 mgKOH / g, preferably 10 mgKOH / g to 60 mgKOH / g, and more preferably 20 mgKOH / g to 50 mgKOH / g. Within this range, the filler stabilization effect described above can be effectively implemented.

[0104] In some embodiments, the gap filler composition may further include additives to enhance the conductivity and curability of the composition within a range that does not inhibit the actions of the siloxane-based resin, the catalyst, and the filler described above. For example, the additives may include flame retardants, surfactants, silane coupling agents, colorants (e.g., pigments), antioxidants, plasticizers, and the like. The additives may be included in the composition as a remainder or extra amount, excluding the siloxane-based resin, catalyst, and filler described above.

[0105] For example, as the flame retardant, an organic flame retardant such as melamine cyanurate, an inorganic flame retardant such as magnesium hydroxide, etc. may be used. In one embodiment, a liquid type flame retardant material (such as triethyl phosphate (TEP) or tris(1,3-chloro-2-propyl)phosphate (TCPP)) may be used.

[0106] For example, polyethylene glycol, polypropylene glycol, oleic acid ethoxylate, alkylphenol ethoxylate, copolymers of ethylene oxide and propylene oxide, silicone polymers, etc. can be used as the surfactant.

[0107] For example, as examples of the silane coupling agent, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, 3-mercaptopropyl trimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, 3-isocyanatepropyltriethoxysilane, γ-acetoacetatepropyltrimethoxysilane, etc. can be used.

[0108] For example, phenol compounds, quinone compounds, amine compounds, phosphorus compounds, phosphite compounds, thioether compounds, etc. can be used as the antioxidants.

[0109] For example, as the plasticizer, 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, etc. can be used.

[0110] In exemplary embodiments, the specific gravity of the gap filler composition may be less than 3, preferably less than 2.5. In some embodiments, the specific gravity of the gap filler composition may be from 1.5 to 2, more preferably from 1.5 to 1.9.

[0111] The above specific gravity is 4 under 1 atm. oC is a numerical value measured as a relative ratio based on the density of water.

[0112] A gap filler having desired heat dissipation characteristics and improved mechanical stability can be obtained without increasing the weight of the battery pack within the above specific gravity range.

[0113] The gap filler composition may be prepared as a two-component composition. For example, the gap filler composition may be prepared by separately preparing a main composition and a crosslinking composition, and then mixing the main composition and the crosslinking composition.

[0114] According to embodiments of the present invention, the above-described first siloxane resin may be commonly included in the subject composition and the crosslinking composition.

[0115] According to exemplary embodiments, the subject composition may include the first siloxane-based resin, the catalyst, and the filler. The crosslinking composition may include the second siloxane-based resin, the crosslinking agent, and the filler.

[0116] For example, in the above-described subject composition, the second siloxane-based resin may be mixed while the catalyst is distributed in the first siloxane-based resin. Accordingly, since the second siloxane-based resin is introduced while the crosslinking points are distributed in the subject composition, curing efficiency may be enhanced.

[0117] In some embodiments, the first siloxane-based resin may also be included in the crosslinking composition. The weight of the first siloxane-based resin included in the subject composition may be greater than the weight of the first siloxane-based resin included in the crosslinking composition.

[0118] 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 the filler included in the main composition to the amount of the filler included in the crosslinking composition may be 0.4 to 0.6, preferably 0.45 to 0.55. Within this ratio range, the filler may be uniformly distributed, thereby enhancing heat conduction efficiency.

[0119] As described above, the filler includes thermally conductive inorganic particles and hollow particles, and the amino-silicon-based dispersant can improve the dispersibility of the unsurface-treated particles. The amino-silicon-based dispersant can also be separately included in the subject composition and the crosslinking composition.

[0120] Battery Pack

[0121] FIG. 1 is a schematic cross-sectional view illustrating a battery pack according to exemplary embodiments.

[0122] Referring to FIG. 1, a battery pack (100) includes a battery module (110) and a support plate (130), and may include a gap filler (120) formed on the battery module (110) and the support plate (130).

[0123] The battery module (110) may include a plurality of battery cells (112). Each of the battery cells (112) may include an electrode assembly including a positive electrode and a negative electrode that are alternately and repeatedly stacked. The positive electrode and the negative electrode may be alternately and repeatedly stacked with a separator between them. The positive electrode includes lithium metal oxide as a positive electrode active material, and the battery cell (112) may be provided as a lithium secondary battery.

[0124] A plurality of battery cells (112) each include a positive lead and a negative lead, and the positive leads and the negative leads can be joined to each other via a bus bar to define a battery module (110).

[0125] The battery module (110) can be fixed on the support plate (130). A gap filler composition according to the above-described embodiments can be applied and cured between the battery module (110) and the support plate (130) to form a gap filler (120).

[0126] The battery module (110) can be stably fixed on the support plate (130) by the gap filler (120). As described above, the gap filler (120) has stable curing characteristics and can have improved thermal conductivity characteristics.

[0127] 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 compromising the overall electric vehicle process efficiency or increasing the weight of the battery pack.

[0128] Therefore, it has impact resistance and heat resistance for protecting the battery module (110) even under high temperature conditions, and can provide sufficient heat dissipation characteristics.

[0129] The gap filler (120) may be provided as a thermally conductive layer. For example, the thermal conductivity of the gap filler (120) may be about 1.5 W / mK or more. 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.

[0130] Within the above range, sufficient heat dissipation properties can be secured without excessively increasing the specific gravity of the gap filler or gap filler composition.

[0131] For example, the thermal conductivity can be measured according to ISO 22007-2 standard.

[0132] According to exemplary embodiments, the height of the gap filler (120) on which the battery module (110) is mounted 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) is provided, and sufficient thermal conductivity characteristics can be achieved. In addition, the occurrence of a gap between the battery module (110) and the gap filler (120) due to excessive curing can be prevented.

[0133] Hereinafter, experimental examples including specific examples and comparative examples are presented to help understand the present invention, but these are only illustrative of the present invention and do not limit the scope of the appended claims. It is obvious to those skilled in the art that various changes and modifications to the examples are possible within the scope and technical idea of ​​the present invention, and it is natural that such changes and modifications fall within the scope of the appended claims.

[0134] Examples and Comparative Examples

[0135] A gap filler composition was prepared using the ingredients and contents (parts by weight) described in Table 1 below.

[0136] Specifically, the subject composition included a first siloxane-based resin (vinyl-terminated siloxane resin) and a catalyst, and the crosslinking composition included a first siloxane-based resin (vinyl-terminated siloxane resin) and a second siloxane-based resin (hydrogen-terminated siloxane resin). The first siloxane-based resin was divided and included in the subject composition and the crosslinking composition at a weight ratio of about 2:1. The crosslinking composition further included a crosslinking agent having a hydrogen-terminated siloxane resin structure.

[0137] Thermally conductive inorganic particles, amino-silicone-based dispersant and hollow particles were each divided and included in the main composition and crosslinked composition at a weight ratio of 1:1.

[0138] Meanwhile, in Example 6, alumina particles having an average particle diameter (D50) of approximately 60 μm and surface-treated with an alkylsilane agent (hexyltrimethoxysilane) were used instead of aluminum hydroxide particles.

[0139] The subject composition and the crosslinking composition were prepared by including the components of Table 1 as described above, placing them in a paste mixer, mixing and stirring them at 600 rpm / 500 rpm for 3 minutes, and then defoaming them in a vacuum at 1000 rpm / 100 rpm for 10 minutes.

[0140] First siloxane resin (A-1) Second siloxane resin (B-1) Crosslinking agent (C-1) Dispersing agent Thermally conductive inorganic particle (F-1) Hollow particle (G-1) Catalyst (H-1) D-1 D-2 Example 1 1.5 9 5.3 3 0.5 0.2 4 0.0 0 8 11.3 0.0 4 Example 2 8.3 8 3.1 2 0.6 0.2 4 0.0 0 8 5 2.6 0.0 4 Example 3 6.2 8 0.7 2 0.3 0.0 0 9 0 2.6 0.0 4 Example 4 9.5 0 3.6 5 0.3 0.1 8 0.0 0 8 5 1.3 0 .07 Example 58.884.120.300.360.00851.300.04 Example 69.763.440.220.240.0085(F-2)1.300.04 Example 79.763.440.220.240.0085.900.400.04 Example 89.763.440.220.240.0082.803.500.04 Example 92.000.500.100.360.00952.000.04Comparative Example 18.822.900.260.000.2686.201.500.06Comparative Example 29.924.000.800.240.00850.000.04Comparative Example 38.813.250.300.000.00852.600.04Comparative Example 48.123.640.300.000.30852.600.04

[0141] The specific ingredients listed in Table 1 are as follows.

[0142] A-1) First siloxane resin

[0143] Polydimethylsiloxane resin with a viscosity of 270 cps and vinyl groups at both ends (see Chemical Formula 1)

[0144] B-1) Second siloxane resin

[0145] Polydimethylsiloxane resin with a viscosity of 500 cps and hydrogenated at both ends (see Chemical Formula 2)

[0146] C-1) Crosslinking agent

[0147] Polydimethylsiloxane resin hydrogenated at both ends with a viscosity of 65 cps (see Chemical Formula 3)

[0148] D-1) Amino-silicone dispersant (see general formulas 1 and 2): amine value 36 mgKOH / g

[0149] D-2) Hydroxyl group-containing silicone dispersant (BYK 1799)

[0150] F-1) Thermally conductive inorganic particles

[0151] Aluminum hydroxide particles (D50: 5㎛)

[0152] F-2) Thermally conductive inorganic particles

[0153] Alumina particles (D50: 60㎛)

[0154] G-1) Hollow silica particles

[0155] Density 0.35g / cc, Isostatic Crush Strength: 2,000 psi

[0156] H-1) Catalyst

[0157] Catalyst: Pt / Si2O combined catalyst (Pt / (Si+O) weight ratio: 1.35)

[0158]

[0159] Experimental example

[0160] (1) Specific gravity measurement

[0161] The subject composition and crosslinking composition of the examples and comparative examples were mixed at a mass ratio of 1:1 using a two-component cartridge to prepare a gap filler composition. The specific gravity of the gap filler composition was measured according to Test Method A of ASTM D792.

[0162] Specifically, the weight of the composition and the weight of the composition in water were measured according to the above specifications, and the specific gravity was calculated through the difference in the measured weights.

[0163] (2) Thermal conductivity measurement

[0164] The subject composition and crosslinking composition of the examples and comparative examples were mixed at a mass ratio of 1:1 using a two-component cartridge and cured to form a resin layer.

[0165] The thermal conductivity of the above resin layer was measured using a hot disk measuring device according to the ISO 22007-2 standard. Specifically, a numerical layer measuring 20 mm in length and width and 6.0 mm in thickness was formed, and the average value was calculated after a total of three measurements.

[0166] (3) Viscosity measurement

[0167] The subject composition and crosslinking composition of the examples and comparative examples were mixed at a mass ratio of 1:1 using a two-component cartridge to prepare a gap filler composition. The viscosity of the gap filler composition over time was measured using a viscoelasticity measuring instrument (Advanced Rheometic Expansion System) (Brookfield, DV2T Rheometer). (Measurement conditions: 20 rpm / 25°C, Gap 5 mm).

[0168] The evaluation results are shown in Table 2 below.

[0169] Specific gravity (g / cc)Thermal conductivity (W / mK)Viscosity (mPa·s)Day of manufacture1 day2 days3 days4 daysExample 11.781.70285301326330329Example 21.772.10631663673675680Example 31.872.307939481,1001,2501,380Example 41 .852.20697788802855905Example 51.862.19449498490549552Example 62.502.60675708752779768Example 72.102.20250266270273765Example 81.601.728919341,0231,1231,256Example 92.002.5011591,2621,3011,3431,388Comparative Example 11.882.116769561,3401,7951,956Comparative Example 21.972.27404458460463458Comparative Example 31.872.229461,2801,5401,8892,035Comparative Example 41.882.137229451,2581,4971,759

[0170] Referring to Tables 1 and 2, in examples in which amino-silicone-based dispersants and hollow particles were used, stable viscosity stability was provided 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.

[0171] In Examples 4 and 5, where the amount of amino-silicone dispersant was relatively low, the viscosity stability was somewhat lower than in the other examples.

[0172] In Example 6, where surface-treated alumina particles were used, the specific gravity of the composition increased somewhat.

[0173] In Examples 7 and 8, where the content of hollow particles was slightly reduced or increased, the balance of low specific gravity, viscosity stability, and improved thermal conductivity was somewhat lowered compared to other examples.

[0174] In Comparative Examples 1 and 4, where a hydroxyl-silicone-based dispersant was used instead of an amino-silicone-based dispersant, viscosity stability was significantly reduced due to side reactions with the surface of the thermally conductive inorganic particles.

[0175] In Comparative Example 2, where hollow particles were omitted, the specific gravity of the composition increased to exceed 1.9 compared to Example 2, where thermally conductive inorganic particles having the same specific gravity were used.

[0176] Referring to Example 9, the content of the siloxane resin decreased as the content of the thermally conductive inorganic particles increased. In Example 9, the specific gravity and viscosity increased relatively compared to the other examples.

Claims

1. Siloxane resin; A filler comprising thermally conductive inorganic particles and hollow particles; catalyst; and A gap filler composition comprising an amino-silicone dispersant.

2. A gap filler composition according to claim 1, wherein the content of the amino-silicone dispersant in the total weight of the composition is 0.1 wt% to 3 wt%.

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

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

5. In claim 3, a gap filler composition in which the content of the thermally conductive inorganic particles in the total weight of the composition is 75 wt% to 95 wt%, 6. A gap filler composition according to claim 1, wherein the hollow particles include hollow silica particles.

7. A 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. A gap filler composition according to claim 1, wherein the content of the hollow particles in the total weight of the composition is 0.1 wt% to 5 wt%.

9. A gap filler composition according to claim 1, wherein the siloxane-based resin comprises a first siloxane-based resin including an unsaturated terminal group and a second siloxane-based resin including a saturated terminal group.

10. A gap filler composition according to claim 9, wherein the first siloxane-based resin includes a siloxane-based resin having vinyl groups at both terminals, and the second siloxane-based resin includes a siloxane-based resin having hydrogen atoms bonded to silicon atoms at both terminals.

11. A gap filler composition according to claim 10, further comprising a crosslinking agent comprising a siloxane resin having methyl groups bonded to silicon atoms at both terminals.

12. In claim 9, the content of the siloxane-based resin in the total weight of the composition is 2 wt% to 23 wt%, gap filler composition.

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

14. A 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 using the gap filler composition of claim 1 between the battery modules and the support plate.

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