Resin composition

Abstract

The present application relates to a resin composition, a method for producing the same, and uses thereof. The present application can provide a resin composition that has excellent thixotropy and one or more properties selected from thermal conductivity, adhesion, insulation, tensile properties, hardness, and flame retardancy, as well as a method for producing the same, and uses thereof.

Description

Technical Field

[0001] Cross-reference to Related Applications This application claims the benefit of priority based on Korean Patent Application No. 10-2019-0035031, filed on March 27, 2019, and all of the contents disclosed in the corresponding Korean patent application are incorporated herein by reference.

[0002] Technical Field This application relates to a resin composition, a method for manufacturing the same, and uses thereof.

Background Art

[0003] Secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, or lithium secondary batteries.

[0004] When a battery is applied to a medium- to large-sized device such as an automobile or a power storage device, a battery module in which a number of secondary batteries are electrically connected to each other to increase the capacity and output, or a battery pack in which a plurality of such battery modules are connected may be used.

[0005] The applicant of this application proposed a method for implementing the above-described battery module and battery pack using a thermally conductive adhesive material in Patent Document 1.

[0006] In the formation of a battery module using an adhesive material, it is necessary to appropriately ensure thixotropy. Thixotropy is a property in which the viscosity changes due to shear stress, and such a property is required during the manufacture of a battery module.

[0007] However, depending on the resin composition, it is difficult to ensure the above-described thixotropy. In particular, when a high content of filler is applied to ensure functions such as thermal conductivity, it is more difficult to ensure the above-described properties.

Prior Art Documents

Patent Documents

[0008] (Patent Document 0001) Korean Patent Publication No. 2016-0105354

Summary of the Invention

Problems to be Solved by the Invention

[0009] One object of the present application is to provide a resin composition excellent in one or more properties selected from thermal conductivity, adhesiveness, insulation, tensile properties, hardness, and flame retardancy, and having excellent thixotropy, a method for producing the same, and uses thereof.

Means for Solving the Problems

[0010] Among the physical properties mentioned in this specification, when the measurement temperature and / or pressure affect the physical property value, unless otherwise specified, the relevant physical property means the physical property measured at normal temperature and / or normal pressure.

[0011] In the present application, the term "normal temperature" is the natural temperature without heating or cooling, and for example, it can mean any one temperature within the range of about 10°C to 30°C, a temperature of about 25°C or 23°C. Also, unless otherwise specified, the temperature unit in this specification is °C.

[0012] In the present application, the term "normal pressure" is the pressure when not particularly reduced or increased, and it may be about 1 atmosphere like normal atmospheric pressure.

[0013] The present application relates to a resin composition.

[0014] In one example, the resin composition may be a curable resin composition. The resin composition may be an active energy ray curable type, moisture curable type, heat curable type, or normal temperature curable type, etc., and appropriately, it is a normal temperature curable type.

[0015] In one example, the resin composition may be an adhesive composition. The term "adhesive composition" can mean a composition designed to exhibit adhesiveness at a certain level or higher before or after curing. In one example, the resin composition that is an adhesive composition may exhibit an adhesive force of about 1,000 gf / 10 mm or less, about 950 gf / 10 mm or less, about 900 gf / 10 mm or less, about 850 gf / 10 mm or less, about 800 gf / 10 mm or less, about 750 gf / 10 mm or less, about 700 gf / 10 mm or less, about 650 gf / 10 mm or less, or about 600 gf / 10 mm or less before or after curing. In other examples, the adhesive force may be about 50 gf / 10 mm or more, about 70 gf / 10 mm or more, about 80 gf / 10 mm or more, or about 90 gf / 10 mm or more. The adhesive force may be the adhesive force to aluminum or the adhesive force to a polyester film.

[0016] The resin composition may be a one-component resin composition or a two-component resin composition. The term "one-component resin composition" means a resin composition formed so that it can be cured by itself without being mixed with other components, and the "two-component resin composition" means a resin composition formed so that it can be cured when mixed with other components. Usually, the two-component resin composition is stored with the curable resin and the curing agent separated, and for curing, the curable resin and the curing agent must come into contact. In this specification, the term "main agent composition" means a composition containing the curable resin among the two-component resin compositions, and the "curing agent composition" can mean a composition containing the curing agent among the two-component resin compositions.

[0017] In one example, the resin composition may be a resin composition used for the manufacture of a battery module or a battery pack. As exemplified below, the resin composition is injected into the interior of a battery module case among the specific disclosure contents of this application and can be used to fix battery cells in the battery module by contacting one or more battery cells present in the battery module.

[0018] The resin composition can contain a curable resin and / or a curing agent for the resin. In one example, the resin composition may be a main agent composition containing a curing agent among two-component resin compositions, or a curing agent composition containing a curing agent. In some cases, the resin composition is a composition in a state where the main agent composition and the curing agent composition are mixed, and can contain the curable resin and the curing agent simultaneously. At this time, the two components may be in a state of reacting with each other or in a state before reaction.

[0019] The resin may be a polyol compound. As the polyol compound, an ester polyol compound can be used in one example. The ester polyol is advantageous for enabling the resin composition to exhibit desired physical properties before or after curing.

[0020] The ester polyol may be an amorphous or polyol with sufficiently low crystallinity. As used herein, the term "amorphous" can mean a case where a crystallization temperature (Tc) and a melting temperature (Tm) are not observed in a predetermined DSC (Differential Scanning Calorimetry) analysis. The DSC analysis can be performed in the range of -80°C to 60°C at a heating or cooling rate of 10°C / min. For example, the DSC analysis can be performed in a manner of heating the temperature from 25°C to 60°C at the above rate and then cooling to -80°C and further heating to 60°C. Such DSC analysis follows a known method as long as it is performed within the above temperature range and heating / cooling rate.

[0021] The above-mentioned "low crystallinity of the polyol" means a case where the melting point (Tm) confirmed by the DSC analysis is 15°C or lower. In other examples, the melting point means a case where it is less than about 15°C, about 10°C or lower, 5°C or lower, 0°C or lower, -5°C or lower, -10°C or lower, or about -20°C or lower. The melting point may be, for example, about -80°C or higher, -75°C or higher, or about -70°C or higher. Applying a polyol compound with the above characteristics can more effectively ensure target physical properties such as thixotropy.

[0022] In one example, as the polyol compound as described above, a carboxylic acid polyol compound or a caprolactone polyol compound can be used.

[0023] The carboxylic acid polyol compound means a compound formed by reacting a component containing a carboxylic acid and a polyol (e.g., diol or triol, etc.), and the caprolactone polyol compound can mean a polyol formed by reacting a component containing caprolactone and a polyol (e.g., diol or triol, etc.). At this time, the carboxylic acid may be a dicarboxylic acid.

[0024] In one example, the polyol compound may be a polyol compound represented by the following Chemical Formula 1 or 2.

[0025]

Chemical Formula

[0026]

Chemical Formula

[0027] In Chemical Formulas 1 and 2, X is a unit derived from a carboxylic acid, and Y is a unit derived from a polyol. The unit derived from a polyol may be, for example, a triol unit or a diol unit. Also, n and m may be any numbers. For example, n is a number in the range of 2 to 10, m is a number in the range of 1 to 10, and R1 and R2 are each independently an alkylene having 2 to 14 carbon atoms.

[0028] As described above, the term "unit derived from carboxylic acid" may mean the portion of the carboxylic acid compound excluding the carboxyl group. Similarly, the term "unit derived from polyol" can mean the portion of the polyol compound structure excluding the hydroxy group. That is, when the hydroxy group of the polyol reacts with the carboxyl group of the carboxylic acid, an ester bond is formed while a water (H2O) molecule is eliminated by a condensation reaction. Thus, when a carboxylic acid forms an ester bond by a condensation reaction, the unit derived from the carboxylic acid can mean the portion of the carboxylic acid structure that does not participate in the condensation reaction. Also, the unit derived from the polyol can mean the portion of the polyol structure that does not participate in the condensation reaction.

[0029] Y in Chemical Formula 2 also represents the portion of the polyol after forming an ester bond with caprolactone and excluding that ester bond. That is, in Chemical Formula 2, for the unit derived from the polyol, Y, when the polyol and caprolactone form an ester bond, it can mean the portion of the polyol structure that does not participate in the ester bond. The ester bonds are shown in Chemical Formulas 1 and 2, respectively.

[0030] In the above chemical formula, when the unit derived from the polyol of Y is a unit derived from a polyol containing 3 or more hydroxy groups such as a triol unit, a branched structure can be embodied in the Y portion in the chemical formula structure.

[0031] In Chemical Formula 1, the type of the unit derived from the carboxylic acid of X is not particularly limited, but for ensuring the desired physical properties, it may be a unit derived from one or more compounds selected from the group consisting of a fatty acid compound, an aromatic compound having 2 or more carboxyl groups, an alicyclic compound having 2 or more carboxyl groups, and an aliphatic compound having 2 or more carboxyl groups.

[0032] The aromatic compound having 2 or more carboxyl groups may, in one example, be phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, or tetrachlorophthalic acid.

[0033] The alicyclic compound having two or more carboxyl groups is, as one example, may be tetrahydrophthalic acid, hexahydrophthalic acid, or tetrachlorophthalic acid.

[0034] The aliphatic compound having two or more carboxyl groups is, as one example, may be oxalic acid, adipic acid, azelaic acid, sebacic acid, succinic acid, malic acid, glutaric acid, malonic acid, pimelic acid, suberic acid, 2,2-dimethylsuccinic acid, 3,3-dimethylglutaric acid, 2,2-dimethylglutaric acid, maleic acid, fumaric acid, or itaconic acid.

[0035] From the aspect of ensuring an appropriate glass transition temperature within the range described above, units derived from aliphatic carboxylic acids can be applied.

[0036] In Chemical Formulas 1 and 2, the type of the unit derived from the polyol of Y is not particularly limited, but in order to ensure the desired physical properties, it may be derived from one or more compounds selected from the group consisting of an alicyclic compound having two or more hydroxy groups and an aliphatic compound having two or more hydroxy groups.

[0037] The alicyclic compound having two or more hydroxy groups is, as one example, may be 1,3-cyclohexanedimethanol or 1,4-cyclohexanedimethanol.

[0038] The aliphatic compound having two or more hydroxy groups is, as one example, may be ethylene glycol, propylene glycol, 1,2-butylene glycol, 2,3-butylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, 1,2-ethylhexyl diol, 1,5-pentanediol, 1,9-nonanediol, 1,10-decanediol, glycerin, or trimethylolpropane.

[0039] In Chemical Formula 1, n is an arbitrary number, and its range can be selected in consideration of the physical properties intended for the resin layer that is the resin composition or its cured product. For example, n may be about 2 to 10 or 2 to 5.

[0040] In Chemical Formula 2, m is an arbitrary number, and its range can be selected in consideration of the physical properties intended for the resin layer that is the resin composition or its cured product. For example, m may be about 1 to 10 or 1 to 5.

[0041] In Chemical Formulas 1 and 2, as n and m increase, the polyol compound becomes longer-chained, and such long chains increase the probability that the polyol compound can exhibit crystallinity. Therefore, in order to ensure the above-described non-crystalline or sufficiently low crystallinity, it is advantageous that n and m be determined within the above-described ranges.

[0042] In Chemical Formula 2, R1 and R2 are each independently an alkylene within the range of 2 to 14 carbon atoms. The number of carbon atoms can be selected in consideration of the physical properties intended for the resin layer that is the resin composition or its cured product.

[0043] The molecular weight of the polyol can be adjusted in consideration of the durability or adhesiveness described below, etc., and for example, it may be within the range of about 300 to 2,000. Unless otherwise specified, the term "molecular weight" in this specification may be the weight average molecular weight (Mw) measured using GPC (Gel Permeation Chromatograph). When outside the above range, problems related to poor reliability of the resin layer after curing or volatile components may occur.

[0044] When the curable resin is a polyol compound, an isocyanate compound can be applied as the curing agent. As the isocyanate compound, a non-aromatic or aromatic isocyanate compound can be used, but using a non-aromatic polyisocyanate is effective when considering the reaction rate, glass transition temperature, processability, etc., but is not limited thereto.

[0045] Examples of the non-aromatic isocyanate compound include aliphatic polyisocyanates such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, norbornane diisocyanate methyl, ethylene diisocyanate, propylene diisocyanate or tetramethylene diisocyanate; alicyclic polyisocyanates such as trans-cyclohexane-1,4-diisocyanate, isophorone diisocyanate, bis(isocyanatomethyl)cyclohexane diisocyanate or dicyclohexylmethane diisocyanate; or carbodiimide-modified polyisocyanates or isocyanurate-modified polyisocyanates of any one of the above; etc. can be used. Further, a mixture of two or more of the listed compounds can be used.

[0046] When the polyol compound and the isocyanate compound are simultaneously contained in the resin composition, the ratio is not particularly limited. That is, usually, since the hydroxy group of the polyol compound and the isocyanate group of the curing agent react in a 1:1 ratio to cause curing, an appropriate ratio can be selected in consideration of this.

[0047] The resin composition contains particles together with the curable resin and / or the curing agent. The particles may be non-ceramic particles or organic particles.

[0048] The particles can have a predetermined hardness. Particles having a controlled hardness can impart the desired thixotropy to the resin composition. Without being limited by theory, it is expected that the particles form a powder by contact with other components or contact between the particles during the production process of the resin composition described below, and the desired thixotropy is ensured by such a powder.

[0049] In one example, after milling with zirconium beads having a particle size of 1 mm for 20 hours, the change rate of the D50 particle size of the particles may be in the range of -95% to -80%. In the above, the change rate of the D50 particle size is a value calculated by 100×(D50a - D50i) / D50i, where D50i is the D50 particle size before the milling and D50a is the D50 particle size after the milling. That is, the particles can have a hardness that results in a D50 particle size change rate within the above range during milling with the zirconium beads. In other examples, the change rate of the D50 particle size may be -94% or more, -93% or more, -92% or more, -91% or more, or -90% or more, or -81% or less, -82% or less, -83% or less, -84% or less, -85% or less, -86% or less, -87% or less, or -88% or less.

[0050] In one example, after milling with zirconium beads having a particle size of 1 mm for 20 hours, the change rate of the D10 particle size of the particles may be in the range of -85% to -70%. In the above, the change rate of the D10 particle size is a value calculated by 100×(D10a - D10i) / D10i, where D10i is the D10 particle size before the milling and D10a is the D10 particle size after the milling. That is, the particles can have a hardness that results in a D10 particle size change rate within the above range during milling with the zirconium beads. In other examples, the change rate of the D10 particle size may be -84% or more, -83% or more, -82% or more, -81% or more, or -80% or more, or -71% or less, -72% or less, -73% or less, -74% or less, -75% or less, -76% or less, -77% or less, or -78% or less.

[0051] In one example, after milling with zirconium beads having a particle size of 1 mm for 20 hours, the change rate of the D90 particle size may be in the range of -95% to -80%. In the above, when the change rate of the D90 particle size is calculated with the D90 particle size before milling as D90i and the D90 particle size after milling as D90a, it is a value calculated by 100×(D90a - D90i) / D90i. That is, the particles can have a hardness that results in a D90 particle size change rate within the above range during milling with the zirconium beads. In other examples, the change rate of the D90 particle size may be -94% or more, -93% or more, or -92% or more, or -81% or less, -82% or less, -83% or less, -84% or less, -85% or less, -86% or less, -87% or less, -88% or less, -89% or less, -90% or less, or -91% or less.

[0052] The D10, D50, and D90 particle sizes mentioned above are the particle diameters at 10%, 50%, and 90% volume-based cumulative in the volume-based cumulative curve of the particle size distribution, and the method for obtaining such particle sizes is known. For example, the particle size distribution of particles is determined on a volume basis, and the particle diameters at the points where the cumulative values are 10%, 50%, and 90% respectively on the cumulative curve with the total volume set to 100% are defined as the D10, D50, and D90 particle sizes. The method for obtaining such particle sizes is known, and for example, the particle size can be obtained by laser diffraction or the like.

[0053] In one example, the D50 particle size of the particles may be in the range of 1 to 10 μm. In other examples, the D50 particle size may be about 1.2 μm or more, 1.4 μm or more, 1.6 μm or more, 1.8 μm or more, 2 μm or more, or 2.2 μm or more, or 9.5 μm or less, 9 μm or less, 8.5 μm or less, 8 μm or less, 7.5 μm or less, 7 μm or less, 6.5 μm or less, 6 μm or less, 5.5 μm or less, 5 μm or less, 4.5 μm or less, 4 μm or less, 3.5 μm or less, 3 μm or less, or 2.5 μm or less.

[0054] The ratio (D90 / D50) of the D50 particle size (D50) to the D90 particle size (D90) of the particles may be in the range of 1.5 to 5. In other examples, the ratio (D90 / D50) may be about 2 or more, or 2.5 or more, or may be about 4.5 or less, 4 or less, 3.5 or less, or 3 or less.

[0055] The ratio (D50 / D10) of the D50 particle size (D50) to the D10 particle size (D10) of the particles may be in the range of 3.5 to 6. In other examples, the ratio (D50 / D10) may be about 4 or more, or may be about 5.5 or less, 5 or less, 4.5 or less, or 4 or less.

[0056] Particles having the above hardness characteristics and particle size distribution characteristics, etc., can impart appropriate thixotropy to the resin composition.

[0057] For the particles, as long as they have the above-mentioned hardness characteristics and, if necessary, the particle size distribution mentioned above, various types can be applied without special restrictions, and their forms are also not particularly restricted. Examples of applicable particles can include known clay particles, silica particles, CaCO3 particles, Al(OH)3 particles, and / or ZnO particles, etc. Substantially, there are no major restrictions on the types applicable to the particles. For example, as long as the particles have a lower hardness than the heat-conductive particles to be applied, all can be applied.

[0058] In one example, the particles may be flame retardant particles. The applicant has confirmed that various types of particles known as particulate flame retardants can effectively satisfy the hardness characteristics and particle size distribution. Applying such flame retardant particles can also exert the effect of imparting flame retardancy to the resin composition or resin layer while ensuring thixotropy.

[0059] As the flame retardant particles, known flame retardant particles can be used without special restrictions. For example, among the components known as phosphorus-based particulate flame retardants, those that satisfy the hardness and / or particle size characteristics can be applied.

[0060] The ratio of the particles can be selected in consideration of the desired thixotropy or the like and is not particularly limited. In one example, the particles can be included in the resin composition at a ratio of about 5 to 30 parts by weight based on 100 parts by weight of the curable resin or curing agent. In other examples, the particles can be included in an amount of about 10 parts by weight or more, or about 13 parts by weight or more, or can be included in an amount of about 25 parts by weight or less, or about 20 parts by weight or less.

[0061] As long as the resin composition basically contains the components described above, it can also contain various other components.

[0062] For example, the resin composition can further contain a filler component known as a so-called thermal conductivity filler. The term "thermal conductivity filler" can mean a filler known to have a thermal conductivity of about 1 W / mK or more, 5 W / mK or more, 10 W / mK or more, or about 15 W / mK or more. The thermal conductivity of the thermal conductivity filler may be about 400 W / mK or less, 350 W / mK or less, or about 300 W / mK or less. The type of the thermal conductivity filler is not particularly limited, but when considering insulation properties and the like together, an inorganic filler, for example, a ceramic filler can be applied. For example, ceramic particles such as alumina, AlN (aluminum nitride), BN (boron nitride), silicon nitride, SiC, or BeO can be used. In addition to the above, various types of fillers can be used. For example, in order to ensure the insulation properties of the resin layer obtained by curing the resin composition, the use of a carbon filler such as graphite can be considered. Or, for example, fillers such as fumed silica, clay, or calcium carbonate can be used.

[0063] The filler can be included in a very high content in the resin composition. For example, the filler can be used in a proportion of about 50 parts by weight or more, about 100 parts by weight or more, about 150 parts by weight or more, about 200 parts by weight or more, about 250 parts by weight or more, about 300 parts by weight or more, about 350 parts by weight or more, about 400 parts by weight or more, about 450 parts by weight or more, about 500 parts by weight or more, about 550 parts by weight or more, about 600 parts by weight or more, about 650 parts by weight or more, about 700 parts by weight or more, about 750 parts by weight or more, about 800 parts by weight or more, 820 parts by weight or more, or about 840 parts by weight or more with respect to 100 parts by weight of the curable resin and / or the curing agent. The filler may be used in an amount of about 2,000 parts by weight or less, 1,800 parts by weight or less, or about 1,600 parts by weight or less with respect to 100 parts by weight of the curable resin and / or the curing agent.

[0064] In order to effectively maintain viscosity characteristics and the like even by applying an excessive amount of the filler and to more effectively use the target thermal conductivity, insulation, etc., at least three kinds of fillers having different average particle sizes from each other can be applied as the filler.

[0065] For example, the thermally conductive filler can at least include a first inorganic filler having an average particle size in the range of about 1 μm to about 3 μm, a second inorganic filler having an average particle size in the range of about 15 μm to about 25 μm, and a third inorganic filler having an average particle size in the range of about 35 μm to about 200 μm. The average particle size of the filler means the D50 particle size among the above-mentioned particle sizes. In such a case, when the total weight of the filler is 100 parts by weight, the first inorganic filler is included in an amount of about 15 to about 35 parts by weight or about 20 to about 30 parts by weight, the second inorganic filler is included in an amount of about 25 to about 45 parts by weight or about 30 to about 40 parts by weight, and the third inorganic filler can be included in an amount of about 30 to about 50 parts by weight or about 35 to about 45 parts by weight.

[0066] By applying the three kinds of fillers having the above-mentioned particle sizes in the above-mentioned ratio, it is possible to provide a resin composition that exhibits an appropriate viscosity and ensures handleability even when filled with a high content of the filler.

[0067] The form of the inorganic filler is not particularly limited and can be selected in consideration of the viscosity and thixotropy of the resin composition, the possibility of sedimentation in the resin composition, thermal conductivity, insulation, filling effect, dispersibility, etc. For example, considering the amount to be filled, it is advantageous to use spherical inorganic fillers. However, non-spherical inorganic fillers, such as those in the form of needles or plates, etc., can also be used in consideration of network formation, conductivity, thixotropy, etc.

[0068] In this application, the term "spherical particles" means particles with a sphericity of about 0.95 or more, and "non-spherical particles" means particles with a sphericity of less than 0.95. The sphericity can be confirmed through particle shape analysis of the particles.

[0069] In one example, considering the filling effect described above, all spherical fillers, that is, fillers with a sphericity of 0.95 or more, can be used as the first to third inorganic fillers. In another example, at least one of the first to third inorganic fillers may be a non-spherical filler with a sphericity of less than 0.95.

[0070] The resin composition can contain other known additives in addition to the above components. Examples of such additives can include, but are not limited to, the catalyst, viscosity modifier, diluent, dispersant, surface treatment agent, or coupling agent, etc.

[0071] As the catalyst, for example, a tin catalyst such as dibutyltin dilaurate (DBTDL) can be used. The catalyst can be contained in an amount of 0.1 to 0.5 parts by weight based on 100 parts by weight of the curable resin or curing agent contained in the resin composition. In one example, the catalyst can be contained in an amount of about 0.1 part by weight or more, 0.15 part by weight or more, or about 0.2 part by weight or more, or about 0.5 part by weight or less, 0.45 part by weight or less, 0.4 part by weight or less, 0.35 part by weight or less, or about 0.3 part by weight or less based on 100 parts by weight of the curable resin or curing agent.

[0072] The dispersant is not particularly limited, and compound form, nonionic, anionic or cationic dispersants can be used, and fluorine-based, ester-based, cationic, anionic, nonionic, amphoteric surfactants, etc. can also be used. As an example, a cationic dispersant having a phosphate group or a phosphite group can be used as the dispersant. The dispersant can be used in an amount of 0.01 to 0.5 parts by weight based on 100 parts by weight of the curable resin and / or the curing agent.

[0073] As the flame retardant, a phosphorus-based flame retardant can be applied, and a flame retardant that is liquid at room temperature, a solid-phase flame retardant, or a semi-solid-phase flame retardant can be used. The liquid phosphorus-based flame retardant is a flame retardant that is liquid at room temperature, and may have a melting point lower than room temperature, for example, lower than about 30 °C, lower than 25 °C, lower than 20 °C, lower than 15 °C, lower than 10 °C. As an example of the liquid phosphorus-based flame retardant, a phosphate-based flame retardant such as resorcinol bis(diphenyl phosphate) can be used. The liquid phosphorus-based flame retardant can contain about 5 to 25 parts by weight based on 100 parts by weight of the total resin content.

[0074] The diluent or dispersant is usually used to lower the viscosity of the resin composition, and various types known in the industry can be used without limitation as long as they can exhibit the above-mentioned effects.

[0075] The surface treatment agent is for surface treatment of the filler, and various types known in the industry can be used without limitation as long as they can exhibit the above-mentioned effects.

[0076] In the case of the coupling agent, for example, it can be used to improve the dispersibility of a heat-conductive filler such as alumina, and various types known in the industry can be used without limitation as long as they can exhibit the above-mentioned effects.

[0077] As described above, the resin composition can exhibit excellent thixotropy. In one example, the resin composition can exhibit a thixotropic index greater than about 1. In other examples, the thixotropic index can be about 1.2 or greater, about 1.4 or greater, about 1.6 or greater, or about 1.8 or greater, or can be about 10 or less, about 9 or less, about 8 or less, about 7 or less, about 6 or less, about 5 or less, about 3.5 or less, or about 3.2 or less. As described above, the thixotropic index is the ratio of the viscosity (V 0.1 ) at a shear rate of 0.1 / s to the viscosity (V 1.0 ) at a shear rate of 1.0 / s (V 0.1 / V 1.0 ), measured using a rheometer (ARES).

[0078] When the thixotropic index value of the resin composition satisfies the above range, filling and injection in the injection equipment are facilitated and appropriate processability can be ensured.

[0079] The present application also relates to a method for manufacturing the resin composition.

[0080] The resin composition can be basically produced by mixing the above-described curable resin or a curing agent for the resin with the particles having the above-described characteristics.

[0081] In such a mixing process, a predetermined powder is formed by contact between the particles, and the desired thixotropy can be ensured by such a powder.

[0082] The applicant of the present application has confirmed that the desired thixotropy can be more effectively ensured by controlling the mixing method of the particles. For example, when the resin composition contains the above-described thermal conductive filler, and various types of fillers having different average particle diameters are applied as the filler, the particles are effective in achieving the desired thixotropy when mixed with the filler having the smallest average particle diameter.

[0083] Therefore, the manufacturing method can include a curing agent for the curable resin or the resin; a first step of forming a mixture of the particles and the thermally conductive filler; and a second step of mixing the mixture of the first step with a thermally conductive filler having an average particle size larger than that of the thermally conductive filler of the first step. In the first step, the thermally conductive filler to be mixed may be the first thermally conductive filler among the first to third thermally conductive fillers described above, and in the second step, it may be the second and / or third thermally conductive filler.

[0084] In such a manufacturing method, when other components except the curable resin or curing agent, filler, and particles are applied, there are no special restrictions on the charging order. For example, when a catalyst, a dispersant, and / or a liquid flame retardant among the above-mentioned components are applied, a step of mixing the curable resin and the catalyst, and then mixing the dispersant and the liquid flame retardant, and then mixing the filler and the particles can be performed.

[0085] That is, when the above-mentioned order is observed during the mixing of the particles and the thermally conductive filler described above, other components can be mixed in an appropriate order according to the purpose, and the form of mixing may also be to mix all the amounts at once or to divide and mix appropriately.

[0086] The present application also relates to a resin layer including the resin composition described above. Such a resin layer may be a resin layer formed by curing the resin composition. That is, when the resin composition is of the one-component type, the resin composition can cure itself to form the resin layer, and when it is of the two-component type, it may be cured after the main agent and the curing agent composition are mixed to form the resin layer.

[0087] Such a resin layer is a thermally conductive resin layer, and the thermal conductivity may be about 2 W / mK or more, 2.5 W / mK or more, 3 W / mK or more, 3.5 W / mK or more, or about 4 W / mK or more. The thermal conductivity may be about 50 W / mK or less, 45 W / mK or less, 40 W / mK or less, 35 W / mK or less, 30 W / mK or less, 25 W / mK or less, 20 W / mK or less, 15 W / mK or less, 10 W / mK or less, 5 W / mK or less, 4.5 W / mK or less, or about 4.0 W / mK or less. The thermal conductivity of the resin layer is, for example, a numerical value measured according to the ASTM D5470 standard or the ISO 22007-2 standard. The thermal conductivity of the resin layer as described above can be ensured by appropriately adjusting the filler and its content ratio.

[0088] In another example, the resin layer can have a predetermined adhesive force (S1) before or after curing. Specifically, a resin layer formed by curing a two-component resin composition can have an adhesive force of about 150 gf / 10 mm or more, 200 gf / 10 mm or more, 250 gf / 10 mm or more, 300 gf / 10 mm or more, 350 gf / 10 mm or more, or about 400 gf / 10 mm or more. When the adhesive force satisfies the above range, appropriate impact resistance and vibration resistance can be ensured. The upper limit of the adhesive force of the resin layer is not particularly limited and may be, for example, about 1,000 gf / 10 mm or less, 900 gf / 10 mm or less, 800 gf / 10 mm or less, 700 gf / 10 mm or less, 600 gf / 10 mm or less, or about 500 gf / 10 mm or less. If the adhesive force is excessively high, there is a risk that the cured two-component resin composition and the attached pouch portion will break. Specifically, when an impact occurs during the running of an automobile such that the form of the battery module is deformed due to an accident, if the battery cells are excessively strongly attached through the cured resin layer, the pouch may break and dangerous substances inside the battery may be exposed or may explode. The adhesive force can be measured with respect to an aluminum pouch. For example, an aluminum pouch used in the production of battery cells is cut at a width of about 10 mm, a two-component resin composition is loaded onto a glass plate, and the cut aluminum pouch is loaded thereon such that the PET (poly(ethylene terephthalate)) surface of the pouch contacts the two-component resin composition. Then, the two-component resin composition is cured for 24 hours under conditions of 25 °C and 50% RH, and the adhesive force can be measured while peeling the aluminum pouch with a tensile tester (Texture analyzer) at a peeling angle of 180° and a peeling speed of 300 mm / min.

[0089] In another example, the adhesive strength after curing of the two-component resin composition can be maintained at a considerable level even under high temperature / high humidity, as described in the following examples. Specifically, in this application, after conducting an accelerated test of high temperature / high humidity under predetermined conditions on the adhesive strength (S1) after curing measured at room temperature, the percentage ratio [(S2 / S1) x 100] of the adhesive strength (S2) measured by the same method may be 70% or more, or 80% or more. In one example, the high temperature / high humidity accelerated test can be measured after storing the same specimen as the specimen used to measure the room temperature adhesive strength under temperature conditions of 40 to 100 °C and humidity conditions of 75% RH or more for 10 days. When the adhesive strength and the relationship are satisfied, excellent adhesive durability can be maintained even when the usage environment of the battery module changes.

[0090] In another example, the two-component resin composition can have excellent heat resistance after curing. In this regard, when performing thermogravimetric analysis (TGA) on the cured product of only the resin component without containing a filler for the two-component resin composition of this application, the temperature of 5% weight loss may be 120 °C or more. Also, when performing thermogravimetric analysis (TGA) on the cured product of the two-component resin composition in a state containing a filler for the two-component resin composition of this application, the remaining amount at 800 °C may be 70% by weight or more. In other examples, the remaining amount at 800 °C may be about 75% by weight or more, about 80% by weight or more, about 85% by weight or more, or about 90% by weight or more. In other examples, the remaining amount at 800 °C may be about 99% by weight or less. At this time, the thermogravimetric analysis (TGA) can be measured in a nitrogen (N2) atmosphere at 60 cm 3 / min at a heating rate of 20 °C / min in the range of 25 to 800 °C. The heat resistance characteristics related to the thermogravimetric analysis (TGA) can be ensured by adjusting the types and contents of the resin and / or filler.

[0091] In one example, the two-component resin composition can have excellent electrical insulation properties after curing. When the resin layer exhibits a predetermined electrical insulation property in the structure of the battery module described below, the performance of the battery module can be maintained and stability can be ensured. For example, the cured product of the two-component resin composition may have a dielectric breakdown voltage of about 10 kV / mm or more, 15 kV / mm or more, or 20 kV / mm or more as measured in accordance with ASTM D149. The higher the value of the dielectric breakdown voltage, the better the insulation property of the resin layer, and although it is not particularly limited, considering the composition of the resin layer, etc., it may be about 50 kV / mm or less, 45 kV / mm or less, 40 kV / mm or less, 35 kV / mm or less, or about 30 kV / mm or less. The dielectric breakdown voltage within the above range can be ensured, for example, by adjusting the content of the filler and resin component described above.

[0092] Further, the present application relates to a battery module. The module includes a module case and battery cells. The battery cells may be housed within the module case. One or more battery cells can be present within the module case, and a plurality of battery cells may be housed within the module case. The number of battery cells housed within the module case is adjusted according to the application, etc., and is not particularly limited. The battery cells housed within the module case may be electrically connected to each other.

[0093] The module case can include at least a side wall and a lower plate that form an internal space in which the battery cells can be housed. Further, the module case can further include an upper plate that seals the internal space. The side wall, the lower plate, and the upper plate may be integrally formed with each other, or the separated side wall, lower plate, and / or upper plate may be assembled to form the module case. The form and size of such a module case are not particularly limited and can be appropriately selected according to the application and the form and number of the battery cells housed within the internal space.

[0094] As described above, the terms "upper plate" and "lower plate" are relative terms used to distinguish between at least two plates that make up the module case. That is, it does not necessarily mean that the upper plate must be on top and the lower plate must be at the bottom in the actual usage state.

[0095] FIG. 1 is a diagram showing an exemplary module case 10, which is an example of a box-shaped module case 10 including one lower plate 10a and four side walls 10b. The module case 10 can further include an upper plate 10c that seals the internal space.

[0096] FIG. 2 is a schematic view of the module case 10 of FIG. 1 in which the battery cells 20 are housed, as observed from above.

[0097] Holes may be formed in the lower plate, side walls, and / or upper plate of the module case. The holes may be injection holes used for injecting the forming material of the resin layer, that is, a two-component resin composition, when forming the resin layer by an injection process. The shape, number, and position of the holes can be adjusted in consideration of the injection efficiency of the forming material of the resin layer. In one example, the holes may be formed at least in the lower plate and / or the upper plate.

[0098] In one example, the holes may be formed at about 1 / 4 to 3 / 4 or about 3 / 8 to 7 / 8 or substantially in the middle of the entire length of the side wall, lower plate, or upper plate. By injecting the two-component resin composition through the injection holes formed at this position, the resin layer can be injected so as to have a wide contact area. The 1 / 4, 3 / 4, 3 / 8, or 7 / 8 position is, for example, the ratio of the distance A reaching the formation position of the hole to the total length L measured with respect to any one end face E, such as the lower plate, as shown in FIG. 3. Also, the end E at which the length L and the distance A are formed may be any end E as long as the length L and the distance A are measured from the same end E. In FIG. 3, the injection hole 50a is located substantially in the middle of the lower plate 10a.

[0099] The size and shape of the injection holes are not particularly limited and can be adjusted in consideration of the injection efficiency of the resin layer material described later. For example, the holes may be circular, elliptical, polygonal such as triangular or quadrilateral, or amorphous. The number of injection holes and the intervals between them are also not particularly limited, and can be adjusted so that the resin layer has a wide contact area with the lower plate or the like as described above.

[0100] Observation holes (e.g., 50b in FIG. 3) may be formed at the ends of the upper plate and lower plate where the injection holes are formed. Such observation holes may be formed, for example, to observe whether the injected material is well injected up to the ends of the side walls, lower plate, or upper plate when injecting the resin layer material through the injection holes. The position, form, size, and number of the observation holes are not particularly limited as long as they are formed so that it is possible to confirm whether the injected material is properly injected.

[0101] The module case may be a heat-conductive case. The term "heat-conductive case" means a case in which the thermal conductivity of the entire case is 10 W / mK or more, or a case including at least a part having the above thermal conductivity. For example, at least one of the side walls, lower plate, and upper plate described above can have the above thermal conductivity. In another example, at least one of the side walls, lower plate, and upper plate can include a part having the above thermal conductivity. For example, the battery module of the present application can include a first filler-containing cured resin layer in contact with the upper plate and the battery cell and a second filler-containing cured resin layer in contact with the lower plate and the battery cell. However, at least the second filler-containing cured resin layer may be a heat-conductive resin layer, whereby at least the lower plate can have thermal conductivity or include a heat-conductive part.

[0102] The thermal conductivity of the upper plate, lower plate, side wall or thermally conductive part that is thermally conductive as described above may, in other examples, be about 20 W / mK or more, 30 W / mK or more, 40 W / mK or more, 50 W / mK or more, 60 W / mK or more, 70 W / mK or more, 80 W / mK or more, 90 W / mK or more, 100 W / mK or more, 110 W / mK or more, 120 W / mK or more, 130 W / mK or more, 140 W / mK or more, 150 W / mK or more, 160 W / mK or more, 170 W / mK or more, 180 W / mK or more, 190 W / mK or more, or about 195 W / mK or more. Since the higher the numerical value of the thermal conductivity, the more advantageous it is in aspects such as the heat dissipation characteristics of the module, the upper limit is not particularly limited. In one example, the thermal conductivity may be about 1,000 W / mK or less, 900 W / mK or less, 800 W / mK or less, 700 W / mK or less, 600 W / mK or less, 500 W / mK or less, 400 W / mK or less, 300 W / mK or 250 W / mK or less, but it is not limited thereto. The type of material showing the thermal conductivity as described above is not particularly limited, and examples include metal materials such as aluminum, gold, silver, tungsten, copper, nickel or platinum. The module case may be entirely made of the thermally conductive material as described above, or at least a part of the part may be made of the thermally conductive material. Thereby, the module case can have the thermal conductivity within the mentioned range or include at least one part having the mentioned thermal conductivity.

[0103] The part having the thermal conductivity within the above range in the module case may be a part in contact with the resin layer and / or the insulating layer. Also, the part having the thermal conductivity may be a part in contact with a cooling medium such as cooling water. When having such a structure, the heat generated from the battery cell can be effectively released to the outside.

[0104] In the present application, the term "battery cell" means a single secondary battery configured to include an electrode assembly and an exterior material.

[0105] The type of battery cells housed in the battery module case is not particularly limited, and all known various battery cells can be applied. As an example, the battery cell may be a pouch type.

[0106] The battery module of the present application can further include a resin layer. Specifically, the battery module of the present application can include a cured resin layer obtained by curing a filler-containing composition. The cured resin layer can be formed from the two-component resin composition described above.

[0107] The battery module can include, as the resin layer, a first cured resin layer in contact with the upper plate and the battery cells, and a second cured resin layer in contact with the lower plate and the battery cells. One or more of the first and second cured resin layers can include a cured product of the two-component resin composition described above, thereby having the predetermined adhesive strength, cold resistance, heat resistance, and insulation properties described above.

[0108] In addition, the first and second cured resin layers may be heat-conductive resin layers. In such a case, the thermal conductivity of the heat-conductive resin layer may be about 1.5 W / mK or more, about 2 W / mK or more, 2.5 W / mK or more, 3 W / mK or more, 3.5 W / mK or more, or about 4 W / mK or more. The thermal conductivity may be about 50 W / mK or less, 45 W / mK or less, 40 W / mK or less, 35 W / mK or less, 30 W / mK or less, 25 W / mK or less, 20 W / mK or less, 15 W / mK or less, 10 W / mK or less, 5 W / mK or less, 4.5 W / mK or less, or about 4.0 W / mK or less. As described above, when the resin layer is a heat-conductive resin layer, the lower plate, upper plate, and / or side wall to which the resin layer is attached may be a part having the above-described thermal conductivity of 10 W / mK or more. At this time, the part of the module case indicating the thermal conductivity may be a part in contact with a cooling medium, for example, cooling water. The thermal conductivity of the resin layer is, for example, a value measured according to ASTM D5470 standard or ISO 22007-2 standard. The thermal conductivity of the resin layer as described above can be ensured, for example, by appropriately adjusting the filler contained in the resin layer and its content ratio as described above.

[0109] Further, the resin layer may be a flame-retardant resin layer. In the present application, the term "flame-retardant resin layer" can mean a resin layer that exhibits a V-0 rating in the UL 94 V Test (Vertical Burning Test). Through this, stability against fires and other accidents that may occur from the battery module can be ensured.

[0110] At least one of the side wall, lower plate, and upper plate in contact with the resin layer in the battery module of the present application may be the above-described thermally conductive side wall, lower plate, or upper plate. On the other hand, in this specification, the term "contact" can mean, for example, whether the resin layer is in direct contact with the upper plate, lower plate, and / or side wall or battery cell, or whether there are other elements, such as an insulating layer, between them. Also, the resin layer in contact with the thermally conductive side wall, lower plate, or upper plate may be in thermal contact with the object. At this time, thermal contact means that the resin layer is in direct contact with the lower plate or the like, or there are other elements, such as an insulating layer described later, between the resin layer and the lower plate or the like, but the other elements do not impede the heat transfer from the battery cell to the resin layer and then from the resin layer to the lower plate or the like. "Not impeding heat transfer" as described above means that even when there are other elements (e.g., an insulating layer or a guide portion described later) between the resin layer and the lower plate or the like, the overall thermal conductivity of the other elements and the resin layer is about 1.5 W / mK or more, 2 W / mK or more, 2.5 W / mK or more, 3 W / mK or more, 3.5 W / mK or more, or about 4 W / mK or more, or the overall thermal conductivity of the resin layer and the lower plate or the like in contact with it is within the above range even when there are the other elements. The thermal conductivity of the thermal contact may be about 50 W / mK or less, 45 W / mK or less, 40 W / mK or less, 35 W / mK or less, 30 W / mK or less, 25 W / mK or less, 20 W / mK or less, 15 W / mK or less, 10 W / mK or less, 5 W / mK or less, 4.5 W / mK or less, or about 4.0 W / mK or less. Such thermal contact can be achieved by controlling the thermal conductivity and / or thickness of the other elements when the other elements are present.

[0111] The heat-conductive resin layer is in thermal contact with the lower plate or the like, and may also be in thermal contact with the battery cell. By adopting the above structure, when constructing a general battery module or a battery pack which is an assembly of such modules, various fastening parts and cooling equipment of modules required in the prior art can be significantly reduced, heat dissipation characteristics can be ensured, and a module in which more battery cells are accommodated per unit volume can be realized. Accordingly, in the present application, a smaller, lighter and higher-output battery module can be provided.

[0112] FIG. 4 is an exemplary cross-sectional view of the battery module. In FIG. 4, the module may be in a form including a case 10 including a side wall 10b and a lower plate 10a; a plurality of battery cells 20 housed inside the case; and a resin layer 30 in contact with all of the battery cells 20 and the case 10. Although FIG. 4 is a view of the resin layer 30 existing on the lower plate 10a side, the battery module of the present application may include a resin layer positioned in a form as shown in FIG. 4 also on the upper plate side.

[0113] The lower plate or the like in contact with the resin layer in the above structure may be a heat-conductive lower plate or the like as described above.

[0114] The contact area between the resin layer and the lower plate or the like may be about 70% or more, 75% or more, 80% or more, 85% or more, 90% or more, or about 95% or more with respect to the total area of the lower plate or the like. The upper limit of the contact area is not particularly limited, and may be, for example, 100% or less or about less than 100%.

[0115] When the upper plate or the lower plate is thermally conductive and the cured resin layer in contact therewith is also thermally conductive, the thermally conductive portion or the thermally conductive lower plate, etc. may be a portion in contact with a cooling medium such as cooling water. That is, as schematically shown in FIG. 4, heat H can be easily discharged to the lower plate or the like by the above-described structure, and by bringing such a lower plate or the like into contact with the cooling medium CW, heat can be easily released even in a simpler structure.

[0116] The resin layers may each have a thickness within a range of, for example, about 100 μm to 5 mm or within a range of about 200 μm to 5 mm. In the structure of the present application, the thickness of the resin layer can be set to an appropriate thickness in consideration of the target heat dissipation characteristics and durability. The thickness may be the thickness of the thinnest portion, the thickest portion, or the average thickness of the resin layer.

[0117] As shown in FIG. 4, on at least one surface inside the module case 10, for example, on the surface 10a in contact with the resin layer 30, there may be a guide portion 10d that can guide the battery cell 20 to be housed. At this time, the shape of the guide portion 10d is not particularly limited, and an appropriate shape can be adopted in consideration of the form of the battery cell to be applied. The guide portion 10d may be integrally formed with the lower plate or the like, or may be attached separately. The guide portion 10d can be formed using a thermally conductive material, for example, a metal material such as aluminum, gold, silver, tungsten, copper, nickel, or platinum, in consideration of the above-described thermal contact. Also, although not shown in the drawings, there may be an insulating paper or an adhesive layer between the battery cells 20 to be housed. The insulating paper described above can serve as a buffer during charging and discharging of the battery cell.

[0118] In one example, the battery module can further include an insulating layer between the module case and the battery cell or between the resin layer and the module case. FIG. 5 illustratively shows a case where an insulating layer 40 is formed between a guide portion 10d formed on the lower plate 10a of the case and the resin layer 30. By adding the insulating layer, problems such as electrical short - circuit phenomena and fire caused by contact between the cell and the case due to impacts that may occur during use can be prevented. The insulating layer can be formed using an insulating sheet having high insulation and thermal conductivity, or can be formed by coating or injecting a substance exhibiting insulation properties. For example, a process of forming the insulating layer can be performed before injecting the two - component resin composition. For forming the insulating layer, so - called TIM (Thermal Interface Material) etc. may be applied. In another method, the insulating layer can be formed of an adhesive substance. For example, an insulating layer may be formed using a resin layer with little or no filler content such as a thermally conductive filler. Examples of resin components that can be used for forming the insulating layer include acrylic resin, PVC (poly(vinyl chloride)), olefin resins such as PE (polyethylene), epoxy resin, silicon, and rubber components such as EPDM rubber (ethylene propylene diene monomer rubber), but are not limited thereto. The insulating layer may have a breakdown voltage measured in accordance with ASTM D149 of about 5 kV / mm or more, 10 kV / mm or more, 15 kV / mm or more, 20 kV / mm or more, 25 kV / mm or more, or about 30 kV / mm or more. The higher the value of the breakdown voltage, the better the insulation performance, and it is not particularly limited. For example, the breakdown voltage of the insulating layer may be about 100 kV / mm or less, 90 kV / mm or less, 80 kV / mm or less, 70 kV / mm or less, or about 60 kV / mm or less. The thickness of the insulating layer can be set within an appropriate range considering the insulation and thermal conductivity of the insulating layer. For example, it may be about 5 μm or more, 10 μm or more, 20 μm or more, 30 μm or more, 40 μm or more, 50 μm or more, 60 μm or more, 70 μm or more, 80 μm or more, or about 90 μm or more.Moreover, the upper limit of the thickness is not particularly limited, and for example, it may be about 1 mm or less, about 200 μm or less, 190 μm or less, 180 μm or less, 170 μm or less, 160 μm or less, or about 150 μm or less.

[0119] Further, the present application relates to a battery pack, for example, a battery pack including two or more of the above-described battery modules. In the battery pack, the battery modules may be electrically connected to each other. The method of electrically connecting two or more battery modules to form a battery pack is not particularly limited, and any known method can be applied.

[0120] Further, the present application relates to an apparatus including the battery module or the battery pack. Examples of the apparatus include automobiles such as electric vehicles, but are not limited thereto, and all applications requiring a secondary battery output may be included. For example, the method of configuring the automobile using the battery pack is not particularly limited, and a general method can be applied.

Advantages of the Invention

[0121] The present application can provide a resin composition excellent in one or more properties selected from thermal conductivity, adhesiveness, insulating properties, tensile properties, hardness, and flame retardancy, a method for producing the same, and uses thereof, while ensuring excellent thixotropy.

Brief Description of the Drawings

[0122]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0123] Hereinafter, the present application will be described by way of specific examples through embodiments, but the scope of the present application is not limited by the following embodiments.

[0124] 1. Particle Size Distribution The particle size distribution of the particles (FR-119L) applied in the examples was evaluated by a laser analysis method. As the measuring equipment, a particle size distribution analyzer (PSA) (Model Mastersizer 300, Malvem Instruments LTD) was applied and evaluated by a standard method. In the above method, a laser is used, and the incident laser is scattered, transmitted, and absorbed by the particles. Among these, in the scattered light, there is light that is diffracted, refracted, and reflected. In some cases, a part of the absorbed light may be emitted as light of other wavelengths. Such phenomena occur simultaneously and complexly, but in the standard method using the above measuring equipment, the degree of the light scattering is detected, and through this, the particle size distribution is measured. The measuring methods include a wet method in which particles are dispersed in a solvent for measurement and a dry method in which measurement is performed in a powder state. In the present application, the wet method was applied. As the solvent, ethanol was applied, and the dispersion concentration was set within a range of approximately 1 to 5% by weight.

[0125] 2. Evaluation of Particle Size Distribution after Milling The particles (FR-119L) applied in the examples and zirconia beads with a diameter of 1 mm were dispersed in ethanol and then milled by shaking at a speed of 200 RPM. The milling was carried out for 20 hours, and during mixing, the total volume of the zirconia beads was mixed so as to be at a level of about 1 / 3 compared to the total volume of the flame retardant. After the above milling, washing was performed with ethanol to separate the zirconia beads, and then the particle size distribution of the particles was measured by the same method as described above.

[0126] 3. Viscosity of the resin composition The viscosity of the resin composition can be measured using a HB type viscometer. Measure while changing the shear rate from 0.01 / s to 10.0 / s with the HB type viscometer described above. Unless otherwise specified, the viscosity value is the value at a shear rate of 2.5 / s, and the thixotropy index is the ratio of the viscosities at the 0.1 / s point and the 1.0 / s point.

[0127] <Example 1> The specific details of the components applied during the production of the resin composition are organized below, and the method of producing the resin composition using these is as follows. Mixing in the following production method was carried out using a Planetary mixer. Also, in the following production method, the curable resin is divided and added in a total of 3 times. When the amount of the curable resin present in the final resin composition is 100 parts by weight, the weight ratios added at the time of the first, second, and third curable resin additions are approximately 50 - 55:25:25 - 20 (first:second:third). Also, in the following, the alumina filler is mixed at approximately 900 parts by weight with respect to 100 parts by weight of the total curable resin component. At this time, the weight ratios of the alumina fillers with average particle diameters (D50) of approximately 2μm, 20μm, and 40μm are made to be approximately 3:3:4 (2μm:20μm:40μm).

[0128] First, as the first step, it was mixed with the following curable resin and a catalytic amount of catalyst (addition of the first curable resin). Then, the following dispersant and liquid flame retardant were mixed with the mixture in appropriate ratios.

[0129] Then, a spherical alumina filler (first heat conductive filler) with an average particle diameter (D50) of approximately 2μm and the following particles (FR - 119L) were mixed with the mixture. The above particles (FR - 119L) were mixed in an amount of about 15 parts by weight.

[0130] Then, a mixture of the same curable resin as that contained in the mixture and a spherical alumina filler (second heat conductive filler) with an average particle diameter (D50) of approximately 20μm was additionally mixed with the mixture (addition of the second curable resin).

[0131] Subsequently, a mixture of a curable resin identical to that contained in the above mixture and spherical alumina fillers (third thermal conductivity fillers) with an average particle size (D50) of approximately 40 μm was additionally mixed into the above mixture (addition of the tertiary curable resin), and vacuum degassing was performed to produce a resin composition.

[0132] The viscosity of the resin composition produced as described above at room temperature (based on a shear rate of 2.5 / s) was approximately 230,000 kcP, and the thixotropy index was approximately 2.

[0133] <Components of the resin composition>

[0134] Curable resin: A polyol compound obtained by subjecting butanediol and caprolactone to an ester reaction at a weight ratio of 1:2.78 (butanediol:caprolactone)

[0135] Catalyst: DBTDL (dibutyltin dilaurate) (produced by Matsubara Sangyo, TL-100)

[0136] Dispersant: DISPERBYK-111 (manufactured by BYK)

[0137] Liquid flame retardant: Liquid phosphorus-based flame retardant (manufactured by Oceanchem, resorcinol bis(diphenyl phosphate))

[0138] Particles: Particulate phosphorus-based flame retardant Agent( X-Guard FR-119L)

[0139] The change in the particle size distribution of the above particles before and after the above-described milling was tabulated in Table 1 below, and such a particle size distribution change curve is shown in FIG. 6. In FIG. 6, the arrow direction indicates the direction from the curve before the milling to the curve after the milling.

[0140]

Table 1

[0141] <Comparative Example 1>

[0142] A resin composition was produced in the same manner as in Example 1 except that no particles were applied. In this case, the thixotropy index at the initial stage of production was approximately 1, with almost no thixotropy, and over time, due to sedimentation of the filler and the like, uniform mixing of the curable resin and the filler was not achieved.

Claims

1. A curable resin; Particles; and A thermally conductive filler, wherein the curable resin contains a polyol compound, the particles are flame retardant particles, the thermally conductive filler contains ceramic particles, the flame retardant particles are contained in a ratio of 5 to 30 parts by weight with respect to 100 parts by weight of the curable resin, the thermally conductive filler is contained in a ratio of 300 parts by weight or more with respect to 100 parts by weight of the curable resin, the flame retardant particles are particles obtained by mixing zirconia beads having a particle size of 1 mm and the flame retardant particles with ethanol so that the total volume of the zirconia beads becomes 1 / 3 of the total volume of the flame retardant particles, and milling by shaking at a speed of 200 RPM for 20 hours, and the change rate of the D50 particle size is in the range of -95% to -80%, the flame retardant particles have a D50 particle size in the range of 1 to 10 μm, the thixotropic index value is 1.2 or more, The thixotropic index value is the ratio of the viscosity (V ０.１ ) at a shear rate of 0.1 / s to the viscosity (V １.０ ) at a shear rate of 1.0 / s (V ０.１ / V １.０ ), and the viscosities V0.1 and V1.0 are viscosities measured at 25°C, and it is a resin composition.

2. The resin composition according to claim 1, wherein the flame retardant particles are particles obtained by mixing zirconia beads having a particle size of 1 mm and the flame retardant particles with ethanol so that the total volume of the zirconia beads becomes 1 / 3 of the total volume of the flame retardant particles, and milling by shaking at a speed of 200 RPM for 20 hours, and the change rate of the D10 particle size is in the range of -85% to -70%.

3. The resin composition according to claim 1, wherein the flame retardant particles are particles obtained by mixing zirconia beads having a particle size of 1 mm and the flame retardant particles with ethanol so that the total volume of the zirconia beads becomes 1 / 3 of the total volume of the flame retardant particles, and milling by shaking at a speed of 200 RPM for 20 hours, and the change rate of the D90 particle size is in the range of -95% to -80%.

4. The resin composition according to claim 1, wherein the ratio (D90 / D50) of the D50 particle size to the D90 particle size of the flame retardant particles is in the range of 1.5 to 5.

5. The resin composition according to claim 1, wherein the ratio (D50 / D10) of the D50 particle size to the D10 particle size of the flame retardant particles is in the range of 3.5 to 6.

6. The resin composition according to any one of claims 1 to 5, wherein the thermally conductive filler includes a first filler having an average particle diameter in the range of 1 μm to 3 μm, a second filler having an average particle diameter in the range of 15 μm to 25 μm, and a third filler having an average particle diameter in the range of 35 μm to 200 μm.

7. The resin composition according to any one of claims 1 to 6, wherein the thixotropic index value is 1.2 to 4.

8. The resin composition according to any one of claims 1 to 7, further comprising a curing agent for the curable resin.

9. A method for producing a resin composition, comprising the step of mixing a curable resin; particles and a thermally conductive filler, wherein the curable resin includes a polyol compound, the particles are flame retardant particles, the flame retardant particles have a D50 particle diameter in the range of 1 to 10 μm, the thermally conductive filler includes ceramic particles, the flame retardant particles are mixed at a ratio of 5 to 30 parts by weight based on 100 parts by weight of the curable resin, the thermally conductive filler is mixed at a ratio of 300 parts by weight or more based on 100 parts by weight of the curable resin, the flame retardant particles are particles obtained by mixing zirconia beads having a particle diameter of 1 mm and the flame retardant particles with ethanol so that the total volume of the zirconia beads is at a level of 1 / 3 of the total volume of the flame retardant particles, and milling by shaking at a speed of 200 RPM for 20 hours, and the change rate of the D50 particle diameter is in the range of -95% to -80%, the resin composition has a thixotropic index value of 1.2 or more, the thixotropic index value is the ratio (V 0.1 / V 1.0 ) of the viscosity (V 0.1 ) at a shear rate of 0.1 / s to the viscosity (V 1.0 ) at a shear rate of 1.0 / s, the viscosities V 0.1 and V 1.0 are the viscosities measured at 25°C, a method for producing a resin composition.

10. a first step of forming a mixture of the curable resin or a curing agent for the resin; the particles and the thermally conductive filler; and a second step of mixing the mixture of the first step with a thermally conductive filler having an average particle diameter larger than that of the thermally conductive filler of the first step, the method for producing a resin composition according to claim 9.

11. A module case having an upper plate, a lower plate, and side walls, with an internal space formed by the upper plate, the lower plate, and the side walls; A plurality of battery cells present in the internal space of the module case; and A battery module including the resin composition according to any one of claims 1 to 8 and including a resin layer in contact with the plurality of battery cells and the lower plate or the side walls.

12. A battery pack including two or more of the battery modules according to claim 11, which are electrically connected to each other.

13. An automobile including the battery pack according to claim 12.

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