Heat-absorbing pad

Abstract

The present application relates to a heat-absorbing pad. The heat-absorbing pad of the present application has a porous structure and can exhibit excellent heat-absorbing and thermal transfer delay characteristics. The heat-absorbing pad can be effectively used to delay the transfer of heat to adjacent battery cells in the event of thermal runaway in a battery cell.

Description

heat absorption pad

[0001] The present application relates to a heat-absorbing pad. The present application claims the benefit of priority based on Korean Patent Application No. 10-2024-0130012 filed September 25, 2024, and all contents disclosed in the document of said Korean patent application are incorporated herein as part of the specification.

[0002] Thermal runaway in batteries occurs when the thermal stability of internal chemical substances exceeds its limits, causing the cell to rapidly release internal energy to the outside. It is defined as a drop in the cell's measured voltage, a measured temperature of dT / dt ≥ [4℃ / s], and a maximum operating temperature (approximately 120℃). Causes of thermal runaway include overcharging, collisions / drops, heat exposure, exposure to high voltage / current, and external / internal short circuits. Once thermal runaway begins, the battery's internal pressure increases, and flammable materials are ejected, leading to ignition. Subsequently, the fire heats adjacent cells and spreads rapidly. Although battery fires are classified as electrical fires and gas-based fire suppression systems are currently applied, battery modules are protected by metal covers, making it difficult for extinguishing agents to penetrate. Furthermore, since temperatures can rise to 1000℃ in a short period during thermal runaway, the release of extinguishing agents must occur at the very beginning of the fire. Therefore, to stop thermal runaway, sufficient cooling or complete combustion in the early stages of the fire is the ultimate means of extinguishment.

[0003] Phase Change Materials (PCMs) are materials that provide heat and cooling by releasing and absorbing energy through phase transitions. The latent heat generated by a phase transition is higher than general sensible heat, and the material converts from a solid or liquid state to another state, storing and releasing a large amount of energy at the Phase Change Temperature (PCT). Phase Change Materials are used in fields requiring energy storage and stable temperatures, such as heating pads, cooling devices, and clothing (Patent Document 1: Korean Patent Publication No. 10-2020-0107214).

[0004] The present application relates to a heat-absorbing pad. The heat-absorbing pad of the present application has a porous structure and can exhibit excellent heat-absorbing performance and excellent heat transfer delay characteristics. The heat-absorbing pad can be usefully used to delay heat transfer to adjacent battery cells during thermal runaway of a battery cell.

[0005] The present application relates to a heat-absorbing pad. The present application also relates to a resin composition. The resin composition may be for manufacturing the heat-absorbing pad. The heat-absorbing pad may have the property of absorbing heat generated from the surroundings. The heat-absorbing pad may include a heat-absorbing material and a binder resin. The heat-absorbing pad may include a resin composition comprising a heat-absorbing material and a binder resin in a cured state. That is, the heat-absorbing pad may include a cured product of the resin composition. The heat-absorbing pad may be the cured product of the resin composition itself. If additional layers other than the cured product of the resin composition are included, it may be referred to as a multilayer heat-absorbing pad.

[0006] Among the physical properties mentioned in this specification, those properties in which the measurement temperature and / or measurement pressure affects the result are, unless specifically stated otherwise, results measured at room temperature and / or atmospheric pressure. In this specification, the term "room temperature" refers to a natural temperature that has not been heated or cooled, and is typically a temperature within the range of about 10°C to 30°C, a temperature within the range of 20°C to 30°C, or about 23°C or about 25°C. In this specification, the unit of temperature is °C unless specifically defined otherwise. In this specification, the term "atmospheric pressure" refers to a natural pressure that has not been pressurized or depressurized, and typically means about 1 atmosphere, which is the level of atmospheric pressure. In this specification, physical properties in which the measurement humidity affects the result are, unless specifically defined otherwise, properties measured at natural humidity that has not been separately controlled under the above room temperature and atmospheric pressure conditions.

[0007] In this specification, an endothermic material may refer to a material that absorbs or consumes heat generated from the surroundings. An endothermic material may spontaneously undergo thermal decomposition or generate new materials by utilizing the absorbed thermal energy.

[0008] The above-mentioned endothermic material may undergo an irreversible endothermic reaction. That is, the above-mentioned endothermic material may be a substance that reacts irreversibly when heated and cooled. In one example, the above-mentioned endothermic material undergoes thermal decomposition through endothermy when the ambient temperature rises, and does not return to the state of the endothermic material prior to thermal decomposition even when the ambient temperature drops. This irreversibility can be advantageous for exhibiting excellent heat transition delay characteristics. On the other hand, paraffin, a representative phase change material (PCM), absorbs heat and melts into a liquid state when the ambient temperature rises, and releases heat to return to a solid state when the ambient temperature drops. The above-mentioned phase change material is a substance that reacts reversibly through endothermy and exothermy. The above-mentioned resin composition may not contain a phase change material that reacts reversibly as described above.

[0009] In one example, the thermal deposition temperature of the endothermic material may be 50°C or higher. The thermal deposition temperature of the endothermic material may be 300°C or lower. The thermal deposition temperature may also be referred to as the temperature at which the endothermic material undergoes an endothermic reaction (endothermic reaction temperature). The thermal decomposition may mean that when heat is applied to a substance, it chemically decomposes into a simpler substance. The thermal decomposition temperature may refer to the temperature at which the thermal decomposition occurs. The thermal decomposition temperature of the endothermic material may be 300°C or lower, 280°C or lower, 260°C or lower, 240°C or lower, 220°C or lower, 200°C or lower, 180°C or lower, 160°C or lower, 140°C or lower, 120°C or lower, or 100°C or lower. The thermal decomposition temperature of the above-mentioned endothermic material may specifically be 50°C or higher, 60°C or higher, 70°C or higher, 80°C or higher, 90°C or higher, 100°C or higher, 120°C or higher, 140°C or higher, 160°C or higher, or 180°C or higher. When the endothermic material is heated to the above-mentioned thermal decomposition temperature, it may decompose into the components constituting the endothermic material through endothermic reaction. If the thermal decomposition temperature of the endothermic material is within the above range, there is no or minimal endothermic reaction at the normal operating temperature of the battery, and if thermal runaway of the battery occurs, it may be advantageous in that it can provide a cooling effect to the ignited battery cell through the endothermic reaction (e.g., thermal decomposition) of the endothermic material and delay heat transfer to adjacent battery cells. The above-mentioned thermal decomposition temperature may be a value measured while increasing the temperature at a rate of 10°C / min using a differential scanning calorimeter (DSC Q2000, TA). A graph can be obtained from a differential scanning calorimeter with the x-axis representing temperature (°C) and the y-axis representing heat flow (W / g), and the temperature at the point where the absolute value of the heat flow (W / g) is maximum in the graph can be set as the pyrolysis temperature.

[0010] In one example, the endothermic substance may be a water-soluble substance. The water-soluble substance may refer to a substance having a solubility in water at 20°C greater than 0 g / 100 ml. In one example, the solubility of the endothermic substance in water at 20°C may be 4.5 g / 100 ml or more. Specifically, the solubility of the endothermic substance in water may be 5 g / 100 ml or more, 10 g / 100 ml or more, 15 g / 100 ml or more, 20 g / 100 ml or more, 25 g / 100 ml or more, 30 g / 100 ml or more, 35 g / 100 ml or more, or 40 g / 100 ml or more. The upper limit of the solubility of the endothermic substance in water may be, for example, 50 g / 100 ml or less. The above solubility can be determined by adding 1g of the endothermic substance to 100ml of water at a temperature of 20℃ and measuring the weight of the endothermic substance until a precipitate is formed.

[0011] In one example, the endothermic material may have thermal conductivity. In one example, the thermal conductivity (λ) of the endothermic material may be 20 W / mK or less. If the thermal conductivity of the endothermic material is within the above range, it may be advantageous for exhibiting excellent heat transfer delay characteristics. Specifically, the thermal conductivity of the endothermic material may be 15 W / mK or less, 10 W / mK or less, 5 W / mK or less, 4 W / mK or less, 3 W / mK or less, 2 W / mK or less, 1 W / mK or less, or 0.5 W / mK or less. The lower limit of the thermal conductivity of the endothermic material may be, for example, 0.001 W / mK or more. The thermal conductivity (λ) is a value defined by thermal diffusivity (α) × specific heat (Cp) × density (ρ). The thermal conductivity (λ) may be a value measured at a temperature of 25°C. The thermal conductivity of an endothermic material can be measured using known thermal conductivity measuring equipment. Alternatively, the thermal conductivity of an endothermic material is largely known, and an endothermic material satisfying the above thermal conductivity can be used.

[0012] In one example, when the endothermic material is thermally analyzed by increasing the temperature from 0°C to 350°C at a rate of 10°C / min using a differential scanning calorimeter, the endothermic peak temperature may be less than 200°C. In this specification, the endothermic peak temperature may refer to the temperature at the point where the absolute value of Heat Flow (W / g) is highest in a graph of Heat Flow (W / g) (y-axis) against Temperature (°C) (x-axis) obtained through thermal analysis using a differential scanning calorimeter. The endothermic peak temperature may be, for example, 50°C or higher. If the endothermic peak temperature is within the above range, it may be advantageous for exhibiting excellent heat transfer characteristics. Specifically, the above endothermic peak temperature may be 190°C or lower, 180°C or lower, 170°C or lower, 160°C or lower, 150°C or lower, 140°C or lower, 130°C or lower, 120°C or lower, 110°C or lower, or 100°C or lower, and may be 60°C or higher, 70°C or higher, 80°C or higher, 90°C or higher, 100°C or higher, 110°C or higher, 120°C or higher, 130°C or higher, 140°C or higher, 150°C or higher, 160°C or higher, 170°C or higher, 180°C or higher, or 190°C or higher.

[0013] In one example, the endothermic material may have a single endothermic peak (one endothermic peak) at a temperature below 200°C. In another example, the endothermic material may have dispersed endothermic peaks (two or three or more endothermic peaks) at a temperature below 200°C. Having two or three or more endothermic peaks may mean having one endothermic peak with the highest absolute value of Heat Flow (W / g) and one or two or more additional endothermic peaks with the next highest absolute value of Heat Flow (W / g). Assuming the amount of heat absorbed is the same, the endothermic material having a single peak may have superior heat transfer delay characteristics. Examples of endothermic substances having a single peak include AlCl3·6H2O, MgSO4·7H2O, NiSO4·6H2O, Na4P2O7·10H2O, Sr(OH)2·8H2O, CaSO4·2H2O, etc.

[0014] In one example, the endothermic material may have an endothermic amount of 500 J / g or more. In this specification, the endothermic amount may refer to the total sum of heat (integral value on the DSC graph) from the point at which endothermic reaction begins to the point at which endothermic reaction ends. Specifically, the endothermic amount can be obtained by calculating the area of ​​the graph of the endothermic region (by integrating the graph of the endothermic region) on a graph of Heat Flow (W / g) (y-axis) against Temperature (°C) (x-axis) obtained through thermal analysis with a differential scanning calorimeter. The endothermic region may refer to the interval from the endothermic initiation temperature to the endothermic termination temperature on the graph. The area may refer to the area of ​​a closed curve formed by a straight line (A) connecting the graph point at the endothermic initiation temperature and the graph point at the endothermic termination temperature, and a continuous graph (B) of the interval from the endothermic initiation temperature to the endothermic termination temperature. If the endothermic amount at the endothermic peak is within the above range, it may be advantageous for exhibiting excellent heat transfer characteristics. Specifically, the above heat absorption amount may be 600 J / g or more, 700 J / g or more, 800 J / g or more, 900 J / g or more, 1,000 J / g or more, 1,100 J / g or more, 1,200 J / g or more, 1,300 J / g or more, 1,400 J / g or more, 1,500 J / g or more, 1,600 J / g or more, or 1,700 J / g or more, and may be 2,000 J / g or less. The above heat absorption amount may be a value measured while increasing the temperature at a rate of 10℃ / min using a differential scanning calorimeter (DSC Q2000, TA).

[0015] The endothermic material may include hydrate particles and / or solid acid particles. The resin composition and / or the endothermic pad may include hydrate particles as the endothermic material, or include solid acid particles, or include both hydrate particles and solid acid particles.

[0016] In one example, the endothermic substance may be a hydrate particle. The hydrate particle may refer to a particle containing water molecules (H2O). When a hydrate particle is applied as the endothermic substance, water molecules may be dissociated from the endothermic substance by thermal decomposition. This may be advantageous for exhibiting excellent thermal transfer delay characteristics. Specifically, the hydrate particle may be an inorganic salt containing water molecules bonded to the crystal of a metal compound. The water contained in the hydrate particle may be referred to as crystal water. The hydrate particle is different from a hydroxide particle, which may refer to a substance containing -OH (-hydroxyl group) without containing H2O.

[0017] In one example, the hydrate particles are (Mg(H2PO4)2)·8H2O, MgCl2·6H2O, AlCl3·6H2O, Na4P2O7·10H2O, KAl(SO4)2·12H2O, NiSO4·6H2O, Mg(NO3)2·6H2O, CoSO4·7H2O, (NH4)2Fe(SO4)2·6H2O, CuSO4·5H2O, ZnSO4·7H2O, CoCl2·6H2O, CrCl3·6H2O, NiCl2·6H2O, MgSO4·7H2O, Al2(SO4)3·18H2O, Na2B4O7·10H2O, Sr(OH)2·8H2O, CaC2O4·H2O, Ba(OH)2·8H2O, It may include one or more particles selected from the group consisting of Ba(OH)2·H2O, Mg3(PO4)2·5H2O, Mg3(PO4)2·8H2O and FeSO4·7H2O.

[0018] In one example, the endothermic material may be solid acid particles. The solid acid particles may refer to solid acid particles that exist in a solid state at room temperature (about 25°C). When a solid acid is applied as the endothermic material, excellent heat transfer delay characteristics may be exhibited. As the solid acid, a solid acid that undergoes an irreversible endothermic reaction may be used. In one example, the solid acid particles may include one or more particles selected from the group consisting of stearic acid, palmitic acid, boric acid, oxalic acid, tartaric acid, citric acid, and maleic acid.

[0019] In another example, the endothermic material may be a water microcapsule. The microcapsule may comprise a capsule portion and water contained within the capsule portion. The capsule portion may comprise one or more selected from the group consisting of poly(vinyl alcohol), poly(ethylene oxide), polyethylene glycol, poly(methyl methacrylate), butyl acrylate, and silicate. The size of the microcapsule may be, for example, in the range of 50 µm to 500 µm.

[0020] The content of the endothermic material may be appropriately selected within a range that does not impair the purpose of the present application. In one example, the endothermic material may be included in a range of 50 to 500 parts by weight relative to 100 parts by weight of binder resin. Specifically, the endothermic material may be included in an amount of 50 parts by weight or more, 100 parts by weight or more, 150 parts by weight or more, 200 parts by weight or more, 250 parts by weight or more, 300 parts by weight or more, 350 parts by weight or more, or 400 parts by weight or more, relative to 100 parts by weight of binder resin, and may be included in an amount of 500 parts by weight or less, 450 parts by weight or less, 400 parts by weight or less, 350 parts by weight or less, 300 parts by weight or less, 250 parts by weight or less, or 250 parts by weight or less. An endothermic pad in which the content of the endothermic particles is within the above range is suitable for production and may be advantageous for exhibiting excellent heat transfer delay characteristics.

[0021] The binder resin may include silicone resin. When silicone resin is used as the binder resin, it may be advantageous for exhibiting excellent heat transfer delay characteristics. In particular, even when an endothermic material containing water is used as the endothermic material, excellent heat transfer delay characteristics can be exhibited because no changes over time or water generation occur after the binder resin and the endothermic material are combined. Meanwhile, organic materials such as urethane resin or epoxy resin burn up in a flame, whereas in the case of silicone resin, the Si-O-Si siloxane chains change into SiO2 by heat, so it may have better resistance to flame.

[0022] In one example, the silicone resin may include a silicone resin having vinyl groups at both ends (which may be referred to as silicone vinyl resin). The silicone vinyl resin may be a polydimethylsiloxane having vinyl groups at both ends. In another example, the silicone resin may include a silicone resin having hydroxyl groups at both ends (which may be referred to as silicone hydroxy resin). The silicone hydroxy resin may be a polydimethylsiloxane having hydroxyl groups at both ends. The resin composition may include silicone vinyl resin, silicone hydroxy resin, or a mixture of silicone vinyl resin and silicone hydroxy resin. The silicone resin having vinyl groups at both ends may be a compound represented by the following Chemical Formula 1. The silicone resin having hydroxyl groups at both ends may be a compound represented by the following Chemical Formula 2. In the following chemical formulas 1 and 2, n can be an integer greater than or equal to 1, and can be appropriately selected considering the molecular weight of the silicone resin below.

[0023] [Chemical Formula 1]

[0024]

[0025] [Chemical Formula 2]

[0026]

[0027] The above binder resin may further include a silicon hydride resin as a silicon resin. The above silicon hydride resin may refer to a silicon polymer having -Si-H groups. The -Si-H groups of the silicon hydride resin may react with the vinyl groups of the silicon vinyl resin. Additionally, the -Si-H groups of the silicon hydride resin may react with the hydroxyl groups of the silicon hydroxy resin. Such silicon hydride resins can act as crosslinkers in the binder resin to improve the crosslinking density. If differentiation is required, the silicon vinyl resin and silicon hydroxy resin may be referred to as the main components, and the silicon hydride resin may be referred to as a curing agent or a crosslinking agent. For example, when the above resin composition is used as a two-component resin composition, two mixtures can be prepared by separating the silicon hydride resin and the catalyst. At this time, a formulation containing at least a silicone hydride resin without a catalyst may be referred to as a curing agent formulation, and a formulation containing a catalyst and including a silicone vinyl resin and / or a silicone hydroxy resin may be referred to as a main component formulation. In the case of a one-component resin composition, since a single formulation is prepared by mixing a silicone resin and a catalyst, the above distinction may not be necessary.

[0028] The above silicone hydride resin has at least one -CH3 of its side chains - It may be a polydimethylsiloxane substituted with H. In one example, the silicone hydride resin may be a polydimethylsiloxane in which at least one -CH3 group of the side chain is substituted with -H and both ends are -CH3 (pendent type). In another example, the silicone hydride resin may be a polydimethylsiloxane in which the -CH3 groups of both ends are substituted with -H and at least one -CH3 group of the side chain is also substituted with -H (hybrid type).

[0029] In one example, a silicone hydride resin may be included in the resin composition such that the H / V ratio is within the range of 1 to 20. H is a value defined as H mmol / g × H wt%, and V is a value defined as V mmol / g × V wt%. In the above, H mmol / g refers to the mmol of Si-H (silicon-hydrogen) per gram of silicone hydride resin included in the resin composition, and V mmol / g refers to the mmol of Si-Vi (silicon-vinyl) per gram of silicone resin included in the resin composition. In the above, H wt% refers to the weight fraction of the silicone hydride resin relative to the weight of the total resin composition, and V wt% refers to the weight fraction of the silicone resin relative to the weight of the total resin composition. In the above, the weight fraction of the total resin composition is 100 wt%.

[0030] The molecular weight of the above silicone resin may be selected within a range that does not impair the purpose of the present application. The molecular weight of the silicone resin refers to the molecular weight of the silicone polymer constituting the silicone resin. In one example, the molecular weight of the silicone resin may be 100,000 g / mol or less. When the molecular weight of the silicone resin is within the above range, the heat resistance performance is improved, which may be more advantageous for exhibiting excellent heat transfer delay characteristics. Specifically, the molecular weight of the above silicone resin may be 90,000 g / mol or less, 80,000 g / mol or less, 70,000 g / mol or less, 60,000 g / mol or less, 50,000 g / mol or less, 40,000 g / mol or less, 30,000 g / mol or less, 25,000 g / mol or less, 20,000 g / mol or less, 15,000 g / mol or less, or 10,000 g / mol or less. The lower limit of the molecular weight of the above silicone resin may be 100 g / mol or more, 500 g / mol or more, or 1,000 g / mol from the perspective of handling the fabricated pad.

[0031] The viscosity of the silicone resin may be selected within a range that does not impair the purpose of the present application. In one example, the viscosity of the silicone resin may be 150,000 cSt or less. When the viscosity of the silicone resin is within the above range, it may be more advantageous to exhibit excellent heat transfer delay characteristics. The viscosity of the silicone resin may be 100,000 cSt or less, 50,000 cSt or less, or 10,000 cSt or less. Specifically, the viscosity of the above silicone resin may be less than 10,000 cSt, 9,000 cSt or less, 8,000 cSt or less, 7,000 cSt or less, 6,000 cSt or less, 5,000 cSt or less, 4,500 cSt or less, 4,000 cSt or less, 3,500 cSt or less, 3,000 cSt or less, 2,500 cSt or less, 2,000 cSt or less, 1,500 cSt or less, or 1,000 cSt or less. Regarding the viscosity of the silicone resin, for commercially available products, information on viscosity is provided by the seller. Therefore, a silicone resin product satisfying the above viscosity can be selected and used, and the viscosity measurement conditions can also follow those provided by the silicone resin seller. In one example, viscosity in cSt units can be measured using a Canon-Fenske Viscomete. The method for measuring viscosity using a Canon-Fenske viscometer is known. For example, cSt viscosity can be calculated from Efflux time x Viscometer Factor. Efflux time refers to the time it takes for a sample (relative to the top surface of the fluid) to descend from a specific upper mark to a specific lower mark due to gravity after filling the viscometer with the sample. At this time, the viscometer filled with the sample can be placed in a constant temperature water bath to allow the sample to reach the temperature to be measured, and then the time can be measured.The above temperature may be, for example, a temperature within the range of about 10°C to 30°C, about 20°C, or about 25°C. The Viscometer Factor is a coefficient unique to the viscometer at the temperature at which viscosity is to be measured, provided by the manufacturer of the viscometer. If the coefficient is not provided by the manufacturer, the coefficient may be corrected directly using water or other standard liquids.

[0032] In one example, the resin composition may not include an amine compound and / or an isocyanate compound. The amine compound and / or isocyanate compound may not be suitable for formulation with the endothermic material. The amine compound may be a curing agent when using an epoxy resin as a binder resin, and the isocyanate compound may be a curing agent when using a polyol resin to a urethane resin as a binder resin. According to the present application, the epoxy resin, polyol resin and / or urethane resin may not be included as a binder resin.

[0033] The resin composition may further include a catalyst. The catalyst may promote the reaction of the silicon hydride resin in the binder resin. In one example, the catalyst may promote the hydrosilylation addition reaction between the carbon-carbon double bond of the silicon vinyl resin and the -SiH group of the silicon hydride resin. In another example, the catalyst may promote the hydrogen condensation reaction between the -Si-OH group of the silicon hydroxy resin and the -Si-H group of the silicon hydride resin. In one example, the catalyst may be a platinum group catalyst. The platinum group catalyst may include a platinum-based metal catalyst, a palladium-based metal catalyst, a rhodium-based metal catalyst, or a mixture thereof. In another example, the catalyst may be a metal salt catalyst. The metal salt catalyst may include a tin-based metal salt such as bis(2-ethylhexanoate)tin or dibutyldilauryltin, a zinc-based metal salt such as zinc octoate, an iron-based metal salt such as iron octoate, or a mixture thereof. The above catalyst may be included in a range of 0.01 to 10 parts by weight, 0.01 to 5 parts by weight, 0.01 to 3 parts by weight, 0.01 to 1 part by weight, or 0.01 to 0.5 parts by weight per 100 parts by weight of binder resin.

[0034] The resin composition may further include additives in addition to the binder resin and catalyst. In one example, the resin composition may further include a dispersant. For example, an amino-silicone dispersant may be used as the dispersant. The dispersant may be included in a range of 0.1 to 10 parts by weight, 0.1 to 5 parts by weight, or 0.5 to 5 parts by weight per 100 parts by weight of the binder resin.

[0035] In one example, the resin composition may further comprise a chain extender. As the chain extender, for example, a compound having -SiH (silicon-hydride) at both ends may be used. The -SiH may react with the vinyl groups of the silicone resin. In one example, the chain extender may be a polydimethylsiloxane in which -CH3 at both ends are substituted with -H and the side chain is -CH3. When the resin composition comprises both a silicone hydride resin and a chain extender, the silicone hydride resin and the chain extender may be included in the resin composition such that the H / V ratio is within the range of 1 to 20. H is a value defined as (H1 mmol / g ≠ H1 wt% + H2 mmol / g ≠ H2 wt%), and V is a value defined as V mmol / g ≠ V wt%. In the above, H1 mmol / g refers to the mmol of Si-H (silicon-resin) per gram of silicon hydride resin included in the resin composition, H2 mmol / g refers to the mmol of Si-H (silicon-resin) per gram of chain extender included in the resin composition, and V mmol / g refers to the mmol of Si-Vi (silicon-vinyl) per gram of silicon resin included in the resin composition. In the above, H1 wt% refers to the weight fraction of silicon hydride resin relative to the weight of the total resin composition, H2 wt% refers to the weight fraction of chain extender relative to the weight of the total resin composition, and V wt% refers to the weight fraction of silicon resin relative to the weight of the total resin composition. In the above, the weight fraction of the total resin composition is 100 wt%.

[0036] In one example, the resin composition may further include a curing retardant. The curing retardant may be, for example, a compound having a carbon-carbon double bond or a carbon-carbon triple bond. The above-mentioned curing retardant is 1-ethynyl-1-cyclohexanol, 3-methyl-1-pentene-3-ol, 2-methyl-3-butyn-2-ol, 3-phenyl-3-butyn-2-ol, 2-phenyl-3-butyn-2-ol, 3,5-dimethyl-1-hexine-3-ol, 1,5-hexadiine, 1,6-heptadiine, 3,5-dimethyl-1-hexine, 2-ethyl-3-butine, 2-phenyl-3-butine, 1,3-divinyltetramethyldisiloxane, 1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane, 1,3-divinyl-1,3-diphenyldimethyldisiloxane, 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane and It may be one or more selected from the group consisting of divinyl-1,1,3,3-detramethyldisilazane, but is not limited thereto. The curing retardant may be included in the range of 0.1 to 10 parts by weight, 0.1 to 5 parts by weight, or 0.5 to 5 parts by weight per 100 parts by weight of binder resin.

[0037] In one example, the resin composition may further include a flame retardant. The flame retardant may be a solid flame retardant in the form of a filler or a liquid flame retardant. Liquid flame retardants may be suitably used when the amount of filler filled into the resin composition is large; for example, TEP, TCPP, etc. described below are representative liquid flame retardants. The flame retardant may include organic flame retardants, inorganic flame retardants, and / or organic-inorganic composite flame retardants. Organic flame retardants may include phosphorus-based flame retardants and / or melamine-based flame retardants. Inorganic flame retardants may include metal hydroxide-based flame retardants. Organic-inorganic composite flame retardants may include phosphorus-metal-based flame retardants.

[0038] In one example, the flame retardant may include one or more selected from the group consisting of: phosphorus-based flame retardants including ammonium polyphosphate (APP), red phosphorus, tris(2-chloroethyl) phosphate (TCEP), isopropylphenyl diphenyl phosphate (IPDP), tris(1-chloro-2-propyl) phosphate (TCPP), triphenyl phosphate (TPP), and triethyl phosphate (TEP); melamine-based flame retardants including melamine cyanurate; metal hydroxide-based flame retardants including aluminum hydroxide and magnesium hydroxide; and organic-inorganic composite flame retardants including aluminum diethyl phosphinate. According to one embodiment of the present application, the flame retardant may include a phosphorus-based flame retardant and a metal hydroxide flame retardant.

[0039] In one example, a coating layer may be present on the surface of the flame retardant. The coating layer may be appropriately selected considering the function to be added to the flame retardant. The coating layer may include, for example, one or more selected from the group consisting of a silicone-based coating layer, an epoxy-based coating layer, and a melamine-based coating layer. As a specific example, if the APP flame retardant has the coating layer, it may exhibit superior water resistance.

[0040] In one example, the flame retardant may be included in a range of 10 to 300 parts by weight, 10 to 200 parts by weight, or 30 to 150 parts by weight per 100 parts by weight of binder resin.

[0041] In one example, the resin composition may further include a flame retardant adjuvant. The flame retardant adjuvant is an additive that can be added to the resin composition along with the flame retardant to further improve the flame retardancy of the resin composition, and may include, for example, PTFE (Polytetrafluoroethylene). When the resin composition further includes the flame retardant, it may be advantageous in terms of improving the heat transfer delay time, suppressing crack formation due to flame, and reducing the final adiabatic temperature.

[0042] The resin composition may further include a foaming agent. The foaming agent may refer to a material included in the resin composition of the present invention that forms pores by generating outgas, thereby providing a heat-absorbing pad with a porous structure.

[0043] The foaming agent may generate outgas at high temperatures (when heated). In one example, the foaming agent may generate outgas at temperatures within the range of about 40°C to 200°C. Specifically, the temperature may be 40°C or higher, 50°C or higher, 60°C or higher, 70°C or higher, or 80°C or higher, and 200°C or lower, 190°C or lower, 180°C or lower, 170°C or lower, 160°C or lower, or 150°C or lower.

[0044] The above outgas may include, for example, CO2, H2O, or H2. The above heat absorption pad is such as CO2, H2O, or H2. It may contain pores originating from outgas with a small molecular weight. Therefore, since the foaming agent can form fine bubbles, it can form more pores in the heat absorption pad.

[0045] In one example, the blowing agent may be a foam particle. If the blowing agent is a foam particle, CO2 or as an outgas. Pores can be formed by generating H2O. The foamed particles may include one or more particles selected from the group consisting of NaHCO3, Na2CO3, KHCO3, and CaCO3. In one example, the foamed particles may spontaneously generate outgas upon heating. Examples of such foamed particles include NaHCO3, KHCO3, and CaCO3. In another example, the foamed particles may generate outgas upon heating by reacting with a solid acid, particularly as an endothermic material. Examples of such foamed particles include Na2CO3.

[0046] In one example, the foaming agent may be a silicone hydroxy resin. The silicone hydroxy resin may refer to a silicone polymer having -Si-OH groups at the ends. In one example, the silicone hydroxy resin may be a polydimethylsiloxane having -Si-OH groups at both ends. The silicone hydroxy resin may react with a silicone hydride resin to form pores. The silicone hydride resin may refer to a silicone polymer having -Si-H groups at the side chains or ends. The -Si-OH groups of the silicone hydroxy resin and the -Si-H groups of the silicone hydride resin may react to leave -Si-O-Si- cross-links and generate H2 gas. The generated H2 gas may form pores in the heat-absorbing pad and cause foaming.

[0047] The above silicone hydroxy resin may be included in the heat-absorbing pad and / or resin composition as the main resin described above, or may be included in the heat-absorbing pad and / or resin composition as a compound distinct from the main resin. The above silicone hydride resin may be included in the heat-absorbing pad and / or resin composition as the curing agent described above, or may be included in the heat-absorbing pad and / or resin composition as a compound distinct from the curing agent.

[0048] In one example, the blowing agent is not a nitrogen (N)-containing compound, nor is it a sulfur (S)-containing compound. Nitrogen (N)-containing compounds or sulfur (S)-containing compounds can strongly adsorb onto the surface of a catalyst, such as platinum, thereby reducing the catalyst's activity. This is because it can delay or hinder the curing of the silicone resin.

[0049] In one example, the content of the foam particles may be appropriately selected in consideration of the purpose of the present application. For example, the foam particles may be included in a range of 1 to 100 parts by weight per 100 parts by weight of binder resin. More specifically, the foam particles may be included in an amount of 1 part by weight or more, 5 parts by weight or more, 10 parts by weight or more, 15 parts by weight or more, 20 parts by weight or more, 25 parts by weight or more, 30 parts by weight or more, 35 parts by weight or more, 40 parts by weight or more, 45 parts by weight or more, or 50 parts by weight or more, per 100 parts by weight of binder resin, and may be included in an amount of 100 parts by weight or less, 90 parts by weight or less, 80 parts by weight or less, 70 parts by weight or less, or 60 parts by weight or less.

[0050] In one example, when the resin composition includes silicone hydroxy resin, the content of silicone hydroxy resin in the weight (100 parts by weight) of the total binder resin (silicone resin) may be in the range of 30 parts by weight to 90 parts by weight.

[0051] In one example, the viscosity of the resin composition may be 500,000 cps or less. When the viscosity of the resin composition is within the above range, it may be advantageous to manufacture an endothermic pad through curing, and the endothermic pad manufactured therefrom may exhibit excellent heat transfer delay characteristics. Specifically, the viscosity of the resin composition may be 450,000 cps or less, 400,000 cps or less, 350,000 cps or less, 300,000 cps or less, 250,000 cps or less, 200,000 cps or less, 150,000 cps or less, or 100,000 cps or less. From the perspective of the pad manufacturing process, the lower limit of the viscosity of the resin composition may be 1,000 cps or more, 5,000 cps or more, 10,000 cps or more, 30,000 cps or more, or 50,000 cps or more. The above viscosity was determined using a Brookfield DV2T HB viscometer at a temperature of 25℃, a rotation speed of 1.2 rpm, and a shear rate (sec -1 ) 2.4, it may be a value measured under the condition of spindle CPA 52Z.

[0052] In one example, the resin composition may be a room-temperature curable resin composition. Accordingly, the resin composition can be cured by maintaining it at room temperature (e.g., about 20°C to 30°C), and separate processes for curing, such as the application of moisture, the application of heat, or irradiation with active energy rays (e.g., ultraviolet rays), may not be required. Furthermore, considering that the resin composition may be used as a heat-absorbing pad containing an endothermic material, it may be more advantageous to be a room-temperature curable type because it may be sensitive to heat that may entail a phase change of the endothermic material. Additionally, the room-temperature curable resin composition may be advantageous when curing must be performed inside a battery. This is because applying heat to the battery for curing inside the battery can be dangerous. Moreover, the room-temperature curable resin composition may be advantageous in that the curing speed can be easily controlled, as it can be cured by applying heat if necessary. In other words, in this specification, a room-temperature curable resin composition means that it can be cured by maintaining it at room temperature, and is not limited to a resin composition that is cured only by maintaining it at room temperature.

[0053] The above-mentioned heat-absorbing pad may have a porous structure. A heat-absorbing pad having a porous structure may be referred to as a heat-absorbing foam pad. In one example, the density of the heat-absorbing foam pad is 1 g / cm³. 3 It may be less than or equal to. The density of the heat-absorbing foam pad is, for example, 0.9 g / cm³ 3 Below, 0.8 g / cm³ 3 Less than or equal to 0.7 g / cm³ 3 It may be less than or equal to. The lower limit of the density of the heat-absorbing foam pad is, for example, 0.2 g / cm³. 3 Above or 0.3 g / cm³ 3 It could be more than that.

[0054] An endothermic pad having a porous structure can be obtained by curing at a high temperature while the resin composition for manufacturing the endothermic pad contains a foaming agent. The endothermic pad does not apply a solvent evaporation method to form a porous structure. Therefore, the endothermic pad and / or the resin composition for manufacturing the endothermic pad may not contain organic solvent components and / or volatile organic compounds for forming a porous structure. In one example, the amount of organic solvent components detected in the endothermic pad during Gas Chromatography-Mass Spectrometry (GC-MS) analysis may be 3 µg / g or less. Specifically, the detected amount may be 2 µg / g or less, 1 µg / g or less, 0.5 µg / g or less, or 0.1 µg / g or less.

[0055] The above organic solvent component may refer to a component with a boiling point within the range of 65°C to 150°C. The above volatile organic compound may refer to a compound having the characteristic of vaporizing at room temperature (e.g., a temperature within the range of about 0°C to 40°C). There is a method of including a solvent component in a resin composition for manufacturing a heat-absorbing pad and evaporating the solvent to provide a heat-absorbing pad having a porous structure, but the porous structure of the heat-absorbing pad may be formed not by the evaporation of the solvent, but by foaming with a foaming agent. In the case of the method of evaporating the solvent, drying must be performed with the top of the resin composition open after applying the resin composition onto a release film, whereas the heat-absorbing pad of the present invention can be provided without such process constraints. Therefore, the heat-absorbing pad of the present invention is advantageous in that it can be manufactured by applying a resin composition between desired substrate films and then curing it.

[0056] An endothermic pad having a porous structure may contain a number of pores inside. In this case, there are no specific restrictions on the shape of the pores; for example, they may be approximately spherical or ellipsoidal, or various other shapes may all be applied.

[0057] The above pores may exist in a state where the interior is empty. The heat-absorbing pad may include two or more layers of pores based on a thickness of 2 mm. The number of pore layers may be, for example, three or more, four or more, or five or more, and the upper limit may be, for example, 10 or fewer layers. The resin composition and / or heat-absorbing pad of the present application may control the number of pore layers of the heat-absorbing pad by controlling the content of the foaming agent or the curing conditions. When controlling the number of pore layers of the heat-absorbing pad, the density of the heat-absorbing pad may be controlled, or the heat transfer delay characteristics may also be controlled. In this specification, the statement that the number of pore layers of the heat-absorbing pad is B or more based on thickness A may mean that when observing the heat-absorbing pad of thickness A in a cross-section parallel to the thickness direction of the heat-absorbing pad, there exists a region in which the number of pores existing in the thickness direction is B.

[0058] In one example, reaction products after foaming of the blowing agent may remain in the heat-absorbing pad. In one example, if NaHCO3 is used as the blowing agent, Na2CO3 may remain or Na2B4O7 and / or NaBO2 may remain. In another example, if Na2CO3 is used as the blowing agent, Na2B4O7 and / or NaBO2 may remain. In another example, if a silicone hydroxy resin is used as the blowing agent, -Si-O-Si- bonds formed by reaction with the silicone hydride resin may be present.

[0059] The heat-absorbing pad described above may have a heat transfer delay effect. In this specification, the heat transfer delay effect may mean that when a flame is radiated onto a single heat-absorbing pad (in a state where no other layer affecting the thermal properties of the heat-absorbing pad is laminated), the heat-absorbing pad absorbs heat and maintains the temperature of the heat-absorbing pad for a certain period without rising. When a heat-absorbing pad having a heat transfer delay effect is applied to a battery cell, the transfer of heat to adjacent battery cells can be effectively delayed even if the battery cell to which the heat-absorbing pad is applied ignites. In this specification, when describing the characteristics of the heat-absorbing pad regarding a flame, the flame may refer to a flame resulting from the combustion of LPG (Liquid Petroleum Gas) or butane gas. The temperature of the flame may be, for example, about 1000°C or higher. The upper limit of the flame temperature may be, for example, 2000°C or lower or 1500°C or lower.

[0060] The fact that the heat-absorbing pad has a heat transfer delay effect may mean that the heat-absorbing pad has a heat transfer delay section. The heat transfer delay section can be defined as a continuous section in which the temperature change is less than 10°C or 5°C or less in a graph of temperature (°C) versus time (seconds) measured while applying a flame to the heat-absorbing pad. The temperature change being less than 10°C or 5°C or less means that the temperature increase per second is less than 10°C or 5°C or less. The heat transfer delay section may be due to the endothermic reaction of the heat-absorbing material. In one example, in a graph of temperature (°C) versus time (seconds) measured while applying a flame to the heat-absorbing pad, a heat transfer delay section may appear after a temperature rise section. In the temperature rise section, the starting temperature (temperature at 0 seconds) is approximately 25°C, and the temperature may increase almost linearly until the start time of the heat transfer delay section. Subsequently, the temperature may remain almost constant in the heat transfer delay section. After the above-mentioned heat transfer delay section, a temperature rise section may appear again. If distinction is necessary, the temperature rise section before the heat transfer delay section may be referred to as the first temperature rise section, and the temperature rise section after the heat transfer delay section may be referred to as the second temperature rise section. After the second temperature rise section, the temperature may converge to a constant temperature again, and this temperature may be referred to as the final adiabatic temperature. The above-mentioned final adiabatic temperature may appear, for example, after about 3 minutes, about 5 minutes, or about 10 minutes have passed since the flame was radiated onto the heat absorption pad.

[0061] In one example, the temperature of the heat transfer delay of the heat-absorbing pad may be 50°C or higher. The temperature of the heat transfer delay may be, for example, 60°C or higher, 70°C or higher, 80°C or higher, 90°C or higher, 100°C or higher, 110°C or higher, 120°C or higher, 130°C or higher, 140°C or higher, 150°C or higher, 160°C or higher, 170°C or higher, 180°C or higher, or 190°C or higher. The lower limit of the above heat transfer delay temperature may be, for example, 300°C or lower, 260°C or lower, 240°C or lower, 220°C or lower, 200°C or lower, 190°C or lower, 180°C or lower, 170°C or lower, 160°C or lower, 150°C or lower, 140°C or lower, 130°C or lower, 120°C or lower, 110°C or lower, or 100°C or lower. The above heat transfer delay temperature may refer to a part of the temperature in the heat transfer delay section (for example, the temperature at the start time and / or the end time of the heat transfer delay section), or it may refer to the temperature over the entire time of the heat transfer delay section. When the heat transfer delay temperature is within the above range, it may be suitable for delaying rapid ignition caused by flames in the early stages by absorbing the initial heat generated when the battery cell explodes.

[0062] In one example, the heat transfer delay time of the heat-absorbing pad may be, for example, 5 seconds or more. The heat transfer delay time may be 10 seconds or more, 20 seconds or more, 30 seconds or more, 40 seconds or more, 60 seconds or more, 80 seconds or more, 100 seconds or more, 120 seconds or more, 140 seconds or more, 160 seconds or more, 180 seconds or more, or 200 seconds or more. The longer the heat transfer delay time, the more advantageous it is, and although there is no specific upper limit, it may be, for example, 60 minutes or less.

[0063] The heat-absorbing pad may have irreversibility, meaning its shape does not return to its original state after heating and cooling. In one example, the X-ray diffraction (XRD) pattern of the heat-absorbing pad measured after heating it to 200°C and cooling it to room temperature may differ from the X-ray diffraction (XRD) pattern of the heat-absorbing pad before heating. Heating the heat-absorbing pad to 200°C may be maintained for about 60 minutes. The heat-absorbing pad before heating refers to the heat-absorbing pad at room temperature without heating. The room temperature may be, for example, in the range of 20°C to 30°C or about 25°C. If the heat-absorbing pad does not have the irreversibility, the XRD patterns before and after heating may be identical. Specifically, when XRD analysis is performed on an endothermic pad, a graph can be obtained where the x-axis is 2θ (2Theta) and the y-axis is intensity (au) (θ is the angle of incidence of the diffracted X-ray, and intensity is the intensity of the diffracted X-ray). Multiple diffraction peaks appear on the graph, and a pattern can be obtained from them. Different XRD patterns may mean that at least one of the multiple diffraction peaks does not appear. Identical XRD patterns may mean that the multiple diffraction peaks appear identically.

[0064] In one example, the thickness of the heat-absorbing pad may be, for example, 0.5 mm or more. Specifically, the thickness of the heat-absorbing pad may be 1 mm or more, 1.5 mm or more, 2 mm or more, 2.5 mm or more, or 3 mm or more. If the thickness of the heat-absorbing pad is within the above range, it may be advantageous to improve heat absorption performance and exhibit excellent heat transfer delay characteristics. The upper limit of the thickness of the heat-absorbing pad may be appropriately adjusted considering the battery module to which the pad is to be applied, for example, 10 mm or less, 9 mm or less, 8 mm or less, 7 mm or less, 6 mm or less, 5 mm or less, 4 mm or less, or 3 mm or less. In one example, the thickness of the pad may be less than 4 mm, 3.5 mm or less, 3.0 mm or less, 2.5 mm or less, or 2.0 mm or less. If the thickness of the pad is within the above range, it may be more advantageous in that it can exhibit a secondary temperature delay section.

[0065] Furthermore, the present application relates to a method for manufacturing a heat-absorbing pad. The manufacturing method may include a step of curing a resin composition for manufacturing a heat-absorbing pad. The above-described details may be equally applicable to the resin composition and the heat-absorbing pad.

[0066] The above manufacturing method may specifically include the step of applying a resin composition for manufacturing an endothermic pad onto a first substrate; the step of covering a second substrate onto the resin composition; and the step of curing the resin composition.

[0067] For the first substrate and the second substrate, a release film, a polymer film, or a glass plate may be used independently. In one example, a dam may be formed on the first substrate to accommodate the resin composition to be applied. The dam may have a predetermined height, and the internal space may be empty. The material of the dam may be, for example, silicone. The resin composition may be applied to the internal space of the dam. If the resin composition is a one-component resin composition (a single mixture is prepared by mixing silicone resin and a catalyst), the resin composition may be applied directly into the dam. If the resin composition is a two-component resin composition (a main component mixture and a curing agent mixture are prepared separately), the main component mixture and the curing agent mixture may be mixed and applied into the dam.

[0068] Pores may be formed in the heat-absorbing pad during the curing step. The curing step may proceed by maintaining the resin composition at a high temperature. The high temperature may be, for example, in the range of about 40°C to 200°C, specifically, 40°C or higher, 50°C or higher, 60°C or higher, 70°C or higher, or 80°C or higher, and may be 200°C or lower, 190°C or lower, 180°C or lower, 170°C or lower, 160°C or lower, or 150°C or lower. The holding time may be, for example, in the range of 5 minutes to 60 minutes or 5 minutes to 30 minutes.

[0069] The present application relates to the use of the resin composition and / or the heat-absorbing pad. In one example, the present application relates to a battery module comprising the resin composition and / or the heat-absorbing pad. Additionally, the present application relates to a battery pack cover comprising the resin composition and / or the heat-absorbing pad. The battery module or battery pack cover may comprise the resin composition in a cured state (i.e., a cured product of the resin composition).

[0070] The battery module described above may include a module case and battery cells. The battery cells may be housed within the module case. One or more battery cells may exist within the module case, and multiple battery cells may be housed within the module case. The number of battery cells housed within the module case is not specifically limited and is adjusted according to the intended use, etc. The battery cells housed within the module case may be electrically connected to one another. The type of battery cell housed within the module case is also not specifically limited, and various known battery cells may all be applied. In one example, the battery cell may be of the pouch type. A pouch-type battery cell may typically include an electrode assembly, an electrolyte, and a pouch outer casing.

[0071] A module case may include at least a side wall and a bottom plate forming an internal space in which a battery cell can be housed. Additionally, the module case may further include a top plate that seals the internal space. The side wall, bottom plate, and top plate may be formed integrally with each other, or the module case may be formed by assembling separate side walls, bottom plates, and / or top plates. The shape and size of such a module case are not particularly limited and may be appropriately selected depending on the application or the shape and number of battery cells housed in the internal space. In the above, the terms "top plate" and "bottom plate" are relative terms used to distinguish between the plates constituting the module case, as there are at least two plates. That is, it does not mean that in actual use, the top plate must necessarily be located at the top and the bottom plate must necessarily be located at the bottom.

[0072] The resin composition and / or heat-absorbing pad may be present on one side of a battery cell. If the battery module comprises a plurality of battery cells, the resin composition and / or heat-absorbing pad may be disposed between the battery cells. The resin composition and / or heat-absorbing pad maintain their original form without a change of state at the operating temperature of the battery, but when thermal runaway occurs, they can provide a cooling effect to the ignited cell through a change of state and delay the transfer of heat to adjacent cells.

[0073] The present application relates to a heat-absorbing pad. The heat-absorbing pad of the present application has a porous structure and can exhibit excellent heat-absorbing performance and excellent heat transfer delay characteristics. The heat-absorbing pad can be usefully used to delay heat transfer to adjacent battery cells during thermal runaway of a battery cell.

[0074] The present application will be specifically described through the following examples, but the scope of the present application is not limited by the following examples.

[0075] Example 1

[0076] 89 parts by weight of silicon vinyl resin (Andisil VS1000, AB Specialty Silicones) with a molecular weight of 18,000 g / mol and 11 parts by weight of random pendant type silicon-hydride resin (Andisil XL1342, AB Specialty Silicones) were added to the container of a paste mixer (Daehwa Tech, PDM-1K equipment) to make 100 parts by weight of binder resin. With respect to 100 parts by weight of binder resin, 180 parts by weight of KAl(SO4)2·12H2O particles (Daejeong Hwakum), 3 parts by weight of a dispersant (LP X 21879, BYK), and 30 parts by weight of NaHCO3 particles (Sigma-Aldrich) were added as endothermic particles, and the mixture was stirred for 2 minutes at 600 rpm and 500 rpm. After confirming that a uniform mixture had been achieved, the particles were degassed in the first step and mixed for 2 minutes at 600 rpm and 200 rpm. Subsequently, 0.3 parts by weight of a platinum-based catalyst (SRX-212, Dow Chemical) were added, and a second degassing was performed, mixing the mixture for 2 minutes at 600 rpm and 200 rpm to prepare a resin composition.

[0077] A frame-shaped silicone dam (the overall size of the dam is width × height = 12 cm × 12 cm, the internal size of the dam is width × height = 10 cm × 10 cm, and the height of the dam is 1 mm) was prepared on a fluorine release coating sheet. After applying the resin composition inside the silicone dam, it was covered with a fluorine release coating sheet. After pressing the fluorine release coating sheet with a glass plate, it was cured at a high temperature (120°C) for 10 minutes to produce a pad of uniform thickness (2 mm).

[0078] Example 2

[0079] A resin composition and a pad were prepared in the same manner as in Example 1, except that the endothermic particles were changed to 120 parts by weight of (Mg(H2PO4)2)·8H2O particles (Daejeong Hwakum Co.).

[0080] Example 3

[0081] A resin composition and a pad were prepared in the same manner as in Example 1, except that the endothermic particles were changed to 180 parts by weight of H3BO3 particles (Daejeong Hwakum Co., Ltd.).

[0082] Example 4

[0083] A resin composition and a pad were prepared in the same manner as in Example 1, except that the endothermic particles were changed to 40 parts by weight of (Mg(H2PO4)2)·8H2O particles (Daejeong Chemical Co.) and 100 parts by weight of H3BO3 particles (Daejeong Chemical Co.), and the foamed particles were changed to 10 parts by weight of Na2CO3 particles (Sigma-Aldrich).

[0084] Example 5

[0085] A resin composition and a pad were prepared in the same manner as in Example 1, except that the endothermic particles were changed to 180 parts by weight of H3BO3 particles (Daejeong Hwakum Co., Ltd.) and the foamed particles were changed to 10 parts by weight of Na2CO3 particles (Sigma-Aldrich Co., Ltd.).

[0086] Example 6

[0087] 10 parts by weight of silicone vinyl resin (Andisil VS1000, AB Specialty), 20 parts by weight of silicone vinyl resin (Andisil VS20000, AB Specialty), 10 parts by weight of silicone hydroxy resin (Andisil OH70, AB Specialty), 50 parts by weight of silicone hydroxy resin (Andisil OH2000, AB Specialty), and 10 parts by weight of silicone hydride resin (RH-202, Runhe) were added to the container of a paste mixer (Daehwa Tech, PDM-1K equipment), and the mixture was made to 100 parts by weight of binder resin. For every 100 parts by weight of binder resin, 70 parts by weight of magnesium phosphate hydrate (MPT-8, Chempia), 60 parts by weight of aluminum hydroxide (H-FW-90, Chalco), and 20 parts by weight of magnesium hydroxide (PM10, Gansu Kaimeite Materials Science) were added, along with 0.1 parts by weight of a curing retardant (Andisil MVC, AB specialty) and 0.1 parts by weight of a catalyst (SRX-212, Dow). Subsequently, the mixture was mixed for 3 minutes at 600 rpm and 500 rpm, and then degassed for 1 minute at 600 rpm and 100 rpm to prepare a compound (resin composition).

[0088] A frame-shaped silicone dam (the overall size of the dam is width × height = 12 cm × 12 cm, the internal size of the dam is width × height = 10 cm × 10 cm, and the height of the dam is 1 mm) was prepared on a fluorine release coating sheet. After applying the resin composition inside the silicone dam, it was covered with a fluorine release coating sheet. After pressing the fluorine release coating sheet with a glass plate, it was cured at a high temperature (120°C) for 10 minutes to produce a pad with a uniform thickness (2 mm).

[0089] Example 7

[0090] For the main component mixture, 25 parts by weight of silicone hydroxy resin (Andisil OH-70, AB Specialty) and 75 parts by weight of silicone hydroxy resin (Andisil OH-2000, AB Specialty) were added to the container of a paste mixer (Daehwa Tech, PDM-1K equipment) to make 100 parts by weight of binder resin. For every 100 parts by weight of binder resin, 100 parts by weight of aluminum hydroxide (H-FW-20, Chalco) was added, along with 0.2 parts by weight of a curing retardant (Andisil MVC, AB Specialty) and 0.1 parts by weight of a catalyst (SRX-212, Dow). For the curing agent component, 20 parts by weight of silicone vinyl resin (Andisil VS1000, AB Specialty), 50 parts by weight of silicone hydride resin (Andisil CE-500, AB Specialty), and 35 parts by weight of silicone hydride resin (XL-1342, AB Specialty) were added to the container of a paste mixer (Daehwa Tech, PDM-1K equipment) to make 100 parts by weight of binder resin. For every 100 parts by weight of binder resin, 90 parts by weight of boric acid (Daejeong Hwakum Co., Ltd.) were added. Subsequently, the mixture was mixed for 3 minutes at 600 rpm rotation and 500 rpm rotation, and then degassed and mixed for 1 minute at 600 rpm rotation and 100 rpm rotation to prepare the mixture.

[0091] A frame-shaped silicone dam (the overall size of the dam is width × height = 12 cm × 12 cm, the internal size of the dam is width × height = 10 cm × 10 cm, and the height of the dam is 1 mm) was prepared on a fluorine release coating sheet. The main component and the curing agent of the resin composition were mixed and applied inside the silicone dam, and then covered with a fluorine release coating sheet. After pressing the fluorine release coating sheet with a glass plate, it was cured at a high temperature (120°C) for 10 minutes to produce a pad of uniform thickness (2 mm).

[0092] Comparative Example 1

[0093] 68 parts by weight of silicone vinyl resin (VP10000, Dami Polychem Co.) and 32 parts by weight of silicone hydride resin (Andisil XL12, AB Specialty Silicones Co.) were placed in a container of a paste mixer (Daehwa Tech Co., PDM-1K equipment) and 100 parts by weight of binder resin were added. A mixture was prepared by adding 125 parts by weight of boric acid particles (Daejeong Chemical Co., Ltd.), 40 parts by weight of APP (Ammonium Phosphate) (FR-624E, Chempia Co., Ltd.) as flame retardant particles, 20 parts by weight of aluminum hydroxide particles (HWF-20, Chalco Co., Ltd.), 0.9 parts by weight of dispersant (LP X 21879, BYK Co., Ltd.), 0.8 parts by weight of curing retardant (VMC, HRS Co., Ltd.), 26 parts by weight of ethyl acetate solvent (Daejeong Chemical Co., Ltd.), and 0.4 parts by weight of catalyst (SRX-212, Dow Co., Ltd.) to 100 parts by weight of binder resin, and then mixing for 1 minute at 600 rpm of rotation and 500 rpm of rotation. A fluorine release film was placed on an automatic coating device, the coating gap was adjusted, and the mixture was poured onto the fluorine release film and coated. Next, the pad was prepared by drying in a Matisse oven at 130°C for 10 minutes. The thickness of the prepared heat-absorbing pad was approximately 2.0 mm.

[0094] Comparative Example 2

[0095] 68 parts by weight of silicone vinyl resin (VP10000, Dami Polychem Co.) and 32 parts by weight of silicone hydride resin (Andisil XL12, AB Specialty Silicones Co.) were placed in a container of a paste mixer (Daehwa Tech Co., PDM-1K equipment) and 100 parts by weight of binder resin were added. A mixture was prepared by adding 125 parts by weight of boric acid particles (Daejeong Chemical Co., Ltd.), 40 parts by weight of APP (Ammonium Phosphate) (FR-624E, Chempia Co., Ltd.) as flame retardant particles, 20 parts by weight of aluminum hydroxide particles (HWF-20, Chalco Co., Ltd.), 0.9 parts by weight of dispersant (LP X 21879, BYK Co., Ltd.), 0.8 parts by weight of curing retardant (VMC, HRS Co., Ltd.), 26 parts by weight of n-hexane solvent (Daejeong Chemical Co., Ltd.), and 0.4 parts by weight of catalyst (SRX-212, Dow Co., Ltd.) to 100 parts by weight of binder resin, and then mixing for 1 minute at 600 rpm of rotation and 500 rpm of rotation. A fluorine release film was placed on an automatic coating device, the coating gap was adjusted, and the mixture was poured onto the fluorine release film and coated. Next, the pad was manufactured by drying in a Matisse oven at 130°C for 10 minutes. The thickness of the manufactured heat-absorbing pad was approximately 1 mm.

[0096] Comparative Example 3

[0097] 50 parts by weight of caprolactone-based polyol (Capa2043, Perstorp) and 50 parts by weight of HDI trimer-based isocyanate (LV2, Covestro) were added to the container of a paste mixer (Daehwa Tech, PDM-1K equipment), and the mixture was made to 100 parts by weight of binder resin. For every 100 parts by weight of binder resin, 180 parts by weight of KAl(SO4)2·12H2O (Daejeong Hwakum Co.) and 10 parts by weight of water as a foaming agent were added, and the mixture was stirred for 2 minutes at 600 rpm and 500 rpm. After confirming that a uniform mixture had been achieved, the particles were degassed in the first step and mixed for 2 minutes at 600 rpm and 200 rpm. Then, 0.3 parts by weight of a tin-based catalyst (DBTDL, Sigma Aldrich) were added, and a second degassing process was carried out. The mixture was mixed for 2 minutes at 600 rpm and 200 rpm to prepare a resin composition.

[0098] A frame-shaped silicone dam (the overall size of the dam is width × height = 12 cm × 12 cm, the size of the inside of the dam is width × height = 10 cm × 10 cm, and the height of the dam is 1 mm) was prepared on a fluorine release coating sheet. After applying the resin composition inside the silicone dam, it was covered with a fluorine release coating sheet. After pressing the fluorine release coating sheet with a glass plate, it was cured at room temperature (25°C) for 3 hours to produce a pad with a uniform thickness (2 mm).

[0099] Comparative Example 4

[0100] A resin composition and a pad were prepared in the same manner as in Comparative Example 3, except that the endothermic particles were changed to 120 parts by weight of (Mg(H2PO4)2)·8H2O particles (Daejeong Hwakum Co.).

[0101] Comparative Example 5

[0102] A resin composition and a pad were prepared in the same manner as in Comparative Example 3, except that the endothermic particles were changed to 180 parts by weight of H3BO3 particles (Daejeong Hwakum Co., Ltd.).

[0103] Comparative Example 6

[0104] We used silicone foam products mass-produced by LG Chem.

[0105] Comparative Example 7

[0106] We used urethane foam products mass-produced by LG Chem.

[0107] Comparative Example 8

[0108] A resin composition and a pad were prepared in the same manner as in Example 1, except that the endothermic particles were changed to 180 parts by weight of Al(OH)3 particles (H-WF-75, Chalco).

[0109] Comparative Example 9

[0110] A resin composition and a pad were prepared in the same manner as in Example 1, except that the endothermic particles were changed to 180 parts by weight of Mg(OH)2 particles (Zerogen 100SP, Huber materials).

[0111] Comparative Example 10

[0112] A resin composition and a pad were prepared in the same manner as in Example 1, except that the endothermic particles were changed to 180 parts by weight of Al2O3 particles (BAK-70, Shanghai Bestry Performance Materials).

[0113] Comparative Example 11

[0114] A resin composition and a pad were prepared in the same manner as in Example 1, except that the endothermic particles were changed to 180 parts by weight of MgO particles (Sigma Aldrich).

[0115] Comparative Example 12

[0116] A resin composition and a pad were prepared in the same manner as in Example 1, except that an epoxy resin (YD-128, Kukdo Chemical Co.) was used instead of a silicone vinyl resin (Andisil VS1000, AB Specialty Silicones Co.), an amine compound (G-A0432, Kukdo Chemical Co.) was used instead of a silicone hydride resin (Andisil XL12, AB Specialty Silicones Co.), and a tertiary amine catalyst (KH-3001) was used instead of a Pt catalyst as a catalyst.

[0117] Evaluation Example 1. Density Measurement

[0118] The pads of the examples and comparative examples were cut into sizes of 3cm x 3cm to prepare samples, and their thickness (cm) and weight (g) were measured. Density (g / cm³) 3 ) was calculated from weight (g) / width (cm) × length (cm) × thickness (cm).

[0119] Evaluation Example 2. Pad shape evaluation

[0120] It was observed whether the pads of the examples and comparative examples had the form of foam pads. As a result of the evaluation, Examples 1 to 7 and Comparative Examples 1 to 2 and 6 to 11 had the form of foam pads, but Comparative Examples 3 to 5 were not manufactured in the form of foam pads. In the case of Comparative Examples 3 to 5, the NCO portion of the isocyanate reacted with the endothermic particles to produce water, and CO2 was generated from the reaction between the water and the NCO, resulting in non-uniform foaming. In the case of Comparative Example 12, the amine portion reacted with the endothermic particles to produce water, so a uniform mixture could not be obtained.

[0121] Evaluation Example 3. Evaluation of number of floors

[0122] The pads of the examples and comparative examples were cut to a width × length of 6 cm × 6 cm to prepare samples. Microscopic images (Dino-Lite DIGITAL MICROSCOPE Premier, AnMo, 50x magnification) were obtained for the side of the sample (the side parallel to the thickness direction), and the number of pores present in the thickness direction was defined as the number of pore layers. One pore layer is defined as a part where silicon and particles are absent, that is, a part that is empty due to the formation of holes. In the evaluation results of Tables 1 and 2, the number of pore layers is listed as a range such as "n1 - n2" to indicate that when observing the number of pore layers in the sample, a region with fewer pores is observed to have at least n1 layers, and a region with fewer pores is observed to have at least n2 layers.

[0123] Evaluation Example 4. Evaluation of thermal transition delay characteristics

[0124] The pads of the examples and comparative examples were cut to a width × height of 6 cm × 6 cm and prepared as samples. SUS frames were attached to the front and back surfaces of the samples. The SUS frames serve to prevent the samples from bending due to flames. The pads with the attached SUS frames were fixed vertically to a jig using clamps (the main surface of the pad is perpendicular to the ground, and the thickness direction of the pad is parallel to the ground). A butane gas torch (butane gas: Sun Lighter Gas 295 ml, Taeyang Industrial Co., Ltd., gas torch: 500 JET, Honest Co., Ltd.) was placed on the first main surface side of the pad, and a thermal imaging camera (A655SC, FLIR Co., Ltd.) was placed on the second surface side of the pad, opposite to the first main surface. The pixel resolution of the thermal imaging camera is 640 × 480, and the upper limit of the measurement temperature is 660°C. The gas torch was positioned so that the flame-emitting part of the gas torch was centered on the first main surface of the pad, and the thermal imaging camera lens was positioned so that the lens of the thermal imaging camera was centered on the second main surface of the pad. Additionally, the distance between the first main surface of the pad and the flame-emitting part of the gas torch was approximately 3 cm, and the distance between the second main surface of the pad and the thermal imaging camera lens was 40 cm. The ambient temperature before the flame was emitted from the gas torch was approximately 25°C. While heating the pad by emitting a flame from the torch, the temperature of the second main surface of the pad over time was measured using the thermal imaging camera. The thermal imaging camera measures the infrared radiation emitted by the pad and calculates the temperature based on the measured infrared radiation values. The duration of flame emission by the gas torch was set to 3 minutes. The temperature measured by the thermal imaging camera is the temperature of the highest temperature point in the heated part of the pad.

[0125] As described above, when a flame is applied to the pad, if the pad absorbs heat and maintains its temperature for a certain period without rising, it was evaluated as having a heat transfer delay effect. Specifically, in the graph of the pad's temperature (°C) against the measured time (seconds) when a flame is applied to the pad, a continuous section where the temperature change is 5°C or less can be defined as the heat transfer delay section. The temperature change being 5°C or less means that the temperature rise per second is 5°C or less. The temperature at the end point of the heat transfer delay section was set as the heat transfer delay temperature, and the time during which the heat transfer delay section is maintained was set as the heat transfer delay time. It was verified whether a heat transfer delay section appeared at a temperature below 200°C, and the heat transfer delay time was measured and recorded in Tables 1 to 3.

[0126] Evaluation Example 5. Residual Solvent Analysis

[0127] The amount of residual solvent in the sample was analyzed through quantitative analysis, which compares the peak height of a specific solvent measured for a standard of known concentration with the peak height of the specific solvent measured for the sample. Quantitative analysis assumes that the peak height of a solvent is proportional to its concentration; for example, if the peak height of solvent A is measured as 100 for a standard of 1 mg of solvent A and the peak height of solvent A is measured as 50 for a 1 g sample, the calculation method assumes that 0.5 mg of solvent A is present in the 1 g sample. The peak height of the solvent was measured using a Pyrolyzer and an EGA-GC / MS EIC Chromatogram. The specific analysis method is as follows.

[0128] As a result of the evaluation, no organic solvent components were detected in Examples 1 to 7 and Comparative Examples 3 to 12. On the other hand, Comparative Examples 1 and 2 were detected at 4.5 ug / g and 3.7 ug / g, respectively.

[0129] 1) Sample preparation

[0130] In the examples and comparative examples, the prepared pad was cut and about 2.0 mg was placed in a sample cup to prepare the sample.

[0131] 2) Preparation and measurement of standard forms

[0132] - A 10 ppm standard was prepared by diluting ethyl acetate in toluene.

[0133] - A 5 ppm standard was prepared by diluting n-hexane in toluene.

[0134] - Each standard form manufactured was measured three times using a direct injection method into a pyrolizer.

[0135] - Quantitative analysis was performed by comparing the average value of the peak heights of the solvent measured three times with the peak height of the solvent measured in the sample.

[0136] 3) Measurement conditions

[0137] (1) Pyrolyzer conditions

[0138] - Initial Value & Time: 100℃

[0139] - Program Rate : 10 ℃ / min

[0140] - Final Value & Time: 150℃

[0141] - Measurement equipment: Py-GC / MS-01

[0142] (2) GC-MS conditions

[0143] - Injector : 320 ℃

[0144] - Initial Value & Time: 50℃, 5min

[0145] - Program Rate : 10 ℃ / min

[0146] - Final Value & Time: 250℃

[0147] - Flow rate: 1 mL / min

[0148] - Split ratio: 1 / 50

[0149] - Scan : m / z 20-800

[0150] - Threshold : 150

[0151] (3) Standard measurement conditions

[0152] - Pyrolizer: 200 ℃, 5 min

[0153] - Injector : 320 ℃

[0154] - Initial Value & Time: 50℃, 5min

[0155] - Program Rate : 10 ℃ / min

[0156] - Final Value & Time: 250℃

[0157] - Flow rate: 1 mL / min

[0158] - Split ratio: 1 / 50

[0159] - Scan : m / z 20-800

[0160] - Threshold : 150

[0161] [Table 1]

[0162]

[0163] [Table 2]

[0164]

[0165] [Table 3]

[0166]

Claims

1. Contains an endothermic material and a binder resin, has a detection amount of organic solvent components of 3 µg / g or less upon GC-MS (Gas Chromatography-Mass Spectrometry) analysis, has a porous structure, and has a density of 0.2 g / cm³ 3 Up to 1 g / cm 3 An absorbent pad that is within the range and has a heat transfer delay time of 5 seconds or more at a temperature of less than 200°C when exposed to flame.

2. In claim 1, the endothermic material is an endothermic pad comprising solid acid particles.

3. In claim 1, the heat-absorbing material is a heat-absorbing pad comprising hydrate particles.

4. An endothermic pad according to claim 1, wherein the thermal decomposition temperature of the endothermic material is within the range of 50℃ to 300℃.

5. In claim 1, the pores of the porous structure exist in an internally empty state, forming an endothermic pad.

6. In claim 1, the binder resin is a heat-absorbing pad comprising silicone resin.

7. The heat-absorbing pad according to claim 1, wherein the binder resin comprises silicon vinyl resin, silicon hydroxy resin, or a mixture of silicon vinyl resin and silicon hydroxy resin.

8. The heat-absorbing pad according to claim 7, wherein the binder resin further comprises silicone hydride resin.

9. The heat-absorbing pad according to claim 1, comprising a heat-absorbing material in a range of 50 to 500 parts by weight per 100 parts by weight of binder resin.

10. The heat-absorbing pad according to claim 1, wherein the thickness of the heat-absorbing pad is within the range of 1㎛ to 5㎛.

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