Polyurethane foam composition and polyurethane foam containing the cured product

Abstract

The present invention relates to a polyurethane foam composition and a polyurethane foam containing the cured product thereof.

Description

[Technical field]

[0001] This application claims the benefit of the filing date of Korean Patent Application No. 10-2020-0115233, filed with the Korean Intellectual Property Office on September 9, 2020, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a polyurethane foam comprising a polyurethane foam composition and a cured product thereof. [Background technology]

[0003] Polyurethane foam is widely used in a wide range of daily necessities, including automobile parts, because it is relatively inexpensive, easy to mold, and has high elasticity. However, when polyurethane foam is used in electronic products, etc., there is a problem that if the flammable polyurethane foam ignites due to a short circuit or the like, it will burn uncontrollably, causing minor damage to the product and major fires and explosions.

[0004] To solve these problems, a method of imparting flame retardancy by laminating a flame-retardant sheet or panel on one side of polyurethane foam has been mainly used, but this method does not fundamentally impart flame retardancy to polyurethane foam, so the flame retardant effect is limited and the manufacturing process is complicated, which increases manufacturing costs. Also, in order to impart flame retardancy to polyurethane foam itself, flame retardants composed of halogen compounds such as bromine compounds and chlorine compounds are added, but this can cause problems for the human body and the environment due to toxic gases when burned.

[0005] Meanwhile, polyurethane foam is used as a buffer material for buffering volumetric changes caused by charging and discharging of battery cells. Generally, battery cells are used in a manner that the volume increases when the battery cells are charged. In this case, polyurethane foam is used as a sealing agent between battery cells when manufacturing the battery cells in order to prevent problems such as explosion by mitigating the volumetric expansion of the battery.

[0006] In the automated process of assembling a battery pack, the polyurethane foam must be attached to a vacuum suction plate in the automated process. However, if the suction pressure is too low, the polyurethane foam cannot be attached to the vacuum suction plate to the required level, which causes a problem that the product cannot be transferred, and therefore the automated process is not applicable. If the suction pressure is too low, the suction plate and the polyurethane foam may separate during the tape lamination process.

[0007] In order to increase the adsorption pressure, attempts have been made to increase the density of the polyurethane foam to increase the adsorption power, but this has also resulted in problems in terms of cost and post-adsorption processes.

[0008] In order to solve the above problems, there is currently a need to develop a foam that is flame-retardant, has low density, and yet has excellent adsorption power. Summary of the Invention [Problem to be solved by the invention]

[0009] The present disclosure seeks to provide polyurethane foams comprising the polyurethane foam composition and the cured product thereof.

[0010] However, the problems to be solved by the present invention are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description. [Means for solving the problem]

[0011] One embodiment of the present invention provides a polyurethane foam composition comprising a polyol mixture including a first polyol-based compound having a glass transition temperature of -50°C or lower; a second polyol-based compound having at least three functional groups reactive with an isocyanate group and a weight average molecular weight of 5,000 g / mol or more and 30,000 g / mol or less; and a third polyol-based compound having a heat release capacity of 500 J / g K or less; an isocyanate-based curing agent; and a filler, wherein the filler is included in an amount of 10 parts by weight or more and 20 parts by weight or less per 100 parts by weight of the polyol mixture.

[0012] Another embodiment of the present invention provides a polyurethane foam comprising a cured product of the polyurethane foam composition. Effect of the Invention

[0013] The polyurethane foam composition according to one embodiment of the present invention can provide a polyurethane foam that is both low in density and excellent in adsorption power.

[0014] The polyurethane foam according to one embodiment of the present invention has excellent suction power, and therefore, during an automated process, the polyurethane foam can be easily moved by using a vacuum suction plate, resulting in excellent tape lamination workability.

[0015] When applied between battery cells, the polyurethane foam according to one embodiment of the present invention can achieve dimensional stability against volume changes of the cells, excellent stress absorption against vibration and impact, excellent resilience, and high fire resistance.

[0016] The effects of the present invention are not limited to those described above, and effects not mentioned will be clearly understood by those skilled in the art from the present specification and the accompanying drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] In this specification, when a part "comprises" a certain component, this means that it can further include other components, not excluding other components, unless specifically stated to the contrary.

[0018] Throughout this specification, the unit "parts by weight" can refer to the weight ratio between each component.

[0019] Throughout this specification, "A and / or B" means "A and B, or A or B."

[0020] Throughout this specification, the "weight average molecular weight" and "number average molecular weight" of a compound are calculated using the molecular weight and molecular weight distribution of the compound. Specifically, tetrahydrofuran (THF) and the compound are placed in a 1 mL glass bottle to prepare a sample specimen with a compound concentration of 1 wt%, and a standard sample (polystyrene) and the sample specimen are filtered through a filter (pore size 0.45 mm) and then injected into a GPC injector, and the elution time of the sample specimen is compared with the calibration curve of the standard specimen to obtain the molecular weight and molecular weight distribution of the compound. In this case, an Infinity II 1260 (Agilient) can be used as a measuring device, and the flow rate can be set to 1.00 mL / min and the column temperature to 40.0°C.

[0021] Throughout the present specification, the term "glass transition temperature (Tg)" may be measured using differential scanning analysis. Specifically, a DSC (Differential Scanning Calorimeter, DSC-STAR3, METTLER TOLEDO) is used to heat a sample in the temperature range of -60°C to 150°C at a heating rate of 5°C / min, and two cycles of experiments are performed in the range. The midpoint of the DSC curve created at a certain point of heat change is measured to determine the glass transition temperature.

[0022] Throughout this specification, the viscosity of the compounds may be as measured with a Brookfield viscometer at a temperature of 25°C.

[0023] The present specification will be explained in further detail below. One embodiment of the present invention provides a polyurethane foam composition comprising a polyol mixture including a first polyol-based compound having a glass transition temperature of -50°C or lower; a second polyol-based compound having at least three functional groups reactive with an isocyanate group and a weight average molecular weight of 5,000 g / mol or more and 30,000 g / mol or less; and a third polyol-based compound having a heat release capacity of 500 J / g K or less; an isocyanate-based curing agent; and a filler, wherein the filler is included in an amount of 10 parts by weight or more and 20 parts by weight or less per 100 parts by weight of the polyol mixture.

[0024] The polyurethane foam composition according to one embodiment of the present invention can provide a polyurethane foam having excellent adsorption properties.

[0025] Each of the components of the polyurethane foam composition according to one embodiment of the present invention will be described in detail below.

[0026] (1) First polyol compound According to one embodiment of the present invention, the first polyol-based compound may have a glass transition temperature of -50° C. or less. Specifically, the glass transition temperature of the first polyol-based compound may be -80° C. or more and -50° C. or less, or -75° C. or more and -60° C. or less. When the glass transition temperature of the first polyol-based compound is within the above-mentioned range, the polyurethane foam including the cured product of the polyurethane foam composition may have high resilience and compression recovery properties.

[0027] The first polyol compound may have a viscosity of 2,000 mPa·s or less at 25° C. Specifically, the viscosity of the first polyol compound may be 200 mPa·s or more and 2,000 mPa·s or less at 25° C. Adjusting the viscosity of the first polyol compound to within the above-mentioned range has the advantage of improving the dispersibility and workability of raw materials during the production of the polyurethane foam.

[0028] According to one embodiment of the present invention, the first polyol-based compound may be a polyether-based polyol having a glass transition temperature of −50° C. or lower, having a polyalkylene oxide unit, and having a viscosity of 2,000 mPa s or lower at 25° C.

[0029] In addition, the first polyol-based compound may include at least two functional groups that react with an isocyanate group. The functional group that reacts with an isocyanate group may mean a functional group that forms a urethane bond with an isocyanate group. Specifically, the functional group that reacts with an isocyanate group may be a hydroxy group, an amine group, a thiol group, or a carboxy group. More specifically, the first polyol-based compound has hydroxy groups bonded to both ends of the main chain, and at least one of the hydroxy group, the amine group, the thiol group, and the carboxy group is included in the side chain of the first polyol-based compound.

[0030] According to one embodiment of the present invention, the first polyol-based compound may be a polymer of a first mixture including one or more of an ether-based polyol, an ester-based polyol, and a chain extender.

[0031] The ether-based polyol, ester-based polyol, and chain extender may be any of those used in the art. For example, the ether-based polyol may be polypropylene glycol, polytetramethylene glycol, or the like. The ester-based polyol may be polycaprolactone polyol, or the like. The chain extender may be butanediol, or the like.

[0032] According to one embodiment of the present invention, the content of the first polyol-based compound may be 60 parts by weight or more and 75 parts by weight or less, based on 100 parts by weight of the polyol mixture. Specifically, the content of the first polyol-based compound may be 62.5 parts by weight or more and 72.5 parts by weight or less, 65 parts by weight or more and 70 parts by weight or less, or 67 parts by weight or more and 73 parts by weight or less, based on 100 parts by weight of the polyol mixture. By adjusting the content of the first polyol-based compound within the above-mentioned range, the compression recovery property of a polyurethane foam including a cured product of the polyurethane foam composition can be improved.

[0033] In the present specification, the polyol mixture may refer to the entire polyol-based material including the first polyol-based compound, the second polyol-based compound, and the third polyol-based compound, and the polyol mixture may refer to the first polyol-based compound, the second polyol-based compound, and the third polyol-based compound.

[0034] (2) Second polyol compound According to one embodiment of the present invention, the second polyol-based compound may include at least three functional groups that react with an isocyanate group. The functional group that reacts with an isocyanate group may mean a functional group that forms a urethane bond with the isocyanate group. Specifically, the functional group that reacts with an isocyanate group may be a hydroxy group, an amine group, a thiol group, or a carboxy group.

[0035] According to one embodiment of the present invention, the second polyol-based compound may have a branched chain structure. Specifically, the second polyol-based compound may have hydroxyl groups bonded to both ends and one or more functional groups reactive with an isocyanate group bonded to the main chain to form a side chain. Specifically, the second polyol-based compound contains three or more functional groups reactive with an isocyanate group, and thus can form a denser network structure during urethane polymerization than a polyol having a linear structure in which hydroxyl groups are bonded only to both ends.

[0036] According to one embodiment of the present invention, the weight average molecular weight of the second polyol-based compound may be 5,000 g / mol to 30,000 g / mol. Specifically, the weight average molecular weight of the second polyol-based compound may be 7,000 g / mol to 28,000 g / mol, 10,000 g / mol to 25,000 g / mol, 12,000 g / mol to 20,000 g / mol, or 15,000 g / mol to 18,000 g / mol. The second polyol-based compound serves as a skeleton of the polyurethane foam, and when the weight average molecular weight of the second polyol-based compound is within the above range, the compression recovery ability of the polyurethane foam can be effectively improved.

[0037] According to one embodiment of the present invention, the second polyol-based compound may have a viscosity of 20,000 mPa·s or more and 200,000 mPa·s or less at 25° C. Specifically, the viscosity of the second polyol-based compound at 25° C. may be 30,000 mPa·s or more and 180,000 mPa·s or less, 35,000 mPa·s or more and 150,000 mPa·s or less, 50,000 mPa·s or more and 120,000 mPa·s or less, 60,000 mPa·s or more and 100,000 mPa·s or less, or 35,000 mPa·s or more and 70,000 mPa·s or less. When the viscosity of the second polyol-based compound is within the above-mentioned range, it is possible to uniformly disperse the second polyol-based compound with other substances in the polyurethane composition, and a polyurethane foam of uniform quality can be produced.

[0038] According to one embodiment of the present invention, the second polyol-based compound may be a polyether-based polyol containing at least three functional groups reactive with an isocyanate group, having a weight average molecular weight of 5,000 g / mol or more and 30,000 g / mol or less, and having a viscosity at 25°C of 20,000 mPa s or more and 200,000 mPa s or less.

[0039] According to one embodiment of the present invention, the second polyol-based compound may be a polymer of a second mixture including a polyether-based polyol; a polyfunctional isocyanate-based compound; and a chain extender having three or more functional groups reactive with an isocyanate group.

[0040] According to one embodiment of the present invention, the polyether-based polyol in the second mixture may be derived from a polyalkylene oxide. Specifically, the polyether-based polyol in the second mixture may include at least one of polyethylene glycol (PEG), polypropylene glycol (PPG), PEG-PPG copolymer (polyethylene glycol-polypropylene glycol copolymer), and poly(tetramethylene ether) glycol (PTMG).

[0041] According to one embodiment of the present invention, the molar ratio of the polyether polyol to the multifunctional isocyanate compound in the second mixture may be 1:0.5 or more and 1:1 or less. Specifically, the molar ratio of the polyether polyol to the multifunctional isocyanate compound in the second mixture may be 1:0.6 or more and 1:0.95 or less, or 1:0.65 or more and 1:0.9 or less.

[0042] When the content of the polyfunctional isocyanate-based compound in the second mixture is within the above range, the viscosity of the second polyol-based compound produced can be prevented from becoming excessively high, improving compatibility with other components and preventing gelation.

[0043] According to one embodiment of the present invention, the polyfunctional isocyanate compound in the second mixture may contain two isocyanate groups. The polyfunctional isocyanate compound in the second mixture may contain at least one of an aromatic polyfunctional isocyanate compound, an alicyclic polyfunctional isocyanate compound, and an aliphatic polyfunctional isocyanate compound.

[0044] Specifically, the aromatic polyfunctional isocyanate compound can include at least one of 2,4-tolylene diisocyanate (TDI), 2,6-tolylene diisocyanate (TDI), m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), 2,4'-diphenylmethane diisocyanate (MDI), 2,2'-diphenylmethane diisocyanate (MDI), xylylene diisocyanate (XDI), 3,3'-dimethyl-4,4'-biphenylene diisocyanate, and 3,3'-dimethoxy-4,4'-biphenylene diisocyanate.

[0045] The alicyclic polyfunctional isocyanate compound may include at least one of 4,4'-methylene dicyclohexyl diisocyanate (H12-MDI), cyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI), dicyclohexylmethane-4,4'-diisocyanate, and hydrated xylylene diisocyanate (H6-XDI), and methylcyclohexane diisocyanate.

[0046] The aliphatic polyfunctional isocyanate compound may include at least one of butane-1,4-diisocyanate, hexamethylene diisocyanate (HDI), isopropylene diisocyanate, methylene diisocyanate, and lysine isocyanate.

[0047] According to one embodiment of the present invention, the second mixture may have a molar ratio of the polyether-based polyol to the chain extender of 1:0.1 or more and 1:0.45 or less.

[0048] Specifically, the molar ratio of the polyether polyol to the chain extender may be 1:0.2 or more and 1:0.4 or less, or 1:0.25 or more and 1:0.35 or less, more specifically, 1:0.3.

[0049] When the content of the chain extender in the second mixture is within the above range, there is an advantage in that appropriate crosslinks are formed in the polyurethane foam, thereby realizing excellent compression recovery performance.

[0050] According to one embodiment of the present invention, the chain extender in the second mixture may be a compound containing three or more functional groups reactive with an isocyanate group, and the number of the functional groups contained in the chain extender may be 3 to 10 or 3 to 5.

[0051] According to one embodiment of the invention, the chain extender in the second mixture may comprise one or more of the following compounds: [ka]

[0052] According to one embodiment of the present invention, the content of the second polyol compound may be 5 parts by weight or more and 20 parts by weight or less with respect to 100 parts by weight of the polyol mixture. Specifically, the content of the second polyol compound may be 5 parts by weight or more and 15 parts by weight or less with respect to 100 parts by weight of the polyol mixture.

[0053] When the content of the second polyol-based compound is within the above-mentioned range, the polyurethane foam formed using the polyurethane foam composition can maintain its softness and achieve excellent resilience. In addition, by controlling the content of the second polyol-based compound within the above-mentioned range, the loss of compression recovery force can be minimized, thereby ensuring the durability of the polyurethane foam.

[0054] (3) Third polyol compound According to one embodiment of the present invention, the third polyol-based compound may be a polyol having a heat release capacity of 500 J / g·K or less; or a polymer of a third mixture including a polyol having a heat release capacity of 500 J / g·K or less and a polyfunctional isocyanate-based compound.

[0055] According to one embodiment of the present invention, the third polyol compound itself may have flame retardant properties, thereby improving the flame retardant performance of the polyurethane foam.

[0056] According to one embodiment of the present invention, the third polyol-based compound may include at least one of a polycarbonate diol having a heat release capacity of 500 J / g·K or less and a polydimethyl siloxane diol having a heat release capacity of 500 J / g·K or less.

[0057] According to one embodiment of the present invention, the polyol having a heat release capacity of 500 J / g·K or less may be a polyol having a limiting oxygen index value of 21% or more.

[0058] According to one embodiment of the present invention, the third polyol-based compound may be a polymer formed using a third mixture containing a polyol having a heat release capacity of 500 J / g·K or less and a polyfunctional isocyanate-based compound. That is, the polymer may have a heat release capacity of 500 J / g·K or less. The third polyol-based compound may be a polymer formed using a third mixture containing a polyol having a heat release capacity of 500 J / g·K or less and a limiting oxygen index of 21% or more and a polyfunctional isocyanate-based compound. That is, the polymer formed using the third mixture may have a heat release capacity of 500 J / g·K or less and a limiting oxygen index of 21% or more.

[0059] According to one embodiment of the present invention, the third polyol-based compound has a heat release capacity of 500 J / g·K or less, or has a heat release capacity of 500 J / g·K or less and a limit oxygen index value of 21% or more, so that the third polyol-based compound itself can possess flame retardant properties, thereby improving the flame retardant performance of the polyurethane foam.

[0060] According to one embodiment of the present invention, the polyfunctional isocyanate compound in the third mixture can improve the compatibility of the third polyol compound with other components. The polyfunctional isocyanate compound in the third mixture may be the same substance as the polyfunctional isocyanate compound in the second mixture.

[0061] According to one embodiment of the present invention, the third mixture may have a molar ratio of the polyol having a heat release capacity of 500 J / g·K or less to the multifunctional isocyanate compound of 1:0.05 to 1:0.25. Specifically, the molar ratio of the polyol having a heat release capacity of 500 J / g·K or less to the multifunctional isocyanate compound may be 1:0.05 to 1:0.15, or 1:0.07 to 0.12, more specifically, 1:0.1.

[0062] When the content of the polyfunctional isocyanate compound in the third mixture is within the above range, the polymer formed using the third mixture can have improved compatibility with other compositions.

[0063] According to one embodiment of the present invention, the content of the third polyol compound may be 15 parts by weight or more and 50 parts by weight or less, based on 100 parts by weight of the polyol mixture. Specifically, the content of the third polyol compound may be 25 parts by weight or more and 40 parts by weight or less, or 25 parts by weight or more and 35 parts by weight, based on 100 parts by weight of the polyol mixture.

[0064] By adjusting the content of the third polyol-based compound within the above range, compatibility with other materials in the polyurethane foam composition can be ensured. In addition, when the content of the third polyol-based compound is within the above range, the polyurethane foam can achieve flame retardancy of V-0 grade in the UL-94 vertical flame retardancy test, and hardening of the polyurethane foam can be minimized.

[0065] According to one embodiment of the present invention, the viscosity of the third polyol compound may be 1,000 mPa·s or more and 7,000 mPa·s or less, or 1,500 mPa·s or more and 5,000 mPa·s or less. When the viscosity of the third polyol compound is within the above range, there is an advantage in that compatibility with other components in the polyurethane foam composition can be ensured.

[0066] According to one embodiment of the present invention, the total content of the second polyol compound and the third polyol compound may be 30 parts by weight or more and 60 parts by weight or less, based on 100 parts by weight of the polyol mixture. Specifically, the total content of the second polyol compound and the third polyol compound may be 30 parts by weight or more and 50 parts by weight or less, or 30 parts by weight or more and 45 parts by weight or less, or 30 parts by weight or more and 40 parts by weight or less, based on 100 parts by weight of the polyol mixture.

[0067] By adjusting the total content of the second polyol-based compound and the third polyol-based compound within the above-mentioned range, the flame retardancy and compression properties of the polyurethane foam including the cured product of the polyurethane foam composition can be effectively improved.

[0068] (4) Filler A polyurethane foam composition according to an embodiment of the present invention includes a filler, which can improve the hardness and adsorption pressure of the polyurethane foam and maintain the CFD at an appropriate level.

[0069] According to one embodiment of the present invention, the filler may include one or more of silicon dioxide, silica, ATH, and calcium carbonate, and is particularly preferably, but not limited to, calcium carbonate.

[0070] According to one embodiment of the present invention, the filler is included in an amount of 10 to 20 parts by weight, specifically 12 to 18 parts by weight, based on 100 parts by weight of the polyol mixture. By including the filler in an amount within this range, the product can maintain an appropriate hardness while achieving high vacuum suction pressure, excellent workability in automated processes, reduced compression set, a smooth surface, and excellent appearance, while achieving an appropriate level of CFD.

[0071] CFD (Compression Force Deformation) is a parameter that indicates the repulsive force when the measurement object is compressed. Specifically, CFD can be used to measure the repulsive force when polyurethane foam is cut into 5cm x 5cm pieces and compressed using a device such as a UTM, and this can be evaluated with CFD, with the repulsive force being approximately 0.05 to 0.18 kg / cm. 2 If CFD has an appropriate level of value, when polyurethane foam is applied to a battery cell, it can improve product stability by buffering the volume change caused by the battery expansion and maintaining a constant volume.

[0072] (5) Foam stabilizer and foam-forming gas source The polyurethane foam composition according to one embodiment of the present invention may contain a foam stabilizer. The foam stabilizer is added to produce a foam shape, and can be applied as long as it is one generally used in the production of polyurethane foam. Specifically, the foam stabilizer may contain at least one of a silicone-based foam stabilizer, an organosilicon-based foam stabilizer, a fluorine-based foam stabilizer, an ionic surfactant, and a nonionic surfactant. More specifically, the foam stabilizer may contain polydimethylsiloxane substituted with polyalkyl oxide. However, the foam stabilizer is not limited thereto, and foam stabilizers generally used in the industry may be used. By using the foam stabilizer, the foaming gas forms a foam structure suitable for polyurethane foam, and when cured into the polyurethane foam, the gas maintains stable dispersibility to form pores of uniform size and distribution.

[0073] According to one embodiment of the present invention, the content of the foam stabilizer may be 0.5 parts by weight or more and 10 parts by weight or less, 1 part by weight or more and 5 parts by weight or less, or 2 parts by weight or more and 4 parts by weight or less, relative to 100 parts by weight of the polyol mixture.

[0074] The polyurethane foam composition according to one embodiment of the present invention may include a foam-forming gas source, which interacts with a foam stabilizer to foam and thereby form pores in the polyurethane foam.

[0075] The foam-forming gas is a gas that does not adversely affect the reaction between the polyol compound and the isocyanate, and may be an inert gas such as dry air and / or nitrogen gas, but is not limited to the above. The foam-forming gas composition may be a liquid gas, for example, liquid nitrogen.

[0076] The foam-forming gas source may be included in an amount that varies depending on the desired density of the polyurethane foam.

[0077] (6) Isocyanate-based hardener According to one embodiment of the present invention, the isocyanate-based curing agent may form a urethane bond with the first polyol-based compound to the third polyol-based compound to form a polyurethane network.

[0078] According to one embodiment of the present invention, the isocyanate curing agent is a compound containing two or more isocyanate groups, and can include at least one of an aromatic isocyanate compound, an alicyclic isocyanate compound, and an aliphatic isocyanate compound. The aromatic isocyanate compound, the alicyclic isocyanate compound, and the aliphatic isocyanate compound as the isocyanate curing agent can be the same as the aromatic isocyanate compound, the alicyclic isocyanate compound, and the aliphatic isocyanate compound in the second mixture described above.

[0079] According to one embodiment of the present invention, the content of the isocyanate-based curing agent may be 20 parts by weight or more and 35 parts by weight or less, based on 100 parts by weight of the polyol mixture. Specifically, the content of the isocyanate-based curing agent may be 25 parts by weight or more and 32.5 parts by weight or less, 27.5 parts by weight or more and 30 parts by weight or less, or 28 parts by weight or more and 32 parts by weight or less, based on 100 parts by weight of the polyol mixture. By adjusting the content of the isocyanate-based curing agent within the above-mentioned range, the urethane bond reaction with the first polyol compound to the third polyol compound contained in the polyol mixture is effectively carried out.

[0080] (7) Other additives According to one embodiment of the invention, the polyurethane foam composition may further comprise additives including one or more of a flame retardant, a catalyst, a crosslinking agent, and a dye.

[0081] According to one embodiment of the present invention, the flame retardant may include a non-halogen flame retardant. Specifically, the flame retardant may include a solid or liquid non-halogen phosphorus-based flame retardant. Specifically, according to one embodiment of the present invention, the flame retardant may include one or more selected from the group consisting of phosphate, phosphonate, phosphinate, phosphine oxide, and phosphazene. Specifically, the flame retardant may be aluminum phosphate. However, the flame retardant is not limited thereto, and phosphorus-based flame retardants commonly used in the industry may be used.

[0082] The non-halogen type phosphorus-based flame retardant reacts with flammable materials to form a carbonized film on the polymer surface, which blocks oxygen required for combustion and enhances the flame retardancy of the polyurethane foam. In addition, the non-halogen type phosphorus-based flame retardant reacts with oxygen elements in the polymer to perform dehydration and carbonization, and the radicals generated by the decomposition of phosphoric acid can play a role in stabilizing -OH and -H, which are active radicals generated by combustion.

[0083] According to one embodiment of the present invention, the flame retardant may include a mixture of the phosphorus-based flame retardant and a flame-retardant melamine powder. Specifically, the flame-retardant melamine powder may be MCA (melamine cyanurate).

[0084] According to one embodiment of the present invention, the content of the flame retardant may be 20 parts by weight or more and 50 parts by weight or less, based on 100 parts by weight of the polyol mixture. Specifically, the content of the flame retardant may be 20 parts by weight or more and 40 parts by weight or less, 21 parts by weight or more and 30 parts by weight or less, or 25 parts by weight or more and 30 parts by weight or less, based on 100 parts by weight of the polyol mixture.

[0085] When the content of the flame retardant is within the above range, it is possible to obtain the effect of decreasing the heat release capacity of the polyol-based compound in the polyurethane foam composition and increasing the limit oxygen index. In addition, when the content of the flame retardant is within the above range, it is possible to effectively remove radicals generated during combustion by forming the polymer of the polyurethane foam into char during combustion. Furthermore, when the content of the flame retardant is within the above range, it is possible to minimize the decrease in compression recovery performance of the polyurethane foam and ensure flame retardancy.

[0086] According to one embodiment of the present invention, in order to further improve the flame retardancy of the polyurethane foam, expandable graphite may be included.

[0087] According to an embodiment of the present invention, the size of the expanded graphite may be 150 μm to 300 μm. Specifically, the size of the expanded graphite may be 165 μm to 300 μm, 180 μm to 300 μm, or 200 μm to 300 μm. The expanded graphite has a layered crystal structure, and when heated, it expands to 20 to 400 times its original size, and can induce the formation of porous charcoal during combustion. By adjusting the size of the expanded graphite to the above range, the flame retardant property of the polyurethane foam can be effectively improved. Specifically, when the size of the expanded graphite is within the above range, the polyurethane foam can have a flame retardant property of V-0 grade as a result of a UL-94 vertical flame retardant test. More specifically, the polyurethane foam may satisfy the flame retardancy of V-0 grade in the UL-94 vertical flame retardancy test, and may have a total after-flame time of less than 2 seconds after the first flame application for five test pieces in the UL-94 vertical flame retardancy test. That is, the polyurethane foam has the advantage of having excellent flame retardancy even among V-0 grades in the UL-94 vertical flame retardancy test.

[0088] According to one embodiment of the present invention, the size of the expanded graphite may refer to the longest length from one end to the other end of the expanded graphite. Also, the expanded graphite may include a plurality of expanded graphite particles, and the size of the expanded graphite may be an average value of the sizes of the plurality of expanded graphite particles.

[0089] According to one embodiment of the present invention, the size of the expanded graphite can be measured by using any method known in the art for measuring particle size, without limitation. For example, the expanded graphite can be photographed using a scanning electron microscope (SEM), and the size of the expanded graphite can be measured using the photographed image.

[0090] According to one embodiment of the present invention, the content of the expanded graphite may be more than 0 parts by weight and not more than 50 parts by weight, based on 100 parts by weight of the polyol mixture. Specifically, the content of the expanded graphite may be 21 parts by weight or more and 40 parts by weight or less, or 21 parts by weight or more and 30 parts by weight or less, based on 100 parts by weight of the polyol mixture. When the content of the expanded graphite is adjusted within the above range, the flame retardancy of the polyurethane foam can be improved without decreasing the compression recovery force.

[0091] According to one embodiment of the present invention, the weight ratio of the flame retardant to the expandable graphite may be 1:0.8 or more and 1:1.2 or less. Specifically, the weight ratio of the flame retardant to the expandable graphite may be 1:0.9 or more and 1:1.1 or less, more specifically, 1:1.

[0092] When the content of the flame retardant and the expandable graphite is adjusted within the above ranges, the polyurethane foam formed using the polyurethane foam composition can have flame retardant properties of V-0 grade. Also, the polyurethane foam can have excellent flame retardant properties among the V-0 grade flame retardant properties.

[0093] According to one embodiment of the present invention, the catalyst may be an amine catalyst and / or a metal catalyst. Specifically, the amine catalyst may include at least one of a monoamine compound, a diamine compound, a triamine compound, a polyamine compound, a cyclic amine compound, an alcohol amine compound, and an ether amine compound. Also, the metal catalyst may include at least one of a nickel compound, an organotin compound, an organobismuth compound, an organolead compound, an organonickel compound, and an organozinc compound. Specifically, according to one embodiment of the present invention, the catalyst may be dibutyltin dilaurate.

[0094] According to one embodiment of the present invention, the content of the catalyst may be 0.5 parts by weight or more and 10 parts by weight or less, 1 part by weight or more and 10 parts by weight or less, or 1 part by weight or more and 5 parts by weight or less, relative to 100 parts by weight of the polyol mixture.

[0095] According to one embodiment of the present invention, the crosslinking agent may be a low molecular weight compound having 2 to 4 active hydrogen-containing groups capable of reacting with an isocyanate group and having a number average molecular weight of 50 to 800 g / mol. Specifically, the crosslinking agent may include at least one of ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, glycerin, trimethylolpropane, triethanolamine, and pentaerythritol.

[0096] According to one embodiment of the present invention, the content of the crosslinking agent may be 1 part by weight or more and 20 parts by weight or less, or 5 parts by weight or more and 15 parts by weight or less, based on 100 parts by weight of the polyol mixture.

[0097] According to one embodiment of the present invention, the dye can impart a color to a polyurethane foam containing a cured product of the polyurethane foam composition. As the dye, any dye used in the art can be used without limitation, and for example, carbon black can be used.

[0098] The content of the dye may be 1 part by weight or more and 3 parts by weight or less based on 100 parts by weight of the polyol mixture. By adjusting the content of the dye within the above range, it is possible to realize a color of the polyurethane foam without affecting the physical properties of the polyurethane foam.

[0099] One embodiment of the present invention provides a polyurethane foam comprising the cured polyurethane foam composition described above.

[0100] One embodiment of the present invention provides a polyurethane foam formed using the polyurethane foam composition. A method for producing a polyurethane foam using the polyurethane foam composition may utilize a commonly known method for producing a polyurethane foam.

[0101] According to an embodiment of the present invention, a polyurethane foam has an adsorption pressure of 50 kPa or more, 50 kPa to 95 kPa or 60 kPa to 95 kPa. When the polyurethane foam has an adsorption pressure within the above range, the polyurethane foam has excellent workability in an automated process and corresponds to an appropriate pressure in a process of assembling a battery pack.

[0102] According to one embodiment of the present invention, the polyurethane foam may have a flame retardant property of V-0 grade as a result of the UL-94 vertical flame retardant test. Therefore, the flame retardant polyurethane foam according to one embodiment of the present invention has an advantage of excellent flame retardant property.

[0103] For the UL-94 vertical flame retardancy test, a sample with a width of 125±25mm, a length of 13.0±0.5mm, and a thickness of 2.0mm is prepared. Five test pieces, each consisting of two samples, are prepared and stored at 23±2℃ and 50±5% humidity, and the flame retardancy is 37MJ / m 3 Each test piece is burned twice for 10 seconds using a blue flame of methane gas (flame height 20 mm, distance between the bottom of the test piece and the end of the burner 9.5 mm) with a calorific value of 10 ...

[0104] [Table 1]

[0105] According to an embodiment of the present invention, the polyurethane foam may have a total afterflame time of less than 2 seconds after a first flame exposure for five test specimens in a UL-94 vertical flame test. Specifically, the total afterflame time remaining on the five test specimens after burning for 10 seconds in the UL-94 vertical flame test may be less than 2 seconds. According to an embodiment of the present invention, the polyurethane foam may have a total afterflame time of less than 5 seconds after a second flame exposure for five test specimens in a UL-94 vertical flame test. Specifically, the total afterflame time remaining on the five test specimens after burning for 10 seconds twice in the UL-94 vertical flame test may be less than 5 seconds.

[0106] Therefore, the polyurethane foam according to one embodiment of the present invention has the advantage of having excellent flame retardant properties, even among V-0 grades, as a result of the UL-94 vertical flame retardant test.

[0107] According to one embodiment of the present invention, the density of the polyurethane foam is 0.1 g / cm 3 More than 0.5g / cm 3 Below, 0.1g / cm 3 More than 0.3g / cm 3or less than 0.1g / cm 3 More than 0.2g / cm 3 When the density of the polyurethane foam is adjusted to fall within this range, effective adsorption characteristics can be achieved due to adhesion and excellent repulsion characteristics when applied to a device, while costs can be reduced, making it economical and reducing the weight of the battery.

[0108] According to one embodiment of the present invention, the CFD of the polyurethane foam is 0.05 to 0.18 kg / cm 2 When the CFD of the polyurethane foam is within the above range, when the polyurethane foam is applied to a battery cell, the volume change caused by the expansion of the battery is buffered to maintain a constant volume, thereby improving product stability.

[0109] According to one embodiment of the present invention, the polyurethane foam may have a thickness of 0.1 mm or more and 10 mm or less. Specifically, the polyurethane foam may have a thickness of 0.1 mm or more and 5 mm or less. When the thickness of the polyurethane foam is adjusted to be within the above range, adhesion and shock absorption can be facilitated when the polyurethane foam is applied to a device.

[0110] According to an embodiment of the present invention, the polyurethane foam may be a packing material or a sealing material between cells of an automobile battery.

[0111] Hereinafter, the present invention will be described in detail with reference to examples in order to specifically explain the present invention. However, the examples according to the present invention can be modified into various different forms, and the scope of the present invention is not to be construed as being limited to the examples described below. The examples in the present specification are provided to more completely explain the present invention to those having average knowledge in the art. EXAMPLES

[0112] Manufacture of polyol compounds Production Example 1: Production of the first polyol compound A mixture containing 50 parts by weight of polypropylene glycol having a number average molecular weight of 4,000 g / mol, a viscosity of 1,300 mPa·s, and a heat release capacity of 553 J / g·K and 50 parts by weight of polypropylene glycol having a number average molecular weight of 2,000 g / mol, a viscosity of 300 mPa·s, and a heat release capacity of 553 J / g·K was prepared and then polymerized to produce a first polyol compound having a viscosity of 730 mPa·s and a glass transition temperature of -71°C.

[0113] Production Example 2: Production of second polyol compound In a reactor where nitrogen is refluxed, 10 kg of PEG-PPG copolymer (SC2204; KPX Chemical) having a number average molecular weight of 2,000 g / mol was added, along with H12-MDI (Evonik) and glycerol in the molar ratio relative to SC2204 as shown in Table 2 below. The temperature was then raised to 60°C, and 40 ppm of catalyst (dibutyltin dilaurate) was added. After stirring for 4 hours, it was confirmed by FT-IR that the isocyanate peak had disappeared, and the reaction was terminated to produce a second polyol compound as shown in Table 2 below.

[0114] [Table 2]

[0115] In Table 2, the molar ratio of H12-MDI to glycerol is based on 1 mole of SC2204. As can be seen from Table 2, in the case of Preparation Example 2-3, a polyol having a linear structure was formed without using a chain extender (glycerol) having three or more functional groups. In addition, in the case of Preparation Example 2-4, the content of the multifunctional isocyanate compound (H12-MDI) and the content of the chain extender (glycerol) having three or more functional groups were too high, so gelation occurred and a polyol compound could not be formed. Furthermore, in the case of Preparation Example 2-5, the content of the multifunctional isocyanate compound (H12-MDI) was high, and the viscosity increased significantly, forming a polyol that was difficult to blend with other compositions.

[0116] Production Example 3: Production of the third polyol compound In a reactor where nitrogen is refluxed, 10 kg of polycarbonate diol (T5650E; Aksai Kasai Chemical) with a number average molecular weight of 500 g / mol and XDI (Takenate 600, Mitsui Chemical) were added in the molar ratio to T5650E as shown in Table 3 below. The temperature was then raised to 60°C, and 40 ppm of catalyst (dibutyltin dilaurate) was added. After stirring for 4 hours, it was confirmed by FT-IR that the isocyanate peak had disappeared, and the reaction was terminated to produce a third polyol compound with a heat release capacity of 400 J / g K as shown in Table 3 below.

[0117] [Table 3]

[0118] In Table 3, the molar ratio of XDI is based on 1 mole of T5650E. As can be seen from Table 3, in Preparation Example 3-1, the content of the polyfunctional isocyanate compound (XDI) was too high, and a polyol with an excessively high viscosity was produced, which had poor compatibility with other components and caused phase separation, making it difficult to produce a flame-retardant polyurethane foam. In addition, in Preparation Example 3-1, the internal hydrogen bonds were too strong, and the self-cohesion was high, so there was a problem that mixing with the first polyol compound and the second polyol compound was not performed well.

[0119] Example 1: Preparation of polyurethane foam The first polyol-based compound was prepared in the above-mentioned Preparation Example 1, the second polyol-based compound was prepared in the above-mentioned Preparation Example 2, and the third polyol-based compound was prepared in the above-mentioned Preparation Example 3.

[0120] In addition, a mixture of aluminum phosphate (Al phosphate) and flame-retardant melamine powder (melamine cyanurate; MCA) was prepared as a flame retardant, carbon black was prepared as a dye, L-626 (Momentive), a polydimethylsiloxane substituted with polyalkyl oxide, was prepared as a foam stabilizer, LC5615 (Momentive), a nickel-based catalyst, was prepared as a catalyst, and H12-MDI (Kumho Mitsui Chemicals) was prepared as an isocyanate-based curing agent.

[0121] Then, 70 parts by weight of the first polyol compound, 10 parts by weight of the second polyol compound, and 20 parts by weight of the third polyol compound were mixed to prepare a polyol mixture, which was then placed in a stainless steel mixing vessel equipped with a stirrer capable of high-speed stirring up to 2000 rpm, and stirred uniformly at room temperature. Then, 25 parts by weight of flame retardant, 2 parts by weight of carbon black, and 15 parts by weight of calcium carbonate were added to 100 parts by weight of the polyol mixture, and dispersed well. Then, 2 parts by weight of foam stabilizer and 2 parts by weight of catalyst were added to 100 parts by weight of the polyol mixture, and stirred at high speed for about 1 hour or more to prepare a uniform composition. At this time, the inflow of moisture was suppressed as much as possible, as it inhibits the urethane reaction.

[0122] Furthermore, the prepared composition, isocyanate-based curing agent, and liquid nitrogen were simultaneously fed to a high-speed mixing head using a metering pump at a volume ratio of liquid nitrogen to the total weight of the prepared composition and isocyanate-based curing agent of 4:1. At this time, 28 parts by weight of the isocyanate-based curing agent was added to 100 parts by weight of the polyol mixture, and nitrogen gas was fed while adjusting the density and hardness. The three components were uniformly mixed to prepare a polyurethane foam composition.

[0123] The polyurethane foam composition thus prepared is then coated on a polyester film and cured at a high temperature in the range of about 120 to 150°C in a reaction curing device to obtain a polyurethane foam having a density of 0.2 g / cm. 3A polyurethane foam sheet having a thickness of 3.0 mm was produced.

[0124] Examples 2 to 3 and Comparative Example 1 A polyurethane foam sheet was prepared in the same manner as in Example 1, except that the contents of carbon black, calcium carbonate, foam stabilizer, and catalyst were adjusted to prepare a polyurethane foam composition as shown in Table 4 below.

[0125] Example 4 A polyurethane foam sheet was produced in the same manner as in Example 3, except that a polyurethane foam composition was produced by simultaneously supplying the prepared composition and the isocyanate-based curing agent to a high-speed mixing head at a volume ratio of 2:1 to the total weight of the prepared composition and the isocyanate-based curing agent.

[0126] Adsorption pressure measurement The polyurethane foam sheets produced in Examples 1 to 4 and Comparative Example 1 were cut and placed in cartridges of an automated device (LG Chem), and a vacuum was applied to the vacuum suction pad to measure the suction force when the polyurethane foam and the vacuum pad were adsorbed. The results are shown in Table 4 below.

[0127] [Table 4]

[0128] In Table 4, the contents of the flame retardant, carbon black, calcium carbonate, foam stabilizer, catalyst, and isocyanate curing agent are based on 100 parts by weight of the polyol mixture. Referring to Table 4, it can be seen that the polyurethane foam sheets produced in Examples 1 to 4 using polyurethane foam compositions containing 15 or 20 parts by weight of calcium carbonate have high adsorption pressure and excellent vacuum adsorption properties.

[0129] In contrast, the polyurethane foam sheet prepared in Comparative Example 1 using a polyurethane foam composition containing 30 parts by weight of excess calcium carbonate had an adsorption pressure of only 45 kPa, which resulted in poor adsorption during the battery pack assembly process, which could lead to product defects.

[0130] Therefore, it can be seen that the polyurethane foam composition according to one embodiment of the present invention can provide a polyurethane foam with excellent adsorption properties. In particular, the polyurethane foam has a high adsorption pressure of about 53 kPa or more, and thus has excellent adsorption properties.

Claims

1. a polyol mixture comprising: a first polyol compound which is a polyether polyol and has a glass transition temperature of −50° C. or lower; a second polyol compound which contains at least three functional groups reactive with an isocyanate group and has a weight average molecular weight of 5,000 g / mol or more and 30,000 g / mol or less; and a third polyol compound which is a polymer of a third mixture containing a polyol and a polyfunctional isocyanate compound and has a heat release capacity of 500 J / g·K or less; an isocyanate-based curing agent; and Contains filler, The filler is contained in an amount of 10 parts by weight or more and 20 parts by weight or less relative to 100 parts by weight of the polyol mixture, the second polyol-based compound is a polymer of a second mixture including a polyether-based polyol; a polyfunctional isocyanate-based compound; and a chain extender including three or more functional groups reactive with an isocyanate group; In the second mixture, a molar ratio of the polyether polyol to the polyfunctional isocyanate compound is 1:0.5 or more and 1:0.95 or less, In the second mixture, a molar ratio of the polyether polyol to the chain extender is 1:0.1 or more and 1:0.45 or less; A polyurethane foam composition, wherein in the third mixture, the molar ratio of the polyol having a heat release capacity of 500 J / g·K or less to the polyfunctional isocyanate compound is 1:0.05 or more and 1:0.25 or less.

2. 10. The polyurethane foam composition of claim 1, wherein the filler comprises one or more of silicon dioxide, silica, ATH, and calcium carbonate.

3. The polyurethane foam composition according to claim 1 or 2, wherein the content of the first polyol compound is 60 parts by weight or more and 75 parts by weight or less based on 100 parts by weight of the polyol mixture.

4. The polyurethane foam composition according to claim 1 , wherein the content of the second polyol compound is 5 parts by weight or more and 20 parts by weight or less per 100 parts by weight of the polyol mixture.

5. The polyurethane foam composition according to claim 1 , wherein the content of the third polyol compound is 15 parts by weight or more and 50 parts by weight or less per 100 parts by weight of the polyol mixture.

6. 6. The polyurethane foam composition of claim 1, further comprising additives including one or more of a flame retardant, a catalyst, a crosslinker, and a dye.

7. The polyurethane foam composition according to claim 6 , wherein the content of the flame retardant is 20 parts by weight or more and 50 parts by weight or less based on 100 parts by weight of the polyol mixture.

8. A polyurethane foam comprising the cured polyurethane foam composition according to any one of claims 1 to 7.

9. The polyurethane foam according to claim 8, having an adsorption pressure of 50 kPa or more.

10. Density is 0.1 g / cm ３ 0.5g / cm or more ３ 10. The polyurethane foam according to claim 8 or 9, wherein:

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