Polyurethane foam composition and polyurethane foam containing the cured product thereof

Abstract

The present invention relates to a polyurethane foam composition and a polyurethane foam comprising a 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 on September 9, 2020, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety.

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

[0003] Polyurethane foam is relatively inexpensive, easily moldable, and highly resilient, making it widely used in consumer goods and automotive parts. However, when used in electronic products and the like, a problem arises: if the flammable polyurethane foam ignites due to a short circuit, it can burn uncontrollably, causing damage to the product or even fire or explosion.

[0004] To overcome this problem, a method of imparting flame retardancy to polyurethane foam by laminating a flame-retardant sheet or plate onto one surface of the polyurethane foam is widely used. However, since this method does not fundamentally impart flame retardancy to polyurethane foam, the flame retardant effect is limited. Furthermore, this method complicates the production process and increases production costs. Furthermore, flame retardants composed of halogen compounds, such as bromine compounds or chlorine compounds, have been added to polyurethane foam to impart inherent flame retardancy. However, these flame retardants can cause problems for humans and the environment due to the toxic gases released during combustion.

[0005] Polyurethane foam is also used as a buffer to mitigate the volume changes of battery cells during charging and discharging. Typically, battery cells are used in a manner that causes their volume to increase during charging. In this case, polyurethane foam is used as a sealant between battery cells during battery cell production to mitigate battery volume expansion and prevent problems such as explosions.

[0006] In the automated process of assembling battery packs, polyurethane foam is drawn into the vacuum cups during the automated process. However, if the suction pressure is too low, the polyurethane foam cannot be used in the automated process because the polyurethane foam cannot be drawn into the vacuum cups at the required pressure, and thus the product cannot be transferred. Furthermore, if the suction pressure is too low, the cups and the polyurethane foam may separate during the tape lamination process.

[0007] In order to increase the suction pressure, attempts have been made to increase the density of polyurethane foam, but this also raises problems in terms of cost and the process after suction.

[0008] In order to solve the above problems, it is necessary to develop foams with excellent flame retardancy and inhalation properties as well as low density. Summary of the Invention

[0009] Technical issues

[0010] An object of the present invention is to provide a polyurethane foam composition and a polyurethane foam comprising a cured product thereof.

[0011] However, objects to be achieved by the present invention are not limited to the above objects, and other objects not mentioned herein will be clearly understood by those skilled in the art from the following description.

[0012] Technical Solution

[0013] One embodiment of the present invention provides a polyurethane foam composition, comprising: a polyol mixture comprising a first polyol-based compound having a glass transition temperature of −50° C. or lower, a second polyol-based compound having a weight average molecular weight of 5,000 to 30,000 g / mol and comprising at least three functional groups reactive with isocyanate groups, and a third polyol-based compound having an exothermic capacity of 500 J / g·K or lower; an isocyanate-based curing agent; and a filler, wherein the filler is contained in an amount of 10 to 20 parts by weight based on 100 parts by weight of the polyol mixture.

[0014] Another embodiment of the present invention provides a polyurethane foam including a cured product of the polyurethane foam composition.

[0015] Beneficial effects

[0016] The polyurethane foam composition according to one embodiment of the present invention may provide a polyurethane foam having a low density while being inhaled under a high suction pressure.

[0017] Since the polyurethane foam according to one embodiment of the present invention is sucked at a high suction pressure, it can facilitate a process of laminating a tape using a vacuum suction cup during an automated process and can be conveniently transferred.

[0018] When the polyurethane foam according to one embodiment of the present invention is applied between battery cells, it may exhibit excellent dimensional stability against volume changes of the battery, excellent stress absorption capability for absorbing vibrations and impacts, excellent resilience, and high fire resistance.

[0019] The effects of the present invention are not limited to the above-mentioned effects, and effects not mentioned herein will be clearly understood by those skilled in the art from this specification and the accompanying drawings. DETAILED DESCRIPTION

[0020] Throughout the present specification, it should be understood that, unless otherwise stated, when any part is referred to as “comprising” any component, it does not exclude additional components but may further include additional components.

[0021] Throughout this specification, the unit "parts by weight" may refer to a weight ratio between components.

[0022] Throughout the present specification, "A and / or B" means "A and B" or "A or B".

[0023] Throughout this specification, the "weight average molecular weight" and "number average molecular weight" of any compound can be calculated using the molecular weight and molecular weight distribution of the compound. Specifically, the molecular weight and molecular weight distribution of the compound can be obtained by placing tetrahydrofuran (THF) and the compound in a 1 ml glass vial to prepare a test sample in which the concentration of the compound is 1 wt %; filtering the standard sample (polystyrene) and the test sample through a filter (pore size: 0.45 mm); injecting each sample filtrate into a GPC syringe; and comparing the elution time of the test sample with the calibration curve of the standard sample. At this time, Infinity II 1260 (Agilent Technologies, Inc.) can be used as a measuring instrument, and the flow rate and column temperature can be set to 1.00 mL / min and 40.0°C, respectively.

[0024] Throughout this specification, "glass transition temperature (Tg)" can be measured using differential scanning calorimetry (DSC). Specifically, the glass transition temperature can be measured using a differential scanning calorimeter (DSC, DSC-STAR3, METTLER TOLEDO) by performing two cycles of heating a sample in a temperature range of -60°C to 150°C at a heating rate of 5°C / min within the temperature range, and then measuring the midpoint of the DSC curve drawn from the points with thermal changes.

[0025] Throughout this specification, the viscosity of any compound may be a value measured at a temperature of 25° C. using a Brookfield viscometer.

[0026] Hereinafter, this specification will be described in more detail.

[0027] One embodiment of the present invention provides a polyurethane foam composition, comprising: a polyol mixture comprising a first polyol-based compound having a glass transition temperature of −50° C. or lower, a second polyol-based compound having a weight average molecular weight of 5,000 to 30,000 g / mol and comprising at least three functional groups reactive with isocyanate groups, and a third polyol-based compound having an exothermic capacity of 500 J / g·K or lower; an isocyanate-based curing agent; and a filler, wherein the filler is contained in an amount of 10 to 20 parts by weight based on 100 parts by weight of the polyol mixture.

[0028] The polyurethane foam composition according to one embodiment of the present invention may provide a polyurethane foam having excellent suction characteristics.

[0029] Hereinafter, each component included in the polyurethane foam composition according to one embodiment of the present invention will be described in detail.

[0030] (1) First polyol-based compound

[0031] According to one embodiment of the present invention, the glass transition temperature of the first polyol-based compound may be -50°C or lower. Specifically, the glass transition temperature of the first polyol-based compound may be -80°C to -50°C, or -75°C to -60°C. When the glass transition temperature of the first polyol-based compound is within the above range, the polyurethane foam including the cured product of the polyurethane foam composition may have high rebound properties and compression recovery properties.

[0032] Furthermore, the viscosity of the first polyol-based compound at 25°C may be 2,000 mPa·s or less. Specifically, the viscosity of the first polyol-based compound at 25°C may be 200 mPa·s to 2,000 mPa·s. When the viscosity of the first polyol-based compound is controlled within the above range, there is an advantage that the dispersibility and processability of the raw materials can be improved during the production of polyurethane foam.

[0033] 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 less and a polyalkylene oxide unit, and its viscosity at 25°C may be 2,000 mPa·s or less.

[0034] In addition, the first polyol-based compound may include at least two functional groups that react with isocyanate groups. The functional group that reacts with isocyanate groups may refer to a functional group that forms a urethane bond with the isocyanate groups. Specifically, the functional group that reacts with isocyanate groups may be a hydroxyl group, an amine group, a thiol group, or a carboxyl group. More specifically, the first polyol-based compound may have a hydroxyl group bonded to both ends of the main chain, and at least one of the hydroxyl group, the amine group, the thiol group, and the carboxyl group may be included in the side chain of the first polyol-based compound.

[0035] According to one embodiment of the present invention, the first polyol-based compound may be a polymer of a first mixture including at least one of an ether-based polyol, an ester-based polyol, and a chain extender.

[0036] As the ether-based polyol, ester-based polyol, and chain extender, those used in the art can be used. For example, as the ether-based polyol, polypropylene glycol, polytetramethylene glycol, etc. can be used, as the ester-based polyol, polycaprolactone polyol, etc. can be used, and as the chain extender, butanediol, etc. can be used.

[0037] According to one embodiment of the present invention, the content of the first polyol-based compound may be 60 to 75 parts by weight based on 100 parts by weight of the polyol mixture. Specifically, the content of the first polyol-based compound may be 62.5 to 72.5 parts by weight, 65 to 70 parts by weight, or 67 to 73 parts by weight based on 100 parts by weight of the polyol mixture. When the content of the first polyol-based compound is controlled within the above range, the compression recovery characteristics of the polyurethane foam comprising the cured product of the polyurethane foam composition can be improved.

[0038] In this specification, the term "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. In addition, the term "polyol mixture" may also refer to a mixture consisting of the first polyol-based compound, the second polyol-based compound, and the third polyol-based compound.

[0039] (2) Second polyol-based compound

[0040] According to one embodiment of the present invention, the second polyol-based compound may include at least three functional groups that react with isocyanate groups. The functional group that reacts with isocyanate groups may refer to a functional group that forms a urethane bond with the isocyanate groups. Specifically, the functional group that reacts with the isocyanate groups may be a hydroxyl group, an amine group, a thiol group, or a carboxyl group.

[0041] According to one embodiment of the present invention, the second polyol-based compound may have a branched structure. Specifically, the second polyol-based compound may be a compound in which hydroxyl groups are bonded to both ends and one or more functional groups reactive with isocyanate groups are bonded to the main chain to form side chains. Specifically, compared to a polyol having a linear structure in which only hydroxyl groups are bonded to both ends, the second polyol-based compound contains at least three functional groups reactive with isocyanate groups, which allows for the formation of a denser network structure during urethane polymerization.

[0042] 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 the backbone of the polyurethane foam, and when the weight average molecular weight of the second polyol-based compound is within the above range, the ability of the polyurethane foam to recover from compression can be effectively improved.

[0043] According to one embodiment of the present invention, the viscosity of the second polyol-based compound at 25° C. may be 20,000 mPa·s to 200,000 mPa·s. Specifically, the viscosity of the second polyol-based compound at 25° C. may be 30,000 mPa·s to 180,000 mPa·s, 35,000 mPa·s to 150,000 mPa·s, 50,000 mPa·s to 120,000 mPa·s, 60,000 mPa·s to 100,000 mPa·s, or 35,000 mPa·s to 70,000 mPa·s. When the viscosity of the second polyol-based compound is within the above range, the second polyol-based compound can be uniformly dispersed with other materials in the polyurethane foam composition, thereby producing a polyurethane foam with uniform quality.

[0044] According to one embodiment of the present invention, the second polyol-based compound may be a polyether-based polyol including at least three functional groups reactive with an isocyanate group and having a weight average molecular weight of 5,000 to 30,000 g / mol and a viscosity at 25° C. of 20,000 to 200,000 mPa·s.

[0045] According to one embodiment of the present invention, the second polyol-based compound may be a polymer of a second mixture comprising a polyether-based polyol, a polyfunctional isocyanate-based compound, and a chain extender comprising at least three functional groups reactive with isocyanate groups.

[0046] According to one embodiment of the present invention, the polyether-based polyol in the second mixture may be derived from polyalkylene oxide. Specifically, the polyether-based polyol in the second mixture may include at least one of polyethylene glycol (PEG), polypropylene glycol (PPG), polyethylene glycol-polypropylene glycol (PEG-PPG) copolymer, and poly(tetramethylene ether) glycol (PTMG).

[0047] According to one embodiment of the present invention, the molar ratio of the polyether-based polyol to the multifunctional isocyanate-based compound in the second mixture may be 1:0.5 to 1:1. Specifically, the molar ratio of the polyether-based polyol to the multifunctional isocyanate-based compound in the second mixture may be 1:0.6 to 1:0.95, or 1:0.65 to 1:0.9.

[0048] When the content of the polyfunctional isocyanate-based compound in the second mixture is within the above range, the compatibility of the polyfunctional isocyanate-based compound with other components can be increased by preventing excessive viscosity increase in the production of the second polyol-based compound, and gelation can be prevented.

[0049] According to one embodiment of the present invention, the polyfunctional isocyanate-based compound in the second mixture may include two isocyanate groups. In addition, the polyfunctional isocyanate-based compound in the second mixture may include at least one of an aromatic polyfunctional isocyanate compound, an alicyclic polyfunctional isocyanate compound, and an aliphatic polyfunctional isocyanate compound.

[0050] Specifically, the aromatic polyfunctional isocyanate compound may include at least one of the following: 2,4-toluene diisocyanate (TDI), 2,6-toluene diisocyanate (TDI), m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-methylene diphenyl diisocyanate (MDI), 2,4'-methylene diphenyl diisocyanate (MDI), 2,2'-methylene diphenyl diisocyanate (MDI), xylene diisocyanate (XDI), 3,3'-dimethyl-4,4'-biphenylene diisocyanate, and 3,3'-dimethoxy-4,4'-biphenylene diisocyanate.

[0051] In addition, the alicyclic polyfunctional isocyanate compound may include at least one of the following: 4,4'-methylene dicyclohexyl diisocyanate (H12-MDI), cyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI), dicyclohexylmethane-4,4'-diisocyanate, hydrogenated xylene diisocyanate (H6-XDI), and methylcyclohexane diisocyanate.

[0052] Furthermore, 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.

[0053] According to one embodiment of the present invention, a molar ratio of the polyether-based polyol to the chain extender in the second mixture may be 1:0.1 to 1:0.45.

[0054] Specifically, the molar ratio of the polyether-based polyol to the chain extender may be 1:0.2 to 1:0.4, or 1:0.25 to 1:0.35, more specifically 1:0.3.

[0055] When the content of the chain extender in the second mixture is within the above range, there is an advantage that excellent compression recovery properties can be achieved by forming appropriate crosslinks in the polyurethane foam.

[0056] According to one embodiment of the present invention, the chain extender in the second mixture may be a compound comprising at least three functional groups reactive with isocyanate groups. In addition, the number of functional groups in the chain extender may be 3 to 10, or 3 to 5.

[0057] According to one embodiment of the present invention, the chain extender in the second mixture may include at least one of the following compounds:

[0058]

[0059] According to one embodiment of the present invention, the content of the second polyol-based compound may be 5 to 20 parts by weight based on 100 parts by weight of the polyol mixture. Specifically, the content of the second polyol-based compound may be 5 to 15 parts by weight based on 100 parts by weight of the polyol mixture.

[0060] When the content of the second polyol-based compound is within the above range, the softness of the polyurethane foam formed using the polyurethane foam composition can be maintained, and excellent resilience of the polyurethane foam can be achieved. In addition, when the content of the second polyol-based compound is controlled within the above range, the durability of the polyurethane foam can be ensured by minimizing the loss of the ability to recover from compression.

[0061] (3) Third polyol-based compound

[0062] According to one embodiment of the present invention, the third polyol-based compound may be a polyol having an exothermic capacity of 500 J / g·K or less, or a polymer of a third mixture comprising a polyol having an exothermic capacity of 500 J / g·K or less and a polyfunctional isocyanate-based compound.

[0063] According to one embodiment of the present invention, the third polyol-based compound itself may have flame retardant properties, thereby improving the flame retardant performance of the polyurethane foam.

[0064] According to one embodiment of the present invention, the third polyol-based compound may include at least one of polycarbonate diol having an exothermic capacity of 500 J / g·K or less and polydimethylsiloxane diol having an exothermic capacity of 500 J / g·K or less.

[0065] According to one embodiment of the present invention, the polyol having an exothermic capacity of 500 J / g·K or less may be a polyol having a limiting oxygen index value of 21% or more.

[0066] According to one embodiment of the present invention, the third polyol-based compound may be a polymer formed using a third mixture comprising a polyol having an exothermic capacity of 500 J / g·K or less and a polyfunctional isocyanate-based compound. That is, the polymer may have an exothermic capacity of 500 J / g·K or less. Furthermore, the third polyol-based compound may be a polymer formed using a third mixture comprising a polyol having an exothermic capacity of 500 J / g·K or less and a limiting oxygen index value of 21% or greater and a polyfunctional isocyanate-based compound. That is, the polymer formed using the third mixture may have an exothermic capacity of 500 J / g·K or less and a limiting oxygen index value of 21% or greater.

[0067] According to one embodiment of the present invention, the third polyol-based compound can satisfy a heat release capacity of 500 J / g·K or less, or a heat release capacity of 500 J / g·K or less and a limiting oxygen index value of 21% or greater, and thus the third polyol-based compound itself can have flame retardant properties, thereby improving the flame retardant properties of the polyurethane foam.

[0068] According to one embodiment of the present invention, the polyfunctional isocyanate-based compound in the third mixture can be used to improve the compatibility of the third polyol-based compound with other components. In addition, the polyfunctional isocyanate-based compound in the third mixture can be the same material as the polyfunctional isocyanate-based compound in the second mixture.

[0069] According to one embodiment of the present invention, in the third mixture, the molar ratio of the polyol having an exothermic capacity of 500 J / g·K or less to the polyfunctional isocyanate-based compound may be 1:0.05 to 1:0.25. Specifically, the molar ratio of the polyol having an exothermic capacity of 500 J / g·K or less to the polyfunctional isocyanate-based compound may be 1:0.05 to 1:0.15, or 1:0.07 to 0.12, more specifically 1:0.1.

[0070] When the content of the polyfunctional isocyanate-based compound in the third mixture is within the above range, a polymer formed using the third mixture may have improved compatibility with other compositions.

[0071] According to one embodiment of the present invention, the content of the third polyol-based compound may be 15 to 50 parts by weight based on 100 parts by weight of the polyol mixture. Specifically, the content of the third polyol-based compound may be 25 to 40 parts by weight, or 25 to 35 parts by weight based on 100 parts by weight of the polyol mixture.

[0072] When the content of the third polyol-based compound is controlled within the above range, compatibility with other materials in the polyurethane foam composition can be ensured. Furthermore, when the content of the third polyol-based compound is within the above range, flame retardancy corresponding to V-0 can be achieved in accordance with the UL-94 vertical flame retardancy test for polyurethane foam, while minimizing hardening of the polyurethane foam.

[0073] According to one embodiment of the present invention, the viscosity of the third polyol-based compound may be 1,000 to 7,000 mPa·s, or 1,500 to 5,000 mPa·s. When the viscosity of the third polyol-based compound is within the above range, there is an advantage in ensuring compatibility of the third polyol-based compound with other components in the polyurethane foam composition.

[0074] According to one embodiment of the present invention, the total content of the second polyol-based compound and the third polyol-based compound may be 30 to 60 parts by weight based on 100 parts by weight of the polyol mixture. Specifically, the total content of the second polyol-based compound and the third polyol-based compound may be 30 to 50 parts by weight, or 30 to 45 parts by weight, or 30 to 40 parts by weight based on 100 parts by weight of the polyol mixture.

[0075] When the total content of the second polyol-based compound and the third polyol-based compound is controlled within the above range, flame retardant properties and compression properties of a polyurethane foam including a cured product of the polyurethane foam composition may be effectively improved.

[0076] (4) Filler

[0077] The polyurethane foam composition according to one embodiment of the present invention includes a filler. The filler included in the polyurethane foam composition can increase the hardness of the polyurethane foam and the suction pressure when the polyurethane foam is inhaled, and can maintain the compression force deformation (CFD) of the polyurethane foam at an appropriate level.

[0078] According to one embodiment of the present invention, the filler may include silica silica At least one of ATH and calcium carbonate. In particular, the filler may preferably include calcium carbonate, but is not limited thereto.

[0079] According to one embodiment of the present invention, the filler may be 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. When the filler is included in an amount within the above range, the polyurethane foam product can have excellent workability in an automated process due to the high vacuum suction pressure while maintaining its appropriate hardness. In this case, an appropriate level of CFD can be achieved while the polyurethane foam has reduced compression set, a smooth surface, and an excellent appearance.

[0080] Compression force deformation (CFD) is a parameter that indicates the rebound force generated when the measurement target is compressed. Specifically, CFD can be evaluated by cutting polyurethane foam into a size of 5 cm*5 cm and measuring the rebound force generated when the cut polyurethane foam is compressed using a device such as UTM. A suitable value of CFD can be about 0.05 kg / cm 2 Up to 0.18kg / cm 2 When the polyurethane foam has an appropriate level of CFD value, the polyurethane foam applied to the battery cell can maintain the volume of the battery cell at a constant level by buffering the volume change caused by battery expansion, thereby improving product stability.

[0081] (5) Foam stabilizer and gas source for foam formation

[0082] The polyurethane foam composition according to one embodiment of the present invention may include a foam stabilizer. As the foam stabilizer added to produce the foam shape, any foam stabilizer commonly used in the production of polyurethane foam can be applied. Specifically, the foam stabilizer may include at least one of a polysiloxane-based foam stabilizer, a silicone-based foam stabilizer, a fluorine-based foam stabilizer, an ionic surfactant, and a nonionic surfactant. More specifically, the foam stabilizer may include a polyalkyloxy-substituted polydimethylsiloxane. However, the foam stabilizer is not limited thereto, and any foam stabilizer commonly used in the art may be used. When using a foam stabilizer, the foaming gas can form a suitable foam structure of the polyurethane foam and maintain the stable dispersion of the gas when solidifying into the polyurethane foam, thereby forming pores with uniform size and distribution.

[0083] According to one embodiment of the present invention, the foam stabilizer may be included in an amount of 0.5 to 10 parts by weight, 1 to 5 parts by weight, or 2 to 4 parts by weight, based on 100 parts by weight of the polyol mixture.

[0084] The polyurethane foam composition according to one embodiment of the present invention may include a foam-forming gas source. The foam-forming gas source may interact with a foam stabilizer to form cells in the polyurethane foam through foaming.

[0085] The gas for forming the foam is a gas that does not adversely affect the reaction between the polyol-based compound and the isocyanate. As the gas for forming the foam, an inert gas such as dry air and / or nitrogen can be used, but the gas for forming the foam is not limited thereto. The gas source for forming the foam can be a liquid gas such as liquid nitrogen.

[0086] The amount of the foam-forming gas source may vary depending on the desired density of the polyurethane foam.

[0087] (6) Isocyanate-based curing agents

[0088] According to one embodiment of the present invention, the isocyanate-based curing agent may form a polyurethane network by forming a urethane bond with the first to third polyol-based compounds.

[0089] According to one embodiment of the present invention, the isocyanate-based curing agent is a compound containing two or three or more isocyanate groups, and may 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-based curing agent may be the same material as the aromatic isocyanate compound, the alicyclic isocyanate compound, and the aliphatic isocyanate compound in the second mixture, respectively.

[0090] According to one embodiment of the present invention, based on 100 parts by weight of the polyol mixture, the content of the isocyanate-based curing agent can be 20 parts by weight to 35 parts by weight. Specifically, based on 100 parts by weight of the polyol mixture, the content of the isocyanate-based curing agent can be 25 parts by weight to 32.5 parts by weight, 27.5 parts by weight to 30 parts by weight, or 28 parts by weight to 32 parts by weight. When the content of the isocyanate-based curing agent is controlled within the above range, the reaction of forming a urethane bond with the first to third polyol-based compounds contained in the polyol mixture can be effectively carried out.

[0091] (7) Other additives

[0092] According to one embodiment of the present invention, the polyurethane foam composition may further include an additive comprising at least one of a flame retardant, a catalyst, a cross-linking agent, and a dye.

[0093] According to one embodiment of the present invention, the flame retardant may include a halogen-free flame retardant. Specifically, the flame retardant may include a solid or liquid halogen-free phosphorus-based flame retardant. Specifically, according to one embodiment of the present invention, the flame retardant may include at least one selected from phosphates, phosphonates, phosphinates, phosphine oxides, and phosphazenes. Specifically, the flame retardant may be aluminum phosphate. However, the present invention is not limited thereto, and phosphorus-based flame retardants commonly used in the art may be used.

[0094] Halogen-free phosphorus-based flame retardants can react with combustible materials to form a carbonized layer on the polymer surface, which can block the oxygen required for combustion, thereby improving the flame retardancy of polyurethane foam. In addition, halogen-free phosphorus-based flame retardants can react with oxygen in the polymer to dehydrate and carbonize it, and the free radicals generated by the decomposition of phosphoric acid can be used to stabilize -OH and -H, which are active free radicals generated by combustion.

[0095] According to one embodiment of the present invention, the flame retardant may include a mixture of a phosphorus-based flame retardant and flame retardant melamine powder. Specifically, the flame retardant melamine powder may be melamine cyanurate (MCA).

[0096] According to one embodiment of the present invention, based on 100 parts by weight of the polyol mixture, the content of the flame retardant may be 20 to 50 parts by weight. Specifically, based on 100 parts by weight of the polyol mixture, the content of the flame retardant may be 20 to 40 parts by weight, 21 to 30 parts by weight, or 25 to 30 parts by weight.

[0097] When the flame retardant content is within the above range, the heat release capacity of the polyol-based compound in the polyurethane foam composition can be reduced and the limiting oxygen index can be increased. Furthermore, when the flame retardant content is within the above range, the flame retardant can help form carbon (char) in the polyurethane foam polymer during combustion and effectively remove free radicals generated during combustion. Furthermore, when the flame retardant content is within the above range, flame retardancy can be ensured while minimizing degradation of the compression recovery properties of the polyurethane foam.

[0098] According to one embodiment of the present invention, the polyurethane foam composition may include expandable graphite to further improve the flame retardancy of the polyurethane foam.

[0099] According to one embodiment of the present invention, the size of expandable graphite can be 150 μm to 300 μm. Specifically, the size of expandable graphite can be 165 μm to 300 μm, 180 μm to 300 μm or 200 μm to 300 μm. Expandable graphite has a layered crystal structure, and when heated, it can expand to a size of 20 to 400 times its original size to induce the formation of porous carbide during combustion. When the size of expandable graphite is controlled within the above range, the flame retardant properties of polyurethane foam can be effectively improved. Specifically, when the size of expandable graphite is within the above range, with respect to the UL-94 vertical flame retardant test, polyurethane foam can have a flame retardant property corresponding to a V-0 grade. More specifically, with respect to the UL-94 vertical flame retardant test, polyurethane foam meets the flame retardant property corresponding to a V-0 grade, and at the same time, in the UL-94 vertical flame retardant test, the total after-flame time (total after-flame time) of 5 specimens after the first flame application can be less than 2 seconds. That is, the polyurethane foam has an advantage of having excellent flame retardant characteristics corresponding to V-0 grade with respect to the UL-94 vertical flame retardancy test.

[0100] According to one embodiment of the present invention, the size of the expandable graphite may refer to the longest length from one end to the other end of the expandable graphite. In addition, the expandable graphite may include a plurality of expandable graphite particles, and the size of the expandable graphite may be an average value of the sizes of the plurality of expandable graphite particles.

[0101] According to one embodiment of the present invention, the size of the expandable graphite can be measured using any selected particle size measurement method known in the art. For example, the expandable graphite can be imaged using a scanning electron microscope (SEM), and the size of the expandable graphite can be measured using the image.

[0102] According to one embodiment of the present invention, the content of expandable graphite can be greater than 0 parts by weight and less than or equal to 50 parts by weight based on 100 parts by weight of the polyol mixture. Specifically, the content of expandable graphite can be 21 parts by weight to 40 parts by weight, or 21 parts by weight to 30 parts by weight based on 100 parts by weight of the polyol mixture. When the content of expandable graphite is controlled within the above range, the flame retardancy of the polyurethane foam can be improved without reducing the compression recovery force of the polyurethane foam.

[0103] According to one embodiment of the present invention, the weight ratio of the flame retardant to the expandable graphite may be 1:0.8 to 1:1.2, specifically, the weight ratio of the flame retardant to the expandable graphite may be 1:0.9 to 1:1.1, more specifically 1:1.

[0104] When the weight ratio of the flame retardant to the expanded graphite is controlled within the above range, the polyurethane foam formed using the polyurethane foam composition can have flame retardant properties corresponding to V-0 grade. In addition, the polyurethane foam can have excellent flame retardant properties corresponding to V-0 grade among the flame retardant properties.

[0105] According to one embodiment of the present invention, the catalyst may be an amine-based catalyst and / or a metal catalyst. Specifically, the amine-based catalyst may include at least one of the following: a monoamine compound, a diamine compound, a triamine compound, a polyamine compound, a cyclic amine compound, an alcoholamine compound, and an etheramine compound. In addition, the metal catalyst may include at least one of the following: a nickel-based 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.

[0106] According to one embodiment of the present invention, the catalyst may be included in an amount of 0.5 to 10 parts by weight, 1 to 10 parts by weight, or 1 to 5 parts by weight, based on 100 parts by weight of the polyol mixture.

[0107] According to one embodiment of the present invention, the crosslinking agent may be a low molecular weight compound having two or more and four or fewer active hydrogen-containing groups capable of reacting with an isocyanate group and having a number average molecular weight of 50 g / mol to 800 g / mol. Specifically, the crosslinking agent may include at least one of the following: ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, glycerol, trimethylolpropane, triethanolamine, and pentaerythritol.

[0108] According to one embodiment of the present invention, the content of the cross-linking agent may be 1 to 20 parts by weight, or 5 to 15 parts by weight, based on 100 parts by weight of the polyol mixture.

[0109] According to an exemplary embodiment of the present invention, the dye can show the color of the polyurethane foam of the cured product comprising the polyurethane foam composition. As the dye, any dye used in the art can be used without limitation. For example, carbon black can be used.

[0110] The dye may be present in an amount of 1 to 3 parts by weight based on 100 parts by weight of the polyol mixture. When the dye content is within the above range, the polyurethane foam may be imparted with color without adversely affecting the physical properties of the polyurethane foam.

[0111] Another embodiment of the present invention provides a polyurethane foam comprising a cured product of the polyurethane foam composition.

[0112] One embodiment of the present invention provides a polyurethane foam formed using the polyurethane foam composition. The method of producing a polyurethane foam using the polyurethane foam composition can be performed using a generally known method for producing polyurethane foam.

[0113] One embodiment of the present invention provides a polyurethane foam that is inhaled at an inhalation pressure of 50 kPa or more, 50 kPa or more and 95 kPa or less, or 60 kPa to 95 kPa. When the polyurethane foam is inhaled at an inhalation pressure within the above range, the polyurethane foam can have excellent workability in an automated process, and the inhalation pressure can correspond to an appropriate pressure during the process of assembling a battery pack.

[0114] According to one embodiment of the present invention, the polyurethane foam may have flame retardant properties corresponding to a V-0 rating with respect to the UL-94 vertical flame retardant test.

[0115] In the UL-94 vertical flame retardancy test, samples each having a width of 125 ± 25 mm, a length of 13.0 ± 0.5 mm, and a thickness of 2.0 mm were prepared. Five test specimens, each consisting of a set of two samples prepared as described above, were prepared and stored at a temperature of 23 ± 2°C and a humidity of 50 ± 5%. The calorific value used was 37 MJ / m 3 Each sample was burned twice for 10 seconds each time using a blue flame of methane gas (flame height: 20 mm; distance between the lower part of the sample and the end of the burner: 9.5 mm). After the second burning for 10 seconds, the time it took for the flame to disappear (t2) and the time it took for flameless combustion to continue (t3) were measured and given a rating according to the standards shown in Table 1 below.

[0116] [Table 1]

[0117]

[0118]

[0119] According to one embodiment of the present invention, when the polyurethane foam is subjected to the UL-94 vertical flame retardant test, the total afterflame time of five specimens after the first flame application can be less than 2 seconds. Specifically, when the polyurethane foam is subjected to the UL-94 vertical flame retardant test, the total afterflame time of five specimens after burning for 10 seconds can be less than 2 seconds. According to one embodiment of the present invention, when the polyurethane foam is subjected to the UL-94 vertical flame retardant test, the total afterflame time of five specimens after the second flame application can be less than 5 seconds. Specifically, when the polyurethane foam is subjected to the UL-94 vertical flame retardant test, the total afterflame time of five specimens after burning twice (each for 10 seconds) can be less than 5 seconds after the second burning.

[0120] Therefore, the polyurethane foam according to one embodiment of the present invention has an advantage of having excellent flame retardant characteristics corresponding to V-0 grade among flame retardant characteristics with respect to the UL-94 vertical flame retardant test.

[0121] According to one embodiment of the present invention, the density of the polyurethane foam may be 0.1 g / cm 3 to 0.5g / cm 3 , 0.1g / cm 3 to 0.3g / cm 3 , or 0.1g / cm 3 to 0.2g / cm 3 When the density of the polyurethane foam is controlled within the above range, the polyurethane foam can be effectively absorbed due to its excellent adhesion and rebound properties when applied between battery cells, which can economically reduce costs and can help reduce the weight of the battery.

[0122] According to one embodiment of the present invention, the CFD of the polyurethane foam may be 0.05 kg / cm 2 Up to 0.18kg / cm 2 When the CFD of the polyurethane foam is within the above range, the polyurethane foam can maintain the volume of the battery cell at a constant level by buffering the volume change caused by battery expansion when applied between the battery cells, thereby improving product stability.

[0123] According to one embodiment of the present invention, the thickness of the polyurethane foam may be 0.1 mm to 10 mm. Specifically, the thickness of the polyurethane foam may be 0.1 mm to 5 mm. When the thickness of the polyurethane foam is controlled within the above range, the polyurethane foam can have excellent adhesion to the device when applied to the device and can easily absorb impact.

[0124] According to one embodiment of the present invention, polyurethane foam can be used as a packaging material. In addition, according to one embodiment of the present invention, polyurethane foam can be used as a sealing material between vehicle battery cells.

[0125] Hereinafter, the present invention will be described in detail with reference to embodiments. However, embodiments according to the present invention may be modified into various forms, and the scope of the present invention is not to be construed as being limited to the embodiments described below. The embodiments of this specification are provided to more fully illustrate the present invention to those skilled in the art.

[0126] Embodiments of the invention

[0127] Production of polyol-based compounds

[0128] Production Example 1: Production of the first polyol-based compound

[0129] A mixture including 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 an exothermic 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 an exothermic capacity of 553 J / g·K was prepared and then polymerized to produce a first polyol-based compound having a viscosity of 730 mPa·s and a glass transition temperature of -71°C.

[0130] Production Example 2: Production of a second polyol-based compound

[0131] 10 kg of a PEG-PPG copolymer (SC2204; KPX Chemical) having a number average molecular weight of 2000 g / mol, H12-MDI (Evonik), and glycerin at the respective molar ratios relative to SC2204 shown in Table 2 below were introduced into a reactor under nitrogen reflux. The contents of the reactor were heated to 60° C., and 40 ppm of a catalyst (dibutyltin dilaurate) was added thereto, followed by stirring for 4 hours. The reaction was terminated when the isocyanate peak disappeared as determined by FT-IR, thereby producing the second polyol-based compound shown in Table 2 below.

[0132] [Table 2]

[0133]

[0134] In Table 2 above, the molar ratios of H12-MDI to glycerol are relative to 1 mol of SC2204. As can be seen in Table 2 above, in Production Example 2-3, a polyol having a linear structure was formed because a chain extender (glycerol) having three or more functional groups was not used. In addition, in Production Example 2-4, the content of the polyfunctional isocyanate-based compound (H12-MDI) and the content of the chain extender (glycerol) having three or more functional groups were too high, causing gelation and thus failing to form a polyol-based compound. In addition, in Production Example 2-5, the content of the polyfunctional isocyanate-based compound (H12-MDI) was high, causing a significant increase in viscosity, and thus forming a polyol that was difficult to mix with other components.

[0135] Production Example 3: Production of a third polyol-based compound

[0136] 10 kg of a polycarbonate diol (T5650E; Asahi Kasei Chemical) having a number average molecular weight of 500 g / mol and XDI (Takenate 600, Mitsui Chemical) at various molar ratios relative to T5650E as shown in Table 3 below were introduced into a reactor under nitrogen reflux. The contents of the reactor were heated to 60°C, and 40 ppm of a catalyst (dibutyltin dilaurate) was added, followed by stirring for 4 hours. The reaction was terminated when the isocyanate peak disappeared as determined by FT-IR, thereby producing a third polyol-based compound having an exothermic capacity of 400 J / g·K as shown in Table 3 below.

[0137] [Table 3]

[0138]

[0139] In Table 3 above, the molar ratio of XDI is relative to 1 mole of T5650E. As can be seen from Table 3, in Production Example 3-1, the content of the polyfunctional isocyanate-based compound (XDI) was too high, resulting in a polyol with excessively high viscosity and poor compatibility with other components. Consequently, phase separation occurred, making it difficult to produce flame-retardant polyurethane foam. Furthermore, Production Example 3-1 presented the following problem: due to the high self-cohesion of the produced compound caused by its excessively strong internal hydrogen bonds, the compound could not be well mixed with the first polyol-based compound and the second polyol-based compound.

[0140] Example 1: Production of polyurethane foam

[0141] As the first polyol-based compound, the compound produced in Production Example 1 was prepared, and as the second polyol-based compound, the compound produced in Production Example 2 was prepared, and as the third polyol-based compound, the compound produced in Production Example 3 was prepared.

[0142] In addition, a mixture of aluminum phosphate (Al) and flame retardant melamine powder (melamine cyanurate; MCA) was prepared as a flame retardant, and carbon black was prepared as a dye. L-626 (Momentive), a polyalkoxy-substituted polydimethylsiloxane, was prepared as a foam stabilizer. LC5615 (Momentive), a nickel-based catalyst, was prepared as a catalyst. H12-MDI (Kumho Mitsui Chemicals) was prepared as an isocyanate-based curing agent.

[0143] After this, 70 parts by weight of the first polyol-based compound, 10 parts by weight of the second polyol-based compound and 20 parts by weight of the third polyol-based compound are mixed together to prepare a polyol mixture. The polyol mixture is placed in a stainless steel mixer equipped with an agitator capable of high-speed stirring at 2,000 rpm and uniformly stirred at room temperature. In addition, based on 100 parts by weight of the polyol mixture, 25 parts by weight of a flame retardant, 2 parts by weight of carbon black and 15 parts by weight of calcium carbonate are added to the polyol mixture and well dispersed. Then, based on 100 parts by weight of the polyol mixture, 2 parts by weight of a foam stabilizer and 2 parts by weight of a catalyst are placed in a mixer. The resulting mixture is stirred at high speed for 1 hour or longer, thereby preparing a uniform composition. At this point, the inflow of water is suppressed as much as possible because it will suppress the carbamate formation reaction.

[0144] The prepared composition, isocyanate-based curing agent, and liquid nitrogen were simultaneously supplied to a high-speed mixing head via a metering pump such that the ratio of the total weight of the prepared composition and isocyanate-based curing agent to the volume of liquid nitrogen was 4:1. At this point, 28 parts by weight of the isocyanate-based curing agent was added based on 100 parts by weight of the polyol mixture, and liquid nitrogen was supplied in accordance with the density and hardness of the polyurethane foam composition to be produced. The three components were uniformly mixed together to produce a polyurethane foam composition.

[0145] Thereafter, a polyester film was coated with the prepared polyurethane foam composition and then cured in a curing reactor at a high temperature ranging from about 120° C. to 150° C., thereby producing a polyurethane foam having a density of 0.2 g / cm 3 And a polyurethane foam sheet with a thickness of 3.0 mm.

[0146] Examples 2 and 3 and Comparative Example 1

[0147] A polyurethane foam sheet was produced in the same manner as in Example 1, except that the amounts of carbon black, calcium carbonate, foam stabilizer, and catalyst used in the preparation of the polyurethane foam composition were controlled as shown in Table 4 below.

[0148] Example 4

[0149] A polyurethane foam sheet was produced in the same manner as in Example 3, except that the polyurethane foam composition was prepared by simultaneously supplying the prepared composition, the isocyanate-based curing agent, and the liquid nitrogen to a high-speed mixing head in a ratio of the total weight of the prepared composition and the isocyanate-based curing agent to the volume of liquid nitrogen of 2:1.

[0150] Suction pressure measurement

[0151] Each polyurethane foam sheet produced in Examples 1 to 4 and Comparative Example 1 was cut and installed in the cylinder of an automated system (LG Chem). A vacuum was then applied to a vacuum cup, and the suction pressure when the polyurethane foam sheet was sucked into the cup was measured. The results of these measurements are shown in Table 4 below.

[0152] [Table 4]

[0153]

[0154] In Table 4 above, the content of each of the flame retardant, carbon black, calcium carbonate, foam stabilizer, catalyst, and isocyanate-based curing agent is in parts by weight based on 100 parts by weight of the polyol mixture. Referring to Table 4 above, it can be confirmed that the polyurethane foam sheet produced using the polyurethane foam composition containing 15 parts by weight or 20 parts by weight of calcium carbonate in each of Examples 1 to 4 was sucked at a high suction pressure, indicating that it had excellent vacuum suction characteristics.

[0155] On the other hand, the polyurethane foam sheet produced using the polyurethane foam composition containing an excessive amount (30 parts by weight) of calcium carbonate in Comparative Example 1 was sucked in at a suction pressure of only 45 kPa, indicating that it may not be properly sucked in during the battery pack assembly process, thereby causing the problem of product defects.

[0156] Therefore, it can be seen that the polyurethane foam composition according to one embodiment of the present invention can provide a polyurethane foam having excellent inhalation characteristics. In particular, it can be seen that the polyurethane foam is inhaled at an inhalation pressure of about 53 kPa or higher and thus has excellent inhalation characteristics.

Claims

1. A polyurethane foam composition comprising: a polyol mixture comprising a first polyol-based compound having a glass transition temperature of −50° C. or lower, a second polyol-based compound having a weight average molecular weight of 5,000 to 30,000 g / mol and including at least three functional groups reactive with an isocyanate group, and a third polyol-based compound having an exothermic capacity of 500 J / g·K or lower; Isocyanate-based curing agents; and filler, wherein the filler is calcium carbonate; wherein the filler is contained in an amount of 15 to 20 parts by weight based on 100 parts by weight of the polyol mixture, wherein the second polyol-based compound is a polymer of a second mixture comprising: a polyether-based polyol, a polyfunctional isocyanate-based compound, and a chain extender comprising at least three functional groups reactive with isocyanate groups, wherein the molar ratio of the polyether-based polyol to the chain extender in the second mixture is 1:0.1 to 1:0.45, wherein the third polyol-based compound is a polyol having an exothermic capacity of 500 J / g·K or less, or a polymer of a third mixture comprising a polyol having an exothermic capacity of 500 J / g·K or less and a polyfunctional isocyanate-based compound, The molar ratio of the polyol having an exothermic capacity of 500 J / g·K or less to the polyfunctional isocyanate-based compound in the third mixture is 1:0.05 to 1:0.

25. 2 . The polyurethane foam composition according to claim 1 , wherein the first polyol-based compound is included in an amount of 60 to 75 parts by weight based on 100 parts by weight of the polyol mixture. 3 . The polyurethane foam composition according to claim 1 , wherein the second polyol-based compound is included in an amount of 5 parts by weight to 20 parts by weight based on 100 parts by weight of the polyol mixture. 4 . The polyurethane foam composition according to claim 1 , wherein the third polyol-based compound is included in an amount of 15 parts by weight to 50 parts by weight based on 100 parts by weight of the polyol mixture. 5 . The polyurethane foam composition according to claim 1 , further comprising an additive comprising at least one of a flame retardant, a catalyst, a cross-linking agent, and a dye. 6 . The polyurethane foam composition according to claim 5 , wherein the flame retardant is included in an amount of 20 to 50 parts by weight based on 100 parts by weight of the polyol mixture. 7 . A polyurethane foam comprising a cured product of the polyurethane foam composition according to claim 1 . The polyurethane foam according to claim 7 , which is sucked at a suction pressure of 50 kPa or more.

9. The polyurethane foam according to claim 7, wherein the density of the polyurethane foam is 0.1 g / cm 3 to 0.5g / cm 3 .

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