Polyurethane foam composition having excellent flame retardancy, polyurethane foam comprising same, and automotive interior material

Abstract

The present invention provides a polyurethane foam composition having excellent flame retardancy, a polyurethane foam comprising the same, and an automobile interior material. Specifically, according to an exemplary embodiment of the present invention, a polyurethane foam composition includes 50 to 70 wt% of a polyol mixture including a polyol, a phosphorus-based flame retardant including a hydroxyl group (-OH) at both terminals, a carbon-based flame retardant, a blowing agent, and an additive, and 30 to 50 wt% of an isocyanate.

Description

Technical Field

[0001] The present invention relates to a polyurethane foam composition having excellent flame retardancy, a polyurethane foam comprising the composition, and an automobile interior material. Background Art

[0002] Automotive interior seats are used to provide a satisfying and comfortable experience for passengers in the vehicle. Soft polyurethane foam applied to seats is a material attached to the seat cover or seat foam pad, which works to reduce body pressure in the area in contact with the passenger's body and helps achieve a soft feel.

[0003] Flexible polyurethane foam is divided into block foam and molded foam according to the manufacturing method. Block foam refers to foam that is used by cutting the free foaming and curing foam into the desired shape without injecting the original liquid into the mold. Since block polyurethane foam is mainly used as an indoor interior material, flame retardancy is one of the property requirements.

[0004] On the other hand, the recent increasing demand for hygiene of automotive materials that come into close contact with passengers has led to a demand for the washability of automotive interior seats.

[0005] However, in the case of conventional flexible polyurethane foams for car seats, their flame retardancy is drastically deteriorated when washing is performed, and thus safety regulations for vehicle fires cannot be satisfied.

[0006] In addition, in the case of existing flexible polyurethane foams used for car seats, their flame retardancy is obtained by physically dispersing liquid halogen-based phosphate esters (a chemical organic flame retardant) in the polyurethane matrix. However, as washing proceeds, the polar phosphate esters are lost, resulting in flame retardancy deteriorating with the number of washing cycles.

[0007] Therefore, due to the above background, there is an increasing demand for research on polyurethane foams having excellent flame retardancy even after washing.

[0008] The information included in this Background section of the invention is only for enhancement of understanding of the general background of the invention and is not to be taken as an admission or any form of suggestion that this information forms the prior art already known to a person skilled in the art. Summary of the invention

[0009] Various aspects of the present invention are directed to providing a polyurethane foam having excellent flame retardancy even after cleaning by preventing the flame retardant component from being lost during cleaning.

[0010] The objects of the present invention are not limited to the above objects. The above and other objects of the present invention will become more apparent from the following description, and will be achieved by the means in the claims and their combinations.

[0011] According to an exemplary embodiment of the present invention, the polyurethane foam composition includes: 50 to 70 wt % of a polyol mixture and 30 to 50 wt % of an isocyanate, wherein the polyol mixture includes a polyol, a phosphorus-based flame retardant including a hydroxyl group (-OH) at both ends, a carbon-based flame retardant, a blowing agent, and an additive.

[0012] Relative to the total weight of the polyol mixture, the polyol mixture may include: 75 to 95 wt % of polyol; 5 to 20 wt % of phosphorus-based flame retardant; 3 to 10 wt % of carbon-based flame retardant; 0.5 to 5 wt % of blowing agent; and 1 to 2 wt % of additives.

[0013] The polyol may include: a first polyol including a first polyether polyol including 2 to 4 hydroxyl groups and 5 to 20 wt % of ethylene oxide (EO) relative to the total weight of the polyether polyol, wherein the weight average molecular weight (Mw) of the polyether polyol is in the range of 2,000 to 4,000 g / mol and the hydroxyl value is in the range of 40 to 60 mg KOH / g; a second polyol including a second polyether polyol having a hydroxyl value in the range of 20 to 40 mg KOH / g and including 10 to 60 wt % of a non-volatile phase; and a third polyol including 5 to 7 hydroxyl groups and a weight average molecular weight (Mw) in the range of 2,000 to 4,000 g / mol.

[0014] The polyol may include: 20 to 60 wt % of a first polyol, 20 to 60 wt % of a second polyol; and 5 to 20 wt % of a third polyol, relative to the total weight of the polyol.

[0015] The phosphorus content of the phosphorus-based flame retardant may be in the range of 10 to 20 wt % relative to the total weight of the phosphorus-based flame retardant.

[0016] The hydroxyl value of the phosphorus-based flame retardant may be in the range of 400 to 500 mg KOH / g.

[0017] The particle size of the carbon-based flame retardant may be 0.177 mm or less.

[0018] The carbon content of the carbon-based flame retardant may be in the range of 90% or more relative to the total weight of the carbon-based flame retardant, and the expansion ratio may be 250% or more.

[0019] The isocyanate may include at least one of toluene diisocyanate (TDI), methylene diphenyl diisocyanate (MDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate (H12MDI), and combinations thereof.

[0020] The additive may include an organosilicon surfactant and a catalyst. In addition, relative to the total weight of the polyol mixture, the additive may include: 0.5 to 1 wt% of an organosilicon surfactant; and 0.1 to 0.5 wt% of a catalyst.

[0021] The catalyst may include at least one selected from triethylenediamine, triethylamine, stannous octoate, and combinations thereof.

[0022] In addition, the polyurethane foam according to the exemplary embodiment of the present invention includes a polyurethane foam composition.

[0023] In addition, the automobile interior material according to the exemplary embodiment of the present invention includes polyurethane foam.

[0024] According to an exemplary embodiment of the present invention, by mixing an appropriate amount of polyol, a phosphorus-based flame retardant containing a hydroxyl group (-OH) at both ends, a carbon-based flame retardant, an isocyanate, a foaming agent, and an additive, the flame retardant component can be prevented from being lost during the cleaning process. Therefore, a polyurethane foam having excellent flame retardancy even after cleaning can be prepared.

[0025] According to the exemplary embodiment of the present invention, by introducing two types of flame retardants having different properties into the basic method of manufacturing polyurethane foam, a washable polyurethane foam having good flame retardancy and heat resistance can be prepared.

[0026] The effects of the present invention are not limited to the above-mentioned effects. It should be understood that the effects of the present invention include all effects that can be inferred from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The evaluation results of the heat aging properties of the polyurethane foams of Examples and Comparative Examples are shown.

[0028] It should be understood that the accompanying drawings are not necessarily drawn to scale, but rather present somewhat simplified representations of various features illustrating the basic principles of the invention. The specific design features of the present invention as included herein (including, for example, specific dimensions, orientations, locations, and shapes) will be determined in part by the specific intended application and use environment.

[0029] In the drawings, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing. DETAILED DESCRIPTION

[0030] Reference will now be made in detail to various embodiments of the present invention, examples of which are shown in the accompanying drawings and described below. Although the present invention will be described in conjunction with exemplary embodiments, it should be understood that this description is not intended to limit the present invention to those exemplary embodiments. On the contrary, the present invention is intended to cover not only the exemplary embodiments of the present invention, but also various alternatives, modifications, equivalents and other embodiments, all of which are included in the spirit and scope of the present invention as defined by the claims.

[0031] Through the following exemplary embodiments and in conjunction with the accompanying drawings, the above-mentioned purpose, other purposes, features and advantages of the present invention will be more easily understood. However, the present invention is not limited to the embodiments described herein and can be implemented in other forms. The embodiments described herein are provided so that the present invention can be thorough and complete, and the spirit of the present invention can be fully conveyed to those skilled in the art.

[0032] In the description of the present invention, the terms "comprise", "include" or "have" should be understood to mean the existence of the described features, regions, integers, steps, operations, elements and / or parts, but do not exclude the existence or addition of one or more other features, regions, integers, steps, operations, elements, parts and / or combinations thereof.

[0033] Unless otherwise stated, all numerals, values ​​and / or expressions used herein indicating the amount of components, reaction conditions, polymer compositions and mixtures should be considered approximate values, including various uncertainties that affect measurement that occur inherently when obtaining these values, and therefore should be understood in all cases as modified by the term "about". In addition, when the specification of the present invention includes a numerical range, unless otherwise stated, the range is continuous and includes all values ​​from the minimum value of the range to its maximum value. In addition, when such a range involves integer values, unless otherwise stated, it includes all integers from the minimum value to the maximum value.

[0034] In the specification of the present invention, when a range is described for a variable, it is understood that the variable includes all values ​​within the range, including the endpoints of the range. For example, a range of 5 to 10 includes values ​​5, 6, 7, 8, 9 and 10, and any subranges, such as 6 to 10, 7 to 10, 6 to 9 and 7 to 9. It should be understood to include any value between reasonable integers within the range, such as 5.5, 6.5, 7.5, 5.5 to 8.5 and 6.5 to 9. In addition, for example, a range of "10% to 30%" includes values ​​such as 10%, 11%, 12%, 13%, and all integers less than or equal to 30%, and any subranges such as 10% to 15%, 12% to 18% and 20% to 30%. It should be understood to include any value between reasonable integers within the range, such as 10.5%, 15.5%, 25.5%.

[0035] The present invention relates to a polyurethane foam composition having excellent flame retardancy.

[0036] According to an exemplary embodiment of the present invention, the polyurethane foam composition includes: 50 to 70 wt% of a polyol mixture and 30 to 50 wt% of an isocyanate, wherein the polyol mixture includes a polyol, a phosphorus-based flame retardant including a hydroxyl group (-OH) at both ends, a carbon-based flame retardant, a blowing agent, and an additive.

[0037] Hereinafter, each component constituting the polyurethane foam composition according to an exemplary embodiment of the present invention will be described in more detail.

[0038] <Polyol Mixture>

[0039] According to an exemplary embodiment of the present invention, the polyurethane foam composition may include 50 to 70 wt % of the polyol mixture relative to the total weight thereof.

[0040] The polyol mixture may include a polyol, a phosphorus-based flame retardant including a hydroxyl group (—OH) at both ends, a carbon-based flame retardant, a foaming agent, and an additive.

[0041] (A) Polyol

[0042] The polyol may be included in an amount of 75 to 95 wt % relative to 100 wt % of the polyol mixture.

[0043] The polyol may include: 20 to 60 wt % of a first polyol; 20 to 60 wt % of a second polyol; and 5 to 20 wt % of a third polyol, relative to the total weight thereof.

[0044] In the present invention, the first polyol is used to control the overall physical properties of the final product. The first polyol may include a first polyether polyol, the first polyether polyol comprising 2 to 4 hydroxyl groups and 5 to 20 wt% of ethylene oxide (EO) relative to the total weight of the polyether polyol, the weight average molecular weight (Mw) of the polyether polyol being in the range of 2,000 to 4,000 g / mol, and the hydroxyl value being in the range of 40 to 60 mg KOH / g.

[0045] In the present invention, the second polyol is used to improve the hardness of the final product, ie, polyurethane foam. The second polyol may have a hydroxyl value in the range of 20 to 40 mg KOH / g and contain 10 to 60 wt% of a non-volatile phase.

[0046] When the amount of the second polyol exceeds 60 wt%, the hardness of the polyurethane foam becomes too high, so passengers may complain of discomfort when sitting on the seat. Therefore, the amount of the second polyol is preferably less than 60 wt% relative to 100 wt% of the polyol mixture.

[0047] In the present invention, the third polyol is used to maximize the elasticity of the final product. The third polyol may be a second polyol comprising a polyether polyol having a hydroxyl value in the range of 20 to 40 mg KOH / g and comprising 10 to 60 wt % of a non-volatile phase, and a weight average molecular weight (Mw) of the third polyol in the range of 2,000 to 4,000 g / mol and comprising 5 to 7 hydroxyl groups.

[0048] (B) Phosphorus flame retardants

[0049] Phosphorus-based flame retardants are reactive substances that react with other polyols, isocyanates and water to form a polyurethane network structure.

[0050] In order to prevent the loss of flame retardants in polyurethane foam after cleaning, the flame retardant must have good flame retardancy when adsorbed or dispersed on the surface of polyurethane, rather than in a form that can be easily washed off.

[0051] On the other hand, the phosphorus-based flame retardant used herein contains hydroxyl groups (—OH) at both terminals, and has a form in which phosphorus is bonded to the middle of a polyol serving as a main foaming material.

[0052] Specifically, the phosphorus-based flame retardant may include two or more functional groups, and have a phosphorus content in the range of 10 to 20 wt % relative to the total weight of the phosphorus-based flame retardant, and a hydroxyl value in the range of 400 to 500 mg KOH / g.

[0053] The phosphorus-based flame retardant may be represented by a structural formula as shown in the following Formula 1. In the present case, n may be a number that determines that the molecular weight falls within an appropriate range.

[0054] [Formula 1]

[0055]

[0056] The phosphorus-based flame retardant may be included in an amount of 5 to 20 wt % relative to 100 wt % of the polyol mixture.

[0057] When the amount of phosphorus flame retardant is less than 5wt%, the flame retardant effect is not significant, which is not suitable. On the contrary, when the amount of phosphorus flame retardant exceeds 20wt%, excessive addition may lead to deterioration of the physical properties of polyurethane foam (such as elasticity, hardness, etc.). In addition, there may be a problem of forming a closed cell structure, resulting in shrinkage.

[0058] On the other hand, in polyurethane foam, existing TCEP-based flame retardants can show excellent performance in flame retardancy and property retention. However, existing TCEP-based flame retardants are dispersed and not chemically bonded to polyurethane, so they have weaknesses in heat resistance. In addition, most of the flame retardant components are lost during the cleaning process, so flame retardancy may not be maintained after cleaning.

[0059] Therefore, in an exemplary embodiment of the present invention, the phosphorus-based flame retardant reacts with other polyols, isocyanate, and water to form a polyurethane network structure, so that the final product polyurethane foam maintains flame retardant properties even after washing.

[0060] Therefore, in an exemplary embodiment of the present invention, a phosphorus (P) compound in the form of hydroxyl groups introduced at both ends is used as a phosphorus-based flame retardant to chemically bond to the polyurethane foam matrix. Therefore, the flame retardant in the polyurethane foam can be prevented from being lost after washing.

[0061] (C) Carbon-based flame retardant

[0062] In the present invention, the carbon-based flame retardant is used to supplement the flame retardant performance of the phosphorus-based flame retardant. Compared with the existing TCEP-based flame retardant, the carbon-based flame retardant has the advantage of being environmentally friendly.

[0063] Among the carbon-based flame retardants, oxidized expanded graphite can be used.

[0064] The carbon-based flame retardant may expand at a predetermined temperature or above to block heat and oxygen. In addition, the carbon-based flame retardant may have a carbon content of 90% or more relative to the total weight of the carbon-based flame retardant, and an expansion rate of 250% or more. The carbon content may be in the range of 90% to 98%, and the expansion rate may be in the range of 250% to 350%.

[0065] Generally, the larger the particle size, the better the flame retardant properties of the carbon-based flame retardant. However, according to an exemplary embodiment of the present invention, a carbon-based flame retardant with a particle size of 0.177 mm or less can be used to obtain flame retardant properties in polyurethane foam. When the particle size of the carbon-based flame retardant exceeds 0.177 mm, the expansion rate may be low, resulting in relatively poor flame retardant properties. Therefore, there may be a situation where an excessive amount of carbon-based flame retardant needs to be added, which is undesirable.

[0066] Therefore, using an excessive amount of raw materials other than the main raw material when the polyurethane foam is foamed may cause shrinkage or degradation of physical properties. Therefore, it is preferred to optimize the degradation of physical properties by adjusting the particle size of the carbon-based flame retardant to 0.177 mm or less.

[0067] The carbon-based flame retardant may be included in an amount of 3 to 10 wt % relative to 100 wt % of the polyol mixture.

[0068] When the amount of the carbon-based flame retardant is less than 3 wt %, the flame retardant effect may not be significant, which is not suitable. On the other hand, when the amount of the carbon-based flame retardant exceeds 10 wt %, the excessive use amount may cause shrinkage and deterioration of physical properties.

[0069] Therefore, carbon-based flame retardants are characterized by rapid expansion during combustion and a physical flame retardant mechanism of forming char and blocking oxygen. For this reason, when used with the above-mentioned phosphorus-based flame retardants, a higher level of flame retardant performance can be achieved through the synergy between physical and chemical flame retardant mechanisms.

[0070] (D) Foaming agent

[0071] As the foaming agent, any known foaming agent commonly used in the field of foam technology may be used within an amount that does not impair the effects of the present invention.

[0072] As the blowing agent, water can be generally used. In addition, at least one selected from dichloromethane, n-butane, isobutane, n-pentane, isopentane, dimethyl ether, acetone, carbon dioxide, etc. can be used. These blowing agents can be appropriately selected and used according to known methods of use and according to the density or other properties required for the foam.

[0073] Therefore, in the exemplary embodiment of the present invention, the amount of the foaming agent is not particularly limited. However, if necessary, the amount of the foaming agent may be in the range of 0.5 to 5 wt % relative to 100 wt % of the polyol mixture.

[0074] (E) Additives

[0075] The additive is a component for providing various functions to the polyurethane foam composition. As the additive, any known additive may be used without particular limitation in an amount within a range that does not impair the effects of the present invention.

[0076] Therefore, in the exemplary embodiment of the present invention, the amount of the additive is not particularly limited. However, if necessary, the amount of the additive may be in the range of 1 to 2 wt % relative to 100 wt % of the polyol mixture.

[0077] Additives may include silicone surfactants and catalysts.

[0078] The organosilicon surfactant is used to prevent the generated cells from agglomerating or being destroyed during the cell formation process inside the polyurethane foam, and to control the formation of the cells to obtain uniform shape and size. The organosilicon surfactant can be selected from one or more types of polysiloxane, silicone oil, derivatives thereof, etc.

[0079] The amount of the silicone surfactant may be 0.5 to 1 wt% relative to 100 wt% of the polyol mixture. In this case, when the amount of the silicone surfactant is too small, there is a problem of uneven foam molding. On the contrary, when the amount of the silicone surfactant is too large, fatal problems such as foam shrinkage and deterioration of flame retardant properties may occur.

[0080] The catalyst is not particularly limited, and any known catalyst commonly used in the field of foam technology may be used. The catalyst is used to promote the reaction between the polyol and the isocyanate compound.

[0081] For example, at least one selected from an amine catalyst (such as triethylenediamine, triethylamine, etc.), an organic tin catalyst (such as stannous octoate), and a combination thereof may be used as the catalyst.

[0082] The content of the catalyst may be 0.1 to 0.5 wt % relative to 100 wt % of the polyol mixture. When the amount of the catalyst is too small, the reaction may be delayed, resulting in a problem of curing failure. On the contrary, when the amount of the catalyst is too large, shrinkage or cracking may occur in the foam.

[0083] <Isocyanate>

[0084] Isocyanate is an essential component added when making polyurethane foam and is used to initiate a chemical reaction with a polyol mixture. Isocyanate can make the hard and soft segments in the polyurethane structure evenly distributed through the chemical reaction of polyols.

[0085] According to an exemplary embodiment of the present invention, the content of the isocyanate may be 30 to 50 wt % with respect to the total weight of the polyurethane foam composition.

[0086] As isocyanate, any known isocyanate can be used, without particular limitation, in an amount that does not impair the effects of the present invention. For example, the isocyanate may include at least one selected from toluene diisocyanate (TDI), methylene diphenyl diisocyanate (MDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate (H12MDI), and combinations thereof. Preferably, toluene diisocyanate can be used as the isocyanate.

[0087] From another perspective, the present invention relates to a polyurethane foam. According to an exemplary embodiment of the present invention, the polyurethane foam comprises the polyurethane foam composition.

[0088] From a further perspective, the present invention relates to an automotive interior material. According to an exemplary embodiment of the present invention, the automotive interior material comprises the polyurethane foam described above.

[0089] Therefore, according to the exemplary embodiment of the present invention, the polyurethane foam may be used in a wide range of applications, not only in the automotive field.

[0090] Therefore, according to the exemplary embodiment of the present invention, the polyurethane foam may be effectively used as a car seat foam requiring excellent flame retardancy even after washing.

[0091] In addition, the present invention can be applied to a washable seat cover by combining with a fabric or leather material, which can maintain the combustibility after washing.

[0092] In addition, in the exemplary embodiment of the present invention, the heat resistance is better than that of the existing soft polyurethane foam for automobile seats. Therefore, when applied to a heated seat with a heater or a steering wheel, it may have the effect of improving long-term durability.

[0093] Hereinafter, the present invention will be described in more detail with reference to specific embodiments. The following embodiments are only examples to help understand the present invention, and the protection scope of the present invention is not limited thereto.

[0094] Example

[0095] The components and contents of the polyols used in the examples are shown in Table 1 below. In addition, the components and contents of the polyol mixtures containing the corresponding polyols are shown in Table 2 below.

[0096] A polyol mixture was prepared using the components and contents according to the following Table 2. Each polyol mixture was mixed with an isocyanate at a weight ratio of 62:38 to prepare a composition for manufacturing a polyurethane foam. In this case, toluene diisocyanate (TDI) was used as the isocyanate.

[0097] [Table 1]

[0098]

[0099] [Table 2]

[0100]

[0101]

[0102] Next, each composition was foamed as follows to prepare a polyurethane foam sample for a seat.

[0103] Specifically, after mixing the components, each polyurethane foam sample was stirred at about 2,000 rpm for about 10 seconds, injected into a wooden mold, aged after generating carbon dioxide, and stored for 1 day in a place where the temperature and humidity were kept constant. Then, the physical properties thereof were measured according to the physical property standard MS200-34 for polyurethane foam. Specifically, the apparent density related to the weight and physical properties of the foam was set to 32±3 kg / m with respect to the core density measured for the sample cut from the mat. 3 In addition, the physical properties are measured under the conditions that the basic performance required for the seat component unit is satisfied.

[0104] The physical properties of each polyurethane foam sample manufactured in the same manner as described above were confirmed by the following methods.

[0105] Experimental Example 1 - Changes in physical properties before and after cleaning

[0106] First, in order to confirm the difference in the change of physical properties of the polyurethane foams before and after cleaning according to the examples and comparative examples, the burning rate, density and hardness of the samples before and after cleaning were measured by the evaluation method of the following items for the samples prepared according to the compositions of the examples and comparative examples. The results are shown in the following Table 4.

[0107] [Evaluation method]

[0108] (1) Hardness (kPa): According to KS M ISO 6672, the hardness of the sample was measured using a hardness measuring device (UTM) at room temperature (25° C.).

[0109] Specifically, each sample with a size of 300×300 and a thickness of 50 mm was fixed in a fixing fixture. Then, a load was applied to the pressure plate at a speed of 50 mm / min so that the sample was compressed to a quarter of the original thickness. When 20 seconds passed, the pressure value (kPa) was measured.

[0110] (2) Apparent density: After measuring the weight and volume of a test sample according to KS M ISO 6672, the apparent density was calculated according to Formula 1. However, the result is expressed as an average value of three samples.

[0111] [Formula 1]

[0112] A=W / V

[0113] Here, A represents the apparent density (g / cm 3 ), V represents volume (cm 3 ), and W represents weight (g).

[0114] (3) Combustibility: Only samples that meet the flammability requirements before cleaning are tested for flammability after cleaning. In the flammability test, the burning rate is measured according to the MS300-08 standard established by Hyundai Motor Company. Here, SE stands for self-extinguishing.

[0115] (4) Cleaning method: The cleaning method was performed up to 5 times according to KS K ISO 6330 (Textiles - Home washing and drying procedures for textile testing). Specific cleaning conditions are shown in Table 3 below.

[0116] [Table 3]

[0117]

[0118] [Table 4]

[0119]

[0120]

[0121] First, in Comparative Example 1, a TCEP-based flame retardant used in conventional automotive seat foam was used.

[0122] Referring to the results in Table 4, the burning rate of Comparative Example 1 using a TCEP-based flame retardant before cleaning meets the standard material requirements established by Hyundai Motor Company and domestic / international safety regulations. However, in Comparative Example 1, the burning rate increases as cleaning proceeds. As a result, when cleaning is performed three or more times, the burning rate appears to no longer meet the regulations and standard material requirements.

[0123] This is because the liquid flame retardant having a low molecular weight is physically dispersed in the polyurethane matrix due to the properties of the TCEP-based flame retardant used in Comparative Example 1. Therefore, the amount of the flame retardant in the polyurethane decreases as the washing proceeds.

[0124] In addition, comparative examples 2 to 4 were prepared by using only phosphorus-based flame retardants instead of TCEP-based flame retardants, and their densities were 32±3 kg / m 3 range, and the hardness is within 16±2kgf / 314cm 2 The range is comparable to that of Comparative Example 1 of the prior art.

[0125] Therefore, when the phosphorus-based flame retardant is used alone, the burning rate shows a level comparable to that of Comparative Example 1 only when the addition amount of the flame retardant is 16 wt % or more relative to 100 wt % of the polyol mixture, as in Comparative Example 4.

[0126] On the other hand, in Comparative Example 4, it can be seen that when washing was performed three times or more, the flame retardant property after washing was deteriorated.

[0127] Furthermore, Comparative Examples 5 to 7 were prepared by using only the carbon-based flame retardant instead of the TCEP-based flame retardant, and they achieved a level comparable to that of Comparative Example 1 of the prior art.

[0128] Therefore, when the carbon-based flame retardant is used alone, the density is slightly reduced when the addition amount of the flame retardant is 4.5 wt% or more relative to 100 wt% of the polyol mixture. In addition, it can be seen that the higher the amount of the carbon-based flame retardant, the lower the hardness.

[0129] This appears to be because the carbon-based flame retardant binds to the isocyanate rather than the polyol, preventing the formation of urethane bonds that enable hardness.

[0130] Furthermore, it can be seen that in Comparative Examples 4 to 7, when washing was performed three times or more, the flame retardant property after washing was deteriorated.

[0131] On the other hand, in Examples 1 to 4 in which appropriate amounts of carbon-based flame retardants and phosphorus-based flame retardants were added, the combustion rate did not increase even after cleaning, confirming that the flame retardant properties were maintained even after cleaning. It can be seen that the flame retardant properties were greatly improved when the two flame retardants were used, due to the synergistic effect of the flame retardant mechanism of free radical scavenging and char formation of the two flame retardants, compared with the use of any one flame retardant.

[0132] Experimental Example 2 - Thermal Aging Evaluation

[0133] Next, in order to confirm the thermal aging properties of the samples manufactured using the compositions according to the examples and comparative examples, the samples manufactured using the compositions according to the examples and comparative examples were evaluated according to the evaluation methods of the following items. The results are shown in Table 5 and Table 6. Figure 1 shown.

[0134] [Evaluation method]

[0135] (1) Hardness and density: measured in the same manner as in the physical properties.

[0136] (2) Permanent shrinkage: The thickness of each sample with a size of 50×50 mm and a thickness ranging from 20 to 50 mm was measured at the center. Next, the sample was compressed and fixed to 70% of the original thickness using parallel compression plates. The sample was then kept at the measurement temperature for 22 hours. Subsequently, the sample was left at room temperature for 30 minutes, and the thickness of the sample at the same position was measured. Finally, the permanent shrinkage was calculated according to the following formula 2.

[0137] [Formula 2]

[0138] CS=[(T0 -T 1 ) / T 0 ]×100

[0139] Here, CS represents compression set (%), T 0 represents the initial thickness of the test sample (mm), and T 1 Represents the thickness of the test sample after testing (mm).

[0140] (3) Heat aging properties: The test specimen for measuring hardness was aged in a constant temperature bath maintained at 80°C for 22 hours and left at room temperature for 1 hour. Then, the hardness was measured and the hardness change rate was obtained according to the following formula 3. However, the results are expressed as the average of three specimens.

[0141] [Formula 3]

[0142] DS=[(SS 0 ) / S 0 ]×100

[0143] Here, DS represents the hardness change rate (%), S 0 represents the average value (kgf) of the hardness before heating, and S represents the average value (kgf) of the hardness after heating.

[0144] [Table 5]

[0145]

[0146] Figure 1 Evaluation results of heat aging properties of polyurethane foams according to Examples and Comparative Examples are shown.

[0147] See Table 5 and Figure 1 When left at 140° C. for 168 hours, it can be seen that the prior art comparative example 1 was broken due to the generation of a large amount of smoke. In addition, it can be considered that the comparative example 1 was actually carbonized because its elongation and hardness decreased rapidly.

[0148] On the other hand, in Example 1 according to the exemplary embodiment of the present invention, the polyurethane foam generates less smoke, and thus carbonization occurs less. As a result, the elongation and hardness decrease by less than 20% compared to before heat aging.

[0149] Therefore, it can be seen that Example 1 also satisfies the values ​​generally specified in the material requirements established by HKMC. Therefore, the polyurethane foam according to the exemplary embodiment of the present invention has high durability even during the accelerated aging test and has a longer service life than the existing foam even under high temperature conditions.

[0150] For ease of interpretation and accurate definition in the claims, the terms "upper", "lower", "inner", "outer", "up", "lower", "upward", "downward", "front", "rear", "back", "inside", "outside", "inward", "outward", "interior", "exterior", "inner", "exterior", "forward" and "rearward" are used to describe the features of the exemplary embodiments with reference to the positions of such features shown in the figures. It should also be understood that the term "connect" or its derivatives refer to both direct and indirect connections.

[0151] The term "and / or" may include a combination of a plurality of related listed items or any one of a plurality of related listed items. For example, "A and / or B" includes all three situations such as "A", "B" and "A and B".

[0152] In this specification, unless particularly stated otherwise, a singular expression includes a plural expression unless the context clearly states otherwise.

[0153] In an exemplary embodiment of the present invention, “at least one of A and B” may refer to “at least one of A or B” or “at least one of a combination of one or more of A and B”. Furthermore, “one or more of A and B” may refer to “one or more of A or B” or “one or more of a combination of one or more of A and B”.

[0154] In exemplary embodiments of the present invention, it should be understood that terms such as "including" or "having" are intended to specify the presence of features, numbers, steps, operations, elements, parts, or combinations thereof described in this specification, but do not exclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, elements, parts, or combinations thereof.

[0155] The foregoing descriptions of specific exemplary embodiments of the present invention are given for purposes of illustration and description. These descriptions are not intended to be exhaustive or to limit the invention to the precise form disclosed, and it is apparent that many modifications and variations are possible in light of the above teachings. The exemplary embodiments are selected and described in order to explain certain principles of the present invention and their practical applications, so that other persons skilled in the art can make and utilize various exemplary embodiments of the present invention and various alternatives and modifications thereof. The scope of the present invention is intended to be defined by the claims and their equivalents.

Claims

1. A polyurethane foam composition comprising: 50 to 70 wt% of a polyol mixture, and 30 to 50 wt% of isocyanate, The polyol mixture comprises: Polyols, A phosphorus-based flame retardant containing hydroxyl groups at both ends, Carbon flame retardant, Blowing agents, and additive.

2. The polyurethane foam composition according to claim 1, wherein the polyol mixture comprises, relative to the total weight of the polyol mixture: 75 to 95 wt% polyol; 5 to 20 wt% of a phosphorus-based flame retardant; 3 to 10 wt% of a carbon-based flame retardant; 0.5 to 5 wt% of a blowing agent; and 1 to 2 wt% of additives.

3. The polyurethane foam composition of claim 1, wherein the polyol comprises: A first polyol comprising a first polyether polyol comprising 2 to 4 hydroxyl groups and 5 to 20 wt % of ethylene oxide EO relative to the total weight of the polyether polyol, wherein the weight average molecular weight Mw of the polyether polyol is in the range of 2,000 to 4,000 g / mol and the hydroxyl value is in the range of 40 to 60 mg KOH / g; A second polyol comprising a second polyether polyol having a hydroxyl value in the range of 20 to 40 mg KOH / g and comprising 10 to 60 wt % of a non-volatile phase; and A third polyol includes 5 to 7 hydroxyl groups and has a weight average molecular weight Mw in the range of 2,000 to 4,000 g / mol.

4. The polyurethane foam composition according to claim 3, wherein the polyol comprises, relative to the total weight of the polyol: 20 to 60 wt % of a first polyol; 20 to 60 wt % of a second polyol; and 5 to 20 wt% of a third polyol. 5 . The polyurethane foam composition according to claim 1 , wherein the phosphorus content of the phosphorus-based flame retardant is in the range of 10 to 20 wt % relative to the total weight of the phosphorus-based flame retardant. 6 . The polyurethane foam composition according to claim 1 , wherein the phosphorus-based flame retardant has a hydroxyl value in the range of 400 to 500 mg KOH / g. 7 . The polyurethane foam composition according to claim 1 , wherein the carbon-based flame retardant has a particle size of 0.177 mm or less. 8 . The polyurethane foam composition according to claim 1 , wherein the carbon content of the carbon-based flame retardant is 90% or more, and the expansion rate is 250% or more, relative to the total weight of the carbon-based flame retardant.

9. The polyurethane foam composition according to claim 1, wherein the isocyanate comprises at least one selected from the group consisting of toluene diisocyanate, methylene diphenyl diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and combinations thereof.

10. The polyurethane foam composition according to claim 1, wherein the additive comprises a silicone surfactant and a catalyst, and in, Relative to the total weight of the polyol mixture, the additive comprises: 0.5 to 1 wt% of a silicone surfactant; and 0.1 to 0.5 wt% catalyst.

11. The polyurethane foam composition according to claim 10, wherein the catalyst comprises at least one selected from the group consisting of triethylenediamine, triethylamine, stannous octoate, and combinations thereof. 12 . A polyurethane foam comprising the polyurethane foam composition according to claim 1 .

13. An automobile interior material comprising the polyurethane foam according to claim 12.

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