Method for manufacturing non-isocyanate polyurethane foam and non-isocyanate polyurethane foam manufactured thereby

Abstract

The present invention relates to a method for manufacturing a non-isocyanate polyurethane (NIPU) foam and a non-isocyanate polyurethane-containing foam manufactured thereby and, more specifically, to a method for manufacturing a non-isocyanate polyurethane foam capable of replacing conventional isocyanate polyurethane due to its excellent thermal properties and elastic restoring force, and to a non-isocyanate polyurethane-containing foam manufactured thereby.

Description

Method for manufacturing non-isocyanate polyurethane foam and non-isocyanate polyurethane foam manufactured thereby

[0001] The present invention claims the benefit of the filing date of Korean Patent Application No. 10-2025-0013063 filed with the Korean Intellectual Property Office on February 3, 2025, and the entire contents thereof are incorporated into the present invention.

[0002] The present invention relates to a method for manufacturing non-isocyanate polyurethane foam and a non-isocyanate foam manufactured thereby. More specifically, it relates to a method for manufacturing non-isocyanate polyurethane foam (NIPU) that can replace conventional isocyanate polyurethane due to its excellent thermal properties and elastic recovery strength, and to the non-isocyanate polyurethane foam manufactured thereby.

[0003] Polyurethane exhibits acid, alkali, oil, and abrasion resistance, as well as low-temperature properties and shock absorption due to its excellent tensile strength and elasticity. Furthermore, it is characterized by being relatively inexpensive and easy to install, making it primarily used in facilities closely related to daily life, such as elastic paving materials for sports facilities like jogging or cycling paths, children's playgrounds, and athletic tracks, as well as polyurethane waterproofing materials and polyurethane flooring materials.

[0004] However, polyurethane, which is applied in such diverse fields, has been the subject of controversy regarding its harmfulness to the human body as four major hazardous heavy metals—lead, chromium, mercury, and cadmium—were detected at levels tens of times higher than the standard limits.

[0005] Here, polyurethane is manufactured by forming urethane bonds through the chemical bonding of alcohol groups and isocyanate groups via the reaction of an alcohol group (-OH) containing compound and an isocyanate group (-NCO) containing compound, and then curing the resulting product. Compositions for manufacturing such polyurethane are broadly classified into one-component and two-component types. Among these, the two-component polyurethane composition consists of a main component (prepolymer part) and a curing agent. The main component and the curing agent are manufactured separately and then mixed at the stage of use.

[0006] Conventional phthalate-based plasticizers have been used in such polyurethane compositions, but phthalate-based plasticizers are classified as suspected endocrine disruptors and have been banned from use in various fields both domestically and internationally.

[0007] In addition, MOCA (4,4'-Methylenebis(2-chloroaniline)) has been primarily used as a chain extender (curing agent) in polyurethane compositions to improve mechanical properties such as tensile strength, hardness, and tensile strength. However, MOCA has been designated as a hazardous chemical substance as a carcinogen, and mixtures containing more than 0.1% of MOCA are also designated as hazardous chemicals, which creates many restrictions on its use in manufacturing and construction sites.

[0008] Therefore, in order to address the aforementioned problems, the inventors recognized the urgent need to develop a method for manufacturing non-isocyanate polyurethane having excellent elastic recovery power to solve various environmental problems arising from conventional isocyanate-based polyurethanes, and thus completed the present invention.

[0009] The problem that the present invention aims to solve is to provide a method for manufacturing a non-isocyanate polyurethane foam (NIPU) that has excellent thermal properties and elastic recovery power and allows for stiffness control.

[0010] The problem that the present invention aims to solve is to provide a non-isocyanate polyurethane foam manufactured by the above-described manufacturing method.

[0011] The technical problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art to which the present invention belongs from the description below.

[0012] To achieve the above objective, according to one aspect of the present invention, a method for manufacturing a non-isocyanate polyurethane (NIPU) foam is provided, comprising: a step of reacting a compound represented by the following chemical formula 3 and a compound represented by the following chemical formula 4 to produce a compound represented by the following chemical formula 2; and a step of reacting the compound represented by the following chemical formula 2 and a compound represented by the following chemical formula 5 to produce a compound represented by the following chemical formula 1.

[0013] [Chemical Formula 1]

[0014]

[0015] [Chemical Formula 2]

[0016]

[0017] [Chemical Formula 3]

[0018]

[0019] [Chemical Formula 4]

[0020]

[0021] [Chemical Formula 5]

[0022]

[0023] In the above chemical formulas 1 to 5, R1 is -(C=O)-(C1-C6alkylene)-S-(CH2)- or -(C=O)-(C1-C6alkylene)-SO2-(CH2)-, and R2 is -(C1-C4alkylene)-O-[R1-CH(CH3OH)-O-(C=O)-NH-R3-NH-(C=O)-O-CH2-CH(OH)-R1] n - or -(C1-C6-alkyl), and R3 is -(C1-C 12 R4 is -(C1-C6alkylene)- or -(C1-C6alkylene)-aryl-(C1-C6alkylene)-, R5 is -(C=O)-(C1-C6alkylene)-S-(C3O3H3), R5 is -(C=O)-(C1-C6alkylene)-SH or -(C=O)-(C1-C6alkylene)-SO2H, and R6 is -(C1-C 4- It is alkylene)-(O)-R5 or -(C1-C6-alkyl), where X is -I, -Br, -Cl or -OH, and n is an integer from 1 to 10.

[0024] According to another aspect of the present invention, a NIPU foam manufactured according to the above manufacturing method is provided.

[0025] A method for manufacturing a non-isocyanate polyurethane (NIPU) foam according to one embodiment of the present invention and a NIPU foam manufactured thereby have an open cell structure, thereby controlling the cell size more easily by controlling the network formation of NIPU polymers, which can be applied to various cushioning materials.

[0026] In addition, the method for manufacturing a non-isocyanate polyurethane (NIPU) foam according to one embodiment of the present invention and the NIPU foam manufactured thereby possess excellent thermal stability and elastic recovery power, and allow for stiffness control, so they can replace commercially available isocyanate-based polyurethane (PU) in various cushioning fields.

[0027] The effects of the present invention are not limited to those described above, and unmentioned effects will be clearly understood by those skilled in the art from the present specification and the accompanying drawings.

[0028] Figure 1 is the IR spectrum of (a) before the reaction and (b) after the reaction of a compound represented by Formula 1a prepared in Example 1 according to the present invention.

[0029] Figure 2 is the IR spectrum of (a) before the reaction and (b) after the reaction of the compound represented by Formula 2a prepared in Example 2 according to the present invention.

[0030] Figure 3 is the IR spectrum of a compound represented by Formula 1c prepared in Example 3 according to the present invention.

[0031] Figure 4 is the IR spectrum of a compound mixed with formulas 1a and 1c prepared in Example 4 according to the present invention.

[0032] FIG. 5 is a scanning electron microscopy (SEM) image of non-isocyanate polyurethane (NIPU) foams 1a to 1c prepared in Example 1 according to the present invention.

[0033] Figure 6 is a scanning electron microscopy (SEM) image of NIPU 2a to 2c foams prepared in Example 2 according to the present invention.

[0034] FIG. 7 is a Differential Scanning Calorimetry (DSC) curve of NIPU 1a to 1c forms prepared in Example 1 according to the present invention.

[0035] FIG. 8 is a Differential Scanning Calorimetry (DSC) curve of NIPU 2a to 2c forms prepared in Example 2 according to the present invention.

[0036] FIG. 9 is a thermogravimetric analysis (thermal gravimetric analysis, TGA) curve of NIPU 1a to 1c foams prepared in Example 1 according to the present invention.

[0037] FIG. 10 is a thermogravimetric analysis (thermal gravimetric analysis, TGA) curve of NIPU 2a to 2c foams prepared in Example 2 according to the present invention.

[0038] Figure 11 is a graph of repeated compressive stress for NIPU 1a foam and NIPU 2a foam prepared in Examples 1 and 2 to verify the compressive performance of the NIPU foam according to the present invention.

[0039] FIG. 12 is a graph of repeated compressive stress for NIPU 4a foam to NIPU 4d foam manufactured in Example 4 to verify the compressive performance of the NIPU foam according to the present invention.

[0040] FIG. 13 is a graph of the compressive stress of NIPU foams 1a to 1c prepared in Example 1 according to the present invention.

[0041] FIG. 14 is a graph of the compressive elasticity modulus of NIPU foams 1a to 1c manufactured in Example 1 according to the present invention and a conventional foam.

[0042] FIG. 15 is a graph of the compressive elasticity modulus of NIPU foams 4a to 4d prepared in Example 4 according to the present invention and a conventional foam.

[0043] Specific details for implementing the present invention will be described in detail below with reference to the attached drawings.

[0044] When a part of the entire specification is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0045] Throughout the entire specification, when it is said that a component is located "on" another component, this includes not only cases where a component is in contact with another component, but also cases where another component exists between the two components.

[0046] Throughout the present specification, terms including ordinal numbers, such as “first” and “second,” are used for the purpose of distinguishing one component from another and are not limited by said ordinal numbers.

[0047] In describing the principles of a preferred embodiment of the present invention in detail, if it is determined that a specific description of related known functions or configurations could unnecessarily obscure the essence of the present invention, such detailed description is omitted.

[0048] Method for manufacturing non-isocyanate polyurethane (NIPU) foam

[0049] According to one aspect of the present invention, a method for manufacturing a non-isocyanate polyurethane (NIPU) foam is provided, comprising: a step of producing a compound represented by the following chemical formula 2 by reacting a compound represented by the following chemical formula 3 and a compound represented by the following chemical formula 4; and a step of producing a compound represented by the following chemical formula 1 by reacting the compound represented by the following chemical formula 2 and a compound represented by the following chemical formula 5.

[0050] [Chemical Formula 1]

[0051]

[0052] [Chemical Formula 2]

[0053]

[0054] [Chemical Formula 3]

[0055]

[0056] [Chemical Formula 4]

[0057]

[0058] [Chemical Formula 5]

[0059]

[0060] In the above chemical formulas 1 to 5, R1 is -(C=O)-(C1-C6alkylene)-S-(CH2)- or -(C=O)-(C1-C6alkylene)-SO2-(CH2)-, and R2 is -(C1-C4alkylene)-O-[R1-CH(CH3OH)-O-(C=O)-NH-R3-NH-(C=O)-O-CH2-CH(OH)-R1] n - or -(C1-C6-alkyl), and R3 is -(C1-C 12R4 is -(C1-C6alkylene)- or -(C1-C6alkylene)-aryl-(C1-C6alkylene)-, R5 is -(C=O)-(C1-C6alkylene)-S-(C3O3H3), R5 is -(C=O)-(C1-C6alkylene)-SH or -(C=O)-(C1-C6alkylene)-SO2H, and R6 is -(C1-C 4- It is alkylene)-(O)-R5 or -(C1-C6-alkyl), where X is -I, -Br, -Cl or -OH, and n is an integer from 1 to 10.

[0061] According to one embodiment of the present invention, in the formulas 1 to 5, R1 is -(C=O)-(C1-C4alkylene)-S-(CH2)- or -(C=O)-(C1-C6alkylene)-SO2-(CH2)-, and R2 is -(C1-C4alkylene)-O-[R1-CH(CH3OH)-O-(C=O)-NH-R3-NH-(C=O)-O-CH2-CH(OH)-R1] n - or -(C1-C4-alkyl), R3 is -(C1-C8alkylene)- or -(C1-C4alkylene)-aryl-(C1-C4alkylene)-, R4 is -(C1-C4-alkyl) or -(C1-C4alkylene)-O-(C=O)-(C1-C4alkylene)-S-(C3O3H3), R5 is -(C=O)-(C1-C4alkylene)-SH, and R6 is -(C1-C 4- It is alkylene)-(O)-R5 or -(C1-C6-alkyl), where X is -Br or -Cl, and n is an integer from 1 to 10.

[0062] Hereinafter, a method for manufacturing the above-mentioned non-isocyanate polyurethane (NIPU) foam will be explained in more detail.

[0063] First, the present invention provides a step of preparing a compound represented by Chemical Formula 2 by reacting a compound represented by Chemical Formula 3 and a compound represented by Chemical Formula 4.

[0064] The reaction for preparing the compound represented by the above chemical formula 2 is, for example, as shown in the following reaction formula 1.

[0065] [Reaction Equation 1]

[0066]

[0067] In the above reaction equation 1, R1, R4, R5, R6, and X are as defined above.

[0068] As shown in reaction scheme 1 above, the compound represented by chemical formula 3 and the compound represented by chemical formula 4 can be prepared by combining the two compounds as -H is removed from the -SH of X of the compound represented by chemical formula 3 and R5 of the compound represented by chemical formula 4.

[0069] More specifically, according to one embodiment of the present invention, the step of preparing a compound represented by Formula 2 comprises: mixing a compound represented by Formula 3 and a compound represented by Formula 4; and reacting the mixture in the presence of an alkaline metal compound.

[0070] The compound represented by the above chemical formula 3 is, for example, , , or It may be, preferably , or It can be, and more preferably or It can be, and more preferably It could be.

[0071] When using the compound represented by the above chemical formula 3, the framework of the compound represented by the chemical formula 1 of the present invention can be formed through a ring-opening reaction and a polymerization reaction with the amine compound represented by the chemical formula 5 described later.

[0072] The method for preparing the compound of Chemical Formula 3 above is not particularly limited, but glycerol, which is a biomass-based sugar alcohol ( It can be manufactured using ) and CO2 as source materials.

[0073] For example, a compound represented by the above chemical formula 3 In order to manufacture, the above glycerol is reacted with hydrogen bromide (hydrobromionic acid, HBr) to produce 1,3-dibromo-2-propanol (1,3-Dibromo-2-propanol, ) can be manufactured. At this time, NaHCO-3 is obtained based on a carbon dioxide (CO2) source, and the 1,3-dibromo-2-propanol is reacted with NaHCO-3 to obtain an example of a compound represented by Chemical Formula 3. It can be manufactured as follows. At this time, it can be manufactured by appropriately changing the hydrogen bromide reacting with the glycerol and appropriately changing the structure of the compound represented by Chemical Formula 3.

[0074] The compound represented by the above chemical formula 4 is, for example, , , , or It may be, preferably , , or It can be, and more preferably , or It can be, and more preferably or It could be.

[0075] When using the above compound, it is possible to form the central framework of the compound represented by Chemical Formula 1 and to manufacture a flexible NIPU rather than a rigid NIPU through the long alkyl chain.

[0076] The compound represented by Chemical Formula 3 and the compound represented by Chemical Formula 4 can be mixed in a molar ratio of 1 to 10:1, preferably 1 to 8:1, more preferably 1 to 6:1, even more preferably 2 to 5:1, and most preferably 2 to 4:1.

[0077] In addition, a mixture of the compound represented by the above chemical formula 3 and the compound represented by the above chemical formula 4 can be reacted in the presence of a base.

[0078] According to one embodiment of the present invention, the base may be an alkaline metal compound, a nitrogen-containing compound, or a mixture thereof. The alkaline metal compound may be one or more selected from the group consisting of K(OH), K2CO3, NaCO3, LiCO3, MgCO3, Ca(OH)2, and CaCO3, and the nitrogen-containing compound It may be one or more selected from the group consisting of and (NH4)3CO3.

[0079] The above base can play a role in increasing the reactivity between the -SH group of the compound represented by Chemical Formula 4 and the -X of the compound represented by Chemical Formula 3 in the above reaction.

[0080] The above reaction may be carried out in a first solvent. The first solvent is a solvent capable of dissolving the compound represented by Formula 3 and the compound represented by Formula 4, and may be an alcohol having 1 to 4 carbon atoms, acetone, diethyl ether, dichloromethane (DCM), dimethyl sulfoxide (DMSO), dimethylformamide (DMF), dimethylacetamide (DMA), ethyl acetate, dimethylmethanol, or a mixture thereof.

[0081] The compound represented by Chemical Formula 2, prepared according to the above manufacturing method, can be produced with a high yield of 90% or more.

[0082] According to one embodiment of the present invention, the compound of Formula 2 is , , , , , , , , or It can be, preferably , , , , , , or It can be, and more preferably , , or It could be.

[0083] Next, the present invention provides the step of preparing a compound represented by the following chemical formula 1 by reacting the compound represented by the above chemical formula 2 and the compound represented by the following chemical formula 5.

[0084] The reaction for preparing the compound represented by the above chemical formula 1 is, for example, as shown in reaction formula 2 below.

[0085] [Reaction Equation 2]

[0086]

[0087] In the above reaction equation 2, R1, R2, R3, R4, and n are as defined above.

[0088] As shown in reaction scheme 2 above, the cyclic carbonate group of the compound represented by chemical formula 2 is opened (open reaction) by a catalyst (or base), and polymerized with the compound represented by chemical formula 5 to produce a compound having the structure of a non-isocyanate polyurethane (NIPU) represented by chemical formula 1.

[0089] More specifically, according to one embodiment of the present invention, the method comprises the steps of: adding a catalyst to a compound represented by Formula 2; and reacting the catalyst mixture with a compound represented by Formula 5.

[0090] The above catalyst is a substance added to open the cyclic carbonate of the compound represented by Chemical Formula 2, and can promote the reaction between the cyclic carbonate rings.

[0091] The above catalysts are 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5-Diazabicyclo[4.3.0]non-5-ene (DBN), and 1,4-diazabicyclo[2.2.2]octane (DABCO). It may be one or more selected from the group consisting of K2CO3, Na2CO3, CaCO3, Li2CO3, (NH4)2CO3, MgCO3, KOH, and NaOH.

[0092] When a catalyst is added to the compound represented by the above chemical formula 2, a nucleating agent additive and a foaming agent may be further added.

[0093] The above nucleating agent additive may be hydrotalcite.

[0094] The above nucleating agent additive can be added to form the cell size of the compound represented by Chemical Formula 1, i.e., NIPU foam.

[0095] The above foaming agent may be an aqueous solvent or a compound having an -SH(thiol) group.

[0096] The above aqueous solvent may be water (H2O), and the compound having the -SH group is

[0097]

[0098]

[0099] It may be one or more types selected from the group formed.

[0100] When a water-based solvent is used as the foaming agent, it is environmentally friendly and applicable to mass production compared to using conventional organic compounds as foaming agents.

[0101] After adding the catalyst, the step of homogenizing the catalyst mixture may be further included.

[0102] The above homogenization is a process of mixing the compound represented by Chemical Formula 2 and the catalyst (or base) so that they are evenly mixed, and can be performed by stirring at a speed of 1,000 to 3,000 rpm for 0.5 to 10 minutes.

[0103] In addition, the compound represented by Chemical Formula 2 and the compound represented by Chemical Formula 5 can be mixed in a molar ratio of 1 to 10:1, preferably 1 to 8:1, more preferably 1 to 6:1, even more preferably 2 to 5:1, and most preferably 2 to 4:1.

[0104] In addition, the step of reacting the catalyst mixture with the compound represented by Formula 5 can be carried out at 80 to 120°C for 0.5 to 12 hours, preferably for 0.5 to 6 hours, more preferably for 1 to 6 hours, even more preferably for 2 to 6 hours, and most preferably for 2 to 4 hours.

[0105] Through the above reaction, the compound represented by Chemical Formula 2, in which the cyclic carbonate is open, and the amine compound represented by Chemical Formula 5 can be polymerized to produce the compound represented by Chemical Formula 1 according to the present invention.

[0106] The non-isocyanate polyurethane (NIPU) foam represented by Chemical Formula 1, manufactured according to the above manufacturing method, can replace conventional isocyanate polyurethane in various applications due to its excellent thermal properties and elastic recovery.

[0107] According to one embodiment of the present invention, after the step of preparing the compound represented by Formula 1, the step of reacting the compound represented by Formula 1 with an oxidizing agent may be further included.

[0108] According to one embodiment of the present invention, the oxidizing agent may include one or more selected from the group consisting of potassium peroxymonosulfate (KHSO5), m-chloroperoxybenzoic acid (m-CPBA), hydrogen peroxide (H2O2), 2-iodoxybenzoic acid (IBX), and potassium persulfate (K2S2O8). At this time, a sulfonyl group may be added to the compound represented by Formula 1 by reacting the compound represented by Formula 1 with the oxidizing agent, and the stiffness of the non-isocyanate polyurethane compound represented by Formula 1 may be controlled by the sulfonyl group.

[0109] According to one embodiment of the present invention, the oxidizing agent can be dissolved in a second solvent and react with a compound represented by the chemical formula 1.

[0110] According to one embodiment of the present invention, the second solvent is a mixture of water and an organic solvent, wherein the organic solvent may include one or more selected from the group consisting of alcohols having 1 to 4 carbon atoms, ethyl acetate (EA), dichloromethane (DCM), and diethyl ether. In this case, the alcohols having 1 to 4 carbon atoms may include one or more selected from the group consisting of methanol, ethanol, n-propanol, 1,3-propanol, n-butanol, and isopropanol, and preferably may be water, methanol, isopropanol, ethyl acetate, or a mixture thereof.

[0111] According to one embodiment of the present invention, the ratio of sulfonyl group formation can be controlled by adjusting the reaction time between the compound represented by Formula 1 and the oxidizing agent. More specifically, when the reaction time between the compound represented by Formula 1 and the oxidizing agent is relatively short, a form in which the compound represented by Formula 1 and a compound containing a sulfonyl group coexist can be formed, and when the reaction time between the compound represented by Formula 1 and the oxidizing agent is relatively long, a form in which a compound containing only a sulfonyl group can be formed. At this time, the reaction time can be easily and appropriately changed and applied depending on the amount of the compound represented by Formula 1 and the oxidizing agent.

[0112] In addition, after the above reaction is completed, a step of drying the reaction product may be additionally included.

[0113] The above drying can be performed at room temperature or room temperature (20 to 25 ℃) for 12 to 96 hours, preferably 12 to 72 hours, more preferably 12 to 48 hours.

[0114] According to another aspect of the present invention, a NIPU foam manufactured according to the above manufacturing method is provided.

[0115] The foam according to one embodiment of the present invention is not rigid but flexible and possesses excellent compressibility and elasticity, so it can be applied to shoe midsoles as a replacement for conventionally commercialized polyurethane foam.

[0116]

[0117] The present invention will be described in more detail below with reference to preferred embodiments. However, it will be obvious to those skilled in the art that these embodiments are intended to explain the present invention more specifically and that the scope of the present invention is not limited by them.

[0118] The glycerol (>99% purity) and acetic acid (>99.7% purity) used in the following preparation examples and examples were purchased from Alfa Aesar, hydrogen bromide (Hydrobromic acid, HBr, 48%, ACS reagent) was purchased from Sigma Aldrich, and anhydrous MgSO4 (ultrapure water) and NaHCO3 (99~100.5% purity) were purchased from DAEJUNG Chemicals and Metals, and the reagents were used as is without further purification.

[0119] Preparation Example 1. Preparation of cyclic carbonate

[0120]

[0121] Glycerol (C3H5(OH)3, 10 mmol) and hydrogen bromide (hydrobromonic acid, HBr, 100 mmol) were mixed in a molar ratio of 1:10, and acetic acid (1 mmol) corresponding to 10 mol% of glycerol was added to the mixture. Next, 7 mL of the mixture was transferred to a PTFE chamber and hydrothermal synthesis was performed by heating at 100 °C for 12 hours to perform glycerol bromination. Next, NaOH was used in a CO2 capture process to produce NaHCO3, and the produced NaHCO3 (10 mmol) was reacted with the brominated glycerol to prepare a cyclic carbonate compound represented by the following chemical formula 3a.

[0122] [Chemical Formula 3a]

[0123]

[0124] Preparation Example 2. Preparation of a compound represented by Chemical Formula 2a

[0125]

[0126] The compound represented by Chemical Formula 3a (50 g, 276.2 mmol), the compound represented by Chemical Formula 4a (tris(3-mercaptopropionate, 36.7 g, 92.1 mmol), and the alkali metal compound (K2CO3, 38.2 g, 276.2 mmol) were placed in a 100 mL single-neck flask, dissolved in DMF (50 mL), and stirred at room temperature (RT) for 6 hours. After stirring was completed, the reaction product was transferred to a separatory funnel and extracted using ethyl acetate (EA) and deionized water (DI). After extraction, the organic layer was collected, and the residue was removed using sodium sulfate anhydrous (Na2SO4). Next, the solvent (EA) was evaporated under reduced pressure using a rotary evaporator, and the product was further dried in a vacuum oven at room temperature (RT) for 24 hours to obtain the product according to the present invention A compound represented by chemical formula 2a was prepared, and the yield is 92%.

[0127] Preparation Example 3. Preparation of a compound represented by Chemical Formula 2b

[0128]

[0129] Potassium peroxymonosulfate (KHSO5) was added as an oxidizing agent to the compound represented by Chemical Formula 2a prepared in Preparation Example 2 above to prepare a compound represented by Chemical Formula 2b according to the present invention.

[0130] Example 1. Preparation of NIPU 1 form represented by Chemical Formula 1a

[0131]

[0132] The compound represented by Formula 2a prepared in Preparation Example 2 above (2.5 g, 3.6 mmol), hydrotalcite (0.31 g), DBU (0.082 g, 0.5 mmol), and a foaming agent (deionized water (H2O), 0.048 g, 2.7 mmol) were mixed. Then, the mixture was homogenized by stirring at 2,000 rpm for 1.5 minutes. Subsequently, the compound represented by Formula 5a (0.47 g, 4 mmol) was added to the homogenized mixture and mixed for an additional 1 minute. 3.41 g of the mixture was [addressed] at 21.3, 14.3, and 7.57 cm, respectively. 3 The volume was injected into a container having the volume, the container was covered with a lid having a small vent to remove CO2 generated by blowing gas, and reacted at 100°C for 3 hours to produce NIPU 1a, 1b, and 1c foams represented by Chemical Formula 1a according to the present invention having the density of Table 1 below.

[0133] [Table 1]

[0134]

[0135] Example 2. Preparation of NIPU 2 form represented by Chemical Formula 1b

[0136]

[0137] The compound represented by Formula 2a prepared in Preparation Example 2 above (2.5 g, 3.6 mmol), hydrotalcite (0.31 g), DBU (0.082 g, 0.5 mmol), and foaming agent (deionized water (H2O), 0.048 g, 2.7 mmol) were mixed. Then, the mixture was homogenized by stirring at 2,000 rpm for 1.5 minutes. Subsequently, the compound represented by Formula 5b (0.54 g, 4 mmol) was added to the homogenized mixture and mixed for an additional 1 minute. 3.48 g of the mixture was applied to 20.8, 15.1, and 10.2 cm, respectively. 3The volume was injected into a container having the volume, and the container was covered with a lid having a small vent to remove CO2 generated by blowing gas, and reacted at 100°C for 3 hours to produce NIPU 2a, 2b, and 2c foams represented by Formula 1b according to the present invention having the density of Table 2 below.

[0138] [Table 2]

[0139]

[0140] Example 3. Preparation of NIPU 3 form represented by Chemical Formula 1c

[0141]

[0142] An oxidizing agent (Oxone, > ca. 45%(T) as KHSO5, 33.8 g) was dissolved in ethanol (100 mL) to prepare a 1 M oxidizing agent solution. Then, NIPU 1 form (1.84 g, 8 cm) represented by Formula 1a prepared in Example 1 above was used. 3 The foam was immersed in the oxidizing agent solution for 24 hours. Afterward, the foam was washed with pure ethanol to remove any remaining oxidizing agent, and dried at room temperature (24 ℃) for 24 hours to produce NIPU 3a, 3b, and 3c foams represented by Formula 1c according to the present invention, having the density shown in Table 3 below.

[0143] [Table 3]

[0144]

[0145] Example 4. Preparation of NIPU 4 forms represented by Chemical Formula 1a and Chemical Formula 1c

[0146]

[0147] An oxidizing agent (Oxone, > ca. 45%(T) as KHSO5, 33.8 g) was dissolved in ethanol (100 mL) to prepare a 1 M oxidizing agent solution. Then, NIPU 1 form (1.84 g, 8 cm) represented by Formula 1a prepared in Example 1 above was used. 3 ) was individually immersed in the above oxidizing agent solution for 1, 2, 4, and 6 hours, respectively. Afterwards, the foam was washed with pure ethanol to remove the remaining oxidizing agent and dried at room temperature (24 ℃) for 24 hours to produce NIPU 4a, 4b, 4c, and 4d foams represented by Formula 1a and Formula 1c according to the present invention, having the densities shown in Table 4 below.

[0148] [Table 4]

[0149]

[0150] Experimental Example 1. Confirmation of Compound Preparation

[0151] To confirm that the NIPU foam prepared according to the present invention was produced, for compounds 1a, 1b, 1c and the mixed foam of 1a and 1c prepared in Examples 1 to 4, FT-IR spectra (Nicolet IS5 spectrometer, Thermo Fisher Scientific) equipped with a transmission or diamond attenuated total reflectance (ATR) device were analyzed at 4000–500 cm⁻¹. -1 Measurements were taken based on the average of 16 scans within the range, and the results are as shown in Figures 1 to 4.

[0152] Referring to FIGS. 1 and 2, (a) the -C=O bond peak (blue band) of the cyclic carbonate before the reaction is confirmed, but (b) after the reaction is completed, the -C=O peak (pink band) of the compound represented by Formula 1a and Formula 1b is formed, thereby confirming that the compound represented by Formula 1a and Formula 1b according to the present invention has been prepared.

[0153] In addition, referring to FIGS. 3 and 4, it can be confirmed that a compound represented by Formula 1c according to the present invention was prepared through the formation of a sulfonyl group (-SO2) peak.

[0154] Experimental Example 1. Verification of Morphology and Physical Properties

[0155] 1.1. Morphology and Cell Size

[0156] To determine the morphology and cell size of the NIPU foam prepared according to the present invention, the average diameter of each sample of the NIPU 1a to 1c foams and NIPU 2a to 2c foams prepared in Examples 1 and 2 was measured and determined using a scanning electron microscope (SEM, Carl Zeiss Sigma instrument microscope), and then analyzed using ImageJ software for accurate quantification. The results are shown in Table 5, Figure 5, and Figure 6 below.

[0157] [Table 5]

[0158]

[0159] Referring to Table 5 and Fig. 5 above, NPIU forms 1a, 1b, and 1c to which the amine compound represented by Chemical Formula 5a is applied have 160, 234, and 450 kg / m², respectively. 3 It can be confirmed that they have a density of 0.36±0.14, 0.32±0.12, and 0.27±0.11 mm, respectively.

[0160] Referring to Table 5 and Fig. 6 above, NIPU forms 2a, 2b, and 2c, to which the amine compound represented by Chemical Formula 5b is applied, yield 167, 230, and 342 kg / m³, respectively. 3 It can be confirmed that they have a density of 0.41±0.24, 0.37±0.12, and 0.25±0.11 mm, respectively.

[0161] As seen in the above results, it can be confirmed that the NIPU foam according to the present invention has an open cell structure in which CO2 formed during foam manufacturing is removed by blowing gas. In addition, the cell size can be more easily controlled by adjusting the formation of a polymer (Chemical Formula 1) network formed according to the density of the NIPU foam and the amine compound applied to the NIPU foam, and by controlling the cell size, it can be applied to various cushioning materials.

[0162] 1.2. Glass transition temperature (T g , ℃)

[0163] Glass transition temperature (T) of NIPU foam manufactured according to the present invention g To verify ), the glass transition temperature was measured for the NIPU 1a to 1c foams and NIPU 2a to 2c foams prepared in Examples 1 and 2 above.

[0164] More specifically, using a DSC250 calorimeter from TA Instruments, NIPU 1a to 1c foams and NIPU 2a to 2c foam samples (10 mg) prepared in Examples 1 and 2 were measured at a heating rate of 10 ℃ / min in a temperature range of -30 to 80 ℃, and the results are as shown in Table 6, Figure 7, and Figure 8 below.

[0165] [Table 6]

[0166]

[0167] Referring to Table 6 and FIG. 7 above, (a) NIPU 1a foam, (b) NIPU 1b foam, and (c) NIPU 1c foam prepared in Example 1 according to the present invention have glass transition temperatures (T) of 9.0, 9.6, and 7.4 °C, respectively. g It can be confirmed that it has ).

[0168] In addition, referring to Table 6 and FIG. 8 above, (a) NIPU 2a foam, (b) NIPU 2b foam, and (c) NIPU 2c foam prepared in Example 2 according to the present invention have glass transition temperatures (T) of 28.5, 23.8, and 26.6 °C, respectively. g It can be confirmed that it has ).

[0169] Through the above results, it can be confirmed that the non-isocyanate polyurethane according to the present invention has excellent thermal properties.

[0170] 1.3. 5% Pyrolysis Temperature

[0171] To determine the pyrolysis temperature of the NIPU foam prepared according to the present invention, the 5% pyrolysis temperature (T) of the NIPU foams 1a to 1c prepared in Examples 1 and 2 and the NIPU foams 2a to 2c d5% ,°C) was checked.

[0172] More specifically, analysis was performed using a thermogravimetric analyzer (TGA, PerkinElmer TGA 4000) in nitrogen. NIPU Forms 1a to 1c and NIPU Forms 2a to 2c samples (10 mg) prepared in Examples 1 and 2 were placed in a pan, and a TGA run was performed at a constant heating rate of 10 °C / min in a temperature range of 25 to 400 °C to determine the 5% thermal decomposition temperature (T d5% ,°C) was checked. At this time, the above 5% thermal decomposition temperature (T d5% ,°C) is the 5% weight loss temperature of the sample, which means the temperature at which the weight loss is measured while heating the sample and the weight loss reaches 5% by weight, and the results are as shown in Table 7 and Figures 9 and 10 below.

[0173] [Table 7]

[0174]

[0175] Referring to Table 7 and Figure 9 above, it can be seen that (a) NIPU 1a foam, (b) NIPU 1b foam, and (c) NIPU 1c foam prepared in Example 1 according to the present invention have 5% pyrolysis temperatures of 187.17, 201.33, and 198.83 °C, respectively.

[0176] In addition, referring to Table 7 and Figure 10 above, it can be seen that (a) NIPU 2a foam, (b) NIPU 2b foam, and (c) NIPU 2c foam prepared in Example 2 according to the present invention have 5% pyrolysis temperatures of 201.19, 199.83, and 209.00 ℃, respectively.

[0177] Through the above results, it can be confirmed that the NPIU foam according to the present invention has excellent thermal stability.

[0178] Experimental Example 2. Repeated Compressive Stress Test

[0179] 2.1.

[0180] To verify the compression performance of the NIPU foam according to the present invention, a universal testing machine (UTM, Instron-5543) equipped with a 1 kN load cell was used for the NIPU 1a foam and NIPU 2a foam prepared in Examples 1 and 2.

[0181] More specifically, the NIPU 1a foam and NIPU 2a foam prepared in Examples 1 and 2 are 3.375 cm 3It was cut into a cube shape with a volume and subjected to a repetitive compression test at a speed of 1 mm / min. During this process, loading and unloading were performed at a speed of 10 mm / min, and strains between 0 and 60% were measured and identified as energy loss values. In this case, the energy loss value refers to the energy required to compress the foam and restore it to its original state; the smaller the energy loss value, the faster the foam returns to its original state without energy loss, and the results are shown in Fig. 11.

[0182] Referring to Fig. 11, it can be seen that the NIPU 1a foam (blue line) prepared in Example 1 has an energy loss value of 16.9%, and the NIPU 2a foam (orange line) prepared in Example 2 has an energy loss value of 24.8%. In other words, the NIPU 1a foam prepared in Example 1 contains more soft alkyl chains, so it can be said to have superior compression recovery power compared to the NIPU 2a foam prepared in Example 2.

[0183] 2.2.

[0184] To confirm that the compression performance of the NIPU foam according to the present invention can be controlled, the NIPU 4a foam to NIPU 4d foam prepared in Example 4 was tested using a universal testing machine (UTM, Instron-5543) equipped with a 1 kN load cell in the same manner as in Experimental Example 2.1, and the results are as shown in FIG. 12.

[0185] Referring to FIG. 12, it can be seen that the strength of the NIPU foam increases as the amount of the compound represented by chemical formula 1c containing a sulfonyl group (=SO2) increases. Through the above results, it can be confirmed that the stiffness of the NIPU foam according to the present invention can be controlled by controlling the functional groups within the NIPU foam.

[0186] Experimental Example 3. Compressive stress test according to density

[0187] To determine the compression modulus according to density in the NIPU foam according to the present invention, a universal testing machine (UTM, Instron-5543) equipped with a 1 kN load cell was used for the NIPU 1a, 1b, and 1c foams prepared in Example 1 and a conventional commercially available isocyanate-based PU foam (polymerization of Daesung Chemical's MR-5460 system polyol and MP-5460 NCO prepolymer).

[0188] More specifically, the NIPU 1a foam (dark blue line), 1b (light blue line) to 1c foams (orange line) prepared in Example 1 and a conventional commercially available PU (dot line) are 3.375 cm 3 It was cut into a cube shape with a volume of . Then, a compression test was performed at a speed of 1 mm / min. At this time, the compression modulus was determined in the linear region of the stress-strain curve, particularly at 10 to 15% strain, and the results are shown in Fig. 13.

[0189] Referring to FIG. 13, it can be seen that the NIPU 1a foam, 1b foam, and 1c foam manufactured in Example 1 according to the present invention have an excellent compression effect. In particular, it can be seen that as the density of the NIPU 1a foam, 1b foam, and 1c foam gradually increases, the capacity to withstand greater force at the same strain rate improves, thereby exhibiting a cushioning effect capable of withstanding higher loads.

[0190] Experimental Example 4. Compressive modulus test

[0191] 4.1.

[0192] In order to compare the compressive modulus between the NIPU foam according to the present invention and conventional PU and NIPU foams having characteristics as shown in Table 9 below, a test for the compressive modulus was performed for each.

[0193] At this time, the compression modulus was evaluated using a universal testing machine (UTM, Instron-5543) equipped with a 1 kN load cell. The NIPU foam according to the present invention and the conventional PU foam were generally cut into cube shapes of various volumes, and compression tests were performed at a speed of 10 mm / min in the strain range of 0 to 70%. In addition, the compression modulus was measured in the linear region of the stress-strain curve, particularly in the strain range of 10 to 15%, and the results are as shown in FIG. 14.

[0194] [Table 8]

[0195]

[0196] Table 8 above, Ref [1] to [4] are as follows.

[0197] [1] Yang, G., Liu, X. & Lipik, V. Evaluation of silica aerogel-reinforced polyurethane foams for footwear applications. J. Mater. Sci. 53, 9463-9472 (2018).

[0198] [2] Purwanto, NS, Chen, Y. & Torkelson, J.M. Biobased, reprocessable, self-blown non-isocyanate polyurethane foams: Influence of blowing agent structure and functionality. Eur. Polym. J. 206, 112775 (2024).

[0199] [3] Purwanto, N.S., Chen, Y., Wang, T. & Torkelson, J.M. Rapidly synthesized, self-blowing, non-isocyanate polyurethane network foams with reprocessing to bulk networks via hydroxyurethane dynamic chemistry. Polymer (Guildf). 272, 125858 (2023).

[0200] [4] Bourguignon, M., Grignard, B. & Detrembleur, C. Water-induced self-blown non-isocyanate polyurethane foams. Angew. Chemie Int. Ed. 61, e202213422 (2022).

[0201] Referring to FIG. 14, the NIPU 1c foam prepared in Example 1 according to the present invention has a density (450 kg / m³) capable of maintaining flexibility. 3 It can be confirmed that it achieves a high compression modulus of 2.02 MPa within ) and has a compression modulus that is almost similar to that of conventional commercially available isocyanate-based PU foam applied to midsoles.

[0202] Based on the above results, it can be said that the NIPU foam according to the present invention is a foam with the potential to replace commercially available PU foam in various cushioning fields in the future.

[0203] 4.2.

[0204] In order to compare the compressive elasticity between the NIPU foam containing a sulfonyl group according to the present invention and the conventional PU and NIPU foams having characteristics as shown in Table 9, tests were performed on the compressive elasticity of the NIPU 4a foam to NIPU 4d foam prepared in Example 4 and Ref [1] to [4], and the results are as shown in FIG. 15.

[0205] Referring to FIG. 15, the NIPU 4a to NIPU 4d foams manufactured in Example 4 according to the present invention can be seen to have a large increase in strength compared to conventional commercially available isocyanate-based PU foams and non-isocyanate-based NIPU foams.

[0206] Based on the above results, it can be anticipated that the strength of the NIPU foam according to the present invention can be adjusted to suit the field of application by appropriately mixing it.

[0207] From the foregoing description, those skilled in the art to which the present invention pertains will understand that the present invention may be implemented in other specific forms without altering its technical concept or essential features. In this regard, the embodiments described above should be understood as illustrative in all respects and not restrictive.

Claims

1. A step of preparing a compound represented by the following chemical formula 2 by reacting a compound represented by the following chemical formula 3 and a compound represented by the following chemical formula 4; and A method for manufacturing a non-isocyanate polyurethane (NIPU) foam comprising the step of reacting a compound represented by Chemical Formula 2 above and a compound represented by Chemical Formula 5 below to produce a compound represented by Chemical Formula 1 below: [Chemical Formula 1] [Chemical Formula 2] [Chemical Formula 3] [Chemical Formula 4] [Chemical Formula 5] In the above chemical formulas 1 to 5, R1 is -(C=O)-(C1-C6alkylene)-S-(CH2)- or -(C=O)-(C1-C6alkylene)-SO2-(CH2)-, and R2 is -(C1-C4alkylene)-O-[R1-CH(CH3OH)-O-(C=O)-NH-R3-NH-(C=O)-O-CH2-CH(OH)-R1] n - or -(C1-C6-alkyl) and, R3 is -(C1-C 12 Alkylene)- or -(C1-C6alkylene)-aryl-(C1-C6alkylene)- and, R4 is -(C1-C6-alkyl) or -(C1-C4alkylene)-O-(C=O)-(C1-C6alkylene)-S-(C3O3H3), and R5 is -(C=O)-(C1-C6alkylene)-SH or -(C=O)-(C1-C6alkylene)-SO2H, and R6 is -(C1-C 4- It is alkylene)-(O)-R5 or -(C1-C6-alkyl), and X is -I, -Br, -Cl, or -OH, and n is an integer from 1 to 10.

2. In Paragraph 1, In the above chemical formulas 1 to 5, R1 is -(C=O)-(C1-C4 alkylene)-S-(CH2)- or -(C=O)-(C1-C6 alkylene)-SO2-(CH2)-, and R2 is -(C1-C4alkylene)-O-[R1-CH(CH3OH)-O-(C=O)-NH-R3-NH-(C=O)-O-CH2-CH(OH)-R1] n - or -(C1-C4-alkyl) and, R3 is -(C1-C8alkylene)- or -(C1-C4alkylene)-aryl-(C1-C4alkylene)-, and R4 is -(C1-C4-alkyl) or -(C1-C4alkylene)-O-(C=O)-(C1-C4alkylene)-S-(C3O3H3), and R5 is -(C=O)-(C1-C4 alkylene)-SH or -(C=O)-(C1-C6 alkylene)-SO2H, and R6 is -(C1-C 4- It is alkylene)-(O)-R5 or -(C1-C6-alkyl), and X is -Br or -Cl, and A method for manufacturing NIPU foam where n is an integer from 1 to 10.

3. In Paragraph 1, The step of preparing a compound represented by the above chemical formula 2 is: A step of mixing the compound represented by Chemical Formula 3 and the compound represented by Chemical Formula 4; and A method for manufacturing NIPU foam comprising the step of reacting the above mixture in the presence of a base.

4. In Paragraph 3, A method for manufacturing NIPU foam in which the above base is an alkaline metal compound, a nitrogen-containing compound, or a mixture thereof.

5. In Paragraph 4, A method for manufacturing NIPU foam in which the above alkali metal compound is one or more selected from the group consisting of K(OH), K2CO3, NaCO3, LiCO3, MgCO3, Ca(OH)2, and CaCO3.

6. In Paragraph 4, The above nitrogen-containing compound is A method for manufacturing NIPU foam, wherein one or more types selected from the group consisting of and (NH4)3CO3.

7. In Paragraph 1, The step of preparing a compound represented by the above chemical formula 1 is, A step of adding a catalyst to a compound represented by the above chemical formula 2; and The method comprises the step of reacting the catalyst mixture with the compound represented by Chemical Formula 5; A method for manufacturing NIPU foam in which the above reaction is performed at 80 to 120 ℃.

8. In Paragraph 7, The above catalysts are 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5-Diazabicyclo[4.3.0]non-5-ene (DBN), and 1,4-diazabicyclo[2.2.2]octane (DABCO). A method for manufacturing NIPU, wherein one or more are selected from the group consisting of K2CO3, Na2CO3, CaCO3, Li2CO3, (NH4)2CO3, MgCO3, KOH, and NaOH.

9. In Paragraph 1, After the step of preparing the compound represented by the above chemical formula 1, A method for manufacturing NIPU foam, further comprising the step of reacting a compound represented by the above chemical formula 1 with an oxidizing agent.

10. In Paragraph 9, A method for manufacturing NIPU foam, wherein the oxidizing agent comprises one or more selected from the group consisting of potassium peroxymonosulfate (KHSO5), m-chloroperoxybenzoic acid (m-CPBA), hydrogen peroxide (H2O2), 2-iodoxybenzoic acid (IBX), and potassium persulfate (K2S2O8).

11. Non-isocyanate polyurethane (NIPU) foam manufactured according to the manufacturing method of any one of claims 1 to 10.

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