Manufacturing method of eco-friendly sponge with excellent deodorizing effect

Abstract

The present invention relates to a method for manufacturing an eco-friendly sponge with excellent deodorizing effect, and more specifically, comprises a raw material mixing step of mixing a bio-polyol, an isocyanate, a waste raw material, a surfactant, a filler, a chain extender, a crosslinking agent, and a foaming agent; a foaming step of foaming the mixture prepared through the raw material mixing step; and a cutting step of cutting the foamed body produced through the foaming step, wherein the waste raw material consists of one or more selected from the group consisting of waste polyethylene terephthalate and recycled polyol. The sponge manufactured through the above process is not only eco-friendly by recycling waste materials, but also possesses excellent deodorizing effects, mechanical properties, and flame retardancy.

Description

Technology Field

[0001] The present invention relates to a method for manufacturing an eco-friendly sponge with excellent deodorizing effect, and more specifically, to a method for manufacturing an eco-friendly sponge that is not only eco-friendly by recycling waste raw materials but also has excellent deodorizing effect, mechanical properties, and flame retardancy. Background Technology

[0003] Polyurethane is known as a group of polymers produced by the addition polymerization of diisocyanates. Unlike most other polymers such as PE, PVC, PP, and PS, it is not a polymer with repeating units, so there is no empirical formula that represents the whole. It can be viewed as a polymer having a compound with active hydrogen, such as a hydroxyl group or an amino group, and a urethane group (-NH-COO-) formed by the addition of an isocyanate.

[0004] A unique characteristic of polyurethane that distinguishes it from other polymers is that, unlike other polymers, the individual components constituting the molecule—namely active hydrogen compounds and isocyanates—can be selected in diverse ways, and secondly, it is possible to manufacture intermediate prepolymers designed with desired structures and perform polymerization using them.

[0005] Therefore, polyurethane facilitates the manufacturing of products with various processing conditions and required performance characteristics. Its strength can be enhanced by compression, allowing it to be applied as an interior or exterior material for automobiles or as an insulating material for buildings. Furthermore, by improving wear resistance, it can be used for insoles, outsoles, and footwear, and can also be utilized in household goods such as sponges.

[0006] However, conventional polyurethane had a problem in that mechanical properties, such as tensile strength, were low due to pores present within the polyurethane during the compression process.

[0007] Meanwhile, polyethylene terephthalate (PET), a thermoplastic, is a representative plastic material currently used not only as fibers but also for films, bottles, and injection molding materials. As it is one of the highest-demand polymer materials with rapidly increasing production volume, the disposal of waste polyethylene terephthalate generated during the production process and after use poses a significant problem due to severe environmental pollution. Conventional methods for treating waste polyethylene terephthalate include physical treatment, specifically dissolving it to use in other objects such as containers, construction materials, and carpets. However, given current domestic economic conditions, there is low demand for utilizing waste materials as is; furthermore, the manufacturing costs of recycled products are excessively high, and the physical properties of the produced recycled goods result in low demand. Prior art literature

[0009] Korean Patent Registration No. 10-0506342 (July 28, 2005) Korean Patent Registration No. 10-1844092 (March 26, 2018) The problem to be solved

[0010] The objective of the present invention is to provide a method for manufacturing a sponge that is not only eco-friendly by recycling waste raw materials but also has excellent deodorizing effect, mechanical properties, and flame retardancy. means of solving the problem

[0012] The objective of the present invention can be achieved by providing a method for manufacturing an eco-friendly sponge with excellent deodorizing effect, comprising a raw material mixing step of mixing a bio-polyol, an isocyanate, a waste raw material, a surfactant, a filler, a flame retardant, a chain extender, a crosslinking agent, and a foaming agent; a foaming step of foaming the mixture produced through the raw material mixing step; and a cutting step of cutting the foamed body produced through the foaming step, wherein the waste raw material comprises one or more selected from the group consisting of waste polyethylene terephthalate and recycled polyol.

[0013] According to a preferred feature of the present invention, the raw material mixing step is performed by mixing 100 parts by weight of bio-polyol, 40 to 60 parts by weight of isocyanate, 5 to 10 parts by weight of waste raw material, 1 to 3 parts by weight of surfactant, 1 to 3 parts by weight of filler, 0.5 to 1.5 parts by weight of flame retardant, 1 to 3 parts by weight of chain extender, 0.5 to 1.5 parts by weight of crosslinking agent, and 5 to 20 parts by weight of foaming agent.

[0014] According to a more preferred feature of the present invention, the bio-polyol is composed of an epoxidized vegetable oil, and the vegetable oil is composed of one or more selected from the group consisting of castor oil, resquerella oil, palm oil, rapeseed oil, sunflower oil, and soybean oil.

[0015] According to a more preferred feature of the present invention, the surfactant is composed of one or more selected from the group consisting of 1,3-dimethylbutylamine, polydimethylsiloxane, polyoxyalkylene block copolymer, silicate oxide, silicone oil, and nonylphenol ethoxylate.

[0016] According to a more preferred feature of the present invention, the filler is composed of one or more selected from the group consisting of expanded vermiculite, maifan stone, zeolite, illite, smectite, and kaolin.

[0017] According to a more preferred feature of the present invention, the chain extender comprises one or more selected from the group consisting of piperazine, diol, and diamine.

[0018] According to a more preferred feature of the present invention, the crosslinking agent is composed of one or more selected from the group consisting of triols, tetraols, and polyamines.

[0019] According to a more preferred feature of the present invention, the blowing agent is composed of one or more selected from the group consisting of cyclopentane, dichlorofluoroethane, fluorocarbon, methyl formate, and hydrofluoroolefin. Effects of the invention

[0021] The method for manufacturing an eco-friendly sponge with excellent deodorizing effect according to the present invention is not only eco-friendly by recycling waste raw materials, but also exhibits an excellent effect of providing a sponge with excellent deodorizing effect, mechanical properties, and flame retardancy. Brief explanation of the drawing

[0023] Figure 1 is a flowchart illustrating a method for manufacturing an eco-friendly sponge with excellent deodorizing effect according to the present invention. Figure 2 is a photograph showing a mat made of an eco-friendly sponge with excellent deodorizing effect according to the present invention. Specific details for implementing the invention

[0024] Hereinafter, preferred embodiments of the present invention and the physical properties of each component are described in detail. This description is intended to be sufficient for a person skilled in the art to easily practice the invention, and does not imply that the technical scope and concept of the present invention are limited thereby.

[0026] The method for manufacturing an eco-friendly sponge with excellent deodorizing effect according to the present invention comprises a raw material mixing step (S101) of mixing a bio-polyol, an isocyanate, a waste raw material, a surfactant, a filler, a chain extender, a crosslinking agent, and a foaming agent; a foaming step (S103) of foaming the mixture prepared through the raw material mixing step (S101); and a cutting step (S105) of cutting the foamed body produced through the foaming step (S103).

[0028] The above raw material mixing step (S101) is a step of mixing bio-polyol, isocyanate, waste raw material, filler, surfactant, chain extender, crosslinking agent, and foaming agent, and is preferably performed by mixing 100 parts by weight of bio-polyol, 40 to 60 parts by weight of isocyanate, 5 to 10 parts by weight of waste raw material, 1 to 3 parts by weight of surfactant, 1 to 3 parts by weight of filler, 0.5 to 1.5 parts by weight of flame retardant, 1 to 3 parts by weight of chain extender, 0.5 to 1.5 parts by weight of crosslinking agent, and 5 to 20 parts by weight of foaming agent.

[0029] The above bio-polyol is composed of epoxidized vegetable oil and is manufactured into polyurethane by reacting with the above isocyanate. Generally, vegetable oil has a triacylglycerol (glyceride) structure with a glycerol structure as the main chain and has a side chain structure containing multiple hydroxyl groups in various fatty acids derived from carboxylic acids. The above vegetable oil is synthesized into a polyol through an epoxidation reaction process to produce a bio-polyol.

[0030] More specifically, the above epoxidation reaction is a reaction for synthesizing epoxy rings in vegetable oil, wherein vegetable oil, acetic acid, purified amberlite, and toluene are stirred, the amberlite is filtered, washed with distilled water, the aqueous layer is removed using a separating funnel, and residual water is removed from the oil layer using sodium sulfate, and subsequently, toluene is removed using a distillation concentration device, thereby obtaining epoxidized vegetable oil, and ethylene glycol, distilled water, isopropanol, and tetrafluoroboric acid are mixed with the epoxidized vegetable oil, wherein the hydroxyl group is controlled by the amount of tetrafluoroboric acid, and finally, the reaction is terminated by dropping ammonia until the pH becomes neutral, then isopropanol is removed using a distillation concentration device, the oil layer is filtered using a separating funnel, toluene is added to the oil layer to dissolve it, residual water is removed using sodium sulfate, and toluene is removed using a distillation concentration device, thereby synthesizing a biopolyol.

[0031] At this time, it is preferable that the vegetable oil consists of one or more selected from the group consisting of castor oil, resquerella oil, palm oil, rapeseed oil, sunflower oil, and soybean oil.

[0032] The above isocyanate is contained in an amount of 40 to 60 parts by weight, and is preferably composed of one or more selected from the group consisting of isophron diisocyanate (IPDI), hexamethylene diisocyanate, methyl cyclohexane diisocyanate, xylene diisocyanate, diphenyl diisocyanate, and 1,5-naphthalene diisocyanate. If the content of the isocyanate is less than 40 parts by weight, the synthesis of polyurethane does not proceed sufficiently, and the physical properties of the sponge deteriorate excessively. If the content of the isocyanate exceeds 60 parts by weight, an excessive amount of unreacted isocyanate remains, which is undesirable.

[0033] The above waste raw material is contained in an amount of 5 to 10 parts by weight and consists of one or more selected from the group consisting of waste polyethylene terephthalate and recycled polyol, and plays a role in providing an eco-friendly sponge by recycling waste polyethylene terephthalate and recycled polyol that are disposed of.

[0034] At this time, the waste polyethylene terephthalate is preferably used to exhibit thermoplasticity, and is applied in a molten state after being heated above its melting point. The recycled polyol is preferably synthesized from waste polyurethane, and as an example, it is preferable to use one synthesized through Korean Patent Registration No. 10-0893355.

[0035] When waste raw materials composed of the above-mentioned components are mixed, a sponge with excellent mechanical properties as well as being eco-friendly can be provided. However, if the content of the waste raw materials is less than 5 parts by weight, the above effect is negligible, and if the content of the waste raw materials exceeds 10 parts by weight, the above effect is not significantly improved, and physical properties such as elasticity of the sponge produced through the present invention may be degraded, which is undesirable.

[0036] The above surfactant is contained in an amount of 1 to 3 parts by weight and consists of one or more selected from the group consisting of 1,3-dimethylbutylamine, polydimethylsiloxane, polyoxyalkylene block copolymer, silicate oxide, silicone oil, and nonylphenol ethoxylate, and controls the pore structure of the sponge produced through the present invention, and the raw material mixing step serves to ensure that each component mixed through the step is evenly mixed to exhibit uniform physical properties.

[0037] If the content of the surfactant is less than 1 part by weight, the above effect is negligible, and if the content of the surfactant exceeds 3 parts by weight, the above effect is not significantly improved, and the mechanical properties of the sponge may be excessively degraded, which is undesirable.

[0038] The above filler is contained in an amount of 1 to 3 parts by weight and consists of one or more selected from the group consisting of expanded vermiculite, maifan stone, zeolite, illite, smectite, and kaolin. The filler composed of the above components not only improves the mechanical properties of the sponge produced through the present invention but also serves to impart deodorizing performance.

[0039] The aforementioned expanded vermiculite exhibits an excellent deodorizing effect due to its cation adsorption properties, while the aforementioned maifan stone, zeolite, illite, smectite, and kaolin exhibit an excellent deodorizing effect because their porous properties trap odor-causing particles within the pore layers.

[0040] If the content of the above filler is less than 1 weight part, the above effect is negligible, and if the content of the above filler exceeds 3 weight parts, the above effect is not significantly improved and the mechanical properties of the sponge may actually deteriorate, so it is undesirable.

[0041] The flame retardant is contained in an amount of 0.5 to 1.5 parts by weight and is preferably composed of one or more selected from the group consisting of expanded graphite, sodium silicate, potassium hydroxide, aluminum hydroxide, and aluminum oxide, and the flame retardant composed of the above components serves to impart flame retardant performance to the sponge manufactured through the present invention.

[0042] If the content of the flame retardant is less than 0.5 parts by weight, the above effect is negligible, and if the content of the flame retardant exceeds 1.5 parts by weight, the above effect is not significantly improved, and the mechanical properties of the sponge may be excessively degraded, which is undesirable.

[0043] The above chain extender is contained in an amount of 1 to 3 parts by weight and consists of one or more selected from the group consisting of piperazine, diol, and diamine. Since it extends the chain of polyurethane, which is a major component of the sponge produced through the present invention, and increases the molecular weight, it exhibits the effect of improving the mechanical properties of the sponge.

[0044] If the content of the chain extender is less than 1 part by weight, the above effect is negligible, and if the content of the chain extender exceeds 3 parts by weight, the above effect is not significantly improved, and the amount of unreacted chain extender remaining in the sponge increases excessively, which may degrade the physical properties of the sponge, so it is undesirable.

[0045] The above-mentioned crosslinking agent is contained in an amount of 0.5 to 1.5 parts by weight and consists of one or more selected from the group consisting of triols, tetraols, and polyamines, and plays a role in carrying out the crosslinking reaction of the polyurethane chains, which are the main components of the sponge produced through the present invention, so as to provide a sponge with significantly improved mechanical properties such as tensile strength and wear resistance.

[0046] If the content of the crosslinking agent is less than 0.5 parts by weight, the above effect is negligible, and if the content of the crosslinking agent exceeds 1.5 parts by weight, the above effect is not significantly improved, and the amount of bio-polyol and isocyanate is reduced excessively, which may result in a decrease in the production amount of polyurethane constituting the sponge, so it is undesirable.

[0047] The above foaming agent is contained in an amount of 5 to 20 parts by weight and consists of one or more selected from the group consisting of cyclopentane, dichlorofluoroethane, fluorocarbon, methyl formate, and hydrofluoroolefin, and plays a role in foaming the polyurethane produced by the reaction of the biopolyol and isocyanate to form a sponge shape.

[0048] The foaming agent composed of the above components exhibits an excellent foaming effect on polyurethane while having very low ozone depletion potential and global warming potential, serving to provide an eco-friendly method for manufacturing sponges.

[0049] In particular, it is preferable that the blowing agent comprises a mixture of methyl formate and hydrofluoroolefin in a ratio of 1:2 to 4 parts by weight. When composed of the above components, it exhibits the effect of being environmentally friendly, preventing sponge shrinkage, and not excessively increasing manufacturing costs. To explain in more detail, hydrofluoroolefin is environmentally friendly because it has a Global Warming Potential (GWP) of 10 or less, specifically 5 or less, and an Ozone Depletion Potential (ODP) of 0. Furthermore, methyl formate is cheaper than conventionally used fluorine-based blowing agents, and as an environmentally friendly blowing agent with an ODP and GWP of 0, it exhibits a k-factor similar to that of hydrochlorofluorocarbon-based blowing agents. However, sponges with methyl formate have a problem in that they are difficult to apply because the methyl formate reacts with water to produce formic acid, causing the foam to shrink due to plasticization. But as described above, when mixed with hydrofluoroolefin, the plasticity of methyl formate is minimized, the ODP and GWP are low, and manufacturing costs can be significantly reduced compared to the case where only hydrofluoroolefin is used.

[0050] As described above, when a foaming agent is contained in an amount of 5 to 20 parts by weight, it is possible to manufacture sponges of various densities with excellent mechanical properties and various foaming ratios.

[0051] At this time, if the content of the foaming agent is less than 5 parts by weight, the foaming effect is negligible and it is difficult to manufacture it in the form of a sponge, and if the content of the foaming agent exceeds 20 parts by weight, excessive over-foaming occurs, which is undesirable because the mechanical properties of the sponge may be excessively degraded.

[0053] The foaming step (S103) is a step of foaming the mixture prepared through the raw material mixing step (S101). It is preferable that the mixture prepared through the raw material mixing step (S101) is introduced into a reactor and stirred at a speed of 1500 to 2000 rpm for 15 to 25 minutes to prepare the mixture, and then foams the prepared mixture after stirring at a speed of 5000 to 7000 rpm at a temperature of 24 to 26°C for 8 to 12 minutes.

[0054] If the temperature of the foaming step (S103) is less than 24℃ or the stirring speed is less than 5000 rpm, the foaming efficiency of the polyurethane foam is reduced, and if the temperature of the foaming step (S103) exceeds 26℃ or the stirring speed exceeds 7000 rpm, the foaming efficiency of the polyurethane foam is not significantly improved, and the manufacturing cost is increased, so it is undesirable.

[0055] At this time, the shape or thickness of the foamed body produced through the foaming step (S103) is not specifically limited and can be applied in various ways depending on the application.

[0057] The above cutting step (S105) is a step of cutting the foamed body produced through the above foaming step (S103), and it is preferable that the process be carried out by cooling the foamed body produced through the above foaming step (S103) to room temperature and cutting it after the foaming process is completed.

[0058] The foam mat produced through the above cutting step (S105) is shown in Figure 2 below.

[0060] Hereinafter, the method for manufacturing an eco-friendly sponge with excellent deodorizing effect according to the present invention and the physical properties of the sponge manufactured by said method will be explained with reference to examples.

[0062] <Example 1>

[0063] 100 parts by weight of bio-polyol (epoxylated castor oil), 50 parts by weight of isocyanate (isophron diisocyanate), 7.5 parts by weight of waste raw material (waste polyethylene terephthalate), 2 parts by weight of surfactant (1,3-dimethylbutylamine), 2 parts by weight of filler (expanded vermiculite), 1 part by weight of flame retardant (mixture of expanded graphite and sodium silicate in a 1:1 weight ratio), 2 parts by weight of chain extender (piperazine), 1 part by weight of crosslinking agent (triol), and 12.5 parts by weight of foaming agent (mixture of methyl formate and hydrofluoroolefin in a 1:3 weight ratio) are introduced into a reactor and stirred at a speed of 1800 rpm for 20 minutes to prepare a mixture, the prepared mixture is foamed by stirring at a speed of 6000 rpm for 10 minutes at a temperature of 25℃, and the foamed body is cross An eco-friendly sponge was manufactured by cutting it into 20mm × 20mm × 25mm thickness.

[0065] <Example 2>

[0066] An eco-friendly sponge was manufactured by mixing 40 parts by weight of isocyanate, 5 parts by weight of waste raw material, 1 part by weight of surfactant, 1 part by weight of filler, 0.5 parts by weight of flame retardant, 1 part by weight of chain extender, 0.5 parts by weight of crosslinking agent, and 20 parts by weight of foaming agent, in the same manner as in Example 1 above.

[0068] <Example 3>

[0069] An eco-friendly sponge was manufactured by mixing 60 parts by weight of isocyanate, 10 parts by weight of waste raw material, 3 parts by weight of surfactant, 3 parts by weight of filler, 1.5 parts by weight of flame retardant, 3 parts by weight of chain extender, 1.5 parts by weight of crosslinking agent, and 5 parts by weight of foaming agent, in the same manner as in Example 1 above.

[0071] <Comparative Example 1>

[0072] 100 parts by weight of polyether polyol, 50 parts by weight of isocyanate (isophron diisocyanate), 2 parts by weight of surfactant (1,3-dimethylbutylamine), 2 parts by weight of chain extender (piperazine), 1 part by weight of crosslinking agent (triol), and 12.5 parts by weight of foaming agent (methyl formate and hydrofluoroolefin mixed in a 1:3 ratio by weight) were introduced into a reactor and stirred at a speed of 1800 rpm for 20 minutes to prepare a mixture, the prepared mixture was foamed by stirring at a speed of 6000 rpm for 10 minutes at a temperature of 25°C, and the foamed body was cut into a width of 20 mm × length of 20 mm × thickness of 25 mm to produce a sponge.

[0074] <Comparative Example 2>

[0075] An eco-friendly sponge was manufactured by mixing 20 parts by weight of isocyanate, 1 part by weight of waste raw material, 0.5 parts by weight of surfactant, 0.5 parts by weight of filler, 0.1 parts by weight of flame retardant, 0.5 parts by weight of chain extender, 0.1 parts by weight of crosslinking agent, and 30 parts by weight of foaming agent, in the same manner as in Example 1 above.

[0077] <Comparative Example 3>

[0078] An eco-friendly sponge was manufactured by mixing 80 parts by weight of isocyanate, 20 parts by weight of waste raw material, 5 parts by weight of surfactant, 5 parts by weight of filler, 5 parts by weight of flame retardant, 5 parts by weight of chain extender, 3 parts by weight of crosslinking agent, and 1 part by weight of foaming agent, in the same manner as in Example 1 above.

[0080] The density and tensile strength of the sponges prepared through Examples 1 to 3 and Comparative Examples 1 to 3 were measured and are shown in Table 1 below.

[0081] However, the density of the sponge was measured using the ASTM 3489 method, and

[0082] Tensile strength was measured using a universal resting machine (UTM, Instron Series IX) according to the ASTM 412 method. The measurement conditions were fixed at a sample rate of 10 pts / sec, a crosshead speed of 50 mm / min, and a full scale load range of 50 kgf. Each specimen was measured five times, and the average value was calculated by excluding the minimum and maximum values ​​from the obtained results.

[0083]

[0084]

[0085] As shown in Table 1 above, it can be seen that the sponges produced through Examples 1 to 3 of the present invention have superior tensile strength compared to the sponges produced through Comparative Examples 1 to 2.

[0086] In addition, the sponge produced through Comparative Example 3 had excellent tensile strength, but foaming did not proceed properly, so the cushioning sensation was very low compared to the sponges produced through Examples 1 to 3.

[0088] In addition, the deodorizing effect of the sponges prepared through Example 1 and Comparative Example 1 above was measured and is shown in Table 2 below.

[0089] {However, the deodorizing effect of the sponge was evaluated using the test method of KS I 2218:2008. The sponges prepared through Example 1 and Comparative Example 1 were each cut into 10g pieces, placed into a 5L container containing ammonia, and the change in concentration over time was measured.}

[0090] Table 2

[0091]

[0092] As shown in Table 2 above, it can be seen that the sponge produced through Example 1 of the present invention exhibits a superior deodorizing effect compared to the sponge produced through Comparative Example 1.

[0094] Accordingly, the method for manufacturing an eco-friendly sponge with excellent deodorizing effect according to the present invention provides a sponge that is not only eco-friendly by recycling waste raw materials, but also has excellent deodorizing effect, mechanical properties, and flame retardancy. Explanation of the symbols

[0096] S101 ; Raw material mixing step S103 ; Foaming stage S105 ; Cutting step

Claims

Claim 1 A method for manufacturing an eco-friendly sponge with excellent deodorizing effect, comprising: a raw material mixing step of mixing bio-polyol, isocyanate, waste raw material, surfactant, filler, flame retardant, chain extender, crosslinking agent, and foaming agent; a foaming step of foaming the mixture produced through the raw material mixing step; and a cutting step of cutting the foamed body produced through the foaming step; wherein the waste raw material is composed of one or more selected from the group consisting of waste polyethylene terephthalate and recycled polyol. Claim 2 A method for manufacturing an eco-friendly sponge with excellent deodorizing effect according to claim 1, wherein the raw material mixing step comprises mixing 100 parts by weight of bio-polyol, 40 to 60 parts by weight of isocyanate, 5 to 10 parts by weight of waste raw material, 1 to 3 parts by weight of surfactant, 1 to 3 parts by weight of filler, 0.5 to 1.5 parts by weight of flame retardant, 1 to 3 parts by weight of chain extender, 0.5 to 1.5 parts by weight of crosslinking agent, and 5 to 20 parts by weight of foaming agent. Claim 3 A method for manufacturing an eco-friendly sponge with excellent deodorizing effect, characterized in that, in claim 1 or 2, the bio-polyol is composed of an epoxidized vegetable oil, and the vegetable oil is composed of one or more selected from the group consisting of castor oil, resquarella oil, palm oil, rapeseed oil, sunflower oil, and soybean oil. Claim 4 A method for manufacturing an eco-friendly sponge with excellent deodorizing effect, characterized in that, in claim 1 or 2, the surfactant comprises one or more selected from the group consisting of 1,3-dimethylbutylamine, polydimethylsiloxane, polyoxyalkylene block copolymer, silicate oxide, silicone oil, and nonylphenol ethoxylate. Claim 5 A method for manufacturing an eco-friendly sponge with excellent deodorizing effect, characterized in that, in claim 1 or 2, the filler is composed of one or more selected from the group consisting of expanded vermiculite, maifan stone, zeolite, illite, smectite, and kaolin. Claim 6 A method for manufacturing an eco-friendly sponge with excellent deodorizing effect, characterized in that, in claim 1 or 2, the flame retardant comprises one or more selected from the group consisting of expanded graphite, sodium silicate, potassium hydroxide, aluminum hydroxide, and aluminum oxide. Claim 7 A method for manufacturing an eco-friendly sponge with excellent deodorizing effect, characterized in that, in claim 1 or 2, the chain extender comprises one or more selected from the group consisting of piperazine, diol, and diamine.

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