Method for decomposing polyurethane foam, and method for producing a fluid.

Abstract

This technology provides a way to facilitate the flow of a phase different from the polyol phase in the decomposition products of polyurethane foam. [Solution] A method for decomposing polyurethane foam, comprising decomposing the polyurethane foam with one or more decomposing agents selected from the group consisting of the following compounds (1) and (2), thereby separating it into a first phase containing a polyol and a second phase. Compound (1): A compound having one or more ether groups in its molecular skeleton and amino groups at both ends of its molecular chain. Compound (2): A compound having one or more ether groups in its molecular skeleton, with one end of the molecular chain being an amino group and the other end being a hydroxyl group.

Description

Technical Field

[0001] The present disclosure relates to a method for decomposing polyurethane foam and a method for producing a fluid material.

Background Art

[0002] In order to chemically decompose polyurethane foam and obtain high-purity polyol, it is necessary to separate it into two phases: a polyol phase and an isocyanate-derived phase.

[0003] For example, Patent Document 1 discloses a method in which polyurethane is decomposed using a monoalkanolamine, a high-molecular-weight polyol is extracted and removed with a hydrocarbon solvent, and alkylene oxide is added to the remaining low-molecular-weight decomposition product to regenerate it as a low-molecular-weight polyol.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Since the polyol phase is liquid at room temperature, it can be transported through pipes. In contrast, a phase different from the polyol phase, for example, an isocyanate-derived phase, has fluidity at high temperatures, but easily solidifies when the temperature decreases and easily loses its fluidity. For example, it is conceivable that an amine compound contained in the isocyanate-derived phase solidifies due to a temperature decrease, temperature unevenness, etc. Assuming that the isocyanate-derived phase is transported through pipes, there is a risk of blockage in the pipes due to the solidification of an amine compound or the like. Therefore, it is required to obtain an isocyanate-derived phase that is difficult to solidify as much as possible.

[0006] This disclosure is made in view of the above circumstances and aims to facilitate the flow of a phase different from the polyol phase in the decomposition products of polyurethane foam. This disclosure can be realized in the following forms. [Means for solving the problem]

[0007] The polyurethane foam is decomposed with one or more decomposing agents selected from the group consisting of the following compounds (1) and (2). A method for decomposing polyurethane foam, which separates it into a first phase containing polyol and a second phase. Compound (1): A compound having one or more ether groups in its molecular skeleton and amino groups at both ends of its molecular chain. Compound (2): A compound having one or more ether groups in its molecular skeleton, with one end of the molecular chain being an amino group and the other end being a hydroxyl group. [Effects of the Invention]

[0008] This disclosure provides a technique for facilitating the flow of a phase different from the polyol phase in the decomposition products of polyurethane foam. [Modes for carrying out the invention]

[0009] Herein lies a preferred example of this disclosure. [1] Decompose the polyurethane foam with one or more decomposing agents selected from the group consisting of the following compounds (1) and (2). A method for decomposing polyurethane foam, which separates it into a first phase containing polyol and a second phase. Compound (1): A compound having one or more ether groups in its molecular skeleton and amino groups at both ends of its molecular chain. Compound (2): A compound having one or more ether groups in its molecular skeleton, with one end of the molecular chain being an amino group and the other end being a hydroxyl group. [2] The method for decomposing polyurethane foam according to [1], wherein when the polyurethane foam is 100 parts by mass, 5 parts by mass or more and 75 parts by mass or less of the decomposing agent is used. [3] Decompose the polyurethane foam with one or more decomposing agents selected from the group consisting of the following compounds (1) and (2). The mixture is separated into a first phase containing polyols and a second phase. A method for producing a fluid, comprising obtaining a fluid with a flow temperature of less than 75°C from the second phase. Compound (1): A compound having one or more ether groups in its molecular skeleton and amino groups at both ends of its molecular chain. Compound (2): A compound having one or more ether groups in its molecular skeleton, with one end of the molecular chain being an amino group and the other end being a hydroxyl group. [4] The method for producing a fluid according to [3], wherein when the polyurethane foam is 100 parts by mass, 5 parts by mass or more and 75 parts by mass or less of the decomposing agent is used.

[0010] The disclosure is described in detail below. In this specification, when a numerical range is described using "-", it includes both the lower and upper limits unless otherwise specified. For example, the description "10-20" includes both the lower limit "10" and the upper limit "20". In other words, "10-20" has the same meaning as "10 or more and 20 or less". Furthermore, in this specification, the upper and lower limits of each numerical range can be combined in any way.

[0011] 1. Method for decomposing polyurethane foam The polyurethane foam decomposition method of this disclosure involves decomposing the polyurethane foam with one or more decomposition agents selected from the group consisting of the following compounds (1) and (2), and separating it into a first phase containing a polyol and a second phase. Compound (1): A compound having one or more ether groups in its molecular skeleton and amino groups at both ends of its molecular chain. Compound (2): A compound having one or more ether groups in its molecular skeleton, with one end of the molecular chain being an amino group and the other end being a hydroxyl group.

[0012] Phase 2 is a different phase from Phase 1. Phase 2 may contain amine compounds.

[0013] 1-1. Polyurethane foam The polyurethane foam may be any of rigid polyurethane foam, semi-rigid polyurethane foam, and flexible polyurethane foam. The polyurethane foam can be obtained from a composition for polyurethane foam containing a polyol and an isocyanate. Examples of the polyol include polyether polyol, polymer polyol, polyester polyol, etc. The composition for polyurethane foam may contain, for example, a crosslinking agent, a catalyst, a foam stabilizer, a flame retardant, etc.

[0014] The polyurethane foam can be produced by a known foaming method. The foaming methods include slab foaming and mold foaming, and either molding method may be used. Slab foaming is a method of discharging the mixed composition for polyurethane foam onto a belt conveyor and foaming it under atmospheric pressure at room temperature (for example, 25°C). On the other hand, mold foaming is a method of filling the mixed composition for polyurethane foam into a mold (molding die) and foaming it inside the mold.

[0015] From the perspective of waste reduction, the polyurethane foam is preferably, for example, trim materials discharged during the production process of polyurethane foam, or waste materials of used polyurethane foam to be discarded, etc. The size of the polyurethane foam to be decomposed is not particularly limited. The polyurethane foam such as trim materials and waste materials may be directly decomposed, or may be processed into a predetermined size and then decomposed. For example, from the perspective of ease of decomposition treatment, the polyurethane foam is preferably a pulverized material. Only one kind of polyurethane foam may be used, or two or more kinds may be used.

[0016] 1-2. Decomposing agent The decomposing agent is one or more selected from the group consisting of the following compound (1) and the following compound (2). Compound (1): A compound having one or more ether groups in the molecular skeleton and amino groups at both ends of the molecular chain Compound (2): A compound having one or more ether groups in the molecular skeleton, with an amino group at one end of the molecular chain and a hydroxyl group at the other end

[0017] 1-2-1. Compound (1) Examples of Compound (1) include compounds represented by the following formula [1].

Chem.

[0018] Examples of the compound (1) represented by formula [1] include 2,2′-(ethylenedioxy)bis(ethylamine) represented by the following formula [1a] and polyetheramine D230 represented by the following formula [1b].

Chem.

Chem.

[0019] Examples of Compound (1) include compounds represented by the following formula [2].

Chem.

[0020] Examples of the compound (1) represented by formula [2] include 4,7,10-trioxa-1,13-tridecanediamine (TTDD), represented by the following formula [2a]. [ka]

[0021] Other compounds (1) include 4,9-dioxa-1,12-dodecanediamine, 1,11-diamino-3,6,9-trioxaundecane, 2-(2-aminoethoxy)ethylamine, and 1,14-diamino-3,6,9,12-tetraoxatetra Examples include decane, trimethylolpropane poly(oxypropylene)triamine (JEFFAMINE T-403), glyceryl poly(oxypropylene)triamine (JEFFAMINE T-3000, T-5000), polyetheramine (JEFFAMINE D-400, D-2000, D-2010, D-4000), polyetheramine (JEFFAMINE ED-600, ED-900, ED-2003), and polyetheramine (JEFFAMINE RT-1000).

[0022] 1-2-1. Compound (2) Examples of compound (2) include the compound represented by the following formula [3]. [ka] In equation [3], R 1 ,R 2 Each represents either a hydrogen atom or a methyl group. p represents an integer between 1 and 50.

[0023] Examples of the compound (2) represented by formula [3] include diethylene glycolamine (DGA) represented by the following formula [3a]. [ka]

[0024] Other examples of compound (2) include triethylene glycolamine and 1-amino-3,6,9-trioxaundecanyloyl-11-ol.

[0025] The amount of decomposing agent added to the polyurethane foam is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and even more preferably 15 parts by mass or more, when the polyurethane foam is 100 parts by mass, from the viewpoint of separating it into a first phase and a second phase and suppressing the solidification of the second phase. The amount of the above-mentioned decomposing agent added is preferably 75 parts by mass or less, more preferably 50 parts by mass or less, and even more preferably 25 parts by mass or less, when the polyurethane foam is 100 parts by mass, from the viewpoint of suppressing the reaction product from being only one phase. From these viewpoints, the amount of the above-mentioned decomposing agent added is preferably 5 parts by mass or more and 75 parts by mass or less, more preferably 10 parts by mass or more and 50 parts by mass or less, and even more preferably 15 parts by mass or more and 25 parts by mass or less, when the polyurethane foam is 100 parts by mass.

[0026] 1-3. Other ingredients In a method for decomposing polyurethane foam, components other than polyurethane foam and decomposing agents (also referred to as other components) may be used. From the viewpoint of reusing reaction products, it is preferable not to use other components. Examples of other components include decomposition catalysts (tertiary amines, metal salts, etc.), nonamine polyols such as glycols, metal hydroxides, and water.

[0027] In a method for decomposing polyurethane foam, the reaction rate can be increased by using a decomposition catalyst. Preferably, the decomposition catalyst is one included in a polyurethane foam composition.

[0028] As a decomposition catalyst for tertiary amines, tertiary amines that do not have hydroxyl groups are preferred. Examples of tertiary amine decomposition catalysts include diazabicycloundecene, triethylamine, tripropylamine, tributylamine, hexadecyldimethylamine, N-methylmorpholine, N-ethylmorpholine, N-octadecylmorpholine, diethyltriamine, N,N,N',N'-tetramethylhexanediamine, N,N,N',N'-tetramethylpropanediamine, N,N,N',N'',N''-pentamethyldiethylenetriamine, N,N',N'-trimethylaminoethylpiperazine, N,N-dimethylcyclohexylamine, N,N,N',N'-tetramethylethylenediamine, and 1,4-diazabicyclo[2.2.2]octane.

[0029] As a decomposition catalyst for metal salts, one that can be used in combination with a decomposition catalyst for tertiary amines is preferred. Examples of metal salt decomposition catalysts include stanus octoate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin marker captide, dibutyltin thiocarboxylate, dibutyltin dimaleate, dioctyltin marker captide, dioctyltin thiocarboxylate, lead octoate, potassium acetate, potassium octoate, and the like.

[0030] The amount of decomposition catalyst added to the polyurethane foam is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and even more preferably 0.8 parts by mass or more, when the polyurethane foam is 100 parts by mass, from the viewpoint of increasing the reaction rate in the decomposition process. The amount of the above-mentioned decomposition agent added is preferably 5 parts by mass or less, more preferably 3 parts by mass or less, and even more preferably 1.5 parts by mass or less, when the polyurethane foam is 100 parts by mass, from the viewpoint of making it easier to reuse the reaction products (from the viewpoint of suppressing side reactions, from the viewpoint of suppressing the residue of the decomposition catalyst in the recycled polyol phase (first phase), and from the viewpoint of reducing material costs). From these viewpoints, the amount of the above-mentioned decomposition agent added is preferably 0.1 parts by mass or more and 5 parts by mass or less, more preferably 0.5 parts by mass or more and 3 parts by mass or less, and even more preferably 0.8 parts by mass or more and 1.5 parts by mass or less, when the polyurethane foam is 100 parts by mass.

[0031] 1-4. Decomposition conditions The conditions for decomposing polyurethane foam are not particularly limited, as long as the polyurethane foam can be decomposed by a decomposing agent.

[0032] From the perspective of improving the decomposition rate, a good method for decomposing polyurethane foam is to heat the polyurethane foam together with a decomposition agent. When heating the polyurethane foam together with the decomposition agent, it is good to stir the mixture of polyurethane foam and decomposition agent.

[0033] The heating temperature is preferably 80°C to 300°C, more preferably 100°C to 270°C, and even more preferably 150°C to 250°C, in order to improve the decomposition rate while suppressing the decomposition of the polyol as a reaction product, i.e., the polyol that formed the polyurethane foam.

[0034] The reaction time may be, for example, 10 minutes to 10 hours, or 30 minutes to 6 hours. The endpoint of the reaction may be set appropriately while checking the progress of the decomposition of the polyurethane foam, depending on the size of the polyurethane foam, whether or not stirring is performed, etc.

[0035] 1-5. Phase state after disassembly Polyurethane foam is separated into a first phase and a second phase by decomposition treatment. The first phase mainly contains polyols. The second phase is isocyanate-derived and mainly contains amine compounds. The second phase may also contain urea compounds.

[0036] It is preferable to obtain a fluid (reaction product) with a flow temperature (pour point) of less than 75°C from the second phase. The flow temperature is the lowest temperature at which a fluid state (a state in which fluidity is maintained) can be maintained. A fluid state is a state in which the viscosity is 10 mPa·s or more and 100,000 mPa·s or less (a state including liquid and paste-like states). "Obtaining a fluid with a flow temperature of less than 75°C from the second phase" includes obtaining the entire second phase as a fluid with a flow temperature of less than 75°C, and obtaining a fluid with a flow temperature of less than 75°C from a part of the second phase.

[0037] From the viewpoint of facilitating transport, the flow temperature (pour point) of the second phase is preferably less than 75°C, more preferably 70°C or less, and even more preferably 65°C or less. In particular, it is preferable that the flow temperature of the second phase is below room temperature (25°C) (i.e., that it is fluid at room temperature (25°C)). "Fluids with a flow temperature (pour point) below 75°C" may include those that are solid at room temperature (25°C).

[0038] Here, the flow temperature of the second phase is defined as follows: After placing the second phase (10g) of the polyurethane foam decomposition product as a sample on an aluminum plate, a 50g stainless steel weight (shape: cylindrical, diameter 10mm) is placed on top of the sample. This aluminum plate is placed on a hot plate and heated. The temperature of the sample is measured during heating, and the temperature at the moment the weight sinks is defined as the flow temperature (pour point).

[0039] By decomposing polyurethane foam with a decomposition agent containing amino groups, the urethane bonds formed by the polyol and isocyanate undergo an exchange reaction with the amino groups contained in the decomposition agent to generate urea bond groups that are more rigid than the urethane bonds. If a compound simply containing amino groups is used as the decomposition agent, it is thought that aggregation will occur due to intermolecular interactions between the rigid urea bond groups, and therefore it will not flow unless heated to a high temperature. However, by using the above-mentioned decomposition agent (a compound having an ether group in its molecular skeleton) of this disclosure, it is thought that a flexible ether group is introduced into the structure of the condensate formed by the exchange reaction with the urethane bonds in the polyurethane foam. As a result, a soft isocyanate-derived phase (second phase) is generated, which is thought to allow it to flow without aggregation even at low temperatures.

[0040] 2. Method for manufacturing fluids The present disclosure is a method for producing a fluid, in which polyurethane foam is decomposed with one or more decomposing agents selected from the group consisting of the following compounds (1) and (2), separated into a first phase containing a polyol and a second phase, and a fluid with a flow temperature of less than 75°C is obtained from the second phase. Compound (1): A compound having one or more ether groups in its molecular skeleton and amino groups at both ends of its molecular chain. Compound (2): A compound having one or more ether groups in its molecular skeleton, with one end of the molecular chain being an amino group and the other end being a hydroxyl group.

[0041] "Obtaining a fluid with a flow temperature of less than 75°C from the second phase" includes obtaining the entire second phase as a fluid with a flow temperature of less than 75°C, and obtaining a fluid with a flow temperature of less than 75°C from a portion of the second phase.

[0042] In the manufacturing method of the fluid, the explanations in the section on "Method for Decomposing Polyurethane Foam" will be applied as is, and the descriptions will be omitted for "polyurethane foam," "decomposition agent," "other components (components other than the decomposition agent)," "decomposition conditions," and "phase state after decomposition treatment."

[0043] 4. Effects By using one or more decomposition agents (compounds having ether groups in their molecular skeleton) selected from the group consisting of compound (1) and compound (2) of this disclosure, an exchange reaction occurs between the urethane bonds or urea bonds of the material to be decomposed (polyurethane foam) and the amino groups or hydroxyl groups of the decomposition agent. As a result, polyols are released, and a condensate is formed by an exchange reaction between the decomposition agent and the urethane bonds in the polyurethane foam. Since a flexible ether group is introduced into the structure of the condensate, the reaction products of the isocyanate-derived phase (second phase) can be flowed without agglomerating even at relatively low temperatures (below 75°C). Therefore, when transporting the isocyanate-derived phase through piping, clogging of the piping due to solidification of amine compounds, etc., can be prevented. [Examples]

[0044] 1. Manufacturing of polyurethane foam Polyurethane foam compositions (liquid A and liquid B) were prepared using the proportions shown in Table 1 for "polyurethane foam," and polyurethane foam (degradable polyurethane foam) was produced by slab foaming.

[0045] Details of each ingredient are as follows: <Decomposable polyurethane foam 1 (also referred to as decomposable urethane 1)> • Polyol: Polyether polyol, number average molecular weight 3000, number of functional groups 3, hydroxyl value 56.1 mgKOH / g, product name: Sannix GP-3050NS, manufactured by Sanyo Chemical Industries, Ltd. • Amine catalyst: Product name: DABCO 33LSI, manufactured by EVONIK. • Foam stabilizer: Silicone foam stabilizer, product name: Niax silicone L-595, manufactured by Momentive. • Tin catalyst: Stannous octylate, Product name: MRH-110, Manufactured by Johoku Chemical Industry Co., Ltd. • Foaming agent: Water • Isocyanate: Tolylene diisocyanate, product name Coronate T-80, manufactured by Tosoh Corporation, NCO%: 48.2% <Decomposable Polyurethane Foam 2 (also referred to as Decomposable Urethane 2)> • Polyol: Polyether polyol, number average molecular weight 3000, number of functional groups 3, hydroxyl value 56.1 mgKOH / g, product name: Sannix GP-3050NS, manufactured by Sanyo Chemical Industries, Ltd. • Polymer polyol: Acrylonitrile-styrene graft polymer polyol, Product name: AGC Corporation's Exenol 941 • Amine catalyst: Product name: DABCO 33LSI, manufactured by EVONIK. • Foam stabilizer: Silicone foam stabilizer, product name: L-595, manufactured by Momentive. • Tin catalyst: Stannous octylate, Product name: MRH-110, Manufactured by Johoku Chemical Industry Co., Ltd. • Foaming agent: Water • Isocyanate: Tolylene diisocyanate, product name Coronate T-80, manufactured by Tosoh Corporation, NCO%: 48.2%

[0046] [Table 1]

[0047] 2. Decomposition treatment of polyurethane foam An experiment was conducted to decompose polyurethane foam (polyurethane foam to be decomposed) using a decomposition agent. In addition to the decomposition agent, a decomposition catalyst was added to the polyurethane foam. Details of the decomposition agent and catalyst are as follows. • Decomposition agent 1: Diethylene glycolamine (DGA) represented by the above formula [3a], molecular weight 105.14, manufactured by Tokyo Chemical Industry Co., Ltd. • Decomposition agent 2: 2,2′-(ethylenedioxy)bis(ethylamine) (EDEA), represented by the above formula [1a], molecular weight 148.20, manufactured by Sigma-Aldrich. • Decomposition agent 3: Polyetheramine D230, molecular weight 230, represented by the above formula [1b], manufactured by BASF. • Decomposition agent 4: 4,7,10-trioxa-1,13-tridecanediamine (TTDD), represented by [2a] above, molecular weight 220.31, manufactured by Sigma-Aldrich. • Decomposition agent 5: 3,3'-diamino-N-methyldipropylamine (BAPMA), molecular weight 145.25, manufactured by Tokyo Chemical Industry Co., Ltd. • Decomposition agent: 6:3-butoxypropanolamine (BPA), molecular weight 131.22, manufactured by Tokyo Chemical Industry Co., Ltd. • Decomposition catalyst: Diazabicycloundecene (DBU), manufactured by Tokyo Chemical Industry Co., Ltd.

[0048] In Examples 1-9 and Comparative Example 1-4, 100 g of polyurethane foam (polyurethane foam to be decomposed) and a decomposition agent in the proportions shown in Table 2 below were placed in a 1 L separable flask. The mixture of polyurethane foam and decomposition agent was heated at 200°C for 6 hours with stirring to obtain polyurethane foam decomposition products. When the obtained polyurethane foam decomposition products consisted of a liquid phase (upper phase, polyol phase) and a solid phase (lower phase, isocyanate-derived phase), the solid and liquid phases were separated using a #40 stainless steel mesh. When the two phases (upper and lower phases) became liquid, the upper and lower phases were separated using a separatory funnel or the like. Here, the upper phase (polyol phase) corresponds to the "first phase," and the lower phase (isocyanate-derived phase) corresponds to the "second phase."

[0049] [Table 2]

[0050] [Table 3]

[0051] 3. Evaluation Method 3-1. Phase state after decomposition The phase state of polyurethane foam after decomposition (phase state of polyurethane foam decomposition products) in Examples 1-9 and Comparative Examples 1-4 was evaluated according to the following criteria. The results are shown in Tables 2 and 3. "A": Separation of the two phases (upper phase, lower phase) can be confirmed visually. "B": Visual separation of the two phases (upper phase, lower phase) cannot be confirmed (only one phase can be confirmed).

[0052] 3-2. Recovery rate of the upper phase (polyol phase) (liquid phase recovery rate) The recovery rate of the upper phase (polyol phase) in Examples 1-9 and Comparative Example 1-4 (liquid phase recovery rate) was evaluated according to the following criteria. The liquid phase recovery rate was determined by measuring the mass ratio (%) of the upper phase (polyol phase) to the mass of the polyurethane foam decomposition product. The results are shown in Tables 2 and 3. "A": Liquid phase recovery rate is 30% to 70%. "B": Liquid phase recovery rate is less than 30% or greater than 70%.

[0053] 3-3. Flow temperature of the lower phase (isocyanate-derived phase) The flow temperature of the lower phase (isocyanate-derived phase) in Examples 1-9 and Comparative Example 1-4 was evaluated according to the following criteria. The flow temperature of the lower phase (isocyanate-derived phase) was determined as follows: After placing the lower phase (isocyanate-derived phase) of each polyurethane foam decomposition product in Examples 1-9 and Comparative Example 1-4 as a sample on an aluminum plate, a 50g stainless steel weight (shape: cylindrical, diameter: 10mm) was placed on top of the sample. This aluminum plate was placed on a hot plate and heated. The temperature of the sample was measured during heating, and the temperature at the moment the weight sank was defined as the flow temperature (pour point). The results are shown in Tables 2 and 3. In Tables 2 and 3, room temperature is 25°C. Note that in Table 3, the "*" in the "Flow temperature of the lower phase (isocyanate-derived phase)" column for Comparative Example 4 indicates that the flow temperature could not be measured at temperatures above 150°C. "A": The flow temperature of the lower phase (isocyanate-derived phase) is less than 75°C. "B": The flow temperature of the lower phase (isocyanate-derived phase) is 75°C or higher, or measurement is not possible.

[0054] 3-4. Overall Judgment The overall evaluations for Examples 1-9 and Comparative Examples 1-4 are shown together in Tables 2 and 3. "A": The evaluation of all aspects, including the phase state after decomposition, the recovery rate of the upper phase (polyol phase) (liquid phase recovery rate), and the flow temperature of the lower phase (isocyanate-derived phase), is "A". "B": At least one of the following evaluations is "B": Phase state after decomposition, recovery rate of the upper phase (polyol phase) (liquid phase recovery rate), and flow temperature of the lower phase (isocyanate-derived phase).

[0055] 4. Evaluation Results In Examples 1-9, all evaluations, including the phase state after decomposition, the recovery rate of the upper phase (polyol phase) (liquid phase recovery rate), and the flow temperature of the lower phase (isocyanate-derived phase), were "A". That is, in Examples 1-9, the polyurethane foam decomposition product separated into two phases (upper phase and lower phase), sufficient upper phase (polyol phase) was recovered, and the flow temperature of the lower phase (isocyanate-derived phase) was relatively low (less than 75°C). In Examples 1-3, 8, and 9, a compound having one or more ether groups in the molecular skeleton and amino groups at both ends of the molecular chain (compound (1) above) was used as the decomposition agent, while in Examples 4-7, a compound having one or more ether groups in the molecular skeleton and an amino group at one end of the molecular chain and a hydroxyl group at the other end (compound (2) above) was used as the decomposition agent.

[0056] On the other hand, in Comparative Examples 2 and 4, the evaluation of the phase state after decomposition and the recovery rate of the upper phase (polyol phase) (liquid phase recovery rate) was "A", while the evaluation of the flow temperature of the lower phase (isocyanate-derived phase) was "B". In other words, in Comparative Examples 2 and 4, although the polyurethane foam decomposition product separated into two phases (upper phase and lower phase), the flow temperature of the lower phase (isocyanate-derived phase) was relatively high (75°C or higher). In Comparative Example 3, the evaluation of the phase state after decomposition was "B" from the start, and the upper phase (polyol phase) could not be recovered. In Comparative Examples 2-4, the above compounds (1) and (2) were not used as decomposition agents.

[0057] As described above, in Examples 1-9, by using compounds (1) and (2) as decomposition agents, an exchange reaction occurs between the urethane or urea bonds of the material to be decomposed (polyurethane foam) and the amino or hydroxyl groups of the decomposition agent. As a result, polyols are liberated, and a condensate of the decomposition agent and the isocyanate-derived compound is formed. Since a flexible ether group is introduced into the structure of this condensate, the reaction product of the lower phase (isocyanate-derived phase) can be flowed without agglomerating even at relatively low temperatures (below 75°C).

[0058] In Examples 1-7, decomposition treatment was performed on decomposition agents (compounds (1) and (2) above) on polyurethane foam 1, which was manufactured using only polyether polyol as the polyol. On the other hand, in Examples 8 and 9, decomposition treatment was performed on decomposition agents (compounds (1) and (2) above) on polyurethane foam 2, which was manufactured using polymer polyol in addition to polyether polyol as the polyol. In both Examples 1-7 and Examples 8 and 9, the evaluation of the phase state after decomposition, the recovery rate of the upper phase (polyol phase) (liquid phase recovery rate), and the flow temperature of the lower phase (isocyanate-derived phase) was all "A". This shows that for both decomposition polyurethane foams 1 and 2, using the decomposition agents (compounds (1) and (2) above) yields polyurethane foam decomposition products with a relatively low flow temperature (less than 75°C) in the lower phase. Products using polymer polyols include mattresses, and it is expected from the data of Examples 1 and 9 that such products can be decomposed (recycled), which is useful from the perspective of SDGs (Sustainable Development Goals).

[0059] In Examples 1-3, 15-50 parts by mass of the decomposition agent (diethylene glycolamine (DGA), compound (1)) was used when the polyurethane foam was 100 parts by mass. On the other hand, in Comparative Example 1, 100 parts by mass of the decomposition agent (diethylene glycolamine (DGA), compound (1)) was used when the polyurethane foam was 100 parts by mass. In Comparative Example 1, the evaluation of the phase state after decomposition was "B", and the upper phase (polyol phase) could not be recovered. It was found that the polyurethane foam decomposition product could not be separated into two phases (upper phase and lower phase) due to the addition of too much decomposition agent. This is thought to be because the decomposition agent acted as a compatibilizer due to the addition of too much, mixing the upper phase (polyol phase) and the lower phase (isocyanate-derived phase).

[0060] 5. Effects of the Examples According to this embodiment, by using one or more decomposition agents (compounds having an ether group in their molecular skeleton) selected from the group consisting of compound (1) and compound (2) above, the isocyanate-derived phase could be made to flow without condensation even at low temperatures (e.g., 25°C). Therefore, when transporting the isocyanate-derived phase through piping, clogging of the piping can be prevented.

[0061] This disclosure is not limited to the embodiments detailed above, and various modifications or changes are possible within the scope of this disclosure.

Claims

1. The polyurethane foam is decomposed with one or more decomposing agents selected from the group consisting of the following compounds (1) and (2). A method for decomposing polyurethane foam, which separates it into a first phase containing a polyol and a second phase. Compound (1): A compound having one or more ether groups in its molecular skeleton and amino groups at both ends of its molecular chain. Compound (2): A compound having one or more ether groups in its molecular skeleton, with one end of the molecular chain being an amino group and the other end being a hydroxyl group.

2. The method for decomposing polyurethane foam according to claim 1, wherein when the polyurethane foam is 100 parts by mass, 5 parts by mass or more and 75 parts by mass or less of the decomposing agent is used.

3. The polyurethane foam is decomposed with one or more decomposing agents selected from the group consisting of the following compounds (1) and (2). The mixture is separated into a first phase containing polyols and a second phase. A method for producing a fluid, comprising obtaining a fluid with a flow temperature of less than 75°C from the second phase. Compound (1): A compound having one or more ether groups in its molecular skeleton and amino groups at both ends of its molecular chain. Compound (2): A compound having one or more ether groups in its molecular skeleton, with one end of the molecular chain being an amino group and the other end being a hydroxyl group.

4. The method for producing a fluid according to claim 3, wherein when the polyurethane foam is 100 parts by mass, the decomposing agent is used in an amount of 5 parts by mass or more and 75 parts by mass or less.

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