Composition for polyurethane decomposition, polyurethane decomposition product, method for producing polyurethane decomposition product, and method for decomposing polyurethane resin

Abstract

To provide a technique for obtaining a polyurethane decomposition product.SOLUTION: A composition for polyurethane decomposition contains a decomposer and a catalyst, wherein the decomposer is an amino alcohol that does not have a primary amino group or a secondary amino group, and the catalyst is a tertiary amine compound that does not have a hydroxyl group.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to a composition for decomposing polyurethanes, a polyurethane decomposition product, a method for producing a polyurethane decomposition product, and a method for decomposing a polyurethane resin. [Background technology]

[0002] Polyurethane foam is used in various fields. Attempts have been made to chemically decompose and reuse polyurethane foam scraps, used polyurethane foam, etc.

[0003] Patent Document 1 describes a method for producing recycled polyether polyol. The method for producing recycled polyether polyol in Patent Document 1 includes a step of adding rigid polyurethane foam to a mixture of a composition for decomposing rigid polyurethane foam containing a specific polyol, a metal hydroxide, and water.

[0004] Patent Document 2 describes a method for liquefying a polyurethane molded product. In the method for liquefying a polyurethane molded product described in Patent Document 2, the polyurethane molded product is decomposed by an isocyanate component having an NCO group in an amount 5 times or more equivalent to the OH group (excluding water) required for the production of the polyurethane molded product.

[0005] Patent Document 3 describes a method for treating soft urethane resin-containing waste. In the method for treating soft urethane resin-containing waste in Patent Document 3, a decomposition agent is added to the soft urethane resin-containing waste to initiate a decomposition reaction, and the decomposition reaction is stopped when the concentration of diamine derived from isocyanate in the soft urethane resin raw material is 2 wt% or less to obtain a paste-like intermediate product. The intermediate product is then reheated to obtain a final decomposition product. It is described that the final decomposition product is in a two-phase separated form.

[0006] Patent Document 4 describes a method for producing a recycled polyether polyol. In the method for producing a recycled polyether polyol in Patent Document 4, flexible polyurethane foam scraps are thermally decomposed in a mixture of polyol and metal hydroxide in the presence of water, and then the remaining water in the decomposition liquid is removed, and an alkylene oxide is addition-polymerized to the decomposition liquid to obtain a homogeneous recycled polyether polyol. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2000-109540 A [Patent Document 2] Japanese Patent Application Publication No. 05-222152 [Patent Document 3] JP 2005-015526 A [Patent Document 4] Japanese Patent Application Publication No. 07-224141 Summary of the Invention [Problem to be solved by the invention]

[0008] The technology of Patent Document 1 has concerns that the added water or metal hydroxides may affect the use of recycled polyether polyol. The technology of Patent Document 2 obtains polyurethane decomposition products as components containing isocyanate groups, and there are concerns about the storage stability of the raw material. The technology of Patent Document 3 produces a paste-like single liquid to reduce the volume, but the final decomposition product is in a two-phase separated form. Therefore, in order to use the final decomposition product as a recycled raw material, it is time-consuming to separate the liquid and solid. The technology of Patent Document 4 involves addition polymerization of alkylene oxide, which makes the process complicated and requires special equipment.

[0009] The present disclosure has been made in consideration of the above circumstances, and aims to solve at least one of the above problems. The present disclosure can be realized in the following aspects. [Means for solving the problem]

[0010] [1] A composition for decomposing polyurethanes, comprising a decomposing agent and a catalyst, The decomposition agent is an amino alcohol having no primary amino group or no secondary amino group, The composition for decomposing polyurethane, wherein the catalyst is a tertiary amine compound having no hydroxyl group. Effect of the Invention

[0011] According to the present disclosure, at least one of the above problems can be solved. For example, it is possible to provide a technique for easily obtaining a polyurethane decomposition product that can be easily used as a recycled urethane raw material. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Here, a preferred example of the present disclosure is given. [2] The composition for decomposing polyurethane according to [1], further comprising a polyol. [3] A polyurethane decomposition product obtained by decomposing a polyurethane resin using the polyurethane decomposition composition described in [1] or [2]. [4] A method for producing a polyurethane decomposition product, comprising decomposing a polyurethane resin using the polyurethane decomposition composition according to [1] or [2]. [5] A method for decomposing a polyurethane resin, comprising decomposing the polyurethane resin using the polyurethane decomposition composition according to [1] or [2].

[0013] The present disclosure will be described in detail below. In this specification, when a numerical range is described using "-", the lower limit and the upper limit are included 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". In this specification, the upper limit and the lower limit of each numerical range can be arbitrarily combined.

[0014] 1.Polyurethane decomposition composition The polyurethane decomposition composition contains a decomposing agent and a catalyst. The decomposing agent is an amino alcohol having no primary amino group or secondary amino group. The catalyst is a tertiary amine compound having no hydroxyl group.

[0015] (1) Polyurethane resin The polyurethane decomposition composition is used for decomposing a polyurethane resin. The polyurethane resin is not particularly limited. The polyurethane resin is, for example, a polyurethane foam. The polyurethane foam may be any of a flexible polyurethane foam, a semi-rigid polyurethane foam, and a rigid polyurethane foam. The polyurethane foam may be a polyurethane foam having an open cell structure, or a polyurethane foam having a closed cell structure. The polyurethane foam may be a pulverized material pulverized to a predetermined size. The polyurethane foam may also be a cut material cut to a predetermined size. The polyurethane foam may be, for example, a scrap material discharged in the manufacturing process of the polyurethane foam, or a used polyurethane foam to be discarded.

[0016] The polyurethane decomposition composition is also suitable for decomposing polyurethane resin obtained from a composition containing a polymer polyol, since it can reduce the solid content in the polyurethane decomposition product. The content of the polymer content of the polymer polyol is not particularly limited. The content of the polymer content of the polymer polyol may be 10% by mass or more, 20% by mass or more, 30% by mass or more, or 35% by mass or more, when the total polymer polyol is taken as 100% by mass. The content of the polymer content of the above polymer polyol may be 50% by mass or less, or 45% by mass or less.

[0017] The polyurethane decomposition composition is also suitable for decomposing a polyurethane resin obtained from a composition containing a flame retardant, since it can reduce the solid content in the polyurethane decomposition product. The flame retardant is not particularly limited. The flame retardant is, for example, a phosphorus-based flame retardant such as a phosphate ester-based flame retardant. The phosphate ester-based flame retardant may be a halogenated phosphate ester-based flame retardant containing a halogen. The content of the flame retardant is not particularly limited. The content of the flame retardant may be, for example, 5 parts by mass or more and 30 parts by mass or less, or 10 parts by mass or more and 25 parts by mass or less, when the polyol contained in the composition is 100 parts by mass.

[0018] (2) Decomposition agent The decomposing agent is an amino alcohol having no primary amino group and no secondary amino group. The amino alcohol of the present disclosure can suitably suppress phase separation of the polyurethane decomposition product. Although the reason is unclear, it is speculated that the amino alcohol having no primary amino group and no secondary amino group is less likely to react with the decomposition product than the amino alcohol having a primary amino group or a secondary amino group, which contributes to suppression of phase separation. In addition, it is considered that the above amino alcohol has an effect of making the polyol and the amine component contained in the polyurethane decomposition product of the polyurethane resin compatible. Note that the present disclosure is not limited to this speculation.

[0019] The amino alcohol of the present disclosure has at least one tertiary amino group and at least one hydroxyl group in the molecule as functional groups other than the hydrocarbon group. The amino alcohol is preferably a hydrocarbon group having a total carbon number of 2 to 10 and a hydroxyl group attached to a nitrogen atom, the hydrocarbon group optionally being interrupted by an ether group. The number of tertiary amino groups in the amino alcohol is not particularly limited, and is preferably 1 to 4, more preferably 1 to 3. The number of hydroxyl groups in the amino alcohol is not particularly limited, and is preferably 1 to 4, more preferably 1 to 3. The molecular weight of the amino alcohol is not particularly limited. The molecular weight of the amino alcohol is preferably 800 or less, more preferably 600 or less, and even more preferably 450 or less. The lower limit is not particularly limited, but is, for example, 80 or more.

[0020] The amino alcohol is, for example, triethanolamine, N-phenyldiethanolamine, N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine, N,N-dimethylaminohexanol, N-methyldiethanolamine, 2-dimethylaminoethanol, 1,1',1''-nitrilotri-2-propanol, Nn-butyl-2,2'-iminodiethanol, 2-[2-(dimethylamino)ethoxy]ethanol, 2-[[2-(dimethylamino)ethyl]methylamino]ethanol, 2-morpholinoethanol, 2-hydroxymethyl-4-benzylmorpholine, N-(2-hydroxypropyl)morpholine, 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol, 2-(4-methyl-2-phenyl-1-piperazinyl)-3-pyridinemethanol, and 1-piperidineethanol. At least one selected from the group consisting of these is preferred. Among these, at least one selected from the group consisting of triethanolamine, N-phenyldiethanolamine, N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine, and N,N-dimethylaminohexanol is more preferred. Only one amino alcohol may be used, or two or more amino alcohols may be used in combination.

[0021] The amount of amino alcohol added is not particularly limited. From the viewpoint of sufficiently decomposing the polyurethane resin, the amount of amino alcohol added is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and even more preferably 8 parts by mass or more, relative to 100 parts by mass of polyurethane resin. In consideration of the effect on reactivity and physical properties when the polyurethane resin decomposition product is reused as a polyurethane resin raw material, etc., the amount of the amino alcohol added is preferably 100 parts by mass or less, more preferably 75 parts by mass or less, and even more preferably 50 parts by mass or less. From these viewpoints, the amount of the amino alcohol added is preferably 1 part by mass or more and 100 parts by mass or less, more preferably 5 parts by mass or more and 75 parts by mass or less, and even more preferably 8 parts by mass or more and 50 parts by mass or less. The decomposition agent may be a combination of the amino alcohol and another decomposition agent.

[0022] (3) Catalyst The catalyst is a tertiary amine compound that does not have a hydroxyl group. The tertiary amine compound of the present disclosure can suitably suppress phase separation of polyurethane decomposition products. Although the reason is unclear, it is speculated that the tertiary amine compound is less likely to react with decomposition products than an amine compound having a primary amino group or a secondary amino group, which contributes to suppression of phase separation. Note that the present disclosure is not limited to this speculation.

[0023] The tertiary amine compound of the present disclosure has at least one tertiary amino group in the molecule as a functional group other than a hydrocarbon group. The number of tertiary amino groups in the tertiary amine compound is not particularly limited. The number of the tertiary amino groups is preferably 1 to 4, more preferably 1 to 3. The molecular weight of the tertiary amine compound is not particularly limited. The molecular weight of the tertiary amine compound is preferably 600 or less, more preferably 400 or less, and even more preferably 200 or less. The lower limit is not particularly limited, but is, for example, 60 or more.

[0024] The tertiary amine compound is preferably one or more selected from the group consisting of, for example, diazabicycloundecene, triethylamine, tripropylamine, tributylamine, hexadecyldimethylamine, N-methylmorpholine, N-ethylmorpholine, N-octadecylmorpholine, 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. Only one type of tertiary amine compound may be used, or two or more types may be used in combination.

[0025] The amount of the tertiary amine compound added is not particularly limited. From the viewpoint of sufficiently decomposing the polyurethane resin, the amount of the tertiary amine compound added is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, and even more preferably 0.3 parts by mass or more, relative to 100 parts by mass of the polyurethane resin. The amount of the tertiary amine compound added is preferably 8 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 3 parts by mass or less, taking into consideration the effect on reactivity and physical properties when the polyurethane resin decomposition product is reused as a polyurethane resin raw material, etc. From these viewpoints, the amount of the tertiary amine compound added is preferably 0.05 parts by mass or more and 8 parts by mass or less, more preferably 0.1 parts by mass or more and 5 parts by mass or less, and even more preferably 0.3 parts by mass or more and 3 parts by mass or less.

[0026] The catalyst may be a combination of the above-mentioned tertiary amine compound and another catalyst. The other catalyst is preferably at least one selected from the group consisting of stannous octoate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin mercaptide, dibutyltin thiocarboxylate, dibutyltin dimaleate, dioctyltin mercaptide, dioctyltin thiocarboxylate, lead octylate, potassium acetate, and potassium octylate.

[0027] (4) Other ingredients The polyurethane decomposition composition may further contain components other than the decomposing agent and the catalyst (also referred to as other components). For example, from the viewpoint of obtaining a one-phase polyurethane decomposition product, the polyurethane decomposition composition preferably further contains a polyol (excluding amino alcohols). The polyol may be, for example, a low molecular weight polyol having a number average molecular weight of less than 1000, or a high molecular weight polyol having a number average molecular weight of 1000 or more, and these may be used in combination.

[0028] Examples of the low molecular weight polyol include trihydric alcohols such as glycerin and trimethylolpropane, and dihydric alcohols such as ethylene glycol, propylene glycol, 1,3-propanediol, diethylene glycol, triethylene glycol, and dipropylene glycol. Examples of the low molecular weight polyol include polyether polyols, polyester polyols, and polyether ester polyols having a number average molecular weight of less than 1000.

[0029] The high molecular weight polyol is preferably at least one selected from polyether polyols, polyester polyols, and polyether ester polyols having a number average molecular weight of 1000 or more. The high molecular weight polyol may be a raw material polyol for a recycled polyurethane resin using a polyurethane decomposition product described below. By using the raw material polyol for a recycled polyurethane resin, the influence of the components in the polyurethane decomposition composition on the production of a recycled polyurethane resin can be reduced.

[0030] The amount of polyol added is not particularly limited. The amount of polyol added is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and even more preferably 8 parts by mass or more, relative to 100 parts by mass of polyurethane resin, from the viewpoint of obtaining a one-phase polyurethane decomposition product. When using a raw material polyol for recycled polyurethane resin, the amount of polyol added may be 10 parts by mass or more, 25 parts by mass or more, or 30 parts by mass or more, from the viewpoint of obtaining a polyurethane decomposition product with low viscosity. The amount of polyol added is usually 200 parts by mass or less, and may be 100 parts by mass or less, 50 parts by mass or less, 30 parts by mass or less, or 20 parts by mass or less. The amount of polyol added is preferably 1 part by mass or more and 200 parts by mass or less, and may be a range that appropriately combines the upper limit value and the lower limit value.

[0031] 2. Polyurethane decomposition products The polyurethane decomposition product can be obtained by decomposing a polyurethane resin with the above-mentioned polyurethane decomposition composition.

[0032] The polyurethane decomposition product includes, for example, a polyol derived from the raw material polyol of the polyurethane resin, and an amine component derived from the raw material isocyanate. In addition, the polyurethane decomposition product may include a flame retardant, a catalyst, and other additives contained in the polyurethane resin.

[0033] The state of the polyurethane decomposition product is not particularly limited. The polyurethane decomposition product is preferably obtained as a one-phase liquid. In the present disclosure, the "one-phase liquid" refers to a liquid that is not evaluated as "C: clearly separated" for "phase separation" in the examples described later. The one-phase liquid contains, for example, a polyol derived from the raw material polyol and an amine component derived from the raw material isocyanate in a compatible state. The one-phase liquid may contain solid content. That is, the one-phase liquid may be evaluated as "B: solid content can be confirmed, but not clearly separated" for "phase separation" in the examples described later. The solid content is, for example, a component derived from a polymer polyol containing a polymer such as styrene or acrylonitrile, or a flame retardant such as a phosphorus-based flame retardant or a halogen-based flame retardant.

[0034] In the polyurethane decomposition product, the compatibility between the polyol-containing phase and the amine component-containing phase is poor, and the polyurethane decomposition product is easily phase-separated. For example, when ethylene glycol or diethanolamine is used as a decomposition agent for the polyurethane resin, the polyurethane decomposition product is obtained in a state of phase separation into an upper phase containing the polyol and a lower phase containing the amine component. When the polyurethane decomposition product is in a phase-separated state, the effective utilization of the lower phase is currently an issue. For example, the lower phase contains many amine components other than the amine components derived from the isocyanate, which is the raw material of the polyurethane resin. Therefore, it is difficult to isolate the amine components derived from the isocyanate, which is the raw material of the polyurethane resin, from the lower phase. In addition, when the polyurethane decomposition product is in a phase-separated state, the lower phase accounts for about 30% to 40% by mass of the entire polyurethane decomposition product, so that discarding the lower phase leads to a decrease in the recycling rate of the polyurethane resin. On the other hand, if the polyurethane decomposition product can be obtained as a one-phase liquid, the polyurethane decomposition product can be used as it is for the production of recycled polyurethane resin. Therefore, the separation process of the polyol and the amine components can be omitted, and the amount of waste can be reduced compared to the case of discarding the lower phase.

[0035] Furthermore, if the polyurethane decomposition product can be obtained as a one-phase liquid, the solid content itself is less likely to be generated. The reason is unclear, but it is thought to be as follows. That is, when the polyurethane decomposition product is in a phase-separated state, the components derived from the polymer polyol, the flame retardant, etc. are localized in one of the phases, resulting in a localized high concentration, which is thought to make it easier for solid content to be generated. On the other hand, if the polyurethane decomposition product can be obtained as a one-phase liquid, the components derived from the polymer polyol, the flame retardant, etc. can be dispersed throughout the system, which is thought to make it less likely for solid content to be generated. Note that the present disclosure is not limited to this speculation.

[0036] The use of the polyurethane decomposition product is not particularly limited. The polyurethane decomposition product is suitable as a raw material for recycled polyurethane resin. For example, when the polyurethane decomposition product is a one-phase liquid, it can be easily mixed into a composition for recycled polyurethane resin as it is, and can be easily reused.

[0037] 3. Manufacturing method of polyurethane decomposition product In the method for producing a polyurethane decomposition product, a polyurethane resin is decomposed by the above-mentioned composition for decomposing polyurethane.

[0038] The decomposition conditions of the polyurethane resin are not particularly limited. From the viewpoint of improving the decomposition rate, the decomposition treatment method of the polyurethane resin may be to heat the polyurethane resin together with the polyurethane decomposition composition. When heating the polyurethane resin together with the polyurethane decomposition composition, it is preferable to stir the mixture of the polyurethane resin and the polyurethane decomposition composition.

[0039] The heating temperature is preferably 80°C or higher and 300°C or lower, more preferably 100°C or higher and 270°C or lower, and even more preferably 150°C or higher and 250°C or lower, from the viewpoint of improving the decomposition rate while suppressing the decomposition of the polyol as a polyurethane decomposition product, i.e., the polyol derived from the raw material polyol. The decomposition treatment time is, for example, from 10 minutes to 24 hours, and may be from 30 minutes to 10 hours. The end point of the decomposition treatment time may be appropriately set while checking the progress of decomposition of the polyurethane resin depending on the size of the polyurethane resin, whether stirring is performed, etc. Furthermore, for example, when the polyurethane resin is decomposed at room temperature (e.g., 25°C) or higher and lower than 80°C, the decomposition treatment time may be set to be longer than 24 hours.

[0040] 4.How to decompose polyurethane resin In the method for decomposing a polyurethane resin, the polyurethane resin is decomposed by the above-mentioned polyurethane decomposition composition. The method for decomposing a polyurethane resin can be carried out under the same conditions as those in the above-mentioned "3. Method for producing a polyurethane decomposition product". For the conditions of the method for decomposing a polyurethane resin, refer to the explanation of the above-mentioned "3. Method for producing a polyurethane decomposition product", and detailed explanation will be omitted.

[0041] 5. Manufacturing method of recycled polyurethane resin In the method for producing a recycled polyurethane resin, a polyurethane decomposition product is used to produce a recycled polyurethane resin. In the manufacturing method of recycled polyurethane resin, the explanation in the section "2. Polyurethane decomposition products" applies as is and the description is omitted.

[0042] The recycled polyurethane resin can be obtained from a composition for recycled polyurethane resin, which contains, for example, a polyol, an isocyanate, and a polyurethane decomposition product. The recycled polyurethane resin can be produced by a known method. The foaming method for obtaining polyurethane foam includes slab foaming and mold foaming, and either molding method may be used. Slab foaming is a method in which a mixed recycled polyurethane resin composition is discharged onto a belt conveyer and foamed at atmospheric pressure and room temperature. On the other hand, mold foaming is a method in which a mixed recycled polyurethane resin composition is filled into a mold (molding die) and foamed in the mold. EXAMPLES

[0043] 1. Manufacture of polyurethane resin Compositions for polyurethane foam (liquids A and B) were prepared in the proportions shown in Table 1, and polyurethane foam A, polyurethane foam B, and polyurethane foam C were produced by slab foaming. The densities of the resulting polyurethane foam A, polyurethane foam B, and polyurethane foam C were measured in accordance with JIS K7222:2005. The measured densities are also shown in Table 1.

[0044] The details of each raw material are as follows: Polyol 1: Polyether polyol, number average molecular weight 3000, functionality 3, hydroxyl value 56.1 mgKOH / g, product name: Sannix GP-3050NS, manufactured by Sanyo Chemical Industries, Ltd. Polyol 2: Polymer polyol (polymer content 41%), number average molecular weight: 3000, functionality 3, hydroxyl value 32 mgKOH / g, product name: EL941WF, manufactured by AGC Inc. 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 Flame retardant: Chlorinated phosphate ester, product name: CR-504L, manufactured by Daihachi Chemical Industry Co., Ltd. Isocyanate: Tolylene diisocyanate, product name: Coronate T-80, manufactured by Tosoh Corporation, NCO%: 48.2%

[0045] [Table 1]

[0046] 2.Decomposition of polyurethane resin Examples and Comparative Examples of polyurethane decomposition compositions were prepared containing the components shown in Tables 2 and 3. Using the Examples and Comparative Examples of polyurethane decomposition compositions, the polyurethane resins of Polyurethane Foam A, Polyurethane Foam B, and Polyurethane Foam C were decomposed as follows.

[0047] The decomposition agents in Examples 1 to 8 are amino alcohols having neither a primary amino group nor a secondary amino group. The details of the decomposition agents are as follows. Example 1, Example 2, Example 6 to Example 8: N,N,N',N'-Tetrakis(2-hydroxypropyl)ethylenediamine Example 3: N-Phenyldiethanolamine Example 4: Triethanolamine Example 5: N,N-Dimethylaminohexanol In Table 1, the polyether polyol has a molecular weight of 3000 and a functional group of 3, and is Sannix GP-3050NS, manufactured by Sanyo Chemical Industries, Ltd.

[0048] In a 1 L separable flask, the polyurethane decomposition compositions of the Examples and Comparative Examples were added to 100 g of each polyurethane resin. The amounts of each component of the polyurethane decomposition composition added are shown in Tables 2 and 3. After the polyurethane decomposition composition was added, the mixture was heated at 200° C. for 6 hours with stirring to obtain a polyurethane decomposition product.

[0049] [Table 2]

[0050] [Table 3]

[0051] 3. Evaluation method The "phase separation" of the resulting polyurethane decomposition products was evaluated by the following evaluation method. <Phase separation> The presence or absence of phase separation was visually confirmed, and the criteria for judging were as follows: A: No phase separation. B: Solids are visible, but no clear phase separation is observed. C: Clear phase separation.

[0052] The "filtration residue" of the obtained polyurethane decomposition product was evaluated by the following evaluation method. <Filtration residue> For Examples 1 to 7, 100 parts by mass of the obtained polyurethane decomposition product was diluted by adding 50 parts by mass of polyether polyol (number average molecular weight 3000, number of functional groups 3, product name: Sannix GP-3050NS, manufactured by Sanyo Chemical Industries, Ltd.). Thereafter, the residue mass after leaving it for 24 hours under normal pressure was measured using a 40-mesh stainless steel wire net. The residue mass relative to the mass before filtration was evaluated in terms of mass percentage. For Example 8, the above dilution was not performed because the polyurethane decomposition composition contained the above polyether polyol. Evaluation was performed in the same manner as in Examples 1 to 7, except that dilution was not performed. When the above-mentioned phase separation was evaluated as "C", that is, when phase separation was clearly confirmed, the filtration residue was not evaluated. The criteria for judgment are as follows: A: The residue amount is 5% or less. B: The amount of residue is more than 5% and less than 15%. C: Residue amount is more than 15%.

[0053] The obtained polyurethane decomposition products were comprehensively evaluated according to the following criteria. A: For each of the polyurethane resins, Polyurethane Foam A, Polyurethane Foam B, and Polyurethane Foam C, the "phase separation" rating was "A" and the "filtration residue" rating was also "A". B: For each of the polyurethane resins, Polyurethane Foam A, Polyurethane Foam B, and Polyurethane Foam C, there is a "B" in the evaluation of "phase separation" and / or the evaluation of "filtration residue", but there is no "C" in the evaluation of either "phase separation" or "filtration residue". C: For each of the polyurethane resins, Polyurethane Foam A, Polyurethane Foam B, and Polyurethane Foam C, the evaluation of "phase separation" and / or the evaluation of "filtration residue" is "C."

[0054] 4.Results The evaluation results are shown in Tables 2 and 3. Examples 1 to 8 satisfy the following requirements (a) to (c), while Comparative Examples 1 to 4 do not satisfy the following requirement (b). Requirement (a): A composition for decomposing polyurethanes, comprising a decomposing agent and a catalyst. Requirement (b): The decomposition agent is an amino alcohol having neither a primary amino group nor a secondary amino group. Requirement (c): The catalyst is a tertiary amine compound having no hydroxyl group.

[0055] The overall evaluation of Examples 1 to 8 was "A" or "B." On the other hand, the overall evaluation of Comparative Examples 1 to 4 was "C." Examples 1 to 8, which satisfied the requirements (a) to (c), were able to obtain polyurethane decomposition products that were easier to use as recycled urethane raw materials than Comparative Examples 1 to 4.

[0056] Among Examples 1 to 8, Examples 6 to 8 further satisfy the following requirement (d). Requirement (d): Further, it contains polyol (excluding amino alcohol). Examples 6 to 8, which further satisfied requirement (d), were able to obtain polyurethane decomposition products that were even more easily usable as recycled urethane raw materials.

[0057] 5. Effects of the embodiment According to this embodiment, a technique for easily obtaining polyurethane decomposition products that can be easily used as recycled urethane raw materials can be provided.

[0058] The present disclosure is not limited to the embodiments described above in detail, and various modifications and variations are possible within the scope of the present disclosure.

Claims

1. A composition for decomposing polyurethane, comprising a decomposition agent and a catalyst, The decomposition agent is an amino alcohol having no primary amino group or no secondary amino group, The composition for decomposing polyurethane, wherein the catalyst is a tertiary amine compound having no hydroxyl group.

2. The polyurethane decomposition composition according to claim 1 , further comprising a polyol (excluding amino alcohol).

3. A polyurethane decomposition product obtained by decomposing a polyurethane resin with the polyurethane decomposition composition according to claim 1 or 2.

4. A method for producing a polyurethane decomposition product, comprising decomposing a polyurethane resin with the polyurethane decomposition composition according to claim 1 or 2.

5. A method for decomposing a polyurethane resin, comprising decomposing the polyurethane resin by using the composition for decomposing a polyurethane according to claim 1 or 2.

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