Method for decomposing polyurethane resin and method for producing recycled polyol

Abstract

The present invention provides a method for decomposing polyurethane resin and a method for producing recycled polyol. [Solution] The decomposition treatment method is a decomposition treatment method in which polyurethane resin 10 wrapped in packaging material 20 or polyurethane resin 10 contained in a container is chemically decomposed, wherein the packaging material 20 or container mainly contains polyester resin, and the packaging material 20 or container is also decomposed during the chemical decomposition.

Description

Technical Field

[0001] The present disclosure relates to a method for decomposing polyurethane resin and a method for producing recycled polyol.

Background Art

[0002] Patent Document 1 discloses a method for decomposing and recovering polyurethane. In this method, glycol decomposition is performed using diethylene glycol as a decomposing agent, and propylene glycol or dipropylene glycol is added as a homogenizing agent having a SP value lower than that of the decomposing agent to prevent phase separation.

[0003] Patent Document 2 discloses a method for producing recycled polyol. In this method, glycol decomposition is performed using glycerin or low-molecular glycol as a decomposing agent, and a delayed catalyst such as a DBU salt is used to reduce the influence of the catalyst during the production of recycled foam.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, a technique for decomposing a polyurethane resin by putting it in a packaging material or container such as a bag is desired. However, it is troublesome to take out the polyurethane resin contained in the packaging material or container and perform the decomposition treatment. Further, when the polyurethane resin to be decomposed is waste raw materials or scraps discharged during the manufacturing process, it is desirable to perform the treatment without taking out the polyurethane resin from the packaging material or container in terms of safety and odor.

[0006] This disclosure is made in view of the above circumstances and aims to solve at least one of the above problems. This disclosure can be implemented in the following forms. [Means for solving the problem]

[0007] A decomposition method for chemically decomposing polyurethane resin wrapped in packaging material or polyurethane resin contained in a container, The aforementioned packaging material or container contains polyester resin as its main component, A method for decomposing polyurethane resin, wherein the packaging material or the container is also decomposed during the chemical decomposition process. [Effects of the Invention]

[0008] This disclosure solves at least one of the above problems. For example, it is possible to decompose polyurethane resin while it is still in packaging materials such as bags or containers, providing a simple, safe, and odor-free technology. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram showing polyurethane resin and an example of packaging material. [Figure 2] This is a schematic diagram showing an example of polyurethane resin wrapped in packaging material. [Figure 3] This is a schematic diagram showing polyurethane resin and a modified example of packaging material 1. [Figure 4] This is a schematic diagram showing polyurethane resin and a modified example of packaging material (2). [Figure 5] This is a schematic diagram showing a modified example 2 of polyurethane resin wrapped in packaging material. [Figure 6] This diagram schematically shows the state before the disassembly process. [Figure 7] This diagram schematically shows the state after the disassembly process. [Modes for carrying out the invention]

[0010] Herein lies a preferred example of this disclosure. [1] A decomposition method for chemically decomposing polyurethane resin wrapped in packaging material or polyurethane resin contained in a container, The aforementioned packaging material or container contains polyester resin as its main component, A method for decomposing polyurethane resin, wherein the packaging material or the container is also decomposed during the chemical decomposition process. [2] A method for decomposing polyurethane resin according to [1], wherein the polyurethane resin is chemically decomposed with a compound having a hydroxyl group. [3] After the chemical decomposition, A phase containing a polyol component derived from polyurethane resin, A phase containing components derived from polyester resin, A method for decomposing polyurethane resin as described in [1] or [2], wherein the polyurethane resin is in a separated state. [4] A method for producing recycled polyols, comprising chemically decomposing polyurethane resin wrapped in packaging material or polyurethane resin contained in a container to recover polyol components, The aforementioned packaging material or container contains polyester resin as its main component, A method for producing recycled polyol, wherein the packaging material or the container is also decomposed during the chemical decomposition process. [5] A method for producing a regenerated polyol according to [4], comprising chemical decomposition with a compound having a hydroxyl group. [6] After the chemical decomposition, A phase containing a polyol component derived from polyurethane resin, A phase containing components derived from polyester resin, A method for producing a regenerated polyol according to [4] or [5], wherein the polyol is in a separated state.

[0011] Hereinafter, the present disclosure will be described in detail. In this specification, for a description using "-" for a numerical range, unless otherwise specified, it shall include the lower limit value and the upper limit value. For example, in the description of "10-20", both the lower limit value "10" and the upper limit value "20" are included. That is, "10-20" has the same meaning as "10 or more and 20 or less". Also, in this specification, the upper limit value and the lower limit value of each numerical range can be arbitrarily combined.

[0012] 1. Method for decomposing polyurethane resin 10 The decomposition treatment method is a decomposition treatment method for chemically decomposing the polyurethane resin 10 wrapped by the packaging material 20 or the polyurethane resin 10 contained in a container, wherein the packaging material 20 or the container contains a polyester resin as a main component, and at the time of chemical decomposition, the packaging material 20 or the container is also decomposed.

[0013] (1) Polyurethane resin 10 The polyurethane resin 10 may be a polyurethane foam or a non-foamed polyurethane resin. The polyurethane foam may be any of a soft polyurethane foam, a semi-rigid polyurethane foam, and a rigid polyurethane foam. In the case of a polyurethane foam, it may be a polyurethane foam having an open-cell structure or a polyurethane foam having a closed-cell structure. The polyurethane resin 10 may be a pulverized product pulverized to a predetermined size. Also, the polyurethane resin 10 may be a cut product cut to a predetermined size. For example, it may be a string-like end material (slit waste) that appears when the end of a sheet-like polyurethane resin is cut off.

[0014] The polyurethane resin 10 may be, for example, scraps discharged during the manufacturing process of the polyurethane resin 10, and / or waste materials discharged during the manufacturing process of the polyurethane resin 10. Waste materials discharged during the manufacturing process of the polyurethane resin 10 (e.g., drop waste) may be difficult to handle due to stickiness, etc. The technology of this disclosure ensures that even polyurethane resin 10 that is difficult to handle can be handled by wrapping it in packaging material 20 or housing it in a container.

[0015] The polyurethane resin 10 may be, for example, used polyurethane resin 10 that is scheduled to be discarded. Used polyurethane resin 10 may be in poor sanitary conditions. The technology of this disclosure makes it difficult to touch the polyurethane resin 10, even if it is in poor sanitary conditions, by wrapping it in packaging material 20 or placing it in a container, thereby ensuring the safety of workers.

[0016] (2) Packaging material 20 or container The polyurethane resin 10 is wrapped in packaging material 20. From the viewpoint of volume reduction, it is preferable that the polyurethane resin 10 be wrapped in packaging material 20 in a compressed state. The polyurethane resin 10 may be contained in a container. From the viewpoint of volume reduction, it is preferable that the polyurethane resin 10 be contained in the container in a compressed state.

[0017] The packaging material 20 is not limited in form as long as it has the function of enclosing the polyurethane resin 10. The packaging material 20 is preferably in the form of a bag, a box, or a film.

[0018] Figures 1 and 2 show examples of bag-shaped packaging materials 20. The bag-shaped packaging material 20 contains and wraps the polyurethane resin 10. The bag-shaped packaging material 20 is also an example of a container for containing the polyurethane resin 10. The bag-shaped packaging material 20 may be sealed after the polyurethane resin 10 has been placed inside. The bag-shaped packaging material 20 is convenient because it can easily wrap the polyurethane resin 10 simply by putting the polyurethane resin 10 inside. Furthermore, the bag-shaped packaging material 20 can cover the entire surface of the polyurethane resin 10, making it suitable for polyurethane resin 10 that is difficult to handle or polyurethane resin 10 that is in poor sanitary conditions. Compared to the box-shaped packaging material 20 described later, the bag-shaped packaging material 20 can contribute to reducing the amount of material used for packaging material 20. Preferably, the bag-shaped packaging material 20 has a capacity corresponding to the volume of the reaction vessel 3 described later. By appropriately selecting the size of the bag-shaped packaging material 20, the polyurethane resin 10 can be packaged in a standard shape, making it easier to improve efficiency, such as automating the process of adding the resin to the reaction tank 3.

[0019] Modification 1 in Figure 3 is an example of a box-shaped packaging material 20. The box-shaped packaging material 20 contains the polyurethane resin 10 and wraps the polyurethane resin 10. The box-shaped packaging material 20 is also an example of a container for containing the polyurethane resin 10. The box-shaped packaging material 20 may be sealed after the polyurethane resin 10 has been placed inside. The box-shaped packaging material 20 is convenient because it can easily wrap the polyurethane resin 10 simply by putting the polyurethane resin 10 inside. Furthermore, the box-shaped packaging material 20 can cover the entire surface of the polyurethane resin 10, making it suitable for polyurethane resin 10 that is difficult to handle or polyurethane resin 10 that is in poor sanitary conditions. Since the box-shaped packaging material 20 can stand on its own, packaging or containing work is easier compared to the bag-shaped packaging material 20. The box-shaped packaging material 20 preferably has a shape and capacity corresponding to the reaction tank 3 described later, for example. By appropriately selecting the shape and size of the box-shaped packaging material 20, the polyurethane resin 10 can be packaged in a standardized form, making it easier to improve efficiency, such as automating the process of adding the resin to the reaction tank 3.

[0020] Figures 4 and 5 show examples of film-like packaging material 20. Figure 5 shows an example of polyurethane resin 10 wrapped in film-like packaging material 20. The polyurethane resin 10 is wound into a roll, and the film-like packaging material 20 is wrapped around its outer circumference. The film-like packaging material 20 is easy to use as it can simply wrap the polyurethane resin 10 by wrapping it around the roll. Furthermore, the film-like packaging material 20 can cover the entire surface of the polyurethane resin 10, making it suitable for polyurethane resin 10 that is difficult to handle or has poor hygiene.

[0021] The packaging material 20 or container mainly contains polyester resin. In this specification, "main component" refers to the component that accounts for the largest mass percentage when the total of the object is 100% by mass, preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more. The upper limit of the polyester resin content may be 100% by mass.

[0022] The polyester resin is preferably at least one selected from the group consisting of aromatic polyesters and aliphatic polyesters. The aromatic polyester is preferably at least one selected from the group consisting of polyethylene terephthalate (PET), polypropylene terephthalate (PPT), and polybutylene terephthalate (PBT).

[0023] The softening point of polyester resin is not particularly limited. The softening point of polyester resin is preferably lower than the decomposition treatment temperature described later, for example, 60°C to 120°C, in order to facilitate the unpacking by heating. The softening point of polyester resin is the Vicat softening point measured according to JIS K 7206:2016.

[0024] The intrinsic viscosity of polyester resin is not particularly limited. For example, the intrinsic viscosity of polyester resin is between 0.3 dl / g and 2.0 dl / g. The above intrinsic viscosity is measured by dissolving the polyester resin in a 6 / 4 (by weight ratio) mixed solvent of phenol / 1,1,2,2-tetrachloroethane and measuring it at a temperature of 30°C.

[0025] (3) Decomposing agent It is preferable to use a decomposition agent in the decomposition process. However, if the polyurethane resin 10 itself contains a compound that acts as a decomposition agent, or if moisture in the treatment atmosphere acts as a decomposition agent, it is not always necessary to add a decomposition agent.

[0026] The decomposition agent is not particularly limited as long as it can chemically decompose the urethane bond. From the viewpoint of reactivity and cost, compounds having a hydroxyl group or amine components are preferred as decomposition agents. Examples of compounds containing hydroxyl groups include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, trimethylene glycol, 1,4-butanediol, 1,5-pentadiol, and 1,6-hexanediol. These compounds containing hydroxyl groups can be used individually or in combination of two or more. Examples of amine components include ethylenediamine, tetramethylenediamine, hexamethylenediamine, propanediamine, 2-ethylhexylamine, isopropanolamine, 2-(2-aminoethylamino)ethanol, 2-amino-2-hydroxymethyl-1,3-propanediol, ethylaminoethanol, aminobutanol, n-propylamine, di-n-propylamine, 3,3'-diaminodipropylamine, 3,3'-diamino-N-methyldipropylamine, n-amylamine, isobutylamine, methyldiethylamine, monoethanolamine, diethanolamine, triethanolamine, di-2-propanolamine, 2-(2-aminoethoxy)ethanol, cyclohexylamine, piperazine, piperidine, aniline, toluidine, benzylamine, phenylenediamine, tolylenediamine, 4,4'-diphenylmethanediamine, xylylenediamine, pyridine, picoline, and pyrazole. These amine components can be used individually or in combination of two or more.

[0027] It is more preferable that the decomposition agent is a compound having a hydroxyl group. When the decomposition agent is a compound having a hydroxyl group, the packaging material 20 or container can also be suitably chemically decomposed. The inventors of this application have also separately confirmed that the packaging material 20 or container can be chemically decomposed even when the decomposition agent is an amine component rather than a compound having a hydroxyl group.

[0028] The amount of decomposition agent added is preferably 5 to 50 parts by mass, more preferably 6 to 40 parts by mass, and even more preferably 7 to 30 parts by mass, per 100 parts by mass of polyurethane resin.

[0029] (4) Decomposition catalyst In decomposition reactions using a decomposition agent, the reaction rate can be increased by adding a decomposition catalyst (hereinafter also referred to as a catalyst) as needed. Preferably, the catalyst to be added is one used in the production of urethane, and for example, triethylamine, N,N-dimethylcyclohexylamine, N,N,N',N'-tetramethylethylenediamine, triethylenediamine, diazabicycloundecene, stanus octoate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin mercaptide, dibutyltin thiocarboxylate, dibutylindimaleate, dioctyltin mercaptide, dioctyltin thiocarboxylate, lead octyolate, potassium acetate, potassium octyolate, etc. can be used.

[0030] The amount of catalyst added is preferably 1 to 30 parts by mass, more preferably 3 to 25 parts by mass, and even more preferably 5 to 20 parts by mass, per 100 parts by mass of the decomposition agent.

[0031] 2. Method for disassembling polyurethane resin 10 wrapped in packaging material 20 One example of a decomposition method involves chemically decomposing the polyurethane resin 10 encased in packaging material 20. Another example of a decomposition method involves decomposing the packaging material 20 during the chemical decomposition process. This will be explained in detail below with reference to Figures 6 and 7.

[0032] (1) Decomposition device 1 The decomposition process can be carried out using a decomposition apparatus 1 equipped with a reaction tank 3 and a heating unit 5, as shown in Figures 6 and 7. The reaction tank 3 may also be equipped with a stirring unit (not shown) for stirring the contents.

[0033] (2) Preparation The decomposition process involves preparing polyurethane resin 10 wrapped in packaging material 20. The shape and size of the polyurethane resin 10 to be processed vary. In this decomposition process, the polyurethane resin 10 is preferably deformed and / or compressed to a size that fits in the reaction vessel 3 before being wrapped. The deformed and / or compressed polyurethane resin 10 will attempt to return to its original shape due to its elastic force. This decomposition process allows the shape of the deformed and / or compressed polyurethane resin 10 to be suitably maintained by using packaging material 20. If the polyurethane resin 10 exists as multiple small pieces, the multiple pieces of polyurethane resin 10 may be bundled together. Before being introduced into the reaction vessel 3, the polyurethane resin 10 should be stored and transported while wrapped in packaging material 20. For example, the waste material discharged during the manufacturing process can be packaged as is, stored, and transported to the reaction vessel 3. Alternatively, used polyurethane resin 10 can be packaged at the point of use and transported to the reaction vessel 3.

[0034] (3) Input The decomposition process involves directly placing the polyurethane resin 10, wrapped in packaging material 20, into the reaction vessel 3. Depending on the capacity of the reaction vessel 3, only one polyurethane resin 10 wrapped in packaging material 20 may be placed in, or multiple units may be placed in simultaneously or sequentially.

[0035] (4) Chemical decomposition Considering that the packaging material 20 or container will also undergo chemical decomposition, glycol decomposition, amine decomposition, or hydrolysis is preferred for the chemical decomposition. When the ester bonds of the polyester resin contained in the packaging material 20 are broken down by glycol decomposition, amine decomposition, or hydrolysis, decomposition products of the packaging material 20 are generated. For example, when polyethylene terephthalate (PET), which is a polyester resin, is glycol-decomposed by ethylene glycol, 2-hydroxyethyl terephthalate (BHET) is produced.

[0036] [ka]

[0037] The decomposition method involves chemical decomposition and / or heating to release the polyurethane resin 10 from its packaging by the packaging material 20. The heating temperature and other details will be explained later.

[0038] The unpackaged polyurethane resin 10 comes into contact with the decomposition agent in the reaction vessel 3 and is chemically decomposed. The decomposition products of the polyurethane resin 10 include polyol components derived from the raw material polyol and amine components derived from the raw material isocyanate. The decomposition products of the polyurethane resin 10 are usually liquid. The liquid decomposition product 13 flows down to the bottom of the reaction vessel 3 and remains in the reaction vessel 3 together with the decomposition agent or water. The reaction vessel 3 contains the decomposition products of the packaging material 20 and the decomposition products of the polyurethane resin 10, including polyol components derived from the raw material polyol and amine components derived from the raw material isocyanate. Hereinafter, the decomposition products of the packaging material 20 and the decomposition products of the polyurethane resin 10 as a whole will be referred to as the decomposition product 13.

[0039] When the chemical decomposition is glycol decomposition, the decomposed product 13 can be separated into a polyol phase 13A containing polyol components derived from the raw material polyol, and an amine phase 13B containing amine components derived from the raw material isocyanate. The amine phase 13B may also contain decomposition products of the packaging material 20. For example, 2-hydroxyethyl terephthalate, a decomposition product of the above-mentioned packaging material 20, is a compound that is solid at room temperature, and is therefore included in the amine phase 13B as a precipitate. In the examples described later, the amine phase 13B existed as a highly viscous liquid with a glass transition temperature (Tg) of 25°C or lower. The properties of the amine phase 13B were similar to peanut butter, a slightly hard paste-like substance with a large amount of solid dissolved in the liquid. On the other hand, the polyol phase 13A existed as a liquid with lower viscosity compared to the amine phase 13B. In the decomposed product 13 in this decomposition method, for example, the polyol phase 13A and the amine phase 13B are separated into liquid-liquid phases.

[0040] Even if the chemical decomposition is amine decomposition, it is thought that the phase containing the polyol component derived from the raw material polyol and the phase containing the amine component derived from the raw material isocyanate can be separated. Similarly, even if the chemical decomposition is hydrolysis, it is thought that the phase containing the polyol component derived from the raw material polyol and the phase containing the amine component derived from the raw material isocyanate can be separated. In the case of hydrolysis, it is presumed that the aqueous phase contains the amine component derived from the raw material polyurethane resin and a dicarboxylic acid (e.g., terephthalic acid) derived from the polyester resin, while the oil phase contains the polyol component and a diol (e.g., ethylene glycol) derived from the polyester resin.

[0041] Furthermore, the decomposition product 13 is not limited to a state in which the phase containing the polyol component derived from the raw material polyol and the phase containing the amine component derived from the raw material isocyanate are separated. The decomposition product 13 may exist in a single-phase state containing the polyol component derived from the raw material polyol and the amine component derived from the raw material isocyanate. Even in that case, it is preferable that the decomposition product of the packaging material 20 be separated as a precipitate from the phase containing the polyol component derived from the raw material polyol.

[0042] (5) Conditions for the disassembly process The decomposition method preferably involves heating. Specifically, when the packaging material 20 reaches a predetermined temperature or higher, the packaging material 20 melts or softens. This makes it easier to unpack the polyurethane resin 10. Furthermore, heating promotes the chemical decomposition of the packaging material 20 and the polyurethane resin 10, thereby shortening the time required for the decomposition process.

[0043] The heating temperature in the decomposition process should be set to a temperature suitable for the decomposition of the material of the packaging material 20 and the polyurethane resin 10. For example, the heating temperature should be set to a temperature above the softening point of the material constituting the packaging material 20. The specific heating temperature is not particularly limited. The heating temperature is preferably 100°C to 250°C, more preferably 150°C to 230°C, and even more preferably 170°C to 220°C. The decomposition treatment time in the decomposition treatment method may be, for example, 10 minutes to 24 hours, or 30 minutes to 10 hours. The end point of the decomposition treatment time may be set appropriately while checking the progress of the decomposition of the polyurethane resin 10, depending on the size of the polyurethane resin 10, whether or not it is stirred, etc. Furthermore, for example, when decomposing the polyurethane resin 10 at room temperature (e.g., 25°C) or higher but less than 80°C, the decomposition treatment time may be set to be longer than 24 hours.

[0044] Then, when the temperature of the packaging material 20 in the reaction vessel 3 drops below a predetermined temperature (for example, 70°C), the decomposition products of the packaging material 20 solidify. The decomposition products of the packaging material 20 in their solidified state are easily separated from the liquid polyol component, and the polyol component can be easily recovered. The method for recovering the polyol component will be described later.

[0045] 3. Method for decomposing polyurethane resin 10 contained in a container Another example of a decomposition method is to chemically decompose the polyurethane resin 10 contained in the container. Another example of a decomposition method is to decompose the container during the chemical decomposition process.

[0046] In "3. Method for Decomposing Polyurethane Resin 10 Contained in a Container," the decomposition apparatus 1, preparation, input, and chemical decomposition are applied as is, replacing "polyurethane resin 10 wrapped in packaging material 20" with "polyurethane resin 10 contained in a container" in the sections "(1) Decomposition apparatus 1," "(2) Preparation," "(3) Input," "(4) Chemical decomposition," and "(5) Conditions for decomposition treatment" in the section "2. Method for Decomposing Polyurethane Resin 10 Wrapped in Packaging Material 20" above, and replacing other mentions of "packaging material 20" with "container."

[0047] 4. Method for producing recycled polyols The method for producing recycled polyol involves chemically decomposing polyurethane resin 10 wrapped in packaging material 20 or polyurethane resin 10 contained in a container to recover the polyol component, wherein the packaging material 20 or container mainly contains polyester resin, and the packaging material 20 or container is also decomposed during the chemical decomposition process. In the description of the method for manufacturing recycled polyol, the methods for chemically decomposing the polyurethane resin 10 wrapped in packaging material 20 or the polyurethane resin 10 contained in a container shall be as described in the sections "1. Method for decomposing polyurethane resin 10", "2. Method for decomposing polyurethane resin 10 wrapped in packaging material 20", and "3. Method for decomposing polyurethane resin 10 contained in a container".

[0048] The method for producing a recycled polyol according to this disclosure recovers the polyol component. From the viewpoint of quality (reactivity) as a recycled polyol, the polyol component is preferably recovered as a polyol phase 13A separated from the phase containing the amine component derived from the raw material isocyanate. The method for recovering the polyol component from the decomposition product 13 is not particularly limited. Specifically, the polyol component may be recovered, for example, by decanting the upper polyol phase 13A. In this case, it is preferable that the viscosity of the amine phase 13B is high so that the amine phase 13B does not easily mix with the polyol phase 13A. The technology of this disclosure is preferable in that the viscosity of the amine phase 13B can be increased by the components of the packaging material 20, making it easier to recover the polyol phase 13A. In addition, the polyol component may be recovered by pumping out only the polyol phase 13A, or it may be separated from the amine phase 13B by filtration and recovered as a filtrate.

[0049] In the method for producing recycled polyols, the recovery rate of the recycled polyol is not particularly limited. The recovery rate of the recycled polyol can be evaluated as the recovery rate of the polyol phase 13A recovered by decantation from the decomposition product 13, using the following formula. Recovery rate of the polyol phase (%) = (A / B) × 100 A: Mass of recovered polyol phase (g) B: The total mass (g) of the polyurethane resin used for decomposition and the decomposition agent.

[0050] From the viewpoint of efficiently obtaining recycled polyol, the recovery rate of the polyol phase 13A is preferably 15% or more, and more preferably 20% or more. The upper limit of the recovery rate of the polyol phase 13A is not particularly limited and may be 95% or less, 70% or less, or 50% or less.

[0051] A major difference between the polyol phase 13A recovered as described above and virgin polyol is that the recovered polyol phase 13A contains a hydroxyl group compound (e.g., ethylene glycol) used as a decomposition agent. Such low molecular weight hydroxyl group compounds and water can affect the physical properties of recycled polyurethane resin when recycled polyol is used in the production of recycled polyurethane resin. From the viewpoint of removing low molecular weight hydroxyl group compounds, a method for producing recycled polyol is to remove the hydroxyl group compound used as a decomposition agent from the recovered polyol phase 13A by vacuum distillation. At this time, it is also preferable to remove water along with the hydroxyl group compound by vacuum distillation. Depending on the application, the method for producing recycled polyol may be to use the recovered polyol phase as is as recycled polyol.

[0052] When polyurethane resin 10 containing a foam stabilizer as a raw material is subjected to decomposition treatment, a large amount of the foam stabilizer remains in the polyol phase 13A and can be used as is in the production of recycled polyurethane resin. In other words, the recycled polyol may contain a foam stabilizer derived from the polyurethane resin that was decomposed.

[0053] The applications of recycled polyols are not particularly limited. Recycled polyols are suitable as raw materials for recycled polyurethane resins.

[0054] 5. Effects of this embodiment In this embodiment, waste generated during the manufacture of polyurethane resin 10 and waste materials of polyurethane resin 10 can be fed into the dismantling device 1 while still wrapped in packaging material 20 or contained in a container, and then dismantled. Therefore, the effort required to unpack or remove from containers is reduced, and the work efficiency of the dismantling process can be improved. Furthermore, this embodiment allows for safe processing regardless of the state of the polyurethane resin 10, whether it is in a liquid, semi-solid, or solid state, such as a raw material for disposal, by avoiding contact with the polyurethane resin 10 itself. Furthermore, in this embodiment, since the product can be stored and transported while wrapped in the packaging material 20 or contained in a container, odors generated from the polyurethane resin 10 can be suppressed before the decomposition process. [Examples]

[0055] 1. Preparation of polyurethane resin wrapped in packaging material. As decomposable polyurethane foam, we prepared discarded raw materials (drop waste) generated during the manufacturing process of polyurethane foam produced in the proportions listed in Table 1. The drop waste was in a sludgy, semi-solid state. The details of the raw materials are as follows: • Polyether polyol 1: Polypropylene glycol, average number of functional groups: 2, number average molecular weight: 2000 • Polyether polyol 2: Polypropylene glycol, average number of functional groups: 2, number average molecular weight: 400 • Polyester polyol: Polycaprolactone diol, average number of functional groups: 2, number average molecular weight: 500 • Silicone-based foam stabilizer: SZ-1952, manufactured by Toray Dow Corning. • Iron catalyst: FIN-P1, manufactured by Nippon Chemical Industrial Co., Ltd. • Hindered phenol antioxidant: IRGANOX 1135, manufactured by BASF Japan. • Aluminum hydroxide: CW-325LV, manufactured by Sumitomo Chemical Co., Ltd. • Carbon Black • Desiccant: Molecular Sieve 3A, manufactured by Union Showa Co., Ltd. • Isocyanate: Polymeric MDI, average number of functional groups: 2.4, number-average molecular weight: 320, NCO: 32%

[0056] As a packaging material containing polyester resin as the main component, a PET bag (manufactured by Toyobo Co., Ltd., Oriester®, 30 μm thick) was prepared. 100 parts by mass of decomposable polyurethane foam were placed in 1 part by mass of the bag and packaged to create a sample.

[0057] [Table 1]

[0058] 2. Disassembly process The above sample was placed in a 1 L separable flask, and 10 parts by mass of ethylene glycol as a decomposition agent and 1 part by mass of diazabicycloundecene (DBU) as a catalyst were added. Chemical decomposition was carried out at 200°C for 5 hours under a nitrogen flow. As a result, a decomposition product was obtained that separated into two phases: the upper phase being a polyol phase and the lower phase being an amine phase.

[0059] The lower phase (amine phase) was a slightly hard, paste-like, high-viscosity liquid. The upper phase (polyol phase) was a lower-viscosity liquid than the lower phase. Analysis of the upper and lower phases by LC-MS revealed that 2-hydroxyethyl terephthalate (BHET), a decomposition product of the packaging material, was almost entirely contained in the lower phase.

[0060] 3. Recovery of polyol components The polyol phase was recovered from the decomposition product by decantation. The recovery rate of the polyol phase was approximately 30%. Ethylene glycol and water were removed from the polyol phase by reduced-pressure distillation at 180°C to obtain regenerated polyol.

[0061] The raw materials were blended in the proportions shown in Table 1, and recycled polyurethane foam was obtained by slab foaming. In Table 1, "recovered polyol" refers to recycled polyol recovered by decomposing the decomposed polyurethane foam. This example confirmed that a practical recycled polyurethane resin can be produced.

[0062] 4. Effects of the Examples This embodiment provides a method for decomposing polyurethane resin and a method for producing recycled polyol. For example, the polyurethane resin can be decomposed while still in packaging materials such as bags or containers, providing a simple, safe, and odor-free technology.

[0063] This disclosure is not limited to the embodiments detailed above, and various modifications or alterations are possible. [Explanation of Symbols]

[0064] 1...Disassembly device 3…Reaction vessel 5...Heating section 10…Polyurethane resin 13…Decomposed materials 13A...Polyol phase 13B... Amine phase 20… Packaging materials

Claims

1. A decomposition method for chemically decomposing polyurethane resin wrapped in packaging material or polyurethane resin contained in a container, The aforementioned packaging material or container contains polyester resin as its main component, A method for decomposing polyurethane resin, wherein the packaging material or the container is also decomposed during the chemical decomposition process.

2. A method for decomposing a polyurethane resin according to claim 1, wherein the resin is chemically decomposed by a compound having a hydroxyl group.

3. After the aforementioned chemical decomposition, A phase containing a polyol component derived from polyurethane resin, A phase containing components derived from polyester resin, A method for decomposing polyurethane resin according to claim 1 or claim 2, wherein the polyurethane resin is in a separated state.

4. A method for producing recycled polyols, comprising chemically decomposing polyurethane resin wrapped in packaging material or polyurethane resin contained in a container to recover polyol components, The aforementioned packaging material or container contains polyester resin as its main component, A method for producing recycled polyol, wherein the packaging material or the container is also decomposed during the chemical decomposition process.

5. A method for producing a recycled polyol according to claim 4, wherein the polyol is chemically decomposed with a compound having a hydroxyl group.

6. After the aforementioned chemical decomposition, A phase containing a polyol component derived from polyurethane resin, A phase containing components derived from polyester resin, A method for producing a regenerated polyol according to claim 4 or claim 5, wherein the polyol is in a separated state.

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