Composition for polyurethane decomposition, polyurethane decomposed product, and method for producing polyurethane decomposed product

Abstract

To provide a decomposition product readily utilizable as a recycled material.SOLUTION: A composition for polyurethane decomposition comprising a first compound and a second compound, the first compound being polyethylene glycol and the second compound being an aromatic polyol.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] Attempts have been made to chemically decompose and reuse polyurethane foam scraps, used polyurethane foam, and the like (see, for example, Patent Documents 1 to 6). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-109540 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-105194 [Patent Document 3] Japanese Patent Application Laid-Open No. 2002-037922 [Patent Document 4] Japanese Patent Application Laid-Open No. 2011-246568 [Patent Document 5] Japanese Patent Application Laid-Open No. 2011-246569 [Patent Document 6] Japanese Patent Application Laid-Open No. 2007-262174 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional methods, the decomposition products are not necessarily easy to use as recycled materials.

[0005] The present disclosure has been made in view of the above circumstances, and aims to obtain a decomposition product that can be easily used as a recycled raw material. The present disclosure can be realized in the following aspects. [Means for solving the problem]

[0006] A composition for decomposing polyurethane, comprising a first compound and a second compound, the first compound is polyethylene glycol; The composition for decomposing polyurethane, wherein the second compound is an aromatic polyol. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to obtain decomposition products that can be easily used as recycled raw materials. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram schematically illustrating an example of a decomposition treatment device. [Figure 2] FIG. 2 is a diagram schematically illustrating a pair of rolls taken along line II-II in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] Here, a preferred example of the present disclosure will be described. [1] A composition for decomposing polyurethane, comprising a first compound and a second compound, the first compound is polyethylene glycol; The composition for decomposing polyurethane, wherein the second compound is an aromatic polyol. [2] The composition for decomposing polyurethanes according to [1], wherein the second compound has a plurality of benzene rings each having a phenolic hydroxyl group. [3] The composition for decomposing polyurethane according to [1] or [2], wherein the second compound satisfies all of the following (i), (ii), and (iii): (i) Derived from cashew nut shells. (ii) The molecular weight is 500 or more. (iii) has a phenolic hydroxyl group; [4] A polyurethane decomposition product obtained by decomposing a polyurethane resin with the polyurethane decomposition composition according to any one of [1] to [3]. [5] A method for producing a polyurethane decomposition product, comprising decomposing a polyurethane resin with the polyurethane decomposition composition according to any one of [1] to [3]. [6] A method for decomposing a polyurethane resin, comprising decomposing the polyurethane resin with the polyurethane decomposition composition according to any one of [1] to [3]. [7] A method for producing polyurethane using the polyurethane decomposition product according to [4] as a raw material. [8] [4] A polyurethane using the polyurethane decomposition product as a raw material.

[0010] Here, examples of desirable decomposition treatment equipment and methods for decomposing polyurethane resins will be described. <1> a cylinder having a raw material inlet and a discharge port for discharging the decomposition product; a screw housed in the cylinder; The decomposition treatment device for polyurethane resins, wherein the raw material inlet is provided with an introduction mechanism that introduces a mixture of pulverized polyurethane resin and a composition for decomposing polyurethanes while forcing the mixture into the raw material inlet. <2> A method for decomposing a polyurethane resin using an extruder having a cylinder, comprising: A mixture of pulverized polyurethane resin and a composition for decomposing polyurethane is introduced into the raw material inlet of the cylinder while being pushed therethrough; The method for decomposing a polyurethane resin comprises heating the mixture while transferring it within the cylinder, thereby decomposing the polyurethane resin.

[0011] A particularly preferred example of a decomposition treatment device for polyurethane resin is shown below. The feeding mechanism has a pair of rotors arranged parallel to each other, and rotates the rotors in different directions to entrain the mixture between the pair of rotors and push the mixture into the raw material feeding port.

[0012] A particularly preferred example of a method for decomposing polyurethane resin will be described below. The mixture is introduced using a introducing mechanism having a pair of rotors arranged parallel to each other, The method for decomposing a polyurethane resin includes rotating the rotors in different directions to entrain the mixture between the pair of rotors and to push the mixture into the raw material inlet.

[0013] The present disclosure will be described in detail below. In this specification, when a numerical range is indicated using "-", it is intended to include both the lower limit and the upper limit unless otherwise specified. For example, the expression "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 addition, in this specification, the upper limit and lower limit of each numerical range can be combined in any way.

[0014] 1. Polyurethane decomposition composition The polyurethane decomposition composition of the present disclosure functions as a decomposition agent for decomposing polyurethane. The polyurethane decomposition composition includes a first compound and a second compound, the first compound being polyethylene glycol, and the second compound being an aromatic polyol.

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

[0016] (2) First compound The first compound is polyethylene glycol. The first compound is preferably polyethylene glycol represented by the following general formula (I): HO(CH2CH2O) n H (I) In general formula (I), n is an integer of 2 or greater, and from the viewpoint of compatibility with the polyurethane decomposition product, n is preferably an integer of 3 or greater, and more preferably an integer of 4 or greater. In general formula (I), n is an integer of 17 or less, and from the viewpoint of reducing the viscosity of the polyurethane decomposition product, n is preferably an integer of 16 or less, and may be any integer from 3 to 15. The polyethylene glycol of the present disclosure can ensure suitable fluidity of the polyurethane decomposition product while suppressing phase separation.

[0017] The polyethylene glycol represented by general formula (I) is, for example, a polyethylene glycol having a number-average molecular weight of 100 or more but less than 1,000. More specifically, examples include diethylene glycol, polyethylene glycol 100 (PEG100), polyethylene glycol 300 (PEG300), polyethylene glycol 600 (PEG600), polyethylene glycol 800 (PEG800), and polyethylene glycol 1000 (PEG1000). Among these, one or more selected from diethylene glycol, PEG300, and PEG600 are preferred. The number following polyethylene glycol (PEG) indicates the number-average molecular weight of the polyethylene glycol. For example, polyethylene glycol 100 (PEG100) indicates polyethylene glycol (PEG) having a number-average molecular weight of 100, and polyethylene glycol 300 (PEG300) indicates polyethylene glycol (PEG) having a number-average molecular weight of 300. Only one type of compound represented by general formula (I) may be used, or two or more types may be used in combination. The number average molecular weight of polyethylene glycol can be measured, for example, by gel permeation column chromatography (GPC).

[0018] (3)Second compound The second compound is an aromatic polyol. Examples of aromatic polyols include aromatic compounds having two or more hydroxyl groups. Examples of aromatic polyols include aromatic polyols having catechol, resorcinol, hydroquinone, and phenolic hydroxyl groups; aromatic polyols having alcoholic hydroxyl groups such as benzenedimethanol and benzenediethanol; and polymer-based aromatic polyols such as polycarbonate polyols containing an aromatic skeleton, polyester polyols containing an aromatic skeleton, polyether polyols containing an aromatic skeleton, and castor oil-based modified polyols containing an aromatic skeleton. Among these, aromatic polyols preferably have phenolic hydroxyl groups. The aromatic polyol preferably has multiple benzene rings on which phenolic hydroxyl groups exist. The phenolic hydroxyl groups are hydroxyl groups bonded to aromatic ring carbons. The second compound preferably satisfies all of the following (i), (ii), and (iii). (i) Derived from cashew nut shells. (ii) The molecular weight is 500 or more. (iii) has a phenolic hydroxyl group;

[0019] The aromatic polyol satisfying the above (i) is a polyol derived from cashew nut shell liquid (CNSL). Cashew nut shell liquid is an oily liquid contained in the shells of cashew nuts (cashew nut shells) and is prepared from cashew nut shells by extraction or heating. Cashew nut shell liquid is a renewable resource material and is a plant-derived starting material that is not derived from petroleum. Cashew nut shell liquid mainly contains anacardic acid, cardol, methyl cardol, and cardanol. The aromatic polyol is obtained from the distillation residue when cardanol is distilled from cashew nut shell liquid. It is preferable that the composition for decomposing polyurethane does not contain cardanol.

[0020] The aromatic polyol is preferably represented by the following structural formula (1).

[0021] [ka]

[0022] [In formula (1), R 1 , R 2 are each independently a hydrogen atom or a hydroxyl group, R 3 , R 4 are each a saturated or unsaturated divalent hydrocarbon group having from 10 to 25 carbon atoms. R 3 , R 4 The number of carbon atoms is preferably 12 or more and 20 or less, and more preferably 15.

[0023] The aromatic polyol of structural formula (1) is preferably the following structural formula (2).

[0024] [ka]

[0025] [In formula (2), each of the two R's is an alkylene group having 15 carbon atoms]

[0026] From the viewpoint of ensuring resin strength, the molecular weight of the aromatic polyol is 500 or more, preferably 550 or more, and more preferably 600 or more. The upper limit of the molecular weight of the aromatic polyol is usually 1,000 or less.

[0027] From the viewpoint of improving flame retardancy, the aromatic concentration of the aromatic polyol is preferably 10% or more, more preferably 15% or more, and even more preferably 20% or more. From the viewpoint of suppressing an increase in viscosity, the aromatic concentration of the aromatic polyol is preferably 40% or less, more preferably 30% or less, and even more preferably 25% or less. From these viewpoints, the aromatic concentration of the aromatic polyol is preferably 10% to 40% or less, more preferably 15% to 30% or less, and even more preferably 20% to 25% or less. The aromatic concentration of the aromatic polyol is obtained based on the total mass% of carbon atoms and hydrogen atoms constituting the aromatic rings in the aromatic polyol. The aromatic concentration of the aromatic polyol can be calculated using the method disclosed in the non-patent document (Chemistry and Technology of Polyols for Polyurethanes, M. Ionescu, Rapra Technology, 2005).

[0028] The hydroxyl value of the aromatic polyol is preferably from 100 mgKOH / g to 300 mgKOH / g, more preferably from 150 mgKOH / g to 270 mgKOH / g, and even more preferably from 180 mgKOH / g to 240 mgKOH / g.

[0029] The viscosity of the aromatic polyol at 25°C is preferably 600 cps or more and 5000 cps or less, more preferably 800 cps or more and 4500 cps or less, and even more preferably 1000 cps or more and 4000 cps or less.

[0030] The number of functional groups of the aromatic polyol is preferably 5 or less, more preferably 4 or less, and even more preferably 3 or less.

[0031] (4) Mass ratio of the first compound to the second compound The mass ratio of the first compound to the second compound is not particularly limited. From the viewpoint of sufficiently decomposing the polyurethane resin, the mass ratio of the first compound to the second compound (first compound:second compound) is preferably 1:0.05-1:10, more preferably 1:0.1-1:5, and even more preferably 1:0.3-1:1.

[0032] (5) Other ingredients The polyurethane decomposition composition may further contain components other than the first compound and the second compound (also referred to as other components).

[0033] 2. Polyurethane decomposition products The polyurethane decomposition product can be obtained by decomposing a polyurethane resin using the polyurethane decomposition composition.

[0034] Polyurethane decomposition products include, for example, polyols derived from raw polyols of polyurethane resins and amine components derived from raw isocyanates, as well as flame retardants, catalysts, and other additives contained in the polyurethane resins.

[0035] 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 term "one-phase liquid" means that the appearance of the decomposition liquid in the examples described below is evaluated as a "homogeneous liquid." 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 compatibilized state. The one-phase liquid may also contain solid components. Examples of the solid components include components derived from polymer polyols containing polymers such as styrene or acrylonitrile, and flame retardants such as phosphorus-based flame retardants and halogen-based flame retardants.

[0036] In polyurethane decomposition products, the polyol-containing phase and the amine-containing phase inherently have poor compatibility and are prone to phase separation. For example, when ethylene glycol or diethanolamine is used as a decomposition agent for polyurethane resins, the resulting polyurethane decomposition product is phase-separated into an upper phase containing the polyol and a lower phase containing the amine component. When polyurethane decomposition products are in a phase-separated state, effective utilization of the lower phase is currently a challenge. For example, the lower phase contains many amine components other than those derived from the isocyanate raw material of the polyurethane resin. Therefore, it is difficult to isolate the amine components derived from the isocyanate raw material of the polyurethane resin from the lower phase. Furthermore, when polyurethane decomposition products are in a phase-separated state, the lower phase accounts for approximately 30% to 40% by mass of the entire polyurethane decomposition product, and discarding the lower phase reduces the recycling rate of the polyurethane resin. On the other hand, if polyurethane decomposition products can be obtained as a single-phase liquid, they can be used directly to produce recycled polyurethane resins. This eliminates the need for a separation process for the polyol and amine components and contributes to reducing the amount of waste compared to discarding the lower phase.

[0037] 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 for this is unclear, but it is thought to be as follows. That is, if the polyurethane decomposition product is in a phase-separated state, the polymer polyol-derived polymer components, flame retardants, etc. are localized in one of the phases, resulting in a localized high concentration, making 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 polymer polyol-derived polymer components, flame retardants, etc. can be dispersed throughout the system, making it less likely for solid content to be generated. Note that the present disclosure is not limited to this speculation.

[0038] 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 as it is into a composition for recycled polyurethane resin, and can be easily reused.

[0039] In the present disclosure, a polyurethane resin using aromatic polyisocyanate as a raw material is preferred as the polyurethane resin. It is presumed that the polyurethane decomposition product obtained by decomposing a polyurethane resin using aromatic polyisocyanate as a raw material contains a compound derived from the aromatic polyisocyanate. The compound produced by this decomposition and the aromatic polyol, which is the second compound, are both aromatic, and therefore are highly compatible, which is thought to make the polyurethane decomposition product less susceptible to phase separation. The aromatic polyisocyanate is not particularly limited. Examples of aromatic polyisocyanates include 2,4-toluene diisocyanate (2,4-TDI), 2,6-toluene diisocyanate (2,6-TDI), m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate (4,4'-MDI), 2,4'-diphenylmethane diisocyanate (2,4'-MDI), 2,2'-diphenylmethane diisocyanate (2,2'-MDI), and the like. -MDI), hydrogenated MDI, xylylene diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, 3,3'-dimethoxy-4,4'-biphenylene diisocyanate, polymethylene polyphenyl polyisocyanate, 1,5-naphthalene diisocyanate, xylylene diisocyanate (XDI), hydrogenated XDI, and tetramethylxylene diisocyanate (TMXDI) are preferred examples.

[0040] 3. Manufacturing method of polyurethane decomposition product In the method for producing a polyurethane decomposition product, a polyurethane resin is decomposed using the above-mentioned polyurethane decomposition composition.

[0041] The conditions for decomposing the polyurethane resin are not particularly limited. From the viewpoint of improving the decomposition rate, the method for decomposing the polyurethane resin preferably involves heating 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.

[0042] In the present production method, the mass ratio of the polyurethane resin to the polyurethane decomposition composition (polyurethane resin:polyurethane decomposition composition) is not particularly limited. From the viewpoint of sufficiently decomposing the polyurethane resin, the mass ratio of the polyurethane resin to the polyurethane decomposition composition is preferably 1:0.1 to 1:10, more preferably 1:0.2 to 1:5, and even more preferably 1:1 to 1:2.

[0043] 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, or 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, when decomposing a polyurethane resin at a temperature between room temperature (e.g., 25°C) and below 80°C, the decomposition treatment time may be set to be longer than 24 hours.

[0044] 4. How to decompose polyurethane resin The method for decomposing a polyurethane resin involves decomposing the polyurethane resin using the polyurethane decomposition composition described above. The method for decomposing a polyurethane resin can be carried out under the same conditions as those described above in "3. Method for producing polyurethane decomposition products." The conditions for the method for decomposing a polyurethane resin are the same as those described above in "3. Method for producing polyurethane decomposition products," and a description thereof will be omitted.

[0045] 5. Manufacturing method of polyurethane resin (hereinafter referred to as "recycled polyurethane resin" in this section 5) In the method for producing recycled polyurethane resin, polyurethane resin is produced using polyurethane decomposition products. In the manufacturing method of recycled polyurethane resin, the explanation in the section "2. Polyurethane decomposition product" applies as is to the "polyurethane decomposition product," and the description thereof will be omitted.

[0046] The recycled polyurethane resin is obtained from a polyurethane resin composition containing, for example, a polyol, an isocyanate, and a polyurethane decomposition product. Recycled polyurethane resin can be produced by known methods. Foaming methods for obtaining polyurethane foam include 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 conveyor 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 (forming die) and foamed within the mold.

[0047] 6. Polyurethane resin decomposition treatment equipment 1 Here, an example of a desirable polyurethane resin decomposition treatment device 1 is shown. 1 and 2, the decomposition treatment device 1 for polyurethane resins includes a cylinder 20 having a raw material inlet 21 and an outlet 23 for discharging the decomposition product, and a screw 11 housed in the cylinder 20. The raw material inlet 21 is provided with a feeding mechanism 30 that feeds a mixture of pulverized polyurethane resin and a polyurethane decomposition composition while forcing it into the raw material inlet 21. Hereinafter, in the decomposition treatment device 1, the portion having the cylinder 20 and the screw 11 will also be simply referred to as the extruder 10.

[0048] (1) Extruder 10 The cylinder 20 has a substantially cylindrical shape. The cylinder 20 has a raw material inlet 21 at one end and a discharge outlet 23 at the other end. The cylinder 20 is provided with a heating unit 25 that heats the contents inside the cylinder 20.

[0049] The raw material inlet 21 is provided on the side surface of the cylinder 20. The raw material inlet 21 opens, for example, upward. Below the raw material inlet 21, the screw 11 is located.

[0050] The screw 11 is coaxial with the cylinder 20. The screw 11 has a spiral groove on its side. The screw 11 is driven to rotate by a drive unit 13. When driven to rotate, the screw 11 mixes the contents in the cylinder 20 and transports them toward the discharge port 23. The extruder 10 includes, for example, one screw 11. That is, the extruder 10 is a single-screw extruder. The extruder 10 may also include two screws 11.

[0051] (2) Loading mechanism 30 The feeding mechanism 30 feeds the mixture of pulverized polyurethane resin and decomposing agent while pushing it into the raw material feeding port 21. The feeding mechanism 30 includes, for example, a pair of rotors 33, 33, a drive unit (not shown) that drives the pair of rotors 33, 33 to rotate, and a hopper 31. In this embodiment, the pair of rotors 33, 33 are installed inside the hopper 31. The installation mode of the pair of rotors 33, 33 is not limited to this.

[0052] The pair of rotors 33, 33 are arranged parallel to each other. The configuration of each rotor 33, 33 is not particularly limited. For example, each rotor 33 has a plurality of teeth 35 arranged circumferentially on its outer circumferential surface. The teeth 35 form ridges extending in the axial direction of the rotor 33. Between the rotors 33, 33, the teeth 35 of one rotor 33 face the valleys between the teeth 35 of the other rotor 33. The pair of rotors 33, 33 are configured so that the teeth 35 of one rotor 33 and the teeth 35 of the other rotor 33 alternately push the mixture into each other.

[0053] The pair of rotors 33 may be configured to crush the polyurethane resin while pushing it in, or may be configured to push it in without crushing it. The configuration for crushing the polyurethane resin and the configuration for not crushing the polyurethane resin can be appropriately set, for example, by adjusting the size of the gap between the pair of rotors 33. Specifically, the polyurethane resin can be suitably crushed by making the gap between the pair of rotors 33 smaller than the size of the polyurethane resin passing between the pair of rotors 33. Furthermore, in the configuration for pulverizing the polyurethane resin, the polyurethane resin can be suitably crushed by appropriately designing the shape of the teeth provided on the outer circumferential surface of the rotor 33.

[0054] The hopper 31 has a generally rectangular box shape when viewed from above. The hopper 31 has an upper opening that opens upward. The upper opening of the hopper 31 is wider than the raw material inlet 21 of the cylinder 20. The hopper 31 has a lower opening that opens downward. The lower opening of the hopper 31 is connected to the raw material inlet 21 of the cylinder 20. The hopper 31 is configured to guide the mixture that has passed through the pair of rotors 33, 33 to the raw material inlet 21.

[0055] The charging mechanism 30 rotates the rotors 33 in opposite directions to entrain the mixture between the pair of rotors 33 and push the mixture into the raw material charging port 21. An example of the charging mechanism 30 will be specifically described below.

[0056] The dosing mechanism 30 rotates the rotors 33, 33, and moves the mixture in contact with the rotors 33, 33 in the rotation direction of the rotors 33, 33. If the rotors 33 have teeth 35, the mixture located above the pair of rotors 33, 33 is scraped off by the teeth 35 and moved in the rotation direction of the rotors 33, 33.

[0057] The feeding mechanism 30 entrains the mixture, which moves as the rotors 33, 33 rotate, between the pair of rotors 33, 33, and passes the mixture between the pair of rotors 33, 33. The polyurethane resin may be compressed as the mixture passes between the pair of rotors 33, 33. The polyurethane resin may also be pulverized as the mixture passes between the pair of rotors 33, 33. If the mixture is in the form of clumps, the clumps can be broken down as the mixture passes between the pair of rotors 33, 33. A configuration in which the mixture passes between the pair of rotors 33, 33 allows the polyurethane decomposition composition to be more effectively distributed over the pulverized polyurethane resin than a configuration in which the mixture does not pass between the pair of rotors 33, 33.

[0058] The feeding mechanism 30 sequentially sends the mixture entrained between the pair of rotors 33, 33 toward the raw material inlet 21 and pushes it into the raw material inlet 21. The mixture pushed into the raw material inlet 21 is transferred within the cylinder 20 toward the discharge outlet 23 as the screw 11 rotates. The decomposition treatment device 1 can sequentially pass the mixture through the pair of rotors 33, 33 and transfer it from the raw material inlet 21 to the discharge outlet 23 by interlocking the pair of rotors 33, 33 with the screw 11.

[0059] (3) mixture The mixture can be obtained by appropriately mixing pulverized polyurethane resin and a polyurethane decomposition composition. The mixture can be obtained, for example, by applying the polyurethane decomposition composition to pulverized polyurethane resin. The method for applying the polyurethane decomposition composition to pulverized polyurethane resin is not particularly limited. For example, the polyurethane decomposition composition may be sprayed onto the pulverized polyurethane resin. For example, pulverized polyurethane foam may be transported by a transport means such as a conveyor, and the polyurethane decomposition composition may be sprayed onto the pulverized polyurethane foam during transport, and then directly placed into the feeding mechanism 30. Alternatively, the pulverized polyurethane resin and the polyurethane decomposition composition may be placed in a container such as a bag, and the contents may be stirred within the container to apply the composition.

[0060] The pulverized polyurethane resin is not particularly limited. The polyurethane resin may be polyurethane foam. The polyurethane foam may be any of rigid polyurethane foam, semi-rigid polyurethane foam, and flexible polyurethane foam. The polyurethane foam may be an open-cell polyurethane foam or a closed-cell polyurethane foam. In this embodiment, an embodiment in which the polyurethane resin is a pulverized product that has been pulverized in advance before being treated in the dosing mechanism 30 will be described. Note that the polyurethane resin may not be pulverized in advance before being treated in the dosing mechanism 30, but may be pulverized by the dosing mechanism 30 to form a pulverized product. The polyurethane resin may be, for example, scraps discarded during the polyurethane foam manufacturing process or used polyurethane foam that is to be discarded.

[0061] 7. Method for decomposing polyurethane resin using decomposition treatment device 1 The method for decomposing a polyurethane resin preferably uses a decomposition treatment device 1 equipped with an extruder 10 having the above-mentioned cylinder 20. In this case, the method for decomposing a polyurethane resin involves forcing a mixture of pulverized polyurethane resin and a composition for decomposing polyurethane into the raw material inlet 21 of the cylinder 20, and heating the mixture while transporting it within the cylinder 20, thereby decomposing the polyurethane resin.

[0062] The residence time for which the mixture remains in the cylinder 20 is not particularly limited. The residence time may be, for example, from 0.5 minutes to 5 hours, or from 1 minute to 10 minutes. The residence time can be changed by adjusting the rotation speed of the screw 11. The residence time may be set appropriately depending on the time required for decomposition of the polyurethane resin. [Example]

[0063] 1. Polyurethane foam manufacturing A polyurethane foam composition (liquids A and B) was prepared in the proportions shown in Table 1 for "polyurethane foam," and polyurethane foam (rigid foam) was produced by slab foaming. The details of each raw material are as follows: Polyol: Polyether polyol, hydroxyl value 56 mg KOH / g, product number GL3000, manufactured by Sanyo Chemical Industries, Ltd. Crosslinking agent: Ethylenediamine, manufactured by Mitsui Takeda Polyetheramine: Trimethylolpropane poly(oxypropylene)triamine, amine value 352.5 mg KOH / g, functionality 3, product number JEFFAMINE T-403, manufactured by HUNTSMAN Catalyst: Amine catalyst, PC-37, manufactured by EVONIC Foam stabilizer: SZ1136, manufactured by Toray Dow Corning Flame retardant: Tris(chloropropyl)phosphate (TCPP) Foaming agent: Water Isocyanate: Crude MDI, NCO% 31%

[0064] [Table 1]

[0065] 2.Decomposition of polyurethane foam The obtained polyurethane foam was pulverized in a pulverizer to obtain a pulverized polyurethane foam. The pulverized polyurethane foam and a polyurethane decomposition composition were mixed in the ratios shown in Table 2 to obtain a mixture. The polyurethane decomposition composition was diethylene glycol and an aromatic polyol in the examples, and diethylene glycol in the comparative examples. The aromatic polyols used were as follows: Aromatic polyol: Aromatic polyol derived from cashew nut shell liquid (polyol represented by the above structural formulas (1) and (2)), product name: NX5285 (manufactured by Cardrite Co., Ltd.), biomass ratio: 93%, average hydroxyl value: 180 mg KOH / g - 240 mg KOH / g, average viscosity (25°C): 1000 cps - 4000 cps, average functionality: 2.8, aromatic concentration: 21.5%

[0066] [Table 2]

[0067] The resulting mixture was decomposed using the decomposition treatment device (equipment equipped with a single-screw extruder) described in the embodiment. Specifically, the mixture was charged into the raw material charging port while being pushed using a charging mechanism. The mixture had a tendency to clump together more easily than the pulverized polyurethane foam alone. In this example, by using the charging mechanism, the pulverized polyurethane foam could be smoothly charged into the raw material charging port even in the form of a mixture.

[0068] The mixture was fed into the raw material inlet and heated while being transported in the cylinder to decompose the polyurethane foam. The heating temperature was 200°C and the residence time was 5 minutes.

[0069] 3. Results of decomposition treatment of polyurethane foam The appearance of the polyurethane decomposition product was visually observed. In Examples 1-4, a homogeneous liquid was produced as the polyurethane decomposition product (decomposition liquid). In contrast, in Comparative Example 1, a separated, non-homogeneous liquid was produced. The reason why a homogeneous liquid was produced in Example 1-4 is presumed to be as follows: The polyurethane foam to be decomposed contains a structure derived from aromatic isocyanate. Therefore, it is presumed that the decomposition products of the polyurethane foam contain compounds having aromatic rings derived from aromatic isocyanate. In Example 1-4, an aromatic polyol is used in the polyurethane decomposition composition, and therefore it is presumed that the affinity between this aromatic polyol and the compounds having aromatic rings in the decomposition products is high, resulting in the production of a homogeneous liquid.

[0070] 4. Manufacturing recycled polyurethane foam In Table 1, 2 parts by mass of the decomposition product obtained by the decomposition treatment was used as the polyetheramine. Otherwise, a recycled polyurethane foam composition (liquids A and B) was prepared in the same manner as in "1. Production of polyurethane foam." The temperatures of liquids A and B were adjusted to 10°C, and the mixture was stirred in a 1000 mL disposable cup. The mixture was then foamed in a 200 mm x 200 mm x 300 mm foam bag to produce a recycled polyurethane foam. When the decomposition products of Examples 1-4 were used, recycled polyurethane foams (rigid foams) with good appearance were produced. On the other hand, when the decomposition product of Comparative Example 1 was used, a recycled polyurethane foam (rigid foam) having defects on the surface was produced.

[0071] 5. Effects of the Example According to this example, a homogeneous liquid decomposition product that can be easily used as a recycled raw material can be obtained without purification, etc. Furthermore, according to this example, a recycled polyurethane foam with a good appearance can be obtained.

[0072] The present invention is not limited to the above-described embodiments and examples, and various modifications and variations are possible. [Explanation of symbols]

[0073] 1. Decomposition treatment equipment 10...Extruder 11...Screw 13...Drive unit 20...Cylinder 21...Raw material input port 23…Discharge port 25...Heating part 30...Insertion mechanism 31...Hopper 33...Rotor 35...tooth

Claims

1. A composition for decomposing polyurethane, comprising a first compound and a second compound, the first compound is polyethylene glycol; The composition for decomposing polyurethane, wherein the second compound is an aromatic polyol.

2. The polyurethane decomposition composition according to claim 1 , wherein the second compound has a plurality of benzene rings each having a phenolic hydroxyl group.

3. The polyurethane decomposition composition according to claim 1 or 2, wherein the second compound satisfies all of the following (i), (ii), and (iii): (i) Derived from cashew nut shells. (ii) The molecular weight is 500 or more. (iii) It has a phenolic hydroxyl group.

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

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

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