Method for decomposing composite materials and method for producing recycled polyol

Abstract

To provide a technique capable of decomposing a composite material comprising a polyester part and a polyurethane part and reducing an amine compound contained in a decomposition treatment liquid.SOLUTION: There is provided a method for decomposing a composite material comprising a polyester part and a polyurethane part, wherein the method comprises: decomposing the polyurethane part to produce a polyol; and reacting an amine compound produced by decomposition of the polyurethane part with a dicarboxylic acid produced by decomposition of the polyester part.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to a method for decomposing a composite material and a method for producing recycled polyol. [Background technology]

[0002] Patent Document 1 describes a method for producing recycled polyol from polyurethane foam. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-246568 A Summary of the Invention [Problem to be solved by the invention]

[0004] Although the decomposition treatment of polyurethane has been studied, the decomposition treatment of composite materials having polyester and polyurethane parts has not been sufficiently studied. Also, a technology for removing amine compounds generated by the decomposition of polyurethane from the decomposition treatment solution is desired.

[0005] The present disclosure has been made in view of the above circumstances, and aims to provide a technique capable of decomposing a composite material having a polyester portion and a polyurethane portion, and reducing an amine compound contained in a decomposition treatment liquid. The present disclosure can be realized in the following forms. [Means for solving the problem]

[0006] [1] A method for decomposing a composite material having a polyester portion and a polyurethane portion, comprising the steps of: decomposing the polyurethane portion to generate a polyol; The method for decomposing a composite material comprises reacting an amine compound produced by decomposition of the polyurethane portion with a dicarboxylic acid produced by decomposition of the polyester portion. [2] The method for decomposing a composite material according to [1], further comprising precipitating a reaction product of the dicarboxylic acid and the amine compound in a solution for decomposing the composite material. [3] The method for decomposing a composite material according to [1] or [2], further comprising using a decomposing agent that decomposes the polyester portion and also decomposes the polyurethane portion. [4] The method for decomposing a composite material according to [3], wherein the decomposing agent is at least one selected from the group consisting of potassium octylate, diethanolamine, 2-[[2-(dimethylamino)ethyl]methylamino]ethanol, diazabicycloundecene, and salts of diazabicycloundecene. [5] A method for producing a recycled polyol by decomposing a composite material having a polyester portion and a polyurethane portion and recovering the resulting polyol, comprising: decomposing the polyurethane portion to generate a polyol; A method for producing a recycled polyol, comprising reacting an amine compound produced by decomposition of the polyurethane portion with a dicarboxylic acid produced by decomposition of the polyester portion. Effect of the Invention

[0007] According to the present disclosure, it is possible to provide a technology capable of decomposing a composite material having a polyester portion and a polyurethane portion and reducing the amount of amine compounds contained in the decomposition treatment liquid. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] 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.

[0009] 1. Methods for decomposing composite materials The method for decomposing a composite material is a method for decomposing a composite material having a polyester portion and a polyurethane portion. The method for decomposing a composite material includes decomposing the polyurethane portion to generate a polyol, and reacting an amine compound generated by decomposing the polyurethane portion with a dicarboxylic acid generated by decomposing the polyester portion.

[0010] 1.1 Composite materials The composite material includes a polyester part and a polyurethane part. The shape of the composite material and the configuration of the polyester part and the polyurethane part are not particularly limited. For example, the composite material may be configured such that a layered polyester part is provided on the surface of the polyurethane part, or may be configured such that a layered polyurethane part is provided on the surface of the polyester part. The composite material may be a laminate including a layered polyester part and a layered polyurethane part. When the polyester part and / or the polyurethane part are configured in layers, it is difficult to separate the polyester part and the polyurethane part by means of cutting or the like, and the technology of the present disclosure is particularly effective. The composite material may be, for example, offcuts generated during the manufacturing process of a product, or a post-consumer product destined for disposal.

[0011] The mass ratio of the polyester part to the polyurethane part in the composite material is not particularly limited. From the viewpoint of obtaining a sufficient amount of recycled polyol while ensuring the production amount of dicarboxylic acid, the mass ratio of the polyester part to the polyurethane part (polyester part: polyurethane part) is preferably 1:99-80:20, more preferably 2:98-60:40, and even more preferably 5:95-30:70.

[0012] The polyester constituting the polyester portion 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).

[0013] The polyurethane constituting the polyurethane portion may be foamed or non-foamed. The polyurethane foam may be any of soft polyurethane foam, semi-rigid polyurethane foam, and rigid polyurethane foam. Examples of polyurethane include polyether-based polyurethane made from polyether polyol, polyester-based polyurethane made from polyester polyol, and polycarbonate-based polyurethane. Among these, polyether-based polyurethane is preferred because it can be used to obtain a recycled polyol that is the same as the polyol derived from the raw material.

[0014] 1.2 Decomposition Agent It is preferable to use a decomposing agent for the decomposition treatment of the composite material. However, in cases where the composite material itself contains a compound that acts as a decomposing agent, or where moisture in the treatment atmosphere acts as a decomposing agent, it is not necessary to add a decomposing agent.

[0015] The decomposing agent is preferably a decomposing agent that decomposes the polyester portion and also decomposes the polyurethane portion. The decomposing agent that decomposes the polyester portion has a property that acts on the decomposition reaction of the ester bond. The decomposing agent that decomposes the polyurethane portion has a property that acts on the decomposition reaction of the urethane bond. Examples of the reaction that is the decomposition reaction of the ester bond and is the decomposition reaction of the urethane bond include hydrolysis, aminolysis, and glycolysis. In these reactions, the decomposing agent may act as a decomposition catalyst, or may itself act as a reactant. Only one type of decomposing agent may be used, or two or more types may be used.

[0016] The present inventors have conducted extensive research and found that in a composite material, a decomposer that decomposes a polyester portion also has the effect of decomposing a polyurethane portion. However, a decomposer that decomposes a polyurethane portion does not necessarily have the effect of decomposing a polyester portion. In other words, a decomposer that decomposes a polyester portion and also decomposes a polyurethane portion is preferably a decomposer that has the effect of hydrolyzing an ester bond or a decomposer that causes an ester exchange reaction. Examples of such decomposition agents include one or more selected from the group consisting of potassium octylate, diethanolamine, 2-[[2-(dimethylamino)ethyl]methylamino]ethanol, diazabicycloundecene, and salts of diazabicycloundecene. Note that 2-[[2-(dimethylamino)ethyl]methylamino]ethanol is a compound represented by the following formula (1). [ka]

[0017] The amount of the decomposition agent added is not particularly limited, and is preferably 0.1 parts by mass or more and 200 parts by mass or less, more preferably 0.4 parts by mass or more and 100 parts by mass or less, and even more preferably 0.8 parts by mass or more and 50 parts by mass or less, relative to 100 parts by mass of the composite material.

[0018] 1.3 An example of decomposition processing The method for decomposing the composite material involves decomposing the polyurethane portion to produce a polyol, and reacting an amine compound produced by decomposition of the polyurethane portion with a dicarboxylic acid produced by decomposition of the polyester portion.

[0019] Polyurethane is decomposed into polyol and amine compounds by decomposition treatment. Examples of amine compounds include amine compounds derived from the raw material isocyanate of polyurethane, and derivatives thereof. That is, for example, when MDI (diphenylmethane diisocyanate) is used as the raw material isocyanate, amine compounds such as MDA (methylenedianiline) and its derivatives are generated.

[0020] The polyester is decomposed into dicarboxylic acid and diol by the decomposition process. For example, when the polyester is polyethylene terephthalate, it is decomposed into terephthalic acid and ethylene glycol. The dicarboxylic acid acts as a remover for amine compounds. The diol acts as a decomposer for polyurethane. In addition, since the diol can generate urethane bonds, it can also be used as a recycled raw material. Therefore, the decomposition products of polyester have very little adverse effect on the reuse of the decomposition products of polyurethane foam.

[0021] Usually, when an amine compound and a dicarboxylic acid are mixed, a salt of the amine compound and the dicarboxylic acid is produced. In order to react an amine compound produced by decomposing a polyurethane part with a dicarboxylic acid produced by decomposing a polyester part, for example, a dicarboxylic acid and an amine compound may be mixed in a decomposition treatment liquid of a composite material. That is, if a composite material is decomposed under treatment conditions in which the polyurethane part is decomposed and the polyester part is decomposed, the dicarboxylic acid and the amine compound are mixed in the decomposition treatment liquid of the composite material, and a salt of the amine compound and the dicarboxylic acid can be produced. Note that the reaction product obtained by reacting an amine compound and a dicarboxylic acid is not limited to a salt of an amine compound and a dicarboxylic acid, but may be an amide compound or the like.

[0022] In one example of a method for decomposing a composite material, the composite material and, if necessary, a decomposing agent are placed in a container and maintained at a predetermined treatment temperature. The treatment temperature is preferably 120° C. or higher and 250° C. or lower, and more preferably 170° C. or higher and 230° C. or lower. A decomposition treatment liquid for the composite material is then retained in the container, and an amine compound produced by decomposition of the polyurethane portion and a dicarboxylic acid produced by decomposition of the polyester portion are mixed in the decomposition treatment liquid for the composite material, and the dicarboxylic acid and the amine compound are reacted with each other.

[0023] In the method of decomposing the composite material, the reaction product of the dicarboxylic acid and the amine compound is precipitated in the decomposition treatment liquid of the composite material, because the generated polyol (regenerated polyol) and the reaction product of the dicarboxylic acid and the amine compound can be easily separated. "Precipitating the reaction product of the dicarboxylic acid and the amine compound" means precipitating at least a part of the reaction product of the dicarboxylic acid and the amine compound. The precipitation of the reaction product of the dicarboxylic acid and the amine compound can be confirmed by the fact that the total amine value of the decomposition treatment liquid obtained by decomposing the composite material and removing the precipitate is lower than the total amine value of the decomposition treatment liquid obtained by decomposing only the polyurethane foam portion and removing the precipitate.

[0024] The decomposition liquid may be obtained in a single phase state, or may be obtained in a phase-separated state with an upper phase containing at least a polyol and a lower phase containing at least an amine compound. If the decomposition liquid is in a phase-separated state, it is preferable because it is easy to separate the polyol derived from the polyurethane part and the reaction product of the dicarboxylic acid and the amine compound. In order to obtain the decomposition product of the polyurethane resin in a phase-separated state, the type of decomposition agent, the amount of the decomposition agent, etc. may be appropriately adjusted.

[0025] The composite decomposition liquid may be used as a recycled raw material, or may be disposed of partially or entirely as waste. The amine compound may include, for example, a carcinogenic substance such as MDA. According to the composite decomposition method of the present embodiment, the amine compound in the decomposition liquid is easily separated as a reaction product. Therefore, whether it is used as a recycled raw material or disposed of as waste, the amine compound is easily removed, and the safety during handling can be improved. In addition, when a recycled polyol is recovered from the decomposition liquid, the amine value of the recycled polyol can be reduced, and the reactivity of the recycled polyol can be suitably controlled.

[0026] 2. Manufacturing method of recycled polyol The method for producing recycled polyol involves decomposing a composite material having a polyester portion and a polyurethane portion, recovering the resulting polyol, and producing recycled polyol. The method for producing recycled polyol involves decomposing the polyurethane portion to produce a polyol, and reacting an amine compound produced by decomposing the polyurethane portion with a dicarboxylic acid produced by decomposing the polyester portion. In the method for producing recycled polyol, the explanations for an example of the composite material, decomposition agent, and decomposition treatment in the section "1. Decomposition treatment method for composite material" in "1.1 Composite material," "1.2 Decomposition agent," and "1.3 Example of decomposition treatment" apply as is, and the description thereof is omitted.

[0027] In the method for producing the recycled polyol, the composite material is decomposed as described above, and the resulting polyol is recovered. The recovered polyol can be purified by a known method, or can be used as the recycled polyol as it is.

[0028] The method of recovering the polyol is not particularly limited. The reaction product of the dicarboxylic acid and the amine compound usually exists as a solid in the decomposition treatment liquid, so for example, the decomposition treatment liquid can be filtered to separate and recover the polyol from the reaction product of the dicarboxylic acid and the amine compound. Alternatively, the decomposition treatment liquid may be in a phase-separated state, and only the upper phase containing at least the polyol may be scooped or decanted and recovered. In this way, the reaction product of the dicarboxylic acid and the amine compound that precipitates and exists in the lower phase can be suitably separated from the polyol.

[0029] 3. Effects of this embodiment The composite material decomposition method and the method for producing recycled polyol of this embodiment can decompose a composite material having a polyester portion and a polyurethane portion as it is. Conventionally, a technique for decomposing polyurethane and a technique for decomposing polyester have been reported, but a technique for decomposing a composite material having a polyester portion and a polyurethane portion as it is is not known. If the polyester portion and the polyurethane portion are separated in advance by a means such as cutting and then decomposed, it takes time and effort to separate the polyester portion and the polyurethane portion. In addition, it is difficult to completely separate the polyester portion and the polyurethane portion. On the other hand, according to this embodiment, the time and effort required for separating the polyester portion and the polyurethane portion can be saved.

[0030] The amine compound mixed into the polyol may affect the use of the polyol as a recycled polyol, etc. For this reason, it is desirable to reduce the amine value of the resulting polyol. The composite material decomposition treatment method and the recycled polyol production method of the present embodiment react an amine compound generated by decomposing the polyurethane part with a dicarboxylic acid generated by decomposing the polyester part, so that the amine value of the resulting polyol can be reduced. EXAMPLES

[0031] 1. Screening of decomposition agents A laminate having a layered polyester portion and a layered polyurethane portion was prepared as a composite material having a polyester portion and a polyurethane portion. The laminate having a thickness of 2.5 mm was cut into a size of 30 mm x 30 mm to prepare a sample. <Composite material> Rogers Inoac PORON, product number SR-S, thickness 2.5mm Polyurethane section: Polyether polyurethane foam Polyester section: Polyethylene terephthalate sheet Polyurethane part: polyester part = 8:92 (mass ratio) The blend ratio of polyurethane raw materials and composite raw materials when the total is 100 parts by mass Polyol Polyether polyol 56 parts by mass Isocyanate MDI 22 parts by weight Other ingredients: 14 parts by weight

[0032] The decomposition agent shown in Table 1 was placed in an aluminum cup container, and the sample was placed with the polyester part facing up. The amount of decomposition agent was 50 parts by mass per 100 parts by mass of the sample. The container containing the decomposition agent and the sample was placed on a hot plate heated to 200°C and left to stand for 5 hours. After that, it was returned to room temperature, and the decomposition state of the sample was visually confirmed.

[0033] [Table 1]

[0034] 2. Results of decomposition agent screening The decomposition agents were visually evaluated according to the following criteria, and the results are shown in Table 1. <Degradability of polyurethane part> "Decompose": Some or all of the polyurethane part remains. "Does not decompose": All polyurethane parts remain. <Degradability of polyester part> "Decompose": Some or all of the polyester portion remains. "Does not decompose": The entire polyester portion remains. <Evaluation> "OK": Both the polyurethane part and the polyester part are "decomposable". "Not decomposable": Either the decomposability of the polyurethane part or the decomposability of the polyester part is "not decomposable."

[0035] Of the decomposition agents listed in Table 1, it was found that the composite materials could be decomposed when potassium octylate, diethanolamine, 2-[[2-(dimethylamino)ethyl]methylamino]ethanol, diazabicycloundecene (DBU), and a salt of diazabicycloundecene (DBU-phenol salt) were used.

[0036] 3. Decomposition of composite materials and production of recycled polyol In the example, the same composite material as in "1. Screening of decomposers" was cut into a 40 mm x 40 mm sample. In the comparative example, only the polyurethane portion was cut into a 40 mm x 40 mm sample from the composite material. That is, the blending ratio of the raw materials in the comparative example was 61 parts by mass of polyol (polyether polyol), 24 parts by mass of isocyanate (MDI), and 15 parts by mass of other components, assuming that the entire raw materials of the sample were 100 parts by mass.

[0037] Diazabicycloundecene (DBU) and the sample were placed in a flask, heated to 210°C, and heated for 5 hours. The amount of diazabicycloundecene was 1 part by mass per 100 parts by mass of the sample. After heating, the temperature was returned to room temperature, and the decomposition product was filtered. A black solid was obtained as the residue. This solid contains a reaction product between an amine compound produced by decomposition of the polyurethane portion and a dicarboxylic acid produced by decomposition of the polyester portion. In addition, a brown decomposition treatment liquid was collected as the filtrate. This decomposition treatment liquid contains a polyol obtained by decomposing the polyurethane portion. In other words, a regenerated polyol was produced as the decomposition treatment liquid.

[0038] The following analyses were carried out on the recovered decomposition liquid, the results of which are shown in Table 2. Total amine value Measurements were performed in accordance with JIS K 1557-4. Hydroxyl value Measurements were performed in accordance with JIS K 1557-1. Acid number Measurements were performed in accordance with JIS K 1557-5. ·viscosity The measurements were performed at a shear rate of 0.1 (1 / s) using a cone-plate rotational viscometer in accordance with JIS K1557-5, Section 6.2.3. ·Number average molecular weight (Mn), weight average molecular weight (Mw) This is a value calculated in terms of polystyrene measured by gel permeation chromatography (GPC). MDA The amount of MDA (ppm) in the decomposition solution was measured by liquid chromatography mass spectrometry (LC-MC).

[0039] [Table 2]

[0040] 4. Results of decomposition of composite materials and production of recycled polyol The total amine value of the Example was 28.9 KOHmg / g. In contrast, the total amine value of the Comparative Example was 58.6 KOHmg / g. It was found that the Example had a lower total amine value than the Comparative Example. This is presumably because the amount of the amine compound in the recovered decomposition treatment liquid was reduced by separating the reaction product of the amine compound produced by decomposition of the polyurethane portion and the dicarboxylic acid produced by decomposition of the polyester portion.

[0041] The amount of MDA in the decomposition treatment liquid of the Example was 7631 ppm. In contrast, the amount of MDA in the decomposition treatment liquid of the Comparative Example was 19407 ppm. It was found that the amount of MDA in the Example was less than that in the Comparative Example. This is presumably because the amount of MDA in the recovered decomposition treatment liquid was reduced by separating the reaction product between MDA, an amine compound produced by decomposition of the polyurethane portion, and dicarboxylic acid produced by decomposition of the polyester portion.

[0042] 5. Effects of the embodiment According to this embodiment, a technique was provided that can decompose a composite material having a polyester portion and a polyurethane portion and reduce the amount of amine compounds contained in the decomposition treatment liquid.

[0043] The present disclosure is not limited to the above-described embodiments, and various modifications and variations are possible.

Claims

1. A method for decomposing a composite material having a polyester portion and a polyurethane portion, comprising the steps of: decomposing the polyurethane portion to generate a polyol; The method for decomposing a composite material comprises reacting an amine compound produced by decomposition of the polyurethane portion with a dicarboxylic acid produced by decomposition of the polyester portion.

2. 2. The method for decomposing a composite material according to claim 1, further comprising precipitating a reaction product of the dicarboxylic acid and the amine compound in a solution for decomposing a composite material.

3. 3. The method for decomposing a composite material according to claim 1, further comprising using a decomposing agent which decomposes the polyester portion and also decomposes the polyurethane portion.

4. The method for decomposing a composite material according to claim 3, wherein the decomposing agent is at least one selected from the group consisting of potassium octylate, diethanolamine, 2-[[2-(dimethylamino)ethyl]methylamino]ethanol, diazabicycloundecene, and salts of diazabicycloundecene.

5. A method for producing a recycled polyol by decomposing a composite material having a polyester portion and a polyurethane portion and recovering the resulting polyol, comprising: decomposing the polyurethane portion to generate a polyol; A method for producing a recycled polyol, comprising reacting an amine compound produced by decomposition of the polyurethane portion with a dicarboxylic acid produced by decomposition of the polyester portion.

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