KR102661077B1 - Recycling method of waste polymer materials blended with polymer containing ester functional groups and polymer containing urethane functional groups - Google Patents

Abstract

The present invention relates to polymer regeneration of a mixed material containing both a polymer containing an ester functional group and a polymer containing a urethane functional group, wherein the polymer of the mixed material contains at least one aromatic compound having one or more alkoxy functional groups. By sequentially or simultaneously contacting a second compound containing at least one of the first compound and a compound having one or more alcohol functional groups to selectively dissolve, filter, and separate the polymer containing the urethane functional group in the composite polymer, the separated urethane functional group It relates to a method for regenerating a polymer of a mixed material containing both a polymer containing an ester functional group and a urethane functional group, characterized in that the polymer containing a polymer and a polymer containing an ester functional group can be separately depolymerized.

Description

{Recycling method of waste polymer materials blended with polymer containing ester functional groups and polymer containing urethane functional groups}

In the present invention, in regenerating a mixed polymer material in which a polymer containing an ester functional group and a polymer containing a urethane functional group are mixed, only the polymer containing a urethane functional group is selectively dissolved and extracted from the mixed polymer material. , a mixture of a polymer containing an ester functional group and a polymer containing a urethane functional group, characterized in that the polymer containing a urethane functional group and the polymer containing an ester functional group are separated from the polymer of the mixed material and depolymerized separately. This relates to a method of chemically regenerating mixed polymer materials.

Polymers synthesized using raw materials extracted from petroleum are inexpensive and durable materials, and have the advantage of being easy to mold and process, so they are used to produce various products such as synthetic fibers and plastics. Due to these advantages, the consumption of products using the above synthetic polymers has increased dramatically over several decades in various fields of life. However, synthetic polymer waste that has not been properly managed after consumption is being disposed of in non-environmental ways, causing various environmental problems. Some of it is left in the environment through methods such as landfilling, and then decomposes into small pieces and wanders throughout the ecosystem. It is known that it accumulates in living organisms and can eventually be reabsorbed into the body through fine dust, drinking water, food, etc., posing a direct threat to human health and the living environment.

To solve these problems, we are working to minimize the accumulation of plastics or reduce their environmental impact, from chemical decomposition of existing petroleum-based plastics to physical recycling and reprocessing of plastics, including the development of new plastic materials with a short decomposition cycle in nature. Various research and efforts are being attempted. However, material or physical recycling, which involves reusing the polymer material itself after washing or modifying only some of its forms or characteristics, is known to have limited uses and number of recycling due to difficulties in managing physical properties or quality. On the other hand, the depolymerization method, which chemically decomposes waste synthetic polymer products discharged after use, can produce monomers corresponding to the raw materials before synthesis, and even through repeated recycling processes, products of equal or similar quality to the initial materials can be produced. Since it can be reproduced, it is receiving a lot of attention as a realistic technology for establishing a resource recycling system.

Polymers have different decomposition characteristics depending on the type, and the types and properties of products produced from decomposition are also different. In order to recycle polymer products made of mixed materials containing two or more types of polymers, they must be classified as single substances with uniform polymer structural characteristics. The process must take precedence. In particular, waste fibers discharged after consumption are often a mixture of various types of fibers or are discharged as mixed materials. In order to recycle them, a pretreatment process and each step such as screening, separation, and removal of foreign substances for each polymer in the waste fibers is required. A series of recycling methods that can effectively decompose or process the separated materials are needed.

Recently, the development and related markets of functional textile materials have grown, and in particular, the textile market based on polyurethane materials called spandex, Elastan, Lycra, etc. has also grown explosively. The polyurethane material is called variously, such as Elaspan, Acepora, Creora, INVIYA, ROICA, and Dorlastan, depending on the manufacturer.

The polyurethane fibers not only have excellent elasticity but also have excellent bioadhesiveness, completely replacing existing rubber materials. In order to increase functionality, blended fibers spun together with other synthetic fibers are much better than materials composed of a single material. It is widely used. The above-mentioned blended fibers are difficult to separate each of the constituent materials separately using generally known simple separation techniques or physical sorting processes, making recycling of mixed waste fibers discharged after consumption more difficult.

For example, when depolymerization is performed simultaneously without separating each polymer from a material that is a mixture of a polymer with an ester functional group, such as a PET-based plastic material or polyester fiber, and a polymer with a urethane functional group, such as polyurethane, the polymer Not only does the depolymerization efficiency of each compound significantly decrease due to the different appropriate depolymerization conditions for each compound, but also products that are a mixture of the depolymerization products of each polymer from depolymerization, for example, BHET, which is a depolymerization product of a polymer with an ester functional group, and a polymer with a urethane functional group, Complex products are produced in the form of a mixture of various oligomers other than polyol, which is a monomer, and the purification process of removing some of these or re-separating only useful monomers and purifying them to a high level may require high energy, and the purification technology itself has many limitations. It can exist.

Japanese Patent Laid-Open No. 2014-058476 discloses the raw material components constituting polymers such as bishydroxyterephthalate, terephthalic acid, and dimethyl terephthalate from polyester waste containing polyalkylene terephthalate containing polyurethane as a main component in relatively high yield. Regarding the manufacturing method, it is claimed that the total concentration of isocyanate groups and amino groups is controlled to 1000 ppm or less by diluting or washing the mixture after the depolymerization reaction, but polyurethane itself is separately prepared from waste raw materials. It does not describe how to separate or recycle it.

In addition, Japanese Patent Laid-Open No. 2011-231279 discloses that polyurethane is made from a material that does not consist only of polyurethane, that is, a mixed material in which a polypropylene sheet that does not decompose by depolymerization is bonded or fixed together with a polyurethane layer as the base. A method of swelling, decomposition, dissolution, or peeling is used to provide a method of separating the substrate without decomposition products of polyurethane remaining in or mixing with the substrate. This is a recycling method of the substrate aimed at removing polyurethane. As a method of removing polyurethane, a solution of a solvent having a boiling point of 150°C or higher mixed with carbonate or phosphate of an alkali metal is added to remove the polyurethane layer from the substrate. Methods for disassembly and removal are proposed. This is limited to a method of removing polyurethane from a material that can be separated, that is, a homopolymer resin that does not decompose even when exposed to depolymerization conditions, because there is a significant difference in reactivity of each material even if the materials are mixed together. In other words, it can only be applied to mixtures that can only be classified into those that are reactive and those that are not. This applies to blended fibers such as polyurethane and polyester, where depolymerization and decomposition can occur simultaneously, or to materials that are a mixture of two or more reactive polymers. This is a method that cannot be applied.

The technologies known in the prior patent literature may have limited industrial use value because the range of waste polymer materials that can be recycled may be limited and the quality or performance of products manufactured according to the technology may not be significant.

On the other hand, the present applicant selectively dissolves and extracts only polymers containing urethane functional groups from polymers of mixed materials such as blended fibers containing both polymers containing ester functional groups and polymers containing urethane functional groups, thereby producing polymers with different chemical properties. A method was devised to separate or isolate them from each other.

In addition, polymers containing urethane functional groups and polymers containing ester functional groups separated from mixed waste polymers or waste fibers could be used as raw materials for depolymerizing each polymer without separate purification or washing processes, even if kept at low temperature. The present invention was completed by chemically decomposing each constituent polymer by applying a simple and efficient low-temperature depolymerization method that rapidly decomposes, and experimentally verifying that high-purity, high-yield recycled raw materials (or monomers) can be produced therefrom. It has reached.

Japanese Patent Publication No. 2014-058476 (2014.04.03.) Japanese Patent Publication No. 2011-231279 (2011.11.17.)

The present invention was created to recycle waste polymers of mixed materials that are difficult to use by known separation or decomposition methods. Polymers containing ester functional groups and polymers containing urethane functional groups are physically mixed with each other or fabricated or knitted. A composition for selectively separating polymers containing the urethane functional group by dissolving them from polymers of mixed materials that are a mixture of two or more types of polymers, such as blended materials produced to have a fiber structure, and a composition that can be recycled by chemically decomposing the polymers. The purpose is to provide a depolymerization method capable of producing monomers.

In addition, the present invention uses the composition to selectively dissolve only the polymer containing a urethane functional group in a polymer material in the form of a mixture of a polymer containing an ester functional group and a polymer containing a urethane functional group, and then separate the polymers containing a single polymer. The purpose is to provide a method for chemical recycling of waste polymers of mixed materials that can produce high-purity depolymerization products by forming reactants and applying a depolymerization reaction to them.

In addition, the present invention selectively dissolves only the polymer containing a urethane functional group from a waste polymer material that is a mixture of a polymer containing an ester functional group and a polymer containing a urethane functional group, and performs depolymerization by further adding a catalyst. A chemical method that can efficiently produce raw materials before synthesis by decomposing the waste polymer of the mixed material by separately depolymerizing only the polymer containing the ester functional group among the solid phase separated through filtration from the waste polymer of the mixed material. The purpose is to provide a recycling method.

In order to solve the above problems, the present invention provides a first compound comprising at least one aromatic compound having one or more alkoxy functional groups; And a second compound containing at least one of the compounds having one or more alcohol functional groups; urethane in the polymer as a mixed material containing both a polymer containing an ester functional group and a polymer containing a urethane functional group. A composition for selectively dissolving a polymer containing a functional group is provided.

In one embodiment of the composition of the present invention, the weight ratio of the first compound/second compound may be 0.01 to 100, and the polymer of the mixed material may be a polymer selected from cotton, cellulose, polyethylene, polypropylene, and nylon. More may be included.

In addition, the present invention provides a first compound containing at least one aromatic compound having one or more alkoxy functional groups and a second compound containing at least one compound having one or more alcohol functional groups in the polymer of the mixed material. Characterized in that the polymer containing a urethane functional group in the polymer of the mixed material is selectively dissolved by sequentially or simultaneously contacting the polymer, comprising both a polymer containing an ester functional group and a polymer containing a urethane functional group. A method for selectively dissolving a polymer containing a urethane functional group in a polymer of mixed materials is provided.

In the method of selectively dissolving a polymer containing a urethane functional group of the present invention, the temperature range for selective dissolution of the polymer containing a urethane functional group may be 100 to 180° C., and the sequential contact includes contacting the first compound first and , and then contacting the second compound.

In addition, in one embodiment of the method for selectively dissolving the polymer containing the urethane functional group, the mass of the first compound is in the range of 0.1 to 1000 times compared to the mass of the polymer of the mixed material, and the mass of the first compound/second compound is The weight ratio may be 0.01 to 100.

In addition, the present invention provides (a) a first compound comprising at least one aromatic compound having one or more alkoxy functional groups in a mixed polymer containing both a polymer containing an ester functional group and a polymer containing a urethane functional group; sequentially or simultaneously contacting a second compound containing at least one of the compounds having an alcohol functional group to selectively dissolve a polymer containing a urethane functional group in the polymer of the mixed material;

(b) filtering the mixed solvent of the first compound and the second compound in which the polymer containing the urethane functional group was dissolved after the selective dissolution, to obtain a polymer containing an ester functional group and a polymer containing a urethane functional group from the polymer of the mixed material. separating; and (c) separately depolymerizing the polymer containing the separated ester functional group and the polymer containing the urethane functional group; comprising both the polymer containing the ester functional group and the polymer containing the urethane functional group. A method for recycling polymers of mixed materials is provided.

In the polymer regeneration method of mixed materials of the present invention, the depolymerization of the polymer containing a urethane functional group in step (c) is performed by adding a catalyst for polymer depolymerization containing a urethane functional group to the filtered filtrate in step (b). It may be characterized in that the catalyst for polymer depolymerization containing the urethane functional group is alkali hydroxide, alkaline earth hydroxide, alkaline acetate, alkaline earth acetate, alkali carbonate, alkaline bicarbonate, alkaline earth carbonate, and alkali oxide. metal catalyst; or a guanidine-based or amine-based organic compound; and the depolymerization of the polymer containing the urethane functional group may be carried out in a temperature range of 100 to 170°C.

In addition, in the method for recycling polymers of mixed materials of the present invention, in step (c), the depolymerization of the polymer containing the ester functional group is carried out by hydrolysis, glycolysis, and methanolysis. Depolymerization can be performed using one or more of , ethanollysis, and ammonolysis.

The present invention allows extraction by selectively dissolving only the polymer containing the urethane functional group from waste polymers of which all or part of the components include a polymer containing an ester functional group and a polymer containing a urethane functional group, thereby producing a simple and efficient polymer material. Provides a separation method.

Mixed material: The compound composed for separation of waste polymers is a mixture of a first compound containing at least one aromatic compound having one or more alkoxy functional groups and a second compound containing at least one compound having one or more alcohol functional groups. It is effective by doing so, and it is advantageous to link it with the pretreatment process of mixed material waste polymers, which can remove dyes, pigments, and other hydrophobic organic and inorganic contaminants using only the first compound. For example, in the first process using only the first compound, organic foreign substances are removed, and in the second process, the second compound is added, thereby providing a method of extracting and separating only the polymer containing the urethane functional group from the waste polymer of the mixed material. You can. Depolymerization (alcoholosis-based) can be performed by adding only a depolymerization catalyst to the mixed solution from which the polymer containing the urethane functional group has been extracted, and a renewable polyol raw material can be obtained with high purity.

In addition, in regenerating the polymer of the mixed material, the present invention separates the polymer containing a urethane functional group and the polymer containing an ester functional group from the polymer of the mixed material and performs depolymerization, so that the polymer containing an ester functional group and the urethane Since the optimal conditions for efficient and rapid depolymerization can be designed differently for each polymer containing functional groups, the process can be designed so that the products obtained from the depolymerization of each polymer can be controlled at high quality and high yield, and each depolymerization product can be Since they do not mix with each other, the effect of minimizing unnecessary loss of energy and materials can be achieved even during the refining process.

In particular, the present invention can be used as a chemical recycling technology for materials in the form and material of a mixture of highly elastic polyurethane material and polyester, such as polyester blended fiber. Although the production and consumption of blended fibers is steadily increasing, the material itself is processed into a complex and difficult to separate state like fabric or knitted fabric, so most of the clothing discharged after use is disposed of through non-environmental methods such as landfill or incineration. Using the present invention, the blended fibers discharged after use can be chemically separated and depolymerized for each material with different characteristics, thereby returning them to the raw materials before synthesis. This not only increases the recycling rate of waste clothing, but also improves the recycling rate of clothing and fashion. It can also contribute to achieving a circular economy in industry.

Figure 1 is a conceptual diagram for explaining a method of recycling polyester and polyurethane blended fibers as an example of a mixed polymer containing a polymer containing an ester functional group and a polymer containing a urethane functional group according to an embodiment of the present invention. am.
Figure 1 is a conceptual diagram for explaining a method of recycling polyester and polyurethane blended fibers as an example of a mixed polymer containing a polymer containing an ester functional group and a polymer containing a urethane functional group according to an embodiment of the present invention. am.
Figure 2 shows selective dissolution of polyurethane by contacting a mixed polymer material with a first compound and a second compound according to Example 1, with contact times (a) 5 minutes, (b) 10 minutes, and (c) After 30 minutes and (d) 180 minutes, the shape of the mixed polymer material was observed under a stereomicroscope.
Figure 3 shows the chemical structure of polyester (raw material 2) and the location of protons in the polymer of the mixed material of raw material 1.
Figure 4 shows the chemical structure of polyurethane (raw material 3) and the location of protons in the polymer of the mixed material of raw material 1.
Figure 5 is a ¹ H-NMR spectrum measured for a mixed polymer material, a single polymer composing it, and a polymer separated according to the method of Example 1.
Figure 6 shows the IR spectrum for polyester and polyurethane polymers that can be separated from the mixed polymer material.
Figure 7 is a photograph showing the raw materials of the mixed polymer material in which colored foreign substances were previously removed from the colored polymer material of the mixed material by applying different temperatures of the first compound.
Figure 8 shows the chemical structure of the raw materials used to synthesize polyol or spandex obtained by separating polyurethane in the mixed polymer material and then depolymerizing it and the location of the proton.
Figure 9 shows ¹ H-NMR spectra measured for regenerated polyol obtained from depolymerization of separated polyurethane and polyol supplied from a reagent manufacturer.
Figure 10 shows the IR spectra for the recycled polyol obtained from the depolymerization of the separated polyurethane and the polyol supplied from the reagent manufacturer.

Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by a person skilled in the art to which the present invention pertains. In general, the nomenclature used herein is well known and commonly used in the art.

Throughout this specification, when a part “includes” a certain component, this means that it may further include other components rather than excluding other components, unless specifically stated to the contrary.

The present invention relates to a method of regenerating a mixed polymer material in which a polymer containing an ester functional group and a polymer containing a urethane functional group are mixed, by selectively dissolving only the polymer containing a urethane functional group in the mixed polymer. After filtering, the polymer containing the ester functional group and the polymer containing the urethane functional group are individually separated from the polymer of the mixed material, and the optimal depolymerization reaction conditions suitable for the type and characteristics of the polymer are applied to produce a high-purity, high-yield product. It relates to a method of recycling a polymer material that is a mixture of both a polymer containing an ester functional group and a polymer containing a urethane functional group, which can be obtained.

In the present invention, the polymer containing the urethane functional group is derived from a polyhydric alcohol (or polyol), and the molecular structure having a flexible structure and elastic recovery force and the molecular structure providing strong cohesion are manufactured into a high molecular weight structure by urethane bonding to each other. This material is also called polyurethane. The polymer containing a urethane functional group may be a polyurethane with soft or hard characteristics, and may be a foam-type polyurethane manufactured to have cells by foaming during production, or a non-form polyurethane mainly composed of a continuous polymer phase. There may also be material. Here, it may include polyethylene, high-density polyethylene, low-density polyethylene, polypropylene, polyethylene terephthalate, or a combination thereof, but is not limited to the types of polymers described above, and may be in the form of a mixture or copolymerization with other known polymers, Or, it may contain various types of organic and inorganic foreign substances.

As an example of a polymer containing the urethane functional group, polyurethane is a polymer in the form of a multiblock copolymer containing a urethane functional group, and has a rigid structure adjacent to the urethane bond that maintains strong cohesion and thermodynamic stability. It is composed of a hard segment (HS) and a soft segment (SS) that forms a chain of flexible polymers to have elasticity and can be a polymer with various types, shapes, and characteristics.

The part that constitutes the HS of the polyurethane may be made of various types of diisocyanate, but aromatic diisocyanate is the most common. Representative examples of aromatic diisocyanates that form HS through the synthesis of polyurethane include toluene diisocyanate (TDI), methylene diphenyl diisocyanate (MDI), and m-xylene diisocyanate (MXDI). , a polymer form that is easy to handle, such as polyisocyanate, may be used because it is easily soluble in the organic phase. SS, which constitutes the flexible polymer chain of the polyurethane, may be in the form of polyether polyol, polyester polyol, poly(tetramethylene ether) glycol (PTMEG) (or polytetrahydrofuran (PolyTHF)).

In addition, in the present invention, the polymer containing the ester functional group may be a polymer formed by condensation polymerization of dicarboxylic acid and dialcohol, where the dicarboxylic acid is terephthalic acid, naphthalene dicarboxylic acid, diphenyl dicarboxylic acid, and diphenyl dicarboxylic acid. Ether dicarboxylic acid, diphenylsulfone dicarboxylic acid, diphenoxyethane dicarboxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, decane dicarboxylic acid, cyclohexane dicarboxylic acid, tricarboxylic acid It is selected from the group consisting of mellitic acid, pyromellitic acid, and combinations thereof, and the dialcohol is ethylene glycol, trimethylene glycol, 1,2-propanediol, tetramethylene glycol, neopentyl glycol, hexamethylene glycol, decane methylene glycol, and dodecyl alcohol. Camethylene glycol, 1,4-cyclohexanedimethanol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, polypropylene glycol, di(tetramethylene) glycol , tri(tetramethylene)glycol, polytetramethylene glycol, pentaerythritol, 2,2-bis(4-β-hydroxyphenyl)propane, and combinations thereof.

For example, polymers containing the ester functional group include polyethylene terephthalate (PET), polypropylene terephthalate (PPT), polyglycolide or polyglycolic acid (PGA), polylactic acid (PLA), polycaprolactone (PCL), Polyhydroxyalkanoate (PHA), polyhydroxybutyrate (PHB), polyethylene adipate (PEA), polybutylene succinate (PBS), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) ) (PHBV), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), Vectran, and combinations thereof.

Meanwhile, in the present invention, the polymer of the mixed material may further include natural or synthetic polymers such as cotton, cellulose, polypropylene, polyethylene, and nylon, in addition to polymers containing ester functional groups and polymers containing urethane functional groups.

Hereinafter, with reference to the attached drawings, a detailed description will be given of a method for regenerating a polymer of a mixed material in which a polymer containing an ester functional group and a polymer containing a urethane functional group are mixed according to an embodiment of the present invention.

In order to regenerate a polymer of a mixed material in which a polymer containing an ester functional group and a polymer containing a urethane functional group are part or all of the components according to an embodiment of the present invention, a polymer containing a urethane functional group in the polymer of the mixed material is used. A selectively dissolving composition is used, comprising: a first compound comprising at least one aromatic compound having one or more alkoxy functional groups; and a second compound comprising at least one of a compound having one or more alcohol functional groups.

The first compound is methoxybenzene, ethoxybenzene, butoxybenzene, 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, 1,4-dimethoxybenzene, 1,2-diethoxybenzene, 1 ,3-diethoxybenzene, 1,4-diethoxybenzene, 1,2,3-trimethoxybenzene, 1,2,4-trimethoxybenzene, 1,3,5-trimethoxybenzene, 1, 2,3-triethoxybenzene, 1,2,4-triethoxybenzene, 1,3,5-triethoxybenzene, 1,2,3,4-tetramethoxybenzene, 1,2,3, 5-tetramethoxybenzene, 1,2,4,5-tetramethoxybenzene, 1-methoxy-2-methylbenzene, 1-methoxy-3-methylbenzene, 1-methoxy-4-methylbenzene, 1-ethyl-2-methoxybenzene, 1-ethyl-3-methoxybenzene, 1-ethyl-4-methoxybenzene, 1-ethoxy-2-methylbenzene, 1-ethoxy-3-methylbenzene, 1-ethoxy-4-methylbenzene, 1-ethoxy-2-ethylbenzene, 1-ethoxy-3-ethylbenzene, 1-ethoxy-4-ethylbenzene, 1-methoxy-2-prop- 2-enylbenzene, 1-methoxy-3-prop-1-enylbenzene, 1-methoxy-3-prop-2-enylbenzene, 1-methoxy-4-prop-2-enylbenzene, 1-methoxy-4-[(E)-prop-1-enyl]benzene (cis), 1-methoxy-4-[(E)-prop-1-enyl]benzene (trans), methyl2 -Ethoxybenzoate, methyl 3-ethoxybenzoate, methyl 4-ethoxybenzoate, ethyl 2-ethoxybenzoate, ethyl 3-ethoxybenzoate, ethyl 4-ethoxybenzoate, ethyl (E) 3-(4-hydroxy-3,5-dimethoxyphenyl)prop-2-enoate, 2-methoxybenzaldehyde, 3-methoxybenzaldehyde, 4-methoxybenzaldehyde, 2- Ethoxybenzaldehyde, 3-ethoxybenzaldehyde, 4-ethoxybenzaldehyde, 2-propoxybenzaldehyde, 3-propoxybenzaldehyde, 4-propoxybenzaldehyde, 2-butoxy Benzaldehyde, 3-butoxybenzaldehyde, 4-butoxybenzaldehyde, 2-methoxybenzonitrile, 3-methoxybenzonitrile, 4-methoxybenzonitrile, 2-methoxybenzoic acid, 3-methoxybenzoic acid, 4-methoxybenzoic acid, 2,3-dimethoxybenzoic acid, 2,4-dimethoxybenzoic acid, 2,5-dimethoxybenzoic acid, 2,6-dimethoxybenzoic acid, 3,4-dimethoxy Benzoic acid, 3,5-dimethoxybenzoic acid, 2,3-dimethoxy-4-methyl benzoic acid, 2,5-dimethoxy-4-methyl benzoic acid, 2,6-dimethoxy-4-methyl benzoic acid, 3,5- Dimethoxy-4-methyl benzoic acid, 2-ethoxybenzoic acid, 3-ethoxybenzoic acid, 4-ethoxybenzoic acid, 2-ethoxy-3-ethyl benzoic acid, 3-ethoxy-5-ethyl benzoic acid, 4-ethoxy -2-ethyl benzoic acid, 4-ethoxy-3-ethyl benzoic acid, 3-ethoxy-4-hydroxybenzoic acid, ethyl 2-methoxybenzoic acid, ethyl 3-methoxybenzoic acid, ethyl 4-methoxybenzoic acid, 2- Hydroxy-3-methoxybenzoic acid, 2-hydroxy-4-methoxybenzoic acid, 2-hydroxy-5-methoxybenzoic acid, 2-hydroxy-6-methoxybenzoic acid, 2-hydroxy-4,5 -Dimethoxybenzoic acid, 2-hydroxy-4,6-dimethoxybenzoic acid, 3-hydroxy-4-methoxybenzoic acid, 3-hydroxy-5-methoxybenzoic acid, 3-hydroxy-4,5-dime Toxybenzoic acid, 4-hydroxy-2-methoxybenzoic acid, 4-hydroxy-3-methoxybenzoic acid, 4-hydroxy-2,6-dimethoxybenzoic acid, 4-hydroxy-3,5-dimethoxybenzoic acid , 3,4-dihydroxybenzoic acid, 3-(4-hydroxy-3,5-dimethoxyphenylprop-2-enoic acid, 2-methoxyphenol, 3-methoxyphenol, 4-methoxyphenol , 2-methoxy-4-(prop-1-enyl)phenol, 2-methoxy-4-prop-2-enylphenol, 4-methoxy-2-[(E)-prop-1- Enyl] phenol, 1-(4-methoxyphenyl)ethanone 2,3-dimethoxyphenol, 2,4-dimethoxyphenol, 2,5-dimethoxyphenol, 2,6-dimethoxyphenol, 3,4 -Dimethoxyphenol, 3,5-dimethoxyphenol, 2,6-dimethoxy-4-prop-2-enylphenol, 2-ethoxyphenol, 3-ethoxyphenol, 4-ethoxyphenol, 4- Ethyl-2,5-dimethoxyphenol, 4-ethyl-2,6-dimethoxyphenol, 2-tert-butyl-4-methoxyphenol, 3-tert-butyl-4-methoxyphenol, 4-tert- Butyl-2-methoxyphenol, 1-(4-hydroxy-2,6-dimethoxyphenyl)ethanone, 1-(4-hydroxy-3,5-dimethoxyphenyl)ethanone, 2-hydroxy -3-methoxybenzaldehyde, 2-hydroxy-4-methoxybenzaldehyde, 2-hydroxy-5-methoxybenzaldehyde, 2-hydroxy-6-methoxybenzaldehyde, 3- Hydroxy-2-methoxybenzaldehyde, 3-hydroxy-4-methoxybenzaldehyde, 3-hydroxy-5-methoxybenzaldehyde, 4-hydroxy-2-methoxybenzaldehyde, 4-hydroxy-3-methoxybenzaldehyde, 2-hydroxy-3,5-dimethoxybenzaldehyde, 2-hydroxy-4,6-dimethoxybenzaldehyde, 4-hydroxy-2, It may be one or more compounds selected from 6-dimethoxybenzaldehyde, 4-hydroxy-3,5-dimethoxybenzaldehyde, and 3-ethoxy-2-hydroxybenzaldehyde.

The second compound may be a monohydric or polyhydric alcohol, and may be one or more compounds selected from linear, branched, cyclic, or mixed forms of alcohols having 1 to 20 carbon atoms. The polyhydric alcohol has two or more alcohol (OH) functional groups.

In addition to selectively dissolving polymers containing urethane functional groups, the first and second compounds can also be directly used as compositions for depolymerization of polymers containing ester functional groups and polymers containing urethane functional groups.

In addition, when the weight ratio of the first compound to the second compound is within a specific range, the selective dissolution efficiency of the polymer containing the urethane functional group is increased. The composition that selectively dissolves the polymer containing the urethane functional group preferably has a weight ratio of the first compound to the second compound (weight of the first compound (g) / weight of the second compound (g)) of 0.01 to 100, A weight ratio of 0.1 to 10 is more preferable, and a weight ratio of 0.5 to 2 is still more preferable.

The composition for selectively dissolving a polymer containing a urethane functional group in the polymer of the mixed material may be a uniform mixture of the first compound and the second compound, but the weight ratio of the first compound/second compound is within the range. As long as satisfies, the first compound and the second compound may exist in a non-uniform, indefinite phase.

In addition, the present invention provides a method of selectively dissolving a polymer containing a urethane functional group from a mixed polymer in which a polymer containing an ester functional group and a polymer containing a urethane functional group are part or all of the components.

The dissolution method includes: a first compound including at least one aromatic compound having one or more alkoxy functional groups in the polymer of the mixed material; and sequentially or simultaneously contacting a second compound containing at least one of the compounds having one or more alcohol functional groups with the polymer of the mixed material to selectively dissolve the polymer containing a urethane functional group in the polymer of the mixed material. It is characterized by ordering.

Since the weight ratio of the first compound and the second compound is the same as that described in the description of the composition above, repeated description is omitted.

The temperature range for selective dissolution of the polymer containing the urethane functional group in the polymer of the mixed material is preferably 100°C to 180°C, more preferably 120°C to 170°C, and even more preferably 140°C to 155°C. .

The first and second compounds may be used in a solid state at room temperature, but are preferably in a liquid state when heated to the above temperature range to selectively dissolve the polymer containing the urethane functional group, and at least one of the constituting compounds It is desirable that it is in a liquid state and can dissolve other compounds.

When sequentially contacting the polymer of the mixed material with the first compound and the second compound, the second compound may be brought into contact with the polymer of the mixed material first, but preferably the first compound is brought into contact with the composite polymer first to remove unnecessary foreign substances. It can be removed. For example, when the first compound is brought into contact with a polymer of a colored mixed material, a series of processes can be configured to first extract and remove pigments and other organic and inorganic foreign substances (dyes, pigments, etc.) contained in the polymer of the colored mixed material. .

At this time, the mass of the first compound compared to the mass of the polymer of the mixed material may range from 0.1 to 1000 times, and the temperature when the first compound and the polymer of the mixed material come into contact may be 100°C to 180°C. If the temperature is less than 100°C, the effect of extracting and removing foreign substances may not be complete, and if it exceeds 180°C, the foreign matter may decompose and contaminate the mixture, or the polymers in the mixed material will depolymerize first, and then urethane functional groups will be formed. Depending on the performance of selective dissolution of polymers containing and individual depolymerization of separated polymers and deterioration of the quality of the final product, the recycling effect for polymers of mixed materials may be insufficient.

The process of removing foreign substances may be performed simultaneously with purging with an inert gas such as nitrogen, or may be performed with purging performed in advance. The contact time is variable depending on the amount of polymer in the mixed material, the temperature at the time of contact, the amount of the first compound, etc., but may range from 1 minute to 24 hours. Additionally, in order to ensure smooth contact, the mixture composed of the first compound and the polymer of the mixed material may be stirred, and the first compound may be added initially or supplied through a continuous flow. In addition, the first compound is recovered from the extract generated in the process of removing foreign substances using separation methods such as distillation, evaporation, and drying, and then re-supplied in the process to remove foreign substances or adjusting the amount of polymer compared to the first compound. It can also be used to

The composition containing the first compound and the polymer of the mixed material previously prepared through the process of removing foreign substances using the first compound is transferred in situ or to a separate process located outside and the second compound is added to contain the urethane functional group. A process can be performed to selectively dissolve the polymer in question. If the foreign matter removal process described above is not performed, the polymer containing the urethane functional group can be selectively dissolved by adding the first mixture and the second mixture together to the polymer of the mixed material. As described above, the composition of each compound must be adjusted so that the weight ratio of the first compound to the second compound (weight of the first compound (g) / weight of the second compound (g)) is 0.01 to 100.

In order to selectively dissolve the polymer containing the urethane functional group from the polymer of the mixed material, the mixture to which the prepared first and second compounds are added can be heated and maintained at a temperature range of 100°C to 180°C. If the temperature is less than 100°C, polyurethane may not dissolve, and if it exceeds 180°C, the polymers in the mixed material may depolymerize first, and it may be difficult to recover high-quality products due to various side reactions.

The process for selectively dissolving the polymer containing the urethane functional group from the polymer of the mixed material may be performed simultaneously with purging with an inert gas such as nitrogen or may be performed with purging performed in advance.

The process for selectively dissolving the polymer containing a urethane functional group from the polymer of the mixed material can be maintained at the temperature for 1 minute to 24 hours, where the first compound and the second compound are added to the mixed material. Stirring may be performed in parallel to ensure smooth contact with the polymer.

After the polymer containing the urethane functional group is selectively dissolved, the polymer containing the undissolved ester functional group and the insoluble polymer in which little chemical or physical change occurs under the dissolution conditions (e.g., cotton, cellulose, polyethylene, polypropylene) , nylon, etc.) can be separated from a mixed solution in which a polymer containing a urethane functional group is dissolved by the first compound and the second compound. The separation method can be performed through means such as filtration, centrifugation, separation after standing, etc., but is not limited as long as it is a means that can separate undissolved polymers from the mixture. The separation method may be carried out in parallel with the process of selectively dissolving the polymer containing the urethane functional group.

Additionally, the present invention provides a depolymerization method for recycling a polymer material that is a mixture of a polymer containing an ester functional group and a polymer containing a urethane functional group. The depolymerization method includes: (a) a first compound containing at least one aromatic compound having one or more alkoxy functional groups in a mixed polymer material of a polymer containing an ester functional group and a polymer containing a urethane functional group; And contacting a second compound containing at least one of a compound having one or more alcohol functional groups to selectively dissolve the polymer containing a urethane functional group in the mixed polymer material; (b) filtering the mixed solution in which the polymer containing the urethane functional group is dissolved after the selective dissolution, and separating the polymer containing the ester functional group and the polymer containing the urethane functional group from the polymer material of the mixed material; and (c) separately depolymerizing the polymer containing the separated ester functional group and the polymer containing the urethane functional group.

In addition, as an embodiment of the present invention, the depolymerization of the polymer containing the urethane functional group in step (c) may be characterized in that the depolymerization is performed by adding a catalyst for depolymerization of the polymer containing the urethane functional group to the filtered filtrate. You can.

The depolymerization catalyst is selected from the group consisting of metal catalysts such as alkaline hydroxide, alkaline earth hydroxide, alkaline acetate, alkaline earth acetate, alkaline carbonate, alkaline bicarbonate, alkaline earth carbonate, and alkali oxide, or guanidine-based or amine-based organic compounds. There may be more than one.

The total mass of the catalyst in the depolymerization composition may be in the range of 0.0001 to 0.5 times the mass of the polymer containing the urethane functional group, preferably in the range of 0.001 to 0.1 times, and the depolymerization temperature is 100°C. It may be carried out in a temperature range of from 170°C to 170°C, preferably from 140°C to 165°C.

When depolymerizing the polymer containing the urethane functional group, the weight of the polymer containing the urethane functional group may correspond to 1 wt% to 200 wt% relative to the total weight of the first compound and the second compound, and the first compound and the second compound The weight ratio, that is, the first compound/second compound weight ratio, may be 0.05 to 20, preferably 0.1 to 10, and more preferably 0.5 to 2.

In step (b), the first compound and/or the second compound is added to the filtrate prepared through filtration after selective dissolution of the polymer containing the urethane functional group, thereby obtaining the first compound and/or the second compound compared to the polymer containing the urethane functional group. Alternatively, the weight ratio of the second compound may be adjusted, but it may be more preferable for the convenience of the process to proceed with the depolymerization reaction without adding the first compound and/or the second compound.

In the present invention, as an example, in step (c), the depolymerization of the polymer containing the ester functional group is carried out by hydrolysis, glycolysis, methanolysis, and ethanolysis. ), Ammonolysis, Aminolysis, etc. may be characterized in that depolymerization is performed through one or more of the depolymerization methods known to date.

At this time, if the polymer containing the ester functional group further contains non-degradable polymers (e.g., cotton, cellulose, polyethylene, polypropylene, nylon, etc.), the polymer containing the ester functional group is added with these substances included. Hardly decomposable polymers that undergo depolymerization and do not undergo decomposition from the depolymerization reaction of the polymer containing the ester functional group can be separated from the reaction product by a relatively simple method such as filtration or centrifugation.

Hereinafter, the pretreatment and depolymerization method for chemical recycling of mixed polymer materials according to an embodiment of the present invention will be described in more detail through examples, comparative examples, and experimental examples.

raw material 1

A mixed material fiber (blended fiber) containing 86% polyester and 14% polyurethane (spandex) by weight, which is colorless because no dye is introduced, was prepared as raw material 1 by cutting it into small squares with a side of about 2 cm.

raw material 2

A colorless, 100% polyester fiber with no dye introduced was prepared as raw material 2 by cutting it into small squares so that each side was about 2 cm.

raw material 3

Spandex yarn, which is colorless because no dye was introduced and is made of 100% polyurethane, was cut into small pieces less than 1 cm in length and prepared as raw material 3.

raw material 4

A square of approximately 2 cm on each side made of mixed fibers containing 86% polyester by weight, 14% polyurethane (spandex), and black dye (dye: Dystar Dianix Deep Black Plus, weight ratio: 2.0% o.w.f.) It was cut into small pieces and prepared as raw material 4.

raw material 5

The fiber is made of a mixed material containing 86% polyester by weight, 14% polyurethane (spandex), and azo-based red dye (dye: Disperse Red 1, weight ratio: 1.5% o.w.f.) into a square of approximately 2cm on each side. It was cut into small pieces and prepared as raw material 5.

raw material 6

Raw material 6 was prepared by adding a mixed material consisting of polypropylene nonwoven fabric, cotton, and nylon to the mixed material fiber of raw material 1, and the weight ratio was 64.5% polyester, 10.5% polyurethane, 10% polypropylene, 10% cotton, And it was made to have a nylon content of 5%. The size of the material was prepared so that the size of one side was 3 cm or less.

Selective dissolution of polyurethane from mixed polymer materials

Example 1

(a) Selective dissolution of polyurethane: Prepare a mixed solvent using 35 g of anisole as the first compound and 60 g of ethylene glycol as the second compound, pour it into a 250 ml container (autoclave) designed to withstand high pressure, and heat it under PID control. The temperature inside the container was maintained at 150°C. When the temperature remained stable, 10 g of fibers of the mixed material prepared as raw material 1 were added, and the mixture was stirred at a speed of 350 rpm or more using an overhead stirrer equipped with a PTFE impeller. When the desired fiber contact time was reached, the mouth of the container was opened, the fibers were taken out using tweezers, washed by immersing them in about 50 ml of an ethanol solution previously prepared in a vial bottle, and then transferred to a glass evaporation dish. Afterwards, it was placed in a vacuum dryer maintained at low pressure (≤ 2 mmHg) by a vacuum pump and a temperature of 60°C by an internal heater, and dried for over 12 hours.

(b) Measurement of the content of polyurethane in the mixed polymer material: Polyurethane was dissolved from the mixed polymer fiber through contact with the mixed solution composed of the first compound and the second compound and discharged as a liquid. The extraction rate of polyurethane according to this was estimated by measuring the content of polyurethane in the fiber sample. For this purpose, 30 mg of the mixed polymer fiber sample was uniformly dissolved in 0.7 ml of a mixed solvent consisting of trifluoroacetic acid-d (TFA- d ) and dichloromethane- d 2 (CD ₂ Cl ₂ ) at a weight ratio of 1:10, and then subjected to nuclear magnetic resonance spectroscopy. ¹ H-NMR spectrum was measured using (nuclear magnetic resonance (NMR), model name: Bruker AVANCE ∥ ⁺ 500 MHz), and the content of polyurethane was estimated from the values of the relative area ratios for the observed characteristic peaks. Prior to this, samples prepared with different mass ratios of raw material 2 (100% polyester) and raw material 3 (100% polyurethane) (mass ratio of polyurethane were 0%, 4%, 8%, 12%, 16%, 20%). ¹ H-NMR spectra were measured for the sample mixed to %, and the characteristic peaks of polyester (δ (ppm) = 8.16, 4.79, 4.63, 4.19, 4.11) and the characteristic peaks of polyurethane (δ A calibration curve was prepared by correlating the relative area ratio for (ppm) = 7.26, 7.19, 3.67, 3.47, 1.78, 1.70, 1.41, 1.30, 0.44, 0.14) as a function of the mass ratio for the constituent polymer.

The rate at which polyurethane is removed from the mixed polymer material by selective dissolution was calculated using the following equation.

_{- PU} extraction _rate :

In the above formula, M _PU,0 is the initial mass of polyurethane in the mixed polymer material, and M _PU is the mass of polyurethane in the mixed polymer material that was in contact with the mixed solution composed of the first compound and the second compound but did not cause selective dissolution.

(c) Separation and recovery of each polymer: According to the process of (a), the mixed solution consisting of the first compound and the second compound is brought into sufficient contact with the polymer material of the mixed material, and the selective dissolution of the polyurethane is completed (b) ), the mixture of fibers and polyurethane in the pressure vessel was filtered using a PTFE membrane filter (pore 0.45μm). Undissolved fibers were obtained on the filter paper, and the filtrate was transferred to a separatory funnel to induce liquid-liquid phase separation. The separated phase was divided into an upper organic solvent layer containing a high concentration of the first compound and a lower hydrophilic solvent layer containing a high concentration of the second compound. Most of the dissolved polyurethane remains mixed with the organic solvent layer in the form of a white, cloudy solution, and the phases are separated. Excessive amounts of n-hexane and water are added to induce clearer phase separation, forming the first and second compounds. was separated and removed. The final separated product was transferred to a 50ml flask, the organic solvent present in the organic phase was removed using a rotary evaporator, and white solid polyurethane was recovered.

(d) Characterization of isolated polymers: Each isolated polymer was structurally analyzed using total reflection infrared spectroscopy (ATR/FT-IR; Bruker ALPHA II) as well as ¹ H-NMR analysis described in the process of (b). Characteristics were observed. As the polyurethane was dissolved through contact with the mixed solution of the first and second compounds, it was observed that the polymer material remaining in the solid phase lost its elasticity, and the shape change of these fabrics was observed under a stereomicroscope (model name: Olympus SZ61). was observed.

Example 2

Each polymer was separated from the mixed polymer material through selective dissolution of polyurethane in the same manner as in Example 1, except that 70 g (double) of anisole was added as the first compound. The characteristics were analyzed.

Comparative Example 1

In preparing the mixed solvent, polyurethane was prepared in the same manner as in Example 1, except that anisole as the first compound and ethylene glycol as the second compound were not used together, and only 70 g of anisole corresponding to the first compound was used. Each polymer was separated from the mixed polymer material through selective dissolution and their properties were analyzed.

Comparative Example 2

In preparing the mixed solvent, polyurethane was prepared in the same manner as in Example 1, except that anisole as the first compound and ethylene glycol as the second compound were not used together, and only 70 g of ethylene glycol corresponding to the second compound was used. Each polymer was separated from the mixed polymer material through selective dissolution and their properties were analyzed.

Table 1 shows the rate at which polyurethane is removed from the mixed polymer through selective dissolution after contacting the mixed polymer raw material consisting of polyester and polyurethane with the first compound and/or the second compound at a temperature of 150°C. It is expressed as a function of . The mixed polymer raw material 1 used here is a blended material in the form of a fabric in which threads composed of polyester and polyurethane are woven by alternating weft (horizontal) and warp (vertical) threads. This can be unraveled and reclassified by material or completely physically separated. It is known that this method is not technically easy to implement. Therefore, the present invention proposes a method of recycling by selectively and completely dissolving one component of the mixed material, converting it into different phases, and then physically separating each of them. A method of selectively dissolving polyurethane can be used, and the solvent used in this case is a mixture of compounds with two different chemical structures as shown in Examples 1 and 2 in Table 1, rather than a single compound. .

Among these, the first compound causes a strong interaction with the hard segment adjacent to the urethane bond, maintaining strong cohesion and thermodynamic stability, and the second compound has high affinity with the soft segment, which forms a flexible polymer chain and has elasticity. Therefore, when these first and second compounds are used together, the effect may be noticeable. As the first compound, an aromatic compound with an alkoxy functional group that has a strong interaction with the hard segment and urethane bond of polyurethane may be selected, and the second compound is expected to have a high thermodynamic affinity with the polyol constituting the soft segment. Solubility can be greatly increased by appropriately composing the alcohol compound. The results in Table 1 explain these effects in detail.

Looking at the results of Comparative Examples 1 and 2, in which only the first compound, anisole, or the second compound, ethylene glycol, was contacted with a polyester-polyurethane mixed material as an extraction solvent, after 2 hours of contact time, the polyurethane Some selective dissolution has occurred, but even if left for a long time, the removal rate of polyurethane is less than 50%, showing that only a very limited amount is dissolved. On the other hand, in Examples 1 and 2, where a mixed solvent containing anisole and ethylene glycol was added simultaneously, selective solvation of polyurethane proceeded rapidly. In particular, in Example 2, where the weight ratio of anisole and ethylene glycol was added similarly, it can be seen that all the polyurethane was dissolved at a rapid rate within 20 minutes of contact time. This clearly shows that the solvent in which the first compound and the second compound are mixed together is very effective in selectively dissolving polyurethane.

Figure 2 shows the shape of the mixed polymer material obtained according to the contact time in Example 1 observed under a stereomicroscope. As the contact time elapsed, polyurethane was selectively dissolved from the mixed polymer material, and as a result, the width of the fabric gradually expanded into a loose fibrous structure. However, as the concentration of polyester increased, the elasticity was observed to be significantly lowered. It has been done.

Figures 3 and 4 show the chemical structures and positions of protons of polyester (raw material 2) and polyurethane (raw material 3), which correspond to the polymers that make up the mixed material of raw material 1.

In order to investigate the structural characteristics of the polymer separated/recovered from the mixed polymer material (raw material 1) by selective dissolution of polyurethane according to the method of Example 1, raw material 2 (polyester) and raw material 3 (polyester) having a single polymer component were separated. urethane) and ¹ H-NMR measurements were performed on the separated polymer samples. The spectra obtained for each are compared in Figure 5. It can be seen that the characteristic peaks of each separated/recovered polymer match well with the characteristic peaks of single polymers (raw material 2 and raw material 3). This well explains that the method of Example 1 was very effective in separating the polymer component through selective dissolution of polyurethane from the polymer material of the mixed material.

Selection of compounds effective in selective dissolution of polyurethane

The following examples and comparative examples show examples of compound combinations effective in selective dissolution of polyurethane.

(1) Modification of the first compound

Example 3

In preparing the mixed solvent, mixing was carried out through selective dissolution of polyurethane in the same manner as in Example 1, except that 1,2-dimethoxy benzene was used instead of anisole as the first compound. Each polymer was separated from the polymer material and its properties were analyzed.

Example 4

In preparing the mixed solvent, mixing was carried out through selective dissolution of polyurethane in the same manner as in Example 1, except that 1,4-dimethoxy benzene was used instead of anisole as the first compound. Each polymer was separated from the polymer material and its properties were analyzed.

Example 5

In preparing the mixed solvent, polyurethane was prepared in the same manner as in Example 1, except that 1,3,5-trimethoxy benzene was used instead of anisole as the first compound. Each polymer was separated from the mixed polymer material through selective dissolution and their properties were analyzed.

Example 6

In preparing the mixed solvent, each polymer was obtained from the polymer material of the mixed material through selective dissolution of polyurethane in the same manner as in Example 1, except that ethoxy benzene was used instead of anisole as the first compound. were separated and their characteristics were analyzed.

Example 7

In preparing the mixed solvent, each polymer was extracted from the polymer material of the mixed material through selective dissolution of polyurethane in the same manner as in Example 1, except that guaiacol was used instead of anisole as the first compound. They were separated and their characteristics were analyzed.

Comparative Example 3

In preparing the mixed solvent, each of the polymer materials of the mixed material was obtained through selective dissolution of polyurethane in the same manner as in Example 1, except that p-xylene (p-xylene) was used instead of anisole as the first compound. Polymers were isolated and their properties were analyzed.

Examples 1, 3 to 7 and Comparative Example 3 compare the effects on selective dissolution of polyurethane when the type of the first compound is changed in separating each polymer from a mixed polymer material. In all experimental examples, only the type of the first compound was changed for performance comparison, and other conditions were applied the same. In examples in which an aromatic compound having at least one alkoxide functional group was used, it was found that dissolution of polyurethane proceeded very selectively and efficiently. In particular, 1,2-DMB, which has substituted alkoxy functional groups on the aromatic ring adjacent to each other, showed very effective polyurethane dissolution performance. This means that when multiple alkoxy functional groups are arranged in the same direction, the aromatic structure located at the center of the hard segment in the polyurethane structure and the urethane bonding groups symmetrically located on both left and right sides have a strong interaction with the alkoxy functional groups of 1,2-DMB. It can be estimated as a result.

Meanwhile, Comparative Example 3 examines the effect of para-xylene, an aromatic hydrocarbon compound, as a first compound in order to selectively dissolve polyurethane from a mixed material. Paraxylene is relatively stable with a boiling point of about 138°C and has low polarity, but is one of the good solvents that is often used as a solvent for dissolving various polymers along with toluene. It has an aromatic ring at the center and a methyl group on the outside of the substituent, so it has a structural similar form to 1,4-dimethoxybenzene used as the first compound in Example 4, but the functional group directly substituted on the aromatic ring is methyl. It is a compound that has a methyl group rather than a toxi group. From the results of Example 4 in which 1,4-dimethoxybenzene was used, most of the polyurethane was dissolved when the contact time with the mixed polymer material was maintained for 2 hours at a temperature of 150°C, but paraxylene was used as the first compound. In Comparative Example 3, the proportion of polyurethane dissolved in the mixed solvent was observed to be less than half. This well explains that applying a simple combination of solvents that have or are expected to have high affinity for the polymer is not necessarily effective in selectively dissolving polyurethane from the mixed material.

(2) Modification of the second compound

Example 8

In preparing the mixed solvent, each was obtained from the polymer material of the mixed material through selective dissolution of polyurethane in the same manner as in Example 1, except that diethylene glycol (DEG) was used instead of ethylene glycol as the second compound. The polymers were separated and their properties were analyzed.

Example 9

In preparing the mixed solvent, each was obtained from the polymer material of the mixed material through selective dissolution of polyurethane in the same manner as in Example 1, except that triethylene glycol (TEG) was used instead of ethylene glycol as the second compound. The polymers were separated and their properties were analyzed.

Example 10

In preparing the mixed solvent, each polymer material of the mixed material was obtained through selective dissolution of polyurethane in the same manner as in Example 1, except that 1-octanol (1-octanol) was used instead of ethylene glycol as the second compound. The polymers were separated and their properties were analyzed.

Comparative Example 4

In preparing the mixed solvent, each of the polymer materials of the mixed material was obtained through selective dissolution of polyurethane in the same manner as in Example 1, except that n-decane was used instead of ethylene glycol as the second compound. Polymers were isolated and their properties were analyzed.

Table 3 shows a comparison of the effect on selective dissolution of polyurethane when changing the type of the second compound in separating each polymer from the mixed polymer material. In all experimental examples in Table 3 (Examples 1, 8 to 10, and Comparative Example 4), only the type of the first compound was changed for performance comparison, and other conditions were applied the same. As can be seen from the results of Examples 1, 8 to 10, when a compound having at least one alcohol functional group (second compound) is used in combination with an aromatic compound having an alkoxy functional group (first compound), a very effective and selective poly It can be seen that the dissolution of urethane is progressing. Not only was ethylene glycol, in which an alcohol functional group is bonded to the end of the hydrocarbon chain structure, applied as the second compound (Example 1), but also multiple diols such as diethylene glycol or triethylene glycol were bonded together to form a larger molecular structure. Even when diol was applied as the second compound (Examples 8 and 9), the performance for selective dissolution of polyurethane was similar. In particular, in Example 10, in which 1-octanol, which has a long hydrocarbon chain structure but only one alcohol functional group at the terminal, was used as the second compound, very effective dissolution of polyurethane proceeded.

Meanwhile, as another example of the second compound, when decane, which has a chain length similar to 1-octanol (Example 10) but consists only of hydrocarbons instead of an alcohol functional group, is used, it can be seen that the dissolution of polyurethane hardly progresses. . From this, it can be seen that in order to increase the selective dissolution performance of polyurethane from mixed polymer materials, not only the selection of the first compound but also the appropriate selection of the second compound is very important.

Figure 6 shows a comparison of some representative IR spectra measured for the polyester and polyurethane isolated from the above examples and samples of raw material 2 and raw material 3 as starting materials. In order to compare the structure and component properties of the polymers separated according to the methods of the Examples, not only the polyester and polyurethane separated according to the methods of the Examples, but also the raw materials 2 and 3 corresponding to a single polymer were used. The spectra are also shown. The polymers separated by the methods of the examples showed a form very similar to the spectrum of single polymers. This is a method of selectively dissolving polyurethane and separating the composition of the polymer through this according to the present invention, that is, when the mixed polymer material is contacted with a solvent mixed by the first compound and the second compound for a certain period of time in a heated state, polyurethane It is well explained that the selective dissolution of proceeds and that the polymer components that make up the mixed material can be separated very effectively. Because the selective dissolution of polyurethane proceeds quickly through simple contact, the individual polymers (polyester and polyurethane) that make up the mixed material can be completely separated from each other by a relatively simple and efficient method.

Effect of extraction temperature on selective dissolution of polyurethane

The following examples and comparative examples show the effects of extraction temperature on the selective dissolution of polyurethane.

Comparative Example 5

In the same manner as in Example 2, except that the temperature inside the container was maintained at 90°C and stirred for 24 hours, each polymer was separated from the polymer material of the mixed material through selective dissolution of polyurethane and their properties were analyzed. analyzed.

Example 11

In the same manner as in Example 2, except that the temperature inside the container was maintained at 100°C and stirred for 24 hours, each polymer was separated from the polymer material of the mixed material through selective dissolution of polyurethane and their properties were analyzed. analyzed.

Comparative Example 6

In the same manner as in Example 2, except that the temperature inside the container was maintained at 190°C and stirred for 1 hour, each polymer was separated from the polymer material of the mixed material through selective dissolution of polyurethane and their properties were analyzed. analyzed.

Table 4 shows the dissolution rate of polyurethane according to contact temperature when separating each polymer by selective dissolution of polyurethane from the mixed polymer material. When left for more than 24 hours while maintaining the contact temperature at 100°C (Example 11), slow but gradual dissolution of polyurethane was observed to occur. However, as in Comparative Example 5, it was observed that the dissolution rate dropped sharply at a contact temperature of 90°C, which was lowered by 10°C.

Meanwhile, in the case of Comparative Example 6, in which the mixed solvent consisting of the first compound and the second compound was maintained at a high temperature (190°C) and brought into contact with the polymer material of the mixed material, the deterioration and oxidation of polyurethane were greatly accelerated, resulting in excessive A color change (yellowing) was observed, and decomposition of polyester progressed. After exposure to high temperature for about 1 hour, a portion of the liquid product (filtrate) was taken and measured by HPLC, and it was found that the polyester itself was partially depolymerized. The yield of oligomers (including dimers) generated from the depolymerization of polyester was observed to be about 4.1%.

Foreign matter removal effect due to sequential application of the first and second compounds

The following examples and comparative examples are intended to determine the effect of removing foreign substances on mixed polymer materials containing organic impurities other than polymers.

Comparative Example 7

Approximately 10 g of mixed fiber mixed with black dye prepared as raw material 4 was placed in a 250 ml flask containing 70 g of anisole (first compound) previously heated to 90°C and stirred at 300 rpm for approximately 5 minutes using a magnetic stirrer. The dye was extracted. After removing the mixed solution colored by the eluted dye, it was transferred to 70 g of anisole maintained at the same temperature and washed. Washing was repeated up to three times until the dye no longer eluted from the anisole used for washing.

The decolorized mixed material fiber was measured using a spectrophotometer (manufacturer: Konica Minolta, model name: CM-3600A) and obtained as L* a* b* values. The values expressed as L* a* b* are coordinate values of the color space standardized by the International Commission on Illumination (CIE), and L* is expressed as 0 (black) to 100 (white) representing lightness. It is a numerical value, and a* and b* are numerical values expressed as positive/negative coordinate values expressed along the complementary color axes of red/green and yellow/blue, respectively. Additionally, the change in dyeing amount can be estimated from the K/S value using the Kubelka-Munk equation expressed as the following equation.

- K/S = (1 - R) ² / (2×R) (Formula 2)

Here, K is the absorption coeff. of the dye, S is the scattering coeff. of the dye, and R represents the spectral reflectance (reflectance of monochromatic light). The K/S value, which means the apparent amount of dyeing, can be calculated from the reflectance of the dyed material measured at the maximum absorption wavelength of the dye.

The solution containing approximately 70 g of mixed material fiber and anisole, which is finally obtained through the washing process, is placed in a 200 ml pressure vessel (autoclave) in which 35 g of ethylene glycol, corresponding to the second compound, is pre-added and maintained at 150°C. Afterwards, each polymer was separated from the mixed material through selective dissolution of polyurethane in the same manner as in Example 1, and their properties were analyzed.

Example 12

In removing dye foreign substances from the fiber of the colored mixed material of raw material 4, dye foreign substances were removed in the same manner as in Comparative Example 7, except that the temperature of anisole used as the first compound was maintained at 110 ° C., and the polyurethane Each polymer was separated from the mixed polymer material through selective dissolution and their properties were analyzed.

Example 13

In removing dye foreign substances from the fiber of the colored mixed material of raw material 4, dye foreign substances were removed in the same manner as in Comparative Example 7, except that the temperature of anisole used as the first compound was maintained at 130 ° C., and the polyurethane Each polymer was separated from the mixed polymer material through selective dissolution and their properties were analyzed.

Example 14

In removing dye foreign substances from the fiber of the colored mixed material of raw material 4, dye foreign substances were removed in the same manner as in Comparative Example 7, except that the temperature of anisole used as the first compound was maintained at 150 ° C., and the polyurethane Each polymer was separated from the mixed polymer material through selective dissolution and their properties were analyzed.

Example 15

In the same manner as Comparative Example 7, except that raw material 5 with red dye introduced instead of raw material 4 was used as a colored mixed material fiber, and the temperature of anisole used as the first compound in removing dye foreign substances was maintained at 150°C. Dye foreign substances were removed, and each polymer was separated from the mixed polymer material through selective dissolution of polyurethane and their characteristics were analyzed.

Comparative Example 8

In the same manner as Comparative Example 7, except that raw material 5 with red dye introduced instead of raw material 4 was used as a colored mixed material fiber, and the temperature of anisole used as the first compound in removing dye foreign substances was maintained at 190°C. Dye foreign substances were removed, and each polymer was separated from the mixed polymer material through selective dissolution of polyurethane and their characteristics were analyzed.

Table 5 shows the color characteristics of fibers that were decolorized through contact with the first compound. Each decolorized fiber is photographed in Figure 7. In the case of Comparative Example 7, which corresponds to a contact temperature with the first compound (anisole) of less than 100°C, partial decolorization occurred, but the K/S value was above 15, so the residual amount of dye was observed to be relatively high. The second compound was added to the mixed polymer material to which the first compound was added to selectively dissolve the polyurethane. When filtration was performed to separate it from the polyester, very dark-colored foreign substances remained in the filtrate, which was then removed from the polyurethane. It also had a significant impact on the quality of the product obtained by performing depolymerization.

On the other hand, when decolorizing is carried out through contact with the first compound, if the contact temperature is maintained at a temperature of 100 ℃ or higher, dedying is effectively carried out, and the second compound is added to selectively dissolve the polyurethane, thereby producing high purity polyurethane. The polymer could be obtained as a raw material for depolymerization. Meanwhile, in the case of Comparative Example 8 in which decolorization was carried out at too high a temperature, the mixed solvent consisting of the first compound and the second compound was maintained at a high temperature of 190°C and contacted with the polymer material of the mixed material. As in the case of , deterioration and oxidation of polyurethane were greatly accelerated, and excessive color change (yellowing) was observed.

Depolymerization reaction of mixed materials or polymers separated from them

Example 16

(a) Depolymerization reaction of polyester: In separating the mixed material according to the method of Example 2, the polyurethane dissolved by the filtration process in (c) is removed as a filtrate and the remaining fibers on the filter paper are dried. The total mass of about 10 g on a dry basis and anisole is 22.5 g (ratio of 4 moles per mole of terephthalate monomer in the polymer), and ethylene glycol is about 38.8 g (ratio of 12 mole per mole of terephthalate monomer in the polymer). After each addition was added to a 3-neck flask, a reflux condenser was installed at atmospheric pressure, and stirring was started using a magnetic stirrer. When the reaction mixture reached the reflux temperature (153°C) of the first compound, about 0.20 g of potassium acetate catalyst was added to initiate the catalytic reaction. Stirring was continued for 2 hours, but the reaction temperature was kept constant within ±1°C. The reaction was carried out using a condenser with one end exposed to atmospheric pressure. At the end of the reaction, a trace amount of the reaction mixture was taken and prepared as a sample for quantification. The reaction yields for depolymerized monomers and dimers were measured using high-performance liquid chromatography (HPLC with C ₁₈ column, UV detector (λ=254nm)) calibrated with each standard sample.

(b) Analysis of depolymerization product: A mixed solution of methanol:water with a volume ratio of 70:30 was used as the mobile phase for HPLC analysis, and the total flow rate was maintained at 0.7 ml/min. All reaction mixtures, except for trace samples taken for quantification, were filtered using cellulose filter paper (pore size: 3 μm). Solid compounds other than monomers, such as dimers, oligomers, and unreacted polymers, were obtained as solid content on the filter paper. The yield of the products in the reactants was calculated using the following equation.

- Yield of monomer, Y _BHET (%) = M _BHET /M ₀ × 100 (Formula 3)

- Yield of dimer, Y _Dimer (%) = M _Dimer /M ₀ × 100 (Formula 4)

- Yield of oligomer, Y _Oligomer (%) = M _Oligomer /M ₀ × 100 (Formula 5)

- Yield of by-product (MHET), Y _MHET (%) = M _MHET /M ₀ × 100 (Equation 6)

Here, M _BHET , M _Dimer , M _Oligomer , and M _MHET represent the number of moles of terephthalate functional groups possessed by BHET, dimer, oligomer, and MHET, respectively, as quantified by HPLC, and M ₀ represents the number of moles of repeating units in the input polymer structure. .

(c) Recovery of depolymerization product: After adding 100 ml of distilled water to the depolymerization product, the reaction mixture solution containing the monomers was left in a storage room maintained at a temperature of 4°C for 12 hours, and the crystallized solid phase was transferred to a cellulose filter paper (pore size: 3μm) was used to remove a large amount of moisture and then taken as solid content. The obtained solid content was again transferred to a vacuum dryer maintained at a temperature of 60°C and vacuum dried for more than 12 hours to obtain a monomer product.

In Example 16, a catalyst and a reaction solvent were further added to the polyester separated according to the method of Example 2, and then a depolymerization reaction (glycolysis) was performed. In the depolymerization reaction of the separated polyester, the product distribution of the depolymerization product obtained after 2 hours of reaction time is shown in Table 6. Dominant decomposition of polyester fibers occurred until the reaction time was 30 minutes, and when the reaction time was 2 hours, complete depolymerization occurred and unreacted polyester was not detected. It is known that the product yield after the glycolysis reaction of polyester is determined by the reaction equilibrium between the monomer BHET and the oligomer including the dimer. The yield values (Table 6) of the products obtained from the depolymerization reaction of polyester isolated from the mixed polymer material (Example 16) are similar to those obtained from the glycolysis reaction of a single component (relatively clean PET flake or polyester). was observed very similarly to

As a result of analyzing the purity of the solid product obtained through the purification and recovery process of the depolymerization product in (c) in Example 16 by HPLC, it was found that a high-purity BHET product with a purity of 99.2% was finally obtained.

Example 17

(a) Depolymerization reaction of polyurethane: When separating mixed materials according to the method of Example 2, about 131 g of the mixture containing polyurethane separated into the filtrate through the filtration process in (c) was placed in a PID temperature controller. It was placed in a thermostat filled with high-temperature methyl phenyl silicone oil that can be maintained at a constant temperature, and the mixture was stirred at a speed of 250 rpm until the temperature inside the reactor reached 150°C. When the temperature inside the reactor was stabilized, 0.2 g of sodium hydroxide (KOH) was added as a catalyst to start the reaction. Polyurethane of raw material 3, polytetrahydrofuran (PTFA), which has the same structure as the polyol used for polyurethane synthesis, manufacturer: Sigma-Aldrich, number average molecular weight (Mn): ~2,000), depolymerization During the process, total reflection infrared spectroscopy (ATR/FT-IR; Bruker ALPHA II) was performed on the regenerated polyol obtained by taking a portion of the reaction product, and the spectra obtained therefrom were compared and observed to determine whether depolymerization was complete.

(b) Recovery of reaction solvent

After the reaction was carried out by maintaining the temperature inside the reactor at 150°C for 2 hours, the reactor was separated from the oil thermostat to terminate the reaction. When the temperature was lowered below 100°C and the boundary region between the phases was clearly observed, unreacted ethylene glycol and a number of catalysts in the lower phase were recovered using a separatory funnel. The organic compounds separated into the upper phases were transferred to a 100 ml evaporation flask with a known empty vessel weight and then quantified.

(c) Obtaining polyol products

A 100 ml evaporating flask containing the previously separated phase mixture is connected to a rotary evaporator and rotated at a speed of 150 rpm while continuously in contact with a constant temperature water bath maintained at 65°C. The distillate is evaporated for about 1 hour under reduced pressure conditions (10 torr). was completely removed. Approximately 1 g of the pale yellow, highly viscous liquid remaining in the rotary evaporator was taken as a polyol product.

(d) Characterization of polyol products

In order to analyze the bonding structure of the functional groups of the recycled polyol finally prepared according to the depolymerization and solvent separation process, a portion was taken as an ATR sample and FT-IR analysis was performed.

Meanwhile, the structural properties of the polyol polymer (PTFA) used in polyurethane synthesis and the regenerated polyol prepared from depolymerization could be compared using ¹ H-NMR. ¹ H-NMR sample was prepared by uniformly dissolving 30 mg in 0.7 ml of a mixed solvent consisting of trifluoroacetic acid- d (TFA- d ) and dichloromethane- d ₂ (CD ₂ Cl ₂ ) at a weight ratio of 1:10.

Example 18

Each polymer was separated from the mixed polymer material through selective dissolution of polyurethane in the same manner as in Example 2, except that 15 g of raw material 6 was used instead of raw material 1 as a colored mixed polymer material, and their properties were analyzed. did. In separating the mixed material according to the method of Example 2, the polymer material (about 11.3 g based on dried mass) remaining on the filter paper in the filtration process of (c) was used to perform a depolymerization reaction according to the same method as Example 16. By performing this, a depolymerization product containing glycolysis monomer (BHET) was obtained.

During the filtration process after the reaction, not only solid compounds other than monomers such as dimers, oligomers, and unreacted polymers, but also polypropylene, cotton, and nylon were recovered on the filter paper. The recovered shape was similar to the original shape of raw material 6, and about 3.7g, which was an approximate mass compared to the amount input, was recovered.

Example 19

In Example 18, when separating mixed materials according to the method of Example 2, potassium hydroxide (KOH) was added to the liquid mixture (about 131 g) containing the polyurethane separated as the filtrate in the filtration process of (c). Depolymerization reaction and analysis were performed in the same manner as in Example 17, except that 0.2 g of potassium carbonate (K ₂ CO ₃ ) was added as a catalyst to start the reaction. After removing the first and second compounds from the depolymerization product of dissolved polyurethane, approximately 1.1 g of a light yellow recycled polyol product was obtained.

Figure 8 shows the structure of the polyol expected to be obtained when the polyurethane separated from the mixed polymer material of raw material 1 is depolymerized and the location of the proton. This also shows the general chemical structure of polytetrahydrofuran, a spandex raw material mainly used in blended fibers manufactured to have high elasticity among polyurethanes.

Figure 9 compares ¹ H-NMR spectra for polyols (Examples 17 and 19) obtained by depolymerizing polyurethane separated from mixed polymer materials and PTFA reagent with a number average molecular weight of about 2,000. Spectra very similar to each other were observed, which means that the polyol product obtained by separating polyurethane from the mixed polymer material and depolymerizing it has the same chemical structure as PTFA, the raw material used to synthesize polyurethane.

Figure 10 compares IR spectra obtained through ATR analysis after taking as a sample some of the polyol products (Examples 17 and 19) obtained through depolymerization and PTFA supplied from the manufacturer. The polyol product obtained by depolymerizing polyurethane had characteristic peaks very similar to PTFA. Meanwhile, in products obtained from depolymerization of polyurethane, characteristic peaks for amine functional groups were observed as weak signals. This may be a characteristic peak representing a urethane linkage group that can be detected when a trace amount of amine impurity in the product has entered the depolymerization product or the decomposition of the polyurethane has not progressed completely and some semi-finished products in the form of oligomers remain in the product. These trace impurities are removed during the synthesis of polyurethane, or even if they remain, they do not significantly affect the polymerization performance when resynthesizing the material.

The present invention has been described above with reference to the embodiments shown in the accompanying drawings, but these are merely illustrative, and various modifications and other equivalent embodiments can be made by those skilled in the art. You will understand that Therefore, the scope of technical protection of the present invention should be determined by the claims below.

Claims (12)

At least one first compound selected from aromatic compounds having at least one alkoxy functional group; and at least one second compound selected from compounds having at least one alcohol functional group.
A composition for selectively dissolving and separating a polymer containing a urethane functional group from a mixed polymer containing both a polymer containing an ester functional group and a polymer containing a urethane functional group.
According to paragraph 1,
Characterized in that the weight ratio of the first compound / second compound is 0.01 to 100,
A composition for selectively dissolving and separating a polymer containing a urethane functional group from a mixed polymer containing both a polymer containing an ester functional group and a polymer containing a urethane functional group.
According to paragraph 1,
The polymer of the mixed material further includes one or more polymers selected from cotton, cellulose, polyethylene, polypropylene, and nylon,
A composition for selectively dissolving and separating a polymer containing a urethane functional group from a mixed polymer containing both a polymer containing an ester functional group and a polymer containing a urethane functional group.
In a method of separating a polymer containing a urethane functional group and a polymer containing an ester functional group from a mixed polymer containing both a polymer containing an ester functional group and a polymer containing a urethane functional group,
A first compound containing at least one aromatic compound having one or more alkoxy functional groups and a second compound containing at least one compound having one or more alcohol functional groups are sequentially added to the polymer of the mixed material. Characterized in that the polymer containing the urethane functional group is selectively dissolved and separated from the polymer of the mixed material by contacting or simultaneously contacting with,
A method of separating a polymer containing a urethane functional group and a polymer containing an ester functional group from a mixed polymer containing both a polymer containing an ester functional group and a polymer containing a urethane functional group.
According to paragraph 4,
Characterized in that the temperature range for selective dissolution of the polymer containing a urethane functional group is 100 to 180 ° C.
A method of separating a polymer containing a urethane functional group and a polymer containing an ester functional group from a mixed polymer containing both a polymer containing an ester functional group and a polymer containing a urethane functional group.
According to paragraph 4,
Sequential contact is characterized in that the first compound is contacted first, followed by the second compound,
A method of separating a polymer containing a urethane functional group and a polymer containing an ester functional group from a mixed polymer containing both a polymer containing an ester functional group and a polymer containing a urethane functional group.
According to paragraph 4,
The mass of the first compound relative to the polymer mass of the mixed material is in the range of 0.1 to 1000 times, and the weight ratio of the first compound / second compound is 0.01 to 100,
A method of separating a polymer containing a urethane functional group and a polymer containing an ester functional group from a mixed polymer containing both a polymer containing an ester functional group and a polymer containing a urethane functional group.
(a) a mixed polymer containing both a polymer containing an ester functional group and a polymer containing a urethane functional group, a first compound containing at least one aromatic compound having one or more alkoxy functional groups, and one or more alcohol functional groups. sequentially or simultaneously contacting a second compound containing at least one of the compounds to selectively dissolve the polymer containing a urethane functional group in the polymer of the mixed material;
(b) filtering the mixed solvent of the first compound and the second compound in which the polymer containing the urethane functional group was dissolved after the selective dissolution, to obtain a polymer containing an ester functional group and a polymer containing a urethane functional group from the polymer of the mixed material. separating; and
(c) separately depolymerizing the polymer containing the separated ester functional group and the polymer containing the urethane functional group;
A polymer regeneration method of a mixed material containing both a polymer containing an ester functional group and a polymer containing a urethane functional group.
According to clause 8,
The depolymerization of the polymer containing the urethane functional group in step (c) is characterized in that the depolymerization is carried out by adding a catalyst for depolymerization of the polymer containing the urethane functional group to the filtered filtrate in step (b).
A polymer regeneration method of a mixed material containing both a polymer containing an ester functional group and a polymer containing a urethane functional group.
According to clause 9,
Catalysts for polymer depolymerization containing a urethane functional group include metal catalysts of alkaline hydroxide, alkaline earth hydroxide, alkaline acetate, alkaline earth acetate, alkaline carbonate, alkaline bicarbonate, alkaline earth carbonate, and alkaline oxide; And at least one selected from the group consisting of guanidine-based or amine-based organic compounds,
A polymer regeneration method of a mixed material containing both a polymer containing an ester functional group and a polymer containing a urethane functional group.
According to clause 9,
The depolymerization of the polymer containing the urethane functional group is characterized in that it is carried out at a temperature range of 100 to 170 ° C.
A polymer regeneration method of a mixed material containing both a polymer containing an ester functional group and a polymer containing a urethane functional group.
According to clause 9,
In step (c), the depolymerization of the polymer containing the ester functional group is carried out by hydrolysis, glycolysis, methanolysis, ethanollysis, and ammonolysis. Characterized in that depolymerization is performed using one or more of the following methods:
A polymer regeneration method of a mixed material containing both a polymer containing an ester functional group and a polymer containing a urethane functional group.