Recycled cyclic carbonate composition and method for producing same

Abstract

The present invention comprises an alkylene carbonate, 1 The present invention relates to a recycled cyclic carbonate composition, which is characterized in that it further contains a phenolic compound having a mass ratio of 5 mass% or less, based on the total mass of the composition, as measured by H NMR, and is recovered from a polycarbonate resin, and a method for producing the same.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0155347, filed November 18, 2022, Korean Patent Application No. 10-2023-0052249, filed April 20, 2023, Korean Patent Application No. 10-2023-0159224, filed November 16, 2023, and Korean Patent Application No. 10-2023-0159225, filed November 16, 2023, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to a recycled cyclic carbonate composition recovered by recycling polycarbonate resins through chemical decomposition, and a method for producing the same. [Background technology]

[0003] Polycarbonate is a thermoplastic polymer that has excellent properties such as excellent transparency, ductility, and relatively low manufacturing costs.

[0004] Although polycarbonate is widely used for a variety of purposes, environmental and health concerns have been raised regarding its waste disposal.

[0005] Currently, physical recycling methods are being used, but this has led to problems such as a deterioration in quality, and research is underway into chemical recycling of polycarbonate.

[0006] Chemical decomposition of polycarbonate refers to the decomposition of polycarbonate to obtain aromatic diol compounds (e.g., bisphenol A (BPA)) and carbonate compounds (e.g., diethyl carbonate), which are monomers that constitute polycarbonate.

[0007] Typical examples of such chemical decomposition include pyrolysis, hydrolysis, and alcoholysis. Among these, alcoholysis is the most common method. However, methanolysis has the drawback of using methanol, which is harmful to the human body, and ethanol requires high temperature and pressure conditions, resulting in a low yield.

[0008] On the other hand, cyclic carbonates such as ethylene carbonate are useful as solvents for high molecular weight polymers and synthetic fuels for carbonate esters, and can also be used as liquid electrolyte organic solvents for electric vehicle batteries. Conventional ethylene carbonate has been produced by industrial synthesis using ethylene oxide and carbon dioxide, but there is a demand for the development of more environmentally friendly methods.

[0009] For this reason, as mentioned above, there is a growing need to develop a method for producing industrially useful cyclic carbonates by chemically decomposing polycarbonates, taking advantage of the fact that carbonate compounds can be obtained by chemically decomposing polycarbonates. Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention provides a recycled cyclic carbonate composition that can ensure high purity of a cyclic carbonate compound recovered by recycling polycarbonate resins through chemical decomposition, and a method for producing the same. [Means for solving the problem]

[0011] In order to solve the above problems, the present specification provides a polymerizable composition containing an alkylene carbonate, 1 The recycled cyclic carbonate composition further contains a phenolic compound in an amount of 5 mass% or less, based on the total mass of the composition, as measured by H NMR, and is recovered from a polycarbonate resin.

[0012] The present specification also provides a method for producing a recycled cyclic carbonate composition, including the steps of: adding a polycarbonate resin to an organic solvent to prepare a mixed solution; adding an alkylene glycol and an inorganic base catalyst to the mixed solution to depolymerize the polycarbonate resin; removing an aromatic diol compound, an organic solvent, and an alkylene glycol from the depolymerized solution; and recovering an alkylene carbonate from the depolymerized solution from which the aromatic diol compound, the organic solvent, and the alkylene glycol have been removed.

[0013] The recycled cyclic carbonate composition and its production method according to specific embodiments of the invention are described in more detail below.

[0014] Unless expressly stated otherwise herein, terminology is for the purpose of referring to particular embodiments only and is not intended to be limiting of the invention.

[0015] As used herein, the singular forms "a," "an," and "the" include the plural forms as well, unless the context clearly dictates to the contrary.

[0016] As used herein, the meaning of "comprising" embodies certain properties, regions, integers, steps, operations, elements, and / or components, and does not exclude the presence or addition of other certain properties, regions, integers, steps, operations, elements, components, and / or groups.

[0017] In this specification, terms including ordinal numbers such as "first" and "second" are used to distinguish one component from another, and are not limited by the ordinal numbers. For example, within the scope of the present invention, a first component may be called a second component, and similarly, a second component may be called a first component.

[0018] As used herein, the term "substituted or unsubstituted" refers to a group substituted or unsubstituted with one or more substituents selected from the group consisting of deuterium, halogen, cyano, nitro, hydroxy, carbonyl, ester, imide, amide, primary amino, carboxy, sulfonic acid, sulfonamide, phosphine oxide, alkoxy, aryloxy, alkylthioxy, arylthioxy, alkylsulfoxy, arylsulfoxy, silyl, boron, alkyl, cycloalkyl, alkenyl, aryl, aralkyl, aralkenyl, alkylaryl, alkoxysilylalkyl, arylphosphine, or a heterocyclic group containing one or more N, O, and S atoms, and refers to a group in which two or more of the above-listed substituents are linked together. For example, a "substituent linked to two or more substituents" may be a biphenyl group. In other words, a biphenyl group may be an aryl group or may be interpreted as a substituent in which two phenyl groups are linked together.

[0019] In this specification, an alkyl group is a monovalent functional group derived from an alkane, and may be linear or branched, and the number of carbon atoms in the linear alkyl group is not particularly limited, but is preferably 1 to 20. Furthermore, the number of carbon atoms in the branched alkyl group is 3 to 20. Exemplary alkyl groups include, but are not limited to, methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methylbutyl, 1-ethylbutyl, pentyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, heptyl, n-heptyl, 1-methylhexyl, octyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 1-ethylpropyl, 1,1-dimethylpropyl, isohexyl, 2-methylpentyl, 4-methylhexyl, 5-methylhexyl, 2,6-dimethylheptan-4-yl, and the like. The alkyl group may be substituted or unsubstituted, and when substituted, examples of the substituent are as described above.

[0020] In this specification, an alkylene group is a divalent functional group derived from an alkane, and the above description of the alkyl group is applicable, except that it is a divalent functional group. For example, it may be linear or branched, and may be a methylene group, ethylene group, propylene group, isobutylene group, sec-butylene group, tert-butylene group, pentylene group, hexylene group, etc. The alkylene group may be substituted or unsubstituted, and if substituted, examples of the substituent are as described above.

[0021] Throughout this specification, "one or more" means, for example, "1, 2, 3, 4 or 5, particularly 1, 2, 3 or 4, more particularly 1, 2 or 3, even more particularly 1 or 2."

[0022] 1. Recycled cyclic carbonate composition According to one embodiment of the invention, the composition comprises an alkylene carbonate, 1 A recycled cyclic carbonate composition can be provided, which further contains a phenolic compound in an amount of 5 mass% or less, based on the total mass of the composition, as measured by H NMR, and which is recovered from a polycarbonate resin.

[0023] The inventors have confirmed through experiments that the recycled cyclic carbonate composition of one embodiment, although recovered through the chemical decomposition of polycarbonate resin, has high purity comparable to that of newly synthesized alkylene carbonates and significantly reduced impurities, and therefore can achieve excellent physical properties when used in a variety of applications (e.g., solvents for polymers, synthetic fuels for carbonate esters, liquid electrolyte organic solvents for electric vehicle batteries, etc.), thereby completing the invention.

[0024] In other words, the present invention has the technical advantage of being able to obtain a highly pure composition containing alkylene carbonate by recycling polycarbonate resin through chemical decomposition.

[0025] Specifically, the recycled cyclic carbonate composition of the embodiment is characterized by being recovered from a polycarbonate-based resin, meaning that, as a result of proceeding with recovery from a polycarbonate-based resin to obtain the recycled cyclic carbonate composition of the embodiment, a recycled cyclic carbonate composition containing alkylene carbonate is also obtained.

[0026] The term "polycarbonate-based resin" refers to any homopolymer or copolymer containing a polycarbonate repeating unit, collectively referring to a reaction product obtained by the polymerization or copolymerization of monomers containing an alkylene carbonate and a carbonate precursor. A homopolymer is synthesized when a single carbonate repeating unit is obtained using only one alkylene carbonate and one carbonate precursor. A copolymer is synthesized when two or more carbonates are contained using one alkylene carbonate and two or more carbonate precursors, two or more alkylene carbonates and one carbonate precursor, or one alkylene carbonate, one carbonate precursor, and one or more other diols. The homopolymer or copolymer may include low molecular weight compounds, oligomers, and polymers within a range of molecular weights.

[0027] The recycled cyclic carbonate composition of the embodiment may contain an alkylene carbonate, such as ethylene carbonate, propylene carbonate, or a mixture thereof.

[0028] The alkylene carbonate is recovered from the polycarbonate resin used to recover the recycled cyclic carbonate composition. In other words, the alkylene carbonate is also obtained as a result of recovery from the polycarbonate resin to obtain the recycled cyclic carbonate composition of the embodiment. Therefore, when new alkylene carbonate is added from outside, separately from the recovery from the polycarbonate resin, to produce the recycled cyclic carbonate composition of the embodiment, it is not included in the scope of the alkylene carbonate of the present invention.

[0029] Specifically, the term "recovered from a polycarbonate-based resin" means that the polycarbonate-based resin is obtained by depolymerization of the polycarbonate-based resin. The depolymerization may be carried out under acidic, neutral, or basic conditions, and is particularly allowed to proceed under basic (alkaline) conditions. In particular, the depolymerization is preferably carried out in the presence of a glycol-based compound, as described below.

[0030] On the other hand, the recycled cyclic carbonate composition 1 The mass ratio of the alkylene carbonate, as measured by H NMR, may be 95% by mass to 98.5% by mass, or 95.11% by mass to 98.46% by mass, or 95.5% by mass to 98.5% by mass, or 96% by mass to 98.5% by mass, or 97% by mass to 98.5% by mass, or 98% by mass to 98.5% by mass, relative to the total mass of the composition.

[0031] The aforementioned 1 The method for measuring the mass ratio of alkylene carbonate measured by H NMR is not particularly limited, and for example, the mass ratio of ethylene carbonate can be determined by the following Equation 1.

[0032]

number

[0033] In the above formula 1, MW EC is the molecular weight of ethylene carbonate (EC), MW EG is the molecular weight of ethylene glycol (EG), MW BPA is the molecular weight of bisphenol A (BPA), MW PTBP is the molecular weight of 4-tert-butylphenol (PTBP), MW MHE-BPA is the molecular weight of monohydroxyethyl-bisphenol A (MHE-BPA), Mol.eq EC I EC / H EC and I EC (S EC ) / [(SPTBP )+(S MHE-BPA )+(S BPA )+(S EG )+(S EC )], S EC is the peak integral value of 4.48 ppm (s, 2CH2) of ethylene carbonate (EC), S EG is the peak integral value of ethylene glycol (EG) at 3.42 ppm (d, 2CH2), S BPA is the peak integral value of 6.67 ppm (d, 4CH) of bisphenol A (BPA), S PTBP is the peak integration value of 6.60 ppm (d, 2CH) of 4-tert-butylphenol (PTBP), S MHE-BPA is the peak integral value of 6.85 ppm (d, 2CH) of monohydroxyethyl-bisphenol A (MHE-BPA), H EC is the hydrogen number of ethylene carbonate (EC), Mol.eq EG I EG / H EG and I EG (S EG ) / [(S PTBP )+(S MHE-BPA )+(S BPA )+(S EG )+(S EC )], H EG is the hydrogen number of ethylene glycol (EG), Mol.eq BPA I BPA / H BPA and I BPA (S BPA ) / [(S PTBP )+(S MHE-BPA )+(S BPA )+(S EG )+(S EC )], H BPA is the hydrogen number of bisphenol A (BPA), Mol.eq PTBP I PTBP / H PTBP and I PTBP (S PTBP ) / [(S PTBP )+(S MHE-BPA )+(S BPA )+(S EG )+(S EC )], H PTBP is the number of hydrogen atoms in 4-tert-butylphenol (PTBP), Mol.eq MHE-BPA I MHE-BPA / H MHE-BPA and I MHE-BPA (S MHE-BPA ) / [(S PTBP )+(S MHE-BPA )+(S BPA )+(S EG )+(S EC )], H MHE-BPA is the hydrogen number of monohydroxyethyl-bisphenol A (MHE-BPA).

[0034] The aforementioned 1 Specific methods, conditions, devices, etc. for H NMR can be applied without limitation to a variety of previously known methods.

[0035] Thus, in the recycled cyclic carbonate composition of the one embodiment, 1 The mass ratio measured by H NMR significantly increased to 95% to 98.5% by mass of the total mass of the composition, significantly reducing the ratio of impurities other than alkylene carbonate, which is the main target substance for recovery. This allows for the realization of excellent physical properties when used in a variety of applications (e.g., solvents for polymers, synthetic fuels for carbonate esters, liquid electrolyte organic solvents for electric vehicle batteries, etc.).

[0036] More specifically, the recycled cyclic carbonate composition of one embodiment further contains a phenolic compound, 1The mass ratio of the phenolic compound measured by H NMR may be 5% by mass or less, or 4.5% by mass or less, or 4.35% by mass or less, or 4% by mass or less, or 3% by mass or less, or 2% by mass or less, or 1.5% by mass or less, or 1.2% by mass or less, or 0.01% by mass or more, or 1.1% by mass or more, based on the total mass of the composition. The upper limit and lower limit numerical ranges can be combined to satisfy the numerical range from the lower limit to the upper limit. As an example of the numerical range from the lower limit to the upper limit, the recycled cyclic carbonate composition is 1 The mass ratio of the phenolic compound measured by 1 H NMR may be 0.01 mass % to 5 mass % relative to the total mass of the composition.

[0037] The aforementioned 1 Examples of methods for measuring the mass ratios of phenolic compounds measured by H NMR are not particularly limited. For example, the mass ratio of bisphenol A can be calculated using the following formula 3, the mass ratio of 4-tert-butylphenol can be calculated using the following formula 4, and the mass ratio of monohydroxyethyl-bisphenol A can be calculated using the following formula 5, and then the mass ratios can be calculated by summing them up.

[0038]

number

[0039]

number

[0040]

number

[0041] The explanation of each of the formulas 3 to 5 includes all of the contents described above for the formula 1.

[0042] The phenolic compound can include one or more compounds selected from the group consisting of bisphenol A, 4-tert-butylphenol, and monohydroxyethyl-bisphenol A. That is, the phenolic compound can include one type of bisphenol A, one type of 4-tert-butylphenol, one type of monohydroxyethyl-bisphenol A, or a mixture of two or more types thereof.

[0043] More specifically, in the recycled cyclic carbonate composition of one embodiment, the mass ratio of the phenol compound relative to 100 parts by mass of the alkylene carbonate may be 0.01 to 5 parts by mass, or 0.01 to 4.5 parts by mass, or 0.01 to 4.35 parts by mass, or 0.01 to 4 parts by mass, or 0.01 to 3 parts by mass, or 0.01 to 2 parts by mass, or 0.01 to 1.5 parts by mass, or 0.01 to 1.2 parts by mass.

[0044] Thus, in the recycled cyclic carbonate composition of one embodiment, 1 The mass ratio of the phenolic compounds measured by H NMR is significantly reduced to 5% by mass or less relative to the total mass of the composition, which significantly reduces the ratio of impurities other than alkylene carbonate, the main target material for recovery. This allows for the realization of excellent physical properties when used in a variety of applications (e.g., solvents for polymers, synthetic fuels for carbonate esters, liquid electrolyte organic solvents for electric vehicle batteries, etc.).

[0045] Conversely, if the mass ratio of the phenolic compound is excessively increased, the viscosity of the alkylene carbonate may be high and the solubility of the salt may be reduced, which may result in technical problems such as reduced ionic conductivity and reduced chemical stability when applied to a battery.

[0046] Moreover, the recycled cyclic carbonate composition of the above-mentioned one embodiment further contains alkylene glycol, 1The mass proportion of alkylene glycol, as measured by H NMR, may be 0.1% to 3% by mass, or 0.38% to 2.49% by mass, or 0.1% to 2.5% by mass, or 0.1% to 2% by mass, or 0.1% to 1% by mass, or 0.1% to 0.5% by mass, or 0.1% to 0.4% by mass, relative to the total mass of the composition.

[0047] The aforementioned 1 The method for measuring the mass ratio of alkylene glycol measured by H NMR is not particularly limited, and for example, the mass ratio of ethylene glycol can be determined by the following Equation 2.

[0048]

number

[0049] In the above Equation 2, the explanation of each calculation formula includes all the contents described above in the above Equation 1.

[0050] The alkylene glycol may include ethylene glycol.

[0051] More specifically, in the recycled cyclic carbonate composition of the above embodiment, the mass ratio of alkylene glycol relative to 100 parts by mass of alkylene carbonate may be 0.1 to 3 parts by mass, or 0.1 to 2.6 parts by mass, or 0.1 to 2.5 parts by mass, or 0.1 to 2 parts by mass, or 0.1 to 1 part by mass, or 0.1 to 0.5 parts by mass, or 0.1 to 0.4 parts by mass.

[0052] Thus, in the recycled cyclic carbonate composition of one embodiment, 1The mass ratio of the alkylene glycol measured by H NMR is extremely reduced to 0.1% by mass to 3% by mass relative to the total mass of the composition, which significantly reduces the ratio of impurities other than alkylene carbonate, which is the main target substance for recovery. This allows the realization of excellent physical properties when used in various applications (e.g., solvents for polymers, synthetic fuels for carbonate esters, liquid electrolyte organic solvents for electric vehicle batteries, etc.).

[0053] On the other hand, if the mass ratio of the alkylene glycol is excessively increased, it may be difficult to control the moisture content of the alkylene carbonate, which may result in a technical problem of leakage current.

[0054] Furthermore, the recycled cyclic carbonate composition of one embodiment further contains a phenolic compound and an alkylene glycol, and the mass ratio of the phenolic compound relative to 100 parts by mass of the alkylene glycol may be 30 parts by mass to 1,000 parts by mass, or 50 parts by mass to 1,000 parts by mass, or 100 parts by mass to 1,000 parts by mass, or 300 parts by mass to 1,000 parts by mass, or 30 parts by mass to 950 parts by mass, or 30 parts by mass to 900 parts by mass, or 30 parts by mass to 860 parts by mass, or 30 parts by mass to 500 parts by mass.

[0055] Meanwhile, the recycled cyclic carbonate composition may have a calcium ion weight ratio measured using ion chromatography of 0.05 ppm to 0.4 ppm, or 0.1 ppm to 0.3 ppm, or 0.2 ppm to 0.3 ppm, or 0.1 ppm to 0.2 ppm, based on 1 g of the composition.

[0056] The recycled cyclic carbonate composition may also have a chloride ion weight ratio measured using ion chromatography of 5.1 ppm to 20 ppm, or 7 ppm to 20 ppm, or 10 ppm to 20 ppm, or 10 ppm to 15 ppm, or 10 ppm to 12 ppm, based on 1 g of the composition.

[0057] Furthermore, the recycled cyclic carbonate composition may have a total ion concentration of 300 ppm or less, or 200 ppm or less, or 100 ppm or less, or 50 ppm or less, or 40 ppm or less, or 30 ppm or less, or 20 ppm or less, or 15 ppm or less, or 10 ppm or less, or 1 ppm or more, based on 1 g of the composition, as measured by ion chromatography. The upper and lower limit ranges may be combined to satisfy a range from the lower limit to the upper limit. As an example of the range from the lower limit to the upper limit, the recycled cyclic carbonate composition may have a total ion concentration of 1 ppm to 300 ppm, based on 1 g of the composition, as measured by ion chromatography.

[0058] The recycled cyclic carbonate composition has a total concentration of all ions measured using ion chromatography of 300 ppm or less, or 200 ppm or less, or 100 ppm or less, or 50 ppm or less, or 40 ppm or less, or 30 ppm or less, or 20 ppm or less, or 15 ppm or less, or 10 ppm or less per gram of the composition, thereby enabling the recycled cyclic carbonate composition to be used as an electrolyte and achieve excellent effects.

[0059] On the other hand, if the total concentration of all ions measured using ion chromatography per gram of the recycled cyclic carbonate composition increases excessively, technical problems such as electrode corrosion due to ionic impurities may occur.

[0060] The method for measuring the weight ratio of ionic impurities in the recycled cyclic carbonate composition of the embodiment is not particularly limited, and can be, for example, ion chromatography (IC). The specific IC method, conditions, and apparatus can be any of a variety of previously known methods, conditions, and apparatuses. However, as an example, (1) Main Column: IonPac AS18 analytical (4 × 250 mm), (2) Guard Column: Ion AG18 guard (4 × 50 mm), (3) Eluent Type: KOH (30.5 mM), (4) Eluent Flow Rate: 1 mL / min, (5) Detector: Suppressed Conductivity Detector, (6) SRS Current: 76 mA, (7) Injection Volume: 20 μl, and (8) Isocratic / Gradient Conditions: Measurement can be performed under isocratic conditions.

[0061] In this way, in the recycled cyclic carbonate composition of the one embodiment, the weight ratio of ionic impurities other than alkylene carbonate, which is the main target substance for recovery, is significantly reduced, making it possible to achieve excellent physical properties.

[0062] Meanwhile, the recycled cyclic carbonate composition may have a peak area ratio of the alkylene carbonate measured by GC-MS of 87 area% to 99.99 area%, or 90 area% to 99.99 area%, or 95 area% to 99.99 area%, or 97 area% to 99.99 area% relative to the total peak area. In this way, in the recycled cyclic carbonate composition of one embodiment, the peak area ratio of the alkylene carbonate measured by GC-MS is significantly increased to 87 area% to 99.99 area% relative to the total peak area, significantly reducing the ratio of impurities other than alkylene carbonate, which is the main target material for recovery. This allows the composition to achieve excellent physical properties when used in a variety of applications (e.g., solvents for polymers, synthetic fuels for carbonate esters, liquid electrolyte organic solvents for electric vehicle batteries, etc.).

[0063] Furthermore, the recycled cyclic carbonate composition may have a peak area ratio of the phenolic compound measured by GC-MS of 0.01 area% to 12 area%, or 0.01 area% to 11 area%, or 0.01 area% to 10 area%, or 0.01 area% to 5 area%, or 0.01 area% to 4 area%, or 0.01 area% to 3 area% relative to the total peak area. The phenolic compound may include one or more compounds selected from the group consisting of bisphenol A, 4-tert-butylphenol, and monohydroxyethyl-bisphenol A. That is, the phenolic compound may include one type of bisphenol A, one type of 4-tert-butylphenol, one type of monohydroxyethyl-bisphenol A, or a mixture of two or more of these.

[0064] The method for measuring the peak area ratios of the phenolic compounds measured by GC-MS is not particularly limited, and for example, the peak area ratios of bisphenol A, 4-tert-butylphenol, and monohydroxyethyl-bisphenol A can be determined separately and summed up.

[0065] More specifically, ethylene carbonate (EC) exhibits a peak at a retention time of 8 to 11 minutes, bisphenol A (BPA) exhibits a peak at a retention time of 24 to 26 minutes, 4-tert-butylphenol (PTBP) exhibits a peak at a retention time of 14 to 16 minutes, and monohydroxyethyl-bisphenol A (MHE-BPA) exhibits a peak at a retention time of 26 to 28 minutes.

[0066] The specific method, conditions, and equipment for the gas chromatography-mass spectrometry (GC-MS) can be variously known and can be applied without limitation. However, as an example, the following conditions can be used for measurement: (1) Column: HP-5MS (L: 30 m, ID: 0.25 mm, film: 0.25 μm), (2) Injection volume: 0.2 μl, (3) Inlet temperature: 300°C, spill ratio: 20:1, (4) Column flow: (He) 1 ml / min, (5) Oven temperature: 50°C / 5 min - 10°C / min - 320°C / 15 min (total 47 min), (6) Detector temperature: 300°C, and (7) GC model: Agilent 7890.

[0067] As such, in the recycled cyclic carbonate composition of one embodiment, the ratio of impurities other than alkylene carbonate, which is the main target material for recovery, is significantly reduced, and excellent physical properties can be achieved when used in a variety of applications (e.g., solvents for high molecular weight polymers, synthetic fuels for carbonate esters, liquid electrolyte organic solvents for electric vehicle batteries, etc.).

[0068] The recycled cyclic carbonate composition of one embodiment may further contain small amounts of other additives and solvents. The specific types of additives and solvents are not particularly limited, and various substances widely used in the process of recovering alkylene carbonate by depolymerization of polycarbonate resins can be used without limitation.

[0069] The recycled cyclic carbonate composition of the embodiment may be obtained by the method for producing a recycled cyclic carbonate composition described below. That is, the recycled cyclic carbonate composition of the embodiment corresponds to a resultant product obtained by a depolymerization reaction of a polycarbonate resin, followed by various filtration, purification, washing, and drying processes to obtain only alkylene carbonate, which is a main target substance for recovery, at a high purity.

[0070] 2. Method for producing recycled cyclic carbonate composition According to another embodiment of the present invention, there is provided a method for producing a recycled cyclic carbonate composition, the method including: adding a polycarbonate resin to an organic solvent to prepare a mixed solution; adding an alkylene glycol and an inorganic base catalyst to the mixed solution to depolymerize the polycarbonate resin; removing an aromatic diol compound, an organic solvent, and an alkylene glycol from the depolymerized solution; and recovering an alkylene carbonate from the depolymerized solution from which the aromatic diol compound, the organic solvent, and the alkylene glycol have been removed.

[0071] The present inventors have confirmed through experiments that the method for producing a recycled cyclic carbonate composition according to the other embodiment can achieve high purity and excellent physical properties comparable to those of newly synthesized alkylene carbonates, even though the recycled cyclic carbonate composition is recovered by chemical decomposition of a polycarbonate resin, and can be obtained in high yields, thereby completing the invention.

[0072] Specifically, the present invention makes it possible to decompose polycarbonate with alkylene glycol under mild conditions, thereby stably obtaining alkylene carbonate, which is a highly pure monomer.

[0073] The method for producing a recycled cyclic carbonate composition according to another embodiment may include the steps of: adding a polycarbonate resin to an organic solvent to prepare a mixture; and adding an alkylene glycol and an inorganic base catalyst to the mixture to depolymerize the polycarbonate resin.

[0074] The term "polycarbonate-based resin" refers to any homopolymer or copolymer containing a polycarbonate repeating unit, collectively referring to a reaction product obtained by the polymerization or copolymerization of monomers containing an alkylene carbonate and a carbonate precursor. A homopolymer is synthesized when a single carbonate repeating unit is obtained using only one alkylene carbonate and one carbonate precursor. A copolymer is synthesized when two or more carbonates are contained using one alkylene carbonate and two or more carbonate precursors, two or more alkylene carbonates and one carbonate precursor, or one alkylene carbonate, one carbonate precursor, and one or more other diols. The homopolymer or copolymer may include low molecular weight compounds, oligomers, and polymers within a range of molecular weights.

[0075] The polycarbonate-based resin can be applied regardless of various forms and types, such as new polycarbonate produced by synthesis, recycled polycarbonate produced by a recycling process, or polycarbonate waste.

[0076] In the present invention, specific examples of the alkylene glycol are not particularly limited, and various previously known alkylene glycols can be used without limitation. Examples include ethylene glycol and propylene glycol.

[0077] Meanwhile, the organic solvent may include one or more solvents selected from the group consisting of tetrahydrofuran, methylene chloride, chloroform, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, and dipropyl carbonate, i.e., tetrahydrofuran, methylene chloride, chloroform, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, dipropyl carbonate, or a mixture of two or more thereof.

[0078] Specifically, when methylene chloride is used as the organic solvent, there is an advantage that the dissolving property for polycarbonate is improved, and the reactivity can be improved.

[0079] The weight ratio of the alkylene glycol, organic solvent, and polycarbonate resin is not particularly limited, but for example, the weight ratio of the alkylene glycol to the polycarbonate resin may be 10:1 to 1:10, or 1:1 to 1:10, or 1:1 to 1:5, or 1:1 to 1:2, or 1:1.1 to 1:2.

[0080] The weight ratio of the organic solvent to the polycarbonate resin may be 10:1 to 1:10, or 10:1 to 1:1, or 10:1 to 2:1, or 10:1 to 5:1, or 10:1 to 6:1, or 10:1 to 7:1, or 10:1 to 8:1, or 9:1 to 8:1, or 9:1 to 5:1, or 8:1 to 5:1, or 7:1 to 5:1, or 6:1 to 5:1.

[0081] Furthermore, the weight ratio between the organic solvent and the alkylene glycol may be 20:1 to 1:20, or 1:1 to 20:1, or 5:1 to 20:1, or 5:1 to 15:1, or 5:1 to 11:1.

[0082] Specifically, by mixing the alkylene glycol and the organic solvent within the above range, it is possible to advantageously carry out a required level of depolymerization reaction of the polymer.

[0083] The catalyst is added in an amount of 0.1 to 10 parts by weight, or 0.1 to 5 parts by weight, relative to 100 parts by weight of the polycarbonate resin. Specifically, by including a catalyst in the above content range, there is an advantage that an economical catalytic reaction can be promoted.

[0084] The catalyst may be an inorganic base catalyst. The inorganic base catalyst refers to a non-ionic inorganic compound having basicity, specifically, sodium hydroxide (NaOH) or potassium hydroxide (KOH), preferably sodium hydroxide (NaOH), but is not limited thereto. The use of the inorganic base catalyst has the advantage that the decomposition reaction is carried out under mild conditions, which is economical.

[0085] Meanwhile, the step of adding alkylene glycol and an inorganic base catalyst to the mixed solution to depolymerize the polycarbonate resin may involve stirring at 20°C to 100°C, or 50°C to 100°C, or 60°C to 100°C, or 70°C to 100°C for 1 hour to 24 hours, or 1 hour to 12 hours, or 1 hour to 8 hours.

[0086] Specifically, the above conditions are milder process conditions than the existing pressurized / high temperature process, and stirring under these conditions allows the process to be carried out in a milder process than the existing pressurized / high temperature process. In particular, stirring at 70°C to 100°C for 1 to 12 hours has the advantage of providing the most efficient results in terms of reproducibility and stability.

[0087] Meanwhile, the method for producing a recycled cyclic carbonate composition according to another embodiment may include removing the aromatic diol compound, the organic solvent, and the alkylene glycol from the depolymerized solution. By removing the aromatic diol compound, the organic solvent, and the alkylene glycol from the depolymerized solution, the organic solvent, the alkylene glycol, and the aromatic diol compound are all separated, and the remaining alkylene carbonate is obtained as a main product.

[0088] The step of removing the aromatic diol compound, the organic solvent, and the alkylene glycol from the depolymerized solution may include the steps of: removing the aromatic diol compound from the depolymerized solution; removing the organic solvent from the depolymerized solution; and removing the alkylene glycol from the depolymerized solution.

[0089] The order of the steps of removing the aromatic diol compound from the depolymerized solution, removing the organic solvent from the depolymerized solution, and removing the alkylene glycol from the depolymerized solution is not particularly limited, but for example, the steps may be performed in the order of: removing the aromatic diol compound from the depolymerized solution; removing the organic solvent from the depolymerized solution; and removing the alkylene glycol from the depolymerized solution.

[0090] More specifically, the step of removing the aromatic diol compound from the depolymerized solution may include the steps of crystallizing the aromatic diol compound formed by the depolymerization; and filtering the aromatic diol compound crystals.

[0091] The aromatic diol compound is recovered from the polycarbonate resin, which means that the aromatic diol compound is also obtained as a result of recovery from the polycarbonate resin to obtain the recycled cyclic carbonate composition of the other embodiment.

[0092] Specifically, the term "recovered from a polycarbonate-based resin" means that the polycarbonate-based resin is obtained by depolymerization of the polycarbonate-based resin. The depolymerization can be carried out under acidic, neutral, or basic conditions, and can particularly proceed under basic (alkaline) conditions. In particular, the depolymerization is preferably carried out in the presence of a glycol-based compound, as described below.

[0093] Specific examples of the aromatic diol compound include bis(4-hydroxyphenyl)methane, bis(4-hydroxyphenyl)ether, bis(4-hydroxyphenyl)sulfone, bis(4-hydroxyphenyl)sulfoxide, bis(4-hydroxyphenyl)sulfide, bis(4-hydroxyphenyl)ketone, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), 2,2-bis(4-hydroxyphenyl)butane, 1,1-bis(4-hydroxyphenyl)cyclohexane (bis Examples of aromatic diol compounds include 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3,5-dibromophenyl)propane, 2,2-bis(4-hydroxy-3,5-dichlorophenyl)propane, 2,2-bis(4-hydroxy-3-bromophenyl)propane, 2,2-bis(4-hydroxy-3-chlorophenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, and mixtures of two or more thereof. Preferably, the aromatic diol compound may be 2,2-bis(4-hydroxyphenyl)propane (bisphenol A).

[0094] The step of crystallizing the aromatic diol compound formed by the depolymerization can be carried out by adding the depolymerization solution to water. When the depolymerization solution is added to water, the aromatic diol compound contained in the depolymerization solution is crystallized due to the difference in solubility. The crystallization conditions are not particularly limited, and various known crystallization conditions, methods, and devices can be applied without limitation.

[0095] Among the aromatic diol compound, alkylene glycol, and alkylene carbonate contained in the depolymerization solution, the aromatic diol compound forms crystals, while the remaining substances remain dissolved. At this time, the crystallized aromatic diol compound is removed by filtration, thereby removing the aromatic diol compound and obtaining alkylene carbonate.

[0096] In the step of filtering the aromatic diol compound crystals, the crystallized aromatic diol compound may be filtered under reduced pressure. This allows the aromatic diol compound contained in the depolymerization solution to be effectively removed. The filtering conditions are not particularly limited, and various previously known filtering conditions, methods, and devices may be used without limitation.

[0097] The step of removing the organic solvent from the depolymerization solution may include distilling the organic solvent. The organic solvent may include one or more solvents selected from the group consisting of tetrahydrofuran, methylene chloride, chloroform, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, and dipropyl carbonate. That is, the organic solvent may include tetrahydrofuran, methylene chloride, chloroform, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, dipropyl carbonate, or a mixture of two or more thereof. Specifically, when methylene chloride is used as the organic solvent, it has the advantage of improving the solubility of polycarbonate and thereby improving reactivity.

[0098] The distillation temperature is adjusted to a temperature lower than the boiling point of the alkylene carbonate and higher than the boiling point of the organic solvent, so that the alkylene carbonate remains without being distilled and the organic solvent can be removed by distillation. Other distillation conditions are not particularly limited, and various previously known distillation conditions, methods, and apparatuses can be applied without limitation.

[0099] Specifically, the step of distilling the organic solvent can be carried out at a temperature of 40°C to 80°C, or 40°C to 70°C, or 40°C to 60°C, or 40°C to 50°C, and a pressure of 100 psi to 200 psi, or 120 psi to 180 psi, or 140 psi to 160 psi.

[0100] The step of removing the alkylene glycol from the depolymerization solution may include adding the depolymerization solution to the solution separated into an aqueous layer and an organic solvent layer, and removing the alkylene glycol dissolved in the aqueous layer. The organic solvent may include one or more solvents selected from the group consisting of tetrahydrofuran, methylene chloride, chloroform, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, and dipropyl carbonate. That is, the organic solvent may include tetrahydrofuran, methylene chloride, chloroform, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, dipropyl carbonate, or a mixture of two or more thereof. Specifically, using methylene chloride as the organic solvent has the advantage of improving the solubility of polycarbonate and thereby improving reactivity.

[0101] Among the alkylene glycol and alkylene carbonate contained in the depolymerization solution, the alkylene glycol is relatively hydrophilic and can be dissolved in the aqueous layer, while the alkylene carbonate is dissolved in the organic solvent layer, allowing for phase separation. At this time, the separated aqueous layer is removed to obtain the organic solvent layer, and the alkylene glycol is removed to obtain the alkylene carbonate.

[0102] Meanwhile, the step of removing the aromatic diol compound, the organic solvent, and the alkylene glycol from the depolymerized solution may further include the step of removing phenolic impurities derived from the aromatic diol compound formed by the depolymerization using an adsorbent. The phenolic impurities may include one or more compounds selected from the group consisting of bisphenol A, 4-tert-butylphenol, and monohydroxyethyl-bisphenol A.

[0103] Examples of the adsorbent include activated carbon, charcoal, celite, acid clay, or a mixture thereof. The activated carbon is a black carbon material with micropores produced by subjecting a raw material to a carbonization process at about 500°C and an activated carbon process at about 900°C. The activated carbon is not particularly limited, and various activated carbons can be used without limitation, such as plant-based, coal-based, petroleum-based, and waste-based activated carbons, depending on the type of raw material.

[0104] By applying the adsorption purification step using an adsorbent, not only can the alkylene carbonate, which is the main synthetic target substance in the present invention, be secured at a high purity, but the contents of other impurities can also be significantly reduced.

[0105] The adsorption purification conditions using the adsorbent are not particularly limited, and various conventionally known adsorption purification conditions can be used without limitation. However, for example, the amount of adsorbent added may be 40% by weight to 60% by weight relative to the polycarbonate resin, the adsorption time may be 0.1 hours to 5 hours, and the adsorption method may be stirring adsorption or a laboratory adsorption tower.

[0106] Meanwhile, the method for producing a recycled cyclic carbonate composition according to another embodiment may include recovering alkylene carbonate from the depolymerized solution from which the aromatic diol compound, the organic solvent, and the alkylene glycol have been removed.

[0107] The step of recovering the alkylene carbonate from the depolymerized solution from which the aromatic diol compound, the organic solvent, and the alkylene glycol have been removed may include distilling the depolymerized solution from which the aromatic diol compound, the organic solvent, and the alkylene glycol have been removed.

[0108] In the step of distilling the depolymerized solution from which the aromatic diol compound, the organic solvent, and the alkylene glycol have been removed, the organic solvent remaining in the depolymerized solution from which the aromatic diol compound, the organic solvent, and the alkylene glycol have been removed may be removed by distillation.

[0109] The distillation temperature is adjusted to a temperature lower than the boiling point of the alkylene carbonate and higher than the boiling point of the organic solvent, so that the alkylene carbonate remains without being distilled and the organic solvent can be removed by distillation. Other distillation conditions are not particularly limited, and various previously known distillation conditions, methods, and apparatuses can be applied without limitation.

[0110] Specifically, the step of distilling the organic solvent can be carried out at a temperature of 40°C to 80°C, or 40°C to 70°C, or 40°C to 60°C, or 40°C to 50°C, and a pressure of 100 psi to 200 psi, or 120 psi to 180 psi, or 140 psi to 160 psi. [Effects of the Invention]

[0111] According to the present invention, there can be provided a recycled cyclic carbonate composition and a method for producing the same, which can ensure high purity of a cyclic carbonate compound recovered by recycling polycarbonate resins through chemical decomposition. DETAILED DESCRIPTION OF THE INVENTION

[0112] The present invention will be described in more detail in the following examples, but the following examples are merely illustrative of the present invention and are not intended to limit the scope of the present invention.

[0113] <Example> Example 1 166.67 g of methylene chloride and 30 g of polycarbonate were placed in a 500 ml three-neck flask and stirred.

[0114] Thereafter, 16.37 g of ethylene glycol and 0.169 g of sodium hydroxide (NaOH) as a catalyst were added, and the depolymerization reaction was allowed to proceed at 100° C. for 3 hours.

[0115] After the depolymerization reaction was completed, the depolymerization reaction product was added to water to crystallize bisphenol A, which was then filtered under reduced pressure to remove bisphenol A. The resulting filtrate was then distilled at 40°C and 150 psi to remove methylene chloride, and then treated with charcoal to remove phenolic impurities.

[0116] The resulting filtrate was then separated into layers using water and methylene chloride to remove the aqueous layer containing ethylene glycol and obtain a methylene chloride layer containing ethylene carbonate. The resulting methylene chloride solution was distilled at 40°C and 150 psi to remove the methylene chloride and obtain ethylene carbonate, thereby producing a recycled cyclic carbonate composition.

[0117] Example 2 A recycled cyclic carbonate composition was prepared in the same manner as in Example 1, except that acid clay was used instead of charcoal.

[0118] Example 3 A recycled cyclic carbonate composition was produced in the same manner as in Example 1, except that 19.65 g of ethylene glycol was used.

[0119] Example 4 A recycled cyclic carbonate composition was produced in the same manner as in Example 1, except that 22.92 g of ethylene glycol was used.

[0120] Example 5 A recycled cyclic carbonate composition was produced in the same manner as in Example 1, except that 0.127 g of sodium hydroxide (NaOH) was used.

[0121] Example 6 A recycled cyclic carbonate composition was produced by obtaining propylene carbonate in the same manner as in Example 1, except that 26.76 g of propylene glycol was used instead of ethylene glycol.

[0122] Example 7 A recycled cyclic carbonate composition was produced by obtaining propylene carbonate in the same manner as in Example 1, except that 20.07 g of propylene glycol was used instead of ethylene glycol.

[0123] <Comparative Example> (Comparative Example 1) 60 ml of methylene chloride, 30 ml of ethylene glycol, and 0.6 g of sodium hydroxide (NaOH) were placed in a 250 ml three-neck flask and stirred.

[0124] Thereafter, 30 g of waste polycarbonate was added and stirred at 40°C for 5 hours.

[0125] After the reaction was completed, ethylene glycol was separated by distillation, and toluene was added to separate bisphenol A, thereby obtaining ethylene carbonate and preparing a recycled cyclic carbonate composition.

[0126] (Comparative Example 2) Toluene (60 ml), ethylene glycol (30 ml), and sodium hydroxide (NaOH) (0.6 g) were placed in a 250 ml three-neck flask and stirred.

[0127] Thereafter, 30 g of waste polycarbonate was added and stirred at 60°C for 5 hours.

[0128] After the reaction was completed, ethylene glycol was separated by distillation, and toluene was added to separate bisphenol A, thereby obtaining ethylene carbonate and preparing a recycled cyclic carbonate composition.

[0129] (Comparative Example 3) 120 g of phenol and 40 g of polycarbonate were placed in a 500 ml three-neck flask and stirred.

[0130] Thereafter, 17.5 g of ethylene glycol and 1 g of sodium hydroxide (NaOH) as a catalyst were added, and the depolymerization reaction was allowed to proceed at 80° C. for 5 hours.

[0131] After the depolymerization reaction was completed, 100 g of toluene was added to the depolymerization product, which was then neutralized with hydrochloric acid. The phenol was removed by distillation at 120°C and 150 psi, and then phenolic impurities were removed by charcoal treatment. The charcoal-treated material was then added to water for crystallization, and bisphenol A was removed by filtration under reduced pressure.

[0132] The resulting filtrate was then separated into layers using water and methylene chloride to remove the aqueous layer containing ethylene glycol and obtain a methylene chloride layer containing ethylene carbonate. The resulting methylene chloride solution was distilled at 40°C and 150 psi to remove the methylene chloride and obtain ethylene carbonate, thereby producing a recycled cyclic carbonate composition.

[0133] <Experimental Example> The properties of the recycled cyclic carbonate compositions obtained in the above Examples and Comparative Examples were measured by the following methods, and the results are shown in Tables 1 to 3.

[0134] 1.NMR analysis The recycled cyclic carbonate composition was collected as a sample and diluted with DMSO-d6 to a concentration of 10 mg / ml, 1 The integral values ​​of the NMR peaks detected by the H NMR device were measured, and the mass ratios of ethylene carbonate (EC), ethylene glycol (EG), bisphenol A (BPA), 4-tert-butylphenol (PTBP), and monohydroxyethyl-bisphenol A (MHE-BPA) contained in the sample were calculated using the following formulas 1 to 5.

[0135] Specifically, the peaks targeted were ethylene carbonate (EC) at 4.48 ppm (s, 2CH2), ethylene glycol (EG) at 3.42 ppm (d, 2CH2), bisphenol A (BPA) at 6.67 ppm (d, 4CH), 4-tert-butylphenol (PTBP) at 6.60 ppm (d, 2CH), and monohydroxyethyl-bisphenol A (MHE-BPA) at 6.85 ppm (d, 2CH).

[0136]

number

[0137] In the above formula 1, MW EC is the molecular weight of ethylene carbonate (EC), MW EG is the molecular weight of ethylene glycol (EG), MW BPA is the molecular weight of bisphenol A (BPA), MW PTBP is the molecular weight of 4-tert-butylphenol (PTBP), MW MHE-BPA is the molecular weight of monohydroxyethyl-bisphenol A (MHE-BPA), Mol.eq EC I EC / H EC and I EC (S EC ) / [(S PTBP )+(S MHE-BPA )+(S BPA )+(S EG )+(S EC)], S EC is the peak integral value of 4.48 ppm (s, 2CH2) of ethylene carbonate (EC), S EG is the peak integral value of ethylene glycol (EG) at 3.42 ppm (d, 2CH2), S BPA is the peak integral value of 6.67 ppm (d, 4CH) of bisphenol A (BPA), S PTBP is the peak integration value of 6.60 ppm (d, 2CH) of 4-tert-butylphenol (PTBP), S MHE-BPA is the peak integral value of 6.85 ppm (d, 2CH) of monohydroxyethyl-bisphenol A (MHE-BPA), H EC is the hydrogen number of ethylene carbonate (EC), Mol.eq EG I EG / H EG and I EG (S EG ) / [(S PTBP )+(S MHE-BPA )+(S BPA )+(S EG )+(S EC )], H EG is the hydrogen number of ethylene glycol (EG), Mol.eq BPA I BPA / H BPA and I BPA (S BPA ) / [(S PTBP )+(S MHE-BPA )+(S BPA )+(S EG )+(S EC )], H BPA is the hydrogen number of bisphenol A (BPA), Mol.eq PTBP I PTBP / H PTBP and I PTBP (S PTBP ) / [(S PTBP )+(S MHE-BPA )+(SBPA )+(S EG )+(S EC )], H PTBP is the number of hydrogen atoms in 4-tert-butylphenol (PTBP), Mol.eq MHE-BPA I MHE-BPA / H MHE-BPA and I MHE-BPA (S MHE-BPA ) / [(S PTBP )+(S MHE-BPA )+(S BPA )+(S EG )+(S EC )], H MHE-BPA is the hydrogen number of monohydroxyethyl-bisphenol A (MHE-BPA).

[0138]

number

[0139]

number

[0140]

number

[0141]

number

[0142] [Table 1]

[0143] As shown in Table 1, the recycled cyclic carbonate compositions obtained in the Examples had a higher ethylene carbonate (EC) content than the Comparative Examples, and the contents of phenolic impurities such as bisphenol A (BPA), 4-tert-butylphenol (PTBP), and monohydroxyethyl-bisphenol A (MHE-BPA) were reduced.

[0144] 2.GC-MS analysis The recycled cyclic carbonate composition was collected as a sample and diluted with methanol to a concentration of 10 mg / ml. Gas chromatography mass spectrometry (GC-MS) spectra were obtained using a GC / MS device under the following conditions, and the peak area ratios of ethylene carbonate (EC), bisphenol A (BPA), 4-tert-butylphenol (PTBP), and monohydroxyethyl-bisphenol A (MHE-BPA) contained in the sample were calculated.

[0145] Specifically, the target peaks were ethylene carbonate (EC) at a retention time of 8 to 11 minutes, bisphenol A (BPA) at a retention time of 24 to 26 minutes, 4-tert-butylphenol (PTBP) at a retention time of 14 to 16 minutes, and monohydroxyethyl-bisphenol A (MHE-BPA) at a retention time of 26 to 28 minutes.

[0146] <Gas chromatography (GC) conditions> (1)Column:HP-5MS(L:30m, ID:0.25mm, film:0.25μm) (2) Injection volume: 0.2 μl (3) Inlet, Temp.:300℃, spill ratio:20:1 (4) Column flow: (He) 1 ml / min (5)Oven temp.:50℃ / 5min-10℃ / min-320℃ / 15min(Total 47min) (6) Detector Temp.: 300℃ (7) GC Model: Agilent 7890

[0147] [Table 2]

[0148] As shown in Table 2, the recycled cyclic carbonate compositions obtained in the examples had a higher ethylene carbonate (EC) content than the comparative examples, and the content of phenolic impurities such as bisphenol A (BPA), 4-tert-butylphenol (PTBP), and monohydroxyethyl-bisphenol A (MHE-BPA) was reduced.

[0149] 3. Ion Analysis The recycled cyclic carbonate composition was collected as a sample and analyzed by inductively coupled plasma mass spectrometry (ICP-MS) and ion chromatography (IC) under the following conditions to measure the weight ratio (unit: ppm) of ions contained in the sample based on 1 g.

[0150] <Inductively coupled plasma mass spectrometer (ICP-MS) conditions> (1) Analysis conditions (aqueous sample, no gas mode) (2) RF power (W): 1600 (3) RF Matching (V): 1.6 (4) Sample Depth (nm) 8 (5) Carrier Gas (L / min): 0.7 (6) Option Gas (%): 0 (7) Storage Temperature (℃): 2 (8) Makeup Gas (L / min): 0.52 <Ion chromatography (IC) conditions> (1)Main Column:IonPac AS18 analytical(4×250mm) (2)Guard Coulmn:Ion AG18 guard(4×50mm) (3) Eluent type: KOH (30.5 mM) (4) Eluent flow rate: 1 mL / min (5) Detector: Suppressed Conductivity Detector (6) SRS Current: 76mA (7) Injection volume: 20 μl (8) Isocratic / Gradient condition: isocratic

[0151] [Table 3]

[0152] As shown in Table 3, it was confirmed that the recycled cyclic carbonate compositions obtained in the examples had reduced individual ion contents and the total content of all ions compared to the comparative examples.

Claims

1. A composition comprising an alkylene carbonate, Further comprising a phenolic compound in a mass proportion of 5% or less by mass based on the total mass of the recycled cyclic carbonate composition as measured by 1 H NMR; A method for producing a recycled cyclic carbonate composition, characterized in that the recycled cyclic carbonate composition is recovered from a polycarbonate-based resin, comprising: adding a polycarbonate-based resin to an organic solvent to prepare a mixed solution; adding an alkylene glycol and an inorganic base catalyst to the mixture to depolymerize the polycarbonate-based resin, thereby obtaining a depolymerized solution; removing the aromatic diol compound, the organic solvent, and the alkylene glycol from the depolymerized solution; and recovering alkylene carbonate from the depolymerized solution from which the aromatic diol compound, the organic solvent, and the alkylene glycol have been removed; The step of removing the aromatic diol compound, the organic solvent, and the alkylene glycol from the depolymerization solution includes: removing the aromatic diol compound from the depolymerization solution; removing the organic solvent from the depolymerization solution; removing phenolic impurities derived from the aromatic diol compound formed by the depolymerization with an adsorbent; and removing alkylene glycol from the depolymerization solution; The step of removing the aromatic diol compound from the depolymerization solution comprises: Crystallizing the aromatic diol compound formed by the depolymerization; and filtering the aromatic diol compound crystals; removing the organic solvent from the depolymerization solution includes distilling the organic solvent; The step of removing alkylene glycol from the depolymerization solution comprises: adding the depolymerization solution to the solution separated into an aqueous layer and an organic solvent layer, and removing alkylene glycol dissolved in the aqueous layer; The step of recovering alkylene carbonate from the depolymerized solution from which the aromatic diol compound, the organic solvent, and the alkylene glycol have been removed includes: distilling the depolymerized solution from which the aromatic diol compound, the organic solvent, and the alkylene glycol have been removed; the organic solvent comprises methylene chloride; The method for producing a recycled cyclic carbonate composition, wherein the weight ratio between the methylene chloride and the polycarbonate resin is 8:1 to 5:

1.

2. 2. The method for producing a recycled cyclic carbonate composition according to claim 1, wherein the inorganic base catalyst comprises sodium hydroxide or potassium hydroxide.

3. The step of depolymerizing the polycarbonate-based resin by adding an alkylene glycol and an inorganic base catalyst to the mixture includes: The method for producing a recycled cyclic carbonate composition according to claim 1, wherein the mixture is stirred at 20°C to 100°C for 1 hour to 24 hours.

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