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 to Korean Patent Application No. 10-2022-0155347 dated November 18, 2022, Korean Patent Application No. 10-2023-0052249 dated April 20, 2023, Korean Patent Application No. 10-2023-0159224 dated November 16, 2023, and Korean Patent Application No. 10-2023-0159225 dated 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] Polycarbonate is widely used for a variety of purposes, but environmental and health concerns have been continually raised regarding its waste disposal.

[0005] Currently, physical recycling methods are being used, but problems have arisen with this method, such as a deterioration in quality, and research is being conducted into the chemical recycling of polycarbonate.

[0006] The chemical decomposition of polycarbonate refers to obtaining an aromatic diol compound (eg, bisphenol A (BPA)) and a carbonate compound (eg, diethyl carbonate), which are monomers constituting polycarbonate, by decomposing polycarbonate.

[0007] Representative examples of such chemical decomposition include pyrolysis, hydrolysis, and alcoholysis. Among these, alcoholysis is the most common method, but methanolysis has the problem 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 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 an increasing need to develop a method for producing industrially useful cyclic carbonates by chemically decomposing polycarbonate, taking advantage of the fact that carbonate compounds can be obtained by chemically decomposing polycarbonate. Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention provides a recycled cyclic carbonate composition capable of ensuring high purity of a cyclic carbonate compound recovered by recycling a polycarbonate resin 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 method for producing a polyolefin copolymer comprising: 1 The recycled cyclic carbonate composition 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.

[0012] The present specification also provides a method for producing a recycled cyclic carbonate composition, comprising: adding a polycarbonate-based resin to an organic solvent to produce a mixed solution; adding an alkylene glycol and an inorganic base catalyst to the mixed solution to depolymerize the polycarbonate-based 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 the method for producing the same according to specific embodiments of the invention are described in more detail below.

[0014] Unless otherwise expressly stated herein, the terminology used 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 unless the context clearly dictates to the contrary.

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

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

[0018] In the present specification, the term "substituted or unsubstituted" means that the group is 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, alkylthio, arylthio, alkylsulfoxy, arylsulfoxy, silyl, boron, alkyl, cycloalkyl, alkenyl, aryl, aralkyl, aralkenyl, alkylaryl, alkoxysilylalkyl, arylphosphine, or heterocyclic groups containing one or more of N, O, and S atoms, and that two or more of the above-listed substituents are linked to each other. For example, the "substituent with two or more substituents linked to each other" may be a biphenyl group. In other words, the biphenyl group may be an aryl group, and may be interpreted as a substituent with two phenyl groups linked to each other.

[0019] In this specification, an alkyl group is a monovalent functional group derived from an alkane, which 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. In addition, 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-methyl-butyl, 1-ethyl-butyl, 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-ethyl-propyl, 1,1-dimethyl-propyl, 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 substituents are as described above.

[0020] In this specification, the alkylene group is a divalent functional group derived from an alkane, and the above description of the alkyl group is applicable except that the alkyl group is a divalent functional group. For example, the alkylene group may be linear or branched, and may be a methylene group, an ethylene group, a propylene group, an isobutylene group, a sec-butylene group, a tert-butylene group, a pentylene group, a 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 The present invention provides a recycled cyclic carbonate composition, which is characterized in that it further contains a phenol compound having a mass ratio, as measured by H NMR, of 5 mass% or less based on the total mass of the composition and is recovered from a polycarbonate resin.

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

[0024] In other words, the present invention has the technical advantage that a composition containing an alkylene carbonate can be obtained with high purity by recycling a polycarbonate resin through chemical decomposition.

[0025] Specifically, the recycled cyclic carbonate composition of the embodiment is characterized in that it is recovered from a polycarbonate-based resin, which means 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 an alkylene carbonate is also obtained.

[0026] The polycarbonate resin includes all homopolymers or copolymers containing polycarbonate repeating units, and is a general term for reaction products obtained by polymerization or copolymerization of monomers containing alkylene carbonate and carbonate precursor. When it contains one type of carbonate repeating unit obtained by using only one type of alkylene carbonate and one type of carbonate precursor, a homopolymer is synthesized. When it contains two or more types of carbonates using one type of alkylene carbonate and two or more types of carbonate precursors, two or more types of alkylene carbonate and one type of carbonate precursor, or when it contains two or more types of carbonates using one type of alkylene carbonate and one type of carbonate precursor as well as one or more other diols, a copolymer is synthesized. The homopolymer or copolymer may include all low molecular weight compounds, oligomers, and polymers according to the molecular weight range.

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

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

[0029] Specifically, the term "recovered from the polycarbonate-based resin" means that the polycarbonate-based resin is obtained by a depolymerization reaction. The depolymerization reaction may be carried out under acidic, neutral, or basic conditions, and in particular, the depolymerization reaction can be carried out under basic (alkaline) conditions. In particular, the depolymerization reaction 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 is 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 above 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 calculated by the following Equation 1.

[0032]

number

[0033] In the above formula 1, M 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 bisphenol A (BPA) at 6.67 ppm (d, 4CH), S PTBP is the peak integral value of 6.60 ppm (d, 2CH) of 4-tert-butylphenol (PTBP), S MHE-BPA is the peak integral value of monohydroxyethyl-bisphenol A (MHE-BPA) at 6.85 ppm (d, 2CH), 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 number of hydrogen atoms in 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 hydrogen number of 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 above 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 embodiment, 1 The mass ratio measured by H NMR is significantly increased to 95% to 98.5% by mass relative to the total mass of the composition, and the ratio of impurities other than alkylene carbonate, which is the main target substance for recovery, is significantly reduced, which enables the realization of excellent physical properties when used for various applications (e.g., solvent for polymers, synthetic fuel for carbonate esters, liquid electrolyte organic solvent for electric vehicle batteries, etc.).

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

[0037] The above 1 Examples of methods for measuring the mass ratios of phenolic compounds measured by H NMR are not particularly limited, and 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 sum of these.

[0038]

number

[0039]

number

[0040]

number

[0041] In the above formulas 3 to 5, the explanation of each calculation formula includes all of the contents described above in the above formula 1.

[0042] 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 types thereof.

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

[0044] Thus, in the recycled cyclic carbonate composition of the above embodiment, 1 The mass ratio of the phenolic compounds measured by H NMR is extremely reduced to 5 mass% or less based on the total mass of the composition, and therefore the ratio of impurities other than alkylene carbonate, which is the main target material for recovery, is extremely reduced. This allows the realization of excellent physical properties when used for various 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] In addition, the recycled cyclic carbonate composition of the above embodiment further contains an alkylene glycol, 1The mass ratio 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 above 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 calculated 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, the recycled cyclic carbonate composition of the embodiment may have an alkylene glycol mass ratio of 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, relative to 100 parts by mass of alkylene carbonate.

[0052] Thus, in the recycled cyclic carbonate composition of the above embodiment, 1The mass ratio of the alkylene glycol measured by H NMR is extremely reduced to 0.1% by mass to 3% by mass based on the total mass of the composition, and therefore the ratio of impurities other than alkylene carbonate, which is the main target material for recovery, is extremely reduced, and excellent physical properties can be achieved when the composition is used for various applications (e.g., solvent for polymers, synthetic fuel for carbonate esters, liquid electrolyte organic solvent for electric vehicle batteries, etc.).

[0053] Conversely, 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] In addition, the recycled cyclic carbonate composition of the above 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 by 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 have a weight ratio of chloride ions measured by 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 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, or 1 ppm or more based on 1 g of the composition. The upper limit numerical range and the lower limit numerical range can be combined to satisfy the lower limit to upper limit numerical range. As an example of the lower limit to upper limit numerical range, the recycled cyclic carbonate composition may have a total concentration of all ions measured using ion chromatography of 1 ppm to 300 ppm based on 1 g of the composition.

[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, based on 1 g of the composition, so that the recycled cyclic carbonate composition can be used as an electrolyte to achieve excellent effects.

[0059] In contrast, if the total concentration of all ions measured using ion chromatography in the recycled cyclic carbonate composition increases excessively per 1 g of the composition, 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 for example, ion chromatography (IC) analysis can be used. The specific method, conditions, and apparatus of the IC can be applied to various previously known contents without limitation. However, to explain by way of example, (1) Main Column: IonPac AS18 analytical (4 x 250 mm) (2) Guard column: Ion AG18 guard (4 x 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 (8) Isocratic / Gradient conditions: Measurement can be performed under isocratic conditions.

[0061] In this manner, in the recycled cyclic carbonate composition of the 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 realize 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, so that the ratio of impurities other than the alkylene carbonate, which is the main target material for recovery, is significantly reduced, and excellent physical properties can be achieved when the composition is used for various applications (e.g., solvent for polymers, synthetic fuel for carbonate esters, liquid electrolyte organic solvent for electric vehicle batteries, etc.).

[0063] In addition, 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. In other words, 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] An example of a 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) shows a peak at a retention time of 8 to 11 minutes, bisphenol A (BPA) shows a peak at a retention time of 24 to 26 minutes, 4-tert-butylphenol (PTBP) shows a peak at a retention time of 14 to 16 minutes, and monohydroxyethyl-bisphenol A (MHE-BPA) shows a peak at a retention time of 26 to 28 minutes.

[0066] The specific method, conditions, and apparatus of the gas chromatography-mass spectrometry (GC-MS) can be applied without limitation to various previously known contents. However, to explain it as an example, the measurement can be performed under the following conditions: (1) Column: HP-5MS (L: 30m, ID: 0.25mm, film: 0.25μm) (2) Injection volume: 0.2μl (3) Inlet, Temp.: 300℃, spilt ratio: 20:1 (4) Column flow: (He) 1ml / min (5) Oven temp.: 50℃ / 5min-10℃ / min-320℃ / 15min (Total 47min) (6) Detector temp.: 300℃ (7) GC model: Agilent7890.

[0067] In this way, 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 extremely reduced, and excellent physical properties can be achieved when used for various applications (e.g., solvents for 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, and 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-based resins can be used without limitation.

[0069] The recycled cyclic carbonate composition of the embodiment may be obtained by a 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 through various filtration, purification, washing, and drying processes in order to obtain only alkylene carbonate, which is a main target material for recovery, at a high purity after the depolymerization reaction of a polycarbonate-based resin.

[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, comprising: preparing a mixed solution by adding a polycarbonate-based resin to an organic solvent; depolymerizing the polycarbonate-based resin by adding an alkylene glycol and an inorganic base catalyst to the mixed solution; 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 excellent physical properties with a high purity comparable to that of a newly synthesized alkylene carbonate, even though the polycarbonate resin is recovered by recycling through chemical decomposition, and can be obtained in a high yield, thereby completing the invention.

[0072] Specifically, the present invention makes it possible to stably obtain alkylene carbonate, which is a monomer with high purity, by decomposing polycarbonate with alkylene glycol under mild conditions.

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

[0074] The polycarbonate resin includes all homopolymers or copolymers containing polycarbonate repeating units, and is a general term for reaction products obtained by polymerization or copolymerization of monomers containing alkylene carbonate and carbonate precursor. When it contains one type of carbonate repeating unit obtained by using only one type of alkylene carbonate and one type of carbonate precursor, a homopolymer is synthesized. When it contains two or more types of carbonates using one type of alkylene carbonate and two or more types of carbonate precursors, two or more types of alkylene carbonate and one type of carbonate precursor, or when it contains two or more types of carbonates using one type of alkylene carbonate and one type of carbonate precursor as well as one or more other diols, a copolymer is synthesized. The homopolymer or copolymer may include all low molecular weight compounds, oligomers, and polymers according to the molecular weight range.

[0075] The polycarbonate-based resin may 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 alkylene glycols known in the art may be used without limitation. For example, ethylene glycol or propylene glycol may be used.

[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. 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 of these.

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

[0082] Specifically, by mixing the alkylene glycol and the organic solvent within the above range, a desired level of depolymerization reaction of the polymer can be advantageously carried out.

[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 an alkylene glycol and an inorganic base catalyst to the mixed solution to depolymerize the polycarbonate resin may be performed by 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 by performing stirring under the above conditions, the process can be performed in a milder process than the pressurized / high temperature process. In particular, stirring at 70°C to 100°C for 1 to 12 hours has the advantage of being able to obtain 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 depolymerization 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 characterized by being recovered from the polycarbonate resin, which means that the aromatic diol compound is also obtained as a result of proceeding with recovery from the polycarbonate resin in order to obtain the recycled cyclic carbonate composition of the other embodiment.

[0092] Specifically, the term "recovered from the polycarbonate-based resin" means that the polycarbonate-based resin is obtained by a depolymerization reaction. The depolymerization reaction is carried out under acidic, neutral, or basic conditions, and in particular, the depolymerization reaction can proceed under basic (alkaline) conditions. In particular, the depolymerization reaction 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 Phenol Z), 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, or a mixture of two or more of these. 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 may be carried out by pouring the depolymerization solution into water. When the depolymerization solution is poured into 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 previously known crystallization conditions, methods, and devices may 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, and the remaining substances can remain dissolved. At this time, the crystallized aromatic diol compound is removed by filtration, and the alkylene carbonate can be obtained.

[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 filtering conditions, methods, and devices known in the art may be used without limitation.

[0097] The step of removing the organic solvent from the depolymerization solution may include a step of 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, there is an advantage that the dissolving property for polycarbonate is improved, and the reactivity can be improved.

[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 distillation conditions, methods, and devices known in the art 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 alkylene glycol from the depolymerization solution may include adding the depolymerization solution to a 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 of these. Specifically, when methylene chloride is used as the organic solvent, there is an advantage that the dissolving property for polycarbonate is improved, 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, and the alkylene carbonate is dissolved in the organic solvent layer, allowing for layer 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 with 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 having fine pores produced by subjecting a raw material to a carbonization process at about 500°C and an activated carbon process at about 900°C. Examples are not particularly limited, and various activated carbons such as plant-based, coal-based, petroleum-based, and waste-based activated carbons can be used without limitation 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 also the contents of other impurities can 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, as an example, the amount of the 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 lab adsorption tower.

[0106] Meanwhile, the method for producing a recycled cyclic carbonate composition according to another embodiment may include recovering an 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 distillation conditions, methods, and devices known in the art 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. Effect of the Invention

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

[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 Into a 500 ml three-neck flask, 166.67 g of methylene chloride and 30 g of polycarbonate were placed 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 filtrate was then distilled at 40°C and 150 psi to remove methylene chloride, and then treated with charcoal to remove phenol impurities.

[0116] Thereafter, the obtained filtrate was separated into layers using water and methylene chloride to remove the water layer containing ethylene glycol and obtain a methylene chloride layer containing ethylene carbonate. The obtained methylene chloride solution was distilled at 40°C and 150 psi to remove methylene chloride and obtain ethylene carbonate to produce 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 Into a 250 ml three-neck flask, 60 ml of methylene chloride, 30 ml of ethylene glycol, and 0.6 g of sodium hydroxide (NaOH) were placed 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 to prepare 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 to prepare 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, 100g of toluene was added to the depolymerization reaction product, which was then neutralized with hydrochloric acid and distilled at 120℃ and 150 psi to remove phenol, followed by charcoal treatment to remove phenolic impurities. The charcoal-treated material was then added to water to crystallize, and filtered under reduced pressure to remove bisphenol A.

[0132] Thereafter, the obtained filtrate was separated into layers using water and methylene chloride to remove the water layer containing ethylene glycol and obtain a methylene chloride layer containing ethylene carbonate. The obtained methylene chloride solution was distilled at 40°C and 150 psi to remove methylene chloride and obtain ethylene carbonate to produce 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 bisphenol A (BPA) at 6.67 ppm (d, 4CH), S PTBP is the peak integral value of 6.60 ppm (d, 2CH) of 4-tert-butylphenol (PTBP), S MHE-BPA is the peak integral value of monohydroxyethyl-bisphenol A (MHE-BPA) at 6.85 ppm (d, 2CH), 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 number of hydrogen atoms in 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 hydrogen number of 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 composition obtained in the examples had a higher ethylene carbonate (EC) content than the comparative example, 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. A gas chromatography mass spectrometry (GC-MS) spectrum was 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 peaks targeted were those with retention times of 8 to 11 minutes for ethylene carbonate (EC), 24 to 26 minutes for bisphenol A (BPA), 14 to 16 minutes for 4-tert-butylphenol (PTBP), and 26 to 28 minutes for monohydroxyethyl-bisphenol A (MHE-BPA).

[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 composition obtained in the examples had a higher ratio of ethylene carbonate (EC) than the comparative example, and the ratios of phenolic impurities such as bisphenol A (BPA), 4-tert-butylphenol (PTBP), and monohydroxyethyl-bisphenol A (MHE-BPA) were reduced.

[0149] 3. Ion Analysis The recycled cyclic carbonate composition was collected as a sample and analyzed by inductively coupled plasma mass spectrometer (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 of the sample.

[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) S / C Temp(℃):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 composition obtained in the examples had a reduced individual ion content and total ion content compared to the comparative example.

Claims

1. Contains alkylene carbonate, 1 The composition further comprises 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; The present invention relates to a polycarbonate-based resin recovered from a polycarbonate resin. Recycled cyclic carbonate composition.

2. 2. The recycled cyclic carbonate composition according to claim 1, wherein the ratio of the peak area of ​​the alkylene carbonate measured by GC-MS is 87 area % to 99.99 area % relative to the total peak area.

3. 1 2. The recycled cyclic carbonate composition of claim 1, wherein the weight percentage of alkylene carbonate is from 95% to 98.5% by weight based on the total weight of the composition as measured by H NMR.

4. The recycled cyclic carbonate composition according to claim 1, wherein the mass ratio of the phenol compound is 0.01 to 5 parts by mass per 100 parts by mass of the alkylene carbonate.

5. 2. The recycled cyclic carbonate composition of claim 1, wherein the phenolic compound comprises one or more compounds selected from the group consisting of bisphenol A, 4-tert-butylphenol, and monohydroxyethyl-bisphenol A.

6. 2. The recycled cyclic carbonate composition according to claim 1, wherein the peak area ratio of the phenolic compounds measured by GC-MS is 0.01 area % to 12 area % relative to the total peak area.

7. Further comprising an alkylene glycol, 1 2. The recycled cyclic carbonate composition of claim 1, wherein the weight percentage of alkylene glycol is from 0.1% to 3% by weight based on the total weight of the composition as measured by H NMR.

8. The recycled cyclic carbonate composition according to claim 7, wherein the mass ratio of alkylene glycol to 100 parts by mass of alkylene carbonate is 0.1 parts by mass to 3 parts by mass.

9. The recycled cyclic carbonate composition according to claim 7, wherein the mass ratio of the phenol compound is 30 parts by mass to 1000 parts by mass per 100 parts by mass of the alkylene glycol.

10. The recycled cyclic carbonate composition is 2. The recycled cyclic carbonate composition according to claim 1, wherein the weight ratio of calcium ions measured by ion chromatography is 0.05 ppm to 0.4 ppm based on 1 g of the composition.

11. The recycled cyclic carbonate composition is 2. The recycled cyclic carbonate composition according to claim 1, wherein the weight ratio of chloride ions measured by ion chromatography is 5.1 ppm to 20 ppm based on 1 g of the composition.

12. The recycled cyclic carbonate composition is 2. The recycled cyclic carbonate composition of claim 1, wherein the sum of the concentrations of all ions is less than or equal to 300 ppm based on 1 gram of the composition as measured using ion chromatography.

13. adding a polycarbonate-based resin to an organic solvent to prepare a mixture; adding an alkylene glycol and an inorganic base catalyst to the mixture to depolymerize the polycarbonate-based resin; removing the aromatic diol compound, the organic solvent, and the alkylene glycol from the depolymerization solution; and 2. The method for producing the recycled cyclic carbonate composition according to claim 1, further comprising: recovering an alkylene carbonate from the depolymerized solution from which the aromatic diol compound, the organic solvent, and the alkylene glycol have been removed.

14. 14. The method of claim 13, wherein the inorganic base catalyst comprises sodium hydroxide or potassium hydroxide.

15. The method for producing a recycled cyclic carbonate composition according to claim 13, wherein the organic solvent comprises one or more solvents selected from the group consisting of tetrahydrofuran, methylene chloride, chloroform, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate and dipropyl carbonate.

16. 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 13, wherein the mixture is stirred at 20°C to 100°C for 1 hour to 30 hours.

17. 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; and 14. The method of claim 13, comprising the step of: removing alkylene glycol from the depolymerized solution.

18. The step of removing the aromatic diol compound from the depolymerization solution comprises: crystallizing the aromatic diol compound formed by the depolymerization; and 20. The method of claim 17, further comprising: filtering the aromatic diol compound crystals.

19. The step of removing alkylene glycol from the depolymerization solution comprises: The method for producing a recycled cyclic carbonate composition according to claim 17, further comprising the step of adding the depolymerization solution to a solution separated into an aqueous layer and an organic solvent layer, and removing alkylene glycol dissolved in the aqueous layer.

20. The step of recovering an alkylene carbonate from the depolymerization solution from which the aromatic diol compound, the organic solvent, and the alkylene glycol have been removed includes: The method for producing the recycled cyclic carbonate composition according to claim 13, further comprising the step of distilling the depolymerized solution from which the aromatic diol compound, the organic solvent, and the alkylene glycol have been removed.

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