Polyalkylene carbonate resin composition and method for producing same

Abstract

The present invention relates to a polyalkylene carbonate resin composition having excellent thermal stability and a method for producing the same, and provides a polyalkylene carbonate resin composition and a method for producing the same, which comprises a polyalkylene carbonate, an organic acid, and one or more additives selected from antioxidants and hydrolysis inhibitors, and the organic acid is contained in an amount of 0.001 part by weight or more and less than 0.5 parts by weight based on 100 parts by weight of the polyalkylene carbonate.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0060435, filed May 10, 2023, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a polyalkylene carbonate resin composition having excellent thermal stability and a method for producing the same. [Background technology]

[0003] Since the Industrial Revolution, humanity has built modern society by consuming large amounts of fossil fuels, but environmental destruction such as deforestation has led to an increase in the concentration of carbon dioxide in the atmosphere.Since an increase in carbon dioxide concentration causes an increase in the greenhouse effect, it is important to reduce the concentration of carbon dioxide in the atmosphere, which contributes greatly to global warming, and a wide range of research is being conducted, including on carbon dioxide emission regulations and fixation.

[0004] In recent years, polyalkylene carbonate resins obtained by polymerization of carbon dioxide and epoxides have attracted much attention as a type of biodegradable resin. In particular, the process of producing polyalkylene carbonate resins using carbon dioxide can mitigate the problem of global warming by fixing carbon dioxide in the atmosphere, and has been actively studied from the viewpoint of utilization as a carbon resource.

[0005] However, due to its low thermal stability, it is thermally decomposed at temperatures above 180°C, which severely limits its industrial application.

[0006] In addition to carbon dioxide and epoxide, a catalyst is also required to produce polyalkylene carbonate resins. Typical heterogeneous catalysts include zinc dicarboxylate catalysts, such as zinc glutarate catalysts with dicarboxylic acids, and double metal cyanide catalysts consisting of complexes of Co, Zn, Al, etc.

[0007] If such catalysts remain in the resin, the decomposition of polymer chains accelerates during the heat treatment of the resin, further deteriorating the thermal stability of the polyalkylene carbonate resin. Therefore, there is a need to develop various purification techniques to remove catalysts after the completion of polymerization.

[0008] For example, CN103842406B discloses a method for purifying polyalkylene carbonate, which involves producing polyalkylene carbonate in an organic solvent in the presence of a catalyst, removing the organic solvent to form polyalkylene carbonate granules, adding an organic solvent-free aqueous acid solution containing 0.01 to 5 wt% of acid to the granules, performing solid-liquid mixing, heat treatment, and drying. However, the above-mentioned solid-liquid mixing method using the addition of an aqueous acid solution has the problem that, because the polyalkylene carbonate exists in a granular (solid) state in the aqueous acid solution, the efficiency of deactivating the catalyst remaining in the polyalkylene carbonate is low and an excessive amount of acid is required. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] CN103842406B(2016.11.02.) Summary of the Invention [Problem to be solved by the invention]

[0010] An object of the present invention is to provide a polyalkylene carbonate resin composition having excellent thermal stability.

[0011] Another object of the present invention is to provide a method for producing the polyalkylene carbonate resin composition. [Means for solving the problem]

[0012] In order to solve the above problems, the present invention provides a polyalkylene carbonate resin composition and a method for producing the same.

[0013] (1) The present invention provides a polyalkylene carbonate resin composition comprising a polyalkylene carbonate, an organic acid, and one or more additives selected from antioxidants and hydrolysis inhibitors, the organic acid being present in an amount of 0.001 part by weight or more and less than 0.5 parts by weight per 100 parts by weight of the polyalkylene carbonate.

[0014] (2) The present invention provides the polyalkylene carbonate resin composition according to (1) above, which contains 0.05 to 0.1 parts by weight of an organic acid relative to 100 parts by weight of the polyalkylene carbonate.

[0015] (3) The present invention provides the polyalkylene carbonate resin composition according to (1) or (2) above, wherein the organic acid is at least one selected from the group consisting of citric acid, tartaric acid, ascorbic acid, and maleic acid.

[0016] (4) The present invention provides the polyalkylene carbonate resin composition according to any one of (1) to (3) above, which contains 0.01 to 3.00 parts by weight of one or more additives selected from antioxidants and hydrolysis inhibitors, based on 100 parts by weight of the polyalkylene carbonate.

[0017] (5) The present invention is directed to a method for treating an oxidizing agent comprising the steps of: tetrakis[methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate]methane, triethylene glycol-bis-3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionate, thiodiethylene bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 1,2-bis(3,5-di-t-butyl-4-hydroxyhydrocinnamoyl)hydrazine, octadecyl 3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 1,3,5-tris(4-t and (4) a polyalkylene carbonate resin composition, wherein the compound is any one or more selected from the group consisting of 1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 2,4-di-t-pentyl-6-1-(3,5-di-t-pentyl-2-hydroxyphenyl)ethyl)phenyl acrylate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, α-tocopherol, and 2,6-di-t-butyl-p-cresol.

[0018] (6) The present invention provides the polyalkylene carbonate resin composition according to any one of (1) to (5) above, wherein the hydrolysis inhibitor is a carbodiimide compound.

[0019] (7) The present invention provides the polyalkylene carbonate resin composition according to any one of (1) to (6) above, which further contains a metal salt of a fatty acid having 13 to 21 carbon atoms.

[0020] (8) The present invention provides the polyalkylene carbonate resin composition according to any one of (1) to (7) above, further comprising 0.001 to 3,000 parts by weight of a metal salt of a fatty acid having 13 to 21 carbon atoms.

[0021] (9) The present invention provides the polyalkylene carbonate resin composition according to any one of (1) to (8) above, wherein the rate of change in molecular weight defined by the following mathematical formula 1 is 35% or less:

[0022] [Mathematical formula 1] Molecular weight change rate (%) = (|Mw1-Mw2| / Mw1) × 100

[0023] In the above mathematical formula 1, Mw1 is the weight average molecular weight of the polyalkylene carbonate resin composition before heat treatment, measured by gel chromatography, and Mw2 is the weight average molecular weight of the polyalkylene carbonate resin composition after heat treatment at 180°C for 20 minutes, measured by gel chromatography.

[0024] (10) The present invention provides the polyalkylene carbonate resin composition according to any one of (1) to (9), wherein the polyalkylene carbonate contains a repeating unit represented by the following chemical formula 1 and a repeating unit represented by the following chemical formula 2:

[0025] [ka]

[0026] [ka]

[0027] In the above Chemical Formula 1 and Chemical Formula 2, R1 to R8 each independently represent a hydrogen atom, a linear alkyl group having 1 to 20 carbon atoms, a branched alkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or a cycloalkyl group having 3 to 20 carbon atoms; * denotes a linkage site between repeating units; x and y are mole fractions, where x is 0.70 to 1.00, y is 0.00 to 0.30, and x+y is 1.

[0028] (11) The present invention provides the polyalkylene carbonate resin composition according to any one of (1) to (10) above, wherein the polyalkylene carbonate has a glass transition temperature of -10°C to 50°C.

[0029] (12) The present invention provides the polyalkylene carbonate resin composition according to any one of (1) to (11) above, wherein the polyalkylene carbonate is at least one selected from the group consisting of polyethylene carbonate, polypropylene carbonate, polypentene carbonate, polyhexene carbonate, polyoctene carbonate, and polycyclohexene carbonate.

[0030] (13) The present invention provides the polyalkylene carbonate resin composition according to any one of (1) to (12) above, wherein the polyalkylene carbonate has a cyclic carbonate content of 0.5% by weight to 15% by weight.

[0031] (14) The present invention provides a method for producing a polyalkylene carbonate resin composition according to any one of (1) to (13), comprising the steps of: (S1) polymerizing an alkylene oxide compound and carbon dioxide in a solvent in the presence of a catalyst to produce a polymer containing polyalkylene carbonate; (S2) adding an organic acid and one or more additives selected from an antioxidant and a hydrolysis inhibitor to the polymer and stirring the mixture; and (S3) removing the solvent, wherein the organic acid is added in an amount of 0.001 part by weight or more and less than 0.5 part by weight per 100 parts by weight of the polyalkylene carbonate solid content in the polymer.

[0032] (15) The present invention provides the method for producing a polyalkylene carbonate resin composition according to (14) above, wherein a solvent is further added to the polymer before the organic acid is added so that the content of polyalkylene carbonate solids in the polymer is 10% by weight to 40% by weight.

[0033] (16) The present invention provides the method for producing a polyalkylene carbonate resin composition according to (14) or (15) above, wherein the polymerization is carried out in a temperature range of 30°C to 120°C.

[0034] (17) The present invention provides the method for producing the polyalkylene carbonate resin composition according to any one of (14) to (16), wherein in the step (S2), a metal salt of a fatty acid having 13 to 21 carbon atoms is further added to the polymer.

[0035] (18) The present invention provides a method for producing a polyalkylene carbonate resin composition according to any one of (14) to (17) above, wherein the catalyst comprises a double metal cyanide compound and a complexing agent.

[0036] (19) The present invention is directed to a method for producing a cyclopentanol-based cyclopentanol complex, wherein the complexing agent is selected from the group consisting of cyclobutanol, cyclopentanol, cyclohexanol, cycloheptanol, cyclooctanol, 1-methyl cyclopentanol, 2-methyl cyclopentanol, 3-methyl cyclopentanol, 1-ethyl cyclopentanol, 2-ethyl cyclopentanol, 3-ethyl cyclopentanol, 1-propyl cyclopentanol, 2-propyl cyclopentanol, and 3-propyl cyclopentanol. cyclopentanol, 1-butyl cyclopentanol, 2-butyl cyclopentanol, 3-butyl cyclopentanol, 1-isopropyl cyclopentanol, 2-isopropyl cyclopentanol, 3-isopropyl cyclopentanol, 1-(propan-2-yl)cyclopentanol, 2,2-dimethyl cyclopentanol, 2,3-dimethyl cyclopentanol, 3,3-dimethyl cyclopentanol, 1,2-dimethyl cyclopentanol cyclopentanol), 1,3-dimethylcyclopentanol (1,3-dimethyl cyclopentanol, 1-methyl cyclohexanol, 1-ethyl cyclohexanol, 1-propyl cyclohexanol, 1-butyl cyclohexanol cyclohexanol, 2-methyl-1-cyclohexanol, 2-ethyl-1-cyclohexanol, 3-ethyl-1-cyclohexanol, 4-ethyl-1-cyclohexanol, 2-propyl-1-cyclohexanol, 3-propyl-1-cyclohexanol, 4-propyl-1-cyclohexanol, 2-butyl-1-cyclohexanol, 3-butyl-1-cyclohexanol, 4-butyl-1-cyclohexanol 4-butyl-1-cyclohexanol, 2-isopropyl-1-cyclohexanol, 3-isopropyl-1-cyclohexanol, 4-isopropyl-1-cyclohexanol, 2-tert-butyl-1-cyclohexanol, 3-tert-butyl-1-cyclohexanol, 4-tert-butyl-1-cyclohexanol, 2,3-dimethyl-1-cyclohexanol, 2,4-dimethyl-1-cyclohexanoland (18) a method for producing a polyalkylene carbonate resin composition, wherein the alkylene carbonate is at least one selected from the group consisting of 1-methylcycloheptanol, 2-methylcycloheptanol, 3-methylcycloheptanol, and 4-methylcycloheptanol. [Effects of the Invention]

[0037] The polyalkylene carbonate resin composition according to the present invention contains 0.001 part by weight or more and less than 0.5 part by weight of an organic acid per 100 parts by weight of polyalkylene carbonate, and by containing an antioxidant and / or a hydrolysis inhibitor, the thermal decomposition temperature is increased and thermal stability is improved. [Brief explanation of the drawings]

[0038] The following drawings attached to this specification are intended to illustrate specific embodiments of the present invention and, together with the above-described content of the invention, serve to further understand the technical concept of the present invention. Therefore, the present invention should not be interpreted as being limited only to the matters shown in these drawings. [Figure 1] 1 is a graph showing the results of mass change analysis using a thermogravimetric analyzer for polyethylene carbonate resin compositions produced in Examples and Comparative Examples. DETAILED DESCRIPTION OF THE INVENTION

[0039] The present invention will now be described in more detail so that the present invention may be more easily understood.

[0040] The terms and words used in the description of the present invention and the claims should not be interpreted in a limited way to their ordinary or dictionary meanings, but should be interpreted in a way that is consistent with the technical idea of ​​the present invention, based on the principle that the inventors can appropriately define the concepts of terms in order to best describe their invention.

[0041] (Definition of terms) As used herein, the term "alkyl group" may mean a monovalent aliphatic saturated hydrocarbon group.

[0042] As used herein, the term "aryl group" refers to a cyclic aromatic hydrocarbon, and may include either a monocyclic aromatic hydrocarbon formed by one ring, or a polycyclic aromatic hydrocarbon formed by combining two or more rings.

[0043] As used herein, the term "alkenyl group" may mean a monovalent aliphatic unsaturated hydrocarbon containing one or more double bonds.

[0044] As used herein, the term "cycloalkyl group" may refer to either a cyclic saturated hydrocarbon or a cyclic unsaturated hydrocarbon containing one or more unsaturated bonds.

[0045] (Measurement method) In this specification, molecular weight characteristics were analyzed by gel permeation chromatography (GPC) using polystyrene as a standard. Specifically, GPC (Waters 1515 isocratic HPLC pump, Waters 2414 refractive index detector, Waters) was used under the following conditions. Column: Agilent PLgel MIXED-B, 2 columns (7.5 mm x 300, 10 μm) Solvent: Chloroform Flow rate: 0.7ml / min Column temperature: 40℃ Sample: 4.0 mg / 1.0 ml chloroform Sample injection volume: 20 μl Standard material: polystyrene

[0046] In this specification, the mass change analysis was measured using a TGA (thermogravimetric analyzer), specifically, using a TGA (TGA2, Mettler Toledo) under the following conditions. 1) 1st step: Heat from 30°C to 150°C (10°C / min) 2) 2-step: Isothermal at 150°C for 5 minutes 3) 3 steps: Temperature decrease from 150°C to 30°C (10°C / min) 4) 4 steps: Isothermal at 30°C for 5 minutes 5) 5 steps: Heat from 30°C to 400°C (10°C / min)

[0047] (Polyalkylene carbonate resin composition) The present invention provides a polyalkylene carbonate resin composition that is inhibited from thermal decomposition and has improved thermal stability.

[0048] A polyalkylene carbonate resin composition according to one embodiment of the present invention comprises a polyalkylene carbonate, an organic acid, and one or more additives selected from antioxidants and hydrolysis inhibitors, and is characterized in that the organic acid is contained in an amount of 0.001 part by weight or more and less than 0.5 parts by weight per 100 parts by weight of the polyalkylene carbonate.

[0049] Polyalkylene carbonate resins are produced using carbon dioxide as a raw material and have attracted attention as biodegradable resins. However, their low thermal stability means they undergo thermal decomposition at temperatures above 180°C, significantly limiting their industrial application. Furthermore, producing polyalkylene carbonate resins requires not only carbon dioxide and epoxide but also a catalyst. If the catalyst remains in the resin, it accelerates the decomposition of polymer chains during the resin's heat treatment, further deteriorating the thermal stability of the polyalkylene carbonate resin. Therefore, there is a need to develop various purification technologies to remove the catalyst after polymerization is complete.

[0050] However, in the polyalkylene carbonate resin composition according to one embodiment of the present invention, after polymerization of polyalkylene carbonate, a specific amount of an organic acid and at least one additive selected from an antioxidant and a hydrolysis inhibitor is directly added to the polymer to inactivate the residual catalyst without an additional process such as extraction or precipitation, thereby suppressing thermal decomposition and exhibiting excellent thermal stability.

[0051] The polyalkylene carbonate resin composition according to the present invention will be described in more detail below, dividing it into each of the constituent components contained therein.

[0052] (Polyalkylene carbonate) In the present invention, the polyalkylene carbonate is a polymer produced by polymerizing an alkylene oxide compound and carbon dioxide, and may include a repeating unit represented by the following Chemical Formula 1 and a repeating unit represented by the following Chemical Formula 2.

[0053] [ka]

[0054] [ka]

[0055] In the above Chemical Formula 1 and Chemical Formula 2, R1 to R8 are each independently hydrogen, a linear alkyl group having 1 to 20 carbon atoms, a branched alkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or a cycloalkyl group having 3 to 20 carbon atoms; * represents a linking site between repeating units; x and y are mole fractions, where x is 0.70 to 1.00, y is 0.00 to 0.30, and x+y is 1.

[0056] Furthermore, x may be 0.80 to 1.00, and y may be 0.00 to 0.20, and preferably, x may be 0.90 to 1.00, and y may be 0.00 to 0.10. When the above ranges are satisfied, the carbon dioxide fixation ratio is high, which is effective in reducing greenhouse gases and is advantageous in terms of biodegradability. Furthermore, when the polyalkylene carbonate according to the present invention is produced into a film, the film exhibits low oxygen permeability, which is effective in providing excellent barrier properties.

[0057] The polyalkylene carbonate may be any one or more selected from the group consisting of polyethylene carbonate, polypropylene carbonate, polypentene carbonate, polyhexene carbonate, polyoctene carbonate, and polycyclohexene carbonate. Furthermore, in Chemical Formula 1, R1 to R8 are each independently hydrogen, a linear alkyl group having 1 to 20 carbon atoms, a branched alkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or a cycloalkyl group having 3 to 20 carbon atoms, and may be selected as an appropriate functional group in consideration of the physical properties of the resin to be ultimately obtained.

[0058] The repeating unit represented by Chemical Formula 1 may be a repeating unit represented by Chemical Formula 3 below.

[0059] [ka]

[0060] In the above chemical formula 1, R1 to R4 are each independently hydrogen or a linear alkyl group having 1 to 10 carbon atoms, and x and * are as defined in the above chemical formula 1.

[0061] More specifically, the repeating unit represented by Chemical Formula 1 may be represented by Chemical Formula 4 or Chemical Formula 5 below.

[0062] [ka]

[0063] [ka]

[0064] In the chemical formulas 4 and 5, x and * are as defined in the chemical formula 1.

[0065] The repeating unit represented by Chemical Formula 2 may be a repeating unit represented by Chemical Formula 6 below.

[0066] [ka]

[0067] In the above chemical formula 6, R5 to R8 are each independently a hydrogen atom or a linear alkyl group having 1 to 10 carbon atoms, and y and * are as defined in the above chemical formula 2.

[0068] More specifically, the repeating unit represented by Chemical Formula 2 may be represented by Chemical Formula 7 or Chemical Formula 8 below.

[0069] [ka]

[0070] [ka]

[0071] In the chemical formulas 7 and 8, y and * are as defined in the chemical formula 2.

[0072] The polyalkylene carbonate of the present invention has a glass transition temperature (Tg) of −10° C. to 50° C., 0° C. to 50° C., or 10° C. to 50° C. When the above range is satisfied, the polyalkylene carbonate can have excellent processability at room temperature.

[0073] As yet another example, when R1 to R8 in Chemical Formula 1 and Chemical Formula 2 are each independently hydrogen, the polyalkylene carbonate may have a glass transition temperature (Tg) of 0°C to 20°C.

[0074] As yet another example, when R1 to R8 in Chemical Formula 1 and Chemical Formula 2 are each independently a linear alkyl group having 1 to 20 carbon atoms, a branched alkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or a cycloalkyl group having 3 to 20 carbon atoms, the polyalkylene carbonate may have a glass transition temperature (Tg) of 30°C to 50°C or 35°C to 50°C.

[0075] In addition, the content of the cyclic carbonate may be 0.5 wt% to 15.0 wt%, 0.5 wt% to 10.0 wt%, or 0.5 wt% to 5.0 wt% based on the total weight of the polyalkylene carbonate of the present invention. When the content is within the above range, the problem of a decrease in glass transition temperature due to the cyclic carbonate acting as a softener can be minimized, and excellent mechanical properties can be achieved.

[0076] The content of the cyclic carbonate is 1 Measurement can be performed using a H-NMR spectrometer (500 MHz Spectrometer, Jeol) by dissolving 10 mg of a polyalkylene carbonate resin sample in a chloroform-d6 solvent. 1From the results of measurement using a H-NMR spectrometer, it was confirmed that a peak appeared at around 4.5 ppm, which is the peak of cyclic carbonate. Using the peak area of ​​carbonate and the peak area of ​​ether, the content of cyclic carbonate can be calculated using the following mathematical formula 2.

[0077]

number

[0078] In the above mathematical formula 2, the A, B, C, N, and CO2 contents may be defined as follows: A = cyclic carbonate peak area, B = carbonate peak area, C = ether peak area, N = [molar mass of alkylene oxide / (44 + molar mass of alkylene oxide)], CO2 content = (molar fraction of carbonate unit × 44) / [(molar fraction of carbonate unit × 44) + (molar mass of alkylene oxide × 100)]

[0079] (organic acid) In one embodiment of the present invention, the organic acid serves to inactivate the catalyst, and may be contained in the polyalkylene carbonate resin composition in an amount of 0.001 parts by weight or more but less than 0.5 parts by weight per 100 parts by weight of the polyalkylene carbonate.

[0080] Specifically, the polyalkylene carbonate resin composition may contain 0.05 to 0.1 parts by weight of an organic acid.

[0081] When the organic acid is contained within the above range, the catalyst can be effectively inactivated without causing the problem of accelerating the thermal decomposition of the polyalkylene carbonate, and therefore the thermal stability of the composition can be effectively improved.

[0082] The organic acid may be at least one selected from the group consisting of citric acid, tartaric acid, ascorbic acid, and maleic acid.

[0083] (antioxidant) In one embodiment of the present invention, the antioxidant serves to remove radicals, and may be contained in the polyalkylene carbonate resin composition in an amount of 0.01 to 3.00 parts by weight relative to 100 parts by weight of the polyalkylene carbonate.

[0084] Specifically, when the polyalkylene carbonate resin composition contains an antioxidant, the antioxidant may be contained in an amount of 0.05 to 1.50 parts by weight.

[0085] When the antioxidant is contained within the above range, it is possible to effectively prevent a decrease in molecular weight due to thermal decomposition of the polycarbonate, and also to suppress a decrease in transparency.

[0086] The antioxidant may be any antioxidant commonly known in the art, and examples thereof include tetrakis[methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate]methane, triethylene glycol-bis-3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionate, thiodiethylene bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 1,2-bis(3,5-di-t-butyl-4-hydroxyhydrocinnamoyl)hydrazine, octadecyl 3-(3,5-di-t butyl-4-hydroxyphenyl)propionate, 1,3,5-tris(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 2,4-di-t-pentyl-6-1-(3,5-di-t-pentyl-2-hydroxyphenyl)ethyl)phenyl acrylate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, α-tocopherol, and 2,6-di-t-butyl-p-cresol.

[0087] (hydrolysis inhibitor) In one embodiment of the present invention, the hydrolysis inhibitor serves to prevent the polycarbonate from being hydrolyzed by reacting with moisture, and may be included in the polyalkylene carbonate resin composition in an amount of 0.01 to 3.00 parts by weight based on 100 parts by weight of the polyalkylene carbonate.

[0088] Specifically, when the polyalkylene carbonate resin composition contains a hydrolysis inhibitor, the hydrolysis inhibitor may be contained in an amount of 0.05 to 1.50 parts by weight.

[0089] When the hydrolysis inhibitor is contained within the above range, hydrolysis due to moisture is suppressed, and a decrease in the molecular weight of the polycarbonate can be effectively prevented, and yellowing can also be suppressed.

[0090] The hydrolysis inhibitor is not particularly limited as long as it is commonly known in the art, and may be, for example, a carbodiimide compound.

[0091] In one embodiment of the present invention, the carbodiimide compound is a general term for compounds containing an -N=C=N- unit in the molecule, and specifically, the carbodiimide compound may contain 1 to 1000, 1 to 100, or 1 to 10 -N=CN- units.

[0092] As yet another example, the carbodiimide compound may be bis(2,6-diisopropylphenyl)carbodiimide or poly[1,3,5-triisopropylphenylene-2,4-carbodiamide].

[0093] (Polyalkylene carbonate resin composition) The polyalkylene carbonate resin composition according to one embodiment of the present invention may have a molecular weight change rate defined by the following mathematical formula 1 of 35% or less.

[0094] [Mathematical formula 1] Molecular weight change rate (%) = (|Mw1-Mw2| / Mw1) × 100

[0095] In the above mathematical formula 1, Mw1 is the weight average molecular weight of the polyalkylene carbonate resin composition before heat treatment, as measured by gel chromatography, and Mw2 is the weight average molecular weight of the polyalkylene carbonate resin composition after heat treatment at 180°C for 20 minutes, as measured by gel chromatography.

[0096] Furthermore, the polyalkylene carbonate resin composition according to one embodiment of the present invention may further contain a metal salt of a fatty acid having 13 to 21 carbon atoms, as necessary. As another example, the polyalkylene carbonate resin composition may further contain 0.001 to 3,000 parts by weight of a metal salt of a fatty acid having 13 to 21 carbon atoms.

[0097] When the polyalkylene carbonate resin composition contains the fatty acid metal salt, yellowing and a decrease in molecular weight can be more effectively prevented.

[0098] Furthermore, when the polyalkylene carbonate resin composition according to one embodiment of the present invention further contains a metal salt of a fatty acid having 13 to 21 carbon atoms, the weight ratio of the organic acid to the metal salt of the fatty acid may be 1:0.01 to 5 or 1:0.5 to 2. When this ratio is satisfied, yellowing of the polyalkylene carbonate resin composition is improved and a decrease in molecular weight is prevented.

[0099] The metal salt of a fatty acid having 13 to 21 carbon atoms may be a calcium salt of the fatty acid, more specifically, calcium stearate, magnesium stearate, or a combination thereof.

[0100] Meanwhile, a polyalkylene carbonate resin composition according to one embodiment of the present invention is prepared by the below-described preparation method in which an organic acid, an antioxidant, a hydrolysis inhibitor, and / or a fatty acid metal salt are added and then removed without any step of removing them, and therefore, the content of the organic acid, the antioxidant, the hydrolysis inhibitor, and / or the fatty acid metal salt in the polyalkylene carbonate resin composition may be the same as the amount added during preparation.

[0101] As another example, in the present invention, the contents of the organic acid, antioxidant, hydrolysis inhibitor, and / or fatty acid metal salt in the polyalkylene carbonate resin composition can also be determined by a component quantitative analysis method generally known in the art, and for example, a quantitative analysis device such as UPLC / MS / MS, HPLC / RI, or UPLC-QTOF / MS can be used.

[0102] In addition, the content of the organic acid, antioxidant, hydrolysis inhibitor, and / or fatty acid metal salt is such that there is no difference between the amount added during production and the content analyzed using a quantitative analyzer, or is within the margin of error (±10%).

[0103] (Method for producing polyalkylene carbonate resin composition) The present invention provides a method for producing the polyalkylene carbonate resin composition.

[0104] A method for producing a polyalkylene carbonate resin composition according to one embodiment of the present invention includes the steps of: (S1) polymerizing an alkylene oxide compound and carbon dioxide in a solvent in the presence of a catalyst to produce a polymer containing polyalkylene carbonate; (S2) adding an organic acid and one or more additives selected from antioxidants and hydrolysis inhibitors to the polymer and stirring; and (S3) removing the solvent, wherein the organic acid is added in an amount of 0.001 to less than 0.5 parts by weight per 100 parts by weight of the polyalkylene carbonate solids in the polymer. Because the above-described production method according to one embodiment of the present invention does not include an additional step for catalyst removal, such as extraction or precipitation, after polymerization, the polymer contains the catalyst.

[0105] Each step will be explained in more detail below. (S1) Step The step (S1) is a step of forming a polyalkylene carbonate and producing a polymer containing the polyalkylene carbonate, and can be carried out by polymerizing an alkylene oxide compound and carbon dioxide in a solvent in the presence of a catalyst.

[0106] The catalyst includes a double metal cyanide compound and a complexing agent, and any double metal cyanide compound and complexing agent commonly used in the art can be used without limitation.

[0107] For example, the double metal cyanide compound may be derived from a metal cyanide complex salt and a metal salt, and the metal cyanide complex salt may be water-soluble. Specifically, the metal cyanide complex salt may be represented by the following Chemical Formula 10:

[0108] [Chemical formula 10] Y a M'(CN) b

[0109] In Formula 10, M' is at least one selected from the group consisting of Fe(II), Fe(III), Co(II), Co(III), Cr(II), Cr(III), Mn(II), Mn(III), Ir(III), Ni(II), Rh(III), Ru(II), V(V), and V(IV), and preferably at least one selected from the group consisting of Co(II), Co(III), Fe(II), Fe(III), Cr(III), Ir(III), and Ni(II). Y is an alkali metal ion or alkaline earth metal ion. a is an integer from 1 to 4, and b is an integer from 4 to 6, and the values ​​of a and b are selected so that the metal cyanide complex salt is electrically neutral.

[0110] As another example, the metal cyanide complex salt may be potassium hexacyanocobaltate(III), potassium hexacyanoferrate(II), potassium hexacyanoferrate(III), calcium hexacyanocobaltate(III), or lithium hexacyanoiridate(III), and preferably potassium hexacyanocobaltate(III).

[0111] The metal salt may be water-soluble. Specifically, the metal salt may be represented by the following formula 11:

[0112] [Chemical formula 11] M(X) n

[0113] In Formula 11, M represents a transition metal, preferably at least one selected from the group consisting of Zn(II), Fe(II), Ni(II), Mn(II), Co(II), Sn(II), Pb(II), Fe(III), Mo(IV), Mo(VI), Al(III), V(V), V(IV), Sr(II), W(IV), W(VI), Cu(II), and Cr(III), more preferably at least one selected from the group consisting of Zn(II), Fe(II), Co(II), and Ni(II). X represents an anion selected from the group consisting of halide, hydroxide, sulfate, carbonate, cyanate, oxalate, thiocyanate, isocyanate, isothiocyanate, carboxylate, and nitrate. The value of n is a number that satisfies the valence state of M.

[0114] As another example, the metal salt may be zinc chloride (II), zinc chloride (III), zinc bromide, zinc iodide, zinc acetate, zinc acetylacetonate, zinc benzoate, zinc nitrate, iron (II) sulfate, iron (II) bromide, cobalt (II) chloride, cobalt (II) thiocyanate, nickel (II) formate, nickel (II) nitrate, and mixtures thereof, and preferably zinc chloride (II), zinc chloride (III), zinc bromide, or zinc iodide.

[0115] The catalyst according to the present invention may be represented by the following chemical formula 12:

[0116] [Chemical formula 12] M 2 p [M 1 (CN)6] q dM 2 (X) r ·eL·fH2O

[0117] In the above chemical formula 12, M 1 and M 2are each independently a transition metal, X is an anion, L is cyclobutanol, cyclopentanol, cyclohexanol, cycloheptanol, or cyclooctanol, and p, q, d, r, e, and f are each independently an integer of 1 to 6.

[0118] More specifically, the catalyst according to the present invention may be represented by the following chemical formula 13:

[0119] [Chemical formula 13] Zn3[Co(CN)6]2·gZnCl2·hL·iH2O

[0120] In the above Chemical Formula 13, L is cyclobutanol, cyclopentanol, cyclohexanol, cycloheptanol, or cyclooctanol, and g, h, and i are each independently an integer of 1 to 6.

[0121] The complexing agent may be any complexing agent commonly used in the art, and may be, for example, at least one selected from the group consisting of ethanol, isopropanol, normal butanol, isobutanol, sec-butanol, and tert-butanol.

[0122] As yet another example, the complexing agent may be a compound represented by the following Chemical Formula 9:

[0123] [ka]

[0124] In the above chemical formula 9, R 9a and R 9b are each independently a single bond or an alkylene group having 1 to 5 carbon atoms, and R 9a and R 9b at least one of which is an alkylene group having 1 to 5 carbon atoms; R 9c and R 9dare each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, n is an integer of 0 to 2.

[0125] Specifically, in the above-mentioned Chemical Formula 9, R 9a and R 9b are each independently a single bond or an alkylene group having 1 to 3 carbon atoms, and R 9a and R 9b At least one of R is an alkylene group having 1 to 3 carbon atoms, 9c and R 9d are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and n may be an integer of 0 to 2.

[0126] As another example, in the above-mentioned Chemical Formula 9, R 9s and R 9b are each independently a single bond or an alkylene group having 1 to 3 carbon atoms, and R 9a and R 9b At least one of R is an alkylene group having 1 to 3 carbon atoms, 9c is a hydrogen atom, and n may be 0.

[0127] As yet another example, the complexing agent may be a cycloalkyl alcohol having 3 to 12 carbon atoms, specifically a cycloalkyl alcohol having 4 to 10 carbon atoms or 5 to 7 carbon atoms.

[0128] More specifically, the complexing agent may be cyclobutanol, cyclopentanol, cyclohexanol, cycloheptanol, cyclooctanol, 1-methyl cyclopentanol, 2-methyl cyclopentanol, 3-methyl cyclopentanol, 1-ethyl cyclopentanol, 2-ethyl cyclopentanol, 3-ethyl cyclopentanol, 1-propyl cyclopentanol, 2-propyl cyclopentanol, 3-propyl cyclopentan ... cyclopentanol, 1-butyl cyclopentanol, 2-butyl cyclopentanol, 3-butyl cyclopentanol, 1-isopropyl cyclopentanol, 2-isopropyl cyclopentanol, 3-isopropyl cyclopentanol, 1-(propan-2-yl)cyclopentanol, 2,2-dimethyl cyclopentanol, 2,3-dimethyl cyclopentanol, 3,3-dimethyl cyclopentanol, 1,2-dimethyl cyclopentanol cyclopentanol), 1,3-dimethylcyclopentanol (1,3-dimethyl cyclopentanol, 1-methyl cyclohexanol, 1-ethyl cyclohexanol, 1-propyl cyclohexanol, 1-butyl cyclohexanol cyclohexanol, 2-methyl-1-cyclohexanol, 2-ethyl-1-cyclohexanol, 3-ethyl-1-cyclohexanol, 4-ethyl-1-cyclohexanol, 2-propyl-1-cyclohexanol, 3-propyl-1-cyclohexanol, 4-propyl-1-cyclohexanol, 2-butyl-1-cyclohexanol, 3-butyl-1-cyclohexanol, 4-butyl-1-cyclohexanol 4-butyl-1-cyclohexanol, 2-isopropyl-1-cyclohexanol, 3-isopropyl-1-cyclohexanol, 4-isopropyl-1-cyclohexanol, 2-tert-butyl-1-cyclohexanol, 3-tert-butyl-1-cyclohexanol, 4-tert-butyl-1-cyclohexanol, 2,3-dimethyl-1-cyclohexanol, 2,4-dimethyl-1-cyclohexanolThe complexing agent may be any one or more selected from the group consisting of 4-dimethyl-1-cyclohexanol, 3,4-dimethyl-1-cyclohexanol, 1-methyl cycloheptanol, 2-methyl cycloheptanol, 3-methyl cycloheptanol, and 4-methyl cycloheptanol. Specifically, the complexing agent may be any one or more selected from the group consisting of cyclobutanol, cyclopentanol, cyclohexanol, cycloheptanol, and cyclooctanol.

[0129] As yet another example, the complexing agent may be any one or more selected from the group consisting of cyclobutanol, cyclopentanol, cyclohexanol, cycloheptanol, and cyclooctanol.

[0130] Meanwhile, when the catalyst contains a compound represented by Chemical Formula 9 as a complexing agent, the crystalline structure of the catalyst can be variously configured, such as cubic, amorphous, and monoclinic, by using a cycloalkane alcohol having a bulky structure as a complexing agent. As a result, the reaction rate of the epoxide compound and carbon dioxide can be appropriately controlled, increasing the proportion of repeating units containing carbon dioxide in the produced polyalkylene carbonate and reducing the content of cyclic carbonate by-products, thereby producing a polyalkylene carbonate with excellent thermal stability and processability.

[0131] Furthermore, the catalyst may further contain a secondary complexing agent, if necessary, and the secondary complexing agent may be a compound having a hydroxy group, an amine group, an ester group, or an ether group at its terminal.

[0132] The secondary complexing agent can improve the activity of the catalyst, and examples thereof include polyacrylamide, poly(acrylamide-co-acrylic acid), polyacrylic acid, poly(acrylic acid-co-maleic acid), polyacrylonitrile, polyalkyl acrylate, polyalkyl methacrylate, polyvinyl methyl ether, polyvinyl ethyl ether, polyvinyl acetate, polyvinyl alcohol, poly-N-vinylpyrrolidone, poly(N-vinylpyrrolidone-co-acrylic acid), polyvinyl methyl ketone, poly(4-vinylphenol), poly(acrylic acid-co-styrene), oxazoline polymer, polyalkyleneimine, maleic acid, maleic anhydride copolymer, hydroxyethyl cellulose, polyacetal, glycidyl ether, glycoside, carboxylic acid ester of polyhydric alcohol, gallic acid, ester, and amide.

[0133] The secondary complexing agent may be a compound prepared by ring-opening polymerization of a cyclic ether compound, an epoxy polymer, or an oxetane polymer, and may be, for example, at least one selected from the group consisting of polyether, polyester, polycarbonate, polyalkylene glycol, polyalkylene glycol sorbitan ester, and polyalkylene glycol glycidyl ether.

[0134] The polymerization is not particularly limited, but is preferably carried out by solution polymerization, which allows appropriate control of reaction heat and facilitates control of the weight average molecular weight or viscosity of the polyalkylene carbonate to be obtained.

[0135] The catalyst and alkylene oxide compound may be used in a weight ratio of 1:100 to 1:8000, 1:300 to 1:6000, or 1:1000 to 1:4000. Within the above ranges, high catalytic activity can be exhibited, by-products can be minimized, and back-biting of polyalkylene carbonate produced by heating can be minimized.

[0136] The polymerization of the alkylene oxide compound and carbon dioxide may be carried out within a temperature range of 30° C. to 120° C., 40° C. to 110° C., or 50° C. to 100° C. When the above-mentioned range is satisfied, the polymerization time of the alkylene oxide compound and carbon dioxide can be controlled to within 24 hours, thereby improving production productivity.

[0137] The polymerization of the alkylene oxide compound and carbon dioxide may be carried out within a pressure range of 5 bar to 50 bar, 10 bar to 40 bar, or 15 bar to 30 bar. When the above range is satisfied, the proportion of repeating units containing carbon dioxide in the produced polyalkylene carbonate is high, and the content of cyclic carbonate by-products is reduced.

[0138] The alkylene oxide compound may be any one or more compounds selected from the group consisting of alkylene oxides having 2 to 20 carbon atoms, which may or may not be substituted with a halogen or an alkyl group having 1 to 5 carbon atoms; cycloalkylene oxides having 4 to 20 carbon atoms, which may or may not be substituted with a halogen or an alkyl group having 1 to 5 carbon atoms; and styrene oxides having 8 to 20 carbon atoms, which may or may not be substituted with a halogen or an alkyl group having 1 to 5 carbon atoms. Examples of the alkylene oxide compound include ethylene oxide, propylene oxide, butene oxide, pentene oxide, hexene oxide, octene oxide, decene oxide, dodecene oxide, tetradecene oxide, hexadecene oxide, octadecene oxide, butadiene monoxide, 1,2-epoxy-7-octene, epifluorohydrin, epichlorohydrin, epibromohydrin, isopropyl glycol, and the like. Any one or more compounds selected from the group consisting of glycidyl ether, butyl glycidyl ether, t-butyl glycidyl ether, 2-ethylhexyl glycidyl ether, allyl glycidyl ether, cyclopentene oxide, cyclohexene oxide, cyclooctene oxide, cyclododecene oxide, alpha-pinene oxide, 2,3-epoxynorbornene, limonene oxide, dieldrin, 2,3-epoxypropylbenzene, styrene oxide, phenylpropylene oxide, stilbene oxide, chlorostilbene oxide, dichlorostilbene oxide, 1,2-epoxy-3-phenoxypropane, benzyloxymethyloxirane, glycidyl methylphenyl ether, chlorophenyl-2,3-epoxypropyl ether, epoxypropyl methoxyphenyl ether, biphenyl glycidyl ether, and glycidyl naphthyl ether may be used.

[0139] In addition, when the alkylene oxide compound and carbon dioxide are polymerized by solution polymerization, the alkylene oxide compound may be mixed with a solvent, such as methylene chloride, ethylene dichloride, trichloroethane, tetrachloroethane, chloroform, acetonitrile, propionitrile, dimethylformamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, nitromethane, 1,3-dioxalane (dioxolane), 1,4-dioxane, hexane, toluene, tetrahydrofuran, methyl ethyl ketone, methylamine ketone, methyl isobutyl ketone, acetone, cyclohexanone, trichloroethylene, methyl acetate, vinyl acetate, ethyl acetate, propyl acetate, butyrolactone, caprolactone, nitropropane, benzene, styrene, xylene, and methyl propasol.

[0140] The solvent and alkylene oxide compound may be used in a weight ratio of 1:0.1 to 1:100, 1:1 to 1:100, or 1:1 to 1:10. Within this range, the solvent can function appropriately as a reaction medium, improving the productivity of the polyalkylene carbonate resin and minimizing by-products generated during the production process.

[0141] (S2) Step The step (S2) is a step of adding an organic acid and one or more additives selected from an antioxidant and a hydrolysis inhibitor to the polymer containing the polyalkylene carbonate produced above, and stirring the mixture.

[0142] The organic acid may be added in an amount of 0.001 part by weight or more and less than 0.5 part by weight per 100 parts by weight of the polyalkylene carbonate solid content in the polymer, and specific organic acids are as described above.

[0143] Furthermore, one or more additives selected from the antioxidants and hydrolysis inhibitors may be added in an amount of 0.01 to 3.00 parts by weight per 100 parts by weight of the polyalkylene carbonate solid content in the polymer, and specific antioxidants and hydrolysis inhibitors are as described above.

[0144] As another example, in step (S2), a fatty acid metal salt having 13 to 21 carbon atoms may be further added to the polymer. In this case, the fatty acid metal salt may be added in an amount of 0.001 to 3,000 parts by weight per 100 parts by weight of the polyalkylene carbonate solid content in the polymer, and specific examples of the fatty acid metal salt are as described above.

[0145] The stirring is a means for mixing the organic acid so that it is uniformly distributed in the polymer, and as long as this purpose can be achieved, the stirring can be carried out under conditions that are not particularly limited.

[0146] Meanwhile, before adding the organic acid, a step of adding a solvent to the polymer may be further performed so that the polyalkylene carbonate solid content in the polymer is 10 wt% to 40 wt%. In this case, the viscosity of the polymer may be reduced and the organic acid may be more uniformly mixed in the polymer. In this case, the solvent may be the same as the solvent used in step (S1) or may be one or more selected from the above-mentioned solvents.

[0147] In addition, the method for producing a polymer according to an embodiment of the present invention does not require additional steps such as extraction or precipitation to remove catalyst components after polymerization, which simplifies the process, reduces the cost of the additional steps, and improves economic efficiency and productivity.

[0148] (S3) Step The step (S3) is a solvent removal step for removing the solvent to prepare a polyalkylene carbonate resin composition.

[0149] Here, the removal of the solvent is not particularly limited as long as the purpose of removing the solvent can be achieved, and may be carried out by a means commonly used in the art, for example, by applying heat at a temperature of 30°C to 150°C for 30 minutes to 10 hours. [Example]

[0150] The present invention will be described in more detail below with reference to examples. However, the following examples are for illustrative purposes only and are not intended to limit the scope of the present invention.

[0151] (Manufacturing example) In a first 500 ml beaker, 11.45 g of zinc chloride, 30 ml of distilled water, and 39 g of cyclohexanol were mixed to prepare the first mixed solution. In a second 250 ml beaker, 4 g of potassium hexacyanocobaltate was dissolved in 100 ml of distilled water to prepare the second mixed solution. In a third 100 ml beaker, 5 g of polypropylene glycol (Mw = 3,000) and 23 g of cyclohexanol were dissolved in 2 ml of distilled water to prepare the third mixed solution. Using a mechanical stirrer, the second mixed solution was added dropwise to the first mixed solution over one hour at 25°C, and then the third mixed solution was added all at once and reacted for one hour. The mixed product was then separated by high-speed centrifugation, and the separated precipitate was washed twice with a mixture of 70 ml of distilled water and 70 ml of cyclohexanol. After further washing with 140 ml of cyclohexanol, the washed precipitate was dried in a vacuum oven at 80° C. for 12 hours to finally obtain 6.2 g of double metal cyanide catalyst.

[0152] Example 1 A high-pressure reactor was charged with 10 mg of the double metal cyanide catalyst prepared in Preparation Example, 20 g of ethylene oxide, and 10 g of dioxolane solvent. Carbon dioxide was then introduced into the reactor and pressurized to 30 bar. The polymerization reaction was carried out at 70°C for 24 hours. After completion of the reaction, unreacted carbon dioxide was removed to produce a polymer containing polyethylene carbonate. The polymer was then diluted with dioxolane solvent to a polyethylene carbonate solids content of 20 wt%. Then, 0.1 parts by weight of citric acid and 0.5 parts by weight of an antioxidant (SONGNOX® 1010, SONGWON Co.) were added per 100 parts by weight of polyethylene carbonate solids, stirred, poured onto a tray, and dried in a vacuum oven at 40°C for 6 hours to produce a polyethylene carbonate resin composition. The residual catalyst components in the composition were Co = 80 ppm and Zn = 165 ppm.

[0153] Example 2 A polyethylene carbonate resin composition was produced in the same manner as in Example 1, except that 0.5 parts by weight of SONGNOX® 1035 (SONGWON Co., Ltd.) was added as an antioxidant per 100 parts by weight of the polyethylene carbonate solids. The catalyst components remaining in the composition were also at the same level as in Example 1.

[0154] Example 3 A polyethylene carbonate resin composition was prepared in the same manner as in Example 1, except that 0.5 parts by weight of SONGNOX® 2450 (SONGWON Co., Ltd.) was added as an antioxidant per 100 parts by weight of the polyethylene carbonate solids. The catalyst components remaining in the composition were also at the same level as in Example 1.

[0155] Example 4 A polyethylene carbonate resin composition was produced in the same manner as in Example 1, except that 0.5 parts by weight of SONGNOX® 1024 (SONGWON Co., Ltd.) was added as an antioxidant per 100 parts by weight of the polyethylene carbonate solids. The catalyst components remaining in the composition were also at the same level as in Example 1.

[0156] Example 5 A polyethylene carbonate resin composition was produced in the same manner as in Example 1, except that 0.5 parts by weight of a hydrolysis inhibitor (ZIKA-AHP213, ZICO Corporation) was added per 100 parts by weight of the polyethylene carbonate solids instead of the antioxidant in Example 1. The amount of catalyst component remaining in the composition was also at the same level as in Example 1.

[0157] Example 6 A polyethylene carbonate resin composition was produced in the same manner as in Example 3, except that 0.5 parts by weight of a hydrolysis inhibitor (ZIKA-AHP213, ZICO Corporation) was further added per 100 parts by weight of the polyethylene carbonate solids. The catalyst components remaining in the composition were also at the same level as in Example 3.

[0158] Example 7 A polyethylene carbonate resin composition was produced in the same manner as in Example 1, except that 0.05 parts by weight of citric acid was added per 100 parts by weight of the polyethylene carbonate solids, and 0.05 parts by weight of calcium stearate (citric acid: fatty acid metal salt = 1:1 weight ratio) per 100 parts by weight of the polyethylene carbonate solids. The catalyst components remaining in the composition were also at the same level as in Example 1.

[0159] Example 8 A polyethylene carbonate resin composition was produced in the same manner as in Example 1, except that 0.3 parts by weight of citric acid was added per 100 parts by weight of the polyalkylene carbonate solids content. The catalyst component remaining in the composition was also at the same level as in Example 1.

[0160] Example 9 A polyethylene carbonate resin composition was produced in the same manner as in Example 1, except that 0.05 parts by weight of tartaric acid was added per 100 parts by weight of the polyethylene carbonate solids content instead of citric acid. The catalyst component remaining in the composition was also at the same level as in Example 1.

[0161] Example 10 A polyethylene carbonate resin composition was produced in the same manner as in Example 9, except that 0.2 parts by weight of maleic acid per 100 parts by weight of the polyethylene carbonate solids content was added instead of citric acid in Example 9. In this case, the catalyst component remaining in the composition was at the same level as in Example 9.

[0162] (Comparative Example 1) A polyethylene carbonate resin composition was produced in the same manner as in Example 1, except that no antioxidant was added. At this time, the catalyst component remaining in the composition was at the same level as in Example 1.

[0163] (Comparative Example 2) A polyethylene carbonate resin composition was produced in the same manner as in Example 1, except that 0.5 parts by weight of citric acid was added per 100 parts by weight of the polyethylene carbonate solids content in Example 1. In this case, the catalyst component remaining in the composition was at the same level as in Example 1.

[0164] (Comparative Example 3) A polyethylene carbonate resin composition was produced in the same manner as in Example 1, except that 0.0005 parts by weight of citric acid was added per 100 parts by weight of the polyethylene carbonate solids content. The catalyst component remaining in the composition was also at the same level as in Example 1.

[0165] (Experimental example) The molecular weight characteristics and thermal stability of the polyalkylene carbonate compositions prepared in the examples and comparative examples were compared and analyzed, and the results are shown in Table 1 below and Figure 1.

[0166] (1) Molecular weight characteristics Molecular weight properties were analyzed by gel permeation chromatography (GPC) using polystyrene as a standard. Column: Agilent PLgel MIXED-B, 2 columns (7.5 mm x 300, 10 μm) Solvent: Chloroform Flow rate: 0.7ml / min Column temperature: 40℃ Sample: 4.0 mg / 1.0 ml chloroform Sample injection volume: 20 μl Standard material: polystyrene

[0167] In addition, each molecular weight characteristic was measured before and after the heat treatment of the polyalkylene carbonate composition, and the rate of change in molecular weight was also confirmed using the following mathematical formula 1.

[0168] [Mathematical formula 1] Molecular weight change rate (%) = (|Mw1-Mw2| / Mw1) × 100

[0169] In the above mathematical formula 1, Mw1 is the weight average molecular weight of the polyalkylene carbonate resin composition before heat treatment, measured by gel chromatography, and Mw2 is the weight average molecular weight of the polyalkylene carbonate resin composition after heat treatment at 180°C for 20 minutes, measured by gel chromatography.

[0170] (2) Thermal stability The thermal stability was evaluated by mass change analysis using a TGA (thermogravimetric analyzer), and the temperature at which a mass loss of 5% by weight occurred was recorded as the thermal decomposition temperature.

[0171] Specifically, the mass change analysis was performed using a thermogravimetric analyzer (TGA2, Mettler Toledo) according to the following steps. 1) 1st step: Heat from 30°C to 150°C (10°C / min) 2) 2-step: Isothermal at 150°C for 5 minutes 3) 3 steps: Temperature decrease from 150°C to 30°C (10°C / min) 4) 4 steps: Isothermal at 30°C for 5 minutes 5) 5 steps: Heat from 30°C to 400°C (10°C / min)

[0172] [Table 1]

[0173] As shown in Table 1 and Figure 1, it was confirmed that the polyethylene carbonate resin compositions of Examples 1 to 10 had a molecular weight change rate of 35% or less and a higher thermal decomposition temperature compared to the comparative examples. Specifically, the polyethylene carbonate resin compositions of Examples 1 to 10 had a molecular weight change rate of 26% to 66% compared to the polyethylene carbonate resin composition of Comparative Example 1, which did not contain an additive (antioxidant), and the change in molecular weight due to heat treatment was significantly reduced. From this, it was confirmed that the polyalkylene carbonate resin composition according to the present invention, by containing both an organic acid and an additive, has the effect of suppressing thermal decomposition and significantly improving thermal stability.

[0174] Furthermore, Comparative Example 2, which contained an organic acid but exceeded the upper limit of the range of suitable amounts proposed in the present invention, showed a molecular weight change of 45%, indicating a reduced effect in inhibiting thermal decomposition of the polymer chain, while Comparative Example 3, which contained an amount below the lower limit of the range of suitable amounts, showed a molecular weight change of 40%, a thermal decomposition temperature of 246°C, and a minimal effect in inhibiting thermal decomposition. From these results, it can be confirmed that when an organic acid is contained but outside the range proposed in the present invention, the thermal decomposition is accelerated or there is no effect in deactivating the catalyst.

Claims

1. a polyalkylene carbonate; Organic acids and and one or more additives selected from antioxidants and hydrolysis inhibitors; A polyalkylene carbonate resin composition comprising an organic acid in an amount of 0.001 part by weight or more and less than 0.5 part by weight based on 100 parts by weight of the polyalkylene carbonate.

2. 2. The polyalkylene carbonate resin composition according to claim 1, comprising 0.05 to 0.1 parts by weight of an organic acid per 100 parts by weight of the polyalkylene carbonate.

3. 2. The polyalkylene carbonate resin composition according to claim 1, wherein the organic acid is at least one selected from the group consisting of citric acid, tartaric acid, ascorbic acid, and maleic acid.

4. 2. The polyalkylene carbonate resin composition according to claim 1, comprising 0.01 to 3.00 parts by weight of one or more additives selected from antioxidants and hydrolysis inhibitors, based on 100 parts by weight of the polyalkylene carbonate.

5. The antioxidant is selected from the group consisting of tetrakis[methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate]methane, triethylene glycol-bis-3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionate, thiodiethylene bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 1,2-bis(3,5-di-t-butyl-4-hydroxyhydrocinnamoyl)hydrazine, octadecyl 3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 1,3,5-tris( 2. The polyalkylene carbonate resin composition according to claim 1, wherein the alkylene carbonate is at least one selected from the group consisting of 4-t-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 2,4-di-t-pentyl-6-1-(3,5-di-t-pentyl-2-hydroxyphenyl)ethyl)phenyl acrylate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, α-tocopherol, and 2,6-di-t-butyl-p-cresol.

6. 2. The polyalkylene carbonate resin composition according to claim 1, wherein the hydrolysis inhibitor is a carbodiimide compound.

7. The polyalkylene carbonate resin composition according to claim 1, further comprising a metal salt of a fatty acid having 13 to 21 carbon atoms.

8. 2. The polyalkylene carbonate resin composition according to claim 1, further comprising 0.001 to 3,000 parts by weight of a metal salt of a fatty acid having 13 to 21 carbon atoms.

9. The polyalkylene carbonate resin composition according to claim 1, wherein the molecular weight change rate defined by the following mathematical formula 1 is 35% or less. [Mathematical formula 1] Molecular weight change rate (%) = (| Mw 1 -Mw 2 | / Mw 1 ) x 100 (In the above mathematical formula 1, Mw 1 is the weight average molecular weight of the polyalkylene carbonate resin composition before heat treatment measured by gel chromatography, and Mw 2 is the weight average molecular weight of the polyalkylene carbonate resin composition measured by gel chromatography after heat treatment at 180°C for 20 minutes.

10. The polyalkylene carbonate resin composition according to claim 1, wherein the polyalkylene carbonate comprises a repeating unit represented by the following chemical formula 1 and a repeating unit represented by the following chemical formula 2: 【Chemistry 12】 【Chemistry 13】 (In the above Chemical Formula 1 and Chemical Formula 2, R 1 ~R 8 are each independently a hydrogen atom, a linear alkyl group having 1 to 20 carbon atoms, a branched alkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or a cycloalkyl group having 3 to 20 carbon atoms; * means a linking site between repeating units, x and y are mole fractions, x is 0.70 to 1.00, y is 0.00 to 0.30, and x+y is 1.

11. The polyalkylene carbonate resin composition according to claim 1, wherein the polyalkylene carbonate has a glass transition temperature of -10°C to 50°C.

12. 2. The polyalkylene carbonate resin composition according to claim 1, wherein the polyalkylene carbonate is at least one selected from the group consisting of polyethylene carbonate, polypropylene carbonate, polypentene carbonate, polyhexene carbonate, polyoctene carbonate, and polycyclohexene carbonate.

13. The polyalkylene carbonate resin composition according to claim 1, wherein the polyalkylene carbonate has a cyclic carbonate content of 0.5% by weight to 15% by weight.

14. A step (S1) of polymerizing an alkylene oxide compound and carbon dioxide in a solvent in the presence of a catalyst to produce a polymer containing polyalkylene carbonate; a step (S2) of adding an organic acid and one or more additives selected from an antioxidant and a hydrolysis inhibitor to the polymer and stirring the mixture; and (S3) removing the solvent, The method for producing a polyalkylene carbonate resin composition, wherein the organic acid is added in an amount of 0.001 part by weight or more and less than 0.5 part by weight per 100 parts by weight of the polyalkylene carbonate solid content in the polymer.

15. The method for producing a polyalkylene carbonate resin composition according to claim 14, wherein a solvent is further added to the polymer before the organic acid is added so that the polyalkylene carbonate solid content in the polymer is 10% by weight to 40% by weight.

16. The method for producing a polyalkylene carbonate resin composition according to claim 14, wherein the polymerization is carried out at a temperature range of 30°C to 120°C.

17. The method for producing a polyalkylene carbonate resin composition according to claim 14, wherein in the step (S2), a metal salt of a fatty acid having 13 to 21 carbon atoms is further added to the polymer.

18. 15. The method for producing a polyalkylene carbonate resin composition according to claim 14, wherein the catalyst comprises a double metal cyanide compound and a complexing agent.

19. The complexing agent may be cyclobutanol, cyclopentanol, cyclohexanol, cycloheptanol, cyclooctanol, 1-methylcyclopentanol, 2-methylcyclopentanol, 3-methylcyclopentanol, 1-ethylcyclopentanol, 2-ethylcyclopentanol, 3-ethyl ...1-ethylcyclopentanol, 2-ethylcyclopentanol, 3-ethylcyclopentanol, 1-ethylcyclopentanol, 2-ethylcyclopentanol, 3-ethylcyclopentanol, 1-ethylcyclopentanol, 2-ethylcyclopentanol, 3-ethylcyclopentanol, 1-ethylcyclopentanol, 2-ethylcyclopentanol, 3-ethylcyclopent cyclopentanol), 1-propyl cyclopentanol, 2-propyl cyclopentanol, 3-propyl cyclopentanol, 1-butyl cyclopentanol, 2-butyl cyclopentanol, 3-butyl cyclopentanol, 1-isopropyl cyclopentanol, 2-isopropyl cyclopentanol cyclopentanol), 3-isopropyl cyclopentanol, 1-propan-2-yl cyclopentanol, 2,2-dimethyl cyclopentanol, 2,3-dimethyl cyclopentanol, 3,3-dimethyl cyclopentanol, 1,2-dimethyl cyclopentanol, 1,3-dimethyl cyclopentanol3-dimethyl cyclopentanol), 1-methyl cyclohexanol, 1-ethyl cyclohexanol, 1-propyl cyclohexanol, 1-butyl cyclohexanol cyclohexanol), 2-methyl-1-cyclohexanol, 2-ethyl-1-cyclohexanol, 3-ethyl-1-cyclohexanol, 4-ethyl-1-cyclohexanol, 2-propyl-1-cyclohexanol propyl-1-cyclohexanol), 3-propyl-1-cyclohexanol, 4-propyl-1-cyclohexanol, 2-butyl-1-cyclohexanol, 3-butyl-1-cyclohexanol, 4-butyl-1-cyclohexanol 4-butyl-1-cyclohexanol, 2-isopropyl-1-cyclohexanol, 3-isopropyl-1-cyclohexanol, 4-isopropyl-1-cyclohexanol, 2-tert-butyl-1-cyclohexanol -tert-butyl-1-cyclohexanol), 3-tert-butyl-1-cyclohexanol, 4-tert-butyl-1-cyclohexanol, 2,3-dimethyl-1-cyclohexanol, 2,4-dimethyl-1-cyclohexanolThe method for producing a polyalkylene carbonate resin composition according to claim 18, wherein the alkylene carbonate is at least one selected from the group consisting of 1,4-dimethyl-1-cyclohexanol, 3,4-dimethyl-1-cyclohexanol, 1-methylcycloheptanol, 2-methylcycloheptanol, 3-methylcycloheptanol, and 4-methylcycloheptanol.

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