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 containing a polyalkylene carbonate and an organic acid, in which the organic acid is contained 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, and a method for producing the same.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0015651, filed February 6, 2023, and Korean Patent Application No. 10-2023-0082943 and No. 10-2023-0082944, filed June 27, 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 various research projects are being conducted, including the regulation of carbon dioxide emissions and fixation.

[0004] Recently, polyalkylene carbonate resins obtained by polymerizing carbon dioxide and epoxides have been attracting 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 is therefore being actively studied from the perspective of their use 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] Furthermore, in order to produce polyalkylene carbonate resins, not only carbon dioxide and epoxide but also a catalyst is necessarily required, and typical heterogeneous catalysts used include zinc dicarboxylate catalysts such as zinc glutarate catalysts bound to dicarboxylic acids, and double metal cyanide catalysts consisting of complexes of Co, Zn, Al, etc.

[0007] If such catalysts remain in the resin, they accelerate the decomposition of polymer chains 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, forming polyalkylene carbonate granules, adding an acid aqueous solution containing 0.01 to 5 wt% of acid in the absence of an organic solvent, performing solid-liquid mixing, heat treatment, and drying. However, this solid-liquid mixing method using the addition of an acid aqueous solution has the problem that the polyalkylene carbonate exists in a granular (solid) state in the acid aqueous solution, which results in low efficiency in deactivating the catalyst remaining in the polyalkylene carbonate and requires an excessive amount of acid. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] CN103842406B (November 2, 2016) 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 100 parts by weight of a polyalkylene carbonate and 0.001 part by weight or more and less than 0.5 part by weight of an organic acid.

[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 the organic acid.

[0015] (3) The present invention provides a polyalkylene carbonate resin composition according to (1) or (2), further comprising a metal element derived from a double metal cyanide compound, wherein the weight ratio of the organic acid to the metal element (organic acid / metal element) is 0.05 to 23.00.

[0016] (4) The present invention provides the polyalkylene carbonate resin composition according to any one of (1) to (3) above, wherein the weight ratio of the organic acid to the metal element (organic acid / metal element) is 0.05 to 14.00.

[0017] (5) The present invention provides the polyalkylene carbonate resin composition according to any one of (1) to (4) above, wherein the organic acid is at least one selected from the group consisting of citric acid, tartaric acid, ascorbic acid, and maleic acid.

[0018] (6) The present invention provides a polyalkylene carbonate resin composition according to any one of (3) to (5), wherein the double metal cyanide compound contains a component derived from a metal cyanide complex and a component derived from a metal salt, the metal cyanide complex being represented by the following chemical formula 1, and the metal salt being represented by the following chemical formula 2: [Chemical formula 1] Y a M'(CN) b In the above Chemical Formula 1, 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); Y is an alkali metal ion or an alkaline earth metal ion; a is an integer from 1 to 4, and b is an integer from 4 to 6, the values ​​of a and b being selected so that the metal cyanide complex is electrically neutral; [Chemical formula 2] M(X) n In the above Chemical Formula 2, M is 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); X is any one anion selected from the group consisting of halide, hydroxide, sulfate, carbonate, cyanate, oxalate, thiocyanate, isocyanate, isothiocyanate, carboxylate, and nitrate; n is the number that satisfies the M valence state.

[0019] (7) The present invention provides the polyalkylene carbonate resin composition according to (6) above, wherein the metal cyanide complex is potassium hexacyanocobaltate(III), potassium hexacyanoferrate(II), potassium hexacyanoferrate(III), calcium hexacyanocobaltate(III), or lithium hexacyanoiridate(III).

[0020] (8) The present invention provides the polyalkylene carbonate resin composition according to (6) above, wherein the metal salt is at least one selected from the group consisting of 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, and nickel (II) nitrate.

[0021] (9) The present invention provides a polyalkylene carbonate resin composition according to any one of the above items (1) to (8), wherein the mass change rate defined by the following mathematical formula 1 is 10% or less: [Mathematical formula 1] Mass change rate (%) = (|W1-W2| / W1) x 100 In the above mathematical formula 1, W1 is the mass of the polyalkylene carbonate resin composition at time 0 of a 60-minute isothermal step at 200°C in a mass change analysis using a thermogravimetric analyzer, and W2 is the mass of the polyalkylene carbonate resin composition at time 60 of a 60-minute isothermal step at 200°C.

[0022] (10) The present invention provides a polyalkylene carbonate resin composition according to any one of the above items (1) to (9), wherein the rate of change in molecular weight defined by the following mathematical formula 2 is 55% or less: [Mathematical formula 2] Molecular weight change rate (%) = (|M W1 -M W2 | / M W1 ) x 100 In the above mathematical formula 2, M W1 is the weight average molecular weight of the polyalkylene carbonate resin composition before heat treatment measured by gel chromatography, and M W2 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.

[0023] (11) The present invention provides a polyalkylene carbonate resin composition according to any one of the above (1) to (10), wherein the polyalkylene carbonate contains a repeating unit represented by the following chemical formula 3 and a repeating unit represented by the following chemical formula 4: [ka] [ka] In the above Chemical Formula 3 and Chemical Formula 4, 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; * indicates 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.

[0024] (12) The present invention provides the polyalkylene carbonate resin composition according to any one of the above (1) to (11), wherein the polyalkylene carbonate has a glass transition temperature of -10°C to 50°C.

[0025] (13) The present invention provides the polyalkylene carbonate resin composition according to any one of (1) to (12) 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.

[0026] (14) The present invention provides the polyalkylene carbonate resin composition according to any one of the above (1) to (13), wherein the polyalkylene carbonate has a cyclic carbonate content of 0.5% by weight to 15% by weight.

[0027] (15) The present invention provides a method for producing a polyalkylene carbonate resin composition according to any one of (1) to (14), comprising the steps 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; adding an organic acid to the polymer and stirring the mixture; and 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 solid content of polyalkylene carbonate in the polymer.

[0028] (16) The present invention provides a method for producing a polyalkylene carbonate resin composition according to the above (15), wherein the catalyst contains a double metal cyanide compound and a complexing agent.

[0029] (17) The present invention provides the method for producing a polyalkylene carbonate resin composition according to either one of (15) or (16), further comprising adding a solvent to the polymer before adding the organic acid so that the content of the polyalkylene carbonate solids in the polymer is 10% by weight to 40% by weight.

[0030] (18) The present invention provides the method for producing a polyalkylene carbonate resin composition according to any one of the above (15) to (17), wherein the polymerization is carried out in a temperature range of 50°C to 120°C.

[0031] (19) The present invention is directed to any one of the above (15) to (18), wherein the complexing agent is 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 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 cyclopentanol), 1,2-dimethyl 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 present invention provides a method for producing a polyalkylene carbonate resin composition, wherein the polyalkylene carbonate is at least one selected from the group consisting of 1-methylcycloheptanol, 2-methylcycloheptanol, 3-methylcycloheptanol, and 4-methylcycloheptanol. [Effects of the Invention]

[0032] 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 therefore has the effect of improving thermal stabilization by inactivating the activity of the catalyst remaining in the resin composition with the organic acid.

[0033] Furthermore, the polyalkylene carbonate resin composition according to the present invention contains an organic acid, and in this case, the organic acid is present in a specific weight ratio relative to the residual catalyst component, which has the effect of further inactivating the activity of the catalyst remaining in the resin composition, thereby further improving thermal stabilization. [Brief explanation of the drawings]

[0034] The following drawings attached to this specification 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, and therefore the present invention should not be interpreted as being limited solely to the matters depicted in such drawings.

[0035] [Figure 1] 1 is a graph showing the results of mass change analysis of the polyethylene carbonate resin compositions produced in Examples 1 to 7 using a thermogravimetric analyzer. [Figure 2]1 is a graph showing the results of mass change analysis of the polyethylene carbonate resin compositions produced in Example 1 and Comparative Examples 1 to 5 using a thermogravimetric analyzer. DETAILED DESCRIPTION OF THE INVENTION

[0036] The present invention will now be described in more detail to aid in understanding the present invention.

[0037] The terms and words used in the description of the present invention and the claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted as meanings and concepts that are consistent with the technical idea of ​​the present invention, based on the principle that inventors can appropriately define the concepts of terms in order to best describe their inventions.

[0038] (Definition of terms) As used herein, the term "alkyl group" may mean a monovalent aliphatic saturated hydrocarbon group.

[0039] As used herein, the term "aryl group" may refer to a cyclic aromatic hydrocarbon, and may include both monocyclic aromatic hydrocarbons formed by one ring and polycyclic aromatic hydrocarbons formed by linking two or more rings.

[0040] As used herein, the term "alkenyl group" may mean a monovalent aliphatic unsaturated hydrocarbon containing one or more double bonds.

[0041] As used herein, the term "cycloalkyl group" may mean any cyclic saturated hydrocarbon group or any cyclic unsaturated hydrocarbon group containing one or more unsaturated bonds.

[0042] (Measurement method) In this specification, molecular weight characteristics are analyzed by gel permeation chromatography (GPC) using polystyrene as a standard substance. Specifically, the molecular weight characteristics were measured using GPC (Waters 1515 isocratic HPLC pump, Waters 2414 refractive index detector, manufactured by Waters) under the following conditions:

[0043] 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

[0044] 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.

[0045] 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: Heat from 150°C to 200°C (10°C / min) 4) 4-step: Isothermal at 200°C for 60 minutes

[0046] (Polyalkylene carbonate resin composition) The present invention provides a polyalkylene carbonate resin composition that is inhibited from thermal decomposition and has improved thermal stability.

[0047] A polyalkylene carbonate resin composition according to one embodiment of the present invention is characterized by comprising 100 parts by weight of polyalkylene carbonate; and 0.001 part by weight or more and less than 0.5 part by weight of an organic acid.

[0048] Furthermore, a polyalkylene carbonate resin composition according to one embodiment of the present invention comprises a polyalkylene carbonate; an organic acid; and a metal element derived from a double metal cyanide compound, and is characterized in that the weight ratio of the organic acid to the metal element (organic acid / metal element) is 0.05 to 23.00.

[0049] Specifically, in the polyalkylene carbonate resin composition according to one embodiment of the present invention, the weight ratio of organic acid to metal element (organic acid / metal element) can be 0.05 to 14.00, 0.05 to 5.00, or 0.05 to 1.00.

[0050] Polyalkylene carbonate resins are produced using carbon dioxide as a raw material and have attracted much attention as biodegradable resins, but 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 such a catalyst remains in the resin, it accelerates the decomposition of polymer chains during the heat treatment process of the resin, 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.

[0051] However, in the polyalkylene carbonate resin composition according to one embodiment of the present invention, a specific amount of organic acid is directly added to the polymer after polymerization of polyalkylene carbonate, thereby containing a constant amount of organic acid. This inactivates the remaining catalyst without an additional process such as extraction or precipitation, thereby suppressing thermal decomposition and providing excellent thermal stability.

[0052] 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.

[0053] (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 3 and a repeating unit represented by the following Chemical Formula 4:

[0054] [ka]

[0055] [ka]

[0056] In the above Chemical Formula 3 and Chemical Formula 4, 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 represent mole fractions, x is 0.70 to 1.00, y is 0.00 to 0.30, and x+y is 1.

[0057] 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 these ranges are satisfied, the carbon dioxide fixation rate 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.

[0058] The polyalkylene carbonate may be one or more selected from the group consisting of polyethylene carbonate, polypropylene carbonate, polypentene carbonate, polyhexene carbonate, polyoctene carbonate, and polycyclohexene carbonate. 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.

[0059] In addition, the repeating unit represented by Chemical Formula 3 may be represented by Chemical Formula 5 below.

[0060] [ka]

[0061] In the above chemical formula 5, 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 3.

[0062] More specifically, the repeating unit represented by Formula 3 may be represented by Formula 6 or 7 below.

[0063] [ka]

[0064] [ka]

[0065] In the above Chemical Formulae 6 and 7, x and * are as defined in the above Chemical Formula 1.

[0066] In addition, the repeating unit represented by Chemical Formula 4 may be represented by Chemical Formula 8 below.

[0067] [ka]

[0068] In the above chemical formula 8, R5 to R8 are each independently hydrogen or a linear alkyl group having 1 to 10 carbon atoms, and y and * are as defined in the above chemical formula 4.

[0069] More specifically, the repeating unit represented by Formula 4 may be represented by Formula 9 or 10 below.

[0070] [ka]

[0071] [ka]

[0072] In the above Chemical Formulae 9 and 10, y and * are as defined in the above Chemical Formula 2.

[0073] 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.

[0074] As yet another example, the polyalkylene carbonate may have a glass transition temperature (Tg) of 0°C to 20°C when R1 to R8 in Chemical Formula 3 and Chemical Formula 4 are each independently hydrogen.

[0075] As yet another example, the polyalkylene carbonate may have a glass transition temperature (Tg) of 30°C to 50°C or 35°C to 50°C when R1 to R8 in Chemical Formula 3 and Chemical Formula 4 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.

[0076] 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.

[0077] The content of the cyclic carbonate is 1 Measurement can be performed using a H-NMR spectrometer (500 MHz Spectrometer, manufactured by Jeol) by dissolving 10 mg of a polyalkylene carbonate resin sample in a chloroform-d6 solvent. 1 From 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 carbonate peak area and the ether peak area, the cyclic carbonate content can be calculated using the following mathematical formula 3.

[0078]

number

[0079] In the above mathematical formula 3, the contents of A, B, C, N and CO2 can be defined as follows:

[0080] 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)]

[0081] (organic acid) In one embodiment of the present invention, the organic acid serves to inactivate the catalyst and may be included 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.

[0082] Specifically, the polyalkylene carbonate resin composition may contain 0.05 to 0.1 parts by weight of an organic acid.

[0083] For example, when the organic acid is contained within the above range, the problem of accelerating the thermal decomposition of the polyalkylene carbonate does not occur, and the catalyst can be effectively deactivated, thereby effectively improving the thermal stability of the composition.

[0084] Meanwhile, the polyalkylene carbonate resin composition according to one embodiment of the present invention is prepared by the below-described preparation method without a step of adding and then removing an organic acid, and thus the content of the organic acid in the polyalkylene carbonate resin composition may be the same as the amount added during preparation.

[0085] In another example, the content of the organic acid in the polyalkylene carbonate resin composition of the present invention can be determined by a component quantitative analysis method generally known in the art. For example, a quantitative analysis device such as UPLC / MS / MS, HPLC / RI, or UPLC-QTOF / MS can be used.

[0086] Furthermore, the content of the organic acid is such that there is no difference between the amount added during production and the amount analyzed using a quantitative analyzer, or the difference is within the margin of error (±10%).

[0087] The organic acid may be at least one selected from the group consisting of citric acid, tartaric acid, ascorbic acid, and maleic acid.

[0088] (metallic components) In one embodiment of the present invention, the metal component may be a residue of a catalyst used in producing a polyalkylene carbonate resin composition, i.e., a residual catalyst component.

[0089] Specifically, the metal component is a metal component derived from a double metal cyanide compound, and the double metal cyanide compound includes a component derived from a metal cyanide complex and a component derived from a metal salt.

[0090] More specifically, the double metal cyanide compound may be derived from a metal cyanide complex and a metal salt, and the metal cyanide complex may be water-soluble and may be represented by the following Chemical Formula 1:

[0091] [Chemical formula 1] Y a M'(CN) b

[0092] In Formula 1, 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). Specifically, M' can be at least one selected from the group consisting of Co(II), Co(III), Fe(II), Fe(III), Cr(III), Ir(III), and Ni(II). More specifically, M' can be Co(II) or Co(III). Y is an alkali metal ion or an alkaline earth metal ion. a is an integer from 1 to 4, and b is an integer from 4 to 6. The values ​​of a and b are selected so that the metal cyanide complex is electrically neutral.

[0093] As another example, the metal cyanide complex may be potassium hexacyanocobaltate(III), potassium hexacyanoferrate(II), potassium hexacyanoferrate(III), calcium hexacyanocobaltate(III), or lithium hexacyanoiridate(III), and preferably potassium hexacyanocobaltate(III).

[0094] The metal salt may be water-soluble and may be represented by the following Chemical Formula 2:

[0095] [Chemical formula 2] M(X) n

[0096] In Formula 2, 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), specifically 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.

[0097] 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, or a mixture thereof, and preferably zinc chloride (II), zinc chloride (III), zinc bromide, or zinc iodide.

[0098] (Polyalkylene carbonate resin composition) The polyalkylene carbonate resin composition according to one embodiment of the present invention may have a mass change rate defined by the following Equation 1 of 10% or less.

[0099] [Mathematical formula 1] Mass change rate (%) = (|W1-W2| / W1) x 100

[0100] In Equation 1, W1 is the mass of the polyalkylene carbonate resin composition at time 0 of a 60-minute isothermal step at 200°C in a mass change analysis using a thermogravimetric analyzer, and W2 is the mass of the polyalkylene carbonate resin composition at time 60 of a 60-minute isothermal step at 200°C.

[0101] As another example, the polyalkylene carbonate resin composition may have a molecular weight change rate defined by the following mathematical formula 2 of 55% or less.

[0102] [Mathematical formula 2] Molecular weight change rate (%) = (|M W1 -M W2 | / M W1 ) x 100

[0103] In the above mathematical formula 2, M W1 is the weight average molecular weight of the polyalkylene carbonate resin composition before heat treatment measured by gel chromatography, and M W2 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.

[0104] (Method for producing polyalkylene carbonate resin composition) The present invention provides a method for producing the polyalkylene carbonate resin composition.

[0105] 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 to the polymer and stirring, and (S3) removing the solvent, wherein the organic acid is added in an amount of 0.001 to 0.5 parts by weight per 100 parts by weight of the polyalkylene carbonate solids in the polymer. The method according to one embodiment of the present invention does not include an additional step for removing the catalyst, such as extraction or precipitation, after polymerization, and therefore the polymer contains the catalyst.

[0106] Each step will be explained in more detail below. (S1) Step The step (S1) is a step of forming a polyalkylene carbonate and preparing 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.

[0107] The catalyst includes a double metal cyanide compound and a complexing agent, and the double metal cyanide compound and the complexing agent can be any conventional double metal cyanide compound and complexing agent known in the art without any restrictions.

[0108] For example, the double metal cyanide compound may be derived from a metal cyanide complex and a metal salt, and the metal cyanide complex may be water-soluble.

[0109] Specific examples of the double metal cyanide compounds are as described above.

[0110] The catalyst according to the present invention may be represented by the following formula 11:

[0111] [Chemical formula 11] M 2 p [M 1 (CN)6] q ·dM 2 (X) r ·eL·fH2O

[0112] In the above chemical formula 11, M 1 and M 2 are 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.

[0113] More specifically, the catalyst according to the present invention may be represented by the following formula 12:

[0114] [Chemical formula 12] Zn3[Co(CN)6]2·gZnCl2·hL·iH2O

[0115] In the above Chemical Formula 12, L is cyclobutanol, cyclopentanol, cyclohexanol, cycloheptanol, or cyclooctanol, and g, h, and i are each independently an integer of 1 to 6.

[0116] 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.

[0117] As yet another example, the complexing agent may be a compound represented by the following Formula 13:

[0118] [ka]

[0119] In the above Chemical Formula 13, 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 the groups is an alkylene group having 1 to 5 carbon atoms; R 9c and R 9d are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, n is an integer of 0 to 2.

[0120] Specifically, in the above-mentioned chemical formula 13, 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 9dare each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and n can be an integer of 0 to 2.

[0121] As another example, in the formula 13, 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 can be 0.

[0122] As yet another example, the complexing agent may be a cycloalkyl alcohol having 3 to 12 carbon atoms, and specifically, a cycloalkyl alcohol having 4 to 10 carbon atoms or 5 to 7 carbon atoms.

[0123] 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 ...ethyl cyclopentanol, 2-ethyl 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-cyclohexanolThe complexing agent may be 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 one or more selected from the group consisting of cyclobutanol, cyclopentanol, cyclohexanol, cycloheptanol, and cyclooctanol.

[0124] As yet another example, the complexing agent may be at least one selected from the group consisting of cyclobutanol, cyclopentanol, cyclohexanol, cycloheptanol, and cyclooctanol.

[0125] Meanwhile, when the catalyst contains a compound represented by Chemical Formula 13 as a complexing agent, the use of a cycloalkane alcohol having a bulky structure as a complexing agent may result in a variety of crystalline structures of the catalyst, such as cubic, amorphous, and monoclinic. This allows for appropriate control of the reaction rate of the epoxide compound and carbon dioxide, increasing the ratio of repeating units containing carbon dioxide in the produced polyalkylene carbonate, reducing the content of cyclic carbonate by-products, and producing a polyalkylene carbonate that exhibits better thermal stability and processability.

[0126] Furthermore, the catalyst may further contain an auxiliary complexing agent, if necessary, and the auxiliary complexing agent may be a compound having a hydroxy group, an amine group, an ester group, or an ether group at its terminal.

[0127] The auxiliary 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.

[0128] In addition, the auxiliary complexing agent may be a compound prepared by ring-opening polymerization of a cyclic ether compound, an epoxy polymer, or an oxetane polymer, and for example, may be at least one selected from the group consisting of polyether, polyester, polycarbonate, polyalkylene glycol, polyalkylene glycol sorbitan ester, and polyalkylene glycol glycidyl ether.

[0129] 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.

[0130] The catalyst and alkylene oxide compound can 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.

[0131] The polymerization of the alkylene oxide compound and carbon dioxide can 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.

[0132] 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.

[0133] 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, substituted or unsubstituted with a halogen or an alkyl group having 1 to 5 carbon atoms; cycloalkylene oxides having 4 to 20 carbon atoms, substituted or unsubstituted with a halogen or an alkyl group having 1 to 5 carbon atoms; and styrene oxides having 8 to 20 carbon atoms, substituted or unsubstituted 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 glycidyl ether, butyl ... Any one or more compounds selected from the group consisting of methyl 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.

[0134] In addition, when the polymerization of the alkylene oxide compound and carbon dioxide is carried out by solution polymerization, the alkylene oxide compound may be mixed with a solvent, and the solvent may be at least one selected from the group consisting of 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.

[0135] The solvent and alkylene oxide compound can 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.

[0136] (S2) Step The step (S2) is a step of adding an organic acid to the polymer containing the polyalkylene carbonate prepared above and stirring the mixture.

[0137] The organic acid can be added in an amount of 0.001 part by weight or more but less than 0.5 part by weight per 100 parts by weight of the solid content of the polyalkylene carbonate in the polymer, and specific organic acids are as described above.

[0138] The stirring is a means for mixing the organic acid so that it is uniformly distributed in the polymer, and can be carried out under conditions that are not particularly limited as long as such a purpose can be achieved.

[0139] Alternatively, before adding the organic acid, a step of adding a solvent to the polymer may be performed so that the solid content of the polyalkylene carbonate in the polymer is 10 wt% to 40 wt%, which may reduce the viscosity of the polymer and allow the organic acid to be more uniformly mixed in the polymer. Here, 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.

[0140] In addition, the production method according to one 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.

[0141] (S3) Step The step (S3) is a solvent removal step for producing a polyalkylene carbonate resin composition by removing the solvent.

[0142] Here, the solvent removal can be carried out by any means commonly used in the art, without particular limitation, as long as the solvent removal objective can be achieved. For example, the solvent removal can be carried out by applying heat at a temperature of 30°C to 150°C for 30 minutes to 10 hours. [Example]

[0143] 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.

[0144] Manufacturing example In a first 500ml beaker, 11.45g of zinc chloride, 30ml of distilled water, and 39g of cyclohexanol were mixed to prepare a first mixed solution. In a second 250ml beaker, 4g of potassium hexacyanocobaltate was dissolved in 100ml of distilled water to prepare a second mixed solution. In a third 100ml beaker, 5g of polypropylene glycol (Mw = 3,000) and 23g of cyclohexanol were dissolved in 2ml of distilled water to prepare a third mixed solution. Using a mechanical stirrer, the second mixed solution was added dropwise to the first mixed solution, followed by the third mixed solution, and the mixture was reacted for 1 hour at 25°C. The mixture was then separated using a high-speed centrifuge, and the separated precipitate was washed twice with a mixture of 70ml of distilled water and 70ml 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.

[0145] Example 1 A high-pressure reactor was charged with 10 mg of the double metal cyanide catalyst prepared in the 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 polyalkylene carbonate. The polymer was then diluted with dioxolane solvent to a polyalkylene carbonate solids content of 20 wt%. 0.02 parts by weight of citric acid was added per 100 parts by weight of polyalkylene carbonate solids. After stirring, the mixture was 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 = 66 ppm and Zn = 150 ppm.

[0146] The contents of residual Co and Zn were measured by ICP analysis under the following conditions.

[0147] 0.1 g of the composition was dispensed into a Teflon vessel, weighed, and 2 ml of nitric acid and 1 ml of sulfuric acid were added, followed by sealing with a lid. The composition was then dissolved using a Multiwave 7000 (manufactured by Anton Parr) at 220°C and 140 bar for 60 minutes and at 280°C and 130 bar for 30 minutes. After cooling to room temperature, the residue was removed using a 0.45 μm PTFE filter and diluted with tertiary ultrapure water to prepare an analytical sample.

[0148] ICP analysis was carried out using Thermo Scientific iCAP PRO (manufactured by Thermo Scientific) under the following conditions.

[0149] RF Power: 1,200W Nebulizer gas flow: 0.7 L / min Auxiliary gas flow: 0.5 L / min Cool gas flow: 12L / min Pump speed: 50 rpm Radial viewing height: 10.0 mm Internal Standard:Sc

[0150] Example 2 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 solid content of the polyalkylene carbonate. The catalyst components remaining in the composition were also at the same level as in Example 1.

[0151] Example 3 A polyethylene carbonate resin composition was produced in the same manner as in Example 1, except that 0.1 parts by weight of citric acid was added per 100 parts by weight of the solid content of the polyalkylene carbonate. The catalyst components remaining in the composition were also at the same level as in Example 1.

[0152] Example 4 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 solid content of the polyalkylene carbonate. The catalyst components remaining in the composition were also at the same level as in Example 1.

[0153] Example 5 A polyethylene carbonate resin composition was produced in the same manner as in Example 1, except that 0.01 parts by weight of tartaric acid was added per 100 parts by weight of the solid content of the polyalkylene carbonate instead of citric acid. The catalyst components remaining in the composition were also at the same level as in Example 1.

[0154] Example 6 A polyethylene carbonate resin composition was produced in the same manner as in Example 1, except that 0.002 parts by weight of maleic acid was added per 100 parts by weight of the solid content of the polyalkylene carbonate instead of citric acid. The catalyst components remaining in the composition were also at the same level as in Example 1.

[0155] Example 7 A polyethylene carbonate resin composition was produced in the same manner as in Example 1, except that 0.004 parts by weight of ascorbic acid was added per 100 parts by weight of the solid content of the polyalkylene carbonate instead of citric acid. The catalyst components remaining in the composition were also at the same level as in Example 1.

[0156] Comparative Example 1 A polyethylene carbonate resin composition was produced in the same manner as in Example 1, except that citric acid was not added. The catalyst components remaining in the composition were also at the same level as in Example 1.

[0157] Comparative Example 2 A polyethylene carbonate resin composition was produced in the same manner as in Example 1, except that 0.76 parts by weight of citric acid was added per 100 parts by weight of the solid content of the polyalkylene carbonate. The catalyst components remaining in the composition were also at the same level as in Example 1.

[0158] Comparative Example 3 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 solid content of the polyalkylene carbonate. The catalyst components remaining in the composition were also at the same level as in Example 1.

[0159] Comparative Example 4 A polyethylene carbonate resin composition was produced in the same manner as in Example 6, except that 0.0005 parts by weight of maleic acid was added per 100 parts by weight of the solids content of the polyalkylene carbonate. The catalyst components remaining in the composition were also at the same level as in Example 1.

[0160] Comparative Example 5 A high-pressure reactor was charged with 10 mg of the double metal cyanide catalyst prepared in the 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 polyalkylene carbonate. The polymer was then diluted with dioxolane solvent to a polyalkylene carbonate solids content of 20 wt%. The polymer was then filtered through a 0.2 μm filter to remove the catalyst, 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<1 ppm and Zn<2 ppm.

[0161] 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.

[0162] (1) Molecular weight characteristics Molecular weight characteristics were analyzed by gel permeation chromatography (GPC) using polystyrene as a standard.

[0163] 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

[0164] 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 determined using the following mathematical formula 2.

[0165] [Mathematical formula 2] Molecular weight change rate (%) = (|M W1 -M W2 | / M W1 ) x 100

[0166] In the above mathematical formula 2, M W1 is the weight average molecular weight of the polyalkylene carbonate resin composition before heat treatment measured by gel chromatography, and M W2 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.

[0167] (2) Thermal stability The thermal stability was confirmed by analyzing the mass change using a TGA (thermogravimetric analyzer) and determining the mass change rate (mass loss rate) according to the following mathematical formula 1.

[0168] [Mathematical formula 1] Mass change rate (%) = (|W1-W2| / W1) x 100

[0169] In the above mathematical formula 1, W1 is the mass of the polyalkylene carbonate resin composition at time 0 of a 60-minute isothermal step at 200°C in a mass change analysis using a thermogravimetric analyzer, and W2 is the mass of the polyalkylene carbonate resin composition at time 60 of a 60-minute isothermal step at 200°C.

[0170] Specifically, the mass change analysis was performed using a thermogravimetric analyzer (TGA2, Mettler Toledo) in the following steps.

[0171] 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: Heat from 150°C to 200°C (10°C / min) 4) 4-step: Isothermal at 200°C for 60 minutes

[0172] [Table 1]

[0173] As shown in Table 1, the polyethylene carbonate resin compositions of Examples 1 to 7 had a molecular weight change rate of 55% or less and a mass change rate of 10% or less, and it was confirmed that decomposition due to heat treatment was significantly reduced compared to the comparative example.

[0174] Specifically, the polyethylene carbonate resin compositions of Examples 1 to 7 had significantly reduced molecular weight and mass changes due to heat treatment, with molecular weight change rates of about 56% to 79% and mass change rates of about 1% to 7%, respectively, compared to the polyethylene carbonate resin composition of Comparative Example 1, which did not contain an organic acid. This confirms that the polyalkylene carbonate resin composition of the present invention, which contains an organic acid, inactivates residual catalyst components, thereby suppressing thermal decomposition and significantly improving thermal stability.

[0175] Furthermore, in Comparative Examples 2 and 3, where an organic acid is included in an amount exceeding the upper limit of the range of suitable amounts proposed in the present invention and the weight ratio of the organic acid to the residual catalyst component exceeds the upper limit, the molecular weight change rate is 62% and 58%, respectively, indicating a reduced effect in inhibiting thermal decomposition of the polymer chain. In Comparative Example 4, where the amount is below the lower limit of the range of suitable amounts, the molecular weight change rate is 61% and the mass change rate is 38%, indicating a minimal effect in inhibiting thermal decomposition. This confirms that when an organic acid is included in an amount outside the range proposed in the present invention, it actually accelerates thermal decomposition or has no effect on catalyst deactivation.

[0176] Furthermore, in the case of the polyethylene carbonate resin composition of Comparative Example 5, which was prepared by including a catalyst removal step, the catalyst component remaining in the composition was significantly reduced compared to the Examples, but the mass change rate was about 4 to 21 times higher than that of the Examples. This shows that the polyalkylene carbonate resin composition according to the present invention has a more economical process and better thermal stability than the polyalkylene carbonate resin composition containing an organic acid at a specific content according to the present invention.

Claims

1. a polyalkylene carbonate; and an organic acid, The polyalkylene carbonate resin composition comprises 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 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. further comprising a metal element derived from a double metal cyanide compound; 2. The polyalkylene carbonate resin composition according to claim 1, wherein the weight ratio of the organic acid to the metal element (organic acid / metal element) is 0.05 to 23.

00.

4. 4. The polyalkylene carbonate resin composition according to claim 3, wherein the weight ratio of the organic acid to the metal element (organic acid / metal element) is 0.05 to 14.

00.

5. 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.

6. the double metal cyanide compound comprises a component derived from a metal cyanide complex and a component derived from a metal salt; The metal cyanide complex is represented by the following chemical formula 1: The polyalkylene carbonate resin composition according to claim 3 , wherein the metal salt is represented by the following chemical formula 2: [Chemical formula 1] Y a M' (CCN) b In the above Chemical Formula 1, 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); Y is an alkali metal ion or an alkaline earth metal ion; a is an integer from 1 to 4 and b is an integer from 4 to 6, the values ​​of a and b being selected so that the metal cyanide complex is electrically neutral; [Chemical formula 2] M(X) n In the above Chemical Formula 2, M is 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); X is any one anion selected from the group consisting of halide, hydroxide, sulfate, carbonate, cyanate, oxalate, thiocyanate, isocyanate, isothiocyanate, carboxylate, and nitrate; n is a number that satisfies the valence state of M.

7. 7. The polyalkylene carbonate resin composition according to claim 6, wherein the metal cyanide complex is potassium hexacyanocobaltate(III), potassium hexacyanoferrate(II), potassium hexacyanoferrate(III), calcium hexacyanocobaltate(III), or lithium hexacyanoiridate(III).

8. 7. The polyalkylene carbonate resin composition according to claim 6, wherein the metal salt is at least one selected from the group consisting of 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, and nickel (II) nitrate.

9. The polyalkylene carbonate resin composition according to claim 1, wherein the mass change rate defined by the following mathematical formula 1 is 10% or less: [Mathematical formula 1] Mass change rate (%) = (| W 1 -W 2 | / W 1 ) x 100 In the above mathematical formula 1, W 1 is the mass of the polyalkylene carbonate resin composition at time 0 in a 60-minute isothermal stage at 200°C in a mass change analysis using a thermogravimetric analyzer, and W 2 is the mass of the polyalkylene carbonate resin composition at 60 minutes in a 60 minute 200°C isothermal step.

10. 2. The polyalkylene carbonate resin composition according to claim 1, wherein the rate of change in molecular weight defined by the following mathematical formula 2 is 55% or less. [Mathematical formula 2] Molecular weight change rate (%) = (|M W1 -M W2 | / M W1 )×100 In the above mathematical formula 2, M W1 is the weight average molecular weight of the polyalkylene carbonate resin composition before heat treatment measured by gel chromatography, and M W2 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.

11. The polyalkylene carbonate resin composition according to claim 1, wherein the polyalkylene carbonate comprises a repeating unit represented by the following chemical formula 3 and a repeating unit represented by the following chemical formula 4: 【Chemistry 12】 【Chemistry 13】 In the chemical formula 3 and the chemical formula 4, 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.

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

13. 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.

14. 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.

15. polymerizing an alkylene oxide compound and carbon dioxide in a solvent in the presence of a catalyst to produce a polymer comprising a polyalkylene carbonate; adding an organic acid to the polymer and stirring; 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 solid content of the polyalkylene carbonate in the polymer.

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

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

18. The method for producing a polyalkylene carbonate resin composition according to claim 15, wherein the polymerization is carried out at a temperature ranging from 50°C to 120°C.

19. The complexing agent may be cyclobutanol, cyclopentanol, cyclohexanol, cycloheptanol, cyclooctanol, 1-methylcyclopentanol, 2-methylcyclopentanol, 3-methylcyclopentanol, 1-ethylcyclopentanol, 2-ethylcyclopentanol, 3-ethyl ...2-ethylcyclopentanol, 2-ethylcyclopentanol, 2-ethylcyclopentanol, 2-ethylcyclopentanol, 2-ethylcyclopentanol, 2-ethylcyclopentanol, 2-ethylcyclopentanol, 2-ethylcyclopentanol, 2-ethylcyclopentanol, 2-ethylcyclopentanol, 2-ethylcyclopentanol, 2-ethylcyclopentanol, 2-ethylcyclopentanol, 2-ethylcyclopentanol, 2-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 15, 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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