Polyalkylene carbonate resin composition and method for manufacturing same

Abstract

The present invention relates to a polyalkylene carbonate resin composition having excellent thermal stability and a method for preparing the same, and to a polyalkylene carbonate resin composition comprising a polyalkylene carbonate and an organic acid, in which the content of the polyalkylene carbonate in the polyalkylene carbonate resin composition is 100 parts by weight, and the content of the organic acid in the polyalkylene carbonate resin composition is 100 parts by weight, and to a method for preparing the same. And 0.001 parts by weight to less than 0.5 parts by weight of the organic acid.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2023-0015651, filed on February 6, 2023, and Korean Patent Application Nos. 10-2023-0082943 and 10-2023-0082944, filed on June 27, 2023, which are hereby incorporated by reference into this specification in their entirety. Technical Field

[0003] The present invention relates to a polyalkylene carbonate resin composition with excellent thermal stability and a method for preparing the same. Background Art

[0004] Since the Industrial Revolution, humans have consumed vast quantities of fossil fuels to build modern society. However, this has led to an increase in atmospheric carbon dioxide concentrations through environmental damage, including deforestation. Since this increase in carbon dioxide concentration contributes to the greenhouse effect, it is crucial to reduce atmospheric carbon dioxide concentrations, which contribute significantly to global warming. Consequently, various studies are underway to regulate and sequester carbon dioxide emissions.

[0005] Recently, polyalkylene carbonate resins derived from the polymerization of carbon dioxide and epoxides have become a hot topic as biodegradable resins. Specifically, methods for preparing polyalkylene carbonate resins using carbon dioxide can reduce global warming by fixing carbon dioxide in the air, and are also being actively studied for use as a carbon source.

[0006] However, due to low thermal stability, polyalkylene carbonate resins thermally decompose at temperatures above 180 °C, which greatly limits industrial applications.

[0007] Furthermore, in order to prepare polyalkylene carbonate resins, a catalyst is required in addition to carbon dioxide and epoxide. As a typical heterogeneous catalyst, a double metal cyanide catalyst composed of a zinc dicarboxylate-based catalyst such as a zinc glutarate catalyst combined with a dicarboxylic acid and a complex of Co, Zn, Al, etc. is used.

[0008] If the catalyst remains in the resin, the decomposition of the polymer chain will be accelerated during the heat treatment of the resin, resulting in further deterioration of the thermal stability of the polyalkylene carbonate resin. Therefore, various purification technologies need to be developed to remove the catalyst after polymerization.

[0009] For example, CN 103842406 B discloses a method for purifying polyalkylene carbonate, wherein the polyalkylene carbonate is prepared in an organic solvent in the presence of a catalyst, the organic solvent is removed to form polyalkylene carbonate particles, an organic solvent-free acid aqueous solution containing 0.01-5% by weight of acid is added thereto, followed by solid-liquid mixing, heating, and drying. However, the solid-liquid mixing method using the acid aqueous solution leaves the polyalkylene carbonate in a particle (solid) state in the acid aqueous solution, and there is a problem of low deactivation efficiency of the catalyst remaining in the polyalkylene carbonate and the need for excessive acid.

[0010] [Prior art literature]

[0011] (Patent Document)

[0012] (Patent Document 1) CN 103842406 B (November 2, 2016) Summary of the Invention

[0013] Technical issues

[0014] An object of the present invention is to provide a polyalkylene carbonate resin composition having excellent thermal stability.

[0015] Furthermore, an object of the present invention is to provide a method for preparing the polyalkylene carbonate resin composition.

[0016] Technical Solution

[0017] In order to solve the above-mentioned problems, the present invention provides a polyalkylene resin composition and a method for preparing the same.

[0018] (1) The present invention provides a polyalkylene carbonate resin composition comprising: 100 parts by weight of polyalkylene carbonate; and 0.001 parts by weight to less than 0.5 parts by weight of an organic acid.

[0019] (2) The present invention provides the polyalkylene carbonate resin composition according to (1), which contains 0.05 to 0.1 parts by weight of the organic acid.

[0020] (3) The present invention provides the polyalkylene carbonate resin composition according to (1) or (2), further comprising a metal element derived from a double metal cyanide, wherein the weight ratio of the organic acid to the metal element (organic acid / metal element) is 0.05 to 23.00.

[0021] (4) The present invention provides the polyalkylene carbonate resin composition according to any one of (1) to (3), wherein the weight ratio of the organic acid to the metal element (organic acid / metal element) is 0.05 to 14.00.

[0022] (5) The present invention provides the polyalkylene carbonate resin composition according to any one of (1) to (4), wherein the organic acid is at least one selected from citric acid, tartaric acid, ascorbic acid, and maleic acid.

[0023] (6) The present invention provides a polyalkylene carbonate resin composition according to any one of (3) to (5), wherein 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 formula 1, and the metal salt is represented by the following formula 2.

[0024] [Formula 1]

[0025] YaM`(CN) b

[0026] In formula 1,

[0027] M' is at least one selected from 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),

[0028] Y is an alkali metal ion or an alkaline earth metal ion,

[0029] a is an integer from 1 to 4, b is an integer from 4 to 6, and the values ​​of a and b are selected so that the metal cyanide complex becomes electrically neutral,

[0030] [Formula 2]

[0031] M(X) n

[0032] In formula 2,

[0033] 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),

[0034] X is one selected from the group consisting of halides, hydroxides, sulfates, carbonates, cyanates, oxalates, thiocyanates, isocyanates, isothiocyanates, carboxylates, and nitrates,

[0035] n is a number that satisfies the valence of M.

[0036] (7) The present invention provides a polyalkylene carbonate resin composition according to (6), wherein the metal cyanide complex is potassium hexacyanocobaltate (III), potassium hexacyanoferrate (II), potassium hexacyanoferrate (III), calcium hexacyanocobaltate (III) or lithium hexacyanoiridate (III).

[0037] (8) The present invention provides a polyalkylene carbonate resin composition according to (6), wherein the metal salt is at least one selected from zinc (II) chloride, zinc (III) chloride, 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.

[0038] (9) The present invention provides the polyalkylene carbonate resin composition according to any one of (1) to (8), wherein the mass change rate defined by the following mathematical equation 1 is 10% or less.

[0039] [Mathematical equation 1]

[0040] Mass change rate (%) = (|W1-W2| / W1) × 100

[0041] In mathematical equation 1,

[0042] W1 is the mass of the polyalkylene carbonate resin composition at 0 minutes in a 60-minute 200°C isothermal step in mass change analysis using a thermogravimetric analyzer, and W2 is the mass of the polyalkylene resin composition at 60 minutes in a 60-minute 200°C isothermal step.

[0043] (10) The present invention provides the polyalkylene carbonate resin composition according to any one of (1) to (9), wherein the molecular weight change rate defined by the following mathematical equation 2 is 55% or less.

[0044] [Mathematical equation 2]

[0045] Molecular weight change rate (%) = (|Mw1-Mw2| / Mw1) × 100

[0046] In mathematical equation 2,

[0047] Mw1 is the weight average molecular weight of the polyalkylene carbonate resin composition measured by gel chromatography before heat treatment, and Mw2 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.

[0048] (11) The present invention provides the polyalkylene carbonate resin composition according to any one of (1) to (10), wherein the polyalkylene carbonate contains a repeating unit represented by the following formula 3 and a repeating unit represented by the following formula 4.

[0049] [Formula 3]

[0050]

[0051] In Equation 3 and Equation 4,

[0052] R1 to R8 are each independently hydrogen, a linear alkyl group of 1 to 20 carbon atoms, a branched alkyl group of 3 to 20 carbon atoms, an aryl group of 6 to 20 carbon atoms, an alkenyl group of 2 to 20 carbon atoms, or a cycloalkyl group of 3 to 20 carbon atoms,

[0053] * indicates the connecting part between repeating units,

[0054] x and y are mole fractions, where x is from 0.70 to 1.00, y is from 0.00 to 0.30, and x+y is 1.

[0055] (12) The present invention provides the polyalkylene carbonate resin composition according to any one of (1) to (11), wherein the polyalkylene carbonate has a glass transition temperature of -10°C to 50°C.

[0056] (13) The present invention provides a polyalkylene carbonate resin composition according to any one of (1) to (12), wherein the polyalkylene carbonate is at least one selected from polyethylene carbonate, polypropylene carbonate, polypentylene carbonate, polyhexylene carbonate, polyoctylene carbonate and polycyclohexylene carbonate.

[0057] (14) The present invention provides a polyalkylene carbonate resin composition according to any one of (1) to (13), wherein the polyalkylene carbonate has a cyclic carbonate content of 0.5% by weight to 15% by weight.

[0058] (15) The present invention provides a method for preparing a polyalkylene carbonate resin composition, the method comprising: a step of polymerizing an alkylene oxide compound and carbon dioxide in a solvent in the presence of a catalyst to prepare a polymer containing polyalkylene carbonate; a step of adding an organic acid to the polymer and stirring; and a step of removing the solvent, wherein the organic acid is added in an amount of 0.001 parts by weight to less than 0.5 parts by weight based on 100 parts by weight of the solid content of the polyalkylene carbonate in the polymer.

[0059] (16) The present invention provides a method for preparing a polyalkylene carbonate resin composition according to (15), wherein the catalyst comprises a double metal cyanide and a complexing agent.

[0060] (17) The present invention provides a method for preparing a polyalkylene carbonate resin composition according to (15) or (16), wherein a solvent is additionally added to the polymer so that the solid content of the polyalkylene carbonate in the polymer before the addition of the organic acid is 10 wt % to 40 wt %.

[0061] (18) The present invention provides a method for preparing a polyalkylene carbonate resin composition according to any one of (15) to (17), wherein the polymerization is carried out at a temperature in the range of 30°C to 120°C.

[0062] (19) The present invention provides a method for preparing a polyalkylene carbonate resin composition according to any one of (15) to (18), wherein the complexing agent is at least one selected from the group consisting of cyclobutanol, cyclopentanol, cyclohexanol, cycloheptanol, cyclooctanol, 1-methylcyclopentanol, 2-methylcyclopentanol, 3-methylcyclopentanol, 1-ethylcyclopentanol, 2-ethylcyclopentanol, 3-ethylcyclopentanol, 1-propylcyclopentanol, 2-propylcyclopentanol, 3-propylcyclopentanol, 1-butylcyclopentanol, 2-butylcyclopentanol, 3-butylcyclopentanol, 1-isopropylcyclopentanol, 2-isopropylcyclopentanol, 3-isopropylcyclopentanol, 1-(prop-2-yl)cyclopentanol, 2,2-dimethylcyclopentanol, 2,3-dimethylcyclopentanol, 3,3-dimethylcyclopentanol, 1,2-dimethylcyclopentanol, 1,3-dimethylcyclopentanol, 1-methylcyclohexanol Alcohol, 1-ethylcyclohexanol, 1-propylcyclohexanol, 1-butylcyclohexanol, 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, 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-cyclohexanol, 3,4-dimethyl-1-cyclohexanol, 1-methylcycloheptanol, 2-methylcycloheptanol, 3-methylcycloheptanol and 4-methylcycloheptanol.

[0063] Beneficial effects

[0064] The polyalkylene carbonate resin composition according to the present invention includes 0.001 to less than 0.5 parts by weight of an organic acid based on 100 parts by weight of the polyalkylene carbonate, and the activity of the catalyst remaining in the resin composition can be deactivated by the organic acid, thereby improving thermal stability.

[0065] In addition, the polyalkylene carbonate resin composition according to the present invention contains an organic acid, and the organic acid is present in a specific weight ratio relative to the residual catalyst component, and therefore, the activity of the catalyst remaining in the resin composition can be further deactivated, and a further improved thermal stability effect is exhibited. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] The accompanying drawings illustrate specific embodiments of the present invention and, together with the above content of the present invention, are used to further understand the technical concept of the present invention. Therefore, the present invention should not be interpreted as being limited to the matters described in the drawings.

[0067] Figure 1 It is a graph showing the results of mass change analysis of the polyethylene carbonate resin compositions prepared in Examples 1 to 7 using a thermogravimetric analyzer.

[0068] Figure 2 It is a graph showing the results of mass change analysis of the polyethylene carbonate resin compositions prepared in Example 1 and Comparative Examples 1 to 5 using a thermogravimetric analyzer. DETAILED DESCRIPTION

[0069] Hereinafter, the present invention will be explained in more detail to help understanding of the present invention.

[0070] It should be understood that the words or terms used in the description and claims of the present invention should not be understood as having the meanings defined in commonly used dictionaries. It will be understood that based on the inventors' ability to appropriately define the meanings of the words to best illustrate the principles of the present invention, the words or terms should be understood as having the same meanings as those in the technical concept of the present invention.

[0071] Definition of terms

[0072] The term "alkyl group" in the specification may refer to a monovalent aliphatic saturated hydrocarbon.

[0073] The term "aryl group" in the specification may refer to a cyclic aromatic hydrocarbon, and may include both a monocyclic aromatic hydrocarbon forming one ring and a polycyclic aromatic hydrocarbon combining two or more rings.

[0074] The term "alkenyl" in the specification may refer to a monovalent aliphatic unsaturated hydrocarbon including one or two or more double bonds.

[0075] The term "cycloalkyl group" in the specification may include both cyclic saturated hydrocarbons and cyclic unsaturated hydrocarbons containing one or two or more unsaturated bonds.

[0076] Measurement method

[0077] In the specification, molecular weight properties were analyzed by gel permeation chromatography using polystyrene as a standard material, specifically, measured using GPC (Waters 1515 isocratic HPLC pump, Waters 2414 refractive index detector, Waters Co.) under the following conditions.

[0078] Column: Two Agilent PLgel MIXED-B columns (7.5 mm x 300, 10 μm)

[0079] Solvent: Chloroform

[0080] Flow rate: 0.7 ml / min

[0081] Column temperature: 40°C

[0082] Sample: 4.0 mg / 1.0 ml chloroform

[0083] Sample injection volume: 20 μl

[0084] Standard material: Polystyrene

[0085] In this specification, mass change analysis is performed using a thermogravimetric analyzer (TGA), specifically, using TGA (TGA2, Mettler Toledo) under the following conditions.

[0086] 1) Step 1: Temperature rises from 30°C to 50°C (10°C / min)

[0087] 2) Step 2: Heat at 150°C for 5 minutes

[0088] 3) Step 3: Temperature rises from 150°C to 200°C (10°C / min)

[0089] 4) Step 4: Incubate at 200°C for 60 minutes

[0090] Polyalkylene carbonate resin composition

[0091] The present invention provides a polyalkylene carbonate resin composition having improved thermal stability by suppressing thermal decomposition.

[0092] The 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 parts by weight to less than 0.5 parts by weight of an organic acid.

[0093] Furthermore, a polyalkylene carbonate resin composition according to one embodiment of the present invention is characterized by comprising: polyalkylene carbonate; an organic acid; and a metal element derived from a double metal cyanide, wherein a weight ratio of the organic acid to the metal element (organic acid / metal element) is 0.05 to 23.00.

[0094] Specifically, the polyalkylene carbonate resin composition according to one embodiment of the present invention may have a weight ratio of the organic acid to the metal element (organic acid / metal element) of 0.05 to 14.00, 0.05 to 5.00, or 0.05 to 1.00.

[0095] Polyalkylene carbonate resins are produced using carbon dioxide as a raw material and have attracted significant attention as biodegradable resins. However, due to their low thermal stability, they thermally decompose at temperatures above 180°C, significantly limiting their industrial applications. Furthermore, in addition to carbon dioxide and epoxide, a catalyst is required to produce polyalkylene carbonate resins. If the catalyst remains in the resin, the decomposition of the polymer chains is accelerated during heat treatment of the resin, resulting in a deterioration in the thermal stability of the polyalkylene carbonate resin. Consequently, various purification technologies need to be developed to remove the catalyst after polymerization.

[0096] However, the polyalkylene carbonate resin composition according to one embodiment of the present invention contains a certain amount of organic acid by directly adding a specific amount of organic acid to the polymer after polymerizing polyalkylene carbonate, the residual catalyst can be deactivated without additional processes such as extraction and precipitation, and thus, its thermal decomposition can be suppressed and its thermal stability can become excellent.

[0097] Hereinafter, the polyalkylene carbonate resin composition according to the present invention will be specifically explained by dividing it into respective components contained therein.

[0098] Polyalkylene carbonate

[0099] In the present invention, the polyalkylene carbonate is a polymer prepared by polymerizing an alkylene oxide compound with carbon dioxide, and may include a repeating unit represented by Formula 3 and a repeating unit represented by Formula 4.

[0100] [Formula 3]

[0101]

[0102] [Formula 4]

[0103]

[0104] In Equation 3 and Equation 4,

[0105] R1 to R8 are each independently hydrogen, a straight-chain alkyl group of 1 to 20 carbon atoms, a branched-chain alkyl group of 3 to 20 carbon atoms, an aryl group of 6 to 20 carbon atoms, an alkenyl group of 2 to 20 carbon atoms, or a cycloalkyl group of 3 to 20 carbon atoms, * represents a link between repeating units, and x and y are mole fractions, wherein x is 0.70 to 1.00, y is 0.00 to 0.30, and x+y is 1.

[0106] Furthermore, x may be between 0.80 and 1.00, and y may be between 0.00 and 0.20. Preferably, x may be between 0.90 and 1.00, and y may be between 0.00 and 0.10. If these ranges are met, the carbon dioxide fixation rate is high, which is effective in reducing greenhouse gases and also contributes to biodegradability. Furthermore, when the polyalkylene carbonate according to the present invention is formed into a film, the film exhibits low oxygen permeability, resulting in excellent barrier properties.

[0107] The polyalkylene carbonate may be at least one selected from polyethylene carbonate, polypropylene carbonate, polypentylene carbonate, polyhexylene carbonate, polyoctylene carbonate, and polycyclohexylene carbonate. In addition, in Formula 1, R1 to R8 are each independently hydrogen, a linear alkyl group of 1 to 20 carbon atoms, a branched alkyl group of 3 to 20 carbon atoms, an aryl group of 6 to 20 carbon atoms, an alkenyl group of 2 to 20 carbon atoms, or a cycloalkyl group of 3 to 20 carbon atoms, and can be selected as a suitable functional group in consideration of the physical properties of the resin to be ultimately obtained.

[0108] In addition, the repeating unit represented by Formula 3 may be a repeating unit represented by Formula 5 below.

[0109] [Formula 5]

[0110]

[0111] In Formula 5, R1 to R4 are each independently hydrogen or a linear alkyl group of 1 to 10 carbon atoms, and x and * are the same as defined in Formula 3.

[0112] More specifically, the repeating unit represented by Formula 3 may be a repeating unit represented by Formula 6 or Formula 7 below.

[0113] [Formula 6]

[0114]

[0115] [Formula 7]

[0116]

[0117] In Formula 6 and Formula 7, x and * are the same as defined in Formula 1.

[0118] In addition, the repeating unit represented by Formula 4 may be a repeating unit represented by Formula 8 below.

[0119] [Formula 8]

[0120]

[0121] In Formula 8, R5 to R8 are each independently hydrogen or a linear alkyl group of 1 to 10 carbon atoms, and y and * are the same as defined in Formula 4.

[0122] More specifically, the repeating unit represented by Formula 4 may be a repeating unit represented by Formula 9 or Formula 10 below.

[0123] [Formula 9]

[0124]

[0125] [Equation 10]

[0126]

[0127] In Formula 9 and Formula 10, y and * are the same as defined in Formula 2.

[0128] The glass transition temperature (Tg) of the polyalkylene carbonate of the present invention is -10 to 50° C., 0 to 50° C., or 10 to 50° C. If the above range is satisfied, processability of the polyalkylene carbonate at room temperature may be excellent.

[0129] In another embodiment, in Formula 3 and Formula 4, if R1 to R8 are each independently hydrogen, the glass transition temperature (Tg) of the polyalkylene carbonate may be 0°C to 20°C.

[0130] In another embodiment, in Formula 3 and Formula 4, if R1 to R8 are each independently a linear alkyl group of 1 to 20 carbon atoms, a branched alkyl group of 3 to 20 carbon atoms, an aryl group of 6 to 20 carbon atoms, an alkenyl group of 2 to 20 carbon atoms, or a cycloalkyl group of 3 to 20 carbon atoms, the glass transition temperature (Tg) of the polyalkylene carbonate may be 30°C to 50°C or 35°C to 50°C.

[0131] In addition, based on the total weight of the polyalkylene carbonate, the cyclic carbonate content can be 0.5 wt % to 15.0 wt %, 0.5 wt % to 10.0 wt % or 0.5 wt % to 5.0 wt %. If the above range is met, the defect of lowering the glass transition temperature caused by the cyclic carbonate as a softening agent can be minimized, and the effect of excellent mechanical properties can be obtained.

[0132] The cyclic carbonate content can be determined by using 1H-NMR spectrometer (500MHz spectrometer, Jeol Co.) was used to measure the polyalkylene carbonate resin sample of 10 mg dissolved in chloroform-d6 solvent. 1 As a result of H-NMR spectrometry, a peak at around 4.5 ppm, namely, a cyclic carbonate peak, was confirmed. As shown in the following mathematical equation 3, the cyclic carbonate content can be calculated using the values ​​of the carbonate peak area and the ether peak area.

[0133] [Mathematical equation 3]

[0134]

[0135] In mathematical equation 3, A, B, C, N and CO2 content can be defined as follows.

[0136] 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 units x 44) / [(molar fraction of carbonate units x 44) + (molar mass of alkylene oxide x 100)]

[0137] organic acids

[0138] In one embodiment of the present invention, the organic acid plays a role in deactivating the catalyst, and may be included in the polyalkylene carbonate resin composition at 0.001 parts by weight to less than 0.5 parts by weight based on 100 parts by weight of the polyalkylene carbonate.

[0139] Specifically, the polyalkylene carbonate resin composition may include 0.05 parts by weight to 0.1 parts by weight of the organic acid.

[0140] If the organic acid is included within the above range, the catalyst may be effectively deactivated without causing a problem of accelerating thermal decomposition of the polyalkylene carbonate, and the thermal stability of the composition may be effectively improved.

[0141] Meanwhile, the polyalkylene carbonate resin composition according to one embodiment of the present invention can be prepared by a preparation method which will be explained later in which a step of removing the organic acid is not performed after the addition of the organic acid, and the content of the organic acid in the polyalkylene carbonate resin composition can be the same as the amount added during the preparation process.

[0142] In another embodiment, in the present invention, the organic acid content in the polyalkylene carbonate resin composition can be confirmed by a component quantitative analysis method well known in the art, for example, a quantitative analyzer such as UPLC / MS / MS, HPLC / RI, and UPLC-QTOF / MS can be used.

[0143] In addition, regarding the organic acid content, there was no difference between the amount added during the preparation and the content analyzed using a quantitative analyzer, or it was within the error range (±10%).

[0144] Furthermore, the organic acid may be at least one selected from citric acid, tartaric acid, ascorbic acid, and maleic acid.

[0145] Metal components

[0146] In one embodiment of the present invention, the metal component may be a residue of a catalyst used in the process of preparing the polyalkylene carbonate resin composition, that is, a residual catalyst component.

[0147] Specifically, the metal component is a metal component derived from a double metal cyanide, and the double metal cyanide contains a component derived from a metal cyanide complex and a component derived from a metal salt.

[0148] More specifically, the double metal cyanide may be derived from a complex and a metal salt, and the metal cyanide complex may be water-soluble and may be represented by Formula 1 below.

[0149] [Formula 1]

[0150] Y a M`(CN) b

[0151] In Formula 1, M' can be at least one selected from 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, at least one selected from Co(II), Co(III), Fe(II), Fe(III), Cr(III), Ir(III) and Ni(II), more specifically, Co(II) or Co(III). In addition, 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, and the values ​​of a and b are selected so that the metal cyanide complex is electrically neutral.

[0152] In another embodiment, the metal cyanide complex may be potassium hexacyanocobaltate (III), potassium hexacyanoferrate (II), potassium hexacyanoferrate (III), calcium hexacyanocobaltate (III), or lithium hexacyanoiridate (III), preferably potassium hexacyanocobaltate (III).

[0153] The metal salt may be water-soluble and may be represented by Formula 2 below.

[0154] [Formula 2]

[0155] M(X) n

[0156] In Formula 2, M is a transition metal, preferably selected from at least one 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 selected from at least one of Zn(II), Fe(II), Co(II), and Ni(II). X is selected from one of halides, hydroxides, sulfates, carbonates, cyanates, oxalates, thiocyanates, isocyanates, isothiocyanates, carboxylates, and nitrates, and n is a number that satisfies the valence of M.

[0157] In another embodiment, the metal salt can be zinc (II) chloride, zinc (III) chloride, 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, preferably, zinc (II) chloride, zinc (III) chloride, zinc bromide or zinc iodide.

[0158] Polyalkylene carbonate resin composition

[0159] The polyalkylene carbonate resin composition according to one embodiment of the present invention may have a mass change rate defined by the following Mathematical Equation 1 of 10% or less.

[0160] [Mathematical equation 1]

[0161] Mass change rate (%) = (|W1-W2| / W1) × 100

[0162] In Mathematical Equation 1, W1 is the mass of the polyalkylene carbonate resin composition at the 0-minute point in a 60-minute 200° C. isothermal step in a mass change analysis using a thermogravimetric analyzer, and W2 is the mass of the polyalkylene carbonate resin composition at the 60-minute point in the 60-minute 200° C. isothermal step.

[0163] In another embodiment, the polyalkylene carbonate resin composition may have a molecular weight variation rate defined by the following Mathematical Equation 2 of 55% or less.

[0164] [Mathematical equation 2]

[0165] Molecular weight change rate (%) = (|Mw1-Mw2| / Mw1) × 100

[0166] In Mathematical Equation 2, Mw1 is the weight average molecular weight of the polyalkylene carbonate resin composition measured by gel chromatography before heat treatment, and Mw2 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.

[0167] Method for preparing polyalkylene carbonate resin composition

[0168] The present invention provides a method for preparing a polyalkylene carbonate resin composition.

[0169] The method for preparing a polyalkylene carbonate resin composition according to one embodiment of the present invention is characterized in that it includes: (S1) polymerizing an alkylene oxide compound with carbon dioxide in a solvent in the presence of a catalyst to prepare a polymer containing polyalkylene carbonate; (S2) adding an organic acid to the polymer and stirring; and (S3) removing the solvent, wherein, based on the solid content of the polyalkylene carbonate in 100 parts by weight of the polymer, 0.001 parts by weight to less than 0.5 parts by weight of the organic acid are added. Here, the preparation method of one embodiment of the present invention does not include an additional process for removing the catalyst, such as extraction and precipitation after polymerization, and the polymer contains the catalyst.

[0170] In the following, the method is divided into individual steps and explained in more detail.

[0171] Step (S1)

[0172] Step (S1) is a step of forming polyalkylene carbonate and preparing a polymer including the polyalkylene carbonate, and can be performed by polymerizing an alkylene oxide compound with carbon dioxide in a solvent in the presence of a catalyst.

[0173] The catalyst comprises a double metal cyanide and a complexing agent, and the double metal cyanide and complexing agent commonly used in the art can be used without limitation.

[0174] For example, a double metal cyanide may be derived from a metal cyanide complex and a metal salt, and the metal cyanide complex may exhibit water solubility.

[0175] Specific double metal cyanide compounds are as described above.

[0176] The catalyst according to the present invention can be represented by Formula 11 below.

[0177] [Equation 11]

[0178] M 2 p [M 1 (CN)6] q ·dM2 (X) r ·eL·fH2O

[0179] In formula 11, M 1 and M 2 Each of p, q, d, r, e and f is independently an integer from 1 to 6.

[0180] More specifically, the catalyst according to the present invention can be represented by Formula 12 below.

[0181] [Equation 12]

[0182] Zn3[Co(CN)6]2·gZnCl2·hL·iH2O

[0183] In Formula 12, L is cyclobutanol, cyclopentanol, cyclohexanol, cycloheptanol, or cyclooctanol, and g, h, and i are each independently an integer of 1 to 6.

[0184] In addition, the complexing agent may be any complexing agent commonly used in the art without particular limitation, for example, at least one selected from ethanol, isopropanol, n-butanol, isobutanol, sec-butanol and tert-butanol.

[0185] In another embodiment, the complexing agent may be a compound represented by Formula 13 below.

[0186] [Equation 13]

[0187]

[0188] In formula 13,

[0189] R 9a and R 9b Each independently represents a single bond or an alkylene group of 1 to 5 carbon atoms, wherein R 9a and R 9b At least one of the groups is an alkylene group having 1 to 5 carbon atoms.

[0190] R 9c and R 9d are each independently a hydrogen atom or an alkyl group of 1 to 6 carbon atoms,

[0191] n is an integer from 0 to 2.

[0192] Specifically, in Formula 13, R 9a and R 9b can each independently be a single bond or an alkylene group of 1 to 3 carbon atoms, wherein R 9a and R 9b At least one of them is an alkylene group with 1 to 3 carbon atoms, R 9cand R 9d Each is independently a hydrogen atom or an alkyl group of 1 to 4 carbon atoms, and n can be an integer of 0 to 2.

[0193] In another embodiment, in Formula 9, R 9a and R 9b R 9a and R 9b At least one of them may be an alkylene group with 1 to 3 carbon atoms, R 9c It can be a hydrogen atom, and n can be 0.

[0194] In another embodiment, the complexing agent may be a cycloalkyl alcohol of 3 to 12 carbon atoms, specifically, a cycloalkyl alcohol of 4 to 10 carbon atoms or 5 to 7 carbon atoms.

[0195] More specifically, the complexing agent may be selected from the group consisting of cyclobutanol, cyclopentanol, cyclohexanol, cycloheptanol, cyclooctanol, 1-methylcyclopentanol, 2-methylcyclopentanol, 3-methylcyclopentanol, 1-ethylcyclopentanol, 2-ethylcyclopentanol, 3-ethylcyclopentanol, 1-propylcyclopentanol, 2-propylcyclopentanol, 3-propylcyclopentanol, 1-butylcyclopentanol, 2-butylcyclopentanol, 3-butylcyclopentanol, 1-isopropylcyclopentanol, 2-isopropylcyclopentanol, 3-isopropylcyclopentanol, 1-(prop-2-yl)cyclopentanol, 2,2-dimethylcyclopentanol, 2,3-dimethylcyclopentanol, 3,3-dimethylcyclopentanol, 1,2-dimethylcyclopentanol, 1,3-dimethylcyclopentanol, 1-methylcyclohexanol, 1-ethylcyclohexanol, 1-propylcyclohexanol, 1-butylcyclohexanol, 2-methylcyclopentanol, 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, 2-isopropyl-1-cyclohexanol, 3-isopropyl-1-cyclohexanol At least one of cyclobutanol, cyclopentanol, cyclohexanol, cyclohexanol, cycloheptanol and cyclooctanol.

[0196] In another embodiment, the complexing agent may be at least one selected from cyclobutanol, cyclopentanol, cyclohexanol, cycloheptanol, and cyclooctanol.

[0197] At the same time, if the compound represented by Formula 13 is included in the catalyst as a complexing agent, a cycloalkane-type alcohol having a bulky structure is used as the complexing agent, and the crystal structure of the catalyst can be various, including cubic, amorphous and monoclinic systems. Therefore, by appropriately controlling the reaction rate of the epoxy compound and carbon dioxide, the proportion of the repeating unit containing carbon dioxide in the prepared polyalkylene carbonate is increased, the content of the cyclic carbonate by-product is reduced, and a polyalkylene carbonate with more excellent thermal stability and excellent processing properties can be obtained.

[0198] In addition, the catalyst may further contain an auxiliary complexing agent as needed. The auxiliary complexing agent may be a compound having a hydroxyl group, an amine group, an ester group or an ether group at the terminal.

[0199] The auxiliary complexing agent can improve the activity of the catalyst and can be, for example, at least one selected from polyacrylamide, poly(acrylamide-co-acrylic acid), polyacrylic acid, poly(acrylic acid-co-maleic acid), polyacrylonitrile, polyalkyl acrylates, polyalkyl methacrylates, polyvinyl methyl ether, polyvinyl ethyl ether, polyvinyl acetate, polyvinyl alcohol, poly-N-vinyl pyrrolidone, poly(N-vinyl pyrrolidone-co-acrylic acid), polyvinyl methyl ketone, poly(4-vinylphenol), poly(acrylic acid-co-styrene), oxazoline polymers, polyalkylene imines, maleic acid, maleic anhydride copolymers, hydroxyethyl cellulose, polyacetals, glycidyl ethers, glycosides, carboxylic acid esters of polyols, gallic acid, esters and amides.

[0200] In addition, the auxiliary complexing agent can be a compound prepared by ring-opening polymerization of a cyclic ether compound, an epoxy polymer or an oxetane polymer, for example, at least one selected from polyether, polyester, polycarbonate, polyalkylene glycol, polyalkylene glycol sorbitan ester and polyalkylene glycol glycidyl ether.

[0201] In addition, there is no particular limitation on the polymerization, but preferably, solution polymerization can be performed. Through solution polymerization, the reaction heat can be appropriately controlled, and the weight average molecular weight or viscosity of the target polyalkylene carbonate can be easily controlled.

[0202] The catalyst and the 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 range, the catalyst can exhibit high catalyst activity while minimizing byproducts and minimizing backbiting of the thermally prepared polyalkylene carbonate.

[0203] Furthermore, the polymerization of the alkylene oxide compound and carbon dioxide can be performed at a temperature ranging from 30° C. to 120° C., 40° C. to 110° C., or 50° C. to 100° C. If the above range is met, the polymerization time of the alkylene oxide compound and carbon dioxide can be controlled within 24 hours, thereby improving the production productivity.

[0204] In addition, the polymerization of the alkylene oxide compound and the carbon dioxide can be carried out within a pressure range of 5 to 50 bar, 10 to 40 bar, or 15 to 30 bar. If the above range is met, the ratio of the repeating unit containing carbon dioxide in the prepared polyalkylene carbonate can be high, and the effect of reducing the content of cyclic carbonate by-products can be achieved.

[0205] The alkylene oxide compound may be at least one compound selected from the group consisting of unsubstituted or substituted alkylene oxides having 2 to 20 carbon atoms, alkylene oxides having 1 to 5 carbon atoms, alkylene oxides having 4 to 20 carbon atoms, alkylene oxides having 1 to 5 carbon atoms, and styrene oxides having 8 to 20 carbon atoms, styrene oxides having 8 to 20 carbon atoms, and styrene oxides having 1 to 5 carbon atoms, such as ethylene oxide, propylene oxide, butylene oxide, pentane oxide, hexane oxide, octane oxide, decane oxide, dodecane oxide, tetradecane oxide, hexadecane oxide, octadecane oxide, butadiene monoxide, 1,2-epoxy-7-octene, epifluoropropane, epichlorohydrin, epibromopropane, isopropyl glycidyl ether, butyl glycidyl ether. At least one compound selected from the group consisting of glyceryl ether, tert-butyl glycidyl ether, 2-ethylhexyl glycidyl ether, allyl glycidyl ether, cyclopentene oxide, cyclohexene oxide, cyclooctene oxide, cyclododecene oxide, α-epoxypinane, 2,3-epoxynorbomene, limonene oxide, dieldrin, 2,3-epoxypropylbenzene, styrene oxide, phenylpropylene oxide, styrene oxide, chlorostilbene oxide, dichlorostilbene oxide, 1,2-epoxy-3-phenoxypropane, benzyloxymethyloxirane, glycidyl-methylphenyl ether, chlorophenyl-2,3-epoxypropyl ether, glycidyl methoxyphenyl ether, biphenyl glycidyl ether, and glycidyl naphthyl ether.

[0206] Furthermore, in the case of carrying out solution polymerization of an alkylene oxide compound with carbon dioxide, the alkylene oxide compound and the solvent may be miscible, and as the solvent, at least one selected from the group consisting of dichloromethane, dichloroethane, trichloroethane, tetrachloroethane, chloroform, acetonitrile, propionitrile, dimethylformamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, nitromethane, 1,3-dioxolane (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 propylene glycol methyl ether may be used.

[0207] The solvent and the 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 may be suitably used as a reaction medium, thereby increasing the productivity of the polyalkylene carbonate resin and minimizing by-products generated during the preparation process.

[0208] Step (S2)

[0209] Step (S2) is a step of adding an organic acid to the polymer containing polyalkylene carbonate prepared above and stirring.

[0210] The organic acid may be added at 0.001 parts by weight to less than 0.5 parts by weight based on 100 parts by weight of the solid content of the polyalkylene carbonate in the polymer, and specific organic acids are as described above.

[0211] Furthermore, stirring is a means of mixing the organic acid in the polymer to be uniformly distributed, and can be performed without significant restrictions as long as this purpose can be achieved.

[0212] At the same time, before adding the organic acid, a step of additionally adding a solvent to the polymer may be further performed so that the solid content of the polyalkylene carbonate in the polymer becomes 10% to 40% by weight. In this case, the viscosity of the polymer can be reduced and the organic acid can 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 at least one selected from the above-mentioned solvents.

[0213] Furthermore, since the preparation method according to one embodiment of the present invention does not include additional processes such as extraction and precipitation for removing catalyst components after polymerization, the process is simple and the cost for additional processes is reduced, thereby improving economic efficiency and productivity.

[0214] Step (S3)

[0215] Step (S3) is a solvent removal step for removing the solvent to prepare a polyalkylene carbonate resin composition.

[0216] Here, the removal of the solvent can be performed by common means in the art without specific limitation as long as the purpose of removing the solvent is achieved, and can be performed by, for example, heating at a temperature of 30° C. to 150° C. for 30 minutes to 10 hours.

[0217] Example

[0218] Hereinafter, the present invention will be explained in more detail by way of embodiments. However, the following embodiments are for illustrating the present invention, and the scope of the present invention is not limited thereto.

[0219] Preparation Example

[0220] In a first beaker with a volume of 500 ml, 11.45 g of zinc chloride, 30 ml of distilled water and 39 g of cyclohexanol were mixed to prepare a first mixed solution. In a second beaker with a volume of 250 ml, 4 g of potassium hexacyanocobaltate was dissolved in 100 ml of distilled water to prepare a second mixed solution. In a third beaker with a volume of 100 ml, 5 g of polypropylene glycol (Mw=3,000) and 23 g of cyclohexanol were dissolved in 2 ml of distilled water to prepare a third mixed solution. By using a mechanical stirrer, at 25 ° C, the second mixed solution was added dropwise to the first mixed solution over 1 hour, the third mixed solution was immediately injected, and then reacted for 1 hour. Then, the mixed product was separated using a high-speed centrifuge, and the separated precipitate was washed twice with a mixture of 70 ml of distilled water and 70 ml of cyclohexanol. Then, additional washing was carried out using 140 ml of cyclohexanol, and the thus washed precipitate was dried in a vacuum oven at 80° C. for 12 hours, ultimately obtaining 6.2 g of a double metal cyanide catalyst.

[0221] Example 1

[0222] 10 mg of the double metal cyanide catalyst prepared in the preparation example, 20 g of ethylene oxide and 10 g of dioxolane solvent were added to a high-pressure reactor. Then, carbon dioxide was injected into the reactor and a pressure of 30 bar was applied. The polymerization reaction was carried out at 70 ° C for 24 hours. After the reaction was completed, the unreacted carbon dioxide was removed to prepare a polymer containing polyalkylene carbonate. The product was then diluted in a dioxolane solvent to a solid content of polyalkylene carbonate in the polymer of 20% by weight. Based on the solid content of 100 parts by weight of polyalkylene carbonate, 0.02 parts by weight of citric acid was added and then stirred. The resultant was poured onto a tray and dried in a vacuum oven at 40 ° C for 6 hours to obtain a polyethylene carbonate resin composition. In this case, the catalyst components remaining in the composition were Co = 66 ppm and Zn = 150 ppm.

[0223] The contents of residual Co and Zn were measured by ICP analysis under the following conditions.

[0224] A 0.1 g portion of the composition was aliquoted into a Teflon container and weighed. 2 ml of nitric acid and 1 ml of sulfuric acid were added, and the container was capped and sealed. The composition was then dissolved using a Multiwave 7000 (Anton Parr Co.) at 220°C and 140 bar for 60 minutes, then at 280°C and 130 bar for 30 minutes, and then cooled to room temperature. The residue was removed using a 0.45 μm PTFE filter, and the resulting solution was diluted with tertiary ultrapure water to prepare a sample for analysis.

[0225] ICP analysis was performed using Thermo science iCAP PRO (Theremo science Co.) under the following conditions.

[0226] RF power: 1,200W

[0227] Nebulizer air flow: 0.7L / min

[0228] Auxiliary air flow: 0.5L / min

[0229] Cold air flow: 12L / min

[0230] Pump speed: 50 rpm

[0231] Radial observation height: 10.0mm

[0232] Internal standard: Sc

[0233] Example 2

[0234] A polyethylene carbonate resin composition was prepared by performing the same method as in Example 1, except that 0.05 parts by weight of citric acid was added based on 100 parts by weight of the solid content of the polyalkylene carbonate in Example 1. In this case, the residual catalyst component in the composition had the same level as in Example 1.

[0235] Example 3

[0236] A polyethylene carbonate resin composition was prepared by performing the same method as in Example 1, except that 0.1 parts by weight of citric acid was added based on 100 parts by weight of the solid content of the polyalkylene carbonate in Example 1. In this case, the residual catalyst component in the composition had the same level as in Example 1.

[0237] Example 4

[0238] A polyethylene carbonate resin composition was prepared by performing the same method as in Example 1, except that 0.3 parts by weight of citric acid was added based on 100 parts by weight of the solid content of the polyalkylene carbonate in Example 1. In this case, the residual catalyst component in the composition had the same level as in Example 1.

[0239] Example 5

[0240] A polyethylene carbonate resin composition was prepared by performing the same method as in Example 1, except that 0.01 parts by weight of tartaric acid was added instead of citric acid based on 100 parts by weight of the solid content of the polyalkylene carbonate in Example 1. In this case, the residual catalyst component in the composition had the same level as in Example 1.

[0241] Example 6

[0242] A polyethylene carbonate resin composition was prepared by performing the same method as in Example 1, except that 0.002 parts by weight of maleic acid was added instead of citric acid based on 100 parts by weight of the solid content of the polyalkylene carbonate in Example 1. In this case, the residual catalyst component in the composition had the same level as in Example 1.

[0243] Example 7

[0244] A polyethylene carbonate resin composition was prepared by performing the same method as in Example 1, except that 0.004 parts by weight of ascorbic acid was added instead of citric acid based on 100 parts by weight of the solid content of the polyalkylene carbonate in Example 1. In this case, the residual catalyst component in the composition had the same level as in Example 1.

[0245] Comparative Example 1

[0246] A polyethylene carbonate resin composition was prepared by performing the same method as in Example 1, except that citric acid was not added in Example 1. In this case, the level of the catalyst component remaining in the composition was the same as that in Example 1.

[0247] Comparative Example 2

[0248] A polyethylene carbonate resin composition was prepared by performing the same method as in Example 1, except that 0.76 parts by weight of citric acid was added based on 100 parts by weight of the solid content of the polyalkylene carbonate in Example 1. In this case, the residual catalyst component in the composition had the same level as in Example 1.

[0249] Comparative Example 3

[0250] A polyethylene carbonate resin composition was prepared by performing the same method as in Example 1, except that 0.5 parts by weight of citric acid was added based on 100 parts by weight of the solid content of the polyalkylene carbonate in Example 1. In this case, the residual catalyst component in the composition had the same level as in Example 1.

[0251] Comparative Example 4

[0252] A polyethylene carbonate resin composition was prepared by performing the same method as in Example 6, except that 0.0005 parts by weight of maleic acid was added based on 100 parts by weight of the solid content of the polyalkylene carbonate in Example 6. In this case, the residual catalyst component in the composition had the same level as in Example 1.

[0253] Comparative Example 5

[0254] 10 mg of the double metal cyanide catalyst prepared in the preparation example, 20 g of ethylene oxide and 10 g of dioxolane solvent were added to a high-pressure reactor. Then, carbon dioxide was injected into the reactor and a pressure of 30 bar was applied. The polymerization reaction was carried out at 70 ° C for 24 hours. After the reaction was completed, the unreacted carbon dioxide was removed to obtain a polymer containing polyalkylene carbonate. The product was then diluted in a dioxolane solvent to a solid content of polyalkylene carbonate in the polymer of 20% by weight, and passed through a 0.2 μm filter to remove the catalyst. The resultant was poured onto a tray and dried in a vacuum oven at 40 ° C for 6 hours to obtain a polyethylene carbonate resin composition. In this case, the residual catalyst components in the composition were Co <1 ppm and Zn <2 ppm.

[0255] Experimental example

[0256] The molecular weight performance and thermal stability of the polyalkylene carbonate compositions prepared in the examples and comparative examples were compared and analyzed. The results are shown in Tables 1 and Figure 1 middle.

[0257] (1) Molecular weight performance

[0258] Molecular weight properties were analyzed by gel permeation chromatography (GPC) using polystyrene as a standard material.

[0259] Column: Two Agilent PLgel MIXED-B columns (7.5 mm x 300, 10 μm)

[0260] Solvent: Chloroform

[0261] Flow rate: 0.7 ml / min

[0262] Column temperature: 40°C

[0263] Sample: 4.0 mg / 1.0 ml chloroform

[0264] Sample injection volume: 20 μl

[0265] Standard material: Polystyrene

[0266] Furthermore, the molecular weight properties were measured before and after the heat treatment of the polyalkylene carbonate composition, and the molecular weight change rate was also confirmed according to the following Mathematical Equation 2.

[0267] [Mathematical equation 2]

[0268] Molecular weight change rate (%) = (|Mw1-Mw2| / Mw1) × 100

[0269] In mathematical equation 2,

[0270] Mw1 is the weight average molecular weight of the polyalkylene carbonate resin composition measured by gel chromatography before heat treatment, and Mw2 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.

[0271] (2) Thermal stability

[0272] Thermal stability was confirmed by mass change analysis using a thermogravimetric analyzer (TGA) and a mass change rate (mass loss rate) according to the following mathematical equation 1.

[0273] [Mathematical equation 1]

[0274] Mass change rate (%) = (|W1-W2| / W1) × 100

[0275] In mathematical equation 1,

[0276] W1 is the mass of the polyalkylene carbonate resin composition at 0 minutes in a 60-minute 200° C. isothermal step in mass change analysis using a thermogravimetric analyzer, and W2 is the mass of the polyalkylene carbonate resin composition at 60 minutes in a 60-minute 200° C. isothermal step.

[0277] Specifically, mass change analysis was performed using a thermogravimetric analyzer (TGA2, Mettler Toledo) according to the following procedure.

[0278] 1) Step 1: Temperature rises from 30°C to 50°C (10°C / min)

[0279] 2) Step 2: Heat at 150°C for 5 minutes

[0280] 3) Step 3: Temperature rises from 150°C to 200°C (10°C / min)

[0281] 4) Step 4: Incubate at 200°C for 60 minutes

[0282] [Table 1]

[0283]

[0284] As shown in Table 1, the polyethylene carbonate resin compositions of Examples 1 to 7 were confirmed to have a molecular weight change rate of 55% or less, a mass change rate of 10% or less, and significantly reduced decomposition by heat treatment compared to the comparative examples.

[0285] Specifically, compared with the polyethylene carbonate resin composition of Comparative Example 1 which does not contain an organic acid, for the polyethylene carbonate resin compositions of Examples 1 to 7, the molecular weight change rate is reduced to a level of about 56% to 79%, and the mass change rate is reduced to a level of about 1% to 7%, and the molecular weight and mass changes caused by heat treatment are significantly reduced, thereby confirming that by including an organic acid in the polyalkylene carbonate resin composition according to the present invention, the residual catalyst component is deactivated, and the thermal decomposition caused by the catalyst component is suppressed, thereby significantly improving the thermal stability.

[0286] Furthermore, in Comparative Examples 2 and 3, where the organic acid was contained but exceeded the upper limit of the suitable range specified in the present invention, resulting in excessive organic acid content and an excessively high weight ratio of the organic acid to the residual catalyst component, the molecular weight change rates were 62% and 58%, respectively, and the inhibitory effect on thermal decomposition of the polymer chain was reduced. In Comparative Example 4, where the organic acid content was below the lower limit of the suitable range, the molecular weight change rate was 61% and the mass change rate was 38%, indicating that the inhibitory effect on thermal decomposition was not significant. This confirms that when an organic acid is contained but the content deviates from the range specified in the present invention, thermal decomposition is accelerated or the catalyst deactivation effect is not achieved.

[0287] In addition, in the case of the polyethylene carbonate resin composition of Comparative Example 5 prepared by including a catalyst removal step, although the residual catalyst component in the composition was significantly reduced compared to the Examples, the mass change rate was about 4 to 21 times higher than that of the Examples. It can be found that the polyalkylene carbonate resin composition containing a specific amount of organic acid according to the present invention has excellent thermal stability through a more economical process.

Claims

1. A polyalkylene carbonate resin composition comprising: a polyalkylene carbonate; and an organic acid, wherein: The organic acid is included in an amount of 0.001 parts by weight to less than 0.5 parts by weight based on 100 parts by weight of the polyalkylene carbonate.

2. The polyalkylene carbonate resin composition according to claim 1, wherein The organic acid is included in an amount of 0.05 to 0.1 parts by weight based on 100 parts by weight of the polyalkylene carbonate.

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

00.

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

6. The polyalkylene carbonate resin composition according to claim 3, wherein 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 formula 1: The metal salt is represented by the following formula 2: [Formula 1] Y a M`(CN) b In formula 1, M' is at least one selected from 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, b is an integer from 4 to 6, and the values ​​of a and b are selected so that the metal cyanide complex becomes electrically neutral, [Formula 2] M(X) n In 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 one selected from the group consisting of halides, hydroxides, sulfates, carbonates, cyanates, oxalates, thiocyanates, isocyanates, isothiocyanates, carboxylates, and nitrates, n is a number that satisfies the valence of M.

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. The polyalkylene carbonate resin composition according to claim 6, wherein The metal salt is at least one selected from zinc (II) chloride, zinc (III) chloride, 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 equation 1 is less than 10%: [Mathematical equation 1] Mass change rate (%) = (|W1-W2| / W1) × 100 In mathematical equation 1, W1 is the mass of the polyalkylene carbonate resin composition at 0 minutes in a 60-minute 200°C isothermal step in mass change analysis using a thermogravimetric analyzer, and W2 is the mass of the polyalkylene resin composition at 60 minutes in a 60-minute 200°C isothermal step.

10. The polyalkylene carbonate resin composition according to claim 1, wherein The molecular weight change rate defined by the following mathematical equation 2 is 55% or less: [Mathematical equation 2] Molecular weight change rate (%) = (|Mw1-Mw2| / Mw1) × 100 In mathematical equation 2, Mw1 is the weight average molecular weight of the polyalkylene carbonate resin composition measured by gel chromatography before heat treatment, and Mw2 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 includes a repeating unit represented by the following Formula 3 and a repeating unit represented by the following Formula 4: [Formula 3] [Formula 4] In Equation 3 and Equation 4, R1 to R8 are each independently hydrogen, a linear alkyl group of 1 to 20 carbon atoms, a branched alkyl group of 3 to 20 carbon atoms, an aryl group of 6 to 20 carbon atoms, an alkenyl group of 2 to 20 carbon atoms, or a cycloalkyl group of 3 to 20 carbon atoms, * indicates the connecting part between repeating units, x and y are mole fractions, where x is from 0.70 to 1.00, y is from 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. 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, polypentylene carbonate, polyhexylene carbonate, polyoctylene carbonate, and polycyclohexylene carbonate.

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

15. A method for preparing a polyalkylene carbonate resin composition, the method comprising: a step of polymerizing an alkylene oxide compound with carbon dioxide in a solvent in the presence of a catalyst to prepare a polymer comprising polyalkylene carbonate; adding an organic acid to the polymer and stirring; and The step of removing the solvent, wherein The organic acid is added in an amount of 0.001 parts by weight to less than 0.5 parts by weight based on 100 parts by weight of the solid content of the polyalkylene carbonate in the polymer.

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

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

18. The method for preparing a polyalkylene carbonate resin composition according to claim 15, wherein: The polymerization is carried out at a temperature ranging from 30°C to 120°C.

19. The method for preparing a polyalkylene carbonate resin composition according to claim 15, wherein: The complexing agent is at least one selected from the group consisting of cyclobutanol, cyclopentanol, cyclohexanol, cycloheptanol, cyclooctanol, 1-methylcyclopentanol, 2-methylcyclopentanol, 3-methylcyclopentanol, 1-ethylcyclopentanol, 2-ethylcyclopentanol, 3-ethylcyclopentanol, 1-propylcyclopentanol, 2-propylcyclopentanol, 3-propylcyclopentanol, 1-butylcyclopentanol, 2-butylcyclopentanol, 3-butylcyclopentanol, 1-isopropylcyclopentanol, 2-isopropylcyclopentanol, 3-isopropylcyclopentanol, 1-(prop-2-yl)cyclopentanol, 2,2-dimethylcyclopentanol, 2,3-dimethylcyclopentanol, 3,3-dimethylcyclopentanol, 1,2-dimethylcyclopentanol, 1,3-dimethylcyclopentanol, 1-methylcyclohexanol, 1-ethylcyclohexanol, 1-propylcyclohexanol, 1-butylcyclohexanol Alcohol, 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, 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-cyclohexanol, 3,4-dimethyl-1-cyclohexanol, 1-methylcycloheptanol, 2-methylcycloheptanol, 3-methylcycloheptanol and 4-methylcycloheptanol.

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