Polyester resin composition and method for predicting properties thereof

Abstract

The present invention provides a polyester resin composition comprising a copolymer containing a furan dicarboxylic acid-based compound-derived residue and an alkylene glycol-based compound-derived residue, wherein the polyester resin composition comprises 20,000 ppm or less of impurities, which are 2-formyl-5-furan dicarboxylic acid, relative to the total weight of the furan dicarboxylic acid-based compound and has 20 or less in the b* value according to the CIE1976 L*a*b* color system. The present invention also provides a method for predicting properties of a polyester resin composition, the method comprising a step of measuring the content of impurities, which are 2-formyl-5-furan dicarboxylic acid contained in a furan dicarboxylic acid-based compound, wherein the polyester resin composition comprises a copolymer containing a furan dicarboxylic acid-based compound-derived residue and an alkylene glycol-based compound-derived residue. Therefore, a polyester resin allowing for a short polymerization reaction time and having improved viscosity and color can be produced, and the properties of a synthesized polyester resin can be predicted by the measurement of impurities in raw materials.

Description

Polyester resin composition and method for predicting physical properties thereof

[0001] It relates to a polyester resin composition and a method for predicting its physical properties.

[0002] Polyester resin refers to a polymer resin with an ester (RO-C(=O)-R') functional group in the main chain, and is used for various purposes such as packaging, display, and insulating materials in various industrial fields. A representative example is polyethylene terephthalate (PET) resin, which is manufactured by the reaction of terephthalic acid (TPA) and ethylene glycol (EG). However, the main raw material of terephthalic acid is paraxylene, which is manufactured by refining crude oil, so the manufacture and use of terephthalic acid causes depletion of crude oil resources. Furthermore, when terephthalic acid decomposes, carbon dioxide emissions increase, causing environmental pollution and contributing to climate change such as global warming.

[0003] In this regard, efforts are ongoing to replace terephthalic acid with 2,5-furan dicarboxylic acid (FDCA) in the production of polyester resins. FDCA, a biomass-derived material, can prevent the depletion of crude oil resources and, due to its biodegradability, minimize environmental pollution and climate change.

[0004] However, research is still needed on methods to improve the properties of polyester manufactured by the reaction of 2,5-furan dicarboxylic acid and ethylene glycol and to predict the properties.

[0005] The purpose of the present invention is to provide a method for predicting the physical properties of a polyester resin composition and a polyester resin having improved physical properties through the method.

[0006] In one embodiment, a polyester resin composition comprising a copolymer including a residue derived from a furan dicarboxylic acid-based compound; and a residue derived from an alkylene glycol-based compound; wherein the polyester resin composition includes an impurity of 2-formyl-5-furandicarboxylic acid in an amount of 20,000 ppm or less based on the total weight of the furan dicarboxylic acid-based compound, and the polyester resin composition has a b* value of 20 or less according to the CIE1976 L*a*b* colorimetric system.

[0007] The above polyester resin composition may further contain metal impurities in an amount of 200 ppm or less based on the total weight of the furan dicarboxylic acid compound.

[0008] The above metal impurity may be one or more selected from the group consisting of Fe, Mg, and Na.

[0009] The above furan dicarboxylic acid compound may be 2,5-furandicarboxylic acid.

[0010] After heat-treating the above furan dicarboxylic acid compound, the furan dicarboxylic acid compound may have a transmittance of 30% or more when dissolved in a basic solvent and measured using a UV spectrophotometer.

[0011] After dissolving the above furan dicarboxylic acid compound in ammonia water and filtering it through a filter paper, the color difference compared to the blank test filter paper measured using a spectrophotometer may be 20 or less.

[0012] After dissolving the above furan dicarboxylic acid compound in a basic solvent, the alkaline transmittance of the furan dicarboxylic acid compound measured using a UV spectrophotometer may be 70% or more.

[0013] The above polyester resin composition may have an intrinsic viscosity of 0.5 dl / g to 0.7 dl / g as measured using an Oswald viscometer at 25°C.

[0014] In another embodiment, a method for producing a polyester resin composition is provided, comprising the steps of: (i) subjecting a mixture comprising a furan dicarboxylic acid-based compound and an alkylene glycol-based compound to an esterification reaction; (ii) subjecting the esterification reaction product to a prepolymerization reaction; and (iii) subjecting the prepolymerized polymer to a polycondensation reaction; wherein the polyester resin composition contains an impurity of 2-formyl-5-furandicarboxylic acid in an amount of 20,000 ppm or less based on the total weight of the furan dicarboxylic acid-based compound, and the polyester resin composition has a b* value of 20 or less according to the CIE1976 L*a*b* colorimetric system.

[0015] In another embodiment, a method for predicting the properties of a polyester resin composition is provided, comprising the step of measuring the content of an impurity, 2-formyl-5-furandicarboxylic acid, contained in a furan dicarboxylic acid-based compound; wherein the polyester resin composition comprises a copolymer including a residue derived from a furan dicarboxylic acid-based compound; and a residue derived from an alkylene glycol-based compound.

[0016] The method may further include a step of measuring the content of an impurity, 2-formyl-5-furandicarboxylic acid, contained in the furan dicarboxylic acid compound; and a step of measuring the content of a metal impurity contained in the furan dicarboxylic acid compound.

[0017] The above metal impurity may be one or more selected from the group consisting of Fe, Mg, and Na.

[0018] The method may further include a step of measuring the content of an impurity, 2-formyl-5-furandicarboxylic acid, contained in the furan dicarboxylic acid compound; and a step of heat-treating the furan dicarboxylic acid compound, dissolving it in a basic solvent, and measuring the transmittance.

[0019] The method may further include a step of measuring the content of impurities, which are 2-formyl-5-furandicarboxylic acid, contained in the furan dicarboxylic acid compound; and a step of dissolving the furan dicarboxylic acid compound in ammonia water, filtering the resultant, and measuring the color of the filter paper.

[0020] The method may further include a step of measuring the content of an impurity, 2-formyl-5-furandicarboxylic acid, contained in the furan dicarboxylic acid compound; and a step of dissolving the furan dicarboxylic acid compound in a basic solvent and then measuring alkaline permeability.

[0021] In one embodiment, a polyester resin having a short polymerization reaction time and improved viscosity and color can be manufactured, and the properties of the synthesized polyester resin can be predicted by measuring impurities in the raw material.

[0022] Below, specific implementation examples are described in detail to facilitate their implementation by those skilled in the art. However, the present invention may be implemented in various different forms and is not limited to the implementation examples described herein.

[0023] The terminology used herein is for the purpose of describing exemplary embodiments only and is not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

[0024] When a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise stated.

[0025] The term "moiety" as used herein refers to a certain portion or unit derived from a specific compound when the specific compound participates in a chemical reaction and is included in the product of the chemical reaction. More specifically, the "moiety" derived from a furan dicarboxylic acid compound and the "moiety" derived from an alkylene glycol compound refer to a portion derived from a furan dicarboxylic acid compound and a portion derived from an alkylene glycol compound, respectively.

[0026] The term "alkyl" as used herein, unless otherwise stated, refers to saturated monovalent aliphatic hydrocarbon radicals, including straight and branched chains, having a specific number of carbon atoms. An alkyl group typically has from 1 to 20 carbon atoms ("C1-C 20 alkyl"), preferably having 1 to 12 carbon atoms ("C1-C 12 Alkyl"), more preferably containing 1 to 8 carbon atoms ("C1-C8 alkyl"), or 1 to 6 carbon atoms ("C1-C6 alkyl"), or 1 to 4 carbon atoms ("C1-C4 alkyl"). Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, iso-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, n-heptyl, n-octyl, and the like. The alkyl group may be substituted or unsubstituted. In particular, unless otherwise specified, the alkyl group may be substituted with one or more halogens, up to the total number of hydrogen atoms present on the alkyl moiety. Thus, C1-C4 alkyl may be a halogenated alkyl group, for example, a fluorinated alkyl group having 1 to 4 carbon atoms, such as trifluoromethyl (-CF3) or difluoroethyl (-CH2CHF2). Includes.

[0027] An alkyl group described herein as optionally substituted may be substituted with one or more substituents, which substituents are independently selected unless otherwise stated. The total number of substituents is equal to the total number of hydrogen atoms on the alkyl moiety, to the extent that such substitution makes chemical sense. An optionally substituted alkyl group typically contains from 1 to 6 optional substituents, often from 1 to 5 optional substituents, preferably from 1 to 4 optional substituents, and more preferably from 1 to 3 optional substituents.

[0028] Optional substituents suitable for the above alkyl group include, but are not limited to, C1-C8 alkyl, C2-C8 alkenyl, C2-C8 alkynyl, C3-C8 cycloalkyl, 3- to 12-membered heterocyclyl, C6-C 12 Aryl and 5- to 12-membered heteroaryl, halo, =O(oxo), =S(thiono), =N-CN, =N-OR x , =NR x , -CN, -C(O)R x , -CO2R x , -C(O)NR x R y , -SR x , -SOR x , -SO2R x , -SO2NR x R y , -NO2, -NR x R y , -NR x C(O)R y , -NR x C(O)NR x R y , -NR x C(O)OR x , -NR x SO2R y , -NR x SO2NR x R y , -OR x , -OC(O)R x and -OC(O)NR x Ry , and each R x and R y is independently hydrogen (H), C1-C8 alkyl, C1-C8 acyl, C2-C8 alkenyl, C2-C8 alkynyl, C3-C8 cycloalkyl, 3- to 12-membered heterocyclyl, C6-C 12 Aryl or 5 to 12 membered heteroaryl, or R x and R y can form a 3- to 12-membered heterocyclyl or 5- to 12-membered heteroaryl ring together with the N atom to which they are attached, each optionally selected from O, N and S(O) q (wherein q is 0 to 2) may contain 1, 2 or 3 additional heteroatoms selected from; each R x and R y is optionally substituted with 1 to 3 substituents independently selected from the group consisting of halo, =O, =S, =N-CN, =N-OR', =NR', -CN, -C(O)R', -CO2R', -C(O)NR'2, -SOR', -SO2R', -SO2NR'2, -NO2, -NR'2, -NR'C(O)R', -NR'C(O)NR'2, -NR'C(O)OR', -NR'SO2R', -NR'SO2NR'2, -OR', -OC(O)R' and -OC(O)NR'2, wherein each R' is independently hydrogen (H), C1-C8 alkyl, C1-C8 acyl, C2-C8 alkenyl, C2-C8 alkynyl, C3-C8 cycloalkyl, 3- to 12-membered heterocyclyl, C6-C 12 Aryl or C5-C 12 Heteroaryl; each of the above C1-C8 alkyl, C2-C8 alkenyl, C2-C8 alkynyl, C3-C8 cycloalkyl, 3- to 12-membered heterocyclyl, C6-C 12 Aryl and 5- to 12-membered heteroaryl may be optionally substituted as further defined herein.

[0029] The term "alkoxy" as used herein, unless otherwise stated, refers to a monovalent -O-alkyl group wherein the alkyl moiety has the specified number of carbon atoms. Alkoxy groups typically have from 1 to 8 carbon atoms ("C1-C8 alkoxy"), or from 1 to 6 carbon atoms ("C1-C6 alkoxy"), or from 1 to 4 carbon atoms ("C1-C4 alkoxy"). For example, C1-C4 alkoxy includes methoxy (-OCH3), ethoxy (-OCH2CH3), isopropoxy (-OCH(CH3)2), tert-butyloxy (-OC(CH3)3), and the like. The alkoxy group is optionally substituted on the alkyl moiety by the same groups described herein as appropriate for alkyl. In particular, the alkoxy group may be optionally substituted with one or more halo atoms, particularly one or more fluoro atoms, up to the total number of hydrogen atoms present on the alkyl moiety. Such groups are referred to as "haloalkoxy" groups having a specific number of carbon atoms and substituted with one or more halo substituents, e.g., when fluorinated, more specifically as "fluoroalkoxy" groups, typically containing from 1 to 6 carbon atoms, preferably from 1 to 4 carbon atoms, often 1 or 2 carbon atoms, and 1, 2 or 3 halo atoms (i.e., "C1-C6 haloalkoxy", "C1-C4 haloalkoxy" or "C1-C2 haloalkoxy"). More specifically, fluorinated alkyl groups can be specifically referred to as fluoroalkoxy groups, typically substituted with 1, 2 or 3 fluoro atoms, e.g., C1-C6, C1-C4 or C1-C2 fluoroalkoxy groups. Therefore, C1-C4 fluoroalkoxy includes trifluoromethyloxy (-OCF3), difluoromethyloxy (-OCF2H), fluoromethyloxy (-OCFH2), difluoroethyloxy (-OCH2CF2H), etc.

[0030] As used herein, unless otherwise stated, the term "divalent aliphatic hydrocarbon (i.e., alkylene)" refers to a divalent hydrocarbyl group having a specified number of carbon atoms capable of linking two other groups together. Often, alkylene is represented by the group -(CH2) n -(wherein n is 1 to 8, preferably n is 1 to 4). If specified, alkylene may also be substituted with other groups and may include at least 1 degree of unsubstitution (i.e., an alkenylene or alkynylene moiety) or a ring. The open valencies of the alkylene need not be at opposite ends of the chain. Thus, branched alkylene groups such as -CH(Me)-, -CH2CH(Me)-, and -C(Me)2- are also included within the scope of the term "alkylene", as are cyclic groups such as cyclopropane-1,1-diyl and unsaturated groups such as ethylene (-CH=CH-) or propylene (-CH2-CH=CH-). The alkylene groups are optionally substituted by the same groups as described herein as suitable for alkyl.

[0031] As used herein, the terms "optionally substituted" and "substituted or unsubstituted" are used interchangeably to indicate that the particular group being described may have no non-hydrogen substituents (i.e., unsubstituted), or that the group may have one or more non-hydrogen substituents (i.e., substituted). Unless otherwise specified, the total number of substituents that may be present is equal to the number of H atoms present on the unsubstituted form of the group being described. When an optional substituent is attached via a double bond (e.g., an oxo (=O) substituent), that group occupies an available valence, so that the total number of other substituents included is reduced by two. When an optional substituent is independently selected from a list of alternatives, the selected groups may be the same or different. It will be understood that throughout this specification, the number and nature of optional substituents will be limited to the extent that such substitutions make chemical sense.

[0032] In this specification, the CIE1976 L*a*b* color space corresponds to a color space that is currently standardized worldwide, as defined by the CIE (International Commission on Illumination). In this CIE 1976 L*a*b* color space, the L* value represents brightness in color coordinates, and the range is 0 to 100, with 0 representing complete black and 100 representing complete white. a* represents whether it leans toward red or green. If this value is positive, that is, "+", it is red; if it is negative, that is, "-", it is green. b* represents whether it leans toward yellow or blue. If this value is positive, that is, "+", it is yellow; and if it is negative, that is, "-", it is blue.

[0033] Based on the above definitions, implementation examples of the present invention will be described in detail. However, these are presented as examples and are not intended to limit the present invention. The present invention is defined solely by the scope of the claims set forth below.

[0034]

[0035] polyester resin composition

[0036] In one embodiment, a polyester resin composition comprising a copolymer including a residue derived from a furan dicarboxylic acid-based compound; and a residue derived from an alkylene glycol-based compound; wherein the polyester resin composition includes an impurity of 2-formyl-5-furandicarboxylic acid in an amount of 20,000 ppm or less based on the total weight of the furan dicarboxylic acid-based compound, and the polyester resin composition has a b* value of 20 or less according to the CIE1976 L*a*b* colorimetric system.

[0037] A copolymer included in a polyester resin composition according to one embodiment can be manufactured through a series of processes in which a furan dicarboxylic acid compound and an alkylene glycol compound are subjected to an esterification reaction, a preliminary polymerization reaction, and a polycondensation reaction.

[0038] Furan dicarboxylic acid compounds are derived from eco-friendly raw materials manufactured from biomass such as wood and corn, and can be completely decomposed (biodegraded) by microorganisms under certain conditions. Therefore, using furan dicarboxylic acid compounds instead of terephthalic acid as the raw material for copolymers can prevent the depletion of crude oil resources. In addition, copolymers manufactured using furan dicarboxylic acid compounds as raw materials exhibit biodegradability, which can contribute to preventing environmental pollution, climate change, etc. However, furan dicarboxylic acid compounds have low thermal stability, and copolymers manufactured using them generally exhibit low brightness due to yellowing or browning. However, a copolymer according to one embodiment can exhibit relatively high brightness because yellowing or browning is suppressed, even though it is manufactured using a furan dicarboxylic acid compound as a raw material.

[0039] Furan dicarboxylic acid compounds

[0040] The above copolymer contains a residue derived from a furan dicarboxylic acid compound (hereinafter referred to as “furan dicarboxylic acid compound-derived residue”) and exhibits excellent biodegradability due to the furan dicarboxylic acid compound.

[0041] The above furan dicarboxylic acid compound can be represented by the following chemical formula 1:

[0042] [Chemical Formula 1]

[0043]

[0044] In the above chemical formula 1, L1 and L2 are each independently a single bond or a substituted or unsubstituted alkylene having 1 to 10 carbon atoms.

[0045] For example, the furan dicarboxylic acid compound may be 2,5-furandicarboxylic acid, in which case both L1 and L2 in the chemical formula 1 may be single bonds.

[0046] The above furan dicarboxylic acid compound-derived residue can be represented by the following chemical formula 1-1:

[0047] [Chemical Formula 1-1]

[0048]

[0049] In the above chemical formula 1-1, L1 and L2 are each independently a single bond, or a substituted or unsubstituted alkylene having 1 to 10 carbon atoms; * indicates a bonding position.

[0050] For example, when the furan dicarboxylic acid compound is 2,5-furandicarboxylic acid, both L1 and L2 in the chemical formula 1-1 may be single bonds.

[0051] The polyester resin composition including the copolymer including the residue derived from the furan dicarboxylic acid compound may include an impurity that is 2-formyl-furan-5-carboxylic acid (FFCA), and more specifically, the impurity that is 2-formyl-5-furan dicarboxylic acid may be included in the furan dicarboxylic acid compound. Here, the impurity that is 2-formyl-5-furan dicarboxylic acid may be included in the polyester resin composition in an amount of 20,000 ppm or less based on the total weight of the furan dicarboxylic acid compound, for example, 10,000 ppm or less, 5,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 100 ppm or less, and may be included in an amount of 0 ppm or more, or 10 ppm or more. The content of the impurity, which is the 2-formyl-5-furandicarboxylic acid, can be measured through a liquid chromatogram (HPLC) or 1H-NMR. More specifically, the liquid chromatogram can be analyzed by weighing the furan dicarboxylic acid compound with a direct viewing balance and passing it through a Hector-M C18 column at a UV analysis wavelength of 280 nm. In addition, 1H-NMR can be analyzed by dissolving the furan dicarboxylic acid compound in a solvent and performing the analysis under the conditions of Nuclide 1H, lock solvent DMSO-d6, scan 128, RD 4 sec, X offset 5 ppm, X sweep 15 ppm, and acquisition point 32768. When the impurity, which is the 2-formyl-5-furandicarboxylic acid, is included within the above range, there is an advantage in that the color of the polymerized copolymer can be improved by minimizing the amount of the impurity.

[0052] In one embodiment, the polyester resin composition may further include a metal impurity, and more specifically, the furan dicarboxylic acid compound may further include a metal impurity. The metal impurity may be at least one selected from the group consisting of Ca, Ce, Cr, Cu, Fe, Mg, Mn, Mo, Na, Nb, Sn, Sr, Ti, V, W, Zn, and Zr, and more specifically, may be at least one selected from the group consisting of Fe, Mg, and Na. Here, the content of the metal impurity with respect to the total weight of the furan dicarboxylic acid compound may be included at 200 ppm or less, for example, 100 ppm or less, 70 ppm or less, 60 ppm or less, or 50 ppm or less, and may be included at 0 ppm or more, or 10 ppm or more. The content of the above metal impurities can be measured through ICP-MS, and more specifically, furan dicarboxylic acid can be dissolved in a solvent and measured under the conditions of Replicates 3, Sweep 50, Reading 1, and Vacuum Pressure 3.3E-7 Torr. When the content of the metal impurities is within the above range, there is an advantage of improving the color of the polymerized copolymer by minimizing the amount of impurities. When the content of the metal impurities is not within the above range, the esterification reaction, which is the first step in the polymerization process, does not proceed, and thus the polymerization reaction, which is the next step, does not proceed. If the raw material is continuously heated in the reactor without the reaction proceeding, there is a problem that the raw material is carbonized.

[0053] In one embodiment, after heat-treating the furan dicarboxylic acid compound, the furan dicarboxylic acid compound may have a transmittance of 30% or more when dissolved in a basic solvent and measured using a UV spectrophotometer, and may be, for example, 30% to 99%, 32% to 98%, 34% to 96%, 36% to 94%, 38% to 92%, or 40% to 90%. When the transmittance of the furan dicarboxylic acid compound is within the above range, there is an advantage of increasing the heat resistance of the polymerized copolymer.

[0054] In one embodiment, the color difference between the furan dicarboxylic acid compound dissolved in ammonia water and the solution filtered and measured using a spectrophotometer and the blank filter paper may be 20 or less, for example, 1 to 20, 0.8 to 18, 0.6 to 16, 0.1 to 14, or 0.1 to 12. More specifically, the solution of the furan dicarboxylic acid compound dissolved in ammonia water is filtered through a filter paper, the filter paper is dried, the color Y (Y1) is measured using a spectrophotometer, and the color Y (Y2) difference △Y (△Y=Y2-Y1) with the blank filter paper (filter paper dried under the same conditions after filtering with ammonia water) can be measured. When the color difference of the furan dicarboxylic acid compound is within the above range, there is an advantage in that heat denaturation of yellowing or browning of the polymerized copolymer is suppressed.

[0055] In one embodiment, after dissolving the furan dicarboxylic acid compound in a basic solvent, the alkaline permeability of the furan dicarboxylic acid compound measured using a UV spectrophotometer may be 70% or more, for example, 70% to 99%, 72% to 99%, 74% to 99%, 76% to 99%, 78% to 99%, or 80% to 99%. When the alkaline permeability of the furan dicarboxylic acid compound is within the above range, the mechanical properties and heat resistance of the polymerized copolymer may be further improved.

[0056] alkylene glycol compounds

[0057] The above copolymer contains a residue derived from an alkylene glycol compound (hereinafter, “alkylene glycol compound-derived residue”), and exhibits excellent compatibility and elongation properties due to the residue derived from the alkylene glycol compound.

[0058] The above alkylene glycol compound can be represented by the following chemical formula 2:

[0059] [Chemical Formula 2]

[0060]

[0061] In the above chemical formula 2, L3 and L4 are each independently substituted or unsubstituted C 1-10 It is alkylene.

[0062] For example, the alkylene glycol compound may be ethylene glycol. In this case, L3 in the chemical formula 2 may be C1 alkylene (i.e., methylene), and R4 may be C1 alkylene (i.e., methylene).

[0063] The residue derived from the above alkylene glycol compound can be represented by the following chemical formula 2-1:

[0064] [Chemical Formula 2-1]

[0065]

[0066] In the above chemical formula 2-1, R3 and R4 are each independently substituted or unsubstituted C 1-10 It is alkylene; * indicates the bonding position.

[0067] For example, when the alkylene glycol compound is ethylene glycol, R3 in the chemical formula 2-1 may be C1 alkylene (i.e., methylene), and R4 may be C1 alkylene (i.e., methylene).

[0068] The molar ratio of the furan dicarboxylic acid-based compound-derived residue and the alkylene glycol-based compound-derived residue in the copolymer may be 9:1 to 1:9, 8:2 to 2:8, or 1:1 to 1:2. In this range, the effects of the furan dicarboxylic acid-based compound-derived residue and the alkylene glycol-based compound-derived residue can be harmoniously implemented.

[0069] The above copolymer may be a random copolymer or a block copolymer, which is a block copolymer. Specifically, the copolymer does not contain additional residues and may be represented by the following chemical formula 3:

[0070] [Chemical Formula 3]

[0071]

[0072] In the above chemical formula 3, the definition of each substituent is as described above.

[0073] For example, the copolymer may be represented by the following chemical formula 3-1:

[0074] [Chemical Formula 3-1]

[0075]

[0076] Specifically, the copolymer represented by the above chemical formula 3-1 corresponds to poly(ethylene furandicarboxylate) (PEF) in which the furan dicarboxylic acid-based compound-derived residue is a furan dicarboxylic acid-derived residue, the ethylene glycol-based compound-derived residue is an ethylene glycol-derived residue, and the molar ratio of the ethylene glycol-derived residue and the ethylene glycol-derived residue is 1:1.

[0077] polyester resin composition

[0078] The above polyester resin composition has a b* value of 20 or less according to the CIE1976 L*a*b* colorimetric system. The color characteristics according to the CIE1976 L*a*b* colorimetric system may be measured using a chip colorimetric system. Specifically, the polyester resin composition may be measured using a colorimetric system according to the CIE1976 L*a*b* colorimetric system without being pretreated.

[0079] The higher the L* value, the closer to white the color can be. However, depending on the use, purpose, etc. of the product to which the polyester resin composition according to one embodiment is applied, the brightness can be controlled within a range of 93 or more, 94 or more, or 95 or more, and 100 or less, 99 or less, or 98 or less.

[0080] The lower the a* value, the lighter the red and the darker the green. However, depending on the use, purpose, etc. of the product to which the polyester resin composition according to one embodiment is applied, the a* value may be 0 or more, 0.1 or more, 0.3 or more, 0.5 or more, or 0.7 or more, and 2 or less, 1.8 or less, 1.7 or less, 1.5 or less, or 1.4 or less, so that the degree of red and green can be controlled.

[0081] The lower the b* value, the lighter the yellow and the darker the blue. In particular, according to the evaluation examples described below, all comparative examples have b* values ​​exceeding 20, while all examples have b* values ​​of 20 or less, indicating that thermal discoloration such as yellowing and browning is suppressed during the manufacturing process. However, depending on the use, purpose, etc. of the product to which the polyester resin composition according to one embodiment is applied, the degree of yellow and blue can be controlled in a range where the b* value is 20 or less, 19 or less, 18 or less, 17 or less, or 16 or less, and 0 or more, 1 or more, 2 or more, 3 or more, or 4 or more.

[0082] According to one embodiment, the polyester resin composition may have an intrinsic viscosity at 25°C of 0.1 dl / g to 1.0 dl / g, for example, 0.2 dl / g to 0.9 dl / g, 0.3 dl / g to 0.8 dl / g, or 0.5 dl / g to 0.7 dl / g. The intrinsic viscosity of the polyester resin composition may be measured by heating and melting the polyester resin composition, using an Ostwald viscometer, measuring the time required to pass through a certain capillary length, and calculating the viscosity through the calibration formula (time (seconds) + 52.077) / 211.23). When the intrinsic viscosity of the polyester resin composition satisfies the above range, the problem of high viscosity that may lower productivity can be solved, and at the same time, there is an advantage of easy film processing.

[0083] The polyester resin composition may have a number average molecular weight (Mn) of 20,000 g / mol or more, 21,000 g / mol or more, 22,000 g / mol or more, 23,000 g / mol or more, 24,000 g / mol or more, or 25,000 g / mol or more, and 30,000 g / mol or less, 29,000 g / mol or less, or 27,000 g / mol or less. When the number average molecular weight of the polyester resin composition satisfies the above range, not only is it easy to process into a film for use as a packaging material, but it also has the advantage of being able to increase productivity and yield due to an appropriate viscosity.

[0084] The polyester resin composition may have a molecular weight distribution (MWD), i.e., a ratio of weight average molecular weight (Mw) / number average molecular weight (Mn), of 1 or more, 1.2 or more, 1.4 or more, or 1.5 or more, and 2.5 or less, 2 or less, 1.9 or less, or 1.8 or less. When the molecular weight distribution of the polyester resin composition satisfies the above range, not only process control becomes easier, but also there is an advantage of being able to reduce the defect rate of the product due to the uniform molecular weight distribution.

[0085] According to one embodiment, a polyester resin composition may have a glass transition temperature (Tg) of 70°C to 110°C, for example, 75°C to 100°C, or 77°C to 90°C. When the glass transition temperature of the polyester resin composition satisfies the above range, it has the advantages of having thermal stability at room temperature, being easy to process into a film, and being able to suppress a decrease in transparency.

[0086] Method for producing a polyester resin composition

[0087] In another embodiment, a method for producing a polyester resin composition is provided, comprising: a step of esterifying a mixture comprising a furan dicarboxylic acid-based compound and an alkylene glycol-based compound; a step of prepolymerizing the esterification reaction product; and a step of polycondensing the prepolymerized polymer; wherein the polyester resin composition contains an impurity of 2-formyl-5-furandicarboxylic acid in an amount of 20,000 ppm or less based on the total weight of the furan dicarboxylic acid-based compound, and the polyester resin composition has a b* value of 20 or less according to the CIE1976 L*a*b* colorimetric system.

[0088] Hereinafter, descriptions that overlap with the above contents will be omitted, and each step of the above manufacturing method will be described in detail.

[0089] esterification reaction

[0090] In a method for manufacturing a polyester resin composition according to one embodiment, a mixture including a furan dicarboxylic acid compound and an alkylene glycol compound is subjected to an esterification reaction. In this step, an oligomer having a low degree of polymerization can be formed.

[0091] The mixture in the esterification reaction step may contain 100 to 200 moles of the alkylene glycol compound based on 100 moles of the furan dicarboxylic acid compound. When the contents of the furan dicarboxylic acid compound and the alkylene glycol compound are within the above range, the viscosity increase rate in the condensation reaction can be increased, the color of the polymer can be improved, and the Clear point can be confirmed, so there is an advantage in that the end point of the esterification reaction can be confirmed.

[0092] Meanwhile, considering the amount of material that is lost or unreacted during the esterification reaction, the alkylene glycol compound may be used in an excess of about 120% based on the furan dicarboxylic acid compound. Accordingly, by adjusting the molar ratio of the reactants within the above range, a copolymer in which the content of each residue is controlled within the above range may be formed. More specifically, based on 100 mol of the furan dicarboxylic acid compound, the alkylene glycol compound may be included in an amount of 100 mol or more, 110 mol or more, 115 mol or more, or 120 mol or more, and 200 mol or less, 190 mol or less, 180 mol or less, or 150 mol or less.

[0093] The esterification reaction may be performed under a nitrogen (N2) atmosphere, a temperature range of 180 to 220°C, and a pressure of 1 to 5.5 atm for 1 to 5 hours. For example, the esterification reaction may be performed at a temperature range of 180°C or higher, 182°C or higher, 184°C or higher, or 185°C or higher, and 220°C or lower, 210°C or lower, 200°C or lower, or 195°C or lower. In addition, the esterification reaction may be performed at 1 atm or higher, 5.5 atm or lower, 5 atm or lower, 3 atm or lower, or 1.5 atm or lower, and may be performed for 1 hour or longer, 1.5 hours or longer, or 2 hours or longer, and 5 hours or shorter, 4 hours or shorter, or 3 hours or shorter. When the temperature, pressure, reaction time, etc. of the above esterification reaction are within the above range, the reaction yield is high, the reaction proceeds sufficiently, and the properties of the final polyester manufactured are improved, while the possibility of the appearance of the manufactured polyester turning yellow is reduced, which has the advantage of being advantageous.

[0094] The above esterification exchange reaction can be performed in a batch or continuous manner, and each raw material can be introduced separately, but as an example, it can be introduced in the form of a slurry in which the alkylene glycol is mixed with a furan-based dicarboxylic acid.

[0095] The above esterification reaction may be carried out in the presence of an esterification reaction catalyst including a titanium (Ti)-based compound, a tin (Sn)-based compound, an antimony (Sb)-based compound, or the like. In particular, the esterification reaction catalyst can improve the reaction rate from the beginning of the reaction and shorten the time that the polyester resin composition is exposed to heat. The esterification reaction catalyst can be used in an amount of 1 ppm to 100 ppm based on the central atom in the synthesized polyester. When the content of the esterification reaction catalyst is within the above range, there is an advantage in that the appearance properties of the manufactured polyester can be improved and the efficiency of the esterification reaction can be greatly improved.

[0096] Prepolymerization

[0097] In a method for producing a polyester resin composition according to one embodiment, the esterification reaction product is pre-polymerized to produce an oligomer having a higher degree of polymerization than the esterification reaction product. More specifically, water is generated during the reaction process of the furan dicarboxylic acid compound and the alkylene glycol compound, and the esterification reaction is completed when the furan dicarboxylic acid compound completely melts and reaches the Clear point.

[0098] The above prepolymerization may be performed under temperature-controlled conditions. More specifically, the prepolymerization may be performed including a step of increasing the temperature until it reaches a temperature range of 220 to 280°C or 220 to 260°C; and a step of maintaining the temperature and prepolymerizing the esterification reaction product. In addition, during the temperature increase, the pressure may be reduced until it reaches 0 to 1 atm or 0 to 0.5 atm, and the reached pressure may also be maintained while maintaining the reached temperature. When the reached temperature, reached pressure, reaction time, etc. during the prepolymerization are within the above-described ranges, sufficient reaction occurs, thereby improving the properties of the final polyester and reducing the possibility of yellowing.

[0099] polycondensation

[0100] In a method for producing a polyester resin composition according to one embodiment, after the prepolymerization, the prepolymerized polymer is subjected to a polycondensation reaction.

[0101] The above polycondensation reaction can be carried out at a temperature range of 220 to 280°C or 220 to 260°C; and under a pressure of 1 torr or less or 0.4 to 0.8 torr or less, for 2 to 6 hours. When the temperature, pressure, reaction time, etc. during the polycondensation are within the above ranges, there is an advantage in that glycol, a by-product of the polycondensation reaction, is effectively removed, so that the final reaction product exhibits an appropriate intrinsic viscosity, and the appearance of the polyester produced is less likely to turn yellow.

[0102] During the above condensation, a polycondensation reaction catalyst may be used. The polycondensation catalyst may be added to the product of the esterification reaction before the initiation of the polycondensation reaction, may be added before the esterification reaction, or may be added during the esterification reaction step. The polycondensation catalyst may be a titanium-based compound, a germanium-based compound, an antimony-based compound, an aluminum-based compound, a tin-based compound, or a mixture thereof. Examples of the titanium compounds include tetraethyl titanate, acetyltripropyl titanate, tetrapropyl titanate, tetrabutyl titanate, polybutyl titanate, 2-ethylhexyl titanate, octylene glycol titanate, lactate titanate, triethanolamine titanate, acetylacetonate titanate, ethyl acetoacetic ester titanate, isostearyl titanate, titanium dioxide, titanium dioxide / silicon dioxide copolymer, titanium dioxide / zirconium dioxide copolymer, etc. Examples of the germanium compounds include germanium dioxide (GeO2), germanium tetrachloride (GeCl4), germanium ethyleneglycoxide, germanium acetate, copolymers using these, mixtures thereof, etc.

[0103] Method for predicting the physical properties of polyester resin

[0104] In another embodiment, a method for predicting the properties of a polyester resin composition, comprising the step of measuring the content of an impurity, 2-formyl-5-furandicarboxylic acid, contained in a furan dicarboxylic acid-based compound; wherein the polyester resin composition comprises a copolymer including a residue derived from a furan dicarboxylic acid-based compound; and a residue derived from an alkylene glycol-based compound; is provided.

[0105] In order to improve the physical properties of the polyester resin composition described above, the content of impurities in the furan dicarboxylic acid compound can be measured, and the physical properties of the polymerized polyester resin composition can be predicted by measuring the content of impurities in the furan dicarboxylic acid compound.

[0106] In one embodiment, the method for predicting the physical properties of the polyester resin composition includes a step of measuring the content of an impurity, 2-formyl-5-furandicarboxylic acid, contained in a furan dicarboxylic acid-based compound, wherein 2-formyl-5-furandicarboxylic acid may be contained in an amount of 20,000 ppm or less based on the total weight of the furan dicarboxylic acid-based compound, for example, 10,000 ppm or less, 5,000 ppm or less, 1,000 ppm or less, 500 ppm or less, or 100 ppm or less, and may be contained in an amount of 0 ppm or more, or 10 ppm or more. The content of the impurity, 2-formyl-5-furandicarboxylic acid, may be measured through high performance liquid chromatography (HPLC) or 1H-NMR. More specifically, the liquid chromatography (HPLC) can be performed by weighing the furan dicarboxylic acid compound with a direct viewing balance and passing it through a Hector-M C18 column to analyze it at a UV analysis wavelength of 280 nm. In addition, the 1H-NMR can be performed by dissolving the furan dicarboxylic acid compound in a solvent and analyzing it under the conditions of Nuclide 1H, lock solvent DMSO-d6, scan 128, RD 4 sec, X offset 5 ppm, X sweep 15 ppm, and acquisition point 32768. When 2-formyl-5-furandicarboxylic acid is included in the furan dicarboxylic acid compound within the above range, a polymerization reaction can proceed, and at this time, the polymerization reaction can be performed for 1 to 4 hours, for example, 2 to 3 hours, to produce a polyester resin composition. If the content of 2-formyl-5-furandicarboxylic acid impurity in the furan dicarboxylic acid compound is 20,000 ppm or more, polymerization reaction may not occur.

[0107] In one embodiment, a method for predicting physical properties of a polyester resin composition may further include, after the step of measuring the content of an impurity that is 2-formyl-5-furandicarboxylic acid contained in the furan dicarboxylic acid compound, a step of measuring a content of a metal impurity contained in the furan dicarboxylic acid compound, wherein the metal may be at least one selected from the group consisting of Ca, Ce, Cr, Cu, Fe, Mg, Mn, Mo, Na, Nb, Sn, Sr, Ti, V, W, Zn, and Zr, and more specifically, at least one selected from the group consisting of Fe, Mg, and Na. Here, the content of the metal impurity may be included at 200 ppm or less, for example, 100 ppm or less, 70 ppm or less, 60 ppm or less, or 50 ppm or less, and may be included at 0 ppm or more, or 10 ppm or more. The content of metal impurities in the polyester resin composition can be measured through ICP-MS, and more specifically, furan dicarboxylic acid is dissolved in a solvent, and the measurement can be performed under the conditions of Replicates 3, Sweep 50, Reading 1, and Vacuum Pressure 3.3E-7 Torr. When the content of metal impurities in the furan dicarboxylic acid compound is within the above range, a polymerization reaction can proceed, and at this time, the polymerization reaction can be performed for 1 to 4 hours, for example, 2 to 3 hours, to produce a polyester resin composition. When the content of metal impurities is not within the above range, the esterification reaction, which is the first step in the polymerization process, does not proceed, and thus the polymerization reaction, which is the next step, does not proceed. If the raw material is continuously exposed to heat in the reactor without the reaction proceeding, there is a problem that the raw material is carbonized.

[0108] In one embodiment, a method for predicting the properties of a polyester resin composition may further include the steps of: measuring the content of an impurity, 2-formyl-5-furandicarboxylic acid, contained in the furan dicarboxylic acid compound; and then, heat-treating the furan dicarboxylic acid compound and dissolving it in a basic solvent to measure transmittance. Here, the transmittance of the furan dicarboxylic acid compound measured using a UV spectrophotometer may be 30% or more, and may be, for example, 30% to 99%, 32% to 98%, 34% to 96%, 36% to 94%, 38% to 92%, or 40% to 90%. When the transmittance is within the above range, a polymerization reaction can proceed, and at this time, the polymerization reaction time can be 1 to 4 hours, for example, 2 to 3 hours, to produce a polyester resin composition.

[0109] In one embodiment, a method for predicting the properties of a polyester resin composition may further include the steps of: measuring the content of an impurity, 2-formyl-5-furandicarboxylic acid, contained in the furan dicarboxylic acid-based compound; and thereafter, dissolving the furan dicarboxylic acid-based compound in ammonia water, filtering the resultant, and measuring the color of a filter paper. More specifically, a solution in which the furan dicarboxylic acid-based compound is dissolved in ammonia water is filtered through a filter paper, the filter paper is dried, and the color Y (Y1) is measured using a spectrophotometer, and the difference △Y (△Y=Y2-Y1) in the color Y (Y2) of a blank filter paper (filter paper dried under the same conditions after filtering with ammonia water) may be measured. At this time, the color difference may be 20 or less, for example, 1 to 20, 0.8 to 18, 0.6 to 16, 0.1 to 14, or 0.1 to 12. When the color difference is within the above range, a polymerization reaction can proceed, and at this time, the polymerization reaction time can be 1 to 4 hours, for example, 2 to 3 hours, to produce a polyester resin composition.

[0110] In one embodiment, a method for predicting the properties of a polyester resin composition may further include the steps of: measuring the content of an impurity, 2-formyl-5-furandicarboxylic acid, contained in the furan dicarboxylic acid-based compound; and then dissolving the furan dicarboxylic acid-based compound in a basic solvent, and then measuring alkali permeability. Here, the alkali permeability may be 70% or more, and may be, for example, 70% to 99%, 72% to 99%, 74% to 99%, 76% to 99%, 78% to 99%, or 80% to 99%. When the alkali permeability is within the above range, a polymerization reaction may proceed, and at this time, the polymerization reaction may be performed for 1 hour to 4 hours, for example, 2 hours to 3 hours, to produce a polyester resin composition.

[0111] In conclusion, before proceeding with a polymerization reaction, the content of impurities contained in the furan dicarboxylic acid compound, which is a raw material, is measured, and the physical properties of the finally polymerized polyester resin composition, such as polymerization reaction time, viscosity, and color, can be predicted through the measured content of impurities.

[0112] Hereinafter, examples and comparative examples of the present invention are described. The following examples are merely illustrative of the present invention, and the present invention is not limited to the following examples.

[0113] Example 1

[0114] 2.7 mol of 2,5-furandicarboxylic acid (FDCA) and 3.4 mol of ethylene glycol (EG) were charged into a 1 L autoclave reactor, and the esterification reaction of FDCA and EG was performed at 190°C in a nitrogen atmosphere for 2 hours. The FDCA was measured to contain 80 ppm of 2-formyl-5-furandicarboxylic acid (FFCA) as an impurity, and 13.3 ppm of Fe and 43.5 ppm of Na as metal impurities.

[0115] The content of FFCA impurities in FDCA was measured using high-performance liquid chromatography (HPLC) or 1H-NMR. First, FDCA (0.1±0.005) g and methanol (10 g) were weighed using a direct reading balance, placed in a vial, mixed at a concentration of 1 wt%, and passed through a Hector-M C18 column (5 μm, 4.6 x 250 mm) for analysis. At this time, a 20 mM aqueous solution of ammonium acetate (80 vol%) and acetonitrile (20 vol%) were used as the mobile phase, flowing at a flow rate of 0.7 mL / min. Quantitative analysis was performed under UV analysis at a wavelength of 280 nm.

[0116] 1H-NMR analysis (equipment name: JEOL FT-NMR JNM-ECZ400SL1) was prepared by dissolving 100 mg of FDCA in 1 mL of dimethyl sulfoxide-d6 (DMSO-d6) solvent. Analysis was performed under the following conditions: Nuclide 1H, lock solvent DMSO-d6, scan 128, RD 4 s, X offset 5 ppm, X sweep 15 ppm, and acquisition point 32768.

[0117] The content of metal impurities in FDCA was measured using ICP-MS (equipment name: ICP-MS 7900, Agilent). Sample preparation conditions were as follows: 50-fold dilution using NMP (N-Methyl-2-Pyrrolidone) solvent, and measurement was performed under the following conditions: Replicates 3, Sweep 50, Reading 1, Vacuum pressure 3.3E-7 Torr.

[0118] After the esterification reaction is completed, titanium tert-butoxide, a type of titanium catalyst, is added as a polycondensation catalyst, and triethyl phosphonoacetate is added as a heat stabilizer. After the polycondensation catalyst and heat stabilizer are added, stirring is performed for 30 minutes, and the temperature inside the reactor is increased for 1 hour to reach 260°C, and at the same time, the pressure is gradually reduced using a vacuum pump for 1 hour to reach a vacuum state inside the reactor, thereby carrying out preliminary polymerization.

[0119] Next, the reaction is carried out for 2 to 6 hours in a vacuum state of 0.8 torr or less at a temperature of 260℃, and when the load transmitted to the torque meter of the autoclave reaches the desired load, drying is performed to obtain a polyester resin.

[0120] Examples 2 to 3 and Comparative Examples 1 to 2

[0121] In the production of the polyester resin of Example 1, the polyester resin was produced in substantially the same manner as Example 1, except that the content of FFCA impurities and metal impurities in FDCA was changed as shown in Table 1 below.

[0122] FFCA content in FDCA (ppm)Metal impurity content in FDCA (ppm)Total metal impurity content in FDCA (ppm)Example 180Fe 13.3 / Na 43.556.8Example 250Na 15.315.3Example 330Fe 12.112.1Comparative Example 10Na 330 / Mg 0.7330.7Comparative Example 230,200Mg 5252

[0123] Evaluation Example 1: FDCA Property Evaluation

[0124] The heat resistance, color change, and alkaline transmittance of the raw material FDCA were measured. First, FDCA was exposed to heat, then dissolved in a basic solvent, and the transmittance was measured to measure the heat resistance, and the results are shown in Table 2 below. 9 g of FDCA was weighed and heated in a block heater at 250°C for 3 hours to measure the heat stability of FDCA. 7.5 g of the heat-treated FDCA was dissolved in 50 mL of a 2 N KOH alkaline solution at room temperature, and the transmittance was measured at a wavelength of 400 nm using a UV spectrophotometer.

[0125] Next, FDCA was dissolved in ammonia water, filtered, and the color of the filter paper was measured, and the results are shown in Table 2 below. 20 g of FDCA was weighed, dissolved in 250 mL of 2.8 wt% ammonia water, and the solution was filtered through a filter paper (model name: Whatman GF / C, diameter 47 mm, 0.45 μm). The filter paper was dried at 60°C for 1 hour using a hot air dryer, and the color Y (Y1) was measured using a spectrophotometer (model name: NIPPON DENSHOKU SE6000). The difference in color Y (Y2) with that of a blank filter paper (filter paper dried under the same conditions after filtering ammonia water) △Y (△Y=Y2-Y1) was measured.

[0126] In addition, the alkaline transmittance was measured by dissolving FDCA in a basic solvent and measuring the transmittance, and the results are shown in Table 2 below. 7.5 g of FDCA was weighed and dissolved in 50 mL of 2N KOH alkaline solvent at room temperature, and the transmittance was measured at a wavelength of 340 nm using a UV spectrophotometer.

[0127] Heat resistance evaluation (transmittance, %) Color change (△Y) Alkali transmittance (transmittance, %) Example 144.33.697.3 Example 281.11.891.2 Example 385.94.597.4 Comparative example 118.029.459.2 Comparative example 20.349.98.7

[0128] Referring to Table 2, in the case of Comparative Example 2, in which the FFCA impurity content in FDCA is 20,000 ppm or more, it can be confirmed that the heat resistance and alkaline permeability are reduced and the color change is increased compared to Examples 1 to 3 and Comparative Example 1, in which the FFCA impurity content is 20,000 ppm or less.

[0129] In addition, in the case of Examples 2 and 3, in which the total metal impurity content is 50 ppm or less, it can be confirmed that the heat resistance and alkaline permeability are improved and color change is suppressed compared to Example 1 or Comparative Example 1, in which the total metal impurity content is 50 ppm or more.

[0130] Evaluation Example 2: Evaluation of physical properties of polyester resin

[0131] FFCA impurities and metal impurities in the polyester resins manufactured in Examples 1 to 3 and Comparative Examples 1 to 2 were measured, and the results are shown in Table 3 below.

[0132] The content of FFCA impurities in polyester resin was measured through 1H-NMR analysis (equipment name: JEOL FT-NMR JNM-ECZ400SL1). 40 mg of polyester resin composition was prepared by dissolving it in 0.7 mL of solvent (mixed solvent of 50 wt% trifluoroacetic acid and 50 wt% chloroform-d). Analysis was performed under the conditions of Nuclide 1H, lock solvent Chloroform-d, scan 128, RD 4 sec, X offset 5 ppm, X sweep 15 ppm, and acquisition point 32768.

[0133] The content of metal impurities in polyester resin was measured using ICP-MS (equipment name: ICP-MS 7900, Agilent). The polyester resin composition was diluted 50-fold using a mixed acid solution of HNO3 / HCl and prepared by microwave treatment at 180°C for 15 minutes, and measured under the conditions of 3 replicates, 50 sweeps, 1 reading, and vacuum pressure 3.3E-7 Torr.

[0134] FFCA content in polyester resin (ppm)Metal impurity content in polyester resin (ppm)Total metal impurity content in polyester resin (ppm)Example 180Fe 13.5 / Na 4457.5Example 250Na 1515Example 330Fe 1212Comparative Example 1Not AnalyzableNot AnalyzableNot AnalyzableComparative Example 2Not AnalyzableNot AnalyzableNot Analyzable

[0135] Next, the viscosity and color of the polyester resin were measured, and the results are shown in Table 4 below. The intrinsic viscosity was measured using an Ostwald viscometer. 0.5 g of the polyester resin composition was dissolved in 10 mL of a mixed solvent of 50 vol% phenol and 50 vol% 1,1,2,2-tetrachloroethane by heating to 70°C, and the viscosity was measured using an Ostwald viscometer. Once the polyester resin composition solution was prepared, the viscosity was measured after 15 minutes of stabilization in a constant temperature water bath at 25°C. The viscosity was calculated by measuring the time to pass through a certain capillary length, and the viscosity was calculated using the calibration formula (time (seconds) + 52.077) / 211.23). At this time, the calibration formula can be established by measuring the viscosity and time using a standard sample PET of a certain viscosity.

[0136] The color of the polyester resin was measured using a chip colorimeter according to the color characteristics of the CIE1976 L*a*b* colorimetric system. The polyester resin composition was measured without pretreatment using a colorimeter (model name: NIPPON DENSHOKU SE6000) according to the CIE1976 L*a*b* colorimetric system.

[0137] Polymerization reaction timeIntrinsic viscosity (IV)Color (b*)Example 12 hours 40 minutes0.6113.91Example 22 hours 50 minutes0.6313.60Example 32 hours 20 minutes0.6013.19Comparative Example 1Not polymerizedNot polymerizedNot analysisNot comparison Example 2Not polymerizedNot polymerizedNot analysisNot analysis

[0138] Referring to Table 4, Examples 1 to 3 exhibited polymerization reactions, with polymerization reactions occurring within a short time of less than 3 hours. Furthermore, the viscosity was approximately 0.6, indicating an appropriate viscosity, and the color was also 20 or less, indicating an appropriate color.

[0139] In contrast, in the case of Comparative Example 1, the content of metal impurities is 100 ppm or more compared to Examples 1 to 3. In this case, the esterification reaction, which is the first step in the polymerization process, does not proceed, and thus the polymerization reaction, which is the next step, does not proceed. If the heat is continuously applied in the reactor without the reaction proceeding, the raw material carbonizes, and it can be confirmed that the viscosity or color cannot be measured due to this. In addition, in the case of Comparative Example 2, there is a difference in the content of FFCA compared to Examples 1 to 3, and it can be confirmed that, as in Comparative Example 1, the polymerization reaction does not proceed, and thus the viscosity or color cannot be measured.

[0140] Although the preferred embodiments have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concepts defined in the following claims also fall within the scope of the present invention.

Claims

1. A residue derived from a furan dicarboxylic acid compound; and A polyester resin composition comprising a copolymer comprising a residue derived from an alkylene glycol compound; The polyester resin composition contains an impurity of 2-formyl-5-furandicarboxylic acid in an amount of 20,000 ppm or less based on the total weight of the furan dicarboxylic acid compound. A polyester resin composition having a b* value of 20 or less according to the CIE1976 L*a*b* colorimetric system of the polyester resin composition.

2. In paragraph 1, A polyester resin composition further comprising metal impurities in an amount of 200 ppm or less based on the total weight of the furan dicarboxylic acid compound.

3. In paragraph 2, A polyester resin composition wherein the metal impurity comprises at least one selected from the group consisting of Fe, Mg, and Na.

4. In paragraph 1, A polyester resin composition wherein the above furan dicarboxylic acid compound is 2,5-furandicarboxylic acid.

5. In paragraph 1, A polyester resin composition having a transmittance of a furan dicarboxylic acid compound of 30% or more, as measured using a UV spectrophotometer by dissolving the furan dicarboxylic acid compound in a basic solvent after heat-treating the compound.

6. In paragraph 1, A polyester resin composition having a color difference of 20 or less compared to a blank test filter paper measured using a spectrophotometer after dissolving the above furan dicarboxylic acid compound in ammonia water and filtering it through a filter paper.

7. In paragraph 1, A polyester resin composition having an alkaline transmittance of 70% or more of a furan dicarboxylic acid compound as measured using a UV spectrophotometer after dissolving the furan dicarboxylic acid compound in a basic solvent.

8. In paragraph 1, The above polyester resin composition is a polyester resin composition having an inherent viscosity of 0.5 dl / g to 0.7 dl / g as measured using an Oswald viscometer at 25°C. 9.(i) A step of subjecting a mixture containing a furan dicarboxylic acid compound and an alkylene glycol compound to an esterification reaction; (ⅱ) a step of pre-polymerizing the above esterification reaction product; and (iii) a method for producing a polyester resin composition, comprising the step of subjecting the pre-polymerized polymer to a polycondensation reaction; The polyester resin composition contains an impurity of 2-formyl-5-furandicarboxylic acid in an amount of 20,000 ppm or less based on the total weight of the furan dicarboxylic acid compound. A method for producing a polyester resin composition having a b* value of 20 or less according to the CIE1976 L*a*b* colorimetric system of the polyester resin composition.

10. A method for predicting the properties of a polyester resin composition, comprising: a step of measuring the content of an impurity, 2-formyl-5-furandicarboxylic acid, contained in a furan dicarboxylic acid compound; The above polyester resin composition is a method for predicting the physical properties of a polyester resin composition including a copolymer including a residue derived from a furan dicarboxylic acid compound; and a residue derived from an alkylene glycol compound.

11. In paragraph 10, A method for predicting physical properties of a polyester resin composition, further comprising: a step of measuring an impurity content of 2-formyl-5-furandicarboxylic acid contained in the furan dicarboxylic acid compound; and a step of measuring a metal impurity content contained in the furan dicarboxylic acid compound thereafter.

12. In paragraph 11, A method for predicting the properties of a polyester resin composition, wherein the metal impurity is at least one selected from the group consisting of Fe, Mg, and Na.

13. In paragraph 10, A method for predicting physical properties of a polyester resin composition, further comprising: a step of measuring an impurity content of 2-formyl-5-furandicarboxylic acid contained in the furan dicarboxylic acid compound; and a step of heat-treating the furan dicarboxylic acid compound, dissolving it in a basic solvent, and measuring the transmittance.

14. In paragraph 10, A method for predicting physical properties of a polyester resin composition, further comprising: a step of measuring an impurity content of 2-formyl-5-furandicarboxylic acid contained in the furan dicarboxylic acid compound; and a step of dissolving the furan dicarboxylic acid compound in aqueous ammonia, filtering the resultant, and measuring the color of filter paper.

15. In paragraph 10, A method for predicting physical properties of a polyester resin composition, further comprising: a step of measuring an impurity content of 2-formyl-5-furandicarboxylic acid contained in the furan dicarboxylic acid compound; and a step of dissolving the furan dicarboxylic acid compound in a basic solvent and then measuring alkali permeability.

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