Polyester resin and preparation method therefor

Abstract

Provided is a polyester resin comprising a repeating unit represented by chemical formula 1 and a repeating unit represented by chemical formula 2. [Chemical Formula 1] [Formula I] [Chemical Formula 2] [Formula II] In chemical formula 1 and chemical formula 2, L1 and L2 are each independently a single bond or a substituted or unsubstituted alkylene of 1 to 10 carbon atoms, L3 and L4 are each independently a substituted or unsubstituted alkylene of 1 to 10 carbon atoms, L5 is a single bond or a substituted or unsubstituted alkylene of 1 to 10 carbon atoms, n11 is a molar ratio of the repeating unit represented by chemical formula 1, and n12 is a molar ratio of the repeating unit represented by chemical formula 2. An embodiment can provide a polyester resin which exhibits excellent biodegradability and has improved moldability by lowering crystallinity.

Description

Polyester resin and its manufacturing method

[0001] It relates to polyester resin and a method for producing the same.

[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, furan dicarboxylic acid is a compound with low thermal stability, and causes thermal discoloration such as yellowing and browning during the esterification reaction with the diol component, and this problem cannot be solved simply by reacting furan dicarboxylic acid with the diol component.

[0005] The purpose of the present invention is to provide a polyester resin that exhibits excellent biodegradability while also having improved formability by lowering crystallinity.

[0006] In one embodiment, a polyester resin is provided comprising a repeating unit represented by the following chemical formula 1 and a repeating unit represented by the following chemical formula 2.

[0007] [Chemical Formula 1]

[0008]

[0009] [Chemical Formula 2]

[0010]

[0011] In the above chemical formula 1 and the above chemical formula 2, L1 and L2 are each independently a single bond or a substituted or unsubstituted alkylene having 1 to 10 carbon atoms, L3 and L4 are each independently a substituted or unsubstituted alkylene having 1 to 10 carbon atoms, L5 is a single bond or a substituted or unsubstituted alkylene having 1 to 10 carbon atoms, and n 11 is the molar ratio of the repeating unit represented by the above chemical formula 1, and n 12 is the molar ratio of the repeating unit represented by the above chemical formula 2.

[0012] above n 11 and n 12 The molar ratio can be 1:9 to 9:1.

[0013] The repeating unit represented by the above chemical formula 1 may be a polymer of a furan dicarboxylic acid compound and an alkylene glycol compound, and the repeating unit represented by the above chemical formula 2 may be a polymer of an itaconic acid compound and an alkylene glycol compound.

[0014] The above furan dicarboxylic acid compound can be represented by the following chemical formula 3.

[0015] [Chemical Formula 3]

[0016]

[0017] In the above chemical formula 3, L1 and L2 are each independently a single bond or a substituted or unsubstituted alkylene having 1 to 10 carbon atoms.

[0018] The above furan dicarboxylic acid compound may be 2,5-furandicarboxylic acid.

[0019] The above alkylene glycol compound can be represented by the following chemical formula 4.

[0020] [Chemical Formula 4]

[0021]

[0022] In the above chemical formula 4, L3 and L4 are each independently a substituted or unsubstituted alkylene having 1 to 10 carbon atoms.

[0023] The above itaconic acid compound can be represented by the following chemical formula 5.

[0024] [Chemical Formula 5]

[0025]

[0026] In the above chemical formula 5, L5 is a single bond or a substituted or unsubstituted alkylene having 1 to 10 carbon atoms.

[0027] The above itaconic acid compound may be itaconic acid.

[0028] The above polyester resin may further include a repeating unit represented by the following chemical formula 6, a repeating unit represented by the following chemical formula 7, or both.

[0029] [Chemical Formula 6]

[0030]

[0031] [Chemical Formula 7]

[0032]

[0033] In the above chemical formula 6 and the above chemical formula 7, L1 and L2 are each independently a single bond or a substituted or unsubstituted alkylene having 1 to 10 carbon atoms, L5 is a single bond or a substituted or unsubstituted alkylene having 1 to 10 carbon atoms, and n 13 is the molar ratio of the repeating unit represented by the above chemical formula 6, and n 14is the molar ratio of the repeating unit represented by the above chemical formula 7.

[0034] above n 13 and n 14 The molar ratio can be 1:9 to 9:1.

[0035] The repeating unit represented by the above chemical formula 6 may be a polymer of a furan dicarboxylic acid compound and an alicyclic diol compound, and the repeating unit represented by the above chemical formula 7 may be a polymer of an itaconic acid compound and an alicyclic diol compound.

[0036] The above alicyclic diol compound can be represented by the following chemical formula 8.

[0037] [Chemical Formula 8]

[0038]

[0039] The molar ratio of the above furan dicarboxylic acid compound and itaconic acid compound may be 1:1 to 20:1.

[0040] The above polyester resin may have amorphous properties.

[0041] In another embodiment, a method for producing a polyester resin is provided, comprising: a step of esterifying a monomer mixture comprising a furan dicarboxylic acid compound, an alkylene glycol compound, and an itaconic acid compound; a step of prepolymerizing the esterification reaction product; and a step of polycondensing the prepolymerized polymer.

[0042] The above monomer mixture may further include an alicyclic diol compound.

[0043] In one embodiment, a polyester resin exhibiting excellent biodegradability and having improved formability by lowering crystallinity can be provided.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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 12Alkyl"), 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.

[0049] 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.

[0050] 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 R y , 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 yis 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054]

[0055] polyester resin

[0056] In one embodiment, a polyester resin is provided comprising a repeating unit represented by the following chemical formula 1 and a repeating unit represented by the following chemical formula 2.

[0057] [Chemical Formula 1]

[0058]

[0059] [Chemical Formula 2]

[0060]

[0061] In the above chemical formula 1 and the above chemical formula 2, L1 and L2 are each independently a single bond or a substituted or unsubstituted alkylene having 1 to 10 carbon atoms, L3 and L4 are each independently a substituted or unsubstituted alkylene having 1 to 10 carbon atoms, L5 is a single bond or a substituted or unsubstituted alkylene having 1 to 10 carbon atoms, and n 11 is the molar ratio of the repeating unit represented by the above chemical formula 1, and n 12 is the molar ratio of the repeating unit represented by the above chemical formula 2. For example, n 11 and n 12 can be appropriately adjusted depending on the molecular weight of the polyester resin, for example, n 11 and n 12 The molar ratio may be 1:9 to 9:1, for example, 3:7 to 7:3, 4:6 to 6:4, or 1:4 to 4:1. That is, the repeating unit represented by the above chemical formula 1 may be a polymer of a furan dicarboxylic acid-based compound and an alkylene glycol-based compound, and the repeating unit represented by the above chemical formula 2 may be a polymer of an itaconic acid-based compound and an alkylene glycol-based compound.

[0062] A polyester resin according to one embodiment can be manufactured through a series of processes for manufacturing a copolymer by subjecting a furan dicarboxylic acid compound, an alkylene glycol compound, and an itaconic acid compound to an esterification reaction, a prepolymerization reaction, and a polycondensation reaction.

[0063] The above 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 a raw material for polyester resins can prevent the depletion of crude oil resources. In addition, polyester resins manufactured using furan dicarboxylic acid compounds as raw materials exhibit biodegradability, thereby contributing to the prevention of environmental pollution, climate change, etc. However, furan dicarboxylic acid compounds have low thermal stability, and polyester resins manufactured using them typically exhibit low brightness due to yellowing or browning. However, a polyester resin according to one embodiment can exhibit relatively high brightness by suppressing yellowing or browning, even though it is manufactured using a furan dicarboxylic acid compound as a raw material.

[0064] Furan dicarboxylic acid compounds

[0065] The above polyester resin 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.

[0066] The above furan dicarboxylic acid compound can be represented by the following chemical formula 3:

[0067] [Chemical Formula 3]

[0068]

[0069] In the above chemical formula 3, L1 and L2 are each independently a single bond or a substituted or unsubstituted alkylene having 1 to 10 carbon atoms.

[0070] For example, the furan dicarboxylic acid compound may be 2,5-furandicarboxylic acid, in which case both L1 and L2 in the chemical formula 3 may be single bonds.

[0071] The above furan dicarboxylic acid compound-derived residue can be represented by the following chemical formula 3-1:

[0072] [Chemical Formula 3-1]

[0073]

[0074] In the above chemical formula 3-1, 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.

[0075] For example, when the furan dicarboxylic acid compound is 2,5-furandicarboxylic acid, both L1 and L2 in the chemical formula 3-1 may be single bonds.

[0076] alkylene glycol compounds

[0077] The above polyester resin contains a residue derived from an alkylene glycol compound (hereinafter referred to as “alkylene glycol compound-derived residue”), and exhibits excellent compatibility and elongation properties due to the residue derived from the alkylene glycol compound.

[0078] The above alkylene glycol compound can be represented by the following chemical formula 4:

[0079] [Chemical Formula 4]

[0080]

[0081] In the above chemical formula 4, L3 and L4 are each independently a substituted or unsubstituted alkylene having 1 to 10 carbon atoms.

[0082] For example, the alkylene glycol compound may be ethylene glycol. In this case, L3 in the chemical formula 4 may be a carbon 1 alkylene (i.e., methylene), and L4 may be a carbon 1 alkylene (i.e., methylene).

[0083] The residue derived from the above alkylene glycol compound can be represented by the following chemical formula 4-1:

[0084] [Chemical Formula 4-1]

[0085]

[0086] In the above chemical formula 4-1, L3 and L4 are each independently a substituted or unsubstituted alkylene having 1 to 10 carbon atoms; * indicates a bonding position.

[0087] For example, when the alkylene glycol compound is ethylene glycol, L3 in the chemical formula 4-1 may be a carbon 1 alkylene (i.e., methylene), and L4 may be a carbon 1 alkylene (i.e., methylene).

[0088] Itaconic acid compounds

[0089] The above polyester resin contains a residue derived from an itaconic acid compound (hereinafter, “itaconic acid compound-derived residue”), and has amorphous properties due to the residue derived from the itaconic acid compound, and exhibits excellent flexibility.

[0090] The above itaconic acid compound can be represented by the following chemical formula 5.

[0091] [Chemical Formula 5]

[0092]

[0093] In the above chemical formula 5, L5 is a single bond or a substituted or unsubstituted alkylene having 1 to 10 carbon atoms.

[0094] For example, the itaconic acid compound may be itaconic acid. In this case, L5 in the chemical formula 5 may be a carbon 1 alkylene (i.e., methylene).

[0095] The residue derived from the above itaconic acid compound can be represented by the following chemical formula 5-1.

[0096] [Chemical Formula 5-1]

[0097]

[0098] In the above chemical formula 5-1, L5 is a single bond or a substituted or unsubstituted alkylene having 1 to 10 carbon atoms.

[0099] For example, when the itaconic acid compound is itaconic acid, L5 in the chemical formula 5-1 may be a carbon 1 alkylene (i.e., methylene).

[0100] Alicyclic diol compounds

[0101] The above polyester resin may further include a repeating unit represented by the following chemical formula 6, a repeating unit represented by the following chemical formula 7, or both.

[0102] [Chemical Formula 6]

[0103]

[0104] [Chemical Formula 7]

[0105]

[0106] In the above chemical formula 6 and the above chemical formula 7, L1 and L2 are each independently a single bond or a substituted or unsubstituted alkylene having 1 to 10 carbon atoms, L5 is a single bond or a substituted or unsubstituted alkylene having 1 to 10 carbon atoms, and n 13 is the molar ratio of the repeating unit represented by the above chemical formula 6, and n 14 is the molar ratio of the repeating unit represented by the above chemical formula 7. For example, n 13 and n 14 can be appropriately adjusted depending on the molecular weight of the polyester resin, for example, n 13 and n 14The molar ratio may be 1:9 to 9:1, for example, 3:7 to 7:3, 4:6 to 6:4, or 1:4 to 4:1. That is, the repeating unit represented by the above chemical formula 6 may be a polymer of a furan dicarboxylic acid compound and an alicyclic diol compound, and the repeating unit represented by the above chemical formula 7 may be a polymer of an itaconic acid compound and an alicyclic diol compound.

[0107] The above polyester resin may further include a residue derived from an alicyclic diol compound (hereinafter, “alicyclic diol compound-derived residue”), and exhibits excellent thermal properties due to the residue derived from the alicyclic diol compound.

[0108] For example, the alicyclic diol compound may be at least one compound selected from the group consisting of isosorbide, spiroglycol, cyclohexanedimethanol, norbornene dimethanol, tricyclodecane dimethanol, and pentacyclopentadecanedimethanol, and more specifically, may be isosorbide ((3S,3aR,6R,6aR)-hexahydrofuro[3,2-b]furan-3,6-diol; Isosorbide), and the isosorbide may be represented by the following chemical formula 8.

[0109] [Chemical Formula 8]

[0110]

[0111] copolymer

[0112] The above polyester resin can be manufactured by subjecting a furan dicarboxylic acid compound, an alkylene glycol compound, and an itaconic acid compound to an esterification reaction, a prepolymerization reaction, and a polycondensation reaction, and can be manufactured by subjecting a furan dicarboxylic acid compound, an alkylene glycol compound, an alicyclic diol compound, and an itaconic acid compound to an esterification reaction, a prepolymerization reaction, and a polycondensation reaction.

[0113] The polyester resin may be manufactured by controlling the molar ratio of the furan dicarboxylic acid compound and the itaconic acid compound to 1:1 to 20:1, for example, 2:1 to 18:1, 3:1 to 15:1, 4:1 to 12:1, or 5:1 to 10:1. In addition, the polyester resin may be manufactured by controlling the molar ratio of the alkylene glycol compound and the alicyclic diol compound to 1:1 to 20:1, for example, 2:1 to 18:1, 3:1 to 15:1, 4:1 to 12:1, or 5:1 to 10:1. When the molar ratio of the furan dicarboxylic acid compound, the alkylene glycol compound, the alicyclic diol compound, and the itaconic acid compound is within the above range, the esterification reaction rate and the productivity of the final polyester resin can be improved, and a polyester resin having excellent thermal properties and flexibility can be produced.

[0114] The above polyester resin 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 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.

[0115] The above polyester resin 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 satisfies the above range, not only does process control become easier, but also has the advantage of reducing the defect rate of the product due to the uniform molecular weight distribution.

[0116] According to one embodiment, the polyester resin may have an intrinsic viscosity at 25°C of 0.1 dl / g to 2.0 dl / g, for example, 0.3 dl / g to 1.7 dl / g, 0.5 dl / g to 1.4 dl / g, or 0.6 dl / g to 1.0 dl / g. When the intrinsic viscosity of the polyester resin 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.

[0117] The polyester resin according to one embodiment may have amorphous properties, and in this case, it has the advantage of exhibiting a transparent color even after heat treatment at high temperatures, making molding easy.

[0118] According to one embodiment, the polyester resin may have a tensile strength at yield point of 10 MPa to 200 MPa, for example, 30 MPa to 180 MPa, 70 MPa to 150 MPa, or 100 MPa to 120 MPa. In addition, the polyester resin according to one embodiment may have a tensile elongation at break point of 10% to 30%, for example, 11% to 28%, 12% to 26%, 13% to 24%, 14% to 22%, or 15% to 20%. When the tensile strength at yield point and the tensile elongation at break point of the polyester resin are within the above ranges, the flexibility of the polyester resin is improved, which has the advantage of facilitating molding.

[0119] Method for manufacturing polyester resin

[0120] In another embodiment, a method for producing a polyester resin is provided, comprising the steps of: subjecting a monomer mixture comprising a furan dicarboxylic acid compound, an alkylene glycol compound, and an itaconic acid compound to an esterification reaction; prepolymerizing the esterification reaction product; and subjecting the prepolymerized polymer to a polycondensation reaction. The monomer mixture may further include an alicyclic diol compound.

[0121] Hereinafter, descriptions that overlap with the above contents will be omitted, and each step of the above manufacturing method will be described in detail.

[0122] esterification reaction

[0123] In a method for manufacturing a polyester resin composition according to one embodiment, a monomer mixture including a furan dicarboxylic acid-based compound, an alkylene glycol-based compound, and an itaconic acid-based compound is subjected to an esterification reaction. The monomer mixture may further include an alicyclic diol-based compound. In this step, an oligomer having a low degree of polymerization may be formed.

[0124] The monomer mixture in the esterification reaction step may include a molar ratio of the furan dicarboxylic acid compound and the itaconic acid compound of 1:1 to 20:1, for example, 2:1 to 18:1, 3:1 to 15:1, 4:1 to 12:1, or 5:1 to 10:1. In addition, the molar ratio of the alkylene glycol compound and the alicyclic diol compound may include a molar ratio of 1:1 to 20:1, for example, 2:1 to 18:1, 3:1 to 15:1, 4:1 to 12:1, or 5:1 to 10:1. When the molar ratio of the furan dicarboxylic acid compound, the alkylene glycol compound, the alicyclic diol compound, and the itaconic acid compound is within the above range, the esterification reaction rate and the productivity of the final polyester resin can be improved, and a polyester resin having excellent thermal properties and flexibility can be produced.

[0125] 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 bar 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 bar or higher, 5.5 bar or lower, 5 bar or lower, 3 bar or lower, or 1.5 bar 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.

[0126] 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.

[0127] 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.

[0128] Prepolymerization

[0129] 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.

[0130] The above pre-polymerization can be performed under temperature-controlled conditions (thermal pre-condensation). More specifically, the pre-polymerization can be performed including the steps of: raising the temperature until it reaches a temperature range of 220 to 280°C or 220 to 260°C; and maintaining the temperature while pre-polymerizing the esterification reaction product. In addition, during the temperature increase, the pressure can be reduced until it reaches 0 to 1 bar or 0 to 0.5 bar, and then the reached pressure can also be maintained while maintaining the reached temperature. When the reached temperature, reached pressure, reaction time, etc. during the pre-polymerization are within the above-described ranges, sufficient reaction occurs, thereby improving the properties of the final polyester and reducing the possibility of yellowing.

[0131] polycondensation reaction

[0132] 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.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] Example 1

[0137] 2.4 mol of 2,5-furandicarboxylic acid (FDCA), 4.3 mol of ethylene glycol (EG), and 0.3 mol of itaconic acid (propylenedicarboxylic acid) are added to a 1 L autoclave reactor, and an esterification reaction is performed at 190°C in a nitrogen atmosphere for 3 hours.

[0138] After the esterification reaction is completed, titanium tert-butoxide, a type of titanium-based catalyst, is added as a polycondensation catalyst. After adding the polycondensation catalyst, stirring is performed for 30 minutes, the temperature inside the reactor is increased for 1 hour to reach 260°C, and then 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.

[0139] Next, the reaction is carried out for 1 to 6 hours in a vacuum state of 0.8 torr or less at a temperature of 230℃, and when the load transmitted to the torque meter of the autoclave reaches the desired load, the polyester resin is discharged and cooled to obtain the polyester resin.

[0140] Example 2

[0141] In the production of a polyester resin according to Example 1, a polyester resin was produced in substantially the same manner as in Example 1, except that 0.4 mol of isosorbide ((3S,3aR,6R,6aR)-hexahydrofuro[3,2-b]furan-3,6-diol; Isosorbide) was additionally added to a 1 L autoclave reactor.

[0142] Comparative Example 1

[0143] In the production of a polyester resin according to Example 1, a polyester resin was produced in substantially the same manner as in Example 1, except that itaconic acid was not added.

[0144] Comparative Example 2

[0145] In the production of a polyester resin according to Example 1, a polyester resin was produced in substantially the same manner as in Example 1, except that 0.4 mol of isosorbide ((3S,3aR,6R,6aR)-hexahydrofuro[3,2-b]furan-3,6-diol; Isosorbide) was additionally added instead of itaconic acid.

[0146] Evaluation Example 1: Evaluation of physical properties of polyester resin

[0147] For each of the above polyester resins, the physical properties were evaluated using the following method, and the results are shown in Table 1 below.

[0148] 1) Intrinsic viscosity (IV): 0.5 g of polyester resin sample was dissolved in 10 ml of a 1:1 (v:v) solution of Phenol:Tetrachloroethane, and IV was measured at 25 ℃ using an Ostwald viscometer.

[0149] 2) Thermal properties: Using a differential scanning calorimeter (Perkin Elmer), heat the polyester resin to 350°C at a heating rate of 20°C / min, and then cool it to 20°C. After 1 minute, heat it to 350°C at a rate of 5°C / min, and observe the peak change of the polyester resin. At this time, the crystallinity is determined based on the presence or absence of a melting point (Melting temperature, Tm). In the case of a crystalline polyester resin, a melting point is observed, and in the case of an amorphous polyester resin, a melting point is not observed.

[0150] 3) Tensile strength and tensile elongation: For polyester resin, ASTM D638-V type specimens are prepared using a microcompounder extruder at an extrusion temperature of 250 ℃ and a screw speed of 100 rpm. The polyester resin specimens prepared as described above are mounted in the LD direction using vice grips under a universal testing machine UTM 5566A (Instron). The strength at the maximum load point of the sample before fracture while elongating at a rate of 5 mm / min at room temperature is defined as the tensile strength, and the increased length at the point where the sample fractures is expressed as the tensile elongation.

[0151] Polymerization timeIntrinsic viscosity (IV)Thermal propertiesTensile strength (MPa)Tensile elongation (%)Example 11h 20min0.71Amorphous109.218.2Example 21h 12min0.66Amorphous109.817.3Comparative example 11h 40min0.59Crystalline98.58.9Comparative example 22h 46min0.55Amorphous69.710.2

[0152] Referring to Table 1, in comparison with Comparative Example 1 in which only 2,5-furandicarboxylic acid and ethylene glycol were reacted in the production of a polyester resin, or Comparative Example 2 in which 2,5-furandicarboxylic acid, ethylene glycol, and isosorbide were reacted, Examples 1 and 2 containing 2,5-furandicarboxylic acid, ethylene glycol, and itaconic acid have high intrinsic viscosity and high tensile strength and tensile elongation, confirming that the polyester resin has excellent formability. In addition, in comparison with Comparative Example 1, which has an opaque color after heat treatment at high temperature, Examples 1 and 2 containing 2,5-furandicarboxylic acid, ethylene glycol, and itaconic acid exhibit amorphousness, confirming that the polyester resin has excellent formability. Additionally, in the case of Example 2, which includes all of 2,5-furandicarboxylic acid, ethylene glycol, itaconic acid, and isosorbide, it can be confirmed that the polymerization rate is accelerated and the polymerization time is shortened compared to the case where neither itaconic acid nor isosorbide is included or only one of them is included.

[0153] 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 polyester resin comprising a repeating unit represented by the following chemical formula 1 and a repeating unit represented by the following chemical formula 2: [Chemical Formula 1] [Chemical formula 2] In the above chemical formula 1 and the above chemical formula 2, L1 and L2 are each independently a single bond or a substituted or unsubstituted alkylene having 1 to 10 carbon atoms, L3 and L4 are each independently a substituted or unsubstituted alkylene having 1 to 10 carbon atoms, L5 is a single bond, or a substituted or unsubstituted alkylene having 1 to 10 carbon atoms, n 11 is the molar ratio of the repeating unit represented by the chemical formula 1 above, n 12 is the molar ratio of the repeating unit represented by the chemical formula 2 above.

2. In paragraph 1, above n 11 and n 12 A polyester resin having a molar ratio of 1:9 to 9:

1.

3. In paragraph 1, The repeating unit represented by the above chemical formula 1 is a polymer of a furan dicarboxylic acid compound and an alkylene glycol compound, A polyester resin in which the repeating unit represented by the chemical formula 2 above is a polymer of an itaconic acid compound and an alkylene glycol compound.

4. In paragraph 3, The above furan dicarboxylic acid compound is a polyester resin represented by the following chemical formula 3: [Chemical Formula 3] In the above chemical formula 3, L1 and L2 are each independently a single bond, or a substituted or unsubstituted alkylene having 1 to 10 carbon atoms.

5. In paragraph 3, The above furan dicarboxylic acid compound is a polyester resin which is 2,5-furandicarboxylic acid.

6. In paragraph 3, The above alkylene glycol compound is a polyester resin represented by the following chemical formula 4: [Chemical Formula 4] In the above chemical formula 4, L3 and L4 are each independently a substituted or unsubstituted alkylene having 1 to 10 carbon atoms.

7. In paragraph 3, The above itaconic acid compound is a polyester resin represented by the following chemical formula 5: [Chemical Formula 5] In the above chemical formula 5, L5 is a single bond, or a substituted or unsubstituted alkylene having 1 to 10 carbon atoms.

8. In paragraph 3, The above itaconic acid compound is a polyester resin containing itaconic acid.

9. In paragraph 1, The above polyester resin further comprises a repeating unit represented by the following chemical formula 6, a repeating unit represented by the following chemical formula 7, or both: [Chemical formula 6] [Chemical formula 7] In the above chemical formula 6 and the above chemical formula 7, L1 and L2 are each independently a single bond or a substituted or unsubstituted alkylene having 1 to 10 carbon atoms, L5 is a single bond, or a substituted or unsubstituted alkylene having 1 to 10 carbon atoms, n 13 is the molar ratio of the repeating unit represented by the chemical formula 6 above, n 14 is the molar ratio of the repeating unit represented by the chemical formula 7 above.

10. In paragraph 9, above n 13 and n 14 A polyester resin having a molar ratio of 1:9 to 9:

1.

11. In paragraph 9, The repeating unit represented by the above chemical formula 6 is a polymer of a furan dicarboxylic acid compound and an alicyclic diol compound, A polyester resin in which the repeating unit represented by the chemical formula 7 above is a polymer of an itaconic acid compound and an alicyclic diol compound.

12. In paragraph 11, The above alicyclic diol compound is a polyester resin represented by the following chemical formula 8. [Chemical formula 8] 13. In paragraph 3, A polyester resin wherein the molar ratio of the furan dicarboxylic acid compound and the itaconic acid compound is 1:1 to 20:

1.

14. In paragraph 1, The above polyester resin is a polyester resin having amorphous properties.

15. A step of esterifying a monomer mixture including a furan dicarboxylic acid compound, an alkylene glycol compound, and an itaconic acid compound; A step of pre-polymerizing the above esterification reaction product; and A method for producing a polyester resin, comprising: a step of subjecting the above-mentioned prepolymer to a polycondensation reaction.

16. In paragraph 15, A method for producing a polyester resin further comprising an alicyclic diol compound in the above monomer mixture.

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