Polyester copolymers containing recycled monomers

Abstract

The present disclosure relates to a polyester copolymer including a recycled monomer, a method of preparing the polyester copolymer, and an article including the polyester copolymer, and can provide a polyester copolymer having excellent properties while using a recycled monomer.

Description

Field of the Invention

[0001] The present invention relates to polyester copolymers comprising recycled monomers, methods for preparing the polyester copolymers, and articles comprising the polyester copolymers.

[0002] Description of Related Technology

[0003] Since polyester has excellent mechanical strength, heat resistance, transparency and gas barrier properties, it is most suitable as a material for beverage bottles, packaging films, audio devices, video films and the like, and is being used in large quantities. And, it is also widely produced worldwide as an industrial material such as medical fibers or tire cords and the like. Since polyester sheets or polyester boards have good transparency and excellent mechanical strength, they are widely used as materials for boxes, boxes, partitions, store shelves, protective panels, blister packages, building materials, interior finishing materials and the like.

[0004] Meanwhile, waste plastics, which cause about 70% of marine pollution, have recently risen to become a serious social problem, and therefore, countries are planning to recycle waste plastics while regulating disposable plastics. Methods for recycling waste plastics can be mainly divided into two methods, one is a method in which waste plastics are collected, crushed and cleaned, and then melt-extruded to be re-granulated, and used as raw materials; and the other is a method in which materials obtained by depolymerization of waste plastics are used as monomers for the synthesis of plastics. In the latter case, bis-2-hydroxyethyl terephthalate can be obtained by depolymerization of PET or PETG in waste plastics, and research on its use as a monomer of polyester copolymers is underway.

[0005] However, it is difficult to obtain satisfactory materials due to impurities in waste plastics, and in particular, plastics prepared from materials obtained by depolymerization of waste plastics often suffer from quality deterioration.

[0006] Therefore, the inventors of the present disclosure confirmed that the quality of a polyester copolymer prepared from a material obtained by depolymerization of waste plastics can be improved by using recycled bis-2-hydroxyethyl terephthalate as a monomer of the polyester copolymer and controlling the amount of the monomer as described below, and completed the present invention.

[0007] Public Content

[0008] Technical issues

[0009] An object of the present invention is to provide a polyester copolymer comprising recycled monomers, a method for preparing the polyester copolymer, and an article comprising the polyester copolymer.

[0010] Technical Solutions

[0011] To achieve the object, there is provided a polyester copolymer obtained by copolymerizing recycled bis-2-hydroxyethyl terephthalate, a dicarboxylic acid or a derivative thereof, and a diol including ethylene glycol and a comonomer, and having a structure in which a portion derived from bis-2-hydroxyethyl terephthalate, an acid portion derived from a dicarboxylic acid or a derivative thereof, and a diol portion derived from a diol are repeated,

[0012] wherein the polyester copolymer comprises from 10 wt% to 80 wt% of a moiety derived from recycled bis-2-hydroxyethyl terephthalate, and

[0013] The molar ratio of diol to dicarboxylic acid or its derivative is 0.2:1 to 1.35:1.

[0014] Definition of terms

[0015] The copolymer according to the present disclosure is prepared by copolymerization of a dicarboxylic acid or a derivative thereof and a diol including ethylene glycol and a comonomer, and during the copolymerization, recycled bis-2-hydroxyethyl terephthalate participates in the reaction.

[0016] As used herein, the term 'a portion derived from ...' means a certain portion or unit derived from a specific compound contained in a product of a chemical reaction when the specific compound participates in a chemical reaction. Specifically, an acid portion derived from a dicarboxylic acid or a derivative thereof and a diol portion derived from a diol respectively mean a repeating unit in a polyester copolymer formed by an esterification reaction or a polycondensation reaction. And, a portion derived from bis-2-hydroxyethyl terephthalate means a repeating unit in a polyester copolymer formed by an esterification reaction in a copolymerization reaction.

[0017] Dicarboxylic acid or its derivatives

[0018] The dicarboxylic acid or its derivative used in the present disclosure is the main monomer constituting the polyester copolymer together with the diol component. In particular, the dicarboxylic acid includes terephthalic acid, and therefore, the properties of the polyester copolymer according to the present disclosure, such as heat resistance, chemical resistance, weather resistance and the like, can be improved. Furthermore, the terephthalic acid residue can also be formed from alkyl terephthalate, preferably from dimethyl terephthalate.

[0019] In addition to terephthalic acid, the dicarboxylic acid component may also include an aromatic dicarboxylic acid component, an aliphatic dicarboxylic acid component or a mixture thereof. In this case, it is preferred that the dicarboxylic acid component other than terephthalic acid may be contained in an amount of 1 wt % to 30 wt % based on the total weight of all dicarboxylic acid components.

[0020] The aromatic dicarboxylic acid component may be a C8-20 aromatic dicarboxylic acid, preferably a C8-14 aromatic dicarboxylic acid or a mixture thereof, and the like. As examples of aromatic dicarboxylic acids, isophthalic acid, naphthalene dicarboxylic acids such as 2,6-naphthalene dicarboxylic acid and the like, biphenyl dicarboxylic acid, 4,4'-stilbene dicarboxylic acid, 2,5-furan dicarboxylic acid, 2,5-thiophene dicarboxylic acid and the like may be mentioned, but specific examples of aromatic dicarboxylic acids are not limited thereto. The aliphatic dicarboxylic acid component may be a C4-20 aliphatic dicarboxylic acid, preferably a C4-12 aliphatic dicarboxylic acid or a mixture thereof, and the like. As examples of aliphatic dicarboxylic acids, cyclohexanedicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid and the like, linear, branched or cyclic aliphatic dicarboxylic acids such as phthalic acid, sebacic acid, succinic acid, isodecylsuccinic acid, maleic acid, fumaric acid, adipic acid, glutaric acid, azelaic acid and the like can be mentioned, but specific examples of the aliphatic dicarboxylic acids are not limited thereto.

[0021] Diol

[0022] The diol component used in the present disclosure is a main monomer constituting a polyester copolymer together with the dicarboxylic acid or its derivatives described above. Specifically, the diol component includes ethylene glycol and a comonomer, and the comonomer includes cyclohexanedimethanol or isosorbide.

[0023] Ethylene glycol is a component that helps improve the transparency and impact strength of the polyester copolymer. Preferably, the ethylene glycol residue is contained in an amount of 5 to 100 moles based on 100 moles of the total diol component residues.

[0024] Cyclohexanedimethanol (e.g., 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol or 1,4-cyclohexanedimethanol) is a component that helps improve the transparency and impact strength of the prepared polyester copolymer. Preferably, the cyclohexanedimethanol residue is contained in an amount of 5 to 90 moles based on 100 moles of the total diol component residues.

[0025] Isosorbide is used to improve the processing properties of the prepared polyester copolymer. Although the transparency and impact strength of the polyester copolymer are improved by the diol components of cyclohexanedimethanol and ethylene glycol described above, for the sake of processing properties, the shear thinning property should be improved and the crystallization rate should be delayed, but it is difficult to achieve such effects with cyclohexanedimethanol and ethylene glycol. Therefore, in the case where isosorbide is included as the diol component, the shear thinning property can be improved and the crystallization rate can be delayed while maintaining transparency and impact strength, thereby improving the processing properties of the prepared polyester copolymer. Preferably, the isosorbide residue is included in an amount of 0.1 mol to 50 mol based on 100 mol of the total diol component residues.

[0026] Meanwhile, in the diol component used for copolymerization of the polyester copolymer according to the present disclosure, the molar ratio of the comonomer to ethylene glycol (comonomer:ethylene glycol) is preferably 0.1:1 to 20:1. Here, 'molar ratio' means the molar ratio of the components introduced during the copolymerization of the polyester copolymer. If the molar ratio is less than 0.1, the transparency and impact strength of the polyester copolymer may be reduced, and if the molar ratio is greater than 20, by-products may increase, thereby causing quality deterioration of the polyester copolymer.

[0027] Recycled bis-2-hydroxyethyl terephthalate

[0028] As used herein, the term 'recycled bis-2-hydroxyethyl terephthalate' means a material obtained from waste plastics collected after use. As waste plastics from which bis-2-hydroxyethyl terephthalate can be obtained, PET and PETG and the like can be mentioned. For example, bis-2-hydroxyethyl terephthalate can be obtained from PETG collected after use by glycolysis, hydrolysis, methanolysis and the like, and these methods are widely known in the art.

[0029] Since recycled bis-2-hydroxyethyl terephthalate undergoes many chemical steps in the process of being obtained from waste plastics, if it is used as a monomer of a copolymer, it inevitably causes product quality deterioration. In particular, if it is used as a monomer of a polyester copolymer, the color quality may deteriorate and a large amount of by-products may be generated, as described below.

[0030] Therefore, in the present disclosure, recycled bis-2-hydroxyethyl terephthalate is used as the main monomer constituting the polyester copolymer according to the present disclosure, while controlling the content so that the polyester copolymer contains 10wt% to 80wt% of recycled bis-2-hydroxyethyl terephthalate residues. If the content of recycled bis-2-hydroxyethyl terephthalate residues is less than 10wt%, the content of the diols described above is relatively increased, and thus, by-products derived from the diol component, especially by-products derived from ethylene glycol, increase, thereby causing the quality of the polyester copolymer to deteriorate. And, if the content of recycled bis-2-hydroxyethyl terephthalate residues is greater than 80wt%, the color quality and transparency of the polyester copolymer may deteriorate.

[0031] And, in order to suppress the quality deterioration of the polyester copolymer due to the use of recycled bis-2-hydroxyethyl terephthalate, in the copolymerization reaction of the polyester copolymer according to the present disclosure, the molar ratio of diol to dicarboxylic acid or its derivative is controlled to be 0.2:1 to 1.35:1. Here, 'molar ratio' means the molar ratio of the components introduced during the copolymerization of the polyester copolymer. If the molar ratio is greater than 1.35, due to the high molar ratio of diol, by-products derived from the diol component, especially by-products derived from ethylene glycol, may exceed 2wt%, and if the molar ratio is less than 0.2, the content of the recycled bis-2-hydroxyethyl terephthalate residue may be relatively increased, thereby deteriorating the color quality and transparency of the polyester copolymer.

[0032] Polyester copolymer

[0033] The polyester copolymer according to the present disclosure can be prepared by copolymerizing the recycled bis-2-hydroxyethyl terephthalate, dicarboxylic acid or its derivatives, ethylene glycol and comonomers described above, wherein the copolymerization can be carried out by sequentially performing an esterification reaction (step 1) and a polycondensation reaction (step 2).

[0034] The esterification reaction is carried out in the presence of an esterification catalyst, and an esterification catalyst comprising a zinc-based compound can be used. As specific examples of such zinc-based catalysts, zinc acetate, zinc acetate dihydrate, zinc chloride, zinc sulfate, zinc sulfide, zinc carbonate, zinc citrate, zinc gluconate or a mixture thereof can be mentioned. And, the amount of each starting material used is as described above.

[0035] Esterification reaction can be carried out at 0kg / cm 2 Up to 10.0kg / cm 2 The esterification reaction conditions can be appropriately controlled according to the specific properties of the polyester to be prepared, the ratio of each component or the process conditions and the like. Specifically, as preferred examples of the esterification reaction conditions, 0 kg / cm 2 Up to 5.0kg / cm 2 , more preferably 0.1kg / cm 2 Up to 3.0kg / cm 2 ; 200 ℃ to 270 ℃, more preferably 240 ℃ to 260 ℃ temperature.

[0036] And, the esterification reaction can be carried out batchwise or continuously, and each raw material can be introduced separately, but it is preferably introduced in the form of a slurry in which the dicarboxylic acid component and the recycled bis-2-hydroxyethyl terephthalate are mixed with the diol component. And, a diol component such as isosorbide, which is solid at room temperature, can be made into a slurry by dissolving it in water or ethylene glycol, and then mixing it with a dicarboxylic acid such as terephthalic acid. Alternatively, the slurry can be prepared by melting isosorbide at 60° C. or higher, and then mixing it with a dicarboxylic acid such as terephthalic acid and other diol components. And, water can be additionally introduced into the slurry to help improve the fluidity of the slurry.

[0037] The polycondensation reaction can be performed by reacting the esterification reaction product at a temperature of 150° C. to 300° C. and a reduced pressure of 600 mmHg to 0.01 mmHg for 1 hour to 24 hours.

[0038] Such polycondensation reaction can be carried out at a reaction temperature of 150°C to 300°C, preferably 200°C to 290°C, more preferably 260°C to 280°C; and at a pressure of 600mmHg to 0.01mmHg, preferably 200mmHg to 0.05mmHg, more preferably 100mmHg to 0.1mmHg. By applying reduced pressure conditions, ethylene glycol, a by-product of the polycondensation reaction, can be removed to the outside of the system, and therefore, if the polycondensation reaction does not meet the reduced pressure conditions of 600mmHg to 0.01mmHg, the removal of the by-products may be insufficient. Also, if the polycondensation reaction is performed outside the temperature range of 150° C. to 300° C., in the case where the polycondensation reaction is performed at less than 150° C., the by-product ethylene glycol may not be effectively removed to the outside of the system, and thus, the intrinsic viscosity of the final reaction product may be low and the properties of the prepared polyester copolymer may be deteriorated, while in the case where the reaction is performed at more than 300° C., it is more likely that the appearance of the prepared polyester copolymer may be yellowish. Also, the polycondensation reaction may be performed for a desired time, such as an average residence time of 1 hour to 24 hours, until the intrinsic viscosity of the final reaction product reaches a suitable level.

[0039] And, the polycondensation reaction may be performed using a polycondensation catalyst including a titanium-based compound, a germanium-based compound, an antimony-based compound, an aluminum-based compound, a tin-based compound, or a mixture thereof.

[0040] As examples of titanium-based compounds, tetraethyl titanate, acetyl tripropyl titanate, tetrapropyl titanate, tetrabutyl titanate, 2-ethylhexyl titanate, octanediol titanate, titanium lactate, triethanolamine titanate, titanium acetylacetonate, ethyl acetoacetate titanium, isostearyl titanate, titanium dioxide and the like can be mentioned. As examples of germanium-based compounds, germanium dioxide, germanium tetrachloride, ethylene glycol germanium, germanium acetate, copolymers using them, or mixtures thereof can be mentioned. Preferably, germanium dioxide can be used, and as such germanium dioxide, crystalline germanium dioxide or non-crystalline germanium dioxide can be used.

[0041] Meanwhile, the polyester copolymer according to the present disclosure has an intrinsic viscosity of 0.50 dl / g to 1.0 dl / g, preferably 0.50 dl / g to 0.85 dl / g, more preferably 0.55 dl / g to 0.80 dl / g. The measuring method of the intrinsic viscosity will be described in detail in the examples described below.

[0042] And, preferably, in the polyester copolymer according to the present disclosure, the content of by-products may be 2.0wt% or less, more preferably 1.5wt% or less, 1.0wt% or less, based on the weight of the polyester copolymer. By-products mean diol components other than EG (ethylene glycol) detected in the polyester copolymer. The method for measuring by-products will be described in detail in the embodiments described below.

[0043] And, preferably, the haze of the polyester copolymer according to the present disclosure may be 4 or less, more preferably 3.5 or less, 3.0 or less, 2.5 or less, 2.0 or less, 1.5 or less, or 1.0 or less. And, the theoretical lower limit value of the haze is 0, and in the present disclosure, the haze may be 0.1 or more, 0.2 or more, 0.3 or more, 0.4 or more, or 0.5 or more. The measurement method of the haze will be described in detail in the embodiments described below.

[0044] And, preferably, for a sample having a thickness of 6 mm, '(Hunter L color value)-(Huber b color value)' (hereinafter, referred to as plaque color Lb) of the polyester copolymer according to the present disclosure may be 85 or more, more preferably 86 or more, 87 or more, 88 or more, 89 or more, or 90 or more. And, the upper limit value of plaque color Lb may be 100, and in the present disclosure, it may be 99 or less, 98 or less, 97 or less, 96 or less, or 95 or less. The measuring method of plaque color Lb will be described in detail in the embodiments described below.

[0045] Also provided according to the present disclosure are articles comprising the polyester copolymers.

[0046] Beneficial Effects

[0047] The polyester copolymer according to the present disclosure described above may provide a polyester copolymer having excellent properties while using recycled monomers. DETAILED DESCRIPTION

[0048] Hereinafter, preferred embodiments will be provided to help understand the present invention. However, these embodiments are only provided for better understanding of the present invention, and the scope of the present invention is not limited thereto.

[0049] Example 1

[0050] Into a reactor having a capacity of 10 L connected to a column and a condenser capable of being cooled by water, recycled bis-2-hydroxyethyl terephthalate (1269.7 g; hereinafter referred to as 'r-BHET'), TPA (terephthalic acid; 2361.8 g), EG (ethylene glycol; 673.5 g), CHDM (1,4-cyclohexanedimethanol; 221.5 g) and ISB (isosorbide; 98.2 g) were introduced, and GeO2 (1.0 g) was introduced as a catalyst, phosphoric acid (1.46 g) was introduced as a stabilizer, and cobalt acetate (0.7 g) was introduced as a colorant.

[0051] Subsequently, nitrogen gas was introduced into the reactor to pressurize the reactor so that the pressure of the reactor was 1.0 kgf / cm higher than the atmospheric pressure. 2 (Absolute pressure: 1495.6 mmHg). And, the temperature of the reactor was raised to 220°C within 90 minutes, maintained at 220°C for 2 hours, and then raised to 260°C within 2 hours. And then, while maintaining the temperature of the reactor at 260°C and performing the esterification reaction, the mixture in the reactor was observed with the naked eye until the mixture became transparent. During this process, the by-product was discharged through the column and the condenser. After the esterification reaction was completed, the nitrogen in the pressurized reactor was discharged to the outside to reduce the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7L capable of performing a vacuum reaction.

[0052] And, the pressure of the reactor is reduced from atmospheric pressure to 5 Torr (absolute pressure: 5 mmHg) within 30 minutes, and at the same time, the temperature of the reactor is increased to 280°C within 1 hour, and the polycondensation reaction is carried out while maintaining the pressure of the reactor at 1 Torr (absolute pressure: 1 mmHg) or less. At the beginning of the polycondensation reaction, the stirring speed is set to be fast, but as the polycondensation reaction proceeds, the stirring speed can be appropriately controlled when the stirring force decreases due to the increase in the viscosity of the reactants or the temperature of the reactants increases beyond the established temperature. The polycondensation reaction is carried out until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor becomes 0.55 dl / g. If the intrinsic viscosity of the mixture in the reactor reaches the desired level, the mixture is discharged to the outside of the reactor to make a strand, which is solidified with a coolant, and then granulated so that the average weight becomes 12 mg to 14 mg.

[0053] The particles were placed at 150° C. for 1 hour for crystallization, and then introduced into a solid phase polymerization reactor having a capacity of 20 L. And then, nitrogen was flowed into the reactor at a rate of 50 L / min. Wherein, the temperature of the reactor was increased from room temperature to 140° C. at a rate of 40° C. / hour, maintained at 140° C. for 3 hours, and then increased to 200° C. at a rate of 40° C. / hour, and maintained at 200° C. Solid phase polymerization was performed until the intrinsic viscosity of the particles in the reactor became 0.70 dl / g, thereby preparing a polyester copolymer.

[0054] Example 2

[0055] Into a reactor with a capacity of 10 L connected to a column and a condenser capable of being cooled by water, r-BHET (3461.1 g), TPA (969.4 g), EG (12.1 g), CHDM (140.2 g), ISB (113.7 g) were introduced, and GeO2 (1.0 g) was introduced as a catalyst, phosphoric acid (1.46 g) was introduced as a stabilizer, and cobalt acetate (0.7 g) was introduced as a colorant.

[0056] Subsequently, nitrogen gas was introduced into the reactor to pressurize the reactor so that the pressure of the reactor was 1.0 kgf / cm higher than the atmospheric pressure. 2(Absolute pressure: 1495.6 mmHg). And, the temperature of the reactor was raised to 220°C within 90 minutes, maintained at 220°C for 2 hours, and then raised to 260°C within 2 hours. And then, while maintaining the temperature of the reactor at 260°C and performing the esterification reaction, the mixture in the reactor was observed with the naked eye until the mixture became transparent. During this process, the by-product was discharged through the column and the condenser. After the esterification reaction was completed, the nitrogen in the pressurized reactor was discharged to the outside to reduce the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7L capable of performing a vacuum reaction.

[0057] And, the pressure of the reactor is reduced from atmospheric pressure to 5 Torr (absolute pressure: 5mmHg) within 30 minutes, and at the same time, the temperature of the reactor is increased to 280°C within 1 hour, and the polycondensation reaction is carried out while the pressure of the reactor is maintained at 1 Torr (absolute pressure: 1mmHg) or less. At the beginning of the polycondensation reaction, the stirring speed is set to be fast, but as the polycondensation reaction proceeds, the stirring speed can be appropriately controlled when the stirring force decreases due to the increase in the viscosity of the reactants or the temperature of the reactants increases beyond the established temperature. The polycondensation reaction is carried out until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor becomes 0.60dl / g. If the intrinsic viscosity of the mixture in the reactor reaches the desired level, the mixture is discharged to the outside of the reactor to make a strand, which is solidified with a coolant, and then granulated so that the average weight becomes 12mg to 14mg.

[0058] The particles were placed at 150° C. for 1 hour for crystallization, and then introduced into a solid phase polymerization reactor having a capacity of 20 L. And then, nitrogen was flowed into the reactor at a rate of 50 L / min. Wherein, the temperature of the reactor was increased from room temperature to 140° C. at a rate of 40° C. / hour, maintained at 140° C. for 3 hours, and then increased to 200° C. at a rate of 40° C. / hour, and maintained at 200° C. Solid phase polymerization was performed until the intrinsic viscosity of the particles in the reactor became 0.95 dl / g, thereby preparing a polyester copolymer.

[0059] Example 3

[0060] Into a reactor having a capacity of 10 L connected to a column and a condenser capable of being cooled by water, r-BHET (4019.2 g), TPA (875.6 g), EG (39.2 g), CHDM (121.5 g) were introduced, and TiO2 (0.5 g) was introduced as a catalyst, phosphoric acid (1.46 g) was introduced as a stabilizer, Polysynthren Blue RLS (Clarient corporation, 0.016 g) was introduced as a blue colorant, and Solvaperm Red BB (Clarient corporation, 0.004 g) was introduced as a red colorant.

[0061] Subsequently, nitrogen gas was introduced into the reactor to pressurize the reactor so that the pressure of the reactor was 0.5 kgf / cm higher than the atmospheric pressure. 2 (Absolute pressure: 1127.8 mmHg). And, the temperature of the reactor was raised to 220°C within 90 minutes, maintained at 220°C for 2 hours, and then raised to 260°C within 2 hours. And then, while maintaining the temperature of the reactor at 260°C and performing the esterification reaction, the mixture in the reactor was observed with the naked eye until the mixture became transparent. During this process, the by-product was discharged through the column and the condenser. After the esterification reaction was completed, the nitrogen in the pressurized reactor was discharged to the outside to reduce the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7L capable of performing a vacuum reaction.

[0062] And, the pressure of the reactor is reduced from atmospheric pressure to 5 Torr (absolute pressure: 5mmHg) within 30 minutes, and at the same time, the temperature of the reactor is increased to 275°C within 1 hour, and the polycondensation reaction is carried out while the pressure of the reactor is maintained at 1 Torr (absolute pressure: 1mmHg) or less. At the beginning of the polycondensation reaction, the stirring speed is set to be fast, but as the polycondensation reaction proceeds, the stirring speed can be appropriately controlled when the stirring force decreases due to the increase in the viscosity of the reactants or the temperature of the reactants increases beyond the established temperature. The polycondensation reaction is carried out until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor becomes 0.60dl / g. If the intrinsic viscosity of the mixture in the reactor reaches the desired level, the mixture is discharged to the outside of the reactor to make a strand, which is solidified with a coolant, and then granulated so that the average weight becomes 12mg to 14mg.

[0063] The particles were placed at 150° C. for 1 hour for crystallization, and then introduced into a solid phase polymerization reactor having a capacity of 20 L. And then, nitrogen was flowed into the reactor at a rate of 50 L / min. Wherein, the temperature of the reactor was increased from room temperature to 140° C. at a rate of 40° C. / hour, maintained at 140° C. for 3 hours, and then increased to 210° C. at a rate of 40° C. / hour, and maintained at 210° C. Solid phase polymerization was performed until the intrinsic viscosity (IV) of the particles in the reactor became 0.80 dl / g, thereby preparing a polyester copolymer.

[0064] Example 4

[0065] Into a reactor having a capacity of 10 L connected to a column and a condenser capable of being cooled by water, r-BHET (795.8 g), TPA (3814.0 g), EG (1554.0 g), CHDM (188.0 g), TiO2 (0.5 g) as a catalyst, phosphoric acid (1.46 g) as a stabilizer, and cobalt acetate (1.1 g) as a colorant were introduced.

[0066] Subsequently, nitrogen gas was introduced into the reactor to pressurize the reactor so that the pressure of the reactor was 1.0 kgf / cm higher than the atmospheric pressure. 2 (Absolute pressure: 1495.6 mmHg). And, the temperature of the reactor was raised to 220°C within 90 minutes, maintained at 220°C for 2 hours, and then raised to 250°C within 2 hours. And then, while maintaining the temperature of the reactor at 250°C and performing the esterification reaction, the mixture in the reactor was observed with the naked eye until the mixture became transparent. During this process, the by-product was discharged through the column and the condenser. After the esterification reaction was completed, the nitrogen in the pressurized reactor was discharged to the outside to reduce the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7L capable of performing a vacuum reaction.

[0067] And, the pressure of the reactor is reduced from atmospheric pressure to 5 Torr (absolute pressure: 5mmHg) within 30 minutes, and at the same time, the temperature of the reactor is increased to 265°C within 1 hour, and the polycondensation reaction is carried out while the pressure of the reactor is maintained at 1 Torr (absolute pressure: 1mmHg) or less. At the beginning of the polycondensation reaction, the stirring speed is set to be fast, but as the polycondensation reaction proceeds, the stirring speed can be appropriately controlled when the stirring force decreases due to the increase in the viscosity of the reactants or the temperature of the reactants increases beyond the established temperature. The polycondensation reaction is carried out until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor becomes 0.55dl / g. If the intrinsic viscosity of the mixture in the reactor reaches the desired level, the mixture is discharged to the outside of the reactor to make a strand, which is solidified with a coolant, and then granulated so that the average weight becomes 12mg to 14mg.

[0068] The particles were placed at 150° C. for 1 hour for crystallization, and then introduced into a solid phase polymerization reactor having a capacity of 20 L. And then, nitrogen was flowed into the reactor at a rate of 50 L / min. Wherein, the temperature of the reactor was increased from room temperature to 140° C. at a rate of 40° C. / hour, maintained at 140° C. for 3 hours, and then increased to 220° C. at a rate of 40° C. / hour, and maintained at 220° C. Solid phase polymerization was performed until the intrinsic viscosity (IV) of the particles in the reactor became 0.85 dl / g, thereby preparing a polyester copolymer.

[0069] Example 5

[0070] Into a reactor having a capacity of 10 L connected to a column and a condenser capable of being cooled by water, r-BHET (2439.2 g), TPA (1471.5 g), EG (68.7 g), CHDM (797.8 g), TiO2 (1.0 g) as a catalyst, phosphoric acid (1.46 g) as a stabilizer, and cobalt acetate (0.8 g) as a colorant were introduced.

[0071] Subsequently, nitrogen gas was introduced into the reactor to pressurize the reactor so that the pressure of the reactor was 2.0 kgf / cm higher than the atmospheric pressure. 2(Absolute pressure: 2231.1 mmHg). And, the temperature of the reactor was raised to 220°C within 90 minutes, maintained at 220°C for 2 hours, and then raised to 255°C within 2 hours. And then, while maintaining the temperature of the reactor at 255°C and performing the esterification reaction, the mixture in the reactor was observed with the naked eye until the mixture became transparent. During this process, the by-product was discharged through the column and the condenser. After the esterification reaction was completed, the nitrogen in the pressurized reactor was discharged to the outside to reduce the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7L capable of performing a vacuum reaction.

[0072] And, the pressure of the reactor is reduced from atmospheric pressure to 5 Torr (absolute pressure: 5 mmHg) within 30 minutes, and at the same time, the temperature of the reactor is increased to 285°C within 1 hour, and the polycondensation reaction is carried out while maintaining the pressure of the reactor at 1 Torr (absolute pressure: 1 mmHg) or less. At the beginning of the polycondensation reaction, the stirring speed is set to be fast, but as the polycondensation reaction proceeds, the stirring speed can be appropriately controlled when the stirring force decreases due to the increase in the viscosity of the reactants or the temperature of the reactants increases beyond the established temperature. The polycondensation reaction is carried out until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor becomes 0.70 dl / g. If the intrinsic viscosity of the mixture in the reactor reaches the desired level, the mixture is discharged to the outside of the reactor to make a strand, which is solidified with a coolant, and then granulated so that the average weight becomes 12 mg to 14 mg, thereby preparing a polyester copolymer.

[0073] Example 6

[0074] Into a reactor having a capacity of 10 L connected to a column and a condenser capable of being cooled by water, r-BHET (1320.0 g), TPA (2164.2 g), EG (599.2 g), CHDM (525.1 g) were introduced, and TiO2 (1.0 g) was introduced as a catalyst, phosphoric acid (1.46 g) was introduced as a stabilizer, and cobalt acetate (1.0 g) was introduced as a colorant.

[0075] Subsequently, nitrogen gas was introduced into the reactor to pressurize the reactor so that the pressure of the reactor was 1.5 kgf / cm higher than the atmospheric pressure. 2(Absolute pressure: 1715.5 mmHg). And, the temperature of the reactor was raised to 220°C within 90 minutes, maintained at 220°C for 2 hours, and then raised to 250°C within 2 hours. And then, while maintaining the temperature of the reactor at 250°C and performing the esterification reaction, the mixture in the reactor was observed with the naked eye until the mixture became transparent. During this process, the by-product was discharged through the column and the condenser. After the esterification reaction was completed, the nitrogen in the pressurized reactor was discharged to the outside to reduce the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7L capable of performing a vacuum reaction.

[0076] And, the pressure of the reactor is reduced from atmospheric pressure to 5 Torr (absolute pressure: 5 mmHg) within 30 minutes, and at the same time, the temperature of the reactor is increased to 270°C within 1 hour, and the polycondensation reaction is carried out while maintaining the pressure of the reactor at 1 Torr (absolute pressure: 1 mmHg) or less. At the beginning of the polycondensation reaction, the stirring speed is set to be fast, but as the polycondensation reaction proceeds, the stirring speed can be appropriately controlled when the stirring force decreases due to the increase in the viscosity of the reactants or the temperature of the reactants increases beyond the established temperature. The polycondensation reaction is carried out until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor becomes 0.80 dl / g. If the intrinsic viscosity of the mixture in the reactor reaches the desired level, the mixture is discharged to the outside of the reactor to make a strand, which is solidified with a coolant, and then granulated so that the average weight becomes 12 mg to 14 mg, thereby preparing a polyester copolymer.

[0077] Example 7

[0078] Into a reactor with a capacity of 10 L connected to a column and a condenser capable of being cooled by water, r-BHET (1132.4 g), TPA (2220.2 g), EG (265.4 g), CHDM (1284.0 g), ISB (156.2 g) were introduced, and GeO2 (1.0 g) was introduced as a catalyst, phosphoric acid (1.46 g) was introduced as a stabilizer, Polysynthren Blue RLS (Clarient corporation, 0.013 g) was introduced as a blue colorant, and Solvaperm Red BB (Clarient corporation, 0.004 g) was introduced as a red colorant.

[0079] Subsequently, nitrogen gas was introduced into the reactor to pressurize the reactor so that the pressure of the reactor was 1.0 kgf / cm higher than the atmospheric pressure. 2(Absolute pressure: 1495.6 mmHg). And, the temperature of the reactor was raised to 220°C within 90 minutes, maintained at 220°C for 2 hours, and then raised to 265°C within 2 hours. And then, while maintaining the temperature of the reactor at 265°C and performing the esterification reaction, the mixture in the reactor was observed with the naked eye until the mixture became transparent. During this process, the by-product was discharged through the column and the condenser. After the esterification reaction was completed, the nitrogen in the pressurized reactor was discharged to the outside to reduce the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7L capable of performing a vacuum reaction.

[0080] And, the pressure of the reactor is reduced from atmospheric pressure to 5 Torr (absolute pressure: 5 mmHg) within 30 minutes, and at the same time, the temperature of the reactor is increased to 275°C within 1 hour, and the polycondensation reaction is carried out while maintaining the pressure of the reactor at 1 Torr (absolute pressure: 1 mmHg) or less. At the beginning of the polycondensation reaction, the stirring speed is set to be fast, but as the polycondensation reaction proceeds, the stirring speed can be appropriately controlled when the stirring force decreases due to the increase in the viscosity of the reactants or the temperature of the reactants increases beyond the established temperature. The polycondensation reaction is carried out until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor becomes 0.65 dl / g. If the intrinsic viscosity of the mixture in the reactor reaches the desired level, the mixture is discharged to the outside of the reactor to make a strand, which is solidified with a coolant, and then granulated so that the average weight becomes 12 mg to 14 mg, thereby preparing a polyester copolymer.

[0081] Example 8

[0082] Into a reactor with a capacity of 10 L connected to a column and a condenser capable of being cooled by water, r-BHET (612.8 g), TPA (2269.3 g), EG (49.9 g), CHDM (1158.0 g), ISB (587.0 g) were introduced, and GeO2 (1.0 g) was introduced as a catalyst, phosphoric acid (1.46 g) was introduced as a stabilizer, Polysynthren Blue RLS (Clarient corporation, 0.020 g) was introduced as a blue colorant, and Solvaperm Red BB (Clarient corporation, 0.008 g) was introduced as a red colorant.

[0083] Subsequently, nitrogen gas was introduced into the reactor to pressurize the reactor so that the pressure of the reactor was 0.5 kgf / cm higher than the atmospheric pressure. 2(Absolute pressure: 1127.8 mmHg). And, the temperature of the reactor was raised to 220°C within 90 minutes, maintained at 220°C for 2 hours, and then raised to 260°C within 2 hours. And then, while maintaining the temperature of the reactor at 260°C and performing the esterification reaction, the mixture in the reactor was observed with the naked eye until the mixture became transparent. During this process, the by-product was discharged through the column and the condenser. After the esterification reaction was completed, the nitrogen in the pressurized reactor was discharged to the outside to reduce the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7L capable of performing a vacuum reaction.

[0084] And, the pressure of the reactor is reduced from atmospheric pressure to 5 Torr (absolute pressure: 5 mmHg) within 30 minutes, and at the same time, the temperature of the reactor is increased to 275°C within 1 hour, and the polycondensation reaction is carried out while maintaining the pressure of the reactor at 1 Torr (absolute pressure: 1 mmHg) or less. At the beginning of the polycondensation reaction, the stirring speed is set to be fast, but as the polycondensation reaction proceeds, the stirring speed can be appropriately controlled when the stirring force decreases due to the increase in the viscosity of the reactants or the temperature of the reactants increases beyond the established temperature. The polycondensation reaction is carried out until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor becomes 0.80 dl / g. If the intrinsic viscosity of the mixture in the reactor reaches the desired level, the mixture is discharged to the outside of the reactor to make a strand, which is solidified with a coolant, and then granulated so that the average weight becomes 12 mg to 14 mg, thereby preparing a polyester copolymer.

[0085] Example 9

[0086] Into a reactor having a capacity of 10 L connected to a column and a condenser capable of being cooled by water, r-BHET (3418.5 g), TPA (957.5 g), DMT (dimethyl terephthalate; 1119.0 g), EG (346 g), CHDM (221.5 g), ISB (84.2 g) were introduced, and manganese (II) acetate tetrahydrate (1.5 g) and Sb2O3 (1.8 g) were introduced as catalysts, and cobalt acetate (0.7 g) was introduced as a colorant.

[0087] Subsequently, nitrogen was introduced into the reactor so that the pressure of the reactor became atmospheric pressure. Also, the temperature of the reactor was raised to 220°C within 90 minutes, maintained at 220°C for 2 hours, and then raised to 240°C within 2 hours. And then, while the temperature of the reactor was maintained at 240°C and esterification was carried out, the mixture in the reactor was observed with the naked eye until the mixture became transparent. During this process, by-products were discharged through a column and a condenser. After the esterification was completed, the nitrogen in the pressurized reactor was discharged to the outside to reduce the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7L capable of vacuum reaction.

[0088] And, the pressure of the reactor is reduced from atmospheric pressure to 5 Torr (absolute pressure: 5mmHg) within 30 minutes, and at the same time, the temperature of the reactor is increased to 265°C within 1 hour, and the polycondensation reaction is carried out while the pressure of the reactor is maintained at 1 Torr (absolute pressure: 1mmHg) or less. At the beginning of the polycondensation reaction, the stirring speed is set to be fast, but as the polycondensation reaction proceeds, the stirring speed can be appropriately controlled when the stirring force decreases due to the increase in the viscosity of the reactants or the temperature of the reactants increases beyond the established temperature. The polycondensation reaction is carried out until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor becomes 0.60dl / g. If the intrinsic viscosity of the mixture in the reactor reaches the desired level, the mixture is discharged to the outside of the reactor to make a strand, which is solidified with a coolant, and then granulated so that the average weight becomes 12mg to 14mg.

[0089] The particles were placed at 150° C. for 1 hour for crystallization, and then introduced into a solid phase polymerization reactor having a capacity of 20 L. And then, nitrogen was flowed into the reactor at a rate of 50 L / min. Wherein, the temperature of the reactor was increased from room temperature to 140° C. at a rate of 40° C. / hour, maintained at 140° C. for 3 hours, and then increased to 200° C. at a rate of 40° C. / hour, and maintained at 200° C. Solid phase polymerization was performed until the intrinsic viscosity (IV) of the particles in the reactor became 0.95 dl / g, thereby preparing a polyester copolymer.

[0090] Example 10

[0091] Into a reactor with a capacity of 10 L connected to a column and a condenser capable of being cooled by water, r-BHET (3461.1 g), TPA (969.4 g), IPA (isophthalic acid; 2262.0 g), EG (12.1 g), CHDM (140.2 g), ISB (113.7 g) were introduced, and GeO2 (1.0 g) was introduced as a catalyst, and cobalt acetate (0.7 g) was introduced as a colorant.

[0092] Subsequently, nitrogen gas was introduced into the reactor to pressurize the reactor so that the pressure of the reactor was 1.0 kgf / cm higher than the atmospheric pressure. 2 (Absolute pressure: 1495.6 mmHg). And, the temperature of the reactor was raised to 220°C within 90 minutes, maintained at 220°C for 2 hours, and then raised to 260°C within 2 hours. And then, while maintaining the temperature of the reactor at 260°C and performing the esterification reaction, the mixture in the reactor was observed with the naked eye until the mixture became transparent. During this process, the by-product was discharged through the column and the condenser. After the esterification reaction was completed, the nitrogen in the pressurized reactor was discharged to the outside to reduce the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7L capable of performing a vacuum reaction.

[0093] And, the pressure of the reactor is reduced from atmospheric pressure to 5 Torr (absolute pressure: 5mmHg) within 30 minutes, and at the same time, the temperature of the reactor is increased to 280°C within 1 hour, and the polycondensation reaction is carried out while the pressure of the reactor is maintained at 1 Torr (absolute pressure: 1mmHg) or less. At the beginning of the polycondensation reaction, the stirring speed is set to be fast, but as the polycondensation reaction proceeds, the stirring speed can be appropriately controlled when the stirring force decreases due to the increase in the viscosity of the reactants or the temperature of the reactants increases beyond the established temperature. The polycondensation reaction is carried out until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor becomes 0.60dl / g. If the intrinsic viscosity of the mixture in the reactor reaches the desired level, the mixture is discharged to the outside of the reactor to make a strand, which is solidified with a coolant, and then granulated so that the average weight becomes 12mg to 14mg.

[0094] The particles were placed at 150° C. for 1 hour for crystallization, and then introduced into a solid phase polymerization reactor having a capacity of 20 L. And then, nitrogen was flowed into the reactor at a rate of 50 L / min. Wherein, the temperature of the reactor was increased from room temperature to 140° C. at a rate of 40° C. / hour, maintained at 140° C. for 3 hours, and then increased to 190° C. at a rate of 40° C. / hour, and maintained at 190° C. Solid phase polymerization was performed until the intrinsic viscosity (IV) of the particles in the reactor became 1.0 dl / g, thereby preparing a polyester copolymer.

[0095] Comparative Example 1

[0096] Into a reactor having a capacity of 10 L connected to a column and a condenser capable of being cooled by water, r-BHET (390.7 g), TPA (2936.3 g), EG (1400.7 g), CHDM (221.5 g), ISB (98.2 g) were introduced, GeO2 (1.0 g) was introduced as a catalyst, and phosphoric acid (1.46 g) was introduced as a stabilizer.

[0097] Subsequently, nitrogen gas was introduced into the reactor to pressurize the reactor so that the pressure of the reactor was 0.5 kgf / cm higher than the atmospheric pressure. 2 (Absolute pressure: 1127.8 mmHg). And, the temperature of the reactor was raised to 220°C within 90 minutes, maintained at 220°C for 2 hours, and then raised to 260°C within 2 hours. And then, while maintaining the temperature of the reactor at 260°C and performing the esterification reaction, the mixture in the reactor was observed with the naked eye until the mixture became transparent. During this process, the by-product was discharged through the column and the condenser. After the esterification reaction was completed, the nitrogen in the pressurized reactor was discharged to the outside to reduce the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7L capable of performing a vacuum reaction.

[0098] And, the pressure of the reactor is reduced from atmospheric pressure to 5 Torr (absolute pressure: 5mmHg) within 30 minutes, and at the same time, the temperature of the reactor is increased to 280°C within 1 hour, and the polycondensation reaction is carried out while the pressure of the reactor is maintained at 1 Torr (absolute pressure: 1mmHg) or less. At the beginning of the polycondensation reaction, the stirring speed is set to be fast, but as the polycondensation reaction proceeds, the stirring speed can be appropriately controlled when the stirring force decreases due to the increase in the viscosity of the reactants or the temperature of the reactants increases beyond the established temperature. The polycondensation reaction is carried out until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor becomes 0.60dl / g. If the intrinsic viscosity of the mixture in the reactor reaches the desired level, the mixture is discharged to the outside of the reactor to make a strand, which is solidified with a coolant, and then granulated so that the average weight becomes 12mg to 14mg.

[0099] The particles were placed at 150° C. for 1 hour for crystallization, and then introduced into a solid phase polymerization reactor having a capacity of 20 L. After being maintained at 100 mmHg for 1 hour, nitrogen was flowed into the reactor at a rate of 50 L / min. The temperature of the reactor was increased from room temperature to 140° C. at a rate of 40° C. / hour, maintained at 140° C. for 3 hours, and then increased to 200° C. at a rate of 40° C. / hour, and maintained at 200° C. The solid phase polymerization reaction was performed until the intrinsic viscosity (IV) of the particles in the reactor became 0.7 dl / g, thereby preparing a polyester copolymer.

[0100] Comparative Example 2

[0101] Into a reactor with a capacity of 10 L connected to a column and a condenser capable of being cooled by water, r-BHET (2645.6 g), TPA (1729.0 g), EG (6.5 g), CHDM (150.0 g), ISB (106.4 g) were introduced, and GeO2 (1.0 g) was introduced as a catalyst, phosphoric acid (1.46 g) was introduced as a stabilizer, and cobalt acetate (0.7 g) was introduced as a colorant.

[0102] Subsequently, nitrogen gas was introduced into the reactor to pressurize the reactor so that the pressure of the reactor was 1.0 kgf / cm higher than the atmospheric pressure. 2 (Absolute pressure: 1495.6 mmHg). And, the temperature of the reactor was raised to 220°C within 90 minutes, maintained at 220°C for 2 hours, and then raised to 260°C within 2 hours. And then, while maintaining the temperature of the reactor at 260°C and performing the esterification reaction, the mixture in the reactor was observed with the naked eye until the mixture became transparent. During this process, the by-product was discharged through the column and the condenser. After the esterification reaction was completed, the nitrogen in the pressurized reactor was discharged to the outside to reduce the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7L capable of performing a vacuum reaction.

[0103] And, the pressure of the reactor is reduced from atmospheric pressure to 5 Torr (absolute pressure: 5mmHg) within 30 minutes, and at the same time, the temperature of the reactor is increased to 280°C within 1 hour, and the polycondensation reaction is carried out while the pressure of the reactor is maintained at 1 Torr (absolute pressure: 1mmHg) or less. At the beginning of the polycondensation reaction, the stirring speed is set to be fast, but as the polycondensation reaction proceeds, the stirring speed can be appropriately controlled when the stirring force decreases due to the increase in the viscosity of the reactants or the temperature of the reactants increases beyond the established temperature. The polycondensation reaction is carried out until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor becomes 0.60dl / g. If the intrinsic viscosity of the mixture in the reactor reaches the desired level, the mixture is discharged to the outside of the reactor to make a strand, which is solidified with a coolant, and then granulated so that the average weight becomes 12mg to 14mg.

[0104] The particles were placed at 150° C. for 1 hour for crystallization, and then introduced into a solid phase polymerization reactor having a capacity of 20 L. And then, nitrogen was flowed into the reactor at a rate of 50 L / min. Wherein, the temperature of the reactor was increased from room temperature to 140° C. at a rate of 40° C. / hour, maintained at 140° C. for 3 hours, and then increased to 200° C. at a rate of 40° C. / hour, and maintained at 200° C. Solid phase polymerization was performed until the intrinsic viscosity (IV) of the particles in the reactor became 0.95 dl / g, thereby preparing a polyester copolymer.

[0105] Comparative Example 3

[0106] Into a reactor having a capacity of 10 L connected to a column and a condenser capable of being cooled by water, r-BHET (364.2 g), TPA (3162.2 g), EG (1295.4 g), CHDM (118.0 g) were introduced, and GeO2 (1.0 g) was introduced as a catalyst, phosphoric acid (1.46 g) was introduced as a stabilizer, Polysynthren Blue RLS (Clarient corporation, 0.012 g) was introduced as a blue colorant, and Solvaperm Red BB (Clarient corporation, 0.004 g) was introduced as a red colorant.

[0107] Subsequently, nitrogen gas was introduced into the reactor to pressurize the reactor so that the pressure of the reactor was 0.5 kgf / cm higher than the atmospheric pressure. 2(Absolute pressure: 1127.8 mmHg). And, the temperature of the reactor was raised to 220°C within 90 minutes, maintained at 220°C for 2 hours, and then raised to 255°C within 2 hours. And then, while maintaining the temperature of the reactor at 255°C and performing the esterification reaction, the mixture in the reactor was observed with the naked eye until the mixture became transparent. During this process, the by-product was discharged through the column and the condenser. After the esterification reaction was completed, the nitrogen in the pressurized reactor was discharged to the outside to reduce the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7L capable of performing a vacuum reaction.

[0108] And, the pressure of the reactor is reduced from atmospheric pressure to 5 Torr (absolute pressure: 5mmHg) within 30 minutes, and at the same time, the temperature of the reactor is increased to 280°C within 1 hour, and the polycondensation reaction is carried out while the pressure of the reactor is maintained at 1 Torr (absolute pressure: 1mmHg) or less. At the beginning of the polycondensation reaction, the stirring speed is set to be fast, but as the polycondensation reaction proceeds, the stirring speed can be appropriately controlled when the stirring force decreases due to the increase in the viscosity of the reactants or the temperature of the reactants increases beyond the established temperature. The polycondensation reaction is carried out until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor becomes 0.75dl / g. If the intrinsic viscosity of the mixture in the reactor reaches the desired level, the mixture is discharged to the outside of the reactor to make a strand, which is solidified with a coolant, and then granulated so that the average weight becomes 12mg to 14mg.

[0109] The particles were placed at 150° C. for 1 hour for crystallization, and then introduced into a solid phase polymerization reactor having a capacity of 20 L. And then, nitrogen was flowed into the reactor at a rate of 50 L / min. Wherein, the temperature of the reactor was increased from room temperature to 140° C. at a rate of 40° C. / hour, maintained at 140° C. for 3 hours, and then increased to 210° C. at a rate of 40° C. / hour, and maintained at 210° C. Solid phase polymerization was performed until the intrinsic viscosity (IV) of the particles in the reactor became 0.80 dl / g, thereby preparing a polyester copolymer.

[0110] Comparative Example 4

[0111] Into a reactor having a capacity of 10 L connected to a column and a condenser capable of being cooled by water, r-BHET (3194.9 g), TPA (623.7 g), CHDM (94.1 g) were introduced, and GeO2 (1.0 g) was introduced as a catalyst, phosphoric acid (1.46 g) was introduced as a stabilizer, Polysynthren Blue RLS (Clarient corporation, 0.010 g) was introduced as a blue colorant, and Solvaperm Red BB (Clarient corporation, 0.003 g) was introduced as a red colorant.

[0112] Subsequently, nitrogen gas was introduced into the reactor to pressurize the reactor so that the pressure of the reactor was 1.5 kgf / cm higher than the atmospheric pressure. 2 (Absolute pressure: 1715.5 mmHg). And, the temperature of the reactor was raised to 220°C within 90 minutes, maintained at 220°C for 2 hours, and then raised to 260°C within 2 hours. And then, while maintaining the temperature of the reactor at 260°C and performing the esterification reaction, the mixture in the reactor was observed with the naked eye until the mixture became transparent. During this process, the by-product was discharged through the column and the condenser. After the esterification reaction was completed, the nitrogen in the pressurized reactor was discharged to the outside to reduce the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7L capable of performing a vacuum reaction.

[0113] And, the pressure of the reactor is reduced from atmospheric pressure to 5 Torr (absolute pressure: 5mmHg) within 30 minutes, and at the same time, the temperature of the reactor is increased to 270°C within 1 hour, and the polycondensation reaction is carried out while the pressure of the reactor is maintained at 1 Torr (absolute pressure: 1mmHg) or less. At the beginning of the polycondensation reaction, the stirring speed is set to be fast, but as the polycondensation reaction proceeds, the stirring speed can be appropriately controlled when the stirring force decreases due to the increase in the viscosity of the reactants or the temperature of the reactants increases beyond the established temperature. The polycondensation reaction is carried out until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor becomes 0.65dl / g. If the intrinsic viscosity of the mixture in the reactor reaches the desired level, the mixture is discharged to the outside of the reactor to make a strand, which is solidified with a coolant, and then granulated so that the average weight becomes 12mg to 14mg.

[0114] The particles were placed at 150° C. for 1 hour for crystallization, and then introduced into a solid phase polymerization reactor having a capacity of 20 L. And then, nitrogen was flowed into the reactor at a rate of 50 L / min. Wherein, the temperature of the reactor was increased from room temperature to 140° C. at a rate of 40° C. / hour, maintained at 140° C. for 3 hours, and then increased to 220° C. at a rate of 40° C. / hour, and maintained at 220° C. Solid phase polymerization was performed until the intrinsic viscosity (IV) of the particles in the reactor became 0.85 dl / g, thereby preparing a polyester copolymer.

[0115] Comparative Example 5

[0116] Into a reactor having a capacity of 10 L connected to a column and a condenser capable of being cooled by water, r-BHET (320.1 g), TPA (3009.6 g), EG (1166.1 g), CHDM (837.7 g) were introduced, and GeO2 (1.0 g) was introduced as a catalyst, phosphoric acid (1.5 g) was introduced as a stabilizer, and cobalt acetate (0.7 g) was introduced as a colorant.

[0117] Subsequently, nitrogen gas was introduced into the reactor to pressurize the reactor so that the pressure of the reactor was 2.0 kgf / cm higher than the atmospheric pressure. 2 (Absolute pressure: 2231.1 mmHg). And, the temperature of the reactor was raised to 220°C within 90 minutes, maintained at 220°C for 2 hours, and then raised to 265°C within 2 hours. And then, while maintaining the temperature of the reactor at 265°C and performing the esterification reaction, the mixture in the reactor was observed with the naked eye until the mixture became transparent. During this process, the by-product was discharged through the column and the condenser. After the esterification reaction was completed, the nitrogen in the pressurized reactor was discharged to the outside to reduce the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7L capable of performing a vacuum reaction.

[0118] And, the pressure of the reactor is reduced from atmospheric pressure to 5 Torr (absolute pressure: 5 mmHg) within 30 minutes, and at the same time, the temperature of the reactor is increased to 270°C within 1 hour, and the polycondensation reaction is carried out while maintaining the pressure of the reactor at 1 Torr (absolute pressure: 1 mmHg) or less. At the beginning of the polycondensation reaction, the stirring speed is set to be fast, but as the polycondensation reaction proceeds, the stirring speed can be appropriately controlled when the stirring force decreases due to the increase in the viscosity of the reactants or the temperature of the reactants increases beyond the established temperature. The polycondensation reaction is carried out until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor becomes 0.60 dl / g. If the intrinsic viscosity of the mixture in the reactor reaches the desired level, the mixture is discharged to the outside of the reactor to make a strand, which is solidified with a coolant, and then granulated so that the average weight becomes 12 mg to 14 mg, thereby preparing a polyester copolymer.

[0119] Comparative Example 6

[0120] Into a reactor having a capacity of 10 L connected to a column and a condenser capable of being cooled by water, r-BHET (4278.0 g), TPA (310.7 g), CHDM (539.0 g), GeO2 (1.0 g) as a catalyst, phosphoric acid (1.46 g) as a stabilizer, and cobalt acetate (0.8 g) as a colorant were introduced.

[0121] Subsequently, nitrogen gas was introduced into the reactor to pressurize the reactor so that the pressure of the reactor was 1.5 kgf / cm higher than the atmospheric pressure. 2 (Absolute pressure: 1715.5 mmHg). And, the temperature of the reactor was raised to 220°C within 90 minutes, maintained at 220°C for 2 hours, and then raised to 270°C within 2 hours. And then, while maintaining the temperature of the reactor at 270°C and performing the esterification reaction, the mixture in the reactor was observed with the naked eye until the mixture became transparent. During this process, the by-product was discharged through the column and the condenser. After the esterification reaction was completed, the nitrogen in the pressurized reactor was discharged to the outside to reduce the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7L capable of performing a vacuum reaction.

[0122] And, the pressure of the reactor is reduced from atmospheric pressure to 5 Torr (absolute pressure: 5 mmHg) within 30 minutes, and at the same time, the temperature of the reactor is increased to 275°C within 1 hour, and the polycondensation reaction is carried out while maintaining the pressure of the reactor at 1 Torr (absolute pressure: 1 mmHg) or less. At the beginning of the polycondensation reaction, the stirring speed is set to be fast, but as the polycondensation reaction proceeds, the stirring speed can be appropriately controlled when the stirring force decreases due to the increase in the viscosity of the reactants or the temperature of the reactants increases beyond the established temperature. The polycondensation reaction is carried out until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor becomes 0.65 dl / g. If the intrinsic viscosity of the mixture in the reactor reaches the desired level, the mixture is discharged to the outside of the reactor to make a strand, which is solidified with a coolant, and then granulated so that the average weight becomes 12 mg to 14 mg, thereby preparing a polyester copolymer.

[0123] Comparative Example 7

[0124] Into a reactor with a capacity of 10 L connected to a column and a condenser capable of being cooled by water, r-BHET (420.6 g), TPA (2473.9 g), EG (657.1 g), CHDM (1192.3 g), ISB (145.1 g) were introduced, and GeO2 (1.0 g) was introduced as a catalyst, phosphoric acid (1.46 g) was introduced as a stabilizer, and cobalt acetate (0.8 g) was introduced as a colorant.

[0125] Subsequently, nitrogen gas was introduced into the reactor to pressurize the reactor so that the pressure of the reactor was 1.5 kgf / cm higher than the atmospheric pressure. 2 (Absolute pressure: 1715.5 mmHg). And, the temperature of the reactor was raised to 220°C within 90 minutes, maintained at 220°C for 2 hours, and then raised to 270°C within 2 hours. And then, while maintaining the temperature of the reactor at 270°C and performing the esterification reaction, the mixture in the reactor was observed with the naked eye until the mixture became transparent. During this process, the by-product was discharged through the column and the condenser. After the esterification reaction was completed, the nitrogen in the pressurized reactor was discharged to the outside to reduce the pressure of the reactor to atmospheric pressure, and then, the mixture in the reactor was transferred to a reactor with a capacity of 7L capable of performing a vacuum reaction.

[0126] And, the pressure of the reactor is reduced from atmospheric pressure to 5 Torr (absolute pressure: 5 mmHg) within 30 minutes, and at the same time, the temperature of the reactor is increased to 275°C within 1 hour, and the polycondensation reaction is carried out while maintaining the pressure of the reactor at 1 Torr (absolute pressure: 1 mmHg) or less. At the beginning of the polycondensation reaction, the stirring speed is set to be fast, but as the polycondensation reaction proceeds, the stirring speed can be appropriately controlled when the stirring force decreases due to the increase in the viscosity of the reactants or the temperature of the reactants increases beyond the established temperature. The polycondensation reaction is carried out until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor becomes 0.70 dl / g. If the intrinsic viscosity of the mixture in the reactor reaches the desired level, the mixture is discharged to the outside of the reactor to make a strand, which is solidified with a coolant, and then granulated so that the average weight becomes 12 mg to 14 mg, thereby preparing a polyester copolymer.

[0127] The contents of the components introduced to prepare the polyester copolymer in Examples and Comparative Examples are shown in Table 1 below.

[0128] [Table 1]

[0129]

[0130]

[0131] Experimental Examples

[0132] For the copolymers prepared in Examples and Comparative Examples, properties were evaluated as follows.

[0133] (1) Residue composition

[0134] After the sample was dissolved in a CDCl3 solvent at a concentration of 3 mg / mL, the composition (mol%) of the residues derived from the acid and the diol in the polyester copolymer was confirmed by 1H-NMR obtained using a nuclear magnetic resonance apparatus (JEOL, 600 MHz FT-NMR) at 25° C. Also, the TMA residue was confirmed by quantitatively analyzing the content of benzene-1,2,4-triethylcarboxylate produced by the reaction of ethanol with TMA via ethanolysis through a spectrum measured at 250° C. using gas chromatography (Agilent Technologies, 7890B), and the content (wt%) based on the total weight of the polyester copolymer was confirmed.

[0135] (2) Intrinsic viscosity

[0136] The polyester copolymer was dissolved in 150°C o-chlorophenol (OCP) at a concentration of 0.12%, and then, the intrinsic viscosity was measured using an Ubbelohde viscometer in a constant temperature bath at 35°C. Specifically, the temperature of the viscometer was maintained at 35°C, and the outflow time (t0) required for the solvent to pass between specific internal sections of the viscometer and the time (t) required for the solution to pass were measured. And then, the t0 value and the t value were substituted into the following formula 1 to calculate the specific viscosity, and the calculated specific viscosity value was substituted into the following formula 2 to calculate the intrinsic viscosity.

[0137] [Formula 1]

[0138]

[0139] [Formula 2]

[0140]

[0141] (3) Haze

[0142] A polyester copolymer sample having a thickness of 6 mm was prepared, and the haze of the sample was measured by the ASTM D1003-97 measuring method using a CM-3600A measuring device of Minolta Inc.

[0143] (4) Substrate color Lb

[0144] The chromaticity and brightness of the samples were measured using a Varian Cary 5UV / Vis / NIR spectrophotometer equipped with a diffuse reflectance component. Polyester copolymer samples were prepared with a thickness of 6 mm, and the transmission data was obtained using a light source D65 at an observer angle of 2°, which was processed using the color analysis tool in Grams / 32 software to calculate Hunter L*a*b*, and Lb is described in the following table.

[0145] (5) By-products

[0146] The by-products are measured by GC quantitative analysis of the polyester copolymer, and specifically, measured under the following conditions.

[0147] a. Sample pretreatment: 0.1 g of sample was dissolved in 5 mL of MeOH.

[0148] b.GC conditions

[0149] i. Model: Agilent 7890

[0150] ii. Column: DB-WAX (30m*0.25mm*0.25μm)

[0151] iii. Oven temperature: 50℃(2min)-10℃ / min-250℃(5min)

[0152] iv. Injector temperature: 250°C

[0153] v. Detector temperature: 250℃

[0154] vi. Flow rate: 1.5mL / min (N2), split ratio: 1 / 30

[0155] Quantitative analysis of diols other than EG (ethylene glycol) was performed to measure the total amount of by-products.

[0156] The results are shown in Table 2 below.

[0157] [Table 2]

[0158]

Claims

1. A method for preparing a polyester copolymer, comprising the following steps: Step 1: subjecting recycled bis-2-hydroxyethyl terephthalate, dicarboxylic acid or its derivative, and diol including ethylene glycol and a comonomer to an esterification reaction; as well as Step 2: subjecting the product of step 1 to a polycondensation reaction, wherein The polyester copolymer has a structure in which a portion derived from the bis-2-hydroxyethyl terephthalate, an acid portion derived from the dicarboxylic acid or a derivative thereof, and a diol portion derived from the diol are repeated, The polyester copolymer comprises 10 wt% to 80 wt% of a portion derived from recycled bis-2-hydroxyethyl terephthalate, The molar ratio of the diol to the dicarboxylic acid or its derivative is 0.2:1 to 1.35:1, For a sample having a thickness of 6 mm, (Hunter L color value)-(Hunter b color value) of the polyester copolymer is 85 or more, The intrinsic viscosity of the polyester copolymer is 0.55 dl / g to 0.80 dl / g, and The comonomer is cyclohexanedimethanol or isosorbide.

2. The method according to claim 1, The molar ratio of the comonomer to ethylene glycol is 0.1:1 to 20:

1.

3. The method according to claim 1, The by-product of the polyester copolymer is 2.0 wt% or less.

4. The method according to claim 1, wherein the polyester copolymer has a haze of 4 or less.

5. The method according to claim 1, The by-product of the polyester copolymer is 1.5 wt% or less.

6. The method according to claim 1, wherein the polyester copolymer has a haze of 1.5 or less.

7. The method according to claim 1, The esterification reaction is carried out in the presence of an esterification catalyst, which includes zinc acetate, zinc acetate dihydrate, zinc chloride, zinc sulfate, zinc sulfide, zinc carbonate, zinc citrate, zinc gluconate or a mixture thereof.

8. The method according to claim 1, The polycondensation reaction is carried out in the presence of a polycondensation catalyst, which includes a titanium-based compound, a germanium-based compound, an antimony-based compound, an aluminum-based compound, a tin-based compound or a mixture thereof.

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