Polyester resin and preparation method therefor

Abstract

Provided are a polyester resin including a structural unit represented by chemical formula 1 and a preparation method therefor. [Chemical formula 1] (In chemical formula 1, R1 to R10, n, m, x, and y are as defined in the specification.)

Description

Polyester resin and method for producing the same

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

[0002] Polylactic acid (PLA), a representative biodegradable polymer, is undergoing application tests in various industrial fields due to its excellent mechanical properties.

[0003] However, PLA has low biodegradability and is difficult to use alone due to its brittle polymer properties, so it is being commercialized after improving its properties through compounding with other resins.

[0004] One embodiment provides a polyester resin having excellent biodegradability, mechanical properties and color characteristics.

[0005] Another embodiment provides a method for producing the polyester resin.

[0006] According to one embodiment, a polyester resin comprising a structural unit represented by the following chemical formula 1 is provided.

[0007] [Chemical Formula 1]

[0008]

[0009] (In the above chemical formula 1,

[0010] R 1 Inland R 10 are each independently a hydrogen atom, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C3 to C20 cycloalkenyl group, a substituted or unsubstituted C3 to C20 cycloalkynyl group, or a substituted or unsubstituted C6 to C30 aryl group,

[0011] n is an integer from 1 to 10, m is an integer from 1 to 10, x is an integer from 2 to 100, and y is an integer from 2 to 100.)

[0012] In the above chemical formula 1, the ratio of x and y can be 50:1 to 1:50.

[0013] The above polyester resin may have a randomness of greater than 1 and less than or equal to 1.1 as determined by NMR analysis.

[0014] The above polyester resin contains a carboxyl group at the terminal, and the acid value of the carboxyl group at the terminal may be 10 eq / ton to 25 eq / ton.

[0015] The number average molecular weight of the above polyester resin may be 47,000 g / mol to 147,000 g / mol.

[0016] The glass transition temperature (Tg) of the above polyester resin may be 30°C to 70°C.

[0017] The above polyester resin may have an L* value of 60 to 80 according to the CIE1976 L*a*b* colorimetric system, an a* value of -2.5 to 0, and a b* value of 0.1 to 9.

[0018] The intrinsic viscosity (25°C) of the above polyester resin may be 1.1 dl / g to 2.8 dl / g.

[0019] According to another embodiment, a method for producing the polyester resin is provided, comprising: a step of reacting lactic acid under a first catalyst to produce lactide; a step of reacting a furan dicarboxylic acid-based compound and an aliphatic diol-based compound under a second catalyst to produce a furan-based oligomer; a step of ring-opening polymerizing the lactide under the first catalyst to produce a lactide oligomer; and a step of introducing the furan-based oligomer into the lactide oligomer and reacting the furan-based oligomer under a second catalyst to produce a copolymer, wherein the first catalyst and the second catalyst include a titanium (Ti)-based catalyst, a tin (Sn)-based catalyst, or a combination thereof, and the first catalyst and the second catalyst are different from each other.

[0020] The first catalyst may include a tin (Sn)-based catalyst, and the second catalyst may include a titanium (Ti)-based catalyst.

[0021] The molar ratio of the first catalyst in the step of producing the lactide oligomer and the second catalyst in the step of producing the copolymer may be 1:10 to 10:1.

[0022] The step of manufacturing the above lactide may include a step of adding an aliphatic diol compound.

[0023] The above furan dicarboxylic acid compound may include 2,5-furandicarboxylic acid, and the above aliphatic diol compound may include butanediol.

[0024] In the step of manufacturing the above furan-based oligomer, the furan dicarboxylic acid-based compound and the aliphatic diol-based compound can react at a molar ratio of 1:1.1 to 1:1.8.

[0025] The step of preparing the above furan-based oligomer may include a step of partially removing the above aliphatic diol-based compound.

[0026] The number average molecular weight of the above furan oligomer may be 1,000 g / mol to 3,000 g / mol.

[0027] The number average molecular weight of the above lactide oligomer may be 5,000 g / mol to 10,000 g / mol.

[0028] In the step of manufacturing the above copolymer, the lactide oligomer and the furan-based oligomer can react at a molar ratio of 50:1 to 1:50.

[0029] The polyester resin according to one embodiment is a biodegradable polymer and has excellent biodegradability, mechanical properties, and color characteristics, and thus can be used alone as a material for various products.

[0030] Below, implementation examples are described in detail so that those skilled in the art can easily implement them. However, the implementation examples can be implemented in various different forms and are not limited to the implementation examples described herein.

[0031] Throughout the specification, whenever 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.

[0032] Also, throughout the specification, "substitution" means that at least one hydrogen atom is substituted with a halogen atom (F, Cl, Br, I), a hydroxy group, a C1 to C20 alkoxy group, a nitro group, a cyano group, an amine group, an imino group, an azido group, an amidino group, a hydrazino group, a hydrazono group, a carbonyl group, a carbamyl group, a thiol group, an ester group, an ether group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, a C1 to C20 alkyl group, a C2 to C20 alkenyl group, a C2 to C20 alkynyl group, a C6 to C20 aryl group, a C3 to C20 cycloalkyl group, a C3 to C20 cycloalkenyl group, a C3 to C20 cycloalkynyl group, a C2 to C20 heterocycloalkyl group, a C2 to C20 heterocycloalkenyl group, a C2 to C20 It means substituted with a heterocycloalkynyl group, a C3 to C20 heteroaryl group, or a combination thereof.

[0033] Also, throughout the specification, the CIE1976 L*a*b* color space is defined by the CIE (International Commission on Illumination) and corresponds to the color space that is currently standardized worldwide. In this CIE1976 L*a*b* color space, the L* value represents brightness in color coordinates, and the range is 0 to 100, with 0 representing complete black and 100 representing complete white. a* represents whether it leans toward red or green. If this value is positive, that is, "+", it is red, and if it is negative, that is, "-", it is green. b* represents whether it leans toward yellow or blue. If this value is positive, that is, "+", it is yellow, and if it is negative, that is, "-", it is blue.

[0034] A polyester resin according to one embodiment is a biodegradable polymer and includes a structural unit represented by the following chemical formula 1. Specifically, the polyester resin according to one embodiment may be a copolymer including a structural unit represented by the following chemical formula 1.

[0035] [Chemical Formula 1]

[0036]

[0037] In chemical formula 1, R 1 Inland R 10 are each independently a hydrogen atom, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C3 to C20 cycloalkenyl group, a substituted or unsubstituted C3 to C20 cycloalkynyl group, or a substituted or unsubstituted C6 to C30 aryl group. For example, R 1 Inland R 10 Each may independently be a hydrogen atom, or a substituted or unsubstituted C1 to C20 alkyl group.

[0038] In chemical formula 1, n is an integer from 1 to 10, and may be, for example, an integer from 2 to 6 or an integer from 2 to 4.

[0039] In chemical formula 1, m is an integer from 1 to 10, and may be, for example, an integer from 2 to 8 or an integer from 3 to 7.

[0040] In chemical formula 1, x represents a first repeating unit, and the first repeating unit may have a structure of a residue derived from a furan oligomer formed by the reaction of a furan dicarboxylic acid compound and an aliphatic diol compound. x is an integer from 2 to 100, and may be, for example, an integer from 2 to 50 or an integer from 2 to 10.

[0041] A polyester resin according to one embodiment can improve the brittle properties of conventional polylactic acid (PLA) and enhance biodegradability by including the first repeating unit, that is, by having a residue derived from a furan oligomer formed by a reaction between a furan dicarboxylic acid compound, which is a bio-derived raw material, and an aliphatic diol compound.

[0042] In chemical formula 1, y represents a second repeating unit, and the second repeating unit may have a structure of a residue derived from a lactide oligomer formed by ring-opening polymerization of lactide. y is an integer from 2 to 100, and may be, for example, an integer from 2 to 50 or an integer from 2 to 10.

[0043] When x representing the first repeating unit and y representing the second repeating unit are each within the above range, a polyester resin having excellent biodegradability, mechanical properties, and color characteristics can be secured by having the form of a block copolymer.

[0044] Specifically, the ratio of x and y can be 50:1 to 1:50, for example 9:1 to 1:9. When the ratio of x and y is within the above range, a polyester resin having excellent biodegradability, mechanical properties, and color characteristics can be obtained.

[0045] In chemical formula 1, * indicates a bonding position.

[0046] According to one embodiment, a polyester resin, specifically a copolymer including a structural unit represented by Chemical Formula 1, may have a randomness by NMR analysis of greater than 1 and less than or equal to 1.1, for example, 1.01 to 1.09, 1.01 to 1.08. When the randomness is within the above range, a polyester resin having excellent biodegradability, mechanical properties, and color characteristics can be obtained.

[0047] The randomness of the copolymer can be obtained by 1H NMR measurement. For example, first, 0.1 mg of a polyester resin, i.e., a copolymer including a structural unit represented by the above chemical formula 1, is placed in a 10 ml vial, and a CF3COOD solvent is added at a concentration of 10 wt% to dissolve it at room temperature. 1H NMR is measured, and the furan peak observed around 7.2 ppm to 7.4 ppm is integrated by 2 to calculate the area of ​​the butylene unit from 4.1 ppm to 4.5 ppm. The randomness can be obtained by substituting this integral value into the following mathematical equation.

[0048]

[0049] The above polyester resin, specifically the copolymer including the structural unit represented by Chemical Formula 1, may include a carboxyl group at the terminal. The acid value, which indicates the concentration of the carboxyl group at the terminal, may be 10 eq / ton to 25 eq / ton, for example, 11 eq / ton to 25 eq / ton. When the acid value of the carboxyl group at the terminal is within the above range, a polyester resin having excellent biodegradability, mechanical properties, and color characteristics can be obtained.

[0050] The number average molecular weight of the above polyester resin may be 47,000 g / mol to 147,000 g / mol, for example 50,000 g / mol to 140,000 g / mol. When the number average molecular weight of the polyester resin is within the above range, the film processability is excellent, and the productivity and yield are improved as it has an appropriate viscosity, and the biodegradability, mechanical properties, and color characteristics are excellent.

[0051] The glass transition temperature (Tg) of the above polyester resin may be 30°C to 70°C, for example, 35°C to 60°C. When the glass transition temperature (Tg) of the polyester resin is within the above range, it has thermal stability, excellent film processability, and excellent biodegradability, mechanical properties, and color characteristics.

[0052] The polyester resin may have an L* value of 60 to 80, an a* value of -2.5 to 0, and a b* value of 0.1 to 9 according to the CIE1976 L*a*b* colorimetric system. This can be measured with a CM-3700A device from Konica Minolta. For reference, a higher L* value may indicate a color closer to white, a lower a* value may indicate a lighter red and a darker green, and a lower b* value may indicate a lighter yellow and a darker blue. Therefore, the L*, a*, and b* values ​​can be adjusted depending on the use, purpose, etc. of the product to which the polyester resin is applied. Specifically, the polyester resin may have an L* value of 60 to 70, an a* value of -2.3 to -0.1, and a b* value of 0.5 to 8.5.

[0053] The intrinsic viscosity (25°C) of the above polyester resin may be 1.1 dl / g to 2.8 dl / g, for example, 1.2 dl / g to 2.5 dl / g. When the intrinsic viscosity (25°C) of the polyester resin is within the above range, the film processability is excellent, and as it has an appropriate viscosity, productivity and yield are improved, and biodegradability, mechanical properties, and color characteristics are excellent.

[0054] Below, a method for manufacturing the above polyester resin is described.

[0055] According to one embodiment, a polyester resin is manufactured through the steps of: reacting lactic acid in the presence of a first catalyst to produce lactide; reacting a furan dicarboxylic acid-based compound and an aliphatic diol-based compound in the presence of a second catalyst to produce a furan-based oligomer; subjecting the manufactured lactide to ring-opening polymerization in the presence of the first catalyst to produce a lactide oligomer; and introducing the furan-based oligomer into the manufactured lactide oligomer and reacting it in the presence of a second catalyst to produce a copolymer. The manufactured copolymer includes a structural unit represented by the aforementioned chemical formula 1.

[0056] According to one embodiment, when manufacturing a polymer from the polymerization of lactide, by polymerizing together a furan oligomer manufactured by the reaction of a furan dicarboxylic acid compound, which is a bio-derived raw material, and an aliphatic diol compound, the brittle properties of conventional polylactic acid (PLA) can be improved and biodegradability can be enhanced.

[0057] Lactide manufacturing

[0058] The production of lactide from lactic acid is carried out under a first catalyst.

[0059] The first catalyst may include a titanium (Ti)-based catalyst, a tin (Sn)-based catalyst, or a combination thereof, and is different from the second catalyst. For example, the first catalyst may include a tin (Sn)-based catalyst.

[0060] The titanium (Ti)-based catalyst may include, for example, titanium oxide, titanium butoxide, titanium alkoxide, titanium chelate, 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, a titanium dioxide-silicon dioxide copolymer, a titanium dioxide-zirconium dioxide copolymer, or a combination thereof.

[0061] The tin (Sn)-based catalyst may include, for example, tin oxalate, tin acetate, tin halide, dialkyl tin oxide, alkyl stannic acid, or a combination thereof.

[0062] In the step of producing lactide from lactic acid, an aliphatic diol compound may be added. The aliphatic diol compound may be added in an amount of 0.1 mol% to 2 mol% based on the amount of lactic acid added, for example, 0.2 mol% to 1.8 mol%. When a small amount of the aliphatic diol compound is added within the above range, the conversion rate into lactide increases, thereby obtaining lactide with high purity and yield.

[0063] The reaction for producing lactide from lactic acid can be carried out in a nitrogen (N2) atmosphere, at a temperature of 100°C to 250°C, for example, at a temperature of 120°C to 230°C, and for 30 minutes to 5 hours, for example, 30 minutes to 3 hours. When the reaction for producing lactide is carried out under the above conditions, the reaction yield is high, and ultimately, a polyester resin having excellent biodegradability, mechanical properties, and color characteristics can be produced.

[0064] Manufacturing of furan oligomers

[0065] The production of a furan oligomer by reaction of a furan dicarboxylic acid compound and an aliphatic diol compound is performed under a second catalyst.

[0066] The second catalyst may include a titanium (Ti)-based catalyst, a tin (Sn)-based catalyst, or a combination thereof, and is different from the first catalyst. For example, the second catalyst may include a titanium (Ti)-based catalyst.

[0067] Furan dicarboxylic acid compounds may include, but are not limited to, 2,5-furandicarboxylic acid.

[0068] The aliphatic diol compound may include, but is not limited to, substituted or unsubstituted C2 to C11 alkanediols. For example, the aliphatic diol compound may include C3 to C7 alkanediols, C3 to C5 alkanediols, and the like, and may include butanediol, for example.

[0069] The furan dicarboxylic acid compound and the aliphatic diol compound can react at a molar ratio of 1:1.1 to 1:1.8, for example, at a molar ratio of 1:1.2 to 1:1.7. When the furan dicarboxylic acid compound and the aliphatic diol compound are reacted within the molar ratio range, a polyester resin having improved biodegradability and excellent mechanical strength and color characteristics can be obtained.

[0070] After reacting a furan dicarboxylic acid compound and an aliphatic diol compound under a second catalyst, an additional step of removing a portion of the aliphatic diol compound may be performed. It is necessary to control the aliphatic diol compound to be 0.02 mol% or less based on the total amount of furan oligomers produced by the above reaction. By removing a portion of the excess aliphatic diol compound, the biodegradability and mechanical properties of the final polymerized polyester resin can be significantly improved.

[0071] The reaction of a furan dicarboxylic acid compound with an aliphatic diol compound, specifically an esterification reaction, can be performed in a nitrogen (N2) atmosphere, at a temperature of 160°C to 260°C, for example, at a temperature of 180°C to 220°C, and for 1 hour to 8 hours, for example, 1 hour to 6 hours. When the esterification reaction is performed under the above conditions, the reaction yield is high, and ultimately, a polyester resin having excellent biodegradability, mechanical properties, and color characteristics can be produced.

[0072] The number average molecular weight of the produced furan oligomer may be 1,000 g / mol to 3,000 g / mol, for example, 1,000 g / mol to 2,500 g / mol. When the number average molecular weight of the furan oligomer is within the above range, a polyester resin having excellent biodegradability, mechanical strength, and color characteristics can be produced.

[0073] Lactide oligomer manufacturing

[0074] The above-mentioned lactide is subjected to ring-opening polymerization under a first catalyst to produce a lactide oligomer. At this time, the first catalyst is the same as the first catalyst used in producing lactide from lactic acid.

[0075] A small amount of an aliphatic diol compound can be used as an initiator during the ring-opening polymerization of lactide. The initiator opens the lactide ring, causing a condensation reaction that increases the molecular weight, thereby producing a lactide oligomer.

[0076] When lactide, a furan dicarboxylic acid compound, and an aliphatic diol compound are reacted simultaneously, a reverse reaction from polylactide to lactide occurs due to the excess aliphatic diol compound, so polymerization does not occur. According to one embodiment, by obtaining a lactide oligomer with a molecular weight increased by ring-opening lactide to a certain amount, and then adding a furan oligomer to the lactide oligomer and polymerizing them together, a polyester resin, i.e., a copolymer including a structural unit represented by the above chemical formula 1, can be obtained.

[0077] Ring-opening polymerization of lactide can be performed in a nitrogen (N2) atmosphere, at a temperature of 100°C to 200°C, for example, at a temperature of 110°C to 1800°C, and for 1 to 8 hours, for example, 1 to 6 hours. When ring-opening polymerization of lactide is performed under the above conditions, the reaction yield is high, and ultimately, a polyester resin having excellent biodegradability, mechanical properties, and color characteristics can be produced.

[0078] The number average molecular weight of the lactide oligomer may be 5,000 g / mol to 10,000 g / mol, for example 5,000 g / mol to 9,000 g / mol. When the number average molecular weight of the lactide oligomer is within the above range, a polyester resin having excellent biodegradability, mechanical strength, and color properties can be produced.

[0079] Reaction of lactide oligomers and furan oligomers

[0080] A copolymer including a structural unit represented by the above chemical formula 1 is manufactured by adding the furan-based oligomer manufactured above to a lactide oligomer and reacting it under a second catalyst. At this time, the second catalyst is the same as the second catalyst used in manufacturing the furan-based oligomer.

[0081] The molar ratio of the first catalyst used in the production of the above lactide oligomer and the second catalyst used in the production of the above copolymer may be 1:10 to 10:1, for example, 1:9 to 9:1. When the molar ratio of the first catalyst and the second catalyst is within the above range, a polyester resin having excellent biodegradability, mechanical strength, and color characteristics can be produced.

[0082] In the production of the above copolymer, the lactide oligomer and the furan-based oligomer can react at a molar ratio of 50:1 to 1:50, for example, at a molar ratio of 1:9 to 9:1. When the lactide oligomer and the furan-based oligomer react within the molar ratio range, a polyester resin having excellent biodegradability, mechanical strength, and color characteristics can be produced.

[0083] The reaction of a lactide oligomer and a furan oligomer, specifically an esterification reaction, can be performed in a nitrogen (N2) atmosphere, at a temperature of 160°C to 260°C, for example, at a temperature of 180°C to 220°C, and for 1 hour to 8 hours, for example, 1 hour to 6 hours. When the esterification reaction is performed under the above conditions, a polyester resin having a high reaction yield and excellent biodegradability, mechanical properties, and color characteristics can be produced.

[0084] The implementation examples described above are described in more detail through the following examples. However, the following examples are for illustrative purposes only and do not limit the scope of the rights.

[0085] (Lactide manufacturing)

[0086] Manufacturing Example 1

[0087] 1000g of lactic acid was charged into an autoclave reactor for esterification reaction, and 10ppm (0.01g) of tin oxalate catalyst was added per 1000g of lactic acid. 1,4-butanediol was added at 1% mol (10g) to increase the conversion rate. After replacing with N2 five times, the stirrer was maintained at 60rpm and the temperature was increased to 150℃ for 40 minutes. The reaction was carried out by increasing the temperature to 170℃, 190℃, and 210℃ in a buffer tank until the effluent was more than 90% of the theoretical effluent. When the effluent was more than 90% completed, the buffer tank pipe was locked, the valve of the first product tank was opened, and the temperature was increased to 250℃ for 1 hour using a vacuum pump, while gradually converting the atmospheric pressure to vacuum. Afterwards, crude lactide was received from the first product tank through high vacuum until the vacuum level was reduced to 0.5 torr. When 0.5 torr was reached, the valves of the autoclave and the first product tank were closed, and the valves of the first product tank and the second product tank were opened. Then, the temperature of the first product tank was increased to 240°C under vacuum, and the stirrer rpm was maintained at 60 rpm. When the vacuum level of the first product tank reached 0.5 torr, the reaction was terminated, and 695 g of pure lactide (87% yield, 98.5% purity measured by GC-MS) was obtained from the second product tank.

[0088] Manufacturing Example 2

[0089] 1000g of lactic acid was charged into an autoclave reactor for esterification reaction, and 10ppm (0.01g) of tin oxalate catalyst was added per 1000g of lactic acid. After replacing with N2 5 times, the stirrer was maintained at 60rpm and the temperature was increased to 150℃ for 40 minutes. The reaction was carried out by increasing the temperature to 170℃, 190℃, and 210℃ until the effluent was more than 90% of the theoretical effluent in a buffer tank where the effluent could be checked. When more than 90% was completed, the buffer tank pipe was locked, the valve of the first product tank was opened, and then the temperature was increased to 250℃ for 1 hour using a vacuum pump, while gradually converting the atmospheric pressure to vacuum. Afterwards, crude lactide was received from the first product tank through high vacuum until the vacuum level was lowered to 0.5 torr. When 0.5 torr was reached, the valves of the autoclave and the first product tank were closed, and the valves of the first product tank and the second product tank were opened. Then, the temperature of the first product tank was increased to 240°C under vacuum, and the stirrer rpm was maintained at 60 rpm. When the vacuum level of the first product tank reached 0.5 torr, the reaction was terminated, and 559.9 g of pure lactide (70% yield, 94% purity measured by GC-MS) was obtained from the second product tank.

[0090] Manufacturing Example 3

[0091] 1000g of lactic acid was charged into an autoclave reactor for esterification reaction, and 10ppm (0.01g) of tin oxalate catalyst was added per 1000g of lactic acid. After replacing with N2 5 times, the stirrer was maintained at 60rpm and the temperature was increased to 150℃ for 40 minutes. The reaction was carried out by increasing the temperature to 170℃, 190℃, and 210℃ until the effluent was more than 90% of the theoretical effluent in a buffer tank where the effluent could be checked. When more than 90% was completed, the buffer tank pipe was locked, the valve of the first product tank was opened, and then the temperature was increased to 250℃ for 1 hour using a vacuum pump, while gradually converting the atmospheric pressure to vacuum. Afterwards, 735.98 g of lactide (92% yield, 91% purity measured by GC-MS) was obtained from the first product tank through high vacuum until the vacuum level was reduced to 0.5 torr.

[0092] (Manufacture of furan oligomers)

[0093] Manufacturing Example 4

[0094] In an autoclave reactor for esterification reaction, 742.5 g (4.75 mol) of 2,5-furan dicarboxylic acid (FDCA) and 1071 g (11.89 mol) of 1,4-butanediol (BDO) were charged to produce 1 kg of product, and 100 ppm (0.1 g) of tetrabutyl titanate (TBT) catalyst was charged per 1 kg of product. After replacing with N2 5 times, the stirrer was maintained at 60 rpm and the temperature was increased to 210℃ for 60 minutes. The reaction was carried out until more than 90% of the theoretical effluent was output in a buffer tank where the effluent could be checked. When more than 90% was completed, the temperature was increased to 260℃ for 1 hour using a vacuum pump connected to the buffer tank, while gradually converting the atmospheric pressure to vacuum. After removing the excess 1,4-butanediol through this process, the reaction was terminated. The produced furan oligomer (FDCA-BDO) was drained into a SUS tray, and a furan oligomer with a yield of 91% (910 g, purity measured by LC-MS, excess BDO less than 100 ppm) was obtained.

[0095] Manufacturing Example 5

[0096] In an autoclave reactor for esterification reaction, 742.5 g (4.75 mol) of 2,5-furan dicarboxylic acid (FDCA) and 1071 g (11.89 mol) of 1,4-butanediol (BDO) were charged to produce 1 kg of product, and 100 ppm (0.1 g) of tetrabutyl titanate (TBT) catalyst was charged per 1 kg of product. After replacing with N2 5 times, the stirrer was maintained at 60 rpm and the temperature was increased to 210℃ for 60 minutes. The reaction was continued until the theoretical effluent amount was 90% or more in a buffer tank where the effluent could be checked. The reaction was terminated when it was completed by more than 90%. The generated furan oligomer (FDCA-BDO) was drained into a SUS tray, and a furan oligomer with a yield of 101% (1010 g, purity measured by LC-MS, including excess BDO at the level of 10000 ppm) was obtained.

[0097] (Manufacture of polyester resin)

[0098] Example 1

[0099] 18.3 g (0.25 mol) of lactide manufactured in Manufacturing Example 1 was placed in an autoclave, and after N2 purging 5 times, the temperature was raised to 120°C for 60 minutes. When it reached 120°C, 10 ml of toluene and 10 ppm of tin oxalate catalyst were added to the flask. The temperature was raised to 160°C, and it was confirmed that the lactide was ring-opened and the viscosity increased through the polymerization process. When the torque reached 10 Ncm, it was placed in the autoclave together with 481.7 g (2.29 mol) of the furan oligomer (FDCA-BDO) manufactured in Manufacturing Example 4 and 10 ppm of tetrabutyl titanate (TBT) catalyst. The temperature was raised to 220°C for 1 hour while gradually replacing the atmospheric pressure with a vacuum. When the temperature reached 220℃, the reaction was carried out in a high vacuum of 0.5 Torr or less, and when the desired torque was reached, the reaction was terminated to produce a polyester resin. The produced polymer was drained into a water bath and the polymer properties were evaluated.

[0100] Example 2

[0101] A polyester resin was manufactured in the same manner as in Example 1, except that 67.9 g (0.94 mol) of lactide manufactured in Manufacturing Example 1 and 462.4 g (2.2 mol) of furan-based oligomer (FDCA-BDO) manufactured in Manufacturing Example 4 were used.

[0102] Example 3

[0103] A polyester resin was manufactured in the same manner as in Example 1, except that 134.2 g (1.86 mol) of lactide manufactured in Manufacturing Example 1 and 391.5 g (1.86 mol) of furan-based oligomer (FDCA-BDO) manufactured in Manufacturing Example 4 were used.

[0104] Example 4

[0105] A polyester resin was manufactured in the same manner as in Example 1, except that 230.6 g (3.2 mol) of lactide manufactured in Manufacturing Example 1 and 288.3 g (1.37 mol) of furan-based oligomer (FDCA-BDO) manufactured in Manufacturing Example 4 were used.

[0106] Example 5

[0107] A polyester resin was manufactured in the same manner as in Example 1, except that 383.8 g (5.33 mol) of lactide manufactured in Manufacturing Example 1 and 124.4 g (0.59 mol) of furan-based oligomer (FDCA-BDO) manufactured in Manufacturing Example 4 were used.

[0108] Example 6

[0109] A polyester resin was prepared in the same manner as in Example 5, except that the TBT catalyst was changed to 100 ppm.

[0110] Example 7

[0111] A polyester resin was manufactured in the same manner as in Example 5, except that 1000 ppm of glycerin was additionally added as a crosslinking agent.

[0112] Comparative Example 1

[0113] 100 g (0.69 mol) of the lactide produced in Manufacturing Example 1 was placed in a 250 ml 3-neck flask, equipped with a thermometer, a stirrer, and a Dean Stark, and after N2 purging 5 times, the temperature was raised to 120°C for 40 minutes. When it reached 120°C, 10 ml of toluene and 10 ppm of tin oxalate catalyst were added. The temperature was raised to 210°C for 1 hour while gradually replacing the atmospheric pressure with vacuum. When it reached 210°C, the reaction was carried out in a high vacuum of 0.5 Torr or less, and the reaction was terminated when the desired torque was reached, thereby producing a polyester resin. The produced polymer was drained into a water bath and the polymer properties were evaluated.

[0114] Comparative Example 2

[0115] A polyester resin was manufactured in the same manner as in Comparative Example 1, except that 100 g (0.69 mol) of lactide manufactured in Manufacturing Example 2 was added instead of the lactide manufactured in Manufacturing Example 1.

[0116] Comparative Example 3

[0117] A polyester resin was manufactured in the same manner as in Comparative Example 1, except that 100 g (0.69 mol) of lactide manufactured in Manufacturing Example 3 was added instead of the lactide manufactured in Manufacturing Example 1.

[0118] Comparative Example 4

[0119] 100 g (0.47 mol) of the furan oligomer (FDCA-BDO) manufactured in Manufacturing Example 4 was placed in a 250 ml 3-neck flask, equipped with a thermometer, a stirrer, and a Dean Stark, and after N2 purging 5 times, the temperature was raised to 210°C for 60 minutes. When it reached 210°C, a solution in which 10 ml of 1,4-butanediol (BDO) was diluted with 10 ppm of tetrabutyl titanate (TBT) catalyst was added to the flask. The temperature was raised to 260°C for 1 hour while gradually replacing the atmospheric pressure with a vacuum. When it reached 260°C, the reaction was carried out in a high vacuum of 0.5 Torr or less, and the reaction was terminated when the desired torque was reached, thereby manufacturing a polyester resin. The manufactured polymer was drained into a water bath and the polymer properties were evaluated.

[0120] Comparative Example 5

[0121] A polyester resin was manufactured in the same manner as in Comparative Example 4, except that 100 g (0.47 mol) of the furan oligomer (FDCA-BDO) manufactured in Manufacturing Example 5 was added instead of the furan oligomer manufactured in Manufacturing Example 4.

[0122] Comparative Example 6

[0123] A 3-neck flask equipped with a thermometer, a stirrer, and a Dean Stark flask was charged with 49.53 g (0.31 mol) of 2,5-furan dicarboxylic acid (FDCA), 71.6 g (0.79 mol) of 1,4-butanediol (BDO), and 22.9 g (0.31 mol) of the lactide prepared in Manufacturing Example 1. After five N2 purges, the temperature was raised to 190°C for 40 minutes. Upon reaching 190°C, the esterification reaction was performed until the FDCA dissolved in BDO and a clear solution was formed. Thereafter, a solution in which 10 ppm of a tin oxalate catalyst was diluted in 10 ml of toluene and 10 ppm of a tetrabutyl titanate (TBT) catalyst was diluted in 10 ml of 1,4-butanediol (BDO) was added. The temperature was increased to 220°C for 1 hour while gradually replacing atmospheric pressure with vacuum. Upon reaching 220°C, the reaction was carried out in a high vacuum of 0.5 Torr or less, and when the desired torque was reached, the reaction was terminated to produce a polyester resin. The produced polymer was drained into a water bath and the polymer properties were evaluated.

[0124] Comparative Example 7

[0125] A polyester resin was prepared in the same manner as in Example 1, except that the tetrabutyl titanate (TBT) catalyst was not used.

[0126] Comparative Example 8

[0127] A polyester resin was prepared in the same manner as in Example 1, except that the tin oxalate catalyst was not used.

[0128] Reference Example 1

[0129] 26.8 g (0.37 mol) of lactide manufactured in Manufacturing Example 2 was placed in a 250 ml 3-neck flask, equipped with a thermometer, a stirrer, and a Dean Stark, and after N2 purging 5 times, the temperature was increased to 120°C for 60 minutes. When it reached 120°C, 10 ml of toluene and 10 ppm of tin oxalate catalyst were added. The temperature was increased to 160°C, and it was confirmed that the lactide opened and the viscosity increased through the polymerization process. When the stirrer torque reached 10 Ncm, 78.3 g (0.37 mol) of the furan oligomer (FDCA-BDO) manufactured in Manufacturing Example 5 and 10 ppm of tetrabutyl titanate (TBT) catalyst were added to the flask. The temperature was raised to 220°C for 1 hour while gradually replacing atmospheric pressure with vacuum. Upon reaching 220°C, the reaction was carried out in a high vacuum of 0.5 Torr or less, and when the desired torque was reached, the reaction was terminated to produce a polyester resin. The produced polymer was drained into a water bath and its properties were evaluated.

[0130] Reference Example 2

[0131] A polyester resin was manufactured in the same manner as in Reference Example 1, except that the lactide manufactured in Manufacturing Example 3 was used instead of the lactide manufactured in Manufacturing Example 2.

[0132]

[0133] Evaluation 1: Evaluation of the physical properties of polyester resin

[0134] The following physical properties were measured for the polyester resins manufactured in Examples 1 to 7, Comparative Examples 1 to 8, and Reference Examples 1 and 2, and the results are shown in Table 1 below.

[0135] - Randomness: 0.1 mg of polyester resin sample was placed in a 10 ml vial and dissolved in CF3COOD solvent at a concentration of 10 wt% at room temperature. 1H NMR was measured, and the furan peak observed around 7.2 ppm to 7.4 ppm was integrated by 2 to calculate the area of ​​the butylene structural unit from 4.1 ppm to 4.5 ppm. This integral value was substituted into the following mathematical formula to obtain the randomness.

[0136]

[0137] - Glass transition temperature (Tg): Measured using TA Instrument's DSC under conditions of N2, 20 psi, and 20°C / min from room temperature to 300°C.

[0138] - Terminal acid value: The titration method according to ASTM D7409 was modified to suit the copolymer and measured. The solvent for dissolving the polymer was a mixture of trichloroethylene (TCE) and phenol in a weight ratio of 1:1, and it was dissolved in a 100℃ oil bath at 5% wt / wt. The indicator was 0.5 mg of bromocresol green dissolved in 1 ml of ethanol, and the terminal acid value was measured using 0.05 N KOH contained in ethanol as the monomer point titrant.

[0139] - Intrinsic viscosity (IV): 0.5 g of polyester resin sample was dissolved in 10 ml of a solution of phenol and tetrachloroethane (volume ratio 1:1) and measured at 25°C using an Ostwald viscometer.

[0140] - Color characteristics: L*, a*, and b* values ​​were measured using a Chip colorimeter from Nippon Denshoku (sa-4000). Specifically, 2 g of a polyester resin sample was dissolved in 20 ml of hexafluoroisopropanol (HFIP) (0.1 g / ml in HFIP). The colorimetric value of the sample solution was measured using a Tuartz cell dedicated to solution colorimetric measurement using a Konica Minolta CM-3700A device.

[0141] - Biodegradability: Evaluated for 45 days under composting conditions according to ISO14855-1.

[0142] - Tensile modulus, tensile strength, and elongation: ASTM D638-V Type specimens were prepared from polyester resin samples using a microcompounder extruder at an extrusion temperature of 120°C to 160°C and a screw speed of 100 rpm to 120 rpm. The manufactured polyester resin specimens were mounted in the LD direction using vice grips under a universal testing machine UTM 5566A (Instron). The specimens were elongated at a rate of 5 mm / min at room temperature until fracture. The strength at the point of fracture was defined as the tensile strength, the length increased was defined as the elongation, and the slope of the load with respect to the initial deformation was defined as the tensile modulus.

[0143] Table 1

[0144]

[0145] - F Oligo. represents furan oligomer (FDCA-BDO).

[0146] - Tin. stands for tin oxalate.

[0147] Through the above Table 1, it can be seen that the polyester resins manufactured according to Examples 1 to 7 are copolymers containing residues derived from furan oligomers and residues derived from lactide oligomers, and are superior in biodegradability, mechanical properties, and color characteristics compared to Comparative Examples 1 to 8.

[0148] Specifically, it can be seen that Comparative Examples 1 to 3, which were manufactured by polymerizing only lactide without a furan-based oligomer, do not obtain a copolymer according to one embodiment, and that the biodegradability and mechanical properties are deteriorated. In addition, it can be seen that Comparative Examples 4 and 5, which were manufactured by polymerizing only a furan-based oligomer without lactide, do not obtain a copolymer according to one embodiment, and that the biodegradability and mechanical properties are deteriorated. In addition, it can be seen that Comparative Example 6, which was polymerized by simultaneously reacting furan dicarboxylic acid, butanediol, and lactide, has a very low intrinsic viscosity and thus polymerization does not occur. In addition, it can be seen that the polyester resin of Comparative Example 7, which was manufactured without using a catalyst in the reaction of the furan-based oligomer and the lactide oligomer, and the polyester resin of Comparative Example 8, which was manufactured without using a catalyst in the ring-opening polymerization of lactide, both have low intrinsic viscosity and deteriorated mechanical properties.

[0149] Although the preferred embodiments of the present invention 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 concept of the present invention defined in the following claims also fall within the scope of the present invention.

Claims

1. A polyester resin comprising a structural unit represented by the following chemical formula 1. [Chemical Formula 1] (In the above chemical formula 1, R 1 Inland R 10 are each independently a hydrogen atom, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C3 to C20 cycloalkenyl group, a substituted or unsubstituted C3 to C20 cycloalkynyl group, or a substituted or unsubstituted C6 to C30 aryl group, n is an integer from 1 to 10, m is an integer from 1 to 10, x is an integer between 2 and 100, y is an integer between 2 and 100.) 2. In paragraph 1, A polyester resin wherein the ratio of x and y in the chemical formula 1 is 50:1 to 1:

50.

3. In paragraph 1, The above polyester resin is a polyester resin having a randomness of more than 1 and less than or equal to 1.1 as determined by NMR analysis.

4. In paragraph 1, The above polyester resin contains a carboxyl group at the terminal, A polyester resin having an acid value of the carboxyl group at the terminal of the above-mentioned terminal of 10 eq / ton to 25 eq / ton.

5. In paragraph 1, A polyester resin having a number average molecular weight of 47,000 g / mol to 147,000 g / mol.

6. In paragraph 1, A polyester resin having a glass transition temperature (Tg) of 30°C to 70°C.

7. In paragraph 1, The above polyester resin is a polyester resin having an L* value of 60 to 80, an a* value of -2.5 to 0, and a b* value of 0.1 to 9 according to the CIE1976 L*a*b* colorimetric system.

8. In paragraph 1, A polyester resin having an intrinsic viscosity (25°C) of 1.1 dl / g to 2.8 dl / g.

9. A method for producing a polyester resin according to any one of claims 1 to 8, A step of producing lactide by reacting lactic acid in the presence of a first catalyst; A step of producing a furan oligomer by reacting a furan dicarboxylic acid compound and an aliphatic diol compound in the presence of a second catalyst; A step of producing a lactide oligomer by ring-opening polymerizing the above lactide under a first catalyst; and It comprises a step of producing a copolymer by adding the furan-based oligomer to the lactide oligomer and reacting it under a second catalyst. A method for producing a polyester resin, wherein the first catalyst and the second catalyst include a titanium (Ti)-based catalyst, a tin (Sn)-based catalyst, or a combination thereof, and the first catalyst and the second catalyst are different from each other.

10. In Article 9, A method for producing a polyester resin, wherein the first catalyst comprises a tin (Sn)-based catalyst and the second catalyst comprises a titanium (Ti)-based catalyst.

11. In paragraph 9, A method for producing a polyester resin, wherein the molar ratio of the first catalyst in the step of producing the lactide oligomer and the second catalyst in the step of producing the copolymer is 1:10 to 10:

1.

12. In Article 9, A method for producing a polyester resin, wherein the step of producing the above lactide includes a step of adding an aliphatic diol compound.

13. In paragraph 9, The above furan dicarboxylic acid compound contains 2,5-furandicarboxylic acid, The above aliphatic diol compound is a method for producing a polyester resin containing butanediol.

14. In paragraph 9, A method for producing a polyester resin, wherein in the step of producing the furan-based oligomer, the furan dicarboxylic acid-based compound and the aliphatic diol-based compound react at a molar ratio of 1:1.1 to 1:1.

8.

15. In paragraph 9, A method for producing a polyester resin, wherein the step of producing the furan-based oligomer includes a step of partially removing the aliphatic diol-based compound.

16. In paragraph 9, A method for producing a polyester resin wherein the number average molecular weight of the furan-based oligomer is 1,000 g / mol to 3,000 g / mol.

17. In paragraph 9, A method for producing a polyester resin wherein the number average molecular weight of the above lactide oligomer is 5,000 g / mol to 10,000 g / mol.

18. In paragraph 9, A method for producing a polyester resin, wherein, in the step of producing the copolymer, the lactide oligomer and the furan-based oligomer are reacted at a molar ratio of 50:1 to 1:50.

Images