Biodegradable polyester resin composition and biodegradable molded article containing the same

Abstract

An example provides a biodegradable polyester resin composition containing a polyester resin including a diol, an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid, and having a first weight swelling ratio of 4% to 20%. The first weight swelling ratio is a value obtained by dividing the difference between the weight after immersion in ethanol and the initial weight by the initial weight.

Description

Technical Field

[0001] The examples relate to a biodegradable polyester resin composition and a biodegradable molded article containing the same.

Background Art

[0002] In recent years, as the concern about environmental problems has increased, solutions to the treatment problems of various daily necessities, especially disposable products, have been demanded. Specifically, polymer materials are inexpensive and have excellent properties such as processability, and are widely used in manufacturing various products such as films, fibers, packaging materials, bottles, and containers. However, when the life of the used products ends, harmful substances are emitted during incineration, and it takes hundreds of years for some types to be completely decomposed naturally, which has the disadvantage.

[0003] To overcome the limitations of these polymers, research on biodegradable polymers that can be decomposed within a short time has been actively conducted. As biodegradable polymers, polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), etc. are used.

[0004] These biodegradable resin compositions are disclosed in Korean Patent Publication No. 2012-0103158, etc.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The examples aim to provide a biodegradable polyester resin composition having improved moisture resistance and improved printability, and a biodegradable molded article containing the same.

Means for Solving the Problems

[0006] The biodegradable polyester resin composition according to the embodiment includes a polyester resin containing a diol, an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid, and has a first weight swelling ratio of 4% to 20%. The first weight swelling ratio is measured by the following measurement method.

[0007] [Measurement method] The biodegradable polyester resin composition is dried at a temperature of 80 °C, placed in a stainless-steel frame, compressed at a temperature of 210 °C and a pressure of 10 MPa for 3 minutes to produce a polyester sheet having a thickness of 300 μm. The initial weight of the polyester sheet and the weight after the polyester sheet is immersed in ethanol at room temperature for 2 hours are measured. The first weight swelling ratio is the value obtained by dividing the difference between the weight after immersion and the initial weight by the initial weight.

[0008] In the biodegradable polyester resin composition according to one embodiment, the volume swelling ratio may be 5% to 20%, and the volume swelling ratio may be measured by the following measurement method.

[0009] [Measurement method] The initial volume of the polyester sheet and the volume after the polyester sheet is immersed in ethanol at room temperature for 2 hours are measured. The volume swelling ratio is the value obtained by dividing the difference between the volume after immersion and the initial volume by the initial volume.

[0010] The biodegradable polyester resin composition according to one embodiment may contain a silicon element in a content of about 0.1 ppm to 1000 ppm.

[0011] In one embodiment, the water contact angle on the surface of the polyester sheet may be 45° to 85°.

[0012] In one embodiment, the polarity on the surface of the polyester sheet may be 3 mN / m to 5 mN / m.

[0013] The biodegradable polyester resin composition according to one embodiment may further contain a metal.

[0014] In one embodiment, the metal contains iron element, and the ratio of the iron element to the silicon element may be 0.1 to 0.7.

[0015] In the biodegradable polyester resin composition according to one embodiment, the degree of hydrolysis after one week is 35% to 60%, and the degree of hydrolysis after three weeks is 85% or more. The degree of hydrolysis after one week and the degree of hydrolysis after three weeks may be measured by the following measurement method.

[0016] [Measurement method] The degree of hydrolysis after one week is the reduction rate of the number average molecular weight of the biodegradable polyester resin composition with respect to the initial value when the biodegradable polyester resin composition is placed for one week under the high temperature and high humidity conditions of a temperature of 80°C and a humidity of 100%. The degree of hydrolysis after three weeks is the reduction rate of the number average molecular weight of the biodegradable polyester resin composition with respect to the initial value when the biodegradable polyester resin composition is placed for three weeks under the high temperature and high humidity conditions of a temperature of 80°C and a humidity of 100%.

[0017] In the biodegradable polyester resin composition according to one embodiment, the second weight swelling ratio is 4% to 20%, and the second weight swelling ratio may be measured by the following measurement method.

[0018] [Measurement method] The initial weight of the polyester sheet and the weight of the polyester sheet after being immersed in ethanol at room temperature for 24 hours are measured. The first weight swelling ratio is the value obtained by dividing the difference between the weight after immersion and the initial weight by the initial weight.

[0019] In one embodiment, the difference between the first weight swelling ratio and the second swelling ratio may be 5% or less.

[0020] The biodegradable polyester resin composition according to the example includes a polyester resin containing a diol, an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid, and has a wet hardness reduction rate of 15% or less. The wet hardness reduction rate is measured by the following measurement method.

[0021] [Measurement method] The biodegradable polyester resin composition is used to produce a polyester block having a thickness of 2.5 mm. The initial hardness of the polyester block and the wet hardness after the polyester block is immersed in water at 30°C for 24 hours are measured. The wet hardness reduction rate is the value obtained by dividing the difference between the initial hardness and the wet hardness by the initial hardness.

[0022] In the biodegradable resin composition according to one example, the initial hardness may be 30 to 45 in Shore D hardness, and the wet hardness may be 28 to 43 in Shore D hardness.

[0023] In the biodegradable polyester resin composition according to one example, the wet hardness reduction rate may be 12% or less.

[0024] In the biodegradable polyester resin composition according to one example, the content of silicon element may be 0.1 ppm to 1000 ppm.

[0025] In the biodegradable polyester resin composition according to one example, the water contact angle on the surface of the polyester block may be 45° to 85°.

[0026] In the biodegradable polyester resin composition according to one example, the difference between the wet hardness after immersion in water at 30°C for 1 hour and the wet hardness after immersion in water at 30°C for 24 hours may be 10% or less based on the initial hardness.

[0027] In the biodegradable polyester resin composition according to an embodiment, the difference between the wet hardness after immersion in water at 30°C for 24 hours and the wet hardness after immersion in water at 70°C for 24 hours may be 10% or less based on the initial hardness.

[0028] The biodegradable molded article according to the embodiment contains a polyester resin containing a diol, an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid, and has a weight swelling ratio of 4% to 20%. The weight swelling ratio may be measured by the following measurement method.

[0029] [Measurement method] The molded article is manufactured into a sample having a thickness of about 300 μm, the initial weight of the sample and the weight after the sample is immersed in ethanol at room temperature for 2 hours are measured, and the weight swelling ratio is the value obtained by dividing the difference between the weight after immersion and the initial weight by the initial weight.

[0030] In the biodegradable molded article according to an embodiment, the wet hardness reduction rate is 15% or less, and the wet hardness reduction rate may be measured by the following measurement method.

[0031] [Measurement method] The biodegradable molded article is processed to produce a block having a thickness of 2.5 mm, the initial hardness of the block and the wet hardness after the block is immersed in water at 30°C for 24 hours are measured, and the wet hardness reduction rate is the value obtained by dividing the difference between the initial hardness and the wet hardness by the initial hardness.

[0032] The biodegradable molded article according to an embodiment contains an iron element and a silicon element, and the mass ratio of the iron element to the silicon element may be 0.1 to 0.7. [Advantages of the Invention]

[0033] In the biodegradable polyester resin composition according to the example, the first weight swelling ratio is 4% to 20%. The biodegradable polyester resin composition according to the example may have an appropriate swelling ratio in an organic solvent such as ethanol. That is, the biodegradable polyester resin composition according to the example may have appropriate solvent properties with respect to the organic solvent.

[0034] As a result, molded articles such as films produced from the biodegradable polyester resin composition according to the example can be easily printed with the ink containing the organic solvent. That is, the ink can appropriately penetrate into the surface of the molded article containing the biodegradable polyester resin composition according to the example by the organic solvent. As a result, the biodegradable polyester resin composition according to the example may have improved printability.

[0035] Also, in the biodegradable polyester resin composition according to the example, the wet hardness reduction rate is 15% or less. As a result, the biodegradable polyester resin composition according to the example may have high moisture resistance. The biodegradable polyester resin composition according to the example can maintain high mechanical properties even when exposed to water or in a high-humidity environment.

[0036] The biodegradable polyester resin composition according to the example may have appropriate hydrophobicity. As a result, the biodegradable polyester resin composition according to the example may have high moisture resistance. The biodegradable polyester resin composition according to the example can maintain high mechanical properties even when exposed to water or in a high-humidity environment.

[0037] As a result, when the biodegradable polyester resin composition according to the example is used for packaging foods with a high moisture content, etc., it may have little change in mechanical properties.

[0038] Also, the biodegradable polyester resin composition according to the example may have hydrophobic properties. As a result, the biodegradable polyester resin composition according to the example can absorb a small amount of moisture in the air. As a result, the biodegradable polyester resin composition according to the example may have improved storage stability.

[0039] The biodegradable polyester resin composition according to the example may contain a silicone-based hydrolysis inhibitor. As a result, the biodegradable polyester resin composition according to the example may have improved hydrolysis resistance. Further, the silicone-based hydrolysis inhibitor can function as a coupling agent that couples the polymer resin contained in the polycondensation composition.

[0040] As a result, the silicone-based hydrolysis inhibitor can improve the degree of polymerization of the biodegradable polyester resin composition according to the example.

[0041] As a result, the biodegradable polyester resin composition according to the example has improved physical properties during the actual use period and can be easily biodegraded after use.

[0042] The biodegradable polyester resin composition according to the example can be efficiently applied to packaging films and the like. That is, the film produced from the biodegradable polyester resin composition according to the example can be used for normal applications such as packaging. At this time, the biodegradable polyester resin composition according to the example may have a low degree of hydrolysis initially, and within the normal use period of the user, the biodegradable polyester film can maintain mechanical and chemical physical properties to a certain extent or more.

[0043] At the same time, since the biodegradable polyester resin composition according to the example has a high degree of biodegradability, the film produced from the biodegradable polyester resin composition according to the example can be easily decomposed when discarded after use.

Brief Description of the Drawings

[0044]

Figure 1

Figure 2

Mode for Carrying Out the Invention

[0045] Hereinafter, the invention will be described in detail with reference to specific examples. The specific examples are not limited to the content disclosed below, and can be modified into various forms as long as the gist of the invention remains unchanged.

[0046] In this specification, when a certain part "includes" a certain component, this means that, unless otherwise stated, it does not exclude other components, and may further include other components.

[0047] Also, it should be understood that any numerical range indicating physical property values, dimensions, etc. of the components described in this specification is modified by the term "about" in all cases unless otherwise specified.

[0048] Terms such as first, second, primary, secondary, etc. in this specification are used to describe various components, and the above components are not limited by the above terms. The above terms are used only for the purpose of distinguishing one component from another.

[0049] The biodegradable polyester resin composition according to an example includes a biodegradable polyester resin. The biodegradable polyester resin composition according to an example may include the biodegradable polyester resin alone or together with other resins or additives.

[0050] The biodegradable polyester resin contains a diol, an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid. The biodegradable polyester resin contains a diol residue, an aromatic dicarboxylic acid residue, and an aliphatic dicarboxylic acid residue. The diol residue is derived from the diol, the aromatic dicarboxylic acid residue is derived from the aromatic dicarboxylic acid, and the aliphatic dicarboxylic acid residue is derived from the aliphatic dicarboxylic acid. The biodegradable polyester resin contains a diol component, an aromatic dicarboxylic acid component, and an aliphatic dicarboxylic acid component. Similarly, the diol component may be derived from the diol, the aromatic dicarboxylic acid component may be derived from the aromatic dicarboxylic acid, and the aliphatic dicarboxylic acid component may be derived from the aliphatic dicarboxylic acid.

[0051] In the description of the biodegradable polyester resin composition according to the examples, the diol residue may be represented by the diol. In the biodegradable polyester resin, the dicarboxylic acid residue may be represented by the dicarboxylic acid. Further, the residue may be represented by the component.

[0052] The diol may be an aliphatic diol. The diol may be a bio-derived diol. The diol may be at least one selected from the group consisting of ethanediol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 1,2-butanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,6-hexanediol, 2-ethyl-1,3-hexanediol, 2,4-dimethyl-2-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,6-hexanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, and 1,12-octadecanediol, or derivatives thereof.

[0053] The diol may be at least one selected from the group consisting of 1,4-butanediol, 1,2-ethanediol, 1,3-propanediol, diethylene glycol, neopentyl glycol, or derivatives thereof.

[0054] The diol may be at least one selected from the group consisting of 1,4-butanediol, 1,2-ethanediol, 1,3-propanediol, or derivatives thereof.

[0055] The diol may contain 1,4-butanediol or a derivative thereof.

[0056] The aromatic dicarboxylic acid may be at least one selected from the group consisting of phthalic acid, terephthalic acid, isophthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, anthracenedicarboxylic acid, phenanthrenedicarboxylic acid, or derivatives thereof.

[0057] The aromatic dicarboxylic acid may be at least one selected from the group consisting of terephthalic acid, dimethyl terephthalate, 2,6-naphthalenedicarboxylic acid, isophthalic acid, or derivatives thereof.

[0058] The aromatic dicarboxylic acid may contain terephthalic acid, dimethyl terephthalate, or derivatives thereof.

[0059] The aliphatic dicarboxylic acid may be at least one selected from the group consisting of oxalic acid, malonic acid, succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, or derivatives thereof.

[0060] The aliphatic dicarboxylic acid may be at least one selected from the group consisting of adipic acid, succinic acid, sebacic acid, or derivatives thereof.

[0061] The aliphatic dicarboxylic acid may contain adipic acid or a derivative thereof.

[0062] In the biodegradable polyester resin, the molar ratio of the total diol residues containing the diol to the total dicarboxylic acid residues containing the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid may be about 1:0.9 to about 1:1.1. The molar ratio of the total diol residues to the total dicarboxylic acid residues may be about 1:0.95 to about 1:1.05.

[0063] In the biodegradable polyester resin, the molar ratio of the aromatic dicarboxylic acid residue to the aliphatic dicarboxylic acid residue may be about 3:7 to about 7:3. In the biodegradable polyester resin, the molar ratio of the aromatic dicarboxylic acid residue to the aliphatic dicarboxylic acid residue may be about 3.3:6.7 to about 6.7:3.3. In the biodegradable polyester resin, the molar ratio of the aromatic dicarboxylic acid residue to the aliphatic dicarboxylic acid residue may be about 4:6 to about 6:4. In the biodegradable polyester resin, the molar ratio of the aromatic dicarboxylic acid residue to the aliphatic dicarboxylic acid residue may be about 4.2:5.8 to about 5:5.

[0064] The biodegradable polyester resin may contain diol residues derived from 1,4-butanediol in a content of about 90 mol% or more based on the total diol. The biodegradable polyester resin may contain diol residues derived from 1,4-butanediol in a content of about 95 mol% or more based on the total diol. The biodegradable polyester resin may contain diol residues derived from 1,4-butanediol in a content of about 98 mol% or more based on the total diol.

[0065] The biodegradable polyester resin may contain aromatic dicarboxylic acid residues derived from terephthalic acid or dimethyl terephthalate in an amount of about 30 mol% to about 70 mol% based on the total dicarboxylic acid. The biodegradable polyester resin may contain aromatic dicarboxylic acid residues derived from terephthalic acid or dimethyl terephthalate in an amount of about 35 mol% to about 65 mol% based on the total dicarboxylic acid. The biodegradable polyester resin may contain dicarboxylic acid residues derived from terephthalic acid or dimethyl terephthalate in an amount of about 40 mol% to about 59 mol% based on the total dicarboxylic acid. The biodegradable polyester resin may contain aromatic dicarboxylic acid residues derived from terephthalic acid or dimethyl terephthalate in an amount of about 43 mol% to about 53 mol% based on the total dicarboxylic acid.

[0066] The biodegradable polyester resin may contain aliphatic dicarboxylic acid residues derived from adipic acid in an amount of about 30 mol% to about 70 mol% based on the total dicarboxylic acid. The biodegradable polyester resin may contain aliphatic dicarboxylic acid residues derived from adipic acid in an amount of about 35 mol% to about 65 mol% based on the total dicarboxylic acid. The biodegradable polyester resin may contain aliphatic dicarboxylic acid residues derived from adipic acid in an amount of about 41 mol% to about 60 mol% based on the total dicarboxylic acid. The biodegradable polyester resin may contain aliphatic dicarboxylic acid residues derived from adipic acid in an amount of about 47 mol% to about 57 mol% based on the total dicarboxylic acid.

[0067] Further, the biodegradable polyester resin may contain a first block and a second block. The biodegradable polyester resin may have a molecular structure in which the first block and the second block are alternately bonded.

[0068] The first block may contain the diol residue and the aromatic dicarboxylic acid residue. The first block may be formed by an esterification reaction of the diol and the aromatic dicarboxylic acid. The first block may contain only the diol residue and the aromatic dicarboxylic acid residue. The first block may contain only the repeating units formed by the esterification reaction of the diol and the aromatic dicarboxylic acid. That is, the first block may mean the sum of the repeating units of the diol and the aromatic dicarboxylic acid before binding to the aliphatic dicarboxylic acid.

[0069] The second block may contain the diol residue and the aliphatic dicarboxylic acid residue. The second block may be formed by an esterification reaction of the diol and the aliphatic dicarboxylic acid. The second block may contain only the diol residue and the aliphatic dicarboxylic acid residue. The second block may contain only the repeating units formed by the esterification reaction of the diol and the aliphatic dicarboxylic acid. That is, the second block may mean the sum of the repeating units of the diol and the aliphatic dicarboxylic acid before binding to the aromatic dicarboxylic acid.

[0070] In the biodegradable polyester resin, the ratio (X / Y) of the number (X) of the first blocks to the number (Y) of the second blocks may be from about 0.5 to about 1.5. In the biodegradable polyester resin, the ratio (X / Y) of the number (X) of the first blocks to the number (Y) of the second blocks may be from about 0.6 to about 1.4. In the biodegradable polyester resin, the ratio (X / Y) of the number (X) of the first blocks to the number (Y) of the second blocks may be from about 0.7 to about 1.3. In the biodegradable polyester resin, the ratio (X / Y) of the number (X) of the first blocks to the number (Y) of the second blocks may be from about 0.75 to about 1.2. Also, in the biodegradable polyester resin, the ratio (X / Y) of the number (X) of the first blocks to the number (Y) of the second blocks may be 0.8 to 1.1. The number of the first blocks may be even smaller than the number of the second blocks.

[0071] The number of the first blocks may be from about 30 to about 300. The number of the first blocks may be from about 40 to about 250. The number of the first blocks may be from about 50 to about 220. The number of the first blocks may be from about 60 to about 200. The number of the first blocks may be from about 70 to about 200. The number of the first blocks may be from about 75 to about 200.

[0072] The number of the first blocks may vary depending on the content of the aromatic dicarboxylic acid, the molecular weight of the biodegradable polyester resin, and the crosslinking ratio described below. That is, the number of the first blocks may increase as the molar ratio of the aromatic dicarboxylic acid increases, as the molecular weight of the biodegradable polyester resin increases, and as the crosslinking ratio described below increases.

[0073] The number of the second blocks may be about 30 to about 300. The number of the second blocks may be about 40 to about 250. The number of the second blocks may be about 50 to about 220. The number of the second blocks may be about 60 to about 200. The number of the second blocks may be about 70 to about 200. The number of the second blocks may be about 75 to about 200.

[0074] When the biodegradable polyester resin contains the first block and the second block within the above ranges, the biodegradable polyester resin composition according to the examples may have appropriate mechanical strength and appropriate biodegradability. Further, when the biodegradable polyester resin contains the first block and the second block within the above ranges, the biodegradable polyester resin composition according to the examples may have improved flexibility and improved rigidity. As a result, the biodegradable polyester resin composition according to the examples can be easily used for injection molded products and the like. Further, when the biodegradable polyester resin contains the first block and the second block within the above ranges, the biodegradable polyester resin composition according to the examples may have appropriate durability against ultraviolet rays and the like and appropriate biodegradability.

[0075] The first block may be represented by Chemical Formula 1 below.

[0076] [Chemical Formula]

[0077] Here, R1 is a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, R2 is a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, and m may be 1 to 20.

[0078] R1 may be a substituted or unsubstituted phenylene group, and R2 may be a butylene group.

[0079] The second block may be represented by Chemical Formula 2 below.

[0080] [Chemical Formula]

[0081] Here, R3 and R4 are each independently a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, and n may be 1 to 20.

[0082] R3 and R4 may be butylene groups.

[0083] The biodegradable polyester resin may have a structure in which the first block and the second block are alternately bonded to each other. The biodegradable polyester resin may be represented by Chemical Formula 3 below.

[0084] [Chemical Formula]

[0085] Here, R1 is a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, R2 is a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, and m may be 1 to 20. Also, R3 and R4 are each independently a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, and n may be 1 to 20.

[0086] The diol residue may include a residue of 1,4-butanediol or its derivative, the aromatic dicarboxylic acid residue may include a residue of terephthalic acid or its derivative, and the aliphatic dicarboxylic acid residue may include a residue of adipic acid or its derivative.

[0087] For example, the biodegradable polyester resin may include a first block containing residues of 1,4-butanediol or its derivatives and residues of terephthalic acid or its derivatives.

[0088] Alternatively, the biodegradable polyester resin may include a first block containing residues of 1,4-butanediol or its derivatives and residues of dimethyl terephthalate or its derivatives.

[0089] The biodegradable polyester resin may include a second block containing residues of 1,4-butanediol or its derivatives and residues of adipic acid or its derivatives.

[0090] Alternatively, the biodegradable polyester resin may include a second block containing residues of 1,4-butanediol or its derivatives and residues of succinic acid or its derivatives.

[0091] The biodegradable polyester resin according to an embodiment of the present invention may include a first block containing residues of 1,4-butanediol or its derivatives and residues of terephthalic acid or its derivatives, and a second block containing residues of 1,4-butanediol or its derivatives and residues of adipic acid or its derivatives.

[0092] The first block may be represented by Chemical Formula 4 below, and the second block may be represented by Chemical Formula 5 below.

[0093]

Chemical Formula

[0094] Here, m may be 1 to 20.

[0095]

Chemical Formula

[0096] Here, n may be from 1 to 20.

[0097] The biodegradable polyester resin may be represented by the following Chemical Formula 6.

[0098] [Chemical Formula]

[0099] Here, m is from 1 to 20, and n may be from 1 to 20.

[0100] When the first block and the second block satisfy the above configuration, it can be more advantageous for providing a biodegradable polyester sheet, film, or molded article that is excellent in biodegradability and hydrolysis resistance and has improved physical properties.

[0101] Further, when the biodegradable polyester resin contains the first block and the second block within the above range, the biodegradable polyester resin composition according to the examples may have appropriate mechanical properties and appropriate UV resistance properties.

[0102] Since the first block and the second block have the above characteristics, the mechanical properties of the biodegradable polyester resin composition according to the examples can be improved.

[0103] Since the first block and the second block have the above characteristics, the biodegradable polyester resin composition according to the examples may have appropriate UV resistance properties.

[0104] Since the first block and the second block have the above characteristics, the biodegradable polyester resin composition according to the examples may have an appropriate biodegradation rate.

[0105] Since the first block and the second block have the above characteristics, the biodegradable polyester resin composition according to the example may have an appropriate hydrolysis rate.

[0106] The biodegradable polyester resin may further contain a branching agent. The branching agent may contain at least one selected from the group consisting of a polyhydric alcohol having three or more valences, an anhydride, or a polycarboxylic acid having three or more valences. The branching agent can react with the diol, the aromatic dicarboxylic acid, and the aliphatic dicarboxylic acid. As a result, the branching agent may be included as part of the molecular structure in the biodegradable polyester resin.

[0107] At least one of the polyhydric alcohols having three or more valences may be selected from the group consisting of glycerol, pentaerythritol, or trimethylolpropane.

[0108] The above trivalent or higher carboxylic acid may be at least one selected from the group consisting of methane tricarboxylic acid, ethanetricarboxylic acid, citric acid, benzene-1,3,5-tricarboxylic acid, 5-sulfo-1,2,4-benzenetricarboxylic acid, ethane-1,1,2,2-tetracarboxylic acid, propane-1,1,2,3-tetracarboxylic acid, butane-1,2,3,4-tetracarboxylic acid, cyclopentane-1,2,3,4-tetracarboxylic acid, or benzene-1,2,4,5-tetracarboxylic acid.

[0109] The anhydride may contain at least one selected from the group consisting of trimellitic anhydride, succinic anhydride, methyl succinic anhydride, ethyl succinic anhydride, 2,3-butanedicarboxylic anhydride, 2,4-pentanedicarboxylic anhydride, 3,5-heptanedicarboxylic anhydride, 1,2,3,4-butanetetracarboxylic dianhydride, maleic anhydride, dodecyl succinic anhydride, or pyromellitic anhydride.

[0110] The branching agent may be contained in the biodegradable polyester resin at a content of about 0.1 wt% to about 5 wt% based on the entire biodegradable polyester resin. The branching agent may be contained in the biodegradable polyester resin at a content of about 0.1 wt% to about 3 wt% based on the entire biodegradable polyester resin. The branching agent may be contained in the biodegradable polyester resin at a content of about 0.1 wt% to about 1 wt% based on the entire biodegradable polyester resin.

[0111] Since the biodegradable polyester resin contains the branching agent within the above range, the biodegradable polyester resin composition according to the examples may have appropriate mechanical properties and appropriate biodegradability.

[0112] The biodegradable polyester resin may further contain a polycarbonate diol. The polycarbonate diol may be contained by being bonded in the molecular structure to the biodegradable polyester resin.

[0113] The polycarbonate diol can be produced by a dehydration condensation reaction of a carbonate and a polyhydric alcohol. At least one of the carbonates may be selected from the group consisting of dimethyl carbonate, diethyl carbonate, dibutyl carbonate, diphenyl carbonate, or ethylene carbonate. At least one of the polyhydric alcohols may be selected from the group consisting of ethylene glycol, diethylene glycol, neopentyl glycol, 1,6 - hexanediol, or 1,2 - propanediol.

[0114] The weight - average molecular weight of the polycarbonate diol may be about 500 g / mol to about 5000 g / mol. The weight - average molecular weight of the polycarbonate diol may be about 700 g / mol to about 4000 g / mol. The weight - average molecular weight of the polycarbonate diol may be about 800 g / mol to about 3500 g / mol.

[0115] Also, the viscosity of the polycarbonate diol may be about 300 cps to about 20,000 cps. The viscosity of the polycarbonate diol may be about 400 cps to about 15,000 cps. The viscosity of the polycarbonate diol may be about 500 cps to about 14,000 cps. The viscosity of the polycarbonate diol may be measured by ASTM / ISO 2555 at room temperature.

[0116] The OH value of the polycarbonate diol may be about 20 mgKOH / g to about 350 mgKOH / g. The OH value of the polycarbonate diol may be about 30 mgKOH / g to about 300 mgKOH / g.

[0117] The polycarbonate diol may be contained in the biodegradable polyester resin in an amount of about 0.1 part by weight to about 5 parts by weight based on 100 parts by weight of the biodegradable polyester resin. The polycarbonate diol may be contained in the biodegradable polyester resin in an amount of about 0.5 part by weight to about 3 parts by weight based on 100 parts by weight of the biodegradable polyester resin. The polycarbonate diol may be contained in the biodegradable polyester resin in an amount of about 1 part by weight to about 3 parts by weight based on 100 parts by weight of the biodegradable polyester resin.

[0118] Since the polycarbonate diol has the above characteristics, the biodegradable polyester resin composition according to the examples may have appropriate wet hardness, appropriate mechanical properties, appropriate solvent resistance, appropriate degree of hydrolysis, and appropriate degree of biodegradation.

[0119] The biodegradable polyester resin may further contain a polyether polyol. The polyether polyol may be contained by being bonded in the molecular structure to the biodegradable polyester resin.

[0120] The polyether polyol may be produced by adding propylene oxide (PO) or ethylene oxide (EO) to an initiator having two or more active hydrogens (-OH or NH2). Examples of the polyether polyol include polypropylene glycol, polyethylene glycol, or polytetramethylene glycol.

[0121] The weight average molecular weight of the polyether polyol may be from about 300 g / mol to about 5000 g / mol. The weight average molecular weight of the polyether polyol may be from about 400 g / mol to about 4000 g / mol. The weight average molecular weight of the polyether polyol may be from about 500 g / mol to about 3500 g / mol.

[0122] Also, the viscosity of the polyether polyol may be from about 300 cps to about 20000 cps. The viscosity of the polyether polyol may be from about 400 cps to about 15000 cps. The viscosity of the polyether polyol may be from about 500 cps to about 14000 cps. The viscosity of the polyether polyol may be measured at room temperature according to ASTM / ISO 2555.

[0123] The polyether polyol may be contained in the biodegradable polyester resin in an amount of about 0.1 part by weight to about 5 parts by weight based on 100 parts by weight of the biodegradable polyester resin. The polyether polyol may be contained in the biodegradable polyester resin in an amount of about 0.5 part by weight to about 3 parts by weight based on 100 parts by weight of the biodegradable polyester resin. The polyether polyol may be contained in the biodegradable polyester resin in an amount of about 1 part by weight to about 3 parts by weight based on 100 parts by weight of the biodegradable polyester resin.

[0124] Since the polyether polyol has the above characteristics, the biodegradable polyester resin composition according to the examples may have appropriate wet hardness, appropriate mechanical properties, appropriate solvent resistance, appropriate degree of hydrolysis, and appropriate degree of biodegradation.

[0125] The biodegradable polyester resin composition according to the examples may contain the biodegradable resin in a content of about 30 wt% or more based on the weight of the entire composition. The biodegradable polyester resin composition according to the examples may contain the biodegradable resin in a content of about 50 wt% or more based on the weight of the entire composition. The biodegradable polyester resin composition according to the examples may contain the biodegradable resin in a content of about 70 wt% or more based on the weight of the entire composition. The biodegradable polyester resin composition according to the examples may contain the biodegradable resin in a content of about 80 wt% or more based on the weight of the entire composition. The biodegradable polyester resin composition according to the examples may contain the biodegradable resin in a content of about 90 wt% or more based on the weight of the entire composition. The biodegradable polyester resin composition according to the examples may contain the biodegradable resin in a content of about 95 wt% or more based on the weight of the entire composition. The biodegradable polyester resin composition according to the examples may contain the biodegradable resin in a content of about 99 wt% or more based on the weight of the entire composition. The maximum content of the biodegradable resin in the biodegradable polyester resin composition according to the examples may be about 100 wt% based on the weight of the entire composition.

[0126] The biodegradable polyester resin composition according to the embodiment may further contain a reinforcing material. The reinforcing material can improve the mechanical properties of the biodegradable polyester resin composition according to the embodiment and the film or molded article produced thereby. Further, the reinforcing material can adjust the deformation characteristics of the biodegradable polyester resin composition according to the embodiment due to ultraviolet rays. Further, the reinforcing material can adjust the hydrolysis characteristics of the biodegradable polyester resin composition according to the embodiment. Further, the reinforcing material can adjust the biodegradability of the biodegradable polyester resin according to the embodiment.

[0127] The reinforcing material may be a fiber derived from biomass. The reinforcing material may be a fiber made of an organic substance. The reinforcing material may be nanocellulose.

[0128] The nanocellulose may be one or more selected from the group consisting of nanocrystalline cellulose, cellulose nanofiber, microfibrillated cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, cellulose acetate, methyl cellulose, ethyl cellulose, propyl cellulose, butyl cellulose, pentyl cellulose, hexyl cellulose, or cyclohexyl cellulose.

[0129] The nanocellulose may contain a metal bonded ionically. The nanocrystalline cellulose may contain a sodium element. Further, the nanocrystalline cellulose may contain a sulphate. The nanocrystalline cellulose may contain a carboxylate. The nanocrystalline cellulose may be cellulose hydrogen sulphate sodium salt.

[0130] The nanocellulose may be represented by the following Chemical Formula 7.

[0131] [Chemical]

[0132] Here, x is from 1 to 35, and y may be from 1 to 10. x may be from 15 to 35, and y may be from 1 to 10.

[0133] The nanocellulose may have a specific surface area of about 200 m 2 / g to about 600 m 2 / g. The nanocellulose may have a specific surface area of about 250 m 2 / g to about 500 m 2 / g.

[0134] The weight average molecular weight of the nanocellulose may be from about 10,000 g / mol to about 40,000 g / mol. The weight average molecular weight of the nanocrystalline cellulose may be from about 11,000 g / mol to about 35,000 g / mol.

[0135] The moisture content of the nanocrystalline cellulose may be from about 2 wt% to about 8 wt%. The moisture content of the nanocrystalline cellulose may be from about 4 wt% to about 6 wt%.

[0136] The average diameter of the nanocellulose may be from about 0.5 nm to about 10 nm. The average diameter of the nanocellulose may be from about 1 nm to about 8 nm. The average diameter of the nanocellulose may be from about 1.5 nm to about 7 nm.

[0137] The average length of the nanocellulose may be from about 20 nm to about 300 nm. The average length of the nanocellulose may be from about 30 nm to about 180 nm. The average length of the nanocellulose may be from about 35 nm to about 150 nm.

[0138] By having the diameter and length of the nanocellulose satisfy the above ranges, the biodegradability and physical properties of the biodegradable polyester resin, or the biodegradable polyester sheet, film, and molded article obtained using the same, can be further improved.

[0139] The diameter and length of the nanocellulose can be measured by atomic force microscopy in a state of being dispersed in water.

[0140] The sulfur content of the nanocellulose may be about 0.1 wt% to about 1.2 wt% based on the entire nanocrystalline cellulose. The sulfur content of the nanocellulose may be about 0.1 wt% to about 1.1 wt% based on the entire nanocellulose.

[0141] The pH of the nanocellulose may be 5 to 8. The pH of the nanocellulose may be 6 to 7.

[0142] The zeta potential of the nanocellulose may be about -25 mV to about -50 mV. The zeta potential of the nanocellulose may be about -30 mV to about -45 mV.

[0143] The nanocellulose may be included in the biodegradable polyester resin composition according to the examples in a content of about 0.01 parts by weight to about 2 parts by weight based on 100 parts by weight of the biodegradable polyester resin. The nanocellulose may be included in the biodegradable polyester resin composition according to the examples in a content of about 0.03 parts by weight to about 1.5 parts by weight based on 100 parts by weight of the biodegradable polyester resin. The nanocellulose may be included in the biodegradable polyester resin composition according to the examples in a content of about 0.04 parts by weight to about 1.2 parts by weight based on 100 parts by weight of the biodegradable polyester resin. The nanocellulose may be included in the biodegradable polyester resin composition according to the examples in a content of about 0.05 parts by weight to about 1 part by weight based on 100 parts by weight of the biodegradable polyester resin.

[0144] Since the nanocellulose has the above characteristics, it can be uniformly dispersed in the biodegradable polyester resin composition according to the examples.

[0145] Since the nanocellulose has the above characteristics, it can improve the mechanical properties of the biodegradable polyester resin composition according to the examples. Further, the nanocellulose can act as a crystallization nucleating agent and improve the crystallization rate of the biodegradable polyester resin composition according to the examples. Thereby, the nanocellulose can increase the crystallization temperature of the biodegradable polyester resin composition according to the examples.

[0146] Since the nanocellulose has the above characteristics, the biodegradable polyester resin composition according to the examples may have appropriate UV resistance characteristics.

[0147] Since the nanocellulose has the above characteristics, the biodegradable polyester resin composition according to the examples may have an appropriate biodegradation rate.

[0148] Since the nanocellulose has the above characteristics, the biodegradable polyester resin composition according to the examples may have an appropriate hydrolysis rate.

[0149] The biodegradable polyester resin composition according to the examples may contain a metal salt.

[0150] The metal salt may be contained in an amount of about 0.1 ppm to about 1000 ppm based on the total weight of the biodegradable polyester resin composition according to the examples. The metal salt may be contained in an amount of about 1 ppm to about 500 ppm based on the total weight of the biodegradable polyester resin composition according to the examples. The metal salt may be contained in an amount of about 1 ppm to about 100 ppm based on the total weight of the biodegradable polyester resin composition according to the examples. The metal salt may be contained in an amount of about 1 ppm to about 50 ppm based on the total weight of the biodegradable polyester resin composition according to the examples.

[0151] At least one of the metal salts may be selected from the group consisting of nitrates, sulfates, hydrochlorides, carboxylates, etc. At least one of the metal salts may be selected from the group consisting of titanium salts, silicon salts, sodium salts, calcium salts, potassium salts, magnesium salts, copper salts, iron salts, aluminum salts, silver salts, etc. At least one of the metal salts may be selected from the group consisting of magnesium acetate, calcium acetate, potassium acetate, copper nitrate, silver nitrate, sodium nitrate, etc.

[0152] The metal salt may contain one or more selected from the group consisting of iron (Fe), magnesium (Mg), nickel (Ni), cobalt (Co), copper (Cu), palladium (Pd), zinc (Zn), vanadium (V), titanium (Ti), indium (In), manganese (Mn), silicon (Si), and tin (Sn).

[0153] Further, the metal salt may be selected from the group consisting of acetate, nitrate, nitride, sulfide, sulfate, sulfoxide, hydroxide, hydrate, chloride, chlorinate, and bromide.

[0154] Since the biodegradable polyester resin composition according to the examples contains the metal salt in the above content, the hydrolysis rate and the biodegradation rate can be appropriately adjusted.

[0155] Since the biodegradable polyester resin composition according to the examples contains the metal salt in the above content, the hydrolysis rate and the biodegradation rate can be appropriately adjusted.

[0156] The biodegradable polyester resin composition according to the examples may further contain a hydrolysis-resistant agent.

[0157] The hydrolysis-resistant agent may be selected from at least one or more silicon-based compounds such as silane, silazane, or siloxane.

[0158] The hydrolysis-resistant agent may contain an alkoxysilane. The hydrolysis-resistant agent may contain trimethoxysilane and / or triethoxysilane. The hydrolysis-resistant agent may contain an alkoxysilane containing an epoxy group. The hydrolysis-resistant agent may contain at least one or more selected from the group consisting of 3-glycidyloxypropyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, or 3-glycidoxypropyltriethoxysilane.

[0159] The hydrolysis-resistant agent may be contained in the biodegradable polyester resin composition according to the examples in an amount of about 1 ppm to about 10,000 ppm. The hydrolysis-resistant agent may be contained in the biodegradable polyester resin composition according to the examples in an amount of about 1 ppm to about 1,000 ppm. The hydrolysis-resistant agent may be contained in the biodegradable polyester resin composition according to the examples in an amount of about 5 ppm to 500 ppm. The hydrolysis-resistant agent may be contained in the biodegradable polyester resin composition according to the examples in an amount of about 10 ppm to 300 ppm.

[0160] The hydrolysis-resistant agent may be one that binds to the biodegradable polyester resin. The hydrolysis-resistant agent may be one that chemically binds to the biodegradable polyester resin. The hydrolysis-resistant agent may be one that chemically binds to a polymer contained in the biodegradable polyester resin. The hydrolysis-resistant agent can couple polymers contained in the biodegradable polyester resin to each other.

[0161] The biodegradable polyester resin composition according to the examples may have appropriate hydrolysis resistance characteristics because it contains the hydrolysis-resistant agent within the above range. In particular, the biodegradable polyester resin according to the examples may have appropriate initial hydrolysis characteristics and improved biodegradability because it contains the hydrolysis-resistant agent within the above range.

[0162] As a result, the biodegradable polyester resin composition according to the examples may contain a silicon element. The biodegradable polyester resin composition according to the examples may contain a silicon element at a content of about 0.1 ppm to about 100 ppm. The biodegradable polyester resin composition according to the examples may contain a silicon element at a content of about 0.1 ppm to about 50 ppm. The biodegradable polyester resin composition according to the examples may contain a silicon element at a content of about 0.1 ppm to about 20 ppm.

[0163] Also, the hydrolysis-resistant agent can also react with terminal carboxyl groups or unreacted carboxyl groups. As a result, the biodegradable polyester resin composition according to the examples may have a low acid value.

[0164] Also, the hydrolysis-resistant agent couples the polymers contained in the biodegradable polyester resin, and the biodegradable polyester resin composition according to the examples can increase the proportion of high-molecular-weight polymers. As a result, the mechanical properties of the biodegradable polyester resin composition according to the examples can be improved.

[0165] The biodegradable polyester resin composition according to the embodiment may further contain a chain extender.

[0166] The chain extender may contain isocyanate.

[0167] The chain extender may be at least one selected from the group consisting of monofunctional isocyanate or polyfunctional isocyanate.

[0168] The chain extender may be at least one selected from the group consisting of tolylene 2,4-diisocyanate, tolylene 2,6-diisocyanate, diphenylmethane 4,4'-diisocyanate, and 2,4'-diisocyanate, naphthalene 1,5-diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, isophorone diisocyanate, and methylene bis(4-isocyanatocyclohexane).

[0169] The chain extender may contain triisocyanate. The chain extender may contain tris(4-isocyanatophenyl)methane.

[0170] The chain extender may contain an acrylic polymer. The acrylic polymer may contain an acrylic group. The acrylic group may be bonded as a side chain to the main chain. The acrylic polymer may contain an epoxy group. The epoxy group may be bonded as a side chain to the main chain.

[0171] The chain extender may contain a styrene copolymer. The chain extender may contain styrene glycidyl acrylate.

[0172] The chain extender may be chemically bonded to the biodegradable polyester resin. The chain extender may be chemically bonded to a polymer contained in the biodegradable polyester resin. The chain extender may be bonded to the end of a polymer contained in the biodegradable polyester resin. Further, the chain extender may be bonded to the ends of three polymers contained in the biodegradable polyester resin.

[0173] The chain extender may be contained in the biodegradable polyester resin composition according to the examples in a content of about 0.1 wt% to about 10 wt% based on the total composition. The chain extender may be contained in the biodegradable polyester resin composition according to the examples in a content of about 0.2 wt% to about 8 wt% based on the total composition. The chain extender may be contained in the biodegradable polyester resin composition according to the examples in a content of about 2 wt% to about 0.3 wt% based on the total composition.

[0174] When the biodegradable polyester resin composition according to the examples contains the chain extender within the above range, it may have appropriate hydrolysis resistance and appropriate biodegradability.

[0175] Further, the chain extender can also react with the terminal carboxyl group or unreacted carboxyl group. As a result, the biodegradable polyester resin composition according to the examples may have a low acid value.

[0176] Further, the chain extender can couple the polymers contained in the biodegradable polyester resin, and the biodegradable polyester resin composition according to the examples can increase the proportion of high-molecular-weight polymers. As a result, the mechanical properties of the biodegradable polyester resin composition according to the examples can be improved.

[0177] The biodegradable polyester resin composition according to the examples may contain oligomers. The molecular weight of the oligomers may be about 400 to about 1300.

[0178] The oligomer may be included in the biodegradable polyester resin composition according to the examples at about 3000 ppm to about 30000 ppm based on the total resin composition. The oligomer may be included in the biodegradable polyester resin composition according to the examples at about 5000 ppm to about 20000 ppm based on the total resin composition. The oligomer may be included in the biodegradable polyester resin composition according to the examples at about 5000 ppm to about 15000 ppm based on the total resin composition. The oligomer may be included in the biodegradable polyester resin composition according to the examples at about 7000 ppm to about 15000 ppm based on the total resin composition.

[0179] The oligomer may be a reaction product of at least two or more of the diol, the aromatic dicarboxylic acid, and the aliphatic dicarboxylic acid. The oligomer may be a reaction product of 1,4-butanediol, terephthalic acid, and adipic acid.

[0180] The oligomer may include an oligomer in which the molar ratio of the aliphatic dicarboxylic acid is higher than the molar ratio of the aromatic dicarboxylic acid. Among the oligomers, the ratio of the oligomer containing relatively more of the aliphatic dicarboxylic acid may be even higher than the ratio of the oligomer containing relatively more of the aromatic dicarboxylic acid.

[0181] The oligomer can appropriately adjust the degree of hydrolysis of the biodegradable polyester resin composition according to the examples. The oligomer may be a hydrolysis regulator that appropriately adjusts the degree of hydrolysis of the biodegradable polyester resin composition according to the examples.

[0182] Also, the oligomer can appropriately adjust the biodegradability of the biodegradable polyester resin composition according to the examples. The oligomer may be a biodegradability regulator that appropriately adjusts the biodegradability of the biodegradable polyester resin composition according to the examples.

[0183] The biodegradable polyester resin composition according to the embodiment may contain a heat stabilizer. The heat stabilizer may be a phosphorus-based heat stabilizer.

[0184] The heat stabilizer may be at least one selected from the group consisting of amine-based high-temperature heat stabilizers such as tetraethylenepentamine, triethyl phosphonoacetate, phosphoric acid, phosphorous acid, polyphosphric acid, trimethyl phosphate (TMP), triethyl phosphate, trimethyl phosphine, or triphenyl phosphine.

[0185] Also, the heat stabilizer may be an antioxidant having an antioxidant function.

[0186] The content of the heat stabilizer may be about 3000 ppm or less based on the total weight of the biodegradable polyester resin. The content of the heat stabilizer may be, for example, 10 ppm to 3,000 ppm, 20 ppm to 2,000 ppm, 20 ppm to 1,500 ppm, or 20 ppm to 1,000 ppm based on the total weight of the biodegradable polyester resin. By the content of the heat stabilizer satisfying the above range, the deterioration of the polymer due to high temperature during the reaction process can be controlled, the end groups of the polymer can be reduced, and the color can be improved. Further, the heat stabilizer can suppress the activation of a titanium-based catalyst or the like and adjust the reaction rate.

[0187] The biodegradable polyester resin composition according to the example may contain an elongation improver. Examples of the elongation improver include oils such as paraffin oil, naphthenic oil, or aromatic oil, or adipates such as dibutyl adipate, diethylhexyl adipate, dioctyl adipate, or diisopropyl adipate.

[0188] The elongation improver may be contained in the biodegradable polyester resin composition according to the example in an amount of about 0.001 part by weight to about 1 part by weight based on 100 parts by weight of the biodegradable polyester resin. The elongation improver may be contained in the biodegradable polyester resin composition according to the example in an amount of about 0.01 part by weight to about 1 part by weight based on 100 parts by weight of the biodegradable polyester resin.

[0189] The biodegradable polyester resin composition according to the example may contain an inorganic filler. The inorganic filler may be at least one selected from the group consisting of calcium sulfate, barium sulfate, talc, talcum powder, bentonite, kaolin, chalk powder, calcium carbonate, graphite, gypsum, electrically conductive carbon black, calcium chloride, iron oxide, aluminum oxide, potassium oxide, dolomite, silicon dioxide, wollastonite, titanium dioxide, silicate, mica, glass fiber, or mineral fiber.

[0190] Regarding the inorganic filler, the particle size (D 50 ) at which the cumulative volume is 50% based on the volume in the particle size distribution obtained by the laser diffraction method may be about 100 μm or less, about 85 μm or less, about 70 μm or less, about 50 μm or less, about 25 μm or less, about 10 μm or less, about 5 μm or less, about 3 μm or less, or about 1 μm or less.

[0191] Also, the specific surface area of the inorganic filler may be about 100 m 2 / g or more. For example, the specific surface area of the inorganic filler may be about 100 m 2 / g or more, about 105 m 2 / g or more, or about 110 m2 It may also be / g or more.

[0192] The inorganic filler may be included in the biodegradable polyester resin composition according to the examples at a content of about 3 parts by weight to about 50 parts by weight based on 100 parts by weight of the biodegradable polyester resin. The inorganic filler may be included in the biodegradable polyester resin composition according to the examples at a content of about 5 parts by weight to about 30 parts by weight based on 100 parts by weight of the biodegradable polyester resin.

[0193] The inorganic filler may be included at a content of about 3,000 ppm or less based on the total weight of the biodegradable polyester resin composition according to the examples. For example, the content of the inorganic filler may be about 3,000 ppm or less, about 1,500 ppm or less, about 1,200 ppm or less, about 800 ppm or less, or about 600 ppm or less based on the total weight of the biodegradable polyester resin composition according to the examples, and may also be about 50 ppm or more, about 100 ppm or more, about 130 ppm or more, about 150 ppm or more, or about 180 ppm or more.

[0194] Since the biodegradable polyester resin composition according to the examples contains the inorganic filler at the above content, it may have mechanical properties, appropriate UV resistance, an appropriate biodegradation rate, and an appropriate hydrolysis rate of the biodegradable polyester resin composition according to the examples.

[0195] The biodegradable polyester resin composition according to the examples may further contain two types of biodegradable polyester resins. The biodegradable polyester resin composition according to the examples may be a composite resin composition containing two or more types of resins, fillers, and additives.

[0196] The two biodegradable polyester resins may be at least one selected from the group consisting of polybutylene azelate terephthalate (PBAzT), polybutylene sebacate terephthalate (PBSeT), polybutylene succinate terephthalate (PBST), polyhydroxyalkanoate (PHA), or polylactic acid (PLA).

[0197] The two biodegradable polyester resins may be contained in the biodegradable polyester resin composition according to the examples at a content of about 10 parts by weight to about 100 parts by weight based on 100 parts by weight of the biodegradable polyester resin. The two biodegradable polyester resins may be contained in the biodegradable polyester resin composition according to the examples at a content of about 10 parts by weight to about 60 parts by weight based on 100 parts by weight of the biodegradable polyester resin. The two biodegradable polyester resins may be contained in the biodegradable polyester resin composition according to the examples at a content of about 20 parts by weight to about 50 parts by weight based on 100 parts by weight of the biodegradable polyester resin.

[0198] The two biodegradable polyester resins can complement the mechanical, optical, and chemical properties of the biodegradable polyester resin. Since the biodegradable polyester resin composition according to the examples contains the two biodegradable polyester resins at the above content, it may have mechanical properties, appropriate UV resistance, an appropriate biodegradation rate, and an appropriate hydrolysis rate of the biodegradable polyester resin composition according to the examples.

[0199] Also, the number of terminal carboxyl groups in the biodegradable polyester resin composition according to the examples may be about 50 eq / ton or less. For example, the number of terminal carboxyl groups in the biodegradable polyester resin according to the examples may be about 50 eq / ton or less, about 48 eq / ton or less, about 45 eq / ton or less, or about 42 eq / ton or less. When the number of terminal carboxyl groups is adjusted within the above range and the biodegradable polyester resin composition according to the examples is extruded to form a molded product, deterioration can be prevented and improved mechanical properties can be realized.

[0200] Also, the intrinsic viscosity (IV) of the biodegradable polyester resin composition according to the examples may be about 0.9 dl / g or more. The intrinsic viscosity of the biodegradable polyester resin composition according to the examples may be about 0.95 dl / g or more, about 1.0 dl / g or more, about 1.1 dl / g or more, about 1.2 dl / g or more, or about 1.3 dl / g or more. The intrinsic viscosity of the biodegradable polyester resin composition according to the examples may be about 0.95 dl / g to about 1.7 dl / g. The intrinsic viscosity of the biodegradable polyester resin composition according to the examples may be about 1.3 dl / g to about 1.7 dl / g. The intrinsic viscosity of the biodegradable polyester resin composition according to the examples may be about 1.4 dl / g to about 1.7 dl / g.

[0201] The process of manufacturing the biodegradable polyester resin composition according to the examples is as follows.

[0202] Referring to FIG. 1, the manufacturing apparatus for the biodegradable polyester resin includes a slurry stirrer 100, an esterification reaction section 200, a polycondensation reaction section 300, a post-treatment section 400, a first recovery section 510, and a second recovery section 520.

[0203] The method for manufacturing the biodegradable polyester resin includes a step of manufacturing a slurry containing the diol and the aromatic dicarboxylic acid.

[0204] The step of manufacturing the slurry includes the step of mixing and processing the diol and the aromatic dicarboxylic acid. That is, the step of manufacturing the slurry is a pretreatment step before the esterification reaction, and may be a step of mixing the diol and the aromatic dicarboxylic acid to form a slurry. At this time, the diol may contain a biomass-based diol component.

[0205] The temperature of the slurry of the diol and the aromatic dicarboxylic acid may be about 5°C to about 15°C higher than the melting point of the diol. For example, when the diol is 1,4-butanediol, the temperature of the slurry may be about 35°C to about 45°C.

[0206] The diol and the aromatic dicarboxylic acid can be put into the slurry stirrer 100 and stirred to produce the slurry.

[0207] By mixing and pretreating the diol and the aromatic dicarboxylic acid to form a slurry, not only can the diol and the aromatic dicarboxylic acid react uniformly, but it is also effective in promptly carrying out the esterification reaction rate, so the reaction efficiency can be enhanced.

[0208] In particular, when the aromatic dicarboxylic acid has complete crystallinity and is in powder form, such as terephthalic acid, its solubility in the diol is very low, and a homogeneous reaction may not easily occur. Therefore, the pretreatment process of forming the slurry can provide biodegradable polyester resins, sheets, films, and molded products with excellent physical properties according to embodiments of the present invention, and can play a very important role in enhancing the reaction efficiency.

[0209] When the aromatic dicarboxylic acid is terephthalic acid, the terephthalic acid has complete crystallinity, has no melting point, and is a white crystal that sublimes at nearly 300 °C under normal pressure. Its solubility in the diol is very low, and a homogeneous reaction is difficult to occur. Therefore, when a pretreatment process is carried out before the esterification reaction, it can react with the diol within the solid matrix of terephthalic acid to increase the surface area and induce a uniform reaction.

[0210] Also, when the aromatic dicarboxylic acid is dimethyl terephthalate, the pretreatment process can melt the dimethyl terephthalate at about 142 °C to 170 °C and react it with the diol, so that the esterification reaction rate can be made faster and more efficient.

[0211] On the other hand, in the pretreatment stage of manufacturing the slurry, the structure and physical properties of the biodegradable polyester resin may vary depending on the particle size, particle size distribution, pretreatment reaction conditions, etc. of the aromatic dicarboxylic acid.

[0212] For example, the aromatic dicarboxylic acid contains terephthalic acid, and the average particle size (D50) of the terephthalic acid measured by a particle size analyzer Microtrac S3500 in the particle size distribution (PSD) may be 10 μm to 400 μm, and the standard deviation with respect to the average particle size (D50) may be 100 or less. The standard deviation means the square root of the dispersion. The average particle size (D50) of the terephthalic acid may be, for example, 20 μm to 200 μm, for example, 30 μm to 180 μm, or for example, 100 μm to 160 μm. When the average particle size (D50) of the terephthalic acid satisfies the above range, it may be more advantageous in terms of improving the solubility in the diol and the reaction rate.

[0213] In the pretreatment process, the diol and the aromatic dicarboxylic acid can be mixed and put into the slurry stirrer 100 (tank).

[0214] The slurry stirrer 100, for example, with an anchor - type bottom, a height from the bottom to the agitator of 20 mm or more, and equipped with three or more rotating blades, may be more advantageous for achieving an efficient stirring effect.

[0215] For example, the height from the bottom to the agitator of the slurry stirrer 100 may be 20 mm or more, that is, there may be almost no gap between the reactor and the bottom of the agitator. In this case, a slurry can be obtained without precipitation. If the pattern, form, and rotating blades of the agitator do not meet the above conditions, when the diol and the aromatic dicarboxylic acid are initially mixed, the aromatic dicarboxylic acid may settle to the bottom, and in this case, phase separation may occur.

[0216] The pretreatment step for manufacturing the slurry may include a step of mixing the diol and the aromatic dicarboxylic acid and stirring at about 30°C to about 100°C, at about 50 rpm to about 200 rpm for 10 minutes or more, for example, for 10 minutes to 200 minutes.

[0217] The diol may have the same characteristics as described above.

[0218] The diol can be charged all at once or dividedly. For example, the diol can be divided and charged when mixing with the aromatic dicarboxylic acid and when mixing with the aliphatic dicarboxylic acid.

[0219] The aromatic dicarboxylic acid may have the same characteristics as described above.

[0220] In the pretreatment stage of manufacturing the slurry, the molar ratio of the diol to the aromatic dicarboxylic acid may be about 0.8:1 to about 2:1. In the pretreatment stage of manufacturing the slurry, the molar ratio of the diol to the aromatic dicarboxylic acid may be about 1.1:1 to about 1.5:1. In the pretreatment stage of manufacturing the slurry, the molar ratio of the diol to the aromatic dicarboxylic acid may be about 1.2:1 to about 1.5:1. In the pretreatment stage of manufacturing the slurry, the molar ratio of the diol to the aromatic dicarboxylic acid may be about 1.2:1 to about 1.8:1.

[0221] When the diol is added in a larger amount than the aromatic dicarboxylic acid, the aromatic dicarboxylic acid can be easily dispersed.

[0222] Also, an additive can be added to the slurry. The nanocellulose and / or the metal salt may be added to the slurry in the form of a dispersion or a solution.

[0223] The method for manufacturing the biodegradable polyester resin uses a slurry obtained by mixing and pretreating a diol and an aromatic dicarboxylic acid to carry out an esterification reaction to obtain a prepolymer, and by subjecting the prepolymer to a polycondensation reaction, the structure and physical properties of the biodegradable polyester resin targeted by the embodiments of the present invention can be efficiently achieved.

[0224] The method for manufacturing the biodegradable polyester resin includes a step of subjecting the slurry and the aliphatic dicarboxylic acid to an esterification reaction to produce a prepolymer. The slurry and the aliphatic dicarboxylic acid can react in the ester reaction section.

[0225] In the esterification reaction, the reaction time can be shortened by using the slurry. For example, the slurry obtained in the pretreatment stage can shorten the reaction time of the ester reaction by 1.5 times or more.

[0226] The esterification reaction can be carried out at least two or more times. A prepolymer to be introduced into the polycondensation step can be formed by the esterification reaction.

[0227] In one embodiment, the esterification reaction can be carried out once after an aliphatic dicarboxylic acid, or a diol and an aliphatic dicarboxylic acid are added to the slurry. That is, the slurry is introduced into the esterification reactor, and the aliphatic dicarboxylic acid alone, or the aliphatic dicarboxylic acid and the diol are introduced into the esterification reactor to carry out the esterification reaction. At this time, the molar ratio of the diol to the aliphatic dicarboxylic acid added to the slurry may be about 1:1 to about 1.8:1.

[0228] The diol and the aliphatic dicarboxylic acid may be in a slurry state and may be added to the slurry containing the aromatic dicarboxylic acid.

[0229] The average particle size (D50) of the aliphatic dicarboxylic acid in the slurry of the diol and the aliphatic dicarboxylic acid may be about 50 μm to about 150 μm. The average particle size (D50) of the aliphatic dicarboxylic acid in the slurry of the diol and the aliphatic dicarboxylic acid may be about 60 μm to about 120 μm.

[0230] In the esterification reaction, the molar number of the total diol introduced may be about 1.0 to about 1.8 with respect to the total molar number of the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid. In the esterification reaction, the molar number of the total diol introduced may be about 1.1 to about 1.6 with respect to the total molar number of the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid.

[0231] Also, the temperature of the slurry of the diol and the aliphatic dicarboxylic acid may be about 5 °C to about 15 °C higher than the melting point of the diol.

[0232] In addition, various additives such as the nanocellulose may also be added to the slurry of the diol and the aliphatic dicarboxylic acid.

[0233] The esterification reaction can be carried out at about 250 °C or lower for about 0.5 hour to about 5 hours. Specifically, the esterification reaction can be carried out at about 180 °C to about 250 °C, about 185 °C to about 240 °C or about 200 °C to about 240 °C under normal pressure or reduced pressure until the by-product water theoretically reaches 95%. For example, the esterification reaction can be carried out for 0.5 hour to 5.5 hours, 0.5 hour to 4.5 hours or 1 hour to 4 hours, but is not limited thereto.

[0234] In one embodiment, the polycarbonate diol and / or the polyether polyol can be mixed with the slurry to carry out a first esterification reaction. Differently, the polycarbonate diol and / or the polyether polyol can be introduced into a second esterification reaction.

[0235] In addition, after the first ester reaction, a mixture of the aliphatic dicarboxylic acid and the diol can be introduced into the esterification reaction section to carry out a second ester reaction together with the first ester reaction product. Also, the polycarbonate diol and / or the polyether polyol can be introduced into the second esterification reaction.

[0236] The first ester reaction can be carried out at 250 °C or lower for 1.25 hours to 4 hours. Specifically, the first esterification reaction can be carried out at 180 °C to 250 °C, 185 °C to 240 °C or 200 °C to 240 °C under normal pressure or reduced pressure until the by-product water theoretically reaches 95%. For example, the first esterification reaction can be carried out for 1.25 hours to 4 hours, 1.25 hours to 3.5 hours, or 2.5 hours to 3 hours, but is not limited thereto.

[0237] The second ester reaction can be carried out at about 250 °C or lower for 0.25 hours to 3.5 hours. Specifically, the second esterification reaction can be carried out at 180 °C to 250 °C, 185 °C to 240 °C or 200 °C to 240 °C under normal pressure or reduced pressure until the by-product water theoretically reaches 95%. For example, the second esterification reaction can be carried out for 0.5 hours to 3 hours, 1 hour to 2.5 hours or 1.5 hours to 2.5 hours, but is not limited thereto.

[0238] In the first ester reaction and the second ester reaction, the reaction temperature, reaction time, and the contents of the diol, aromatic dicarboxylic acid, and aliphatic dicarboxylic acid introduced are respectively adjusted to adjust the ratio of the number of the first block and the second block, etc. Further, when the ester reaction is carried out separately into the first ester reaction and the second ester reaction, the overall ester reaction can be precisely controlled. Thereby, when the ester reaction is carried out separately, the reaction stability and reaction uniformity of the ester reaction can be improved.

[0239] Further, in the second ester reaction, the branching agent may be further introduced. That is, the aliphatic dicarboxylic acid, the mixture of the diol, the branching agent, and the product of the first ester reaction can react to form the prepolymer. The characteristics and content of the branching agent may be the same as those described above.

[0240] The prepolymer can be formed by the esterification reaction.

[0241] The number average molecular weight of the prepolymer may be from about 500 to about 10,000 g / mol. For example, the number average molecular weight of the prepolymer may be from about 500 to about 8,500 g / mol, from about 500 to about 8,000 g / mol, from about 500 to about 7,000 g / mol, from about 500 g / mol to about 5,000 g / mol, or from about 800 g / mol to about 4,000 g / mol. By the number average molecular weight of the prepolymer satisfying the above range, the molecular weight of the polymer in the polycondensation reaction can be efficiently increased.

[0242] The number average molecular weight can be measured using gel permeation chromatography (GPC). Specifically, the data calculated by gel permeation chromatography has various items such as Mn, Mw, and Mp, and among these, the molecular weight can be measured based on the number average molecular weight (Mn).

[0243] The reinforcing material, the branching agent, the polycarbonate diol, the polyether polyol, or the metal salt may be introduced together with the slurry before the esterification reaction. The reinforcing material, the branching agent, the polycarbonate diol, the polyether polyol, and / or the metal salt may be introduced into the esterification reaction section 200 during the esterification reaction. The reinforcing material, the branching agent, the polycarbonate diol, the polyether polyol, and / or the metal salt may be introduced into the ester reaction product after the esterification reaction. Also, the reinforcing material, the branching agent, the polycarbonate diol, the polyether polyol, and / or the metal salt may be introduced together with the aliphatic dicarboxylic acid. Further, the reinforcing material, the branching agent, the polycarbonate diol, the polyether polyol, and / or the metal salt may be introduced into the esterification reaction section 200 after the first ester reaction and before the second ester reaction.

[0244] Since the reinforcing material and / or the metal salt are introduced into the esterification reaction, the reinforcing material and / or the metal salt can be uniformly dispersed in the biodegradable polyester resin.

[0245] The reinforcing material may have the same characteristics as described above. In particular, the nanocellulose can be used as the reinforcing material.

[0246] The nanocellulose may be pretreated by a bead mill, by ultrasonic waves, or by high-speed dispersion at about 1000 rpm to about 1500 rpm before being introduced. Specifically, the nanocellulose may be pretreated by a bead mill or by ultrasonic waves in a water-dispersed state.

[0247] For now, the bead mill pretreatment can be performed using a vertical mill or a horizontal mill as a wet milling device. Although a horizontal mill is preferable in that it can hold a larger amount of beads inside the chamber, reduces mechanical eccentric wear, reduces bead wear, and is easy to maintain, it is not limited to this.

[0248] The bead mill pretreatment can be performed using one or more types of beads selected from the group consisting of zirconium, zircon, zirconia, quartz, and aluminum oxide.

[0249] Specifically, the bead mill pretreatment can be performed using beads having a diameter of about 0.3 mm to about 1 mm. For example, the diameter of the beads may be about 0.3 mm to about 0.9 mm, about 0.4 mm to about 0.8 mm, about 0.45 mm to about 0.7 mm, or about 0.45 mm to about 0.6 mm.

[0250] By having the bead diameter within the above range, the dispersibility of the nanocellulose can be further improved. If the bead diameter exceeds the above range, the average particle size and particle size deviation of the nanocellulose may increase, resulting in lower dispersibility.

[0251] Also, for the bead mill pretreatment, it is preferable to use beads with a specific gravity higher than that of nanocellulose in terms of being able to transmit sufficient energy. For example, the beads may be one or more selected from the group consisting of zirconium, zircon, zirconia, quartz, and aluminum oxide, which have a higher specific gravity than the water-dispersed nanocellulose. Although zirconium beads with a specific gravity four times or more higher than that of the water-dispersed nanocellulose are preferable, it is not limited thereto.

[0252] Also, the ultrasonic pretreatment is a method of physically closing or pulverizing nanoparticles by waves generated by emitting ultrasonic waves of 20 kHz into a solution.

[0253] The ultrasonic pretreatment can be performed at an output of 30000 J / s or less for a time of less than 30 minutes. For example, the ultrasonic pretreatment can be performed at an output of 25000 J / s or less or 22000 J / s or less for a time of 25 minutes or less, 20 minutes or less, or 18 minutes or less. By satisfying the above ranges for the output and the implementation time, the effect of the ultrasonic pretreatment, that is, the improvement of dispersibility, can be maximized. If the output exceeds the above range, on the contrary, the nanoparticles may re-aggregate and the dispersibility may decrease.

[0254] The nanocellulose according to the embodiment may be subjected to bead mill pretreatment or ultrasonic pretreatment. Or, the nanocellulose according to the embodiment may be subjected to both bead mill pretreatment and ultrasonic pretreatment. At this time, it is preferable to perform the ultrasonic pretreatment after the bead mill pretreatment in terms of preventing re-aggregation and improving dispersibility.

[0255] The nanocellulose according to the embodiment may be subjected to bead mill pretreatment or ultrasonic pretreatment. Or, the nanocellulose according to the embodiment may be subjected to both bead mill pretreatment and ultrasonic pretreatment. At this time, it is preferable to perform the ultrasonic pretreatment after the bead mill pretreatment in terms of preventing re-aggregation and improving dispersibility.

[0256] Since the nanocellulose contains ionically bonded metal, its dispersibility in water is very high. Further, a highly dispersed aqueous dispersion of the nanocellulose can be obtained by the bead mill pretreatment and / or the ultrasonic pretreatment. The content of the nanocellulose in the aqueous dispersion of the nanocellulose may be about 1 wt% to about 50 wt%.

[0257] A titanium-based catalyst and / or a germanium-based catalyst can be used for the esterification reaction. Specifically, the titanium-based catalyst and / or the germanium-based catalyst can be added to the slurry to carry out the esterification reaction.

[0258] Further, before the first esterification reaction, the titanium-based catalyst and / or the germanium-based catalyst may be added to the slurry, and the titanium-based catalyst and / or the germanium-based catalyst may be further added to the product of the first esterification reaction.

[0259] The catalyst may be added to the first esterification product after the first esterification reaction and before the second esterification reaction.

[0260] The biodegradable polyester resin may contain one or more titanium-based catalysts selected from the group consisting of titanium isopropoxide, antimony trioxide, dibutyltin oxide, tetrapropyl titanate, tetrabutyl titanate, tetraisopropyl titanate, antimony acetate, calcium acetate, and magnesium acetate, or one or more germanium-based catalysts selected from the group consisting of germanium oxide, germanium methoxide, germanium ethoxide, tetramethylgermanium, tetraethylgermanium, and germanium sulfide.

[0261] Also, the content of the catalyst may be about 50 ppm to 1000 ppm based on the total weight of the diol, aromatic dicarboxylic acid, and aliphatic dicarboxylic acid. For example, it may contain a titanium-based catalyst or a germanium-based catalyst of about 60 ppm to about 1000 ppm, about 80 ppm to about 1000 ppm, about 100 ppm to about 1000 ppm, or about 80 ppm to about 800 ppm. By the catalyst content satisfying the above range, the physical properties can be further improved.

[0262] Also, the heat stabilizer may be introduced together with the slurry before the esterification reaction. The heat stabilizer may be introduced into the esterification reaction section 200 during the esterification reaction. The heat stabilizer may be introduced into the ester reaction product after the esterification reaction. Also, the heat stabilizer may be introduced together with the aliphatic dicarboxylic acid. Also, the heat stabilizer may be introduced into the esterification reaction section 200 after the first ester reaction and before the second ester reaction.

[0263] The characteristics of the heat stabilizer may be the same as those described above.

[0264] The content of the heat stabilizer may be 3,000 ppm or less based on the total weight of the diol, aromatic dicarboxylic acid, and aliphatic dicarboxylic acid. Specifically, the content of the heat stabilizer may be, for example, 10 ppm to 3,000 ppm, 20 ppm to 2,000 ppm, 20 ppm to 1,500 ppm, or 20 ppm to 1,000 ppm based on the total weight of the diol, aromatic dicarboxylic acid, and aliphatic dicarboxylic acid. By the heat stabilizer content satisfying the above range, the deterioration of the polymer due to high temperature during the reaction process can be controlled, the end groups of the polymer can be reduced, and the color can be improved.

[0265] After the esterification reaction is completed, one or more selected from the group consisting of additives such as silica, potassium, or magnesium, and color correctors such as cobalt acetate may be further added to the esterification reaction product. That is, after the esterification reaction is completed, the additive and / or color corrector can be added and stabilized, and then the polycondensation reaction can be carried out. The additive and / or the color corrector may be added after the esterification reaction is completed and introduced into the polycondensation reaction section 300 together with the prepolymer. Thereby, the additive and / or the color corrector can be uniformly dispersed in the biodegradable polyester resin.

[0266] Also, after the esterification reaction is completed, the inorganic filler may be added to the esterification reaction product. That is, after the esterification reaction is completed, the inorganic filler can be added and stabilized, and then the polycondensation reaction can be carried out. The characteristics of the inorganic filler are as described above. The inorganic filler can be introduced into the polycondensation reaction section 300 together with the prepolymer to carry out the polycondensation step. Thereby, the inorganic filler can be uniformly dispersed in the biodegradable polyester resin.

[0267] Also, the first recovery section 510 recovers reaction by-products such as water from the esterification reaction section 200. The first recovery section 510 can apply a vacuum pressure to the esterification reaction section 200 or perform reflux to recover the by-products generated in the esterification reaction.

[0268] The method for producing the biodegradable polyester resin includes a step of subjecting the prepolymer to a polycondensation reaction. The polycondensation reaction can be carried out as follows.

[0269] The prepolymer is introduced into the polycondensation reaction section 300. Further, at least one or more of the reinforcing material, the heat stabilizer, the color corrector, the inorganic filler, the metal salt, or other additives may be introduced into the polycondensation reaction section 300 together with the prepolymer.

[0270] Thereafter, the polycondensation reaction can be carried out at about 180°C to about 280°C and about 10 torr or less for about 1 hour to about 5 hours. For example, the polycondensation reaction can be carried out at about 190°C to about 270°C, about 210°C to about 260°C, or about 230°C to about 255°C, and at about 0.9 torr or less, about 0.7 torr or less, about 0.2 torr to about 10 torr, about 0.2 torr to about 0.9 torr, or about 0.2 torr to about 0.6 torr, and can be carried out for about 1.5 hours to about 5 hours, about 2 hours to about 4.5 hours, or about 2 hours to about 4 hours.

[0271] Further, the polycondensation reaction may include a primary polycondensation and a secondary polycondensation.

[0272] For example, the primary polycondensation is carried out at about 260°C or less, about 250°C or less, about 215°C to about 250°C, about 215°C to about 245°C, or about 230°C to about 245°C, at about 1 torr to about 200 torr, about 2 torr to about 100 torr, about 4 torr to about 50 torr, about 5 torr to about 45 torr, or about 8 torr to about 32 torr, and can be carried out for about 0.5 hours to about 3.5 hours, about 0.5 hours to about 3.0 hours, or about 0.5 hours to about 2.8 hours.

[0273] Further, the secondary polycondensation is carried out at about 220°C to about 265°C, about 230°C to about 260°C, or about 235°C to about 255°C, at about 1 torr or less, about 0.8 torr or less, about 0.6 torr or less, about 0.1 torr to about 1 torr, about 0.2 torr to about 0.8 torr, or about 0.2 torr to about 0.6 torr, and can be carried out for about 0.5 hours to about 4 hours, about 1 hour to about 3.5 hours, or about 1.5 hours to about 3.5 hours.

[0274] Further, before the polycondensation reaction, a titanium-based catalyst or a germanium-based catalyst may be further added to the prepolymer. Also, before the polycondensation reaction, additives such as silica, potassium, or magnesium; amine-based stabilizers such as trimethyl phosphate, triphenyl phosphate, trimethyl phosphine, phosphoric acid, phosphorous acid, or tetraethylenepentamine; and one or more selected from the group consisting of polymerization catalysts such as antimony trioxide, antimony trioxide, or tetrabutyl titanate can be further added to the prepolymer.

[0275] The number average molecular weight of the polymer may be about 30,000 g / mol or more. For example, the number average molecular weight of the polymer may be about 33,000 g / mol or more, about 35,000 g / mol or more, or about 40,000 g / mol to about 90,000 g / mol. By the number average molecular weight of the polymer satisfying the above range, physical properties, impact resistance, durability, and moldability can be further improved.

[0276] Also, the second recovery unit 520 recovers reaction by-products such as water from the polycondensation reaction unit 300. The second recovery unit 520 can apply a vacuum pressure to the polycondensation reaction unit 300 to recover the by-products generated in the polycondensation reaction.

[0277] The second recovery unit 520 can apply a vacuum pressure of about 0.1 torr to about 1 torr inside the polycondensation reaction unit 300. The second recovery unit 520 can apply a vacuum pressure of about 0.1 torr to about 0.9 torr inside the polycondensation reaction unit 300.

[0278] Thereafter, the hydrolysis-resistant agent and / or the chain extender are added to the polymer. Thereafter, the polymer, the hydrolysis-resistant agent, and the chain extender are uniformly mixed and maintained at a temperature of about 200°C to about 260°C for about 1 minute to about 15 minutes. As a result, the polymer reacts with the hydrolysis-resistant agent and / or the chain extender.

[0279] In contrast, the hydrolysis-resistant agent and / or the chain extender can be added to the polycondensation reaction section 300 by a static mixer and react with the polymer. The reaction temperature of the hydrolysis-resistant agent and / or the chain extender in the polycondensation reaction section 300 may be about 200°C to about 260°C. Also, the reaction time of the hydrolysis-resistant agent and / or the chain extender in the polycondensation reaction section 300 may be about 1 minute to about 15 minutes.

[0280] The chain extender may have the same characteristics as described above.

[0281] As a result, the biodegradable polyester resin composition according to the examples may have an appropriate degree of hydrolysis and a high degree of biodegradability.

[0282] Thereafter, pellets can be produced from the polymer.

[0283] Specifically, after cooling the polymer to about 15°C or lower, about 10°C or lower, or about 6°C or lower, the cooled polymer can be cut to produce pellets. In contrast, the polymer can be cut at a temperature of about 40°C to about 60°C.

[0284] The cutting step can be carried out without limitation using any pellet cutting machine used in the industry, and the pellets may have various shapes. The pellet cutting method may include an underwater cutting method or a strand cutting method.

[0285] The pellets can undergo further post-treatment steps. The pellets can be introduced into the post-treatment section 400 to carry out the post-treatment steps.

[0286] The post-treatment process can be carried out within the post-treatment unit 400. The pellets are introduced into the post-treatment unit 400. Thereafter, the post-treatment unit 400 can melt the introduced pellets by frictional heat and extrude them again. That is, the post-treatment unit 400 may include an extruder such as a twin-screw extruder.

[0287] The post-treatment process temperature may be about 230°C to about 270°C. The post-treatment process temperature may be about 230°C to about 260°C. The post-treatment process temperature may be about 240°C to about 265°C. The post-treatment process temperature may be about 240°C to about 260°C.

[0288] The post-treatment process time may be about 30 seconds to about 3 minutes. The post-treatment process time may be about 50 seconds to about 2 minutes. The post-treatment process time may be about 1 minute to about 2 minutes.

[0289] Thereafter, the resin extruded by the extruder can be cooled, cut, and processed into post-treated pellets. That is, the resin extruded from the extruder can be reprocessed into pellets by the cutting step described above.

[0290] The crystallinity of the pellets can be improved in the post-treatment process. Also, the content of the residues contained in the pellets can be adjusted in the post-treatment process. In particular, the content of the oligomers contained in the pellets can be adjusted by the post-treatment process. The content of the residual solvent contained in the pellets can be adjusted by the post-treatment process.

[0291] Thereby, the post-treatment process can appropriately adjust the mechanical properties, biodegradability, UV resistance, optical properties, or hydrolysis resistance of the biodegradable polyester resin.

[0292] After the pellets are manufactured, the biodegradable polyester resin can be compounded with the two biodegradable polyester resins. Further, at least one or more of the inorganic filler, the light stabilizer, the color corrector, or the other additives can be compounded with the biodegradable polyester resin and the two biodegradable polyester resins.

[0293] The compounding step may be as follows.

[0294] The biodegradable polyester resin and the two biodegradable polyester resins are mixed with at least one or more of the inorganic filler, the heat stabilizer, the color corrector, the metal salt, or the other additives and then fed into an extruder. The mixed biodegradable polyester resin composition melts at a temperature of about 120°C to about 260°C in the extruder and mixes with each other. Thereafter, the melt-mixed biodegradable polyester resin composition is extruded, cooled, cut, and re-pelletized. Through such a process, it is possible to produce a biodegradable polyester resin composition according to an example by compounding with the two biodegradable polyester resins.

[0295] In contrast, the inorganic filler, the heat stabilizer, the color corrector, the metal salt, and the other additives can be added during the process of polymerizing the biodegradable polyester resin.

[0296] A biodegradable polyester film can be produced with the biodegradable polyester resin according to an example.

[0297] The thickness of the biodegradable polyester film may be about 5 μm to about 300 μm. For example, the thickness of the biodegradable polyester film may be about 5 μm to about 180 μm, about 5 μm to about 160 μm, about 10 μm to about 150 μm, about 15 μm to about 130 μm, about 20 μm to about 100 μm, about 25 μm to about 80 μm, or about 25 μm to about 60 μm.

[0298] The biodegradable polyester film according to the embodiment may have a hydrolysis degree and a biodegradation degree substantially the same as those of the biodegradable polyester resin composition described above.

[0299] On the other hand, the biodegradable polyester film can be manufactured using the biodegradable polyester resin or biodegradable polyester resin pellets.

[0300] Specifically, the method for manufacturing the biodegradable polyester film may include a step of manufacturing a biodegradable resin composition according to the embodiment and a step of drying and melt-extruding the biodegradable resin composition.

[0301] In the step of drying and melt-extruding the biodegradable resin composition, the drying can be performed at about 60°C to about 100°C for about 2 hours to about 12 hours. Specifically, the drying can be performed at about 65°C to about 95°C, about 70°C to about 90°C, or about 75°C to about 85°C for about 3 hours to about 12 hours or about 4 hours to about 10 hours. By satisfying the above range of the drying process conditions of the pellets, the quality of the manufactured biodegradable polyester film or molded product can be further improved.

[0302] In the step of drying and melt-extruding, the melt-extrusion can be performed at a temperature of about 270°C or lower. For example, the melt-extrusion can be performed at a temperature of about 265°C or lower, about 260°C or lower, about 255°C or lower, about 150°C to about 270°C, about 150°C to about 255°C, or about 150°C to about 240°C. The melt-extrusion can be performed in a blown film process. The melt-extrusion can be performed with a T-die.

[0303] Also, the film manufacturing process may be a calendaring process.

[0304] Biodegradable polyester molded product A biodegradable polyester molded product can be manufactured using the biodegradable polyester resin.

[0305] Specifically, the molded article can be manufactured by molding the biodegradable polyester resin composition by a known method in the industry, such as extrusion or injection. The molded article may be, but is not limited to, an injection molded article, an extrusion molded article, a thin film molded article, a blow molding or blow molded article, a 3D filament, an interior building material, etc.

[0306] For example, the molded article may be in the form of a film or sheet used for agricultural mulching films, disposable gloves, disposable films, disposable envelopes, food packaging materials, garbage bags by weight, etc., or may be in the form of fibers used for fabrics, knitted fabrics, non-woven fabrics, ropes, etc. Further, as shown in FIG. 2, the molded article may be in the form of a disposable container used for food packaging containers such as lunch boxes. Further, the molded article may be molded articles in various forms such as disposable straws, spoons, eating plates, forks, etc.

[0307] In particular, since the molded article can be formed from the biodegradable polyester resin which can improve not only physical properties such as impact absorption energy and hardness, but particularly impact resistance and durability, it can exhibit excellent characteristics when applied to packaging materials for products stored and transported at low temperatures, interior automotive materials requiring durability, garbage bags, mulching films, and disposable products.

[0308] The physical properties of the biodegradable film and the biodegradable molded article can be measured in a manner similar to that of the biodegradable polyester resin composition according to the examples.

[0309] That is, the biodegradable film and the biodegradable molded article can be measured by being processed by cutting, joining, grinding, etc. into a size similar to that of the sample measured by the biodegradable polyester resin composition according to the examples.

[0310] The biodegradable polyester resin composition according to the examples may have a molecular weight reduction rate of about 80% or more. The biodegradable polyester resin composition according to the examples may have a molecular weight reduction rate of about 85% or more. The biodegradable polyester resin composition according to the examples may have a molecular weight reduction rate of about 90% or more. In order to measure the molecular weight reduction rate, the biodegradable polyester resin composition was mixed with compost, and a biodegradation acceleration test was carried out at a temperature of 60 °C and a humidity of 90%. Using gel permeation chromatography (GPC), the number average molecular weight after 63 days was measured in the polyester resin compositions of the examples and comparative examples. The value obtained by dividing the difference between the initial number average molecular weight and the number average molecular weight after a certain period by the initial number average molecular weight was derived as the molecular weight reduction rate.

[0311] The molecular weight reduction rate can be derived by the following formula 1.

[0312] [Formula 1] JPEG2025523713000009.jpg12157

[0313] Here, the biodegradable polyester resin composition according to the examples is mixed with compost and undergoes a biodegradation acceleration test at a temperature of 60 °C and a humidity of 90% for about 63 days. Before the biodegradation acceleration test is carried out, the initial number average molecular weight of the biodegradable polyester resin composition and the number average molecular weight of the biodegradable polyester resin composition after 63 days of the biodegradation acceleration test are measured by gel permeation chromatography (GPC).

[0314] The molecular weight reduction rate was derived as the value obtained by dividing the difference between the initial number average molecular weight and the number average molecular weight after a certain period, for example, 63 days, by the initial number average molecular weight.

[0315] Also, the compost may contain about 40 wt% pig manure, about 15 wt% chicken manure, about 37 wt% large sawdust, about 5 wt% zeolite, and about 3 wt% microbial preparation.

[0316] Also, the manufacturer of the compost may be Taeheung F&G, and the product name of the compost may be native soil (by-product fertilizer grade 1 compost).

[0317] Also, when the reduction rate of the molecular weight is measured, the biodegradable polyester resin composition according to the examples is manufactured into a sheet having a thickness of about 300 μm. Thereafter, the manufactured sheet is cut into a size of about 3 cm × 3 cm to produce flakes. The flakes are mixed with the compost, and the biodegradation acceleration test is performed.

[0318] The biodegradable polyester film according to the examples may have a reduction rate of the molecular weight as described above. Similarly, the biodegradable polyester film according to the examples can be cut into a size of about 3 cm × 3 cm to produce flakes. The flakes can be mixed with the compost to perform the biodegradation acceleration test.

[0319] The biodegradable polyester resin composition according to the examples may have a biodegradation degree of about 80% or more. The biodegradable polyester resin composition according to the examples may have a biodegradation degree of about 85% or more. The biodegradable polyester resin composition according to the examples may have a biodegradation degree of about 90% or more. The biodegradation degree can be derived by the following formula 2.

[0320] [Formula 2] JPEG2025523713000010.jpg12165

[0321] The biodegradability of the biodegradable polyester resin composition according to the examples can be measured based on the amount of carbon dioxide generated in accordance with KS M3100-1. Specifically, a seeding source container containing only the compost produced in a compost plant is prepared, and a test container is prepared in which 5% by weight of the flakes of the biodegradable polyester resin composition are added to the compost based on the dry weight of the compost. Thereafter, the compost and the flakes are cultured for 180 days under the conditions of a temperature of 58 ± 2°C, a water content of 50%, and an oxygen concentration of 6% or more. The carbon dioxide generated in each container is collected, and the amount of carbon dioxide generated in each container is measured by titration with an aqueous solution of phenolphthalein. As shown in the above formula 2, the biodegradability was derived from the ratio of the carbon dioxide generated by the biodegradable polyester resin composition to the theoretically generated amount of carbon dioxide.

[0322] When the biodegradability is measured, the flakes of the biodegradable polyester resin composition can be produced substantially in the same manner as the flakes when the rate of decrease in the molecular weight is measured.

[0323] The biodegradable polyester film according to the examples may have the biodegradability as described above. Similarly, the biodegradable polyester film according to the examples is cut into a size of about 3 cm × 3 cm to produce flakes. The flakes can be mixed with the compost to perform the biodegradation test.

[0324] The degree of hydrolysis of the biodegradable polyester resin composition according to the examples can be measured by the following method.

[0325] In order to measure the degree of hydrolysis, the biodegradable resin composition according to the above examples is immersed in water at 80°C (100% RH), and then a hydrolysis acceleration test is performed. After a certain period of time has elapsed, the number average molecular weight of the biodegradable polyester resin composition according to the examples is measured using gel permeation chromatography (GPC). The degree of hydrolysis was derived from the value obtained by dividing the difference between the initial number average molecular weight and the number average molecular weight after hydrolysis for a certain period by the initial number average molecular weight.

[0326] The degree of hydrolysis may be represented by the following Mathematical Formula 3.

[0327] [Mathematical Formula 3] JPEG2025523713000011.jpg12147

[0328] Here, the biodegradable polyester resin composition according to the examples is immersed in water at 80° C. and then undergoes a hydrolysis acceleration test for a certain period. Before the hydrolysis acceleration test is performed, the initial number average molecular weight of the biodegradable polyester resin composition and the number average molecular weight after hydrolysis of the biodegradable polyester resin composition that has undergone the hydrolysis acceleration test for a certain period are measured by gel permeation chromatography (GPC).

[0329] The degree of hydrolysis is derived as a value obtained by dividing the difference between the initial number average molecular weight and the number average molecular weight after hydrolysis for a certain period by the initial number average molecular weight.

[0330] Also, when the degree of hydrolysis is measured, the biodegradable polyester resin composition according to the examples is produced into a sheet having a thickness of about 300 μm. Thereafter, the produced sheet is cut into a size of about 3 cm × 3 cm to produce flakes. The flakes can be immersed in the warm water to perform the hydrolysis acceleration test.

[0331] In the biodegradable polyester resin composition according to the examples, the degree of hydrolysis after 1 week may be about 40% to about 65%. In the biodegradable polyester resin composition according to the examples, the degree of hydrolysis after 1 week may be about 45% to about 63%.

[0332] In the biodegradable polyester resin composition according to the examples, the degree of hydrolysis after 2 weeks may be about 80% to about 93%. In the biodegradable polyester resin composition according to the examples, the degree of hydrolysis after 2 weeks may be about 85% to about 92%.

[0333] In the biodegradable polyester resin composition according to the examples, the degree of hydrolysis after 3 weeks may be about 90% to about 97%. In the biodegradable polyester resin composition according to the examples, the degree of hydrolysis after 3 weeks may be about 91% to about 96%.

[0334] In the biodegradable polyester resin composition according to the examples, the degree of hydrolysis after 4 weeks may be about 92% to about 99%. In the biodegradable polyester resin composition according to the examples, the degree of hydrolysis after 4 weeks may be about 93% to about 97%.

[0335] In the biodegradable polyester resin composition according to the examples, the degree of hydrolysis after 6 weeks may be about 94% or more. In the biodegradable polyester resin composition according to the examples, the degree of hydrolysis after 6 weeks may be about 95% or more.

[0336] In the biodegradable polyester resin composition according to the examples, the degree of hydrolysis after 9 weeks may be about 95% or more. In the biodegradable polyester resin composition according to the examples, the degree of hydrolysis after 9 weeks may be about 96% or more.

[0337] The biodegradable polyester resin composition according to the examples includes a weight swelling ratio. The weight swelling ratio may be a value obtained by dividing the difference between the weight after immersion in an organic solvent and the initial weight by the initial weight. When the weight swelling ratio is measured, the biodegradable polyester resin composition according to the examples may be processed into the form of the biodegradable polyester sheet described above and immersed in the solvent. Also, when the weight after immersion is measured, the solvent remaining on the surface of the biodegradable polyester sheet is sufficiently removed. Also, when the weight is measured after immersion, the biodegradable polyester sheet may be immersed in a solvent at room temperature.

[0338] The weight swelling ratio of the biodegradable polyester resin composition according to the example can be determined by the molecular structure of the biodegradable polyester resin, additives such as the nanocellulose, the metal salt or the polycarbonate diol, modifiers such as the chain extender or the hydrolysis resistant agent, and / or the polymerization process, etc.

[0339] The weight swelling ratio can be calculated by the following formula 4.

[0340] [Formula 4] JPEG2025523713000012.jpg17145

[0341] The biodegradable polyester resin composition according to the example may have a weight swelling ratio after being immersed in ethanol for 2 hours.

[0342] In the biodegradable polyester resin composition according to the example, the weight swelling ratio after being immersed in ethanol for 2 hours may be about 4% or more. In the biodegradable polyester resin composition according to the example, the weight swelling ratio after being immersed in ethanol for 2 hours may be about 4% to about 20%. In the biodegradable polyester resin composition according to the example, the weight swelling ratio after being immersed in ethanol for 2 hours may be about 6% to about 18%. In the biodegradable polyester resin composition according to the example, the weight swelling ratio after being immersed in ethanol for 2 hours may be about 8% to about 18%. In the biodegradable polyester resin composition according to the example, the weight swelling ratio after being immersed in ethanol for 2 hours may be about 10% to about 18%.

[0343] The biodegradable polyester resin composition according to the example may have a weight swelling ratio after being immersed in ethanol for 18 hours.

[0344] In the biodegradable polyester resin composition according to the example, the weight swelling ratio after immersion in ethanol for 18 hours may be about 4% or more. In the biodegradable polyester resin composition according to the example, the weight swelling ratio after immersion in ethanol for 18 hours may be about 4% to about 20%. In the biodegradable polyester resin composition according to the example, the weight swelling ratio after immersion in ethanol for 18 hours may be about 6% to about 18%. In the biodegradable polyester resin composition according to the example, the weight swelling ratio after immersion in ethanol for 18 hours may be about 8% to about 18%. In the biodegradable polyester resin composition according to the example, the weight swelling ratio after immersion in ethanol for 18 hours may be about 10% to about 18%.

[0345] The biodegradable polyester resin composition according to the example may have a weight swelling ratio after immersion in ethanol for 24 hours.

[0346] In the biodegradable polyester resin composition according to the example, the weight swelling ratio after immersion in ethanol for 24 hours may be about 4% or more. In the biodegradable polyester resin composition according to the example, the weight swelling ratio after immersion in ethanol for 24 hours may be about 4% to about 21%. In the biodegradable polyester resin composition according to the example, the weight swelling ratio after immersion in ethanol for 24 hours may be about 6% to about 19%. In the biodegradable polyester resin composition according to the example, the weight swelling ratio after immersion in ethanol for 24 hours may be about 8% to about 19%. In the biodegradable polyester resin composition according to the example, the weight swelling ratio after immersion in ethanol for 24 hours may be about 10% to about 19%.

[0347] In the biodegradable polyester resin composition according to the example, the difference between the weight swelling ratio after immersion in the ethanol for 2 hours and the weight swelling ratio after immersion in the ethanol for 18 hours may be about 6% or less. In the biodegradable polyester resin composition according to the example, the difference between the weight swelling ratio after immersion in the ethanol for 2 hours and the weight swelling ratio after immersion in the ethanol for 18 hours may be about 5% or less. In the biodegradable polyester resin composition according to the example, the difference between the weight swelling ratio after immersion in the ethanol for 2 hours and the weight swelling ratio after immersion in the ethanol for 18 hours may be about 4% or less.

[0348] Also, in the biodegradable polyester resin composition according to the example, the difference between the weight swelling ratio after immersion in the ethanol for 2 hours and the weight swelling ratio after immersion in the ethanol for 24 hours may be about 6% or less. In the biodegradable polyester resin composition according to the example, the difference between the weight swelling ratio after immersion in the ethanol for 2 hours and the weight swelling ratio after immersion in the ethanol for 24 hours may be about 5% or less. In the biodegradable polyester resin composition according to the example, the difference between the weight swelling ratio after immersion in the ethanol for 2 hours and the weight swelling ratio after immersion in the ethanol for 24 hours may be about 4% or less.

[0349] Also, the biodegradable polyester resin composition according to the example includes a volume swelling ratio. The volume swelling ratio may be a value obtained by dividing the difference between the volume after immersion in an organic solvent and the initial volume by the initial volume. When the volume swelling ratio is measured, the biodegradable polyester resin composition according to the example is processed into the form of the biodegradable polyester sheet described above and can be immersed in the solvent. Further, when the volume after immersion is measured, the solvent remaining on the surface of the biodegradable polyester sheet is sufficiently removed. Further, when the volume after immersion is measured, the biodegradable polyester sheet can be immersed in a solvent at room temperature.

[0350] The volume swelling ratio can be derived by the following mathematical formula 5.

[0351] [Mathematical Formula 5] JPEG2025523713000013.jpg17140

[0352] The biodegradable polyester resin composition according to the example may have a volume swelling ratio after being immersed in the ethanol for 2 hours.

[0353] In the biodegradable polyester resin composition according to the example, the volume swelling ratio after being immersed in the ethanol for 2 hours may be about 5% or more. In the biodegradable polyester resin composition according to the example, the volume swelling ratio after being immersed in the ethanol for 2 hours may be about 5% to about 20%. In the biodegradable polyester resin composition according to the example, the volume swelling ratio after being immersed in the ethanol for 2 hours may be 6% to about 20%. In the biodegradable polyester resin composition according to the example, the volume swelling ratio after being immersed in the ethanol for 2 hours may be about 8% to about 20%. In the biodegradable polyester resin composition according to the example, the volume swelling ratio after being immersed in the ethanol for 2 hours may be about 10% to about 20%.

[0354] The biodegradable polyester resin composition according to the example may have a volume swelling ratio after being immersed in the ethanol for 18 hours.

[0355] In the biodegradable polyester resin composition according to the example, the volume swelling ratio after being immersed in the ethanol for 18 hours may be about 5% or more. In the biodegradable polyester resin composition according to the example, the volume swelling ratio after being immersed in the ethanol for 18 hours may be about 5% to about 20%. In the biodegradable polyester resin composition according to the example, the volume swelling ratio after being immersed in the ethanol for 18 hours may be 6% to about 20%. In the biodegradable polyester resin composition according to the example, the volume swelling ratio after being immersed in the ethanol for 18 hours may be about 8% to about 20%. In the biodegradable polyester resin composition according to the example, the volume swelling ratio after being immersed in the ethanol for 18 hours may be about 10% to about 20%.

[0356] The biodegradable polyester resin composition according to the example may have a volume swelling ratio after being immersed in the ethanol for 24 hours.

[0357] In the biodegradable polyester resin composition according to the example, the volume swelling ratio after being immersed in the ethanol for 24 hours may be about 5% or more. In the biodegradable polyester resin composition according to the example, the volume swelling ratio after being immersed in the ethanol for 24 hours may be about 5% to about 20%. In the biodegradable polyester resin composition according to the example, the volume swelling ratio after being immersed in the ethanol for 24 hours may be 6% to about 20%. In the biodegradable polyester resin composition according to the example, the volume swelling ratio after being immersed in the ethanol for 24 hours may be about 8% to about 20%. In the biodegradable polyester resin composition according to the example, the volume swelling ratio after being immersed in the ethanol for 24 hours may be about 10% to about 20%.

[0358] In the biodegradable polyester resin composition according to the example, the difference between the volume swelling ratio after being immersed in the ethanol for 2 hours and the volume swelling ratio after being immersed in the ethanol for 18 hours may be about 8% or less. In the biodegradable polyester resin composition according to the example, the difference between the volume swelling ratio after being immersed in the ethanol for 2 hours and the volume swelling ratio after being immersed in the ethanol for 18 hours may be about 6% or less. In the biodegradable polyester resin composition according to the example, the difference between the volume swelling ratio after being immersed in the ethanol for 2 hours and the volume swelling ratio after being immersed in the ethanol for 18 hours may be about 5% or less.

[0359] Also, in the biodegradable polyester resin composition according to the examples, the difference between the volume swelling ratio after immersion in the ethanol for 2 hours and the volume swelling ratio after immersion in the ethanol for 24 hours may be about 8% or less. In the biodegradable polyester resin composition according to the examples, the difference between the volume swelling ratio after immersion in the ethanol for 2 hours and the volume swelling ratio after immersion in the ethanol for 24 hours may be about 6% or less. In the biodegradable polyester resin composition according to the examples, the difference between the volume swelling ratio after immersion in the ethanol for 2 hours and the volume swelling ratio after immersion in the ethanol for 24 hours may be about 5% or less.

[0360] The biodegradable polyester resin composition according to the examples may have a wet hardness reduction rate. The wet hardness reduction rate is a value obtained by dividing the difference between the initial hardness before immersion and the wet hardness after immersion by the initial hardness after the biodegradable polyester resin composition is immersed in water at a constant temperature for a constant time.

[0361] The wet hardness reduction rate can be derived by the following formula 6.

[0362] [Formula 6] JPEG2025523713000014.jpg15147

[0363] In the biodegradable polyester resin composition according to the examples, the wet hardness reduction rate after immersion at a temperature of about 30°C for about 24 hours may be about 16% or less. The wet hardness reduction rate after immersion at the temperature of 30°C for about 24 hours may be about 15% or less. The wet hardness reduction rate after immersion at the temperature of 30°C for 24 hours may be about 14% or less. The wet hardness reduction rate after immersion at the temperature of 30°C for 24 hours may be about 13% or less. The wet hardness reduction rate after immersion at the temperature of 30°C for 24 hours may be about 12% or less. The minimum value of the wet hardness reduction rate after immersion at the temperature of 30°C for 24 hours may be about 1%, about 3%, about 5% or about 6%.

[0364] The rate of decrease in wet hardness after immersion at the temperature of 30°C for 24 hours may be measured by the following measuring method. First, the biodegradable polyester resin composition is processed to produce a polyester block having a thickness of about 2.5 mm. The initial hardness of the polyester block is measured before immersion, and after the polyester block is immersed in water at about 30°C for about 24 hours, the wet hardness of the polyester block is immediately measured. Thereafter, the rate of decrease in wet hardness after immersion at the temperature of 30°C for 24 hours can be derived by the following Formula 4.

[0365] The biodegradable polyester resin composition can be dried at a temperature of about 80°C for about 20 minutes at a moisture content of about 500 ppm, placed in a stainless steel frame, and compressed at a temperature of about 210°C and a pressure of about 10 MPa for about 5 minutes to produce a polyester block having a thickness of about 2.5 mm.

[0366] The initial hardness may be about 30 to about 45 in Shore D hardness. The initial hardness may be about 33 to about 43 in Shore D hardness. The initial hardness may be about 35 to about 41 in Shore D hardness.

[0367] The wet hardness after immersion at the temperature of 30°C for 24 hours may be about 28 to about 43 in Shore D hardness. The wet hardness after immersion at the temperature of 30°C for 24 hours may be about 29 to about 41 in Shore D hardness. The wet hardness after immersion at the temperature of 30°C for 1 hour may be about 30 to about 38 in Shore D hardness.

[0368] The rate of decrease in wet hardness after immersion at a temperature of 30°C for 0.5 hours may be about 16% or less. The rate of decrease in wet hardness after immersion at a temperature of 30°C for 0.5 hours may be about 15% or less. The rate of decrease in wet hardness after immersion at a temperature of 30°C for 0.5 hours may be about 14% or less. The rate of decrease in wet hardness after immersion at a temperature of 30°C for 0.5 hours may be about 13% or less. The rate of decrease in wet hardness after immersion at a temperature of 30°C for 0.5 hours may be about 12% or less. The minimum value of the rate of decrease in wet hardness after immersion at a temperature of 30°C for 0.5 hours may be about 1%, about 3%, about 5% or about 6%.

[0369] The wet hardness after immersion at a temperature of 30°C for 0.5 hours may be about 28 to about 43 in Shore D hardness. The wet hardness after immersion at a temperature of 30°C for 0.5 hours may be about 29 to about 41 in Shore D hardness. The wet hardness after immersion at a temperature of 30°C for 0.5 hours may be about 30 to about 39 in Shore D hardness.

[0370] The deviation between the rate of decrease in wet hardness after immersion at a temperature of 30°C for 24 hours and the rate of decrease in wet hardness after immersion at a temperature of 30°C for 0.5 hours may be about 10% or less. The deviation between the rate of decrease in wet hardness after immersion at a temperature of 30°C for 24 hours and the rate of decrease in wet hardness after immersion at a temperature of 30°C for 0.5 hours is the value obtained by dividing the absolute value of the difference between the wet hardness after immersion at a temperature of 30°C for 24 hours and the wet hardness after immersion at a temperature of 30°C for 0.5 hours by the initial hardness. The deviation between the rate of decrease in wet hardness after immersion at a temperature of 30°C for 24 hours and the rate of decrease in wet hardness after immersion at a temperature of 30°C for 0.5 hours may be about 7% or less. The deviation between the rate of decrease in wet hardness after immersion at a temperature of 30°C for 24 hours and the rate of decrease in wet hardness after immersion at a temperature of 30°C for 0.5 hours may be about 5% or less.

[0371] The rate of decrease in wet hardness after immersion at a temperature of 30°C for 1 hour may be about 16% or less. The rate of decrease in wet hardness after immersion at a temperature of 30°C for 1 hour may be about 15% or less. The rate of decrease in wet hardness after immersion at a temperature of 30°C for 24 hours may be about 14% or less. The rate of decrease in wet hardness after immersion at a temperature of 30°C for 24 hours may be about 13% or less. The rate of decrease in wet hardness after immersion at a temperature of 30°C for 24 hours may be about 12% or less. The minimum value of the rate of decrease in wet hardness after immersion at a temperature of 30°C for 1 hour may be about 1%, about 3%, about 5% or about 6%.

[0372] The wet hardness after immersion at a temperature of 30°C for 1 hour may be about 28 to about 43 in Shore D hardness. The wet hardness after immersion at a temperature of 30°C for 1 hour may be about 29 to about 41 in Shore D hardness. The wet hardness after immersion at a temperature of 30°C for 1 hour may be about 30 to about 39 in Shore D hardness.

[0373] The deviation between the rate of decrease in wet hardness after immersion at a temperature of 30°C for 1 hour and the rate of decrease in wet hardness after immersion at a temperature of 30°C for 24 hours may be about 10% or less. The deviation between the rate of decrease in wet hardness after immersion at a temperature of 30°C for 1 hour and the rate of decrease in wet hardness after immersion at a temperature of 30°C for 24 hours may be about 7% or less. The deviation between the rate of decrease in wet hardness after immersion at a temperature of 30°C for 1 hour and the rate of decrease in wet hardness after immersion at a temperature of 30°C for 24 hours may be about 5% or less.

[0374] The rate of decrease in wet hardness after immersion at a temperature of 30°C for 18 hours may be about 16% or less. The rate of decrease in wet hardness after immersion at a temperature of 30°C for 18 hours may be about 15% or less. The rate of decrease in wet hardness after immersion at a temperature of 30°C for 18 hours may be about 14% or less. The rate of decrease in wet hardness after immersion at a temperature of 30°C for 18 hours may be about 13% or less. The rate of decrease in wet hardness after immersion at a temperature of 30°C for 18 hours may be about 12% or less. The minimum value of the rate of decrease in wet hardness after immersion at a temperature of 30°C for 18 hours may be about 1%, about 3%, about 5% or about 6%.

[0375] The wet hardness after immersion at the temperature of 30°C for 18 hours may be about 28 to about 43 in Shore D hardness. The wet hardness after immersion at the temperature of 30°C for 18 hours may be about 29 to about 41 in Shore D hardness. The wet hardness after immersion at the temperature of 30°C for 18 hours may be about 30 to about 39 in Shore D hardness.

[0376] The deviation between the wet hardness reduction rate after immersion at the temperature of 30°C for 24 hours and the wet hardness reduction rate after immersion at the temperature of 30°C for 18 hours may be about 10% or less. The deviation between the wet hardness reduction rate after immersion at the temperature of 30°C for 24 hours and the wet hardness reduction rate after immersion at the temperature of 30°C for 18 hours may be about 7% or less. The deviation between the wet hardness reduction rate after immersion at the temperature of 30°C for 24 hours and the wet hardness reduction rate after immersion at the temperature of 30°C for 18 hours may be about 5% or less.

[0377] The wet hardness reduction rate after immersion at the temperature of about 50°C for 24 hours may be about 16% or less. The wet hardness reduction rate after immersion at the temperature of 50°C for 24 hours may be about 15% or less. The wet hardness reduction rate after immersion at the temperature of 50°C for 24 hours may be about 14% or less. The wet hardness reduction rate after immersion at the temperature of 50°C for 24 hours may be about 13% or less. The wet hardness reduction rate after immersion at the temperature of 50°C for 24 hours may be about 12% or less. The minimum value of the wet hardness reduction rate after immersion at the temperature of 50°C for 24 hours may be about 1%, about 3%, about 5% or about 6%.

[0378] The wet hardness after immersion at the temperature of 50°C for 24 hours may be about 28 to about 43 in Shore D hardness. The wet hardness after immersion at the temperature of 50°C for 24 hours may be about 29 to about 41 in Shore D hardness. The wet hardness after immersion at the temperature of 50°C for 24 hours may be about 30 to about 39 in Shore D hardness.

[0379] The deviation between the wet hardness reduction rate after immersion at a temperature of 30°C for 24 hours and the wet hardness reduction rate after immersion at a temperature of 50°C for 24 hours may be about 10% or less. The deviation between the wet hardness reduction rate after immersion at a temperature of 30°C for 24 hours and the wet hardness reduction rate after immersion at a temperature of 50°C for 24 hours may be about 7% or less. The deviation between the wet hardness reduction rate after immersion at a temperature of 30°C for 24 hours and the wet hardness reduction rate after immersion at a temperature of 50°C for 24 hours may be about 5% or less.

[0380] The wet hardness reduction rate after immersion at a temperature of 70°C for 24 hours may be about 16% or less. The wet hardness reduction rate after immersion at a temperature of 70°C for 24 hours may be about 15%. The wet hardness reduction rate after immersion at a temperature of 70°C for 24 hours may be about 14% or less. The wet hardness reduction rate after immersion at a temperature of 70°C for 24 hours may be about 13% or less. The wet hardness reduction rate after immersion at a temperature of 50°C for 24 hours may be about 12% or less. The minimum value of the wet hardness reduction rate after immersion at a temperature of 50°C for 24 hours may be about 1%, about 3%, about 5% or about 6%.

[0381] The wet hardness after immersion at a temperature of 70°C for 24 hours may be about 28 to about 43 in Shore D hardness. The wet hardness after immersion at a temperature of 70°C for 24 hours may be about 29 to about 41 in Shore D hardness. The wet hardness after immersion at a temperature of 70°C for 1 hour may be about 30 to about 39 in Shore D hardness.

[0382] The deviation between the wet hardness reduction rate after immersion at a temperature of 30°C for 24 hours and the wet hardness reduction rate after immersion at a temperature of 70°C for 24 hours may be about 10% or less. The deviation between the wet hardness reduction rate after immersion at a temperature of 30°C for 24 hours and the wet hardness reduction rate after immersion at a temperature of 70°C for 24 hours may be about 7% or less. The deviation between the wet hardness reduction rate after immersion at a temperature of 30°C for 24 hours and the wet hardness reduction rate after immersion at a temperature of 70°C for 24 hours may be about 5% or less.

[0383] Also, the acid value of the biodegradable polyester resin composition according to the examples may be from about 0.01 mgKOH / g to about 3 mgKOH / g. The acid value of the biodegradable polyester resin composition according to the examples may be from about 0.1 mgKOH / g to about 2.5 mgKOH / g. The acid value of the biodegradable polyester resin composition according to the examples may be from about 0.1 mgKOH / g to about 2.3 mgKOH / g.

[0384] Since the biodegradable polyester resin composition according to the examples has an acid value in the above range, it may have the hydrolysis degree characteristics and biodegradability characteristics as described above.

[0385] Also, the biodegradable polyester resin composition according to the examples may contain a silicon element. The silicon element may be derived from the hydrolysis-resistant agent or the like. The content of the silicon element may be from about 0.1 ppm to about 1000 ppm based on the biodegradable polyester resin composition according to the examples. The content of the silicon element may be from about 0.5 ppm to about 500 ppm based on the biodegradable polyester resin composition according to the examples. The content of the silicon element may be from about 1 ppm to about 100 ppm based on the biodegradable polyester resin composition according to the examples. The content of the silicon element may be from about 1 ppm to about 50 ppm based on the biodegradable polyester resin composition according to the examples.

[0386] In addition, the biodegradable polyester resin composition according to the examples may contain a metal element. The metal element may be derived from the metal salt. The content of the metal element may be about 0.1 ppm to about 200 ppm based on the biodegradable polyester resin composition according to the examples. The content of the metal element may be about 0.5 ppm to about 150 ppm based on the biodegradable polyester resin composition according to the examples. The content of the metal element may be about 1 ppm to about 100 ppm based on the biodegradable polyester resin composition according to the examples. The content of the metal element may be about 1 ppm to about 50 ppm based on the biodegradable polyester resin composition according to the examples.

[0387] In addition, the biodegradable polyester resin composition according to the examples may contain an iron element. The iron element may be derived from the metal salt. The content of the iron element may be about 0.1 ppm to about 200 ppm based on the biodegradable polyester resin composition according to the examples. The content of the iron element may be about 0.5 ppm to about 150 ppm based on the biodegradable polyester resin composition according to the examples. The content of the iron element may be about 1 ppm to about 100 ppm based on the biodegradable polyester resin composition according to the examples. The content of the iron element may be about 1 ppm to about 50 ppm based on the biodegradable polyester resin composition according to the examples.

[0388] In addition, the ratio of the content of the iron element to the content of the silicon element (ppm content of iron element / ppm content of silicon element) may be about 0.1 to about 0.8. The ratio of the content of the iron element to the content of the silicon element (ppm content of iron element / ppm content of silicon element) may be about 0.1 to about 0.7. The ratio of the content of the iron element to the content of the silicon element (ppm content of iron element / ppm content of silicon element) may be about 0.3 to about 0.7. The ratio of the content of the iron element to the content of the silicon element (ppm content of iron element / ppm content of silicon element) may be about 0.35 to about 0.65.

[0389] The biodegradable polyester resin composition according to the embodiment may have appropriate solvent resistance, appropriate hydrolysis degree, and appropriate biodegradability because it contains silicon element and iron element within the above ranges. In particular, the hydrolysis degree may be appropriately adjusted by the content of the silicon element, and the biodegradability may be appropriately adjusted by the content of the iron element.

[0390] The contents of the silicon element and the metal may be measured by Inductively Coupled Plasma Optical Emission Spectroscopy.

[0391] In the biodegradable polyester resin composition according to the embodiment, the first weight swelling ratio is 4% to 20%. The biodegradable polyester resin composition according to the embodiment may have an appropriate swelling ratio in an organic solvent such as ethanol. That is, the biodegradable polyester resin composition according to the embodiment may have appropriate solvent properties with respect to the organic solvent.

[0392] Thereby, molded articles such as films made of the biodegradable polyester resin composition according to the embodiment can be easily printed with the ink containing the organic solvent. That is, the ink can appropriately penetrate into the surface of the molded article containing the biodegradable polyester resin composition according to the embodiment by the organic solvent. Thereby, the biodegradable polyester resin composition according to the embodiment may have improved printability.

[0393] Also, in the biodegradable polyester resin composition according to the embodiment, the wet hardness reduction rate is 15% or less. Thereby, the biodegradable polyester resin composition according to the embodiment may have high moisture resistance. The biodegradable polyester resin composition according to the embodiment can maintain high mechanical properties even when exposed to water or in a high-humidity environment.

[0394] The biodegradable polyester resin composition according to the embodiment may have appropriate hydrophobicity. As a result, the biodegradable polyester resin composition according to the embodiment may have high moisture resistance. The biodegradable polyester resin composition according to the embodiment can maintain high mechanical properties even when exposed to water or in a high-humidity environment.

[0395] As a result, when the biodegradable polyester resin composition according to the embodiment is used for packaging foods with a lot of moisture, etc., it may have little change in mechanical properties.

[0396] Also, the biodegradable polyester resin composition according to the embodiment may have hydrophobic properties. As a result, the biodegradable polyester resin composition according to the embodiment can absorb a little moisture in the air. As a result, the biodegradable polyester resin composition according to the embodiment may have improved storage stability.

[0397] The biodegradable polyester resin composition according to the embodiment may contain a silicon-based hydrolysis-resistant agent. As a result, the biodegradable polyester resin composition according to the embodiment may have improved hydrolysis resistance. Also, the silicon-based hydrolysis-resistant agent can function as a coupling agent that couples the polymer resin contained in the polycondensation composition.

[0398] As a result, the silicon-based hydrolysis-resistant agent can improve the degree of polymerization of the biodegradable polyester resin composition according to the embodiment.

[0399] As a result, the biodegradable polyester resin composition according to the embodiment has improved physical properties during the actual use period and can be easily biodegraded after use.

[0400] The biodegradable polyester resin composition according to the examples can be efficiently applied to packaging films and the like. That is, the film produced from the biodegradable polyester resin composition according to the examples is used for normal applications such as packaging. At this time, the biodegradable polyester resin composition according to the examples may initially have a low degree of hydrolysis, and within the normal usage period of the user, the biodegradable polyester film can maintain mechanical and chemical physical properties to a certain extent or more.

[0401] At the same time, since the biodegradable polyester resin composition according to the examples has a high degree of biodegradability, the film produced from the biodegradable polyester resin composition according to the examples can be easily decomposed when discarded after use.

[0402] The above content will be described in more detail with reference to the following examples. However, the following examples are for illustrative purposes of the present invention, and the scope of the examples is not limited thereto.

[0403] <Production Example> Production of Pretreated Cellulose Nanocrystals Cellulose nanocrystals (NVC-100, manufacturer: Celluforce) in the form of dry powder having a particle size of about 1 μm to about 50 μm were dispersed in water at 1 wt%, and then ultrasonic treatment was performed for 1 minute at an output of 20,000 J / s using a tip-type ultrasonic disperser to produce pretreated nanocellulose.

[0404] Hydrolysis-resistant agent #1: 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane (2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, Shin-Etsu KBM-303) Hydrolysis-resistant agent #2: 3-glycidyloxypropyltriethoxysilane (γ-Glycidyloxypropyltriethoxysilane) Metal salt: Iron(II) acetate Polycarbonate diol #1 (Nippon Polyurethane Industry, N-965, weight average molecular weight of about 1000) Polycarbonate diol #2 (RAVECARB 106, Caffaro Industrie)

[0405] <Example> Example 1 Production of biodegradable polyester resin First stage: The stage of obtaining a slurry through pretreatment As shown in Table 1, the pretreated nanocellulose, iron(II) acetate, 1,4-butanediol (1,4-BDO), and terephthalic acid (TPA) were mixed at a molar ratio of (1,4-BDO:TPA) of 1.2:1, and without a catalyst, they were charged into a slurry tank (the bottom of the slurry tank is of the anchor type, the height to the agitator is 40 mm, and it is equipped with three rotating blades). At this time, the D50 of the terephthalic acid (TPA) was 130 μm.

[0406] At this time, the contents of the nanocellulose and the iron(II) acetate were as shown in Table 1 below based on the total weight of the terephthalic acid, 1,4-butanediol, and adipic acid charged.

[0407] Next, the mixture was stirred at 60 °C and 100 rpm for 1 hour for pretreatment to obtain a slurry without phase separation.

[0408] Second stage: The stage of obtaining a prepolymer The slurry obtained in the first stage was charged into a reactor through a supply line, and 250 ppm of tetrabutyl titanate (manufactured by Dupont, Tyzor TnBT), which is a titanium-based catalyst, was added. Then, a primary esterification reaction was carried out at 220 °C and atmospheric pressure for about 2 hours until 95% of the by-product water was discharged.

[0409] Based on the total molar amount of the diol component, 53 mol% of 1,4-butanediol (1,4-BDO), based on the total molar amount of the dicarboxylic acid component, 53 mol% of adipic acid (AA), a polycarbonate diol and a titanium-based catalyst tetrabutyl titanate (manufactured by Dupont, Tyzor TnBT) were added at 200 ppm based on the total weight of the diol, aromatic dicarboxylic acid and aliphatic dicarboxylic acid. Then, at 210 °C and normal pressure, a secondary esterification reaction was carried out for about 2 hours and 30 minutes until 95% of the by-product water was discharged, and a prepolymer having a number average molecular weight of 1200 g / mol was produced. The content of the polycarbonate diol is as shown in Table 1 below based on 100 parts by weight of the total of terephthalic acid, 1,4-butanediol and adipic acid introduced.

[0410] Step 3: Step of carrying out polycondensation reaction 400 ppm of a titanium-based catalyst tetrabutyl titanate (manufactured by Dupont, Tyzor TnBT) and 200 ppm of a triethylene phosphate stabilizer were added to the prepolymer based on the total weight of the prepolymer and stabilized for about 10 minutes. Then, after raising the temperature of the reaction mixture to 250 °C, a polycondensation reaction was carried out at 0.5 torr for 4 hours to produce a polymer having a number average molecular weight of 55000 g / mol.

[0411] Then, based on 100 parts by weight of the polymer, about 0.1 part by weight of a hydrolysis-resistant agent was added to the polymer. Then, the polymer was subjected to a coupling reaction at a temperature of about 250 °C for about 10 minutes. Then, after cooling this to 5 °C, it was cut with a pellet cutter to obtain biodegradable polyester resin pellets.

[0412] Examples 2 to 6 As shown in Table 1 below, the contents of adipic acid, terephthalic acid, cellulose nanocrystal, and hydrolysis-resistant agent are different. Except for the said content and the said process, other processes were carried out substantially with reference to Example 1.

[0413] Examples 7 to 13 and Comparative Examples As shown in Table 2 below, the contents of adipic acid, terephthalic acid, cellulose nanocrystal, and hydrolysis-resistant agent are different. Except for the said contents and the said steps, other steps were carried out substantially with reference to Example 1.

[0414] Manufacture of Biodegradable Polyester Sheet After preparing two Teflon sheets, a stainless steel (SUS) frame (area 12 cm × 12 cm) was positioned on one Teflon sheet, and after putting about 7 g of the manufactured polyester resin pellets into the stainless steel (SUS) frame (area 12 cm × 12 cm), it was covered with the other Teflon sheet and positioned at the center of a hot press (manufacturer: Withrap, model name: WL1600SA) having a surface size of about 25 cm × 25 cm. This was maintained at about 210 °C under a pressure of about 10 Mpa for about 3 minutes, then detached, and immediately cooled with water at about 20 °C for about 30 seconds, and a biodegradable polyester sheet with an area of about 10 cm × 10 cm and a thickness of about 300 μm was manufactured.

[0415] Manufacture of Biodegradable Polyester Film After drying the biodegradable polyester resin pellets at 80 °C for 5 hours, they were melt-extruded at 160 °C using a blown film extrusion line (manufacturer: Ujin Engineering) to manufacture a biodegradable polyester film with a thickness of 50 μm.

[0416]

Table 1

[0417]

Table 2

[0418] <Evaluation Example> Evaluation Example 1: Average Particle Size (D50) and Standard Deviation <Average Particle Size (D50) and Standard Deviation of Aromatic Dicarboxylic Acid> The average particle size (D50) and standard deviation (SD) of aromatic dicarboxylic acids (TPA or DMT) were determined under the following conditions using a particle size analyzer Microtrac S3500 (Microtrac Inc) in the particle size distribution (PSD): Use environment - Temperature: 10 - 35 °C, Humidity: 90%RH, non - condensing maximum - D50 and SD, which are the average particle size distributions by interval, were measured.

[0419] The standard deviation means the square root of the variance and can be calculated using software.

[0420] <Particle size of nanocellulose> For nanocellulose, using a Zetasizer Nano ZS (manufacturer: Marven), the particle size and particle size deviation were measured by the principle of dynamic light scattering (DLS) at a temperature of 25 °C and a measurement angle of 175 °. At this time, the peak value derived from the polydispersity index (PdI) in the confidence interval of 0.5 was measured as the particle size.

[0421] Evaluation Example 2: Degree of hydrolysis The biodegradable polyester resins produced in the examples and comparative examples were immersed in water at 80 °C (100% RH), and then a hydrolysis acceleration test was carried out.

[0422] Specifically, 5 g of the polyester resins of the examples and comparative examples were put into 500 mL of deionized water (DI Water), then blocked with a stopper so that the water would not evaporate, and a hydrolysis acceleration test was carried out at 80 °C in a convection (hot air) oven. The humidity environment of the biodegradable polyester sheet is the same as when immersed in water at 100% RH.

[0423] Using gel permeation chromatography (GPC), the number average molecular weight of the polyester resins of the examples and comparative examples was measured after a certain period of time. The value obtained by dividing the difference between the initial number average molecular weight and the number average molecular weight after a certain period of time by the initial number average molecular weight was derived as the hydrolysis degree.

[0424] The GPC equipment and measurement conditions are as follows. Sample pretreatment: Dissolve 0.035 mg of PBAT chip in 1.5 ml of THF Measuring device: e2695 from Waters Injection rate (Flow rate): 1 ml / min in THF Injection volume: 50 μl Column temperature (Column Temp): 40 °C Detector: ELSD Column: Styragel Column HR 5E, HR4, HR2

[0425] Evaluation Example 3: Biodegradability The biodegradable polyester resins produced in the examples and comparative examples were mixed with the following compost, and a biodegradation acceleration test was carried out at a temperature of 60 °C and a humidity of 90%.

[0426] Using the gel permeation chromatography (GPC), the number average molecular weight of the polyester resins of the examples and comparative examples was measured after a certain period of time. The value obtained by dividing the difference between the initial number average molecular weight and the number average molecular weight after a certain period of time by the initial number average molecular weight was derived as the biodegradability.

[0427] Compost Manufacturer: Taeheung F&G Product name: Native soil (by-product fertilizer grade 1 compost) Compost composition components: 40 wt% pig manure, 15 wt% chicken manure, 37 wt% large sawdust, 5 wt% zeolite, 3 wt% microbial preparation

[0428] Evaluation Example 5: Swelling ratio A polyester sheet with its initial weight and initial thickness measured was immersed in ethanol at room temperature, and after 2 hours, 18 hours, and 24 hours had passed, it was taken out from each solvent. Then, the weight and thickness of the polyester sheet with the surface solvent removed were measured. Based on the changes in the weight and thickness, the weight swelling ratio and volume swelling ratio were measured.

[0429] Evaluation Example 6: Water Contact Angle and Polarity On the surface of the biodegradable polyester sheets produced in the examples and comparative examples, the water contact angle and polarity are measured under the following conditions.

[0430] Surface Tension: Wetting Tension Test Mixture Nos. 40 - 64 Manufacturer: Wako Components: Ethylene Glycol, Monoethyl Ether Surface Energy Measuring Instrument: MSA One - Click SFE (Product Name) / KRUSS (Manufacturer)

[0431] Evaluation Example 7: Iron and Silicon Contents The biodegradable polyester pellets produced in the examples and comparative examples were dissolved in a 65 wt% nitric acid solution, and the iron and silicon contents were measured by ICP OES.

[0432] Apparatus: Agilent 5110 SVDV Measurement Conditions RF power: 1.2 KW Nebulizer flow: 0.7 L / min Plasma flow: 12 L / min Aux flow: 1 L / min Read time: 5 s

[0433] As described in Tables 3 and 4 below, the degree of hydrolysis was measured.

[0434]

Table 3

[0435]

Table 4

[0436] As shown in Table 5 and Table 6 below, the molecular weight reduction rate and biodegradability have been derived.

[0437]

Table 5

[0438]

Table 6

[0439] As shown in Table 7 and Table 8 below, the iron element content and silicon element content have been measured.

[0440]

Table 7

[0441]

Table 8

[0442] As described in Table 9 and Table 10 below, the weight swelling rate and volume swelling rate with respect to ethanol immersion time have been measured.

[0443]

Table 9

[0444]

Table 10

[0445] As described in Table 11 - 13 below, the initial hardness and the wet hardness for each temperature and each immersion time have been measured.

[0446]

Table 11

[0447]

Table 12

[0448]

Table 13

[0449] As described in Tables 14 and 15 below, the surface properties of the biodegradable polyester sheets produced by the examples and comparative examples have been derived.

[0450]

Table 14

[0451]

Table 15

[0452] As described in Tables 3 to 15 above, the biodegradable resin composition according to the examples may have appropriate degrees of hydrolysis and biodegradability.

[0453] Also, as described in Tables 3 to 15 above, the biodegradable resin composition according to the examples has appropriate weight swelling ratios and volume swelling ratios, and has appropriate surface properties.

[0454] Also, as described in Tables 3 to 15 above, it was found that the biodegradable resin composition according to the examples has an appropriate rate of change in wet hardness and appropriate surface properties.

Industrial Applicability

[0455] The examples can be used for biodegradable resin compositions, films, and molded articles.

Claims

1. A biodegradable polyester resin composition comprising a polyester resin containing a diol, an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid, wherein the first weight swelling ratio is 4% to 20%, and the first weight swelling ratio is measured by the following measurement method: A biodegradable polyester resin composition. [Measurement method] The biodegradable polyester resin composition is dried at a temperature of 80 °C, placed in a stainless steel frame, compressed at a temperature of 210 °C and a pressure of 10 MPa for 3 minutes to produce a polyester sheet having a thickness of 300 μm. The initial weight of the polyester sheet and the weight of the polyester sheet after being immersed in ethanol at room temperature for 2 hours are measured. The first weight swelling ratio is a value obtained by dividing the difference between the weight after immersion and the initial weight by the initial weight.

2. wherein the volume swelling ratio is 5% to 20%, and the volume swelling ratio is measured by the following measurement method: The biodegradable polyester resin composition according to Claim 1. [Measurement method] The initial volume of the polyester sheet and the volume of the polyester sheet after being immersed in ethanol at room temperature for 2 hours are measured. The volume swelling ratio is a value obtained by dividing the difference between the volume after immersion and the initial volume by the initial volume.

3. wherein the silicon element content is 0.1 ppm to 1000 ppm, The biodegradable polyester resin composition according to Claim 1.

4. wherein the water contact angle on the surface of the polyester sheet is 45° to 85°, The biodegradable polyester resin composition according to Claim 1.

5. wherein the polarity degree on the surface of the polyester sheet is 3 mN / m to 5 mN / m, The biodegradable polyester resin composition according to Claim 4.

6. further comprising a metal, The biodegradable polyester resin composition according to Claim 3.

7. wherein the metal contains an iron element, and the ratio of the iron element to the silicon element is 0.1 to 0.7, The biodegradable polyester resin composition according to Claim 6.

8. wherein the degree of hydrolysis after 1 week is 35% to 60%, and the degree of hydrolysis after 3 weeks is 85% or more, and the degree of hydrolysis after 1 week and the degree of hydrolysis after 3 weeks are measured by the following measurement method: The biodegradable polyester resin composition according to Claim 1. [Measurement method] The degree of hydrolysis after one week is the reduction rate of the number average molecular weight of the biodegradable polyester resin composition with respect to the initial value when the biodegradable polyester resin composition is placed for one week under high temperature and high humidity conditions of a temperature of 80 ° C and a humidity of 100%. The degree of hydrolysis after three weeks is the reduction rate of the number average molecular weight of the biodegradable polyester resin composition with respect to the initial value when the biodegradable polyester resin composition is placed for three weeks under high temperature and high humidity conditions of a temperature of 80 ° C and a humidity of 100%.

9. The second weight swelling ratio is 4% to 20%. The second weight swelling ratio is measured by the following measurement method. The biodegradable polyester resin composition according to claim 1. [Measurement method] The initial weight of the polyester sheet and the weight of the polyester sheet after being immersed in ethanol at room temperature for 24 hours are measured. The second weight swelling ratio is the value obtained by dividing the difference between the weight after immersion and the initial weight by the initial weight.

10. The difference between the first weight swelling ratio and the second swelling ratio is 5% or less. The polyester resin composition according to claim 9.

11. It contains a polyester resin containing a diol, an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid. The wet hardness reduction rate is 15% or less. The wet hardness reduction rate is measured by the following measurement method. Biodegradable polyester resin composition. [Measurement method] The biodegradable polyester resin composition is used to produce a polyester block having a thickness of 2.5 mm. The initial hardness of the polyester block and the wet hardness of the polyester block after being immersed in water at 30 ° C for 24 hours are measured. The wet hardness reduction rate is the value obtained by dividing the difference between the initial hardness and the wet hardness by the initial hardness.

12. The initial hardness is 30 to 45 in Shore D hardness. The wet hardness is 28 to 43 in Shore D hardness. The biodegradable polyester resin composition according to claim 11.

13. The wet hardness reduction rate is 12% or less. The biodegradable polyester resin composition according to claim 11.

14. The silicon element content is 0.1 ppm to 1000 ppm. The biodegradable polyester resin composition according to claim 11.

15. The water contact angle on the surface of the polyester block is 45 ° to 85 °. The biodegradable polyester resin composition according to claim 11.

16. The difference between the wet hardness after immersion in water at 30°C for 1 hour and the wet hardness after immersion in water at 30°C for 24 hours is 10% or less based on the initial hardness. The biodegradable polyester resin composition according to claim 11.

17. The difference between the wet hardness after immersion in water at 30°C for 24 hours and the wet hardness after immersion in water at 70°C for 24 hours is 10% or less based on the initial hardness. The biodegradable polyester resin composition according to claim 11.

18. It includes a polyester resin containing a diol, an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid, The weight swelling ratio is 4% to 20%, The weight swelling ratio is measured by the following measurement method, Biodegradable molded article. [Measurement method] The molded article is manufactured into a sample having a thickness of 300 μm, the initial weight of the sample and the weight after the sample is immersed in ethanol at room temperature for 2 hours are measured, and the weight swelling ratio is the value obtained by dividing the difference between the weight after immersion and the initial weight by the initial weight.

19. The wet hardness reduction rate is 15% or less, The wet hardness reduction rate is measured by the following measurement method, The biodegradable molded article according to claim 18. [Measurement method] The biodegradable molded article is processed to produce a block having a thickness of 2.5 mm, the initial hardness of the block and the wet hardness after the block is immersed in water at 30°C for 24 hours are measured, and the wet hardness reduction rate is the value obtained by dividing the difference between the initial hardness and the wet hardness by the initial hardness.

20. It contains iron element and silicon element, The mass ratio of the iron element to the silicon element is 0.1 to 0.7, The biodegradable molded article according to claim 19.

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