Biodegradable molded article and biodegradable polyester resin composition

Abstract

The example includes a polyester resin containing a diol, an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid, and when irradiated continuously with ultraviolet rays from a UVA340 ultraviolet lamp at a strength of 0.75 W / m 2 ², the tensile strength reduction rate from the initial stage to 1 day of the ultraviolet irradiation is 5% to 40%, and it is intended to provide a biodegradable molded article.

Description

Technical Field

[0001] The examples relate to biodegradable molded articles, biodegradable polyester resin compositions, and biodegradable polyester films.

Background Art

[0002] In recent years, as the concern about environmental problems has increased, solutions to the disposal 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 discharged during incineration, and it has the disadvantage that it takes hundreds of years depending on the type to be completely decomposed naturally.

[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 molded article, a polyester resin composition, and a polyester film containing the same, which have high biodegradability while being resistant to ultraviolet rays and have improved mechanical properties.

Means for Solving the Problems

[0006] The biodegradable molded article according to the example contains a polyester resin containing a diol, an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid. When irradiated with ultraviolet rays from a UVA340 ultraviolet lamp at a strength of 0.75 W / m 2 , the tensile strength reduction rate from the initial stage to 1 day of the ultraviolet irradiation may be 5% to 40% based on a thickness of 300 μm.

[0007] The biodegradable molded article according to one example may contain nanocellulose containing a metal, having an average diameter of 0.5 nm to 10 nm and an average length of 20 nm to 300 nm.

[0008] The biodegradable molded article according to one example may contain a light stabilizer having a weight average molecular weight of 1800 g / mol to 5000 g / mol.

[0009] The biodegradable polyester resin composition according to the example contains a polyester resin containing a diol, an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid. When continuously irradiated with ultraviolet rays from a UVA340 ultraviolet lamp at a strength of 0.75 W / m 2 , the tensile strength reduction rate from the initial stage to 1 day of the ultraviolet irradiation is 5% to 40%, and the tensile strength reduction rate is measured by the following method.

[0010] [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 tensile strength reduction rate is a value obtained by dividing the difference between the initial tensile strength of the polyester sheet and the tensile strength of the polyester sheet after ultraviolet irradiation by the initial tensile strength.

[0011] In the biodegradable polyester resin composition according to one example, the tensile strength reduction rate from the initial stage to 3 days of the ultraviolet irradiation may be 40% to 65%.

[0012] In the biodegradable polyester resin composition according to an embodiment, the tensile strength reduction rate from the initial stage to 6 days of the ultraviolet irradiation may be 67% or more.

[0013] In the biodegradable polyester resin composition according to an embodiment, when the ultraviolet ray is irradiated at a strength of 0.35 W / m 2 ², the tensile strength reduction rate from the initial stage to 1 day of the ultraviolet irradiation may be 1% to 20%.

[0014] In the biodegradable polyester resin composition according to an embodiment, when the ultraviolet ray is irradiated at a strength of 0.35 W / m 2 ², the tensile strength reduction rate from the initial stage to 9 days of the ultraviolet irradiation may be 65% or more.

[0015] In the biodegradable polyester resin composition according to an embodiment, the initial tensile strength may be 40 MPa to 60 MPa, and the tensile strength after 7 days may be 1 MPa to 15 MPa.

[0016] In the biodegradable polyester resin composition according to an embodiment, the elongation at break reduction rate from the initial stage to 1 day of the ultraviolet irradiation may be 5% to 40%, and the elongation at break reduction rate from the initial stage to 7 days of the ultraviolet irradiation may be 80% or more.

[0017] In the biodegradable polyester resin composition according to an embodiment, when the ultraviolet ray is irradiated at a strength of 0.35 W / m 2 ², the elongation at break reduction rate from the initial stage to 1 day of the ultraviolet irradiation may be 1% to 20%, and the elongation at break reduction rate from the initial stage to 9 days of the ultraviolet irradiation may be 80% or more.

[0018] A biodegradable polyester film according to an embodiment contains a polyester resin containing a diol, an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid, and ultraviolet rays from a UVA340 ultraviolet lamp are 0.75 W / m 2When irradiated with the strength of, the tensile strength reduction rate from the initial stage to 1 day of the ultraviolet irradiation may be 5% to 40% based on a thickness of 300 μm.

[0019] The biodegradable polyester resin composition according to one embodiment includes a polyester resin containing a diol, an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid, and a crystallinity regulator, and the crystallinity is 10% to 15%.

[0020] In the biodegradable polyester resin composition according to one embodiment, the crystallinity regulator may contain diisopropyl adipate.

[0021] In the biodegradable polyester resin composition according to one embodiment, the diisopropyl adipate may be contained in an amount of 10 ppm to 10,000 ppm based on the weight of the polyester resin.

[0022] In the biodegradable polyester resin composition according to one embodiment, the tensile strength measured by the following measurement method may be 40 MPa to 60 MPa.

[0023] [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, and the tensile strength of the polyester sheet is measured.

[0024] In the biodegradable polyester resin composition according to one embodiment, the elongation at break measured by the following measurement method may be 800% to 1200%.

[0025] [Measurement method] The elongation at break of the polyester sheet is measured.

[0026] In the biodegradable polyester resin composition according to one embodiment, the Shore D hardness measured by the following measurement method may be 30 to 45.

[0027] [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 block having a thickness of 2.5 mm, and the Shore D hardness of the polyester block is measured.

[0028] In the biodegradable polyester resin composition according to one embodiment, the crystallinity regulator may contain tetrahydrofuran.

[0029] In the biodegradable polyester resin composition according to one embodiment, the weight ratio of the diisopropyl adipate and the tetrahydrofuran may be 1:1 to 1:5.

[0030] In the biodegradable polyester resin composition according to one embodiment, the rate of alternation of the polyester resin is 0.37 to 0.59, and the rate of alternation may be the ratio of the diol that binds between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid among the diols. [Advantages of the Invention]

[0031] The biodegradable molded article, biodegradable polyester resin composition, and biodegradable polyester film according to the embodiment have a low tensile strength reduction rate from the initial stage to 1 day of ultraviolet rays. That is, the biodegradable molded article, biodegradable polyester resin composition, and biodegradable polyester film according to the embodiment have a low initial tensile strength reduction rate when exposed to ultraviolet rays. As a result, the biodegradable molded article and biodegradable polyester film according to the embodiment have a low reduction in tensile strength due to ultraviolet exposure within the normal usage period.

[0032] As a result, the biodegradable molded article and biodegradable film according to the examples can appropriately maintain mechanical strength within the normal usage period.

[0033] In addition, the biodegradable molded article, biodegradable polyester resin composition, and film according to the examples may have a high tensile strength reduction rate when exposed to ultraviolet rays for a long time. For example, the biodegradable molded article, polyester resin composition, and biodegradable film according to the examples may have a tensile strength reduction rate of 67% or more 6 days after the initial stage of ultraviolet irradiation.

[0034] As a result, the biodegradable molded article, biodegradable polyester resin composition, and biodegradable film according to the examples can be easily decomposed when exposed to sunlight for a long time after being discarded. The biodegradable molded article, biodegradable polyester resin composition, and biodegradable film according to the examples can be easily decomposed not only by biodegradation but also by decomposition by sunlight. In addition, the molded article produced from the biodegradable polyester resin composition according to the examples can be decomposed more efficiently in a natural state because decomposition by sunlight promotes biodegradation. The biodegradable molded article and biodegradable film according to the examples can also be easily decomposed by ultraviolet rays or the like when discarded into the sea.

[0035] Therefore, the biodegradable molded article, biodegradable polyester resin composition, and biodegradable polyester film according to the examples can reduce the burden on the global environment, particularly reduce the pollution of the marine ecosystem.

[0036] In addition, the biodegradable polyester resin composition according to the examples may contain a crystallinity regulator. As a result, the biodegradable polyester resin composition according to the examples may have an appropriate crystallinity.

[0037] In particular, during the process of manufacturing the biodegradable polyester resin composition according to the examples, a chain extension reaction and / or a post-treatment reaction can be carried out. At this time, the crystallinity regulator can be appropriately applied, and the biodegradable polyester resin composition according to the examples may have an appropriate crystallinity. For example, when the chain extension reaction and / or the post-treatment reaction is carried out, the crystallinity may increase. At this time, the crystallinity regulator can appropriately lower the crystallinity.

[0038] Thereby, the molded article produced from the biodegradable polyester resin composition according to the examples can appropriately maintain its mechanical strength within the normal service life.

[0039] For example, the biodegradable polyester resin composition according to the examples may have an appropriate tensile strength, an appropriate elongation at break, and / or an appropriate hardness.

[0040] Also, even if the biodegradable polyester resin composition according to the examples has a high content of aliphatic carboxylic acid, it can have improved mechanical properties. Thereby, the biodegradable polyester resin composition according to the examples may simultaneously have improved mechanical properties and appropriate biodegradability.

[0041] The molded article produced from the biodegradable polyester resin composition according to the examples can be efficiently decomposed at the time of disposal while maintaining the required mechanical properties during the actual service life.

Brief Description of the Drawings

[0042]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0043] Hereinafter, the invention will be described in detail with reference to embodiments. The embodiments 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.

[0044] 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.

[0045] 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” unless otherwise specified.

[0046] 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 only used for the purpose of distinguishing one component from another.

[0047] The biodegradable polyester resin composition according to the embodiment includes a biodegradable polyester resin. The biodegradable polyester resin composition according to the embodiment may include the biodegradable polyester resin alone or together with other resins or additives.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] The diol may contain 1,4-butanediol or a derivative thereof.

[0054] 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.

[0055] 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.

[0056] The aromatic dicarboxylic acid may contain terephthalic acid, dimethyl terephthalate, or derivatives thereof.

[0057] 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.

[0058] The aliphatic dicarboxylic acid may be at least one selected from the group consisting of adipic acid, succinic acid, sebacic acid, or derivatives thereof.

[0059] The aliphatic dicarboxylic acid may contain adipic acid or a derivative thereof.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] The biodegradable polyester resin may contain aromatic dicarboxylic acid residues derived from terephthalic acid or dimethyl terephthalate in a content 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 a content 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 a content of about 40 mol% to about 60 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 a content of about 43 mol% to about 53 mol% based on the total dicarboxylic acid.

[0064] The biodegradable polyester resin may contain aliphatic dicarboxylic acid residues derived from adipic acid in a content 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 a content 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 a content of about 40 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 a content of about 47 mol% to about 57 mol% based on the total dicarboxylic acid.

[0065] Also, the biodegradable polyester resin may include 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.

[0066] 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 the aliphatic dicarboxylic acid binds.

[0067] 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 the aromatic dicarboxylic acid binds.

[0068] 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. Further, 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 0.8 to 1. The number of the first blocks may be even smaller than the number of the second blocks.

[0069] 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.

[0070] 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 rate of alternation described below. That is, as the molar ratio of the aromatic dicarboxylic acid increases, as the molecular weight of the biodegradable polyester resin increases, and as the degree of alternation described below increases, the number of the first blocks may increase.

[0071] 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.

[0072] The number of the second blocks may vary depending on the content of the aliphatic dicarboxylic acid, the molecular weight of the biodegradable polyester resin, and the degree of alternation described later.

[0073] 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.

[0074] The first block may be represented by the following Chemical Formula 1.

[0075]

Chemical Formula

[0076] 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.

[0077] The R1 is a substituted or unsubstituted phenylene group, and the R2 may be a butylene group.

[0078] The second block may be represented by Chemical Formula 2 below.

[0079]

Chemical Formula

[0080] Here, the R3 and the R4 are each independently a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, and the n may be 1 to 20.

[0081] The R3 and the R4 may be a butylene group.

[0082] 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.

[0083]

Chemical Formula

[0084] Here, the R1 is a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, the R2 is a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, and the m may be 1 to 20. Further, the R3 and the R4 are each independently a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, and the n may be 1 to 20.

[0085] The diol residue may contain a residue of 1,4 - butanediol or its derivative, the aromatic dicarboxylic acid residue may contain a residue of terephthalic acid or its derivative, and the aliphatic dicarboxylic acid residue may contain a residue of adipic acid or its derivative.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] The first block may be represented by Chemical Formula 4 below, and the second block may be represented by Chemical Formula 5 below.

[0092]

Chemical Formula

[0093] Here, m may be 1 to 20.

[0094]

Chemical Formula

[0095] Here, the said n may be 1 to 20.

[0096] The biodegradable polyester resin may be the one represented by Chemical Formula 6 below.

[0097] [Chemical Formula]

[0098] Here, the said m is 1 to 20, and the said n may be 1 to 20.

[0099] 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 excellent in biodegradability and hydrolysis resistance and having improved physical properties.

[0100] 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 physical properties and appropriate UV resistance characteristics.

[0101] Since the first block and the second block have the above characteristics, the mechanical physical properties of the biodegradable polyester resin composition according to the examples can be improved.

[0102] 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 characteristics.

[0103] 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.

[0104] 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.

[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 biodegradation rate and improved UV resistance.

[0106] The biodegradable polyester resin may include the following bonding structures 1 to 3.

[0107] [Bonding structure 1] -Aromatic dicarboxylic acid - diol - aliphatic dicarboxylic acid - [Bonding structure 2] -Aromatic dicarboxylic acid - diol - aromatic dicarboxylic acid - [Bonding structure 3] -Aliphatic dicarboxylic acid - diol - aliphatic dicarboxylic acid -

[0108] The diol contained in the above bonding structure 1 binds to the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid. The diol contained in the above bonding structure 1 may directly form an ester bond with the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid.

[0109] Also, the diol contained in the above bonding structure 2 binds to the aromatic dicarboxylic acid and the aromatic dicarboxylic acid between the aromatic dicarboxylic acid and the aromatic dicarboxylic acid. The diol contained in the above bonding structure 2 may directly form an ester bond with the aromatic dicarboxylic acid and the aromatic dicarboxylic acid between the aromatic dicarboxylic acid and the aromatic dicarboxylic acid.

[0110] In addition, the diol contained in the above bonding structure 3 binds to the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid between the aliphatic dicarboxylic acids. The diol contained in the above bonding structure 3 may be directly esterified and bonded to the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid between the aliphatic dicarboxylic acids.

[0111] In the biodegradable polyester resin, the above bonding structure 1 may be represented by the following Chemical Formula 7.

[0112]

Chemical Formula

[0113] 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 R3 is a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms.

[0114] In the biodegradable polyester resin, the above bonding structure 2 may be represented by the following Chemical Formula 8.

[0115]

Chemical Formula

[0116] Similarly, R1 is a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, and R2 is a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms.

[0117] In the biodegradable polyester resin, the above bonding structure 3 may be represented by the following Chemical Formula 9.

[0118]

Chemical Formula

[0119] R2 is a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, and R3 is a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms.

[0120] Further, the above bonding structure 1 may be represented by Chemical Formula 10 below.

[0121]

Chemical Formula

[0122] Further, the above bonding structure 2 may be represented by Chemical Formula 11 below.

[0123]

Chemical Formula

[0124] Further, the above bonding structure 3 may be represented by Chemical Formula 12 below.

[0125]

Chemical Formula

[0126] The biodegradable polyester resin has an alternating ratio.

[0127] The alternating ratio is the ratio of the diol that binds between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid among the diols. That is, the alternating ratio may be the ratio of the diol contained in the above bonding structure 1 among the diols. The alternating ratio may be a value obtained by dividing the number of moles of the diol contained in the above bonding structure 1 by the sum of the number of moles of the diol contained in the above bonding structure 1, the number of moles of the diol contained in the above bonding structure 2, and the number of moles of the diol contained in the above bonding structure 3.

[0128] That is, the crosslinking ratio may be the ratio of the diols in which two of the total diols are bonded between the dicarboxylic acids.

[0129] The above crosslinking ratio can be calculated by the following formula 1.

[0130] [Formula 1] JPEG2025522289000014.jpg20128

[0131] Here, the DM1 is the molar ratio of the diols contained in the above bonding structure 1, the DM2 is the molar ratio of the diols contained in the above bonding structure 2, and the DM3 is the molar ratio of the diols contained in the above bonding structure 3.

[0132] In the biodegradable polyester resin, the crosslinking ratio may be about 0.3 to about 0.7. In the biodegradable polyester resin, the crosslinking ratio may be about 0.37 to about 0.59. In the biodegradable polyester resin, the crosslinking ratio may be about 0.4 to about 0.56. In the biodegradable polyester resin, the crosslinking ratio may be about 0.45 to about 0.53.

[0133] Also, the biodegradable polyester resin contains a ratio of hard segments.

[0134] The ratio of the hard segments is the ratio of the diols in which the aromatic dicarboxylic acid and the aromatic dicarboxylic acid are bonded among the diols.

[0135] The ratio of the hard segments may be the molar ratio of the diols contained in the above bonding structure 2 among the total diols. The ratio of the hard segments may be the value obtained by dividing the number of moles of the diols contained in the above bonding structure 2 by the sum of the number of moles of the diols contained in the above bonding structure 1, the number of moles of the diols contained in the above bonding structure 2, and the number of moles of the diols contained in the above bonding structure 3.

[0136] The ratio of the hard segment may be represented by the following Mathematical Formula 2.

[0137] [Mathematical Formula 2] JPEG2025522289000015.jpg20137

[0138] Here, the DM1 is the molar ratio of the diol contained in the bonding structure 1, the DM2 is the molar ratio of the diol contained in the bonding structure 2, and the DM3 is the molar ratio of the diol contained in the bonding structure 3.

[0139] The ratio of the hard segment may be about 0.15 to about 0.35. The ratio of the hard segment may be about 0.2 to about 0.3. The ratio of the hard segment may be about 0.21 to about 0.29. The ratio of the hard segment may be about 0.22 to about 0.28.

[0140] Further, the biodegradable polyester resin composition contains a soft segment.

[0141] The ratio of the soft segment is the ratio of the diol that binds between the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid among the diols.

[0142] The ratio of the soft segment may be the molar ratio of the diol contained in the bonding structure 3 among all the diols. The ratio of the soft segment may be a value obtained by dividing the number of moles of the diol contained in the bonding structure 3 by the sum of the number of moles of the diol contained in the bonding structure 1, the number of moles of the diol contained in the bonding structure 2, and the number of moles of the diol contained in the bonding structure 3.

[0143] The ratio of the soft segment may be represented by the following Mathematical Formula 3.

[0144] [Mathematical Formula 3] JPEG2025522289000016.jpg20137

[0145] Here, the DM1 is the molar ratio of the diol contained in the bonding structure 1, the DM2 is the molar ratio of the diol contained in the bonding structure 2, and the DM3 is the molar ratio of the diol contained in the bonding structure 3.

[0146] The ratio of the soft segment may be about 0.16 to about 0.36. The ratio of the soft segment may be about 0.21 to about 0.31. The ratio of the soft segment may be about 0.22 to about 0.30. The ratio of the hard segment may be about 0.23 to about 0.29.

[0147] The ratio of the soft segment may be even greater than the ratio of the hard segment.

[0148] The ratio of the hard segment to the soft segment may be about 0.92 to about 0.99. That is, the value obtained by dividing the DM2 by the DM3 may be about 0.92 to about 0.99.

[0149] The ratio of the crosslinking, the ratio of the hard segment, and the ratio of the soft segment can be measured by nuclear magnetic resonance spectroscopy. The biodegradable polyester resin composition according to the examples is dissolved in a solvent such as CDCl3 and analyzed by a nuclear magnetic resonance (NMR) apparatus at room temperature 1 by 1H-NMR and / or 13 13C-NMR analysis.

[0150] When the diol is 1,4-butanediol, the aromatic dicarboxylic acid is terephthalic acid or dimethyl terephthalate, and the aliphatic dicarboxylic acid is adipic acid, the analysis of the biodegradable polyester resin by the nuclear magnetic resonance spectroscopy may include a first peak, a second peak, a third peak, a fourth peak, a fifth peak, a sixth peak, a seventh peak, an eighth peak, a ninth peak, a tenth peak, and an eleventh peak.

[0151] For example, when the diol is 1,4 - butanediol, the aromatic dicarboxylic acid is terephthalic acid or dimethyl terephthalate, and the aliphatic dicarboxylic acid is adipic acid, the analysis of the biodegradable polyester resin by the nuclear magnetic resonance spectroscopy may include peaks derived from the diol of the above - mentioned bonding structure 1, peaks derived from the diol of the above - mentioned bonding structure 2, and peaks derived from the above - mentioned bonding structure 3 at about 3.5 ppm to about 4.6 ppm.

[0152] The first peak, the second peak, the third peak, and the fourth peak may be defined in the order from a higher ppm to a lower ppm in the range of about 3.5 ppm to about 4.6 ppm. Also, the first peak, the second peak, the third peak, and the fourth peak may be defined in the order from a higher ppm to a lower ppm in the range of about - 3.4 ppm to about - 4.3 ppm based on the ppm of the ninth peak. Here, at this time, the first peak may be derived from the diol contained in the second bonding unit, the second peak and the third peak may be derived from the diol contained in the first bonding unit, and the fourth peak may be derived from the diol contained in the third bonding unit.

[0153] The direction of - ppm may be the upfield direction or the shielded direction. For example, - 3.4 ppm may mean the position at 3.4 ppm in the upfield direction. For example, - 3.4 ppm may mean the position at 3.4 ppm in the shielded direction.

[0154] Also, the analysis of the biodegradable polyester resin by the nuclear magnetic resonance spectroscopy may include peaks derived from the diol of the above - mentioned bonding structure 1, peaks derived from the diol of the above - mentioned bonding structure 2, and peaks derived from the above - mentioned bonding structure 3 at about 1.0 ppm to about 2.5 ppm.

[0155] The 10th peak, the 5th peak, the 6th peak, the 7th peak, the 8th peak, and the 11th peak may be defined in the range of about 1.0 ppm to about 2.5 ppm in descending order of ppm from high to low. The 5th peak, the 6th peak, the 7th peak, the 8th peak, and the 11th peak may be defined in the range of about -6.0 ppm to about -6.7 ppm with reference to the ppm of the 9th peak in descending order of ppm from high to low. At this time, the 5th peak may be derived from the diol contained in the second linking unit, the 6th peak and the 7th peak may be derived from the diol contained in the first linking unit, and the 8th peak may be derived from the diol contained in the third linking unit.

[0156] Also, the 9th peak may be formed in the range of about 7.5 ppm to about 8.5 ppm. The 9th peak may be derived from the aromatic dicarboxylic acid. The 9th peak may be derived from the aromatic ring contained in the aromatic dicarboxylic acid. The 9th peak may be derived from the aromatic ring contained in the terephthalic acid or dimethyl terephthalate.

[0157] The 10th peak and the 11th peak may be derived from the aliphatic dicarboxylic acid. The 10th peak and the 11th peak may be derived from the adipic acid.

[0158] The first peak may be located at about -3.6 ppm to about -3.68 ppm based on the ppm of the ninth peak. The second peak may be located at about -3.69 ppm to about -3.75 ppm based on the ppm of the ninth peak. The third peak may be located at about -3.9 ppm to about -3.97 ppm based on the ppm of the ninth peak. The fourth peak may be located at about -3.98 ppm to about -4.1 ppm based on the ppm of the ninth peak. The fifth peak may be located at about -6.0 ppm to about -6.19 ppm based on the ppm of the ninth peak. The sixth peak may be located at about -6.2 ppm to about -6.26 ppm based on the ppm of the ninth peak. The seventh peak may be located at about -6.27 ppm to about -6.34 ppm based on the ppm of the ninth peak. The eighth peak may be located at about -6.35 ppm to about -6.42 ppm based on the ppm of the ninth peak. The tenth peak may be located at about -5.6 ppm to about -5.8 ppm based on the ppm of the ninth peak. The eleventh peak may be located at about -6.421 ppm to about -6.5 ppm based on the ppm of the ninth peak. The position based on the ppm of the ninth peak may be the position of each peak when the position of the ninth peak is 0 ppm.

[0159] Also, the areas of the first peak, the second peak, the third peak, the fourth peak, the fifth peak, the sixth peak, the seventh peak, the eighth peak, the tenth peak, and the eleventh peak can be normalized based on the area of the ninth peak. That is, when the area of the ninth peak is 1, the areas of the first peak, the second peak, the third peak, the fourth peak, the fifth peak, the sixth peak, the seventh peak, the eighth peak, the tenth peak, and the eleventh peak can be determined relatively.

[0160] The ratio of the interaction can be derived by the following formula 4 or formula 5.

[0161] [Formula 4] JPEG2025522289000017.jpg19128

[0162] Here, the PA1 is the area of the first peak, the PA2 is the area of the second peak, the PA3 is the area of the third peak, and the PA4 is the area of the fourth peak.

[0163] [Formula 5] JPEG2025522289000018.jpg19128

[0164] Here, the PA5 is the area of the fifth peak, the PA6 is the area of the sixth peak, the PA7 is the area of the seventh peak, and the PA8 is the area of the eighth peak.

[0165] The ratio of the hard segment can be derived by the following formula 6 or the following formula 7.

[0166] [Formula 6] JPEG2025522289000019.jpg20145

[0167] Here, the PA1 is the area of the first peak, the PA2 is the area of the second peak, the PA3 is the area of the third peak, and the PA4 is the area of the fourth peak.

[0168] [Formula 7] JPEG2025522289000020.jpg20145

[0169] Here, the PA5 is the area of the fifth peak, the PA6 is the area of the sixth peak, the PA7 is the area of the seventh peak, and the PA8 is the area of the eighth peak.

[0170] The ratio of the soft segment can be derived by the following formula 8 or formula 9.

[0171] [Formula 8] JPEG2025522289000021.jpg20145

[0172] Here, the PA1 is the area of the first peak, the PA2 is the area of the second peak, the PA3 is the area of the third peak, and the PA4 is the area of the fourth peak.

[0173] [Formula 9] JPEG2025522289000022.jpg20145

[0174] Here, the PA5 is the area of the fifth peak, the PA6 is the area of the sixth peak, the PA7 is the area of the seventh peak, and the PA8 is the area of the eighth peak.

[0175] The area of the first peak may be about 0.35 to about 0.6. The area of the first peak may be about 0.4 to about 0.55. The area of the first peak may be about 0.43 to about 0.5. The area of the first peak may be about 0.43 to about 0.52. The area of the first peak may be about 0.45 to about 0.49.

[0176] The area of the second peak may be about 0.37 to about 0.57. The area of the second peak may be about 0.41 to about 0.54. The area of the second peak may be about 0.45 to about 0.53. The area of the second peak may be about 0.45 to about 0.55. The area of the second peak may be about 0.47 to about 0.53.

[0177] The area of the third peak may be from about 0.37 to about 0.57. The area of the third peak may be from about 0.41 to about 0.54. The area of the third peak may be from about 0.45 to about 0.53. The area of the third peak may be from about 0.45 to about 0.55. The area of the third peak may be from about 0.47 to about 0.53.

[0178] The area of the fourth peak may be from about 0.4 to 0.7. The area of the fourth peak may be from about 0.45 to about 0.65. The area of the fourth peak may be from about 0.48 to about 0.6. The area of the fourth peak may be from about 0.48 to 0.60. The area of the fourth peak may be from about 0.50 to about 0.58.

[0179] The area of the fifth peak may be from about 0.35 to about 0.6. The area of the fifth peak may be from about 0.4 to about 0.55. The area of the fifth peak may be from 0.43 to about 0.53. The area of the fifth peak may be from about 0.43 to about 0.52. The area of the fifth peak may be from about 0.45 to about 0.49.

[0180] The area of the sixth peak may be from about 0.35 to about 0.6. The area of the sixth peak may be from about 0.4 to about 0.55. The area of the sixth peak may be from 0.43 to about 0.5. The area of the sixth peak may be from about 0.45 to about 0.55. The area of the sixth peak may be from about 0.47 to about 0.53.

[0181] The area of the seventh peak may be from about 0.41 to about 0.71. The area of the seventh peak may be from about 0.45 to about 0.65. The area of the seventh peak may be from about 0.48 to about 0.6. The area of the seventh peak may be from about 0.45 to about 0.55. The area of the seventh peak may be from about 0.47 to about 0.53.

[0182] The area of the eighth peak may be from about 0.4 to about 0.7. The area of the eighth peak may be from about 0.45 to about 0.65. The area of the eighth peak may be from about 0.48 to about 0.6. The area of the eighth peak may be from about 0.48 to 0.60. The area of the eighth peak may be from about 0.50 to about 0.58.

[0183] The area of the tenth peak may be from about 0.7 to about 2.5. The area of the tenth peak may be from 0.75 to about 2. The area of the tenth peak may be from 0.8 to about 1.5. The area of the tenth peak may be from about 1.0 to about 1.15. The area of the tenth peak may be from about 1.02 to about 1.13.

[0184] The area of the eleventh peak may be from about 0.7 to about 3.5. The area of the eleventh peak may be from about 0.7 to about 3. The area of the eleventh peak may be from 0.8 to about 2.5. The area of the eleventh peak may be from about 1.0 to about 1.15. The area of the eleventh peak may be from about 1.02 to about 1.13.

[0185] Also, the sum of the areas of the first peak, the second peak, the third peak, and the fourth peak may be from about 1.49 to about 2.44. The sum of the areas of the first peak, the second peak, the third peak, and the fourth peak may be from about 1.81 to about 2.16. The sum of the areas of the first peak, the second peak, the third peak, and the fourth peak may be from about 1.9 to about 2.2. The sum of the areas of the first peak, the second peak, the third peak, and the fourth peak may be from about 1.95 to about 2.1. Here, the sum of the areas of the first peak, the second peak, the third peak, and the fourth peak may mean the sum of the number of total ester bonds based on the number of terephthalic acid molecules.

[0186] The sum of the area of the second peak and the area of the third peak may be from about 0.95 to about 1.10. The sum of the area of the second peak and the area of the third peak may be from about 0.98 to about 1.07. Here, the sum of the area of the first peak and the area of the third peak may represent the degree to which the molecular bonds of the biodegradable polyester resin extend.

[0187] The ratio of the area of the fourth peak to the area of the first peak (area of the fourth peak / area of the first peak) may be from about 1.1 to about 1.3. The ratio of the area of the fourth peak to the area of the first peak may be from about 0.67 to about 2.00. The ratio of the area of the fourth peak to the area of the first peak may be from about 0.96 to about 1.40. The ratio of the area of the fourth peak to the area of the first peak may be from about 1.15 to about 1.25. The ratio of the area of the fourth peak to the area of the first peak may represent the ratio of the soft segment to the hard segment within the molecular structure of the biodegradable polyester resin. That is, the higher the ratio of the area of the fourth peak to the area of the first peak, the more flexible the biodegradable polyester resin may be.

[0188] The ratio of the area of the fourth peak to the area of the third peak (area of the fourth peak / area of the third peak) may be from about 0.7 to about 1.89. The ratio of the area of the fourth peak to the area of the third peak may be from about 0.91 to about 1.33. The ratio of the area of the fourth peak to the area of the third peak may be from about 1.0 to about 1.2. The ratio of the area of the fourth peak to the area of the third peak may be from about 1.01 to about 1.1.

[0189] The ratio of the area of the first peak to the area of the second peak (area of the first peak / area of the second peak) may be from about 0.61 to about 1.62. The ratio of the area of the first peak to the area of the second peak may be from about 0.81 to about 1.11. The ratio of the area of the first peak to the area of the second peak may be from about 0.85 to about 0.95. The ratio of the area of the first peak to the area of the second peak may be from about 0.86 to about 0.94.

[0190] Also, the ratio of the area of the fifth peak to the area of the first peak (area of the fifth peak / area of the first peak) may be from about 0.61 to about 1.71. The ratio of the area of the fifth peak to the area of the first peak may be from about 0.96 to about 1.40. The ratio of the area of the fifth peak to the area of the first peak may be from about 0.8 to about 1.2. The ratio of the area of the fifth peak to the area of the first peak may be from about 0.9 to about 1.1.

[0191] Also, the ratio of the area of the sixth peak to the area of the second peak (area of the sixth peak / area of the second peak) may be from about 0.58 to about 1.71. The ratio of the area of the sixth peak to the area of the first peak may be from about 0.86 to about 1.16. The ratio of the area of the sixth peak to the area of the first peak may be from about 0.8 to about 1.2. The ratio of the area of the sixth peak to the area of the first peak may be from about 0.9 to about 1.1.

[0192] Also, the ratio of the area of the seventh peak to the area of the third peak (area of the seventh peak / area of the third peak) may be from about 0.72 to about 1.92. The ratio of the area of the seventh peak to the area of the third peak may be from about 0.91 to about 1.33. The ratio of the area of the seventh peak to the area of the third peak may be from about 0.8 to about 1.2. The ratio of the area of the seventh peak to the area of the third peak may be from about 0.9 to about 1.1.

[0193] Also, the ratio of the area of the eighth peak to the area of the fourth peak (area of the eighth peak / area of the fourth peak) may be from about 0.59 to about 1.75. The ratio of the area of the eighth peak to the area of the fourth peak may be from about 0.80 to about 1.25. The ratio of the area of the eighth peak to the area of the fourth peak may be from about 0.8 to about 1.2. The ratio of the area of the eighth peak to the area of the fourth peak may be from about 0.9 to about 1.1.

[0194] Since the biodegradable polyester resin has the molecular structure as described above, the biodegradable polyester resin composition according to the examples can provide a biodegradable polyester sheet, film or molded article that is excellent in biodegradability and hydrolysis resistance and has improved physical properties, which may be more advantageous.

[0195] Also, since the biodegradable polyester resin has the molecular structure as described above, the biodegradable polyester resin composition according to the examples may have appropriate mechanical properties and appropriate UV resistance.

[0196] Since the biodegradable polyester resin has the molecular structure as described above, the mechanical properties of the biodegradable polyester resin composition according to the examples can be improved.

[0197] Since the biodegradable polyester resin has the molecular structure as described above, the biodegradable polyester resin composition according to the examples may have appropriate UV resistance.

[0198] Since the first block and the second block have the characteristics as described above, the biodegradable polyester resin composition according to the examples may have an appropriate biodegradation rate.

[0199] Since the biodegradable polyester resin has the molecular structure as described above, the biodegradable polyester resin composition according to the examples may have an appropriate hydrolysis rate.

[0200] The biodegradable polyester resin may further contain a branching agent. The branching agent may contain an alcohol having a valency of 3 or more and / or a carboxylic acid having a valency of 3 or more. 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 a part of the molecular structure in the biodegradable polyester resin.

[0201] At least one of the alcohols having a valency of 3 or more may be selected from the group consisting of glycerol, pentaerythritol, or trimethylolpropane.

[0202] At least one of the carboxylic acids having a valency of 3 or more may be 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.

[0203] 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.

[0204] Since the biodegradable polyester resin contains the branching agent within the above range, the biodegradable polyester resin composition according to the examples may have improved UV resistance characteristics, appropriate mechanical properties, and appropriate biodegradability.

[0205] The biodegradable polyester resin composition according to the examples may contain the biodegradable resin at 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 at 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 at 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 at 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 at 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 at 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 at 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.

[0206] 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.

[0207] 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.

[0208] 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.

[0209] 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.

[0210] The nanocellulose may be represented by Chemical Formula 13 below.

[0211] [Chemical]

[0212] 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.

[0213] The nanofibrillated cellulose may have a specific surface area of about 200 m 2 / g to about 600 m 2 / g. The nanofibrillated cellulose may have a specific surface area of about 250 m 2 / g to about 500 m 2 / g.

[0214] The weight average molecular weight of the nanofibrillated cellulose 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.

[0215] 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%.

[0216] The average diameter of the nanofibrillated cellulose may be from about 0.5 nm to about 10 nm. The average diameter of the nanofibrillated cellulose may be from about 1 nm to about 8 nm. The average diameter of the nanofibrillated cellulose may be from about 1.5 nm to about 7 nm.

[0217] The average length of the nanofibrillated cellulose may be from about 20 nm to about 300 nm. The average length of the nanofibrillated cellulose may be from about 30 nm to about 180 nm. The average length of the nanofibrillated cellulose may be from about 35 nm to about 150 nm.

[0218] By satisfying the diameter and length of the nanocellulose within 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.

[0219] The diameter and length of the nanocellulose can be measured by atomic force microscopy in a state of being dispersed in water.

[0220] The sulfur content of the nanocellulose may be about 0.1 wt% to about 1.2 wt% based on the whole nanocrystalline cellulose. The sulfur content of the nanocrystalline cellulose may be about 0.2 wt% to about 1.1 wt% based on the whole nanocellulose.

[0221] The pH of the nanocellulose may be 5 to 8. The pH of the nanocellulose may be 6 to 8.

[0222] 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.

[0223] The nanocellulose may be included in the biodegradable polyester resin composition according to the examples at a content of about 0.01 part 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 at a content of about 0.03 part 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 at a content of about 0.04 part 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 at a content of about 0.05 part by weight to about 1 part by weight based on 100 parts by weight of the biodegradable polyester resin.

[0224] Since the nanocellulose has the above-mentioned characteristics, it can be uniformly dispersed in the biodegradable polyester resin composition according to the examples.

[0225] Since the nanocellulose has the above-mentioned characteristics, the mechanical properties of the biodegradable polyester resin composition according to the examples can be improved.

[0226] In addition, the nanocellulose functions as a crystallization nucleating agent and can improve the crystallization rate of the biodegradable polyester resin composition according to the examples. As a result, the nanocellulose can increase the crystallization temperature of the biodegradable polyester resin composition according to the examples.

[0227] Since the nanocellulose has the above-mentioned characteristics, the biodegradable polyester resin composition according to the examples may have appropriate UV resistance characteristics.

[0228] Since the nanocellulose has the above-mentioned characteristics, the biodegradable polyester resin composition according to the examples may have an appropriate biodegradation rate.

[0229] Since the nanocellulose has the above-mentioned characteristics, the biodegradable polyester resin composition according to the examples may have an appropriate hydrolysis rate.

[0230] The biodegradable polyester resin composition according to the examples may further contain a light stabilizer.

[0231] The light stabilizer may be a hindered amine light stabilizer. The light stabilizer may include SUNOVIN 904 of SUNSHOW Co., Ltd.

[0232] The light stabilizer may have a high molecular weight. The weight average molecular weight of the light stabilizer may be from about 1800 g / mol to about 5000 g / mol. The weight average molecular weight of the light stabilizer may be from about 2000 g / mol to about 4000 g / mol.

[0233] The melting point of the light stabilizer may be from about 100°C to about 200°C. The melting point of the light stabilizer may be from about 110°C to about 150°C.

[0234] When thermogravimetric analysis is performed up to a temperature of about 424°C, the volatilization amount of the light stabilizer may be about 1 wt% or less. Also, when thermogravimetric analysis is performed up to a temperature of about 424°C, the carbonization amount of the light stabilizer may be about 0.1 wt% or less.

[0235] The light stabilizer may be included in the biodegradable polyester resin composition according to the examples in an amount of about 0.01 parts by weight to about 5 parts by weight based on 100 parts by weight of the biodegradable polyester resin. The light stabilizer may be included in the biodegradable polyester resin composition according to the examples in an amount of about 0.05 parts by weight to about 1 part by weight based on 100 parts by weight of the biodegradable polyester resin. The light stabilizer may be included in the biodegradable polyester resin composition according to the examples in an amount of about 0.1 parts by weight to about 0.5 parts by weight based on 100 parts by weight of the biodegradable polyester resin.

[0236] Since the light stabilizer has the above characteristics, it can be uniformly dispersed in the biodegradable polyester resin composition according to the examples.

[0237] Since the light stabilizer has the above characteristics, the mechanical properties of the biodegradable polyester resin composition according to the examples can be improved.

[0238] Since the light stabilizer has the above characteristics, the biodegradable polyester resin composition according to the examples may have appropriate UV resistance characteristics.

[0239] Since the light stabilizer has the above characteristics, the biodegradable polyester resin composition according to the examples may have an appropriate biodegradation rate.

[0240] Since the light stabilizer has the above characteristics, the biodegradable polyester resin composition according to the examples may have an appropriate hydrolysis rate.

[0241] The biodegradable polyester resin composition according to the examples may contain a metal salt.

[0242] 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.

[0243] At least one or more of the metal salts may be selected from the group consisting of nitrates, sulfates, hydrochlorides, carboxylates, etc. At least one or more 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 or more 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.

[0244] 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).

[0245] Alternatively, the metal salt may be selected from the group consisting of acetate, nitrate, nitride, sulfide, sulfate, sulfoxide, hydroxide, hydrate, chloride, chlorinate, and bromide.

[0246] 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.

[0247] The biodegradable polyester resin composition according to the examples may contain an elongation improver. Examples of the elongation improver include oils such as paraffin oil, naphthene oil, or aromatic oil, or those having adipates such as dibutyl adipate, diethylhexyl adipate, dioctyl adipate, or diisopropyl adipate.

[0248] The elongation improver may be contained in the biodegradable polyester resin composition according to the examples in a content 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 examples in a content of about 0.01 part by weight to about 1 part by weight based on 100 parts by weight of the biodegradable polyester resin.

[0249] Since the elongation rate improver has the above characteristics, the mechanical properties of the biodegradable polyester resin composition according to the examples can be improved.

[0250] Since the elongation rate improver has the above characteristics, the biodegradable polyester resin composition according to the examples may have appropriate UV resistance characteristics.

[0251] Since the elongation rate improver has the above characteristics, the biodegradable polyester resin composition according to the examples may have an appropriate biodegradation rate.

[0252] Since the elongation rate improver has the above characteristics, the biodegradable polyester resin composition according to the examples may have an appropriate hydrolysis rate.

[0253] The biodegradable polyester resin composition according to the examples contains a crystallization regulator. The biodegradable polyester resin composition according to the examples can appropriately adjust the crystallization characteristics by appropriately using the crystallization regulator.

[0254] In addition, the elongation rate improver can be used as the crystallization regulator. The biodegradable polyester resin composition according to the examples can appropriately adjust the crystallization characteristics by appropriately using the elongation rate improver.

[0255] The crystallization regulator may contain diisopropyl adipate. Further, the crystallization regulator may contain the diisopropyl adipate and tetrahydrofuran. Further, the crystallization regulator may contain the diisopropyl adipate, the tetrahydrofuran, and cyclopentanone.

[0256] The crystallization regulator may be included in the biodegradable polyester resin composition according to the examples in an amount of about 10 ppm to about 20,000 ppm based on the total weight of the biodegradable polyester resin composition according to the examples. The crystallization regulator may be included in the biodegradable polyester resin composition according to the examples in an amount of about 10 ppm to about 10,000 ppm based on the total weight of the biodegradable polyester resin composition according to the examples. The crystallization regulator may be included in the biodegradable polyester resin composition according to the examples in an amount of about 100 ppm to about 5,000 ppm based on the total weight of the biodegradable polyester resin composition according to the examples. The crystallization regulator may be included in the biodegradable polyester resin composition according to the examples in an amount of about 50 ppm to about 5,000 ppm based on the total weight of the biodegradable polyester resin composition according to the examples.

[0257] Also, the weight ratio of the diisopropyl adipate and the tetrahydrofuran may be about 1:1 to about 1:5. The weight ratio of the diisopropyl adipate and the tetrahydrofuran may be about 1:2 to about 1:4. The weight ratio of the diisopropyl adipate and the tetrahydrofuran may be about 1:2.5 to about 1:3.5.

[0258] Also, the weight ratio of the diisopropyl adipate and the cyclopentanone may be about 1:1 to about 1:5. The weight ratio of the diisopropyl adipate and the cyclopentanone may be about 1:2 to about 1:4. The weight ratio of the diisopropyl adipate and the cyclopentanone may be about 1:2.5 to about 1:3.5.

[0259] The content of the crystallization regulator can be added during the process of manufacturing the biodegradable polyester resin or can be generated by the reaction of the input raw materials. That is, in order to appropriately adjust the content of the crystallization regulator, the appropriate input amount and / or the appropriate process conditions can be adjusted during the manufacturing process.

[0260] When the crystallization regulator has the above characteristics, the biodegradable resin composition according to the examples may have appropriate crystallization characteristics and appropriate mechanical characteristics.

[0261] The biodegradable polyester resin composition according to the examples may further contain a hydrolysis-resistant agent.

[0262] The hydrolysis-resistant agent may be one in which at least one is selected from silicon-based compounds such as silane, silazane, or siloxane.

[0263] 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 selected from the group consisting of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-Glycidoxypropyl methyldimethoxysilane, 3-Glycidoxypropyl trimethoxysilane, 3-Glycidoxypropyl methyldiethoxysilane, or 3-Glycidoxypropyl triethoxysilane.

[0264] The hydrolysis-resistant agent may be contained in the biodegradable polyester resin composition according to the examples at a content of about 1 ppm to about 30,000 ppm. The hydrolysis-resistant agent may be contained in the biodegradable polyester resin composition according to the examples at a content 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 at a content of about 5 ppm to 5,000 ppm. The hydrolysis-resistant agent may be contained in the biodegradable polyester resin composition according to the examples at a content of about 10 ppm to 1,000 ppm.

[0265] The hydrolysis-resistant agent may be bound to the biodegradable polyester resin. The hydrolysis-resistant agent may be chemically bound to the biodegradable polyester resin. The hydrolysis-resistant agent may be chemically bound 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.

[0266] Since the biodegradable polyester resin composition according to the examples contains the hydrolysis-resistant agent within the above range, it may have appropriate hydrolysis-resistant properties. In particular, since the biodegradable polyester resin according to the examples contains the hydrolysis-resistant agent within the above range, it may have appropriate initial hydrolysis properties and improved biodegradability.

[0267] Accordingly, 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 1,000 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 500 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 100 ppm.

[0268] In addition, the hydrolysis-resistant agent can also react with the terminal carboxyl group or the unreacted carboxyl group. As a result, the biodegradable polyester resin composition according to the examples may have a low acid value.

[0269] In addition, the hydrolysis-resistant agent 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 the high-molecular-weight polymer. As a result, the mechanical properties of the biodegradable polyester resin composition according to the examples can be improved.

[0270] The biodegradable polyester resin composition according to the examples may further contain a chain extender.

[0271] The chain extender may contain isocyanate.

[0272] The chain extender may be selected from at least one or more of the group consisting of monofunctional isocyanate and polyfunctional isocyanate.

[0273] The chain extender may be selected from at least one or more of 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).

[0274] The chain extender may contain triisocyanate. The chain extender may contain tris(4-isocyanatophenyl)methane.

[0275] 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.

[0276] The chain extender may contain a styrene copolymer. The chain extender may contain styrene glycidyl acrylate.

[0277] The chain extender may chemically bond to the biodegradable polyester resin. The chain extender may chemically bond to a polymer contained in the biodegradable polyester resin. The chain extender may bond to the end of a polymer contained in the biodegradable polyester resin. Further, the chain extender may bond to the ends of three polymers contained in the biodegradable polyester resin.

[0278] The chain extender may be contained in the biodegradable polyester resin composition according to the examples in an amount of about 0.1 wt% to about 10 wt%. The chain extender may be contained in the biodegradable polyester resin composition according to the examples in an amount of about 0.2 wt% to about 8 wt%. The chain extender may be contained in the biodegradable polyester resin composition according to the examples in an amount of about 0.3 wt% to about 7 wt%.

[0279] 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.

[0280] Also, the chain extender can react with terminal carboxyl groups or unreacted carboxyl groups. Thereby, the biodegradable polyester resin composition according to the examples may have a low acid value.

[0281] In addition, 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. Thereby, the mechanical properties of the biodegradable polyester resin composition according to the examples can be improved.

[0282] The biodegradable polyester resin composition according to the examples may contain an oligomer. The molecular weight of the oligomer may be about 400 to about 1300.

[0283] The oligomer may be contained in the biodegradable polyester resin composition according to the examples at about 3000 ppm to about 30000 ppm based on the entire resin composition. The oligomer may be contained in the biodegradable polyester resin composition according to the examples at about 5000 ppm to about 20000 ppm based on the entire resin composition. The oligomer may be contained in the biodegradable polyester resin composition according to the examples at about 5000 ppm to about 15000 ppm based on the entire resin composition. The oligomer may be contained in the biodegradable polyester resin composition according to the examples at about 7000 ppm to about 15000 ppm based on the entire resin composition.

[0284] 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.

[0285] The oligomer may contain 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 proportion of the oligomer containing relatively more aliphatic dicarboxylic acid may be even higher than the proportion of the oligomer containing relatively more aromatic dicarboxylic acid.

[0286] 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.

[0287] Also, the oligomer can appropriately adjust the degree of biodegradation of the biodegradable polyester resin composition according to the examples. The oligomer may be a biodegradation regulator that appropriately adjusts the degree of biodegradation of the biodegradable polyester resin composition according to the examples.

[0288] The biodegradable polyester resin composition according to the examples may contain a heat stabilizer. The heat stabilizer may be a phosphorus-based heat stabilizer.

[0289] The heat stabilizer may be at least one selected from the group consisting of amine-based high-temperature heat stabilizers such as tetraethylenepentamine, triethylphosphonoacetate, phosphoric acid, phosphorous acid, polyphosphric acid, trimethyl phosphate (TMP), triethyl phosphate, trimethyl phosphine, or triphenyl phosphine.

[0290] Also, the heat stabilizer may be an antioxidant having an antioxidant function.

[0291] 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, 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.

[0292] 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, whiting 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.

[0293] 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.

[0294] Further, 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 m 2 / g or more.

[0295] The inorganic filler may be included in the biodegradable polyester resin composition according to the examples in an amount 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 in an amount of about 5 parts by weight to about 30 parts by weight based on 100 parts by weight of the biodegradable polyester resin.

[0296] The inorganic filler may be included in the biodegradable polyester resin composition according to the examples in an amount 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.

[0297] Since the biodegradable polyester resin composition according to the examples contains the inorganic filler in 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.

[0298] The biodegradable polyester resin composition according to the examples may further contain two types of biodegradable 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.

[0299] At least one of the two types of biodegradable resins may be selected from the group consisting of polybutylene azelate terephthalate (PBAzT), polybutylene sebacate terephthalate (PBSeT), polybutylene succinate terephthalate (PBST), polyhydroxyalkanoate (PHA), or polylactic acid (PLA).

[0300] The two biodegradable resins may be included in the biodegradable polyester resin composition according to the examples in an amount 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 resins may be included in the biodegradable polyester resin composition according to the examples in an amount 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 resins may be included in the biodegradable polyester resin composition according to the examples in an amount of about 20 parts by weight to about 50 parts by weight based on 100 parts by weight of the biodegradable polyester resin.

[0301] The two biodegradable 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 resins in 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.

[0302] Also, the number of terminal carboxyl groups of 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 of 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.

[0303] 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.

[0304] The process by which the biodegradable polyester resin composition according to the examples is manufactured is as follows.

[0305] 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.

[0306] The method for manufacturing the biodegradable polyester resin includes a step of manufacturing a slurry containing the diol and the aromatic dicarboxylic acid.

[0307] The step of manufacturing the slurry includes a step of mixing and treating the diol and the aromatic dicarboxylic acid. That is, the step of manufacturing the slurry may be a pretreatment step before the esterification reaction, and may be a step of mixing the diol and the aromatic dicarboxylic acid and slurrying them. At this time, the diol may contain a biomass-based diol component.

[0308] 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.

[0309] The diol and the aromatic dicarboxylic acid can be charged into the slurry stirrer 100 and stirred to produce the slurry.

[0310] By mixing and pre-treating 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 causing the esterification reaction rate, so the reaction efficiency can be enhanced.

[0311] In particular, when the aromatic dicarboxylic acid has complete crystallinity and is in powder form like terephthalic acid, its solubility in the diol is very low, and a homogeneous reaction may be difficult to occur. Therefore, the pre-treatment process of forming the slurry can play a very important role in providing biodegradable polyester resins, sheets, films, and molded products with excellent physical properties according to the embodiments of the present invention and enhancing the reaction efficiency.

[0312] When the aromatic dicarboxylic acid is terephthalic acid, the terephthalic acid has complete crystallinity, is a white crystal that sublimes at nearly 300°C under normal pressure without a melting point, and has a very low solubility in the diol, so a homogeneous reaction is difficult to occur. Therefore, when a pre-treatment process is performed 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.

[0313] Also, when the aromatic dicarboxylic acid is dimethyl terephthalate, the pre-treatment process can melt the dimethyl terephthalate at about 142°C to 170°C and react it with the diol, so the esterification reaction rate can be made even faster and more efficient.

[0314] On the one 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.

[0315] For example, the aromatic dicarboxylic acid includes 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 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 diol and the reaction rate.

[0316] In the pretreatment step, the diol and the aromatic dicarboxylic acid can be mixed and charged into a slurry stirrer 100 (tank).

[0317] The slurry stirrer 100 may be, for example, an anchor type at the bottom, the height to the agitator is 20 mm or more, and the one equipped with three or more rotating blades may be more advantageous for achieving an efficient stirring effect.

[0318] For example, the slurry stirrer 100 may have a height to the agitator of 20 mm or more, that is, there may be almost a connection 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 satisfy 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.

[0319] The pretreatment step of 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.

[0320] The diol may have the characteristics as described above.

[0321] The diol can be charged all at once or in portions. For example, the diol can be charged separately when mixing with the aromatic dicarboxylic acid and when mixing with the aliphatic dicarboxylic acid.

[0322] The aromatic dicarboxylic acid may have the same characteristics as described above.

[0323] In the pretreatment step 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 step 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 step 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.

[0324] When the diol is charged in a larger amount than the aromatic dicarboxylic acid, the aromatic dicarboxylic acid can be easily dispersed.

[0325] Also, an additive can be added to the slurry. The nanocellulose, the elongation improver, and / or the crystallization regulator may be added to the slurry in the form of a dispersion or a solution.

[0326] The method for producing the biodegradable polyester resin esterifies a slurry obtained by mixing and pre-treating a diol and an aromatic dicarboxylic acid 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 embodiments of the present invention can be efficiently achieved.

[0327] The method for producing the biodegradable polyester resin includes a step of esterifying the slurry and the aliphatic dicarboxylic acid to produce a prepolymer. The slurry and the aliphatic dicarboxylic acid can react in the ester reaction section.

[0328] In the esterification reaction, by using the slurry, the reaction time can be shortened. For example, the slurry obtained in the pre-treatment step can shorten the reaction time of the ester reaction by 1.5 times or more.

[0329] The esterification reaction can be carried out at least once or more. The prepolymer to be introduced into the polycondensation step can be formed by the esterification reaction.

[0330] In one embodiment, the esterification reaction can be carried out once after adding an aliphatic dicarboxylic acid, or a diol and an aliphatic dicarboxylic acid to the slurry. That is, the slurry is introduced into the esterification reactor, and the esterification reaction can be carried out by introducing the aliphatic dicarboxylic acid alone, or the aliphatic dicarboxylic acid and the diol into the esterification reactor.

[0331] The diol and the aliphatic dicarboxylic acid may be added to the slurry containing the aromatic dicarboxylic acid in a slurry state.

[0332] 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.

[0333] In the esterification reaction, the molar number of the total diol charged may be about 1.0 to about 1.8 relative 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 charged may be about 1.1 to about 1.6 relative to the total molar number of the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid.

[0334] 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.

[0335] Also, various additives such as the nanocellulose may be added to the slurry of the diol and the aliphatic dicarboxylic acid.

[0336] 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.

[0337] In one embodiment, the slurry, the aliphatic dicarboxylic acid and the diol can be mixed to carry out a first esterification reaction. At this time, in the reaction mixture for carrying out the first esterification reaction, the molar ratio of the aromatic dicarboxylic acid to the aliphatic dicarboxylic acid may be 1:0.05 to 1:0.5.

[0338] Also, after the first ester reaction, a mixture of the slurry, 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. At this time, in the mixture introduced in the second esterification reaction, the molar ratio of the aromatic dicarboxylic acid to the aliphatic dicarboxylic acid may be 0.05:1 to 0.5:1.

[0339] 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.

[0340] 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.

[0341] In the first esterification reaction and the second esterification reaction, the reaction temperature, reaction time, and the contents of the diol, aromatic dicarboxylic acid, and aliphatic dicarboxylic acid introduced are adjusted respectively, so that the ratio of the number of the first block and the second block, the crosslinking ratio, the proportion of the hard segment, and the proportion of the soft segment can be adjusted. Also, when the esterification reaction is carried out separately as the first esterification reaction and the second esterification reaction, the overall esterification reaction can be precisely controlled. Thereby, when the esterification reaction is carried out separately, the reaction stability and reaction uniformity of the esterification reaction can be improved.

[0342] Moreover, in the second esterification reaction, the branching agent can be further added. That is, a mixture of the slurry, the aliphatic dicarboxylic acid, the diol, the branching agent, and the product of the first esterification reaction can react to form the prepolymer. The characteristics and content of the branching agent may be the same as those described above.

[0343] In the second esterification reaction, a prepolymer can be formed.

[0344] In contrast, after the second esterification reaction, a third esterification reaction can be carried out to form the prepolymer.

[0345] After the second esterification reaction is completed, a third esterification reaction can be carried out. At this time, a monomer composition containing at least one or more of the diol, the aromatic dicarboxylic acid, and the aliphatic dicarboxylic acid is added to the product of the second esterification reaction, and the third esterification reaction can be carried out.

[0346] The monomer composition may be added to the product of the second esterification reaction at a content of about 0.5 parts by weight to about 10 parts by weight based on 100 parts by weight of the product of the second esterification reaction.

[0347] In addition, in the monomer composition, the molar ratio of the aromatic dicarboxylic acid to the aliphatic dicarboxylic acid may be about 1:1 to about 1:3. In the monomer composition, the molar ratio of the aromatic dicarboxylic acid to the aliphatic dicarboxylic acid may be about 1:1.3 to about 1:3.

[0348] In addition, in the monomer composition, the molar ratio of the diol to the total dicarboxylic acid may be about 0.8:1 to 1:1.2.

[0349] The third esterification reaction can be carried out at about 250 °C or lower for 0.1 hour to 0.5 hour. Specifically, the third 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. For example, the third esterification reaction can be carried out for 5 minutes to 60 minutes, 10 minutes to 50 minutes or 10 minutes to 40 minutes, but is not limited thereto.

[0350] A prepolymer can be formed by the third esterification reaction.

[0351] When the third esterification reaction is carried out under the above process conditions using the monomer composition as described above, the crosslinking ratio, the ratio of the hard segment, and the ratio of the soft segment can be appropriately adjusted.

[0352] In the third esterification reaction, the product of the second esterification reaction may not be used. That is, the third esterification reaction can be carried out with the monomer composition and other additive substances such as a catalyst. Thereafter, the product of the second esterification reaction and the product of the third esterification reaction can be mixed with each other to produce the prepolymer. At this time, the product of the third esterification reaction can be mixed with the product of the second esterification reaction at a content of about 0.1 part by weight to about 5 parts by weight based on 100 parts by weight of the product of the second esterification reaction to produce the prepolymer.

[0353] 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.

[0354] 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).

[0355] The reinforcing material, the elongation improver and / or the crystallization regulator may be introduced together with the slurry before the esterification reaction. The reinforcing material, the elongation improver and / or the crystallization regulator may be introduced into the esterification reaction section 200 during the esterification reaction. The reinforcing material, the elongation improver and / or the crystallization regulator may be introduced into the ester reaction product after the esterification reaction. Also, the reinforcing material, the elongation improver and / or the crystallization regulator may be introduced together with the aliphatic dicarboxylic acid. Also, the reinforcing material, the elongation improver and / or the crystallization regulator may be introduced into the esterification reaction section 200 after the first ester reaction and before the second ester reaction.

[0356] Since the reinforcing material, the elongation improver and / or the crystallization regulator are introduced into the esterification reaction, the reinforcing material, the elongation improver and / or the crystallization regulator may be uniformly dispersed in the biodegradable polyester resin.

[0357] The reinforcing material may have the features described above. In particular, the nanocellulose can be used as the reinforcing material.

[0358] The elongation rate improver and the crystallization regulator may have the features described above.

[0359] 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 the form of water-dispersed nanocellulose.

[0360] For now, the bead mill pretreatment can be performed using a vertical mill or a horizontal mill as a wet milling device. Although the horizontal mill is preferred in that it can hold a greater amount of beads inside the chamber, reduces uneven wear of the machine, reduces wear of the beads, and is easy to maintain, it is not limited thereto.

[0361] The bead mill pretreatment can be carried out using one or more beads selected from the group consisting of zirconium, zircon, zirconia, quartz, and aluminum oxide.

[0362] Specifically, the bead mill pretreatment can be carried out 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.

[0363] By having the diameter of the beads fall within the above range, the dispersibility of the nanocellulose can be further improved. If the diameter of the beads exceeds the above range, the average particle size and particle size deviation of the nanocellulose may increase, resulting in lower dispersibility.

[0364] Also, it is preferable to use beads with a specific gravity higher than that of nanocellulose in the bead mill pretreatment in terms of sufficient energy transfer. 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. Zirconium beads having a specific gravity 4 times or more higher than that of the water-dispersed nanocellulose are preferable, but not limited thereto.

[0365] 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.

[0366] 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.

[0367] 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 ultrasonic pretreatment after bead mill pretreatment in terms of preventing re-aggregation and improving dispersibility.

[0368] 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 ultrasonic pretreatment after bead mill pretreatment in terms of preventing re-aggregation and improving dispersibility.

[0369] 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%.

[0370] A titanium-based catalyst and / or a germanium-based catalyst can be used in 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.

[0371] 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.

[0372] 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.

[0373] Further, the content of the catalyst may be about 50 ppm to 2000 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 1600 ppm, about 70 ppm to about 1400 ppm, about 80 ppm to about 1200 ppm, or about 100 ppm to about 1100 ppm. By satisfying the above range of the catalyst content, the physical properties can be further improved.

[0374] Further, 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. Further, the heat stabilizer may be introduced together with the aliphatic dicarboxylic acid. Further, the heat stabilizer may be introduced into the esterification reaction section 200 after the first ester reaction and before the second ester reaction.

[0375] The characteristics of the heat stabilizer may be the same as those described above.

[0376] 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 satisfying the above range of the heat stabilizer content, the degradation 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.

[0377] 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, after the additive and / or color corrector is added and stabilized, a 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 unit 300 together with the prepolymer. Thereby, the additive and / or the color corrector may be uniformly dispersed in the biodegradable polyester resin.

[0378] 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, after the inorganic filler is introduced and stabilized, 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 unit 300 together with the prepolymer to carry out the polycondensation step. Thereby, the inorganic filler can be uniformly dispersed in the biodegradable polyester resin.

[0379] Also, the first recovery unit 510 recovers reaction by-products such as water from the esterification reaction unit 200. The first recovery unit 510 can recover the by-products generated in the esterification reaction by applying a vacuum pressure to the esterification reaction unit 200 or performing reflux.

[0380] 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.

[0381] 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 elongation rate improver, the crystallization regulator, or other additives may be introduced into the polycondensation reaction section 300 together with the prepolymer.

[0382] 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, 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 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.

[0383] Also, the polycondensation reaction may include a primary polycondensation and a secondary polycondensation.

[0384] For example, the primary polycondensation can be 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 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.

[0385] Also, the secondary polycondensation can be 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 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.

[0386] Also, 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.

[0387] 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 satisfying the above range of the number average molecular weight of the polymer, physical properties, impact resistance, durability, and moldability can be further improved.

[0388] 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.

[0389] 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.

[0390] 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.

[0391] In contrast, the hydrolysis-resistant agent and / or the chain extender may 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.

[0392] The hydrolysis-resistant agent may have the same characteristics as described above.

[0393] The chain extender may have the same characteristics as described above.

[0394] Thereby, the biodegradable polyester resin composition according to the example may have an appropriate degree of hydrolysis and a high degree of biodegradability.

[0395] Thereafter, pellets can be produced from the polymer.

[0396] 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.

[0397] 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.

[0398] The pellets can undergo further post-treatment steps. The pellets can be introduced into the post-treatment section 400 to perform the post-treatment steps.

[0399] The post-treatment process can be performed 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.

[0400] 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.

[0401] 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.

[0402] Thereafter, the resin extruded by the extruder may be cooled, cut, and processed into post-treated pellets. That is, the resin extruded from the extruder may be reprocessed into pellets by the above-described cutting step.

[0403] 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.

[0404] Thereby, the post-treatment process can appropriately adjust the mechanical properties, biodegradability, UV resistance, optical properties, or hydrolysis resistance of the biodegradable polyester resin.

[0405] After the pellets are manufactured, the biodegradable polyester resin can be compounded with the two biodegradable 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 resins.

[0406] The compounding process is as follows.

[0407] The biodegradable polyester resin and the two biodegradable resins are mixed with at least one or more of the inorganic filler, the heat stabilizer, the color corrector, the elongation improver, the crystallization regulator, or the other additives and then fed into an extruder. The mixed biodegradable polyester resin composition is melted at a temperature of about 120°C to about 260°C in the extruder and mixed with each other. Then, the melt-mixed biodegradable polyester resin composition is extruded, cooled, cut, and re-pelletized. Through such a process, the two biodegradable resins can be compounded to produce the biodegradable polyester resin composition according to the examples.

[0408] Alternatively, the inorganic filler, the heat stabilizer, the color corrector, the elongation improver, the crystallization regulator, and the other additives may be added during the polymerization process of the biodegradable polyester resin.

[0409] A biodegradable polyester film can be produced from the biodegradable polyester resin composition according to the examples.

[0410] 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.

[0411] The biodegradable polyester film according to the embodiment may have a hydrolysis degree and a biodegradability substantially similar to those of the biodegradable polyester resin composition described above.

[0412] On the other hand, the biodegradable polyester film can be produced using the biodegradable polyester resin or biodegradable polyester resin pellets.

[0413] Specifically, the method for producing the biodegradable polyester film may include a step of producing a biodegradable polyester resin composition according to the embodiment, and a step of drying and melt-extruding the biodegradable polyester resin composition.

[0414] In the step of drying and melt-extruding the biodegradable polyester 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 produced biodegradable polyester film or molded product can be further improved. The moisture content of the biodegradable polyester resin composition after the drying step may be about 500 ppm or less based on the total weight of the biodegradable polyester resin composition.

[0415] In the step of drying and melt-extruding, the melt-extrusion can be performed at a temperature of about 250°C or lower. For example, the melt-extrusion can be performed at a temperature of about 245°C or lower, about 220°C or lower, about 215°C or lower, about 100°C to about 250°C, about 120°C to about 245°C, or about 130°C to about 215°C. The melt-extrusion can be performed in a blown film process. The melt-extrusion can be performed using a T-die.

[0416] Also, the film production process may be a calendaring process.

[0417] A biodegradable polyester molded article can be manufactured using the biodegradable polyester resin.

[0418] Specifically, the molded article can be manufactured by molding the biodegradable polyester resin composition by known methods in the industry such as extrusion and 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.

[0419] 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, weigh - in - motion garbage bags, etc., or may be in the form of fibers used for textiles, knitted fabrics, non - woven fabrics, ropes, etc. Also, as shown in FIG. 3, the molded article may be a disposable container 10 used for food packaging containers such as bento boxes. Further, the molded article may be molded articles in various forms such as disposable straws, spoons, eating plates, forks, etc.

[0420] In particular, since the molded article can be formed of the biodegradable polyester resin which can improve not only physical properties such as impact - absorbing energy and hardness, but especially impact resistance and durability, it can exhibit excellent properties 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.

[0421] 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. Also, the biodegradable film and the biodegradable molded article may be substantially the same as the physical properties of the biodegradable polyester resin composition described below.

[0422] The tensile strength reduction rate of the biodegradable polyester resin composition according to the example can be measured by the following measurement method.

[0423] First, in order to measure the tensile strength reduction rate of the biodegradable polyester resin composition according to the example, a biodegradable polyester sheet is produced from the biodegradable polyester resin composition according to the example.

[0424] The biodegradable polyester resin composition according to the example is dried at a temperature of about 80 °C for about 1 hour, placed in a stainless steel frame, and compressed at a temperature of about 210 °C and a pressure of about 10 MPa for about 3 minutes to produce a biodegradable polyester sheet having a thickness of about 300 μm.

[0425] Thereafter, the initial tensile strength of the biodegradable polyester sheet is measured. Thereafter, the biodegradable polyester sheet is irradiated with ultraviolet rays from a UVA340 ultraviolet lamp for a certain time at a certain output. Thereafter, the tensile strength of the biodegradable polyester sheet after the ultraviolet irradiation is measured. The UVA340 ultraviolet lamp may be a fluorescent lamp that emits light of a spectrum having a maximum peak of about 340 nm. The UVA340 ultraviolet lamp may have an emission spectrum as shown in FIG. 2.

[0426] At this time, the tensile strength reduction rate is a value obtained by dividing the difference between the initial tensile strength and the tensile strength after the ultraviolet irradiation by the initial tensile strength.

[0427] For example, the tensile strength reduction rate (TR, %) may be represented by the following Mathematical formula 10.

[0428] [Mathematical formula 10] JPEG2025522289000024.jpg24128

[0429] Here, the TS1 is the initial tensile strength, and the TS2 is the tensile strength after the ultraviolet irradiation. For example, the TS2 may be the tensile strength 1 day after the ultraviolet irradiation. The TS2 may be the tensile strength 1 day after the ultraviolet irradiation. The TS2 may be the tensile strength 2 days after the ultraviolet irradiation. The TS2 may be the tensile strength 1 day after the ultraviolet irradiation. The TS2 may be the tensile strength 3 days after the ultraviolet irradiation. The TS2 may be the tensile strength 4 days after the ultraviolet irradiation. The TS2 may be the tensile strength 5 days after the ultraviolet irradiation. The TS2 may be the tensile strength 6 days after the ultraviolet irradiation. For example, the TS2 may be the tensile strength 7 days after the ultraviolet irradiation. For example, the TS2 may be the tensile strength 9 days after the ultraviolet irradiation.

[0430] Further, the reduction rate of the elongation at break of the biodegradable polyester resin composition according to the examples may be measured by the following measurement method.

[0431] First, in order to measure the reduction rate of the elongation at break of the biodegradable polyester resin composition according to the examples, a biodegradable polyester sheet is produced in the same manner as the method described above using the biodegradable polyester resin composition according to the examples.

[0432] That is, the biodegradable polyester resin composition according to the examples is dried at a temperature of about 80°C for about 1 hour, placed in a stainless steel frame, compressed at a temperature of about 210°C and a pressure of about 10 MPa for about 3 minutes, and a biodegradable polyester sheet having a thickness of about 300 μm can be produced.

[0433] Thereafter, the initial elongation at break of the biodegradable polyester sheet is measured. Thereafter, the biodegradable polyester sheet is irradiated with ultraviolet rays from a UVA340 ultraviolet lamp for a certain time and at a certain output. Thereafter, the elongation at break of the biodegradable polyester sheet after the ultraviolet irradiation is measured.

[0434] At this time, the elongation at break reduction rate is a value obtained by dividing the difference between the initial elongation at break and the elongation at break after ultraviolet irradiation by the initial elongation at break.

[0435] For example, the elongation at break reduction rate (ER, %) may be represented by the following Mathematical Formula 12.

[0436] [Mathematical Formula 12] JPEG2025522289000025.jpg19128

[0437] Here, EL1 is the initial elongation at break, and EL2 is the elongation at break after ultraviolet irradiation. For example, EL2 may be the elongation at break 1 day after ultraviolet irradiation. For example, EL2 may be the elongation at break 2 days after ultraviolet irradiation. For example, EL2 may be the elongation at break 3 days after ultraviolet irradiation. For example, EL2 may be the elongation at break 4 days after ultraviolet irradiation. For example, EL2 may be the elongation at break 5 days after ultraviolet irradiation. For example, EL2 may be the elongation at break 6 days after ultraviolet irradiation. For example, EL2 may be the elongation at break 7 days after ultraviolet irradiation. For example, EL2 may be the elongation at break 9 days after ultraviolet irradiation.

[0438] The tensile strength and the elongation at break may be measured by the following method. After a biodegradable polyester sheet according to an example is cut into specimens based on ASTM D638 Type V, an experiment is carried out at a tensile speed of 100 mm / min using a universal testing machine (UTM, model name 4206-001) of INSTRON Corporation, and then the tensile strength (kgf / mm 2 = 9.8 Mpa) and the elongation at break can be measured by a program installed in the equipment.

[0439] In the biodegradable polyester resin composition according to the example, ultraviolet rays from a UVA340 ultraviolet lamp are about 0.75 W / m 2When continuously irradiated at a strength of, the tensile strength reduction rate from the initial stage to 1 day of the ultraviolet irradiation may be about 5% to about 40%. In the biodegradable polyester resin composition according to the example, ultraviolet rays from a UVA340 ultraviolet lamp are about 0.75 W / m 2 When continuously irradiated at a strength of, the tensile strength reduction rate from the initial stage to 1 day of the ultraviolet irradiation may be about 10% to about 35%. In the biodegradable polyester resin composition according to the example, ultraviolet rays from a UVA340 ultraviolet lamp are about 0.75 W / m 2 When continuously irradiated at a strength of, the tensile strength reduction rate from the initial stage to 1 day of the ultraviolet irradiation may be about 15% to 30%.

[0440] In the biodegradable polyester resin composition according to the example, when the ultraviolet rays are continuously irradiated at a strength of about 0.75 W / m 2 When continuously irradiated at a strength of, the tensile strength reduction rate from the initial stage to 3 days of the ultraviolet irradiation may be about 40% to about 75%. In the biodegradable polyester resin composition according to the example, when the ultraviolet rays are continuously irradiated at a strength of about 0.75 W / m 2 When continuously irradiated at a strength of, the tensile strength reduction rate from the initial stage to 3 days of the ultraviolet irradiation may be about 40% to about 70%. In the biodegradable polyester resin composition according to the example, when the ultraviolet rays are continuously irradiated at a strength of about 0.75 W / m 2 When continuously irradiated at a strength of, the tensile strength reduction rate from the initial stage to 3 days of the ultraviolet irradiation may be about 50% to about 65%.

[0441] In the biodegradable polyester resin composition according to the example, when the ultraviolet rays are continuously irradiated at a strength of about 0.75 W / m 2 When continuously irradiated at a strength of, the tensile strength reduction rate from the initial stage to 6 days of the ultraviolet irradiation may be 67% or more. In the biodegradable polyester resin composition according to the example, when the ultraviolet rays are continuously irradiated at a strength of about 0.75 W / m 2 When continuously irradiated at a strength of, the tensile strength reduction rate from the initial stage to 6 days of the ultraviolet irradiation may be 70% or more. In the biodegradable polyester resin composition according to the example, when the ultraviolet rays are continuously irradiated at a strength of about 0.75 W / m 2When continuously irradiated with the strength of, the tensile strength reduction rate from the initial stage to 6 days of the ultraviolet irradiation may be about 72% or more. In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is about 0.75 W / m 2 When continuously irradiated with the strength of, the tensile strength reduction rate from the initial stage to 6 days of the ultraviolet irradiation may be about 75% or more.

[0442] In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is about 0.75 W / m 2 When continuously irradiated with the strength of, the tensile strength reduction rate from the initial stage to 7 days of the ultraviolet irradiation may be about 70% or more. In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is about 0.75 W / m 2 When continuously irradiated with the strength of, the tensile strength reduction rate from the initial stage to 7 days of the ultraviolet irradiation may be about 75% or more. In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is about 0.75 W / m 2 When continuously irradiated with the strength of, the tensile strength reduction rate from the initial stage to 7 days of the ultraviolet irradiation may be about 80% or more.

[0443] In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is about 0.75 W / m 2 When continuously irradiated with the strength of, the difference between the tensile strength reduction rate from the initial stage to 1 day of the ultraviolet irradiation and the tensile strength reduction rate from the initial stage to 3 days of the ultraviolet irradiation may be about 25% to about 50%. In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is about 0.75 W / m 2 When continuously irradiated with the strength of, the difference between the tensile strength reduction rate from the initial stage to 1 day of the ultraviolet irradiation and the tensile strength reduction rate from the initial stage to 3 days of the ultraviolet irradiation may be about 29% to about 45%.

[0444] In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is about 0.75 W / m 2When continuously irradiated at the strength of, the difference between the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 3 days and the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 6 days may be about 7% to about 20%. In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is about 0.75W / m 2 When continuously irradiated at the strength of, the difference between the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 3 days and the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 6 days may be about 9% to about 17%.

[0445] In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is about 0.75W / m 2 When continuously irradiated at the strength of, the difference between the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 6 days and the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 7 days may be about 5% or less. In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is about 0.75W / m 2 When continuously irradiated at the strength of, the difference between the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 6 days and the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 7 days may be about 3% or less.

[0446] In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is about 0.35W / m 2 When irradiated at the strength of, the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 1 day may be about 1% to about 30%. In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is about 0.35W / m 2 When irradiated at the strength of, the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 1 day may be about 5% to about 25%. In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is about 0.35W / m 2 When irradiated at the strength of, the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 1 day may be about 10% to about 20%.

[0447] In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is about 0.35W / m 2When irradiated with the strength of, the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 2 days may be about 25% to about 50%. In the biodegradable polyester resin composition according to the example, the ultraviolet ray is about 0.35 W / m 2 When irradiated with the strength of, the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 2 days may be about 30% to about 50%. In the biodegradable polyester resin composition according to the example, the ultraviolet ray is about 0.35 W / m 2 When irradiated with the strength of, the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 2 days may be about 30% to about 45%.

[0448] In the biodegradable polyester resin composition according to the example, the ultraviolet ray is about 0.35 W / m 2 When irradiated with the strength of, the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 3 days may be about 40% to about 55%. In the biodegradable polyester resin composition according to the example, the ultraviolet ray is about 0.35 W / m 2 When irradiated with the strength of, the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 3 days may be about 45% to about 55%. In the biodegradable polyester resin composition according to the example, the ultraviolet ray is about 0.35 W / m 2 When irradiated with the strength of, the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 3 days may be about 45% to about 50%.

[0449] In the biodegradable polyester resin composition according to the example, the ultraviolet ray is about 0.35 W / m 2 When irradiated with the strength of, the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 7 days may be about 55% to about 95%. In the biodegradable polyester resin composition according to the example, the ultraviolet ray is about 0.35 W / m 2 When irradiated with the strength of, the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 7 days may be about 60% to about 95%. In the biodegradable polyester resin composition according to the example, the ultraviolet ray is about 0.35 W / m 2 When irradiated with the strength of, the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 7 days may be about 65% to about 90%.

[0450] In the biodegradable polyester resin composition according to the examples, when irradiated with the ultraviolet light at a strength of about 0.35 W / m 2 , the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 9 days may be about 65% or more. In the biodegradable polyester resin composition according to the examples, when irradiated with the ultraviolet light at a strength of about 0.35 W / m 2 , the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 9 days may be about 68% or more. In the biodegradable polyester resin composition according to the examples, when irradiated with the ultraviolet light at a strength of about 0.35 W / m 2 , the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 9 days may be about 70% or more. In the biodegradable polyester resin composition according to the examples, when irradiated with the ultraviolet light at a strength of about 0.35 W / m 2 , the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 9 days may be about 72% or more.

[0451] In the biodegradable polyester resin composition according to the examples, when continuously irradiated with the ultraviolet light at a strength of about 0.35 W / m 2 , the difference between the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 1 day and the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 2 days may be about 10% to about 35%. In the biodegradable polyester resin composition according to the examples, when continuously irradiated with the ultraviolet light at a strength of about 0.35 W / m 2 , the difference between the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 1 day and the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 2 days may be about 15% to about 30%.

[0452] In the biodegradable polyester resin composition according to the examples, when continuously irradiated with the ultraviolet light at a strength of about 0.35 W / m 2 , the difference between the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 2 days and the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 3 days may be about 5% to about 20%. In the biodegradable polyester resin composition according to the examples, when continuously irradiated with the ultraviolet light at a strength of about 0.35 W / m2 When continuously irradiated with the ultraviolet light at the intensity of, the difference between the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 2 days and the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 3 days may be about 8% to about 15%.

[0453] In the biodegradable polyester resin composition according to the example, when the ultraviolet light is continuously irradiated at the intensity of about 0.35W / m 2 When continuously irradiated with the ultraviolet light at the intensity of, the difference between the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 3 days and the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 7 days may be about 17% to about 27%. In the biodegradable polyester resin composition according to the example, when the ultraviolet light is continuously irradiated at the intensity of about 0.35W / m 2 When continuously irradiated with the ultraviolet light at the intensity of, the difference between the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 3 days and the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 7 days may be about 20% to about 25%.

[0454] In the biodegradable polyester resin composition according to the example, when the ultraviolet light is continuously irradiated at the intensity of about 0.35W / m 2 When continuously irradiated with the ultraviolet light at the intensity of, the difference between the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 7 days and the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 9 days may be about 15% or less. In the biodegradable polyester resin composition according to the example, when the ultraviolet light is continuously irradiated at the intensity of about 0.35W / m 2 When continuously irradiated with the ultraviolet light at the intensity of, the difference between the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 7 days and the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 9 days may be about 10% or less. In the biodegradable polyester resin composition according to the example, when the ultraviolet light is continuously irradiated at the intensity of about 0.35W / m 2 When continuously irradiated with the ultraviolet light at the intensity of, the difference between the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 7 days and the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 9 days may be about 7% or less.

[0455] In the biodegradable polyester resin composition according to the embodiment, the initial tensile strength may be about 30 MPa to about 60 MPa. In the biodegradable polyester resin composition according to the embodiment, the initial tensile strength may be about 35 MPa to about 60 MPa. In the biodegradable polyester resin composition according to the embodiment, the initial tensile strength may be about 40 MPa to about 60 MPa. In the biodegradable polyester resin composition according to the embodiment, the initial tensile strength may be about 45 MPa to about 60 MPa.

[0456] In the biodegradable polyester resin composition according to the embodiment, when the ultraviolet ray is continuously irradiated at a strength of about 0.75 W / m 2 the tensile strength after 1 day may be about 27 MPa to about 37 MPa. In the biodegradable polyester resin composition according to the embodiment, when the ultraviolet ray is continuously irradiated at a strength of about 0.75 W / m 2 the tensile strength after 1 day may be about 30 MPa to about 37 MPa. In the biodegradable polyester resin composition according to the embodiment, when the ultraviolet ray is continuously irradiated at a strength of about 0.75 W / m 2 the tensile strength after 7 days may be about 30 MPa to about 35 MPa.

[0457] In the biodegradable polyester resin composition according to the embodiment, when the ultraviolet ray is continuously irradiated at a strength of about 0.75 W / m 2 the tensile strength after 3 days may be about 13 MPa to about 20 MPa. In the biodegradable polyester resin composition according to the embodiment, when the ultraviolet ray is continuously irradiated at a strength of about 0.75 W / m 2 the tensile strength after 3 days may be about 15 MPa to about 19 MPa. In the biodegradable polyester resin composition according to the embodiment, when the ultraviolet ray is continuously irradiated at a strength of about 0.75 W / m 2 the tensile strength after 3 days may be about 16 MPa to about 18 MPa.

[0458] In the biodegradable polyester resin composition according to the embodiment, when the ultraviolet ray is continuously irradiated at a strength of about 0.75 W / m 2When continuously irradiated with a strength of, the tensile strength after 6 days may be about 2 MPa to about 15 MPa. In the biodegradable polyester resin composition according to the example, when the ultraviolet light is about 0.75 W / m 2 When continuously irradiated with a strength of, the tensile strength after 6 days may be about 7 MPa to about 13 MPa. In the biodegradable polyester resin composition according to the example, when the ultraviolet light is about 0.75 W / m 2 When continuously irradiated with a strength of, the tensile strength after 6 days may be about 8 MPa to about 12 MPa.

[0459] In the biodegradable polyester resin composition according to the example, when the ultraviolet light is about 0.75 W / m 2 When continuously irradiated with a strength of, the tensile strength after 7 days may be about 1 MPa to about 15 MPa. In the biodegradable polyester resin composition according to the example, when the ultraviolet light is about 0.75 W / m 2 When continuously irradiated with a strength of, the tensile strength after 7 days may be about 5 MPa to about 13 MPa. In the biodegradable polyester resin composition according to the example, when the ultraviolet light is about 0.75 W / m 2 When continuously irradiated with a strength of, the tensile strength after 7 days may be about 7 MPa to about 12 MPa.

[0460] In the biodegradable polyester resin composition according to the example, when the ultraviolet light is about 0.75 W / m 2 When continuously irradiated with a strength of, the reduction rate of the elongation at break from the initial stage to 1 day of the ultraviolet irradiation may be about 5% to about 40%. In the biodegradable polyester resin composition according to the example, when the ultraviolet light is about 0.75 W / m 2 When continuously irradiated with a strength of, the reduction rate of the elongation at break from the initial stage to 1 day of the ultraviolet irradiation may be about 5% to about 30%. In the biodegradable polyester resin composition according to the example, when the ultraviolet light is about 0.75 W / m 2 When continuously irradiated with a strength of, the reduction rate of the elongation at break from the initial stage to 1 day of the ultraviolet irradiation may be about 5% to about 27%. In the biodegradable polyester resin composition according to the example, when the ultraviolet light is about 0.75 W / m2 When continuously irradiated with the strength of, the reduction rate of the elongation at break from the initial stage to 1 day of the ultraviolet irradiation may be about 10% to about 25%.

[0461] In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is continuously irradiated with the strength of about 0.75 W / m 2 When continuously irradiated with the strength of, the reduction rate of the elongation at break from the initial stage to 3 days of the ultraviolet irradiation may be about 50% to about 70%. In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is continuously irradiated with the strength of about 0.75 W / m 2 When continuously irradiated with the strength of, the reduction rate of the elongation at break from the initial stage to 3 days of the ultraviolet irradiation may be about 55% to about 65%.

[0462] In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is continuously irradiated with the strength of about 0.75 W / m 2 When continuously irradiated with the strength of, the reduction rate of the elongation at break from the initial stage to 6 days of the ultraviolet irradiation may be about 70% or more. In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is continuously irradiated with the strength of about 0.75 W / m 2 When continuously irradiated with the strength of, the reduction rate of the elongation at break from the initial stage to 6 days of the ultraviolet irradiation may be about 80% or more.

[0463] In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is continuously irradiated with the strength of about 0.75 W / m 2 When continuously irradiated with the strength of, the reduction rate of the elongation at break from the initial stage to 7 days of the ultraviolet irradiation may be about 80% or more. In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is continuously irradiated with the strength of about 0.75 W / m 2 When continuously irradiated with the strength of, the reduction rate of the elongation at break from the initial stage to 7 days of the ultraviolet irradiation may be about 85% or more. In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is continuously irradiated with the strength of about 0.75 W / m 2 When continuously irradiated with the strength of, the reduction rate of the elongation at break from the initial stage to 7 days of the ultraviolet irradiation may be about 90% or more.

[0464] In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is continuously irradiated at a strength of about 0.75 W / m 2 , the difference between the elongation at break reduction rate from the initial stage to 1 day of the ultraviolet irradiation and the elongation at break reduction rate from the initial stage to 3 days of the ultraviolet irradiation may be about 30% to about 50%. In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is continuously irradiated at a strength of about 0.75 W / m 2 , the difference between the elongation at break reduction rate from the initial stage to 1 day of the ultraviolet irradiation and the elongation at break reduction rate from the initial stage to 3 days of the ultraviolet irradiation may be about 35% to about 45%.

[0465] In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is continuously irradiated at a strength of about 0.75 W / m 2 , the difference between the elongation at break reduction rate from the initial stage to 3 days of the ultraviolet irradiation and the elongation at break reduction rate from the initial stage to 6 days of the ultraviolet irradiation may be about 20% to about 40%. In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is continuously irradiated at a strength of about 0.75 W / m 2 , the difference between the elongation at break reduction rate from the initial stage to 3 days of the ultraviolet irradiation and the elongation at break reduction rate from the initial stage to 6 days of the ultraviolet irradiation may be about 25% to about 37%.

[0466] In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is continuously irradiated at a strength of about 0.75 W / m 2 , the difference between the elongation at break reduction rate from the initial stage to 6 days of the ultraviolet irradiation and the elongation at break reduction rate from the initial stage to 7 days of the ultraviolet irradiation may be about 10% or less. In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is continuously irradiated at a strength of about 0.75 W / m 2 , the difference between the elongation at break reduction rate from the initial stage to 6 days of the ultraviolet irradiation and the elongation at break reduction rate from the initial stage to 7 days of the ultraviolet irradiation may be about 5% or less.

[0467] In the biodegradable polyester resin composition according to the example, the initial elongation at break may be about 800% to about 1200%. In the biodegradable polyester resin composition according to the example, the initial elongation at break may be about 800% to about 1100%. In the biodegradable polyester resin composition according to the example, the initial elongation at break may be about 850% to about 1050%.

[0468] In the biodegradable polyester resin composition according to the example, when the ultraviolet light is irradiated at a strength of about 0.75 W / m 2 the elongation at break one day after the start of the ultraviolet irradiation may be about 600% to about 800%. In the biodegradable polyester resin composition according to the example, when the ultraviolet light is irradiated at a strength of about 0.75 W / m 2 the elongation at break one day after the start of the ultraviolet irradiation may be about 650% to about 750%.

[0469] In the biodegradable polyester resin composition according to the example, when the ultraviolet light is irradiated at a strength of about 0.75 W / m 2 the elongation at break three days after the start of the ultraviolet irradiation may be about 300% to about 400%. In the biodegradable polyester resin composition according to the example, when the ultraviolet light is irradiated at a strength of about 0.75 W / m 2 the elongation at break three days after the start of the ultraviolet irradiation may be about 350% to about 400%.

[0470] In the biodegradable polyester resin composition according to the example, when the ultraviolet light is irradiated at a strength of about 0.75 W / m 2 the elongation at break six days after the start of the ultraviolet irradiation may be about 100% or less. In the biodegradable polyester resin composition according to the example, when the ultraviolet light is irradiated at a strength of about 0.75 W / m 2 the elongation at break six days after the start of the ultraviolet irradiation may be about 90% or less.

[0471] In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is irradiated at a strength of about 0.75 W / m 2 the elongation at break 7 days after the start of the ultraviolet irradiation may be about 90% or less. In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is irradiated at a strength of about 0.75 W / m 2 the elongation at break 7 days after the start of the ultraviolet irradiation may be about 80% or less.

[0472] In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is irradiated at a strength of about 0.75 W / m 2 the difference between the elongation at break reduction rate 1 day after the start of the ultraviolet irradiation and the elongation at break reduction rate 3 days after the start of the ultraviolet irradiation may be about 30% to about 50%.

[0473] In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is irradiated at a strength of about 0.75 W / m 2 the difference between the elongation at break reduction rate 3 days after the start of the ultraviolet irradiation and the elongation at break reduction rate 6 days after the start of the ultraviolet irradiation may be about 30% to about 40%.

[0474] In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is irradiated at a strength of about 0.75 W / m 2 the difference between the elongation at break reduction rate 6 days after the start of the ultraviolet irradiation and the elongation at break reduction rate 7 days after the start of the ultraviolet irradiation may be about 5% or less.

[0475] In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is irradiated at a strength of about 0.35 W / m 2 the elongation at break reduction rate from the start of the ultraviolet irradiation to 1 day may be about 1% to about 20%. In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is irradiated at a strength of about 0.35 W / m 2When irradiated with the strength of, the reduction rate of the elongation at break from the initial stage to 1 day of the ultraviolet irradiation may be about 2% to about 20%. In the biodegradable polyester resin composition according to the example, the ultraviolet ray is about 0.35 W / m 2 When irradiated with the strength of, the reduction rate of the elongation at break from the initial stage to 1 day of the ultraviolet irradiation may be about 3% to about 18%. In the biodegradable polyester resin composition according to the example, the ultraviolet ray is about 0.35 W / m 2 When irradiated with the strength of, the reduction rate of the elongation at break from the initial stage to 1 day of the ultraviolet irradiation may be about 3% to about 17%.

[0476] In the biodegradable polyester resin composition according to the example, the ultraviolet ray is about 0.35 W / m 2 When irradiated with the strength of, the reduction rate of the elongation at break from the initial stage to 2 days of the ultraviolet irradiation may be about 15% to about 35%. In the biodegradable polyester resin composition according to the example, the ultraviolet ray is about 0.35 W / m 2 When irradiated with the strength of, the reduction rate of the elongation at break from the initial stage to 2 days of the ultraviolet irradiation may be about 20% to about 30%.

[0477] In the biodegradable polyester resin composition according to the example, the ultraviolet ray is about 0.35 W / m 2 When irradiated with the strength of, the reduction rate of the elongation at break from the initial stage to 3 days of the ultraviolet irradiation may be about 30% to about 45%. In the biodegradable polyester resin composition according to the example, the ultraviolet ray is about 0.35 W / m 2 When irradiated with the strength of, the reduction rate of the elongation at break from the initial stage to 3 days of the ultraviolet irradiation may be about 35% to about 40%.

[0478] In the biodegradable polyester resin composition according to the example, the ultraviolet ray is about 0.35 W / m 2 When irradiated with the strength of, the reduction rate of the elongation at break from the initial stage to 7 days of the ultraviolet irradiation may be about 55% to about 75%. In the biodegradable polyester resin composition according to the example, the ultraviolet ray is about 0.35 W / m 2When irradiated with the strength of , the reduction rate of elongation at break from the initial stage of the ultraviolet irradiation to 7 days may be about 60% to about 70%.

[0479] In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is irradiated with a strength of about 0.35 W / m 2 When irradiated with the strength of , the reduction rate of elongation at break from the initial stage of the ultraviolet irradiation to 9 days may be about 80% or more. In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is irradiated with a strength of about 0.35 W / m 2 When irradiated with the strength of , the reduction rate of elongation at break from the initial stage of the ultraviolet irradiation to 9 days may be about 85% or more.

[0480] In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is irradiated with a strength of about 0.35 W / m 2 When irradiated with the strength of , the elongation at break 1 day after the initial stage of the ultraviolet irradiation may be about 700% to about 950%.

[0481] In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is irradiated with a strength of about 0.35 W / m 2 When irradiated with the strength of , the elongation at break 2 days after the initial stage of the ultraviolet irradiation may be about 600% to about 800%.

[0482] In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is irradiated with a strength of about 0.35 W / m 2 When irradiated with the strength of , the elongation at break 3 days after the initial stage of the ultraviolet irradiation may be about 500% to about 650%.

[0483] In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is irradiated with a strength of about 0.35 W / m 2 When irradiated with the strength of , the elongation at break 7 days after the initial stage of the ultraviolet irradiation may be about 250% to about 350%.

[0484] In the biodegradable polyester resin composition according to the example, when the ultraviolet ray is irradiated with a strength of about 0.35 W / m 2When irradiated with the strength of , the elongation at break after 9 days from the initial stage of the ultraviolet irradiation may be about 200% or less.

[0485] In the biodegradable polyester resin composition according to the examples, when the ultraviolet ray is irradiated with a strength of about 0.35 W / m 2 The difference between the elongation at break reduction rate from the initial stage to 1 day of the ultraviolet irradiation and the elongation at break reduction rate from the initial stage to 2 days of the ultraviolet irradiation may be about 10% to about 20%.

[0486] In the biodegradable polyester resin composition according to the examples, when the ultraviolet ray is irradiated with a strength of about 0.35 W / m 2 The difference between the elongation at break reduction rate from the initial stage to 2 days of the ultraviolet irradiation and the elongation at break reduction rate from the initial stage to 3 days of the ultraviolet irradiation may be about 8% to about 20%.

[0487] In the biodegradable polyester resin composition according to the examples, when the ultraviolet ray is irradiated with a strength of about 0.35 W / m 2 The difference between the elongation at break reduction rate from the initial stage to 3 days of the ultraviolet irradiation and the elongation at break reduction rate from the initial stage to 7 days of the ultraviolet irradiation may be about 20% to about 35%.

[0488] In the biodegradable polyester resin composition according to the examples, when the ultraviolet ray is irradiated with a strength of about 0.35 W / m 2 The difference between the elongation at break reduction rate from the initial stage to 7 days of the ultraviolet irradiation and the elongation at break reduction rate from the initial stage to 9 days of the ultraviolet irradiation may be about 20% to about 30%.

[0489] In addition, in the biodegradable polyester film according to the examples, the initial tensile strength, the tensile strength after ultraviolet irradiation, the initial elongation at break, and the elongation at break after ultraviolet irradiation can be measured based on a thickness of about 300 μm. Samples having a thickness of about 300 μm can be produced by overlapping a plurality of the biodegradable polyester films according to the examples or compressing them at appropriate pressure and temperature. The initial tensile strength, the tensile strength after ultraviolet irradiation, the initial elongation at break, and the elongation at break after ultraviolet irradiation can be measured from the samples produced as described above.

[0490] Thereby, in the biodegradable polyester film according to the examples, the rate of decrease in tensile strength and the rate of decrease in elongation at break can be derived based on a thickness of about 300 μm.

[0491] For example, the initial tensile strength of a sample from the biodegradable polyester film is measured. Thereafter, the sample from the biodegradable polyester film is irradiated with ultraviolet rays from a UVA340 ultraviolet lamp for a certain period of time at a certain output. Thereafter, the tensile strength of the biodegradable polyester sample after the ultraviolet irradiation is measured.

[0492] Also, the initial elongation at break of a sample from the biodegradable polyester film is measured. Thereafter, the sample from the biodegradable polyester film is irradiated with ultraviolet rays from a UVA340 ultraviolet lamp for a certain period of time at a certain output. Thereafter, the elongation at break of the sample from the biodegradable polyester film after the ultraviolet irradiation is measured.

[0493] The biodegradable polyester film according to the examples may have substantially the same characteristics as those of the biodegradable polyester resin composition according to the above-described examples based on a thickness of about 300 μm. That is, in the biodegradable polyester film according to the examples, the characteristics based on a thickness of about 300 μm may be substantially the same as those of the biodegradable polyester resin composition according to the above-described examples.

[0494] For example, in the biodegradable polyester film according to the embodiment, based on a thickness of about 300 μm, when irradiated continuously with ultraviolet rays from a UVA340 ultraviolet lamp at a strength of about 0.75 W / m 2 , the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 1 day may be about 5% to about 40%.

[0495] For example, in the biodegradable polyester film according to the embodiment, based on a thickness of about 300 μm, when the ultraviolet rays are continuously irradiated at a strength of about 0.75 W / m 2 , the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 3 days may be about 40% to about 65%.

[0496] For example, in the biodegradable polyester film according to the embodiment, based on a thickness of about 300 μm, when the ultraviolet rays are continuously irradiated at a strength of about 0.75 W / m 2 , the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 6 days may be about 67% or more. In the biodegradable polyester film according to the embodiment, based on a thickness of about 300 μm, when the ultraviolet rays are continuously irradiated at a strength of about 0.75 W / m 2 , the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 6 days may be about 70% or more.

[0497] For example, in the biodegradable polyester film according to the embodiment, based on a thickness of about 300 μm, when the ultraviolet rays are irradiated at a strength of about 0.35 W / m 2 , the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 1 day may be about 1% to about 20%.

[0498] For example, in the biodegradable polyester film according to the embodiment, based on a thickness of about 300 μm, when the ultraviolet rays are irradiated at a strength of about 0.35 W / m 2 , the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 9 days may be about 65% or more. In the biodegradable polyester film according to the embodiment, based on a thickness of about 300 μm, when the ultraviolet rays are irradiated at a strength of about 0.35 W / m 2When irradiated with the strength of , the tensile strength reduction rate from the initial stage of the ultraviolet irradiation to 9 days may be about 70% or more.

[0499] For example, in the biodegradable polyester film according to the examples, the initial tensile strength may be about 40 MPa to about 60 MPa.

[0500] For example, in the biodegradable polyester film according to the examples, based on a thickness of about 300 μm, when the ultraviolet light is continuously irradiated with a strength of about 0.75 W / m 2 the tensile strength after 7 days may be about 1 MPa to about 15 MPa.

[0501] For example, in the biodegradable polyester film according to the examples, based on a thickness of about 300 μm, when the ultraviolet light is continuously irradiated with a strength of about 0.75 W / m 2 the reduction rate of the elongation at break from the initial stage of the ultraviolet irradiation to 1 day may be about 5% to about 40%.

[0502] For example, in the biodegradable polyester film according to the examples, based on a thickness of about 300 μm, when the ultraviolet light is continuously irradiated with a strength of about 0.75 W / m 2 the reduction rate of the elongation at break from the initial stage of the ultraviolet irradiation to 7 days may be about 80% or more.

[0503] For example, in the biodegradable polyester film according to the examples, based on a thickness of about 300 μm, when the ultraviolet light is irradiated with a strength of 0.35 W / m 2 the reduction rate of the elongation at break from the initial stage of the ultraviolet irradiation to 1 day may be about 1% to about 20%.

[0504] For example, in the biodegradable polyester film according to the examples, based on a thickness of about 300 μm, when the ultraviolet light is irradiated with a strength of 0.35 W / m 2 the reduction rate of the elongation at break from the initial stage of the ultraviolet irradiation to 9 days may be about 80% or more.

[0505] 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), after 63 days had passed, the number average molecular weight 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 of time by the initial number average molecular weight was derived as the molecular weight reduction rate.

[0506] The molecular weight reduction rate can be derived by the following formula 13.

[0507] [Formula 13] JPEG2025522289000026.jpg11142

[0508] 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).

[0509] The molecular weight reduction rate was derived 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.

[0510] Also, the compost may contain about 40 wt% of pig manure, about 15 wt% of chicken manure, about 37 wt% of large sawdust, about 5 wt% of zeolite, and about 3 wt% of a microbial preparation.

[0511] 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).

[0512] Also, when the reduction rate of the molecular weight is measured, the biodegradable polyester resin composition according to the example is produced into a sheet having a thickness of about 300 μm. Thereafter, the produced sheet is cut into a size of about 30 mm × 30 mm to produce flakes. The flakes are mixed with the compost, and the biodegradation acceleration test is performed.

[0513] The biodegradable polyester film according to the example may have a reduction rate of the molecular weight as described above. Similarly, the biodegradable polyester film according to the example 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.

[0514] The biodegradable polyester resin composition according to the example may have a biodegradation degree of about 80% or more. The biodegradable polyester resin composition according to the example may have a biodegradation degree of about 85% or more. The biodegradable polyester resin composition according to the example may have a biodegradation degree of about 90% or more. The biodegradation degree can be derived by the following formula 14.

[0515] [Formula 14] JPEG2025522289000027.jpg12165

[0516] The biodegradability of the biodegradable polyester resin composition according to the example can be measured based on the amount of carbon dioxide generated in accordance with KS M3100-1. Specifically, a inoculum 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. Then, 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 of an aqueous phenolphthalein solution. As shown in the above formula 2, the biodegradability is derived from the ratio of the carbon dioxide generated by the biodegradable polyester resin composition to the theoretically generated amount of carbon dioxide.

[0517] 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.

[0518] The biodegradable polyester film according to the example may have the biodegradability as described above. Similarly, the biodegradable polyester film according to the example 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.

[0519] The degree of hydrolysis of the biodegradable polyester resin composition according to the example can be measured by the following method.

[0520] In order to measure the degree of hydrolysis, the biodegradable resin composition according to the above example is immersed in water at 80°C (100% RH), and then a hydrolysis acceleration test is performed. After a certain period of time has passed, the number average molecular weight of the biodegradable polyester resin composition according to the example is measured using gel permeation chromatography (GPC). The degree of hydrolysis is 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.

[0521] The degree of hydrolysis may be represented by the following Mathematical Formula 15.

[0522] [Mathematical Formula 15] JPEG2025522289000028.jpg13152

[0523] 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).

[0524] The degree of hydrolysis is 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.

[0525] 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.

[0526] In the biodegradable polyester resin composition according to the examples, the degree of hydrolysis after one week may be about 40% to about 65%. In the biodegradable polyester resin composition according to the examples, the degree of hydrolysis after one week may be about 45% to about 63%.

[0527] In the biodegradable polyester resin composition according to the examples, the degree of hydrolysis after two weeks may be about 80% to about 93%. In the biodegradable polyester resin composition according to the examples, the degree of hydrolysis after two weeks may be about 85% to about 92%.

[0528] 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%.

[0529] 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%.

[0530] 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.

[0531] 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.

[0532] Since the biodegradable polyester resin composition according to the examples has a degree of hydrolysis and an increase rate of the degree of hydrolysis within the above ranges, the biodegradable polyester resin composition according to the examples may have appropriate durability in the area of daily life and may be easily hydrolyzed at the time of disposal. That is, since the biodegradable polyester resin composition according to the examples has a degree of hydrolysis and an increase rate of the degree of hydrolysis within an appropriate range, it may have sufficient hydrolysis resistance when used for an appropriate period in disposable packaging or the like. Further, the biodegradable polyester resin composition according to the examples may be easily decomposed by hydrolysis and biodegradation after sufficient time has passed not only when discarded in soil but also when discarded in a river or the sea.

[0533] 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 2.8 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.

[0534] Since the biodegradable polyester resin composition according to the examples has an acid value in the above range, it may have hydrolysis degree characteristics and biodegradability characteristics as described above.

[0535] The biodegradable polyester resin composition according to the examples may have crystallinity.

[0536] The crystallinity of the biodegradable polyester resin composition according to the examples may be from about 5% to about 20%. The crystallinity of the biodegradable polyester resin composition according to the examples may be from about 7% to about 18%. The crystallinity of the biodegradable polyester resin composition according to the examples may be from about 8% to about 16%. The crystallinity of the biodegradable polyester resin composition according to the examples may be from about 10% to about 15%. The crystallinity of the biodegradable polyester resin composition according to the examples may be from about 11% to about 14%. The crystallinity of the biodegradable polyester resin composition according to the examples may be from about 11% to about 13%.

[0537] Also, the crystallinity of the biodegradable polyester film according to the examples may be from about 5% to about 20%. The crystallinity of the biodegradable polyester film according to the examples may be from about 7% to about 18%. The crystallinity of the biodegradable polyester film according to the examples may be from about 8% to about 16%. The crystallinity of the biodegradable polyester film according to the examples may be from about 10% to about 15%. The crystallinity of the biodegradable polyester film according to the examples may be from about 11% to about 14%. The crystallinity of the biodegradable polyester film according to the examples may be from about 11% to about 13%.

[0538] Also, the crystallinity of the biodegradable polyester molded article according to the examples may be about 5% to about 20%. The crystallinity of the biodegradable polyester molded article according to the examples may be about 7% to about 18%. The crystallinity of the biodegradable polyester molded article according to the examples may be about 8% to about 16%. The crystallinity of the biodegradable polyester molded article according to the examples may be about 10% to about 15%. The crystallinity of the biodegradable polyester molded article according to the examples may be about 11% to about 14%. The crystallinity of the biodegradable polyester molded article according to the examples may be about 11% to about 13%.

[0539] The crystallinity of the biodegradable polyester resin composition, film, and molded article according to the examples can be calculated by the following Equation 16.

[0540] [Equation 16] JPEG2025522289000029.jpg17128

[0541] Here, in order to measure the crystallinity of the biodegradable polyester resin composition, film, and molded article according to the examples, a sample having a weight of about 5 mg to about 10 mg is obtained from the biodegradable polyester resin composition, film, and molded article according to the examples.

[0542] The sample is put into a differential scanning calorimeter (e.g., Q2000, TA Instruments), and the sample is stabilized at about 25°C for about 1 minute. Then, the sample is cooled at a rate of about -5°C / min to about -70°C and heated at a rate of about 10°C / min to a temperature of about 200°C. Then, the sample is maintained at a temperature of about 200°C for about 1 minute and then cooled to about 25°C. The enthalpy change during the heating and cooling processes of the sample can be measured. At this time, the minimum point of the endothermic peak may be the melting point (Tm). Also, the point where the heat flow begins to change is the glass transition temperature (Tg), and the maximum temperature of the exothermic peak may be the crystallization temperature (Tc). Also, the ΔHm may be the area of the endothermic peak at the melting point. That is, the ΔHm may be the enthalpy of fusion of the sample. Also, the ΔHm100 is the enthalpy of fusion when the crystallinity is 100%. The ΔHm100 may be 114 J / g. Also, the cooled sample is further heated, whereby the absorption enthalpy and the exothermic enthalpy can be measured again.

[0543] Since the biodegradable polyester resin composition, film, and molded product according to the examples have a crystallinity within the above range, they may have appropriate mechanical properties, appropriate biodegradability, appropriate hydrolysis resistance, appropriate thermal properties, and appropriate chemical resistance. In particular, since the biodegradable polyester resin composition, film, and molded product according to the examples have a crystallinity within the above range, they may have appropriate flexibility.

[0544] Also, the biodegradable polyester resin composition, film, and molded product according to the examples may have tensile strength.

[0545] In the biodegradable polyester resin composition, film and molded article according to the examples, the tensile strength may be about 30 MPa to about 60 MPa. In the biodegradable polyester resin composition, film and molded article according to the examples, the tensile strength may be about 35 MPa to about 60 MPa. In the biodegradable polyester resin composition, film and molded article according to the examples, the tensile strength may be about 40 MPa to about 60 MPa. In the biodegradable polyester resin composition, film and molded article according to the examples, the tensile strength may be about 45 MPa to about 60 MPa.

[0546] In the biodegradable polyester resin composition, film and molded article according to the examples, the initial elongation at break may be about 800% to about 1200%. In the biodegradable polyester resin composition, film and molded article according to the examples, the initial elongation at break may be about 800% to about 1100%. In the biodegradable polyester resin composition, film and molded article according to the examples, the initial elongation at break may be about 850% to about 1050%.

[0547] The biodegradable polyester resin composition according to the examples can be dried at a temperature of about 80 °C for about 1 hour, placed in a stainless steel frame, compressed at a temperature of about 210 °C and a pressure of about 10 MPa for about 3 minutes to produce a biodegradable polyester sheet having a thickness of about 300 μm.

[0548] The tensile strength and the elongation at break can be measured by the following method. After a test piece is produced by cutting a biodegradable polyester sheet, film and molded article according to the examples based on ASTM D638 Type V, the experiment is carried out at a tensile speed of 100 mm / min by a universal testing machine (UTM, model name 4206-001) of INSTRON, and then the tensile strength (kgf / mm 2 =9.8 Mpa) and the elongation at break can be measured by a program installed in the equipment.

[0549] The biodegradable polyester resin composition, film, and molded article according to the examples may have hardness. The hardness may be Shore D hardness.

[0550] In the biodegradable polyester resin composition, film, and molded article according to the examples, the hardness may be about 30 to about 45 in Shore D hardness. In the biodegradable polyester resin composition, film, and molded article according to the examples, the hardness may be about 33 to about 43 in Shore D hardness. In the biodegradable polyester resin composition, film, and molded article according to the examples, the hardness may be about 35 to about 41 in Shore D hardness.

[0551] The biodegradable polyester resin composition according to the examples can be dried at a temperature of about 80°C for about 20 minutes, placed in a stainless-steel frame, and compressed at a temperature of about 210°C, a pressure of about 10 MPa, and for about 5 minutes to produce a polyester block having a thickness of about 2.5 mm.

[0552] The hardness of the biodegradable polyester resin composition according to the examples can be measured with a hardness meter using the polyester block.

[0553] The biodegradable polyester resin composition according to the examples may have an appropriate degree of crystallinity by the composition and / or process described above. Also, the film and molded article produced from the biodegradable polyester resin composition according to the examples may have an appropriate degree of crystallinity.

[0554] For example, the biodegradable polyester resin composition according to the examples contains a crystallinity regulator. Thereby, the biodegradable polyester resin composition according to the examples may have an appropriate degree of crystallinity.

[0555] In particular, during the process of manufacturing the biodegradable polyester resin composition according to the examples, a chain extension reaction and / or a post-treatment reaction can be carried out. At this time, the crystallinity regulator can be appropriately applied, and the biodegradable polyester resin composition according to the examples may have an appropriate crystallinity. For example, when the chain extension reaction and / or the post-treatment reaction is carried out, the crystallinity can increase. At this time, the crystallinity regulator can appropriately lower the crystallinity.

[0556] Accordingly, as described above, the films and molded articles produced from the biodegradable polyester resin composition according to the examples can appropriately maintain their mechanical strength within the normal service period.

[0557] For example, the biodegradable polyester resin composition according to the examples may have an appropriate tensile strength, an appropriate elongation at break, and / or an appropriate hardness.

[0558] Also, the biodegradable polyester resin composition according to the examples may have a high content of aliphatic carboxylic acid or may have improved mechanical properties. Accordingly, the biodegradable polyester resin composition according to the examples may simultaneously have improved mechanical properties and appropriate biodegradability.

[0559] In the biodegradable polyester resin composition according to the examples, the initial tensile strength, the tensile strength after ultraviolet irradiation, the tensile strength reduction rate, the initial elongation at break, the elongation at break after ultraviolet irradiation, and the elongation at break reduction rate can be appropriately adjusted by the manufacturing process of the biodegradable polyester resin, the ratio of the number of the first block and the second block, the reinforcing material, the light stabilizer, and the elongation improver.

[0560] The biodegradable polyester resin composition according to the examples has a low tensile strength reduction rate from the initial stage of ultraviolet rays to 1 day. Films and the like produced from the biodegradable polyester resin composition according to the examples can be used for ordinary purposes such as packaging. At this time, when the biodegradable polyester resin composition according to the examples is exposed to ultraviolet rays, the initial tensile strength reduction rate is low. As a result, films and the like produced from the biodegradable polyester resin composition according to the examples have a low reduction in tensile strength due to ultraviolet exposure within the normal usage period.

[0561] As a result, molded articles produced from the biodegradable polyester resin composition according to the examples can appropriately maintain their mechanical strength within the normal usage period.

[0562] Also, when the biodegradable polyester resin composition according to the examples is exposed to ultraviolet rays for a long time, the tensile strength reduction rate may be high. For example, the biodegradable polyester resin composition according to the examples may have a tensile strength reduction rate of 67% or more 6 days after the initial stage of ultraviolet irradiation.

[0563] As a result, the biodegradable polyester resin composition according to the examples can be easily decomposed when exposed to sunlight for a long time after being discarded. Molded articles produced from the biodegradable polyester resin composition according to the examples can be easily decomposed not only by biodegradation but also by decomposition by sunlight. Also, molded articles produced from the biodegradable polyester resin composition according to the examples can be decomposed more efficiently in a natural state because decomposition by sunlight promotes biodegradation. Molded articles produced from the biodegradable polyester resin composition according to the examples can also be easily decomposed by ultraviolet rays and the like when discarded into the sea.

[0564] Therefore, the biodegradable polyester resin composition according to the examples can reduce the burden on the global environment, particularly reduce the pollution of the marine ecosystem.

[0565] The molded article produced by the biodegradable polyester resin composition according to the example can be efficiently decomposed at the time of disposal while maintaining the required mechanical properties within the actual usage period.

[0566] The above content will be further detailed by the following examples. However, the following examples are for illustrating the present invention, and the scope of the examples is not limited thereto.

[0567] <Manufacturing Example> Production of Pretreated Cellulose Nanocrystal Dry powder - shaped cellulose nanocrystal (NVC - 100, manufacturer: Celluforce) having a particle size of about 1 μm to about 50 μm was dispersed in water at 1 wt%, and then ultrasonic treatment was performed for 1 minute at an output of 20000 J / s using a tip - type ultrasonic disperser to produce pretreated nanocellulose.

[0568] Light stabilizer: SUNOVIN 904 (SUNSHOW) Chain extender: Hexamethylene diisocyanate Crystallinity regulator: Diisopropyl adipate (DPA), Tetrahydrofuran (THF) or Cyclopentanone (CPN)

[0569] <Example> Example 1 Production of Biodegradable Polyester Resin First stage: The stage of obtaining a slurry by pretreatment As shown in Table 1, the pre-treated nanocellulose, light stabilizer, diisopropyl adipate, 1,4-butanediol (1,4-BDO), and terephthalic acid (TPA) were mixed at a molar ratio of 1,4-BDO:TPA of 1.4:1 and 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) in a catalyst-free state. At this time, the D50 of the terephthalic acid (TPA) was 100 μm. The contents of the nanocellulose, the light stabilizer, and the elongation improver were in wt% based on the total raw materials charged.

[0570] Next, the mixture was stirred at 60 °C and 100 rpm for 1 hour for pretreatment to obtain a slurry without phase separation.

[0571] Step 2: Obtaining a prepolymer The slurry obtained in the first step was charged into a reactor through a supply line. After charging 250 ppm of tetrabutyl titanate (manufactured by Dupont, Tyzor TnBT), a titanium-based catalyst, a primary esterification reaction was carried out at 200 °C and normal pressure for about 1 hour and 30 minutes until 95% of the by-product water was discharged.

[0572] To the reaction product, 52 mol% of 1,4-butanediol (1,4-BDO) based on the total number of moles of diol, 40 mol% of adipic acid (AA) based on the total number of moles of dicarboxylic acid components, and 200 ppm of tetrabutyl titanate (manufactured by Dupont, Tyzor TnBT), a titanium-based catalyst, were added based on the total weight of diol, aromatic dicarboxylic acid, and aliphatic dicarboxylic acid. Then, a secondary esterification reaction was carried out at 210 °C and normal pressure for about 2 hours and 10 minutes until 95% of the by-product water was discharged to produce a prepolymer having a number average molecular weight of 5500 g / mol.

[0573] Step 3: Performing a polycondensation reaction To the prepolymer obtained in the second stage, 150 ppm of tetrabutyl titanate (manufactured by Dupont, Tyzor TnBT) as a titanium-based catalyst and 500 ppm of triethylene phosphate stabilizer were added based on the total weight of the diol, aromatic dicarboxylic acid, and aliphatic dicarboxylic acid, and it was 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. After cooling this to 5°C, it was cut with a pellet cutter to obtain biodegradable polyester resin pellets.

[0574] Examples 2 to 7 As shown in Table 1 below, the contents of adipic acid, dimethyl terephthalate, terephthalic acid, cellulose nanocrystal, light stabilizer, and additive are different. Also, as shown in Table 3, the process temperatures and times in the primary esterification reaction and the secondary esterification reaction are different. Except for the said contents and the said processes, other processes were carried out substantially referring to Example 1.

[0575] Examples 8 to 14 First stage: The stage of obtaining a slurry by pretreatment As shown in Table 1, the pretreated nanocellulose, diisopropyl adipate, tetrahydrofuran, cyclopentanone, 1,4-butanediol (1,4-BDO), and terephthalic acid (TPA) were mixed at a molar ratio of (1,4-BDO:TPA) 1.2:1, and without a catalyst, it was put 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.

[0576] Next, the mixture was stirred at 60°C and 100 rpm for 1 hour for pretreatment to obtain a slurry without phase separation.

[0577] In Table 2 above, the contents of the pretreated nanocellulose, the diisopropyl adipate, the tetrahydrofuran, and the cyclopentanone were in ppm based on the total weight of the raw materials input.

[0578] As shown in Tables 2 and 4 below, the compositions of the reactants and the process conditions in the primary esterification reaction and the secondary esterification reaction were different. Except for the said content and the said process, other processes were carried out with substantial reference to Example 1.

[0579] Comparative Examples 1 to 5 As shown in Tables 1 and 2 below, the contents of adipic acid, dimethyl terephthalate, terephthalic acid, cellulose nanocrystal, light stabilizer, and additive were different. Also, as shown in Tables 3 and 4, the process temperatures and times in the primary esterification reaction and the secondary esterification reaction were different. Also, the said pretreatment process was not applied and the esterification reaction was carried out. Except for the said content and the said process, other processes were carried out with substantial reference to Example 1.

[0580] 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 about 7 g of the produced polyester resin pellets were put into the stainless steel (SUS) frame (area 12 cm × 12 cm), and then covered with the other Teflon sheet and positioned at the center of a hot press (manufacturer: Wisrap, 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 to produce a biodegradable polyester sheet having an area of about 10 cm × 10 cm and a thickness of about 300 μm.

[0581] 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 machine (Blown Film Extrusion Line, manufacturer: Yuzhin Engineering) to produce a biodegradable polyester film with a thickness of 50 μm.

[0582]

Table 1

[0583]

Table 2

[0584]

Table 3

[0585]

Table 4

[0586] <Evaluation Example> Evaluation Example 1: Average particle size (D50) and standard deviation <Average particle size (D50) and standard deviation of aromatic dicarboxylic acid> Using a particle size analyzer Microtrac S3500 (Microtrac Inc) in the particle size distribution (PSD), the average particle size (D50) and standard deviation (SD, Standard Deviation) of the aromatic dicarboxylic acid (TPA or DMT) were determined under the following conditions:

[0587] Operating 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.

[0588] The standard deviation means the square root of the variance and can be calculated using software.

[0589] <Particle size of nanocellulose> For nanocellulose, the particle size and particle size deviation were measured by the principle of dynamic light scattering (DLS) using a Zetasizer Nano ZS (manufacturer: Marven) 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.

[0590] Evaluation Example 2: Tensile strength and elongation at break The polyester sheets with a thickness of about 300 μm produced in the examples and comparative examples were cut into specimens from the biodegradable polyester sheets produced in the examples or comparative examples based on ASTM D638 Type V, and then experimented at a tensile speed of 100 mm / min using a universal testing machine (UTM, model name 4206 - 001) from INSTRON. After that, the tensile strength (kgf / mm 2 = 9.8 Mpa) and elongation at break were measured by the program installed in the equipment.

[0591] Evaluation Example 3: QUV test The polyester sheet (thickness about 300 μm) was continuously irradiated with ultraviolet rays from a UVA340 ultraviolet lamp at a strength of about 0.75 W / m 2 . After a certain period of time elapsed, the tensile strength and elongation at break were measured.

[0592] Also, the polyester sheet (thickness about 300 μm) was continuously irradiated with ultraviolet rays from the UVA340 ultraviolet lamp at a strength of about 0.35 W / m 2 . After a certain period of time elapsed, the tensile strength and elongation at break were measured.

[0593] Evaluation Example 4: Rate of decrease in molecular weight Flakes (approx. 3 cm × 3 cm) made from the biodegradable polyester resin sheets produced in the examples and comparative examples were mixed with compost (manufacturer: Taeheung F&G, product name: Earth Raw Soil (by-product fertilizer grade 1 compost), compost composition: 40 wt% pig manure, 15 wt% chicken manure, 37 wt% large sawdust, 5 wt% zeolite, 3 wt% microbial preparation), 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.

[0594] The GPC equipment and measurement conditions are as follows.

[0595] Sample pretreatment: Dissolve 0.035 mg of PBAT chip in 1.5 ml of THF Measuring device: waters e2695 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

[0596] [Formula 3] JPEG2025522289000034.jpg12153

[0597] Evaluation Example 5: Degree of biodegradability For the samples produced in the above Examples and Comparative Examples, the amount of carbon dioxide generated was measured and the biodegradability was measured in accordance with KS M3100-1. Specifically, an inoculum source container containing only the compost produced in a compost plant was prepared, and a test container was prepared in which the film was added to the compost in an amount of 5% by weight of the dry weight of the compost. Then, the mixture was 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, and the carbon dioxide generated in each container was collected and titrated with an aqueous solution of phenolphthalein to measure the amount of carbon dioxide generated in each container. The biodegradability was calculated by Formula 3 using the measured amount of carbon dioxide generated.

[0598] [Formula 4] JPEG2025522289000035.jpg12165

[0599] Evaluation Example 6: Nuclear Magnetic Resonance Spectroscopy About 5 mg of a sample was prepared from the biodegradable polyester resin compositions of the Examples and Comparative Examples, and the sample was dissolved in CDCl3. Then, the solution was subjected to 1 1H-NMR analysis by a nuclear magnetic resonance (NMR) apparatus (JEOL 500 MHz, 90° pulse) at room temperature. Then, in the obtained NMR data, the peaks of the terephthalic acid, the adipic acid, and the 1,4-butanediol were integrated.

[0600] Apparatus: Manufactured by JEOL, JNM-LA3000 Pulse: About 90° Repetition time: About 4 sec Number of integrations: Measured 8 times Temperature: About 25 °C

[0601] Evaluation Example 7: Tensile Strength and Elongation at Break The polyester sheets with a thickness of about 300 μm produced in the examples and comparative examples were cut into test pieces from the biodegradable polyester sheets produced in the examples or comparative examples based on ASTM D638 Type V. After that, using a universal testing machine (UTM, model name 4206 - 001) from INSTRON, the experiment was conducted at a tensile speed of 100 mm / min, and then the tensile strength (kgf / geta = 9.8 Mpa) and elongation at break were measured by a program installed in the equipment.

[0602] Evaluation Example 8: Shore D Hardness The hardness of the polyester block was measured by a shore hardness measuring equipment (SAUTER (registered trademark) Digital Professional Shore Hardness Tester). Then, the polyester block was cut into a size of about 3 cm × 3 cm, and the hardness of the polyester block was measured by the shore hardness measuring equipment.

[0603] Evaluation Example 9: Crystallinity Using a differential scanning calorimeter (DSC, Q500 from TA instrument), 4 mg of the sample was sampled into an Al pan, heated from 40 °C to 180 °C at a rate of 10 °C / min, then isothermal for 5 minutes to perform the primary heat history removal process. It was frozen from 180 °C to -50 °C at a rate of 10 °C / min and isothermal for 5 minutes to perform the cooling process. Then, while heating from -50 °C to 180 °C at a heating rate of 10 °C / min, the heat quantity change of heat absorption and heat release of the biodegradable polyester resin was measured. At this time, as shown in Equation 12, the measured melting enthalpy was divided by 114 J / g and multiplied by 100 to measure the crystallinity.

[0604] As shown in Table 5 below, the tensile strength at the initial stage and after a certain number of days of the QUV test with a strength of about 0.75 W / m 2 was measured.

[0605]

Table 5

[0606] As shown in Table 6 below, the tensile strength reduction rate after a certain number of days has elapsed in a QUV test with a strength of about 0.75 W / m 2 has been derived.

[0607]

Table 6

[0608] As shown in Table 7 below, the elongation at break at the initial stage and after a certain number of days have elapsed in a QUV test with a strength of about 0.75 W / m 2 has been measured.

[0609]

Table 7

[0610] As shown in Table 8 below, the reduction rate of the elongation at break after a certain number of days have elapsed in a QUV test with a strength of about 0.35 W / m 2 has been derived.

[0611]

Table 8

[0612] As shown in Table 9 below, the tensile strength at the initial stage and after a certain number of days have elapsed in a QUV test with a strength of about 0.35 W / m 2 has been measured.

[0613]

Table 9

[0614] As shown in Table 10 below, the tensile strength reduction rate after a certain number of days have elapsed in a QUV test with a strength of about 0.35 W / m 2 has been derived.

[0615]

Table 10

[0616] As shown in Table 11 below, the elongation at break at the initial stage and after a certain number of days has elapsed is measured in a QUV test with a strength of about 0.35 W / m 2 2

[0617]

Table 11

[0618] As shown in Table 12 below, the rate of decrease in the elongation at break after a certain number of days has elapsed is derived in a QUV test with a strength of about 0.35 W / m 2 2

[0619]

Table 12

[0620] As shown in Table 13 below, the rate of decrease in molecular weight and biodegradability are derived

[0621]

Table 13

[0622] As described in Table 14 below, the biodegradability in the examples and comparative examples is measured

[0623]

Table 14

[0624] As described in Table 15 below, the degree of hydrolysis is measured

[0625]

Table 15

[0626] As described in Table 16 below, 1 The peaks and peak areas by H-NMR have been measured.

[0627]

Table 16

[0628] As described in Table 17 below, the degree of alternation, tensile strength, elongation at break, degree of crystallinity, and hardness have been derived.

[0629]

Table 17

[0630] As shown in Tables 5 to 13, the biodegradable polyester resin composition according to the examples had a low tensile strength reduction rate and a low elongation at break reduction rate after 1 day of ultraviolet irradiation. Further, the biodegradable polyester resin composition according to the examples had a high tensile strength reduction rate and a high elongation at break reduction rate after 7 days or 9 days of the ultraviolet irradiation.

[0631] Further, the biodegradable polyester resin composition according to the examples had a high molecular weight reduction rate and a degree of biodegradability.

[0632] Further, as described in Tables 14 to 17 above, the biodegradable polyester resin composition according to the examples may have an appropriate initial degree of hydrolysis and a high later degree of hydrolysis. Also, the biodegradable polyester resin composition according to the examples may have an appropriate mechanical strength and a high degree of biodegradability.

Industrial Applicability

[0633] The examples relate to a biodegradable resin composition, a film, and a molded article.

Claims

1. A biodegradable molded article comprising a polyester resin containing a diol, an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid. When irradiated with ultraviolet rays from a UVA340 ultraviolet lamp at a strength of 0.75 W / m ２ , the tensile strength reduction rate from the initial stage to 1 day of the ultraviolet irradiation is 5% to 40% based on a thickness of 300 μm. A biodegradable molded article.

2. A biodegradable molded article according to Claim 1, further comprising nanocellulose containing a metal, having an average diameter of 0.5 nm to 10 nm and an average length of 20 nm to 300 nm. A biodegradable molded article according to Claim 1.

3. A biodegradable molded article according to Claim 1, further comprising a light stabilizer having a weight average molecular weight of 1,800 g / mol to 5,000 g / mol. A biodegradable molded article according to Claim 1.

4. A biodegradable polyester resin composition comprising a polyester resin containing a diol, an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid, wherein the tensile strength reduction rate is measured by the following method: When irradiated continuously with ultraviolet rays from a UVA340 ultraviolet lamp at a strength of 0.75 W / m ２ the tensile strength reduction rate from the initial stage to 1 day of the ultraviolet irradiation is 5% to 40%, [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 tensile strength reduction rate is a value obtained by dividing the difference between the initial tensile strength of the polyester sheet and the tensile strength of the polyester sheet after ultraviolet irradiation by the initial tensile strength.

5. The biodegradable polyester resin composition according to Claim 4, wherein the tensile strength reduction rate from the initial stage to 3 days of the ultraviolet irradiation is 40% to 65%. A biodegradable polyester resin composition according to Claim 4.

6. The biodegradable polyester resin composition according to Claim 4, wherein the tensile strength reduction rate from the initial stage to 6 days of the ultraviolet irradiation is 67% or more. A biodegradable polyester resin composition according to Claim 4.

7. A biodegradable polyester resin composition according to Claim 4. When irradiated with the ultraviolet light at a strength of 0.35 W / m ２ the tensile strength reduction rate from the initial stage to 1 day of the ultraviolet irradiation is 1% to 20%.

8. A biodegradable polyester resin composition according to Claim 7. When irradiated with the ultraviolet light at a strength of 0.35 W / m ２ the tensile strength reduction rate from the initial stage to 9 days of the ultraviolet irradiation is 65% or more.

9. The biodegradable polyester resin composition according to Claim 4, wherein the initial tensile strength is 40 MPa to 60 MPa and the tensile strength after 7 days is 1 MPa to 15 MPa. A biodegradable polyester resin composition according to Claim 4.

10. The biodegradable polyester resin composition according to Claim 4, wherein the elongation at break reduction rate from the initial stage to 1 day of the ultraviolet irradiation is 5% to 40%, and the elongation at break reduction rate from the initial stage to 7 days of the ultraviolet irradiation is 80% or more. A biodegradable polyester resin composition according to Claim 4.

11. The biodegradable polyester resin composition according to Claim 4, wherein the elongation at break reduction rate from the initial stage to 9 days of the ultraviolet irradiation is 80% or more. When the ultraviolet ray is irradiated at a strength of 0.35 W / m ２ the reduction rate of the elongation at break from the initial stage to 1 day of the ultraviolet irradiation is 1% to 20%, A biodegradable polyester resin composition according to Claim 4.

12. A biodegradable polyester resin composition comprising a polyester resin containing a diol, an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid, and a crystallinity regulator, wherein the crystallinity is 10% to 15%. A polyester resin containing a diol, an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid, And a crystallinity regulator, The crystallinity is 10% to 15%, A biodegradable polyester resin composition.

13. The degree of crystallinity regulator contains diisopropyl adipate, The biodegradable polyester resin composition according to claim 12.

14. The diisopropyl adipate is contained in a content of 10 ppm to 10,000 ppm based on the weight of the polyester resin, The biodegradable polyester resin composition according to claim 13.

15. The tensile strength measured by the following measurement method is 40 MPa to 60 MPa, The biodegradable polyester resin composition according to claim 13. [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, and the tensile strength of the polyester sheet is measured.

16. The elongation at break measured by the following measurement method is 800% to 1200%, The biodegradable polyester resin composition according to claim 15. [Measurement method] The elongation at break of the polyester sheet is measured.

17. The Shore D hardness measured by the following measurement method is 30 to 45, The biodegradable polyester resin composition according to claim 16. [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 block having a thickness of 2.5 mm, and the Shore D hardness of the polyester block is measured.

18. The degree of crystallinity regulator contains tetrahydrofuran, The biodegradable polyester resin composition according to claim 13.

19. The weight ratio of the diisopropyl adipate and the tetrahydrofuran is 1:1 to 1:5, The biodegradable polyester resin composition according to claim 18.

20. The ratio of alternation of the polyester resin is 0.37 to 0.59, The ratio of alternation is the ratio of the diol that binds between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid among the diols, The biodegradable polyester resin composition according to claim 12.

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