Biodegradable polyester resin composition, biodegradable polyester film containing the same, and biodegradable molded article containing the same

Abstract

The example provides a biodegradable polyester resin composition containing a polyester resin including a diol, an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid, wherein the alternation ratio of the polyester resin is 0.3 to 0.7, and the alternation ratio is the ratio of the diol that binds between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid among the diols.

Description

Technical Field

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

Background Art

[0002] In recent years, as the concern about environmental problems has increased, solutions to the treatment problems of various daily necessities, especially disposable products, have been demanded. Specifically, polymer materials are inexpensive and have excellent properties such as processability, and are widely used to manufacture 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 takes hundreds of years for some types to be completely decomposed naturally, which has the disadvantage.

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

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

Summary of the Invention

Problems to be Solved by the Invention

[0005] The examples seek to provide a biodegradable polyester resin composition having improved biodegradability, hydrolysis resistance, and improved mechanical properties, a biodegradable polyester film containing the same, and a biodegradable molded article containing the same.

Means for Solving the Problems

[0006] 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, the alternation ratio of the polyester resin is 0.37 to 0.59, and the alternation ratio is the ratio of the diol that binds between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid among the diols.

[0007] In the biodegradable polyester resin composition according to one example, the alternation ratio may be 0.4 to 0.56.

[0008] In the biodegradable polyester resin composition according to one example, the alternation ratio may be 0.45 to 0.53.

[0009] In the biodegradable polyester resin composition according to one example, the diol may contain 1,4-butanediol, the aromatic dicarboxylic acid may contain terephthalic acid or dimethyl terephthalate, and the aliphatic dicarboxylic acid may contain adipic acid.

[0010] In the biodegradable polyester resin composition according to one example, the ratio of the hard segment is about 0.2 to about 0.3, and the ratio of the hard segment may be the ratio of the diol that binds between the aromatic dicarboxylic acid and the aromatic dicarboxylic acid among the diols.

[0011] In the biodegradable polyester resin composition according to one example, the ratio of the soft segment is about 0.21 to about 0.31, and the ratio of the soft segment may be the ratio of the diol that binds between the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid among the diols.

[0012] In the biodegradable polyester resin composition according to one example, the ratio of the soft segment may be even larger than the ratio of the hard segment.

[0013] In a biodegradable polyester resin composition according to an embodiment, the biodegradation degree after 9 weeks is 85% or more, and the biodegradation degree after 9 weeks can be measured by the following measurement method.

[0014] [Measurement method] The biodegradation degree after 9 weeks is the reduction rate of the molecular weight of the biodegradable polyester resin composition with respect to the initial value when the biodegradable polyester resin composition is placed under composting conditions, at a temperature of 60 °C and a humidity of 90% for 9 weeks.

[0015] In a biodegradable polyester resin composition according to an embodiment, the biodegradation degree per aliphatic carboxylic acid after 9 weeks is 1.7 or more, and the biodegradation degree per aliphatic carboxylic acid after 9 weeks may be a value obtained by dividing the biodegradation degree after 9 weeks by the molar percentage of the aliphatic carboxylic acid in the total dicarboxylic acids.

[0016] The biodegradable polyester resin composition according to the embodiment contains a polyester resin containing a diol, an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid, the ratio of the hard segment of the polyester resin is 0.2 to 0.3, and the ratio of the hard segment is the ratio of the diol that binds between the aromatic dicarboxylic acid and the aromatic aliphatic carboxylic acid among the diols.

[0017] In a biodegradable polyester resin composition according to an embodiment, the ratio of the hard segment may be 0.21 to 0.28.

[0018] In a biodegradable polyester resin composition according to an embodiment, the ratio of the hard segment may be 0.22 to 0.27.

[0019] In a biodegradable polyester resin composition according to an embodiment, the tensile strength measured by the following measurement method may be 40 MPa to 60 MPa.

[0020] [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.

[0021] In the biodegradable polyester resin composition according to one embodiment, the elongation at break of the polyester sheet may be about 800% to about 1100%.

[0022] The biodegradable molded article according to the embodiment contains a polyester resin containing a diol, an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid, the crosslinking ratio of the polyester resin is 0.37 to 0.59, and the crosslinking ratio is the ratio of the diol that binds between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid among the diols.

[0023] In the biodegradable molded article according to one embodiment, the ratio of the hard segment may be about 0.2 to about 0.3, and the ratio of the hard segment is the ratio of the diol that binds between the aromatic dicarboxylic acid and the aromatic dicarboxylic acid among the diols.

[0024] In the biodegradable molded article according to one embodiment, the ratio of the soft segment may be about 0.21 to about 0.31, and 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.

[0025] In the biodegradable molded article according to one embodiment, the tensile strength may be 40 MPa to 60 MPa.

[0026] In the biodegradable molded article according to one embodiment, the elongation at break may be about 800% to about 1100%.

[0027] In the biodegradable molded article according to one embodiment, the diol includes 1,4-butanediol, the aromatic dicarboxylic acid includes terephthalic acid or dimethyl terephthalate, and the aliphatic dicarboxylic acid may include adipic acid.

Advantages of the Invention

[0028] The biodegradable polyester resin composition according to the embodiment includes a polyester resin having an appropriate degree of alternation. The content of the diol bonded between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid may be appropriate.

[0029] Thereby, the biodegradable polyester resin may have a structure in which the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid are appropriately arranged alternately. Thereby, the biodegradable polyester resin may have improved crystalline properties, and the biodegradable polyester resin composition according to the embodiment may have improved thermal and mechanical properties.

[0030] Further, since the biodegradable polyester resin has a structure in which the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid are appropriately arranged alternately, the aromatic and aliphatic groups can be appropriately cross-linked in the molecule of the biodegradable polyester resin. Thereby, the biodegradable polyester resin composition according to the embodiment may simultaneously have an appropriate degree of hydrolysis and an improved degree of biodegradability.

[0031] Further, since the biodegradable polyester resin has the above molecular structure, the biodegradable polyester resin composition according to the embodiment may have a degree of biodegradability per unit content of a high aliphatic dicarboxylic acid.

[0032] The biodegradable polyester resin composition according to the embodiment includes a polyester resin having an appropriate proportion of hard segments. The content of the diol bonded between the aromatic dicarboxylic acid and the aromatic dicarboxylic acid may be appropriate.

[0033] As a result, the biodegradable polyester resin may appropriately contain the aromatic dicarboxylic acid and the bonding structure in which the aromatic dicarboxylic acid is bonded to the diol. As a result, the biodegradable polyester resin may have improved crystalline properties, and the biodegradable polyester resin composition according to the examples may have improved thermal and mechanical properties.

[0034] In particular, since the biodegradable polyester resin has a proportion of hard segments within the above range, the biodegradable polyester resin composition according to the examples may appropriately have a high tensile strength and elongation at break.

[0035] Further, since the biodegradable polyester resin has the above molecular structure, it may have appropriate moisture resistance and solvent resistance. As a result, the biodegradable polyester resin composition according to the examples may have improved printability.

[0036] Therefore, the biodegradable polyester resin composition according to the examples may have improved physical properties during the actual use period and may be easily biodegradable after use.

[0037] The biodegradable polyester resin composition according to the examples can be efficiently applied to packaging films and the like. That is, the film produced from the biodegradable polyester resin composition according to the examples can be used for normal applications such as packaging. At this time, the biodegradable polyester resin composition according to the examples may have a low degree of hydrolysis initially, and within the normal use period of the user, the biodegradable polyester film can maintain mechanical and chemical properties to a certain extent or more.

[0038] At the same time, since the biodegradable polyester resin composition according to the examples has a high degree of biodegradability, the film produced from the biodegradable polyester resin composition according to the examples may be easily decomposed when discarded after use.

Brief Description of the Drawings

[0039]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0040] Hereinafter, the invention will be described in detail with reference to implementation examples. The implementation examples are not limited to the content disclosed below, and can be modified into various forms as long as the gist of the invention remains unchanged.

[0041] In this specification, when a certain part “includes” a component, unless otherwise stated, it does not exclude other components, but may further include other components.

[0042] Also, all numerical ranges indicating physical property values, dimensions, etc. of the components described in this specification should be understood to be modified by the term “about” unless otherwise specified.

[0043] Terms such as first, second, primary, secondary, etc. in this specification are used to describe various components, and the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

[0044] In the description according to this embodiment, ppm as a unit of content may be based on the total mass.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] The diol may contain 1,4-butanediol or a derivative thereof.

[0052] 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.

[0053] 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.

[0054] The aromatic dicarboxylic acid may contain terephthalic acid, dimethyl terephthalate, or derivatives thereof.

[0055] 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.

[0056] The aliphatic dicarboxylic acid may be at least one selected from the group consisting of adipic acid, succinic acid, sebacic acid, or derivatives thereof.

[0057] The aliphatic dicarboxylic acid may contain adipic acid or a derivative thereof.

[0058] In the biodegradable polyester resin, the molar ratio of the total diol residues including the diol to the total dicarboxylic acid residues including 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] Further, 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.

[0064] 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.

[0065] 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.

[0066] In the biodegradable polyester resin, the ratio (X / Y) of the number (X) of the first blocks to the number (Y) of the second blocks may be from about 0.5 to about 1.5. In the biodegradable polyester resin, the ratio (X / Y) of the number (X) of the first blocks to the number (Y) of the second blocks may be from about 0.6 to about 1.4. In the biodegradable polyester resin, the ratio (X / Y) of the number (X) of the first blocks to the number (Y) of the second blocks may be from about 0.7 to about 1.3. In the biodegradable polyester resin, the ratio (X / Y) of the number (X) of the first blocks to the number (Y) of the second blocks may be from about 0.75 to about 1.2. Also, in the biodegradable polyester resin, the ratio (X / Y) of the number (X) of the first blocks to the number (Y) of the second blocks may be 0.8 to 1. The number of the first blocks may be even smaller than the number of the second blocks.

[0067] 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.

[0068] The number of the first blocks varies depending on the content of the aromatic dicarboxylic acid, the molecular weight of the biodegradable polyester resin, and the crosslinking ratio described below. That is, as the molar ratio of the aromatic dicarboxylic acid increases, as the molecular weight of the biodegradable polyester resin increases, and as the crosslinking degree described below increases, the number of the first blocks can be increased.

[0069] The number of the second blocks may be from about 30 to about 300. The number of the second blocks may be from about 40 to about 250. The number of the second blocks may be from about 50 to about 220. The number of the second blocks may be from about 60 to about 200. The number of the second blocks may be from about 70 to about 200. The number of the second blocks may be from about 75 to about 200.

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

[0071] 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. Thereby, 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.

[0072] The first block may be represented by Chemical Formula 1 below.

[0073]

Chemical Formula

[0074] 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.

[0075] R1 is a substituted or unsubstituted phenylene group, and R2 may be a butylene group.

[0076] The second block may be represented by Chemical Formula 2 below.

[0077]

Chemical Formula

[0078] Here, R3 and R4 are each independently a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, and n may be 1 to 20.

[0079] R3 and R4 may be butylene groups.

[0080] 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.

[0081]

Chemical Formula

[0082] Here, R1 is a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, R2 is a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, and m may be 1 to 20. Also, R3 and R4 are each independently a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, and n may be 1 to 20.

[0083] The diol residue includes a residue of 1,4-butanediol or a derivative thereof, the aromatic dicarboxylic acid residue includes a residue of terephthalic acid or a derivative thereof, and the aliphatic dicarboxylic acid residue may include a residue of adipic acid or a derivative thereof.

[0084] For example, the biodegradable polyester resin may include a first block containing a residue of 1,4-butanediol or a derivative thereof and a residue of terephthalic acid or a derivative thereof.

[0085] Alternatively, the biodegradable polyester resin may include a first block containing a residue of 1,4-butanediol or a derivative thereof and a residue of dimethyl terephthalate or a derivative thereof.

[0086] The biodegradable polyester resin may include a second block containing a residue of 1,4-butanediol or a derivative thereof and a residue of adipic acid or a derivative thereof.

[0087] Alternatively, the biodegradable polyester resin may include a second block containing a residue of 1,4-butanediol or a derivative thereof and a residue of succinic acid or a derivative thereof.

[0088] The biodegradable polyester resin according to an embodiment of the present invention may include a first block containing a residue of 1,4-butanediol or a derivative thereof and a residue of terephthalic acid or a derivative thereof, and a second block containing a residue of 1,4-butanediol or a derivative thereof and a residue of adipic acid or a derivative thereof.

[0089] The first block may be represented by Chemical Formula 4 below, and the second block may be represented by Chemical Formula 5 below.

[0090]

Chemical Formula

[0091] Here, the m may be from 1 to 20.

[0092]

Chemical formula

[0093] Here, the n may be from 1 to 20.

[0094] The biodegradable polyester resin may be the one represented by the following Chemical formula 6.

[0095]

Chemical formula

[0096] Here, the m is from 1 to 20, and the n may be from 1 to 20.

[0097] 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 product excellent in biodegradability and hydrolysis resistance and having improved physical properties.

[0098] Further, when the biodegradable polyester resin contains the first block and the second block within the above range, the biodegradable polyester resin composition according to the examples may have appropriate mechanical properties and appropriate UV resistance properties.

[0099] Since the first block and the second block have the above characteristics, the mechanical properties of the biodegradable polyester resin composition according to the examples can be improved.

[0100] Since the first block and the second block have the above characteristics, the biodegradable polyester resin composition according to the examples may have appropriate UV resistance properties.

[0101] 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.

[0102] 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 hydrolysis rate.

[0103] The biodegradable polyester resin may include the following bonding structures 1 to 3.

[0104] [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-

[0105] 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 be directly esterified to the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid.

[0106] 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 be directly esterified to the aromatic dicarboxylic acid and the aromatic dicarboxylic acid between the aromatic dicarboxylic acid and the aromatic dicarboxylic acid.

[0107] Also, the diol contained in the above bonding structure 3 bonds to the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid between the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid. The diol contained in the above bonding structure 3 may be directly esterified between the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid to the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid.

[0108] In the biodegradable polyester resin, the above bonding structure 1 may be represented by the following Chemical Formula 7.

[0109]

Chemical Formula

[0110] 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.

[0111] In the biodegradable polyester resin, the above bonding structure 2 may be represented by the following Chemical Formula 8.

[0112]

Chemical Formula

[0113] 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.

[0114] In the biodegradable polyester resin, the above bonding structure 3 may be represented by the following Chemical Formula 9.

[0115]

Chemical Formula

[0116] 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.

[0117] Further, the above bonding structure 1 may be represented by Chemical Formula 10 below.

[0118]

Chemical Formula

[0119] Further, the above bonding structure 2 may be represented by Chemical Formula 11 below.

[0120]

Chemical Formula

[0121] Further, the above bonding structure 3 may be represented by Chemical Formula 12 below.

[0122]

Chemical Formula

[0123] The biodegradable polyester resin has an alternating ratio.

[0124] 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.

[0125] 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.

[0126] The crosslinking ratio can be calculated by the following formula 1.

[0127] [Formula 1] JPEG2025517983000014.jpg20128

[0128] 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.

[0129] 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.

[0130] Also, the biodegradable polyester resin contains a ratio of hard segments.

[0131] 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 between the diols.

[0132] The ratio of the hard segments may be the molar ratio of the diols contained in the above bonding structure 2 among all the 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.

[0133] The ratio of the hard segment may be represented by the following Mathematical Formula 2.

[0134] [Mathematical Formula 2] JPEG2025517983000015.jpg20141

[0135] Here, the DM1 is the molar ratio of the diol contained in the above bonding structure 1, the DM2 is the molar ratio of the diol contained in the above bonding structure 2, and the DM3 is the molar ratio of the diol contained in the above bonding structure 3.

[0136] 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.

[0137] In addition, the biodegradable polyester resin composition contains a soft segment.

[0138] 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 above diols.

[0139] The ratio of the soft segment may be the molar ratio of the diol contained in the above bonding structure 3 among the total diols. The ratio of the soft segment may be a value obtained by dividing the number of moles of the diol contained in the above bonding structure 3 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.

[0140] The ratio of the soft segment may be represented by the following Mathematical Formula 3.

[0141] [Mathematical Formula 3] JPEG2025517983000016.jpg20140

[0142] 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.

[0143] The proportion of the soft segment may be about 0.16 to about 0.36. The proportion of the soft segment may be about 0.21 to about 0.31. The proportion of the soft segment may be about 0.22 to about 0.30. The proportion of the hard segment may be about 0.23 to about 0.29.

[0144] The proportion of the soft segment may be even larger than the proportion of the hard segment.

[0145] 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.

[0146] The proportion of the crosslinking, the proportion of the hard segment, and the proportion of the soft segment can be measured by nuclear magnetic resonance spectroscopy. The biodegradable polyester resin composition according to the example 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.

[0147] 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.

[0148] 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 bonding structure 1, peaks derived from the diol of the above bonding structure 2, and peaks derived from the above bonding structure 3 at about 3.5 ppm to about 4.6 ppm.

[0149] The first peak, the second peak, the third peak, and the fourth peak may be defined in the order of decreasing ppm in the range of about 3.5 ppm to about 4.6 ppm. Further, based on the ppm of the ninth peak, the first peak, the second peak, the third peak, and the fourth peak may be defined in the order of decreasing ppm in the range of about -3.4 ppm to about -4.3 ppm. 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.

[0150] In addition, the analysis of the biodegradable polyester resin by the nuclear magnetic resonance spectroscopy may also include peaks derived from the diol of the above bonding structure 1, peaks derived from the diol of the above bonding structure 2, and peaks derived from the above bonding structure 3 at about 1.0 ppm to about 2.5 ppm.

[0151] 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. Based on the ppm of the 9th 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 -6.0 ppm to about -6.7 ppm in descending order of ppm from high to low. At this time, the 5th peak may be derived from the diol contained in the 2nd linking unit, the 6th peak and the 7th peak may be derived from the diol contained in the 1st linking unit, and the 8th peak may be derived from the diol contained in the 3rd linking unit.

[0152] 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.

[0153] 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.

[0154] 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.

[0155] 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.

[0156] Further, 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 set to 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.

[0157] The ratio of the alternation can be derived from the following Equation 4 or Equation 5.

[0158] [Equation 4] JPEG2025517983000017.jpg19128

[0159] Here, PA1 is the area of the first peak, PA2 is the area of the second peak, PA3 is the area of the third peak, and PA4 is the area of the fourth peak.

[0160] [Equation 5] JPEG2025517983000018.jpg19128

[0161] Here, PA5 is the area of the fifth peak, PA6 is the area of the sixth peak, PA7 is the area of the seventh peak, and PA8 is the area of the eighth peak.

[0162] The ratio of the hard segment can be derived from the following Equation 6 or the following Equation 7.

[0163] [Equation 6] JPEG2025517983000019.jpg20147

[0164] 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.

[0165] [Equation 7] JPEG2025517983000020.jpg20147

[0166] 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.

[0167] The ratio of the soft segment can be derived from the following Equation 8 or Equation 9.

[0168] [Equation 8] JPEG2025517983000021.jpg20145

[0169] 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.

[0170] [Equation 9] JPEG2025517983000022.jpg20145

[0171] 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.

[0172] The area of the first peak may be from about 0.35 to about 0.6. The area of the first peak may be from about 0.4 to about 0.55. The area of the first peak may be from about 0.43 to about 0.5. The area of the first peak may be from about 0.43 to about 0.52. The area of the first peak may be from about 0.45 to about 0.49.

[0173] The area of the second peak may be from about 0.37 to about 0.57. The area of the second peak may be from about 0.41 to about 0.54. The area of the second peak may be from about 0.45 to about 0.53. The area of the second peak may be from about 0.45 to about 0.55. The area of the second peak may be from about 0.47 to about 0.53.

[0174] 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.

[0175] The area of the fourth peak may be from 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.

[0176] 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.

[0177] 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.

[0178] 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.

[0179] 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.

[0180] 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.

[0181] 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.

[0182] Also, the sum of the area of the first peak, the area of the second peak, the area of the third peak, and the area of the fourth peak may be from about 1.49 to about 2.44. The sum of the area of the first peak, the area of the second peak, the area of the third peak, and the area of the fourth peak may be from about 1.81 to about 2.16. The sum of the area of the first peak, the area of the second peak, the area of the third peak, and the area of the fourth peak may be from about 1.9 to about 2.2. The sum of the area of the first peak, the area of the second peak, the area of the third peak, and the area of the fourth peak may be from about 1.95 to about 2.1. Here, the sum of the area of the first peak, the area of the second peak, the area of the third peak, and the area of the fourth peak may mean the sum of the number of total ester bonds based on the number of terephthalic acid molecules.

[0183] 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 mean the degree of elongation of the molecular bonds of the biodegradable polyester resin.

[0184] 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 mean the ratio of the soft segment to the hard segment in 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 the biodegradable polyester resin may have soft characteristics.

[0185] 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.

[0186] 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.

[0187] 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.

[0188] 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.

[0189] 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.

[0190] 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.

[0191] Since the biodegradable polyester resin has the molecular structure as described above, the biodegradable polyester resin composition according to the examples can more advantageously provide a biodegradable polyester sheet, film or molded article having excellent biodegradability and hydrolysis resistance and improved physical properties.

[0192] 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 properties.

[0193] 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.

[0194] 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 properties.

[0195] 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.

[0196] Since the biodegradable polyester resin has the above molecular structure, the biodegradable polyester resin composition according to the examples may have an appropriate hydrolysis rate.

[0197] The biodegradable polyester resin may further contain a branching agent. The branching agent may contain a trihydric or higher alcohol and / or a trihydric or higher carboxylic acid. 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.

[0198] The trihydric or higher alcohol may be selected from at least one or more of the group consisting of glycerol, pentaerythritol, or trimethylolpropane.

[0199] The above trivalent or higher carboxylic acid may be at least one selected from the group consisting of methane tricarboxylic acid, ethanetricarboxylic acid, citric acid, benzene-1,3,5-tricarboxylic acid, 5-sulfo-1,2,4-benzenetricarboxylic acid, ethane-1,1,2,2-tetracarboxylic acid, propane-1,1,2,3-tetracarboxylic acid, butane-1,2,3,4-tetracarboxylic acid, cyclopentane-1,2,3,4-tetracarboxylic acid, or benzene-1,2,4,5-tetracarboxylic acid.

[0200] 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 whole 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 whole 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 whole biodegradable polyester resin.

[0201] Since the biodegradable polyester resin contains the branching agent within the above range, the biodegradable polyester resin composition according to the examples may have appropriate mechanical properties and appropriate biodegradability.

[0202] The biodegradable polyester resin composition according to the embodiment may contain the biodegradable resin in a content of about 30 wt% or more based on the weight of the entire composition. The biodegradable polyester resin composition according to the embodiment may contain the biodegradable resin in a content of about 50 wt% or more based on the weight of the entire composition. The biodegradable polyester resin composition according to the embodiment may contain the biodegradable resin in a content of about 70 wt% or more based on the weight of the entire composition. The biodegradable polyester resin composition according to the embodiment may contain the biodegradable resin in a content of about 80 wt% or more based on the weight of the entire composition. The biodegradable polyester resin composition according to the embodiment may contain the biodegradable resin in a content of about 90 wt% or more based on the weight of the entire composition. The biodegradable polyester resin composition according to the embodiment may contain the biodegradable resin in a content of about 95 wt% or more based on the weight of the entire composition. The biodegradable polyester resin composition according to the embodiment may contain the biodegradable resin in a content of about 99 wt% or more based on the weight of the entire composition. The maximum content of the biodegradable resin in the biodegradable polyester resin composition according to the embodiment may be about 100 wt% based on the weight of the entire composition.

[0203] 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. Also, the reinforcing material can adjust the deformation characteristics of the biodegradable polyester resin composition according to the embodiment due to ultraviolet rays. Also, the reinforcing material can adjust the hydrolysis characteristics of the biodegradable polyester resin composition according to the embodiment. Also, the reinforcing material can adjust the biodegradability of the biodegradable polyester resin according to the embodiment.

[0204] The reinforcing material may be derived from biomass. The reinforcing material may be a fiber made of an organic substance. The reinforcing material may be nanocellulose.

[0205] The nano-cellulose 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.

[0206] The nano-cellulose may contain a metal bonded by an ionic bond. 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.

[0207] The nano-cellulose may be represented by Chemical Formula 13 below.

[0208] [Chemical Formula]

[0209] Here, x is 1 to 35, and y may be 1 to 10. x is 15 to 35, and y may be 1 to 10.

[0210] The nano-cellulose may have a specific surface area of about 200 m 2 / g to about 600 m 2 / g. The nano-cellulose may have a specific surface area of about 250 m 2 / g to about 500 m 2 / g.

[0211] The weight average molecular weight of the nanocellulose may be about 10,000 g / mol to about 40,000 g / mol. The weight average molecular weight of the nanocrystalline cellulose may be about 11,000 g / mol to about 35,000 g / mol.

[0212] The moisture content of the nanocrystalline cellulose may be about 2 wt% to about 8 wt%. The moisture content of the nanocrystalline cellulose may be about 4 wt% to about 6 wt%.

[0213] The average diameter of the nanocellulose may be about 0.5 nm to about 10 nm. The average diameter of the nanocellulose may be about 1 nm to about 8 nm. The average diameter of the nanocellulose may be about 1.5 nm to about 7 nm.

[0214] The average length of the nanocellulose may be about 20 nm to about 300 nm. The average length of the nanocellulose may be about 30 nm to about 180 nm. The average length of the nanocellulose may be about 35 nm to about 150 nm.

[0215] By the diameter and length of the nanocellulose satisfying 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.

[0216] The diameter and length of the nanocellulose can be measured by atomic force microscopy in a state of being dispersed in water.

[0217] The sulfur content of the nanocellulose may be about 0.1 wt% to about 1.2 wt% based on the whole of the nanocrystalline cellulose. The sulfur content of the nanocrystalline cellulose may be about 0.2 wt% to about 1.1 wt% based on the whole of the nanocellulose.

[0218] The pH of the nanocellulose may be 5 to 8. The pH of the nanocellulose may be 6 to 8.

[0219] The zeta potential of the nanocellulose may be from about -25 mV to about -50 mV. The zeta potential of the nanocellulose may be from about -30 mV to about -45 mV.

[0220] The nanocellulose may be included in the biodegradable polyester resin composition according to the examples in 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 in 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 in 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 in 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.

[0221] Since the nanocellulose has the above characteristics, it can be uniformly dispersed in the biodegradable polyester resin composition according to the examples.

[0222] Since the nanocellulose has the above characteristics, the mechanical properties of the biodegradable polyester resin composition according to the examples can be improved.

[0223] In addition, the nanocellulose functions as a nucleating agent and can improve the crystallization rate of the biodegradable polyester resin composition according to the examples. Thereby, the nanocellulose can increase the crystallization temperature of the biodegradable polyester resin composition according to the examples.

[0224] Since the nanocellulose has the above characteristics, the biodegradable polyester resin composition according to the examples may have appropriate UV resistance characteristics.

[0225] Since the nanocellulose has the above characteristics, the biodegradable polyester resin composition according to the examples may have an appropriate biodegradation rate.

[0226] Since the nanocellulose has the above characteristics, the biodegradable polyester resin composition according to the examples may have an appropriate hydrolysis rate.

[0227] The biodegradable polyester resin composition according to the examples may contain a metal salt.

[0228] 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.

[0229] At least one or more of the metal salts may be selected from the group consisting of nitrates, sulfates, hydrochlorides, or carboxylates. 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, or silver salts. 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, or sodium nitrate.

[0230] 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).

[0231] Also, the metal salt may be selected from the group consisting of acetate, nitrate, nitride, sulfide, sulfate, sulfoxide, hydroxide, hydrate, chloride, chlorinate, and bromide.

[0232] The biodegradable polyester resin composition according to the examples contains the metal salt in the above content, so the hydrolysis rate and biodegradation rate can be appropriately adjusted.

[0233] The biodegradable polyester resin composition according to the examples may further contain a hydrolysis-resistant agent.

[0234] The hydrolysis-resistant agent may be selected from at least one or more silicon-based compounds such as silane, silazane, or siloxane.

[0235] The hydrolysis-resistant agent may contain an alkoxysilane. The hydrolysis-resistant agent may contain trimethoxysilane and / or triethoxysilane. The hydrolysis-resistant agent may contain an alkoxysilane containing an epoxy group. The hydrolysis-resistant agent may contain at least one or more selected from the group consisting of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-Glycidoxypropyl methyldimethoxysilane, 3-Glycidoxypropyl trimethoxysilane, 3-Glycidoxypropyl methyldiethoxysilane, or 3-Glycidoxypropyl triethoxysilane.

[0236] The hydrolysis-resistant agent may be contained in the biodegradable polyester resin composition according to the examples in an amount of about 1 ppm to about 10,000 ppm. The hydrolysis-resistant agent may be contained in the biodegradable polyester resin composition according to the examples in an amount of about 1 ppm to about 1,000 ppm. The hydrolysis-resistant agent may be contained in the biodegradable polyester resin composition according to the examples in an amount of about 5 ppm to 500 ppm. The hydrolysis-resistant agent may be contained in the biodegradable polyester resin composition according to the examples in an amount of about 10 ppm to 300 ppm.

[0237] The hydrolysis-resistant agent may be bonded to the biodegradable polyester resin. The hydrolysis-resistant agent may be chemically bonded to the biodegradable polyester resin. The hydrolysis-resistant agent may be chemically bonded to the polymer contained in the biodegradable polyester resin. The hydrolysis-resistant agent can couple the polymers contained in the biodegradable polyester resin to each other.

[0238] The biodegradable polyester resin composition according to the examples may have appropriate hydrolysis resistance characteristics because it contains the hydrolysis-resistant agent within the above range. In particular, the biodegradable polyester resin according to the examples may have appropriate initial hydrolysis characteristics and improved biodegradability because it contains the hydrolysis-resistant agent within the above range.

[0239] As a result, the biodegradable polyester resin composition according to the examples may contain a silicon element. The biodegradable polyester resin composition according to the examples may contain a silicon element at a content of about 0.1 ppm to about 100 ppm. The biodegradable polyester resin composition according to the examples may contain a silicon element at a content of about 0.1 ppm to about 50 ppm. The biodegradable polyester resin composition according to the examples may contain a silicon element at a content of about 0.1 ppm to about 20 ppm.

[0240] Also, the hydrolysis-resistant agent can also react with terminal carboxyl groups or unreacted carboxyl groups. As a result, the biodegradable polyester resin composition according to the examples may have a low acid value.

[0241] Also, the hydrolysis-resistant agent can couple the polymers contained in the biodegradable polyester resin, so that the proportion of high-molecular-weight polymers in the biodegradable polyester resin composition according to the examples can be increased. As a result, the mechanical properties of the biodegradable polyester resin composition according to the examples can be improved.

[0242] The biodegradable polyester resin composition according to the examples may further contain a chain extender.

[0243] The chain extender may contain isocyanate.

[0244] The chain extender may be at least one selected from the group consisting of monofunctional isocyanates or polyfunctional isocyanates.

[0245] The chain extender may be at least one selected from the group consisting of tolylene 2,4-diisocyanate, tolylene 2,6-diisocyanate, diphenylmethane 4,4'-diisocyanate, 2,4'-diisocyanate, naphthalene 1,5-diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, isophorone diisocyanate, and methylene bis(4-isocyanatocyclohexane).

[0246] The chain extender may contain a triisocyanate. The chain extender may contain tris(4-isocyanatophenyl)methane.

[0247] 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.

[0248] The chain extender may contain a styrene copolymer. The chain extender may contain styrene glycidyl acrylate.

[0249] The chain extender may be chemically bonded to the biodegradable polyester resin. The chain extender may be chemically bonded to a polymer contained in the biodegradable polyester resin. The chain extender may be bonded to the end of a polymer contained in the biodegradable polyester resin. Further, the chain extender may be bonded to the ends of three polymers contained in the biodegradable polyester resin.

[0250] The chain extender may be included in the biodegradable polyester resin composition according to the examples at a content of about 0.1 wt% to about 10 wt%. The chain extender may be included in the biodegradable polyester resin composition according to the examples at a content of about 0.2 wt% to about 8 wt%. The chain extender may be included in the biodegradable polyester resin composition according to the examples at a content of about 0.3 wt% to about 7 wt%.

[0251] 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.

[0252] Also, the chain extender can react with both terminal carboxyl groups and unreacted carboxyl groups. As a result, the biodegradable polyester resin composition according to the examples may have a low acid value.

[0253] Also, the chain extender can couple the polymers contained in the biodegradable polyester resin, and the biodegradable polyester resin composition according to the examples can increase the proportion of high-molecular-weight polymers. As a result, the mechanical properties of the biodegradable polyester resin composition according to the examples can be improved.

[0254] The biodegradable polyester resin composition according to the examples may contain oligomers. The molecular weight of the oligomers may be about 400 to about 1300.

[0255] The oligomer may be included in the biodegradable polyester resin composition according to the examples at about 3000 ppm to about 30000 ppm, based on the total resin composition. The oligomer may be included in the biodegradable polyester resin composition according to the examples at about 5000 ppm to about 20000 ppm, based on the total resin composition. The oligomer may be included in the biodegradable polyester resin composition according to the examples at about 5000 ppm to about 15000 ppm, based on the total resin composition. The oligomer may be included in the biodegradable polyester resin composition according to the examples at about 7000 ppm to about 15000 ppm, based on the total resin composition.

[0256] 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.

[0257] The oligomer may include an oligomer in which the molar ratio of the aliphatic dicarboxylic acid is higher than the molar ratio of the aromatic dicarboxylic acid. Among the oligomers, the ratio of the oligomer containing relatively more of the aliphatic dicarboxylic acid may be even higher than the ratio of the oligomer containing relatively more of the aromatic dicarboxylic acid.

[0258] 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.

[0259] 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.

[0260] The biodegradable polyester resin composition according to the embodiment may contain a heat stabilizer. The heat stabilizer may be a phosphorus-based heat stabilizer.

[0261] The heat stabilizer may be at least one selected from the group consisting of amine-based high-temperature heat stabilizers such as tetraethylenepentamine, triethyl phosphonoacetate, phosphoric acid, phosphorous acid, polyphosphric acid, trimethyl phosphate (TMP), triethyl phosphate, trimethyl phosphine, or triphenyl phosphine.

[0262] Also, the heat stabilizer may be an antioxidant having an antioxidant function.

[0263] The content of the heat stabilizer may be about 3000 ppm or less based on the total weight of the biodegradable polyester resin. The content of the heat stabilizer may be, for example, 10 ppm to 3,000 ppm, 20 ppm to 2,000 ppm, 20 ppm to 1,500 ppm, or 20 ppm to 1,000 ppm based on the total weight of the biodegradable polyester resin. By the content of the heat stabilizer satisfying the above range, the deterioration of the polymer due to high temperature during the reaction process can be controlled, the end groups of the polymer can be reduced, and the color can be improved. Also, the heat stabilizer can suppress the activation of a titanium-based catalyst or the like and adjust the reaction rate.

[0264] The biodegradable polyester resin composition according to the embodiment may contain an elongation improver. Examples of the elongation improver may 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.

[0265] The elongation improver may be contained in the biodegradable polyester resin composition according to the embodiment in an amount of about 0.001 parts 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 embodiment in an amount of about 0.01 parts by weight to about 1 part by weight based on 100 parts by weight of the biodegradable polyester resin.

[0266] The biodegradable polyester resin composition according to the embodiment may contain an inorganic filler. The inorganic filler may be at least one selected from the group consisting of calcium sulfate, barium sulfate, talc, talcum powder, bentonite, kaolin, chalk powder, calcium carbonate, graphite, gypsum, electrically conductive carbon black, calcium chloride, iron oxide, aluminum oxide, potassium oxide, dolomite, silicon dioxide, wollastonite, titanium dioxide, silicate, mica, glass fiber, or mineral fiber.

[0267] Regarding the inorganic filler, based on the volume in the particle size distribution obtained by the laser diffraction method, the particle size (D 50 ) at cumulative 50% 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.

[0268] Also, the specific surface area of the inorganic filler may be about 100 m 2 / g or more. For example, the specific surface area of the inorganic filler may be about 100 m 2 / g or more, about 105 m 2110 m or more 2 It may be 110 m or more.

[0269] The inorganic filler may be included in the biodegradable polyester resin composition according to the examples in an amount of about 3 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 to about 30 parts by weight based on 100 parts by weight of the biodegradable polyester resin.

[0270] 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 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.

[0271] 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, appropriate biodegradation rate, and appropriate hydrolysis rate of the biodegradable polyester resin composition according to the examples.

[0272] The biodegradable polyester resin composition according to the examples may further contain two types of biodegradable polyester resins. The biodegradable polyester resin composition according to the examples may be a composite resin composition containing two or more types of resins, fillers, and additives.

[0273] The two biodegradable polyester resins may be selected from at least one or more of the group consisting of polybutylene azelate terephthalate (PBAzT), polybutylene sebacate terephthalate (PBSeT), polybutylene succinate terephthalate (PBST), polyhydroxyalkanoate (PHA), or polylactic acid (PLA).

[0274] The two biodegradable polyester resins may be included in the biodegradable polyester resin composition according to the examples at a content of about 10 parts by weight to about 100 parts by weight based on 100 parts by weight of the biodegradable polyester resin. The two biodegradable polyester resins may be included in the biodegradable polyester resin composition according to the examples at a content of about 10 parts by weight to about 60 parts by weight based on 100 parts by weight of the biodegradable polyester resin. The two biodegradable polyester resins may be included in the biodegradable polyester resin composition according to the examples at a content of about 20 parts by weight to about 50 parts by weight based on 100 parts by weight of the biodegradable polyester resin.

[0275] The two biodegradable polyester resins can complement the physical properties, mechanical, optical and chemical properties of the biodegradable polyester resin. Since the biodegradable polyester resin composition according to the examples contains the two biodegradable polyester resins at the above content, it may have mechanical properties, appropriate UV resistance, appropriate biodegradation rate, and appropriate hydrolysis rate of the biodegradable polyester resin composition according to the examples.

[0276] In addition, the number of terminal carboxyl groups in the biodegradable polyester resin composition according to the examples may be about 50 eq / ton or less. For example, the number of terminal carboxyl groups in the biodegradable polyester resin according to the examples may be about 50 eq / ton or less, about 48 eq / ton or less, about 45 eq / ton or less, or about 42 eq / ton or less. When the number of terminal carboxyl groups is adjusted within the above range and the biodegradable polyester resin composition according to the examples is extruded to form a molded product, deterioration can be prevented and improved mechanical properties can be realized.

[0277] In addition, 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 of other examples may be about 1.4 dl / g to about 1.7 dl / g.

[0278] The process of manufacturing the biodegradable polyester resin composition according to the examples is as follows.

[0279] 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.

[0280] The method for manufacturing the biodegradable polyester resin includes a step of manufacturing a slurry containing the diol and the aromatic dicarboxylic acid.

[0281] The step of manufacturing the slurry includes a step of mixing and processing the diol and the aromatic dicarboxylic acid. That is, the step of manufacturing the slurry is a pretreatment step before the esterification reaction, and may be a step of mixing the diol and the aromatic dicarboxylic acid to form a slurry. At this time, the diol may contain a biomass-based diol component.

[0282] 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.

[0283] The diol and the aromatic dicarboxylic acid can be put into the slurry stirrer 100 and stirred to produce the slurry.

[0284] By mixing and pretreating the diol and the aromatic dicarboxylic acid to form a slurry, not only can the diol and the aromatic dicarboxylic acid react uniformly, but it is also effective in promptly carrying out the esterification reaction, so the reaction efficiency can be increased.

[0285] In particular, when the aromatic dicarboxylic acid has complete crystallinity and is in powder form, such as terephthalic acid, its solubility in the diol is very low, and a homogeneous reaction may not easily occur. Therefore, the pretreatment process of forming a slurry plays a very important role in providing a biodegradable polyester resin, sheet, film, and molded product having excellent physical properties according to embodiments of the present invention and enhancing the reaction efficiency.

[0286] When the aromatic dicarboxylic acid is terephthalic acid, the terephthalic acid has complete crystallinity, is a white crystal that sublimates near 300 °C under normal pressure without a melting point, has a very low solubility in the diol, and it is difficult for a homogeneous reaction to occur. Therefore, when a pretreatment process is performed before the esterification reaction, since it reacts with the diol within the solid matrix of terephthalic acid, the surface area can be increased to induce a uniform reaction.

[0287] Also, when the aromatic dicarboxylic acid is dimethyl terephthalate, since the pretreatment process can make the dimethyl terephthalate in a molten state at about 142 °C to 170 °C and react it with the diol, the esterification reaction rate can be made even faster and more efficient.

[0288] On the other hand, in the pretreatment stage of manufacturing the slurry, the structure and physical properties of the biodegradable polyester resin may vary depending on the particle size, particle size distribution, pretreatment reaction conditions, etc. of the aromatic dicarboxylic acid.

[0289] For example, the aromatic dicarboxylic acid contains terephthalic acid, and the average particle size (D50) of the terephthalic acid measured by a particle size analyzer Microtrac S3500 in the particle size distribution (PSD) may be 10 μm to 400 μm, and the standard deviation with respect to the average particle size (D50) may be 100 or less. The standard deviation means the square root of the dispersion. The average particle size (D50) of the terephthalic acid may be 20 μm to 200 μm, for example, 30 μm to 180 μm, or for example, 100 μm to 160 μm. When the average particle size (D50) of the terephthalic acid satisfies the above range, it may be more advantageous in terms of improving the solubility in the diol and the reaction rate.

[0290] In the pretreatment process, the diol and the aromatic dicarboxylic acid can be mixed and put into a slurry stirrer 100 (tank).

[0291] The slurry stirrer 100 may, for example, have an anchor type at the bottom, a height to the agitator of 20 mm or more, and be equipped with three or more rotating blades, which may be more advantageous for achieving an efficient stirring effect.

[0292] For example, in the slurry stirrer 100, the height to the agitator may be 20 mm or more, that is, there may be almost contact between the reactor and the bottom of the agitator. In this case, a slurry can be obtained without precipitation. If the pattern, form, and rotating blades of the agitator do not meet the above conditions, when the diol and the aromatic dicarboxylic acid are initially mixed, the aromatic dicarboxylic acid may settle to the bottom, and in this case, phase separation may occur.

[0293] The pretreatment step for manufacturing the slurry may include a step of mixing the diol and the aromatic dicarboxylic acid and stirring at about 30°C to about 100°C, at about 50 rpm to about 200 rpm, for 10 minutes or more, for example, for 10 minutes to 200 minutes.

[0294] The diol may have the characteristics as described above.

[0295] The diol can be charged all at once or dividedly. For example, the diol can be divided and charged when mixing with the aromatic dicarboxylic acid and when mixing with the aliphatic dicarboxylic acid.

[0296] The aromatic dicarboxylic acid may have the same characteristics as described above.

[0297] In the pretreatment stage for manufacturing the slurry, the molar ratio of the diol to the aromatic dicarboxylic acid may be about 0.8:1 to about 2:1. In the pretreatment stage for manufacturing the slurry, the molar ratio of the diol to the aromatic dicarboxylic acid may be about 1.1:1 to about 1.5:1. In the pretreatment stage for 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.

[0298] When the diol is charged in an amount even larger than that of the aromatic dicarboxylic acid, the aromatic dicarboxylic acid can be easily dispersed.

[0299] In addition, an additive can be charged into the slurry. The nanocellulose and / or the metal salt may be added to the slurry in the form of a dispersion or a solution.

[0300] The method for producing the biodegradable polyester resin includes mixing a diol and an aromatic dicarboxylic acid, subjecting the obtained slurry after pretreatment to an esterification reaction to obtain a prepolymer, and subjecting the prepolymer to a polycondensation reaction, whereby the structure and physical properties of the target biodegradable polyester resin according to the embodiments of the present invention can be efficiently achieved.

[0301] The method for producing the biodegradable polyester resin includes a step of subjecting the slurry and the aliphatic dicarboxylic acid to an esterification reaction to produce a prepolymer. The slurry and the aliphatic dicarboxylic acid can react in the ester reaction section.

[0302] In the esterification reaction, by using the slurry, the reaction time can be shortened. For example, the slurry obtained in the pretreatment step can shorten the reaction time of the ester reaction by 1.5 times or more.

[0303] The esterification reaction can be carried out at least twice or more. A prepolymer to be introduced into the polycondensation step can be formed by the esterification reaction.

[0304] 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 charged into the esterification reactor, and the aliphatic dicarboxylic acid alone, or the aliphatic dicarboxylic acid and the diol can be charged into the esterification reactor to carry out the esterification reaction.

[0305] The diol and the aliphatic dicarboxylic acid may be added to the slurry containing the aromatic dicarboxylic acid in a slurry state.

[0306] 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.

[0307] In the esterification reaction, the total number of moles of the diol charged may be about 1.0 to about 1.8 with respect to the total number of moles of the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid. In the esterification reaction, the total number of moles of the diol charged may be about 1.1 to about 1.6 with respect to the total number of moles of the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid.

[0308] 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.

[0309] Also, various additives such as the nanocellulose may be added to the slurry of the diol and the aliphatic dicarboxylic acid.

[0310] 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.

[0311] 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.

[0312] Further, after the first ester reaction, a mixture of the slurry, the aliphatic dicarboxylic acid and the diol is 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.

[0313] 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 1.5 hours to 3 hours, but is not limited thereto.

[0314] 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.

[0315] In the first ester reaction and the second ester reaction, the reaction temperature, reaction time, and the contents of the diol, aromatic dicarboxylic acid, and aliphatic dicarboxylic acid introduced are respectively adjusted to adjust the number ratio of the first block and the second block, the ratio of the alternation, the ratio of the hard segment, and the ratio of the soft segment, etc. Further, when the ester reaction is carried out separately as the first ester reaction and the second ester reaction, the overall ester reaction can be precisely controlled. Thereby, when the ester reaction is carried out separately, the reaction stability and reaction uniformity of the ester reaction can be improved.

[0316] Further, in the second ester reaction, the branching agent can be further added. That is, the slurry, the aliphatic dicarboxylic acid, the mixture of the diol, the branching agent, and the first ester reaction product can react to form the prepolymer. The characteristics and content of the branching agent may be the same as those described above.

[0317] After the second ester reaction is completed, a third ester 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 second ester reaction product to carry out the third ester reaction.

[0318] The monomer composition may be added to the second ester reaction product in an amount of about 0.5 parts by weight to about 10 parts by weight based on 100 parts by weight of the second ester reaction product.

[0319] 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.

[0320] 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.

[0321] The third ester 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.

[0322] A prepolymer can be formed by the third esterification reaction.

[0323] When the third ester 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.

[0324] In the third esterification reaction, the second esterification reaction product 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 second esterification reaction product and the third esterification reaction product can be mixed with each other to produce the prepolymer. At this time, the third esterification reaction product can be mixed with the second esterification reaction product in a content of about 0.1 part by weight to about 5 parts by weight based on 100 parts by weight of the second esterification reaction product to produce the prepolymer.

[0325] The number-average molecular weight of the prepolymer may be about 500 to about 10,000 g / mol. For example, the number-average molecular weight of the prepolymer may be about 500 to about 8,500 g / mol, about 500 to about 8,000 g / mol, about 500 to about 7,000 g / mol, about 500 g / mol to about 5,000 g / mol, or 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.

[0326] 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 them, the molecular weight can be measured based on the number-average molecular weight (Mn).

[0327] The reinforcing material and / or the metal salt may be introduced together with the slurry before the esterification reaction. The reinforcing material and / or the metal salt may be introduced into the esterification reaction section 200 during the esterification reaction. The reinforcing material and / or the metal salt may be introduced into the ester reaction product after the esterification reaction. Further, the reinforcing material and / or the metal salt may be introduced together with the aliphatic dicarboxylic acid. Further, the reinforcing material and / or the metal salt may be introduced into the esterification reaction section 200 after the first ester reaction and before the second ester reaction.

[0328] Since the reinforcing material and / or the metal salt are introduced into the esterification reaction, the reinforcing material and / or the metal salt may be uniformly dispersed in the biodegradable polyester resin.

[0329] The reinforcing material may have the characteristics described above. In particular, the nanocellulose can be used as the reinforcing material.

[0330] 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 bead mill pretreated or ultrasonically pretreated with water-dispersed nanocellulose.

[0331] First, the bead mill pretreatment can be performed with a vertical mill or a horizontal mill as a wet milling device. Although the horizontal mill is preferable in that it can hold a larger amount of beads inside the chamber, reduces mechanical uneven wear, reduces bead wear, and is easy to maintain, it is not limited thereto.

[0332] 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.

[0333] 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.

[0334] By satisfying the above range of the bead diameter, the dispersibility of nanocellulose can be further improved. When the bead diameter exceeds the above range, the average particle size and particle size deviation of nanocellulose may increase, resulting in low dispersibility.

[0335] Also, it is preferable to use beads having a higher specific gravity 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 having a higher specific gravity than that of water-dispersed nanocellulose, and zirconium beads having a specific gravity 4 times or more higher than that of the water-dispersed nanocellulose are preferable, but not limited thereto.

[0336] Also, the ultrasonic pretreatment is a method of discharging ultrasonic waves of 20 kHz into a solution and physically closing or pulverizing nanoparticles by the generated waves.

[0337] The ultrasonic pretreatment can be carried out at an output of 30000 J / s or less for a time of less than 30 minutes. For example, the ultrasonic pretreatment can be carried out 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 become low.

[0338] The nanocellulose according to the embodiment may be one that has been subjected to bead mill pretreatment or ultrasonic pretreatment. Alternatively, the nanocellulose according to the embodiment may be one that has been subjected to both bead mill pretreatment and ultrasonic pretreatment. At this time, it is preferable to perform ultrasonic pretreatment after the bead mill pretreatment in terms of preventing re-aggregation and improving dispersibility.

[0339] The nanocellulose according to the embodiment may be one that has been subjected to bead mill pretreatment or ultrasonic pretreatment. Alternatively, the nanocellulose according to the embodiment may be one that has been subjected to both bead mill pretreatment and ultrasonic pretreatment. At this time, it is preferable to perform ultrasonic pretreatment after the bead mill pretreatment in terms of preventing re-aggregation and improving dispersibility.

[0340] Since the nanocellulose contains ionically bonded metal, its dispersibility in water is very high. Further, a very 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 nanocellulose aqueous dispersion may be about 1 wt% to about 50 wt%.

[0341] A titanium-based catalyst and / or a germanium-based catalyst can be used for the esterification reaction. Specifically, the titanium-based catalyst and / or the germanium-based catalyst can be added to the slurry to carry out the esterification reaction.

[0342] Also, 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.

[0343] 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.

[0344] Also, 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 950 ppm. By satisfying the above range of the catalyst content, the physical properties can be further improved.

[0345] Also, the heat stabilizer may be introduced together with the slurry before the esterification reaction. The heat stabilizer may be introduced into the esterification reaction unit 200 during the esterification reaction. The heat stabilizer may be introduced into the ester reaction product after the esterification reaction. Also, the heat stabilizer may be introduced together with the aliphatic dicarboxylic acid. Also, the heat stabilizer may be introduced into the esterification reaction unit 200 after the first ester reaction and before the second ester reaction.

[0346] The characteristics of the heat stabilizer may be the same as those described above.

[0347] The content of the heat stabilizer may be 3,000 ppm or less based on the total weight of the diol, aromatic dicarboxylic acid, and aliphatic dicarboxylic acid. Specifically, the content of the heat stabilizer may be, for example, 10 ppm to 3,000 ppm, 20 ppm to 2,000 ppm, 20 ppm to 1,500 ppm, or 20 ppm to 1,000 ppm based on the total weight of the diol, aromatic dicarboxylic acid, and aliphatic dicarboxylic acid. By the 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.

[0348] After the esterification reaction is completed, one or more selected from the group consisting of additives such as silica, potassium, or magnesium, and color correctors such as cobalt acetate may be further added to the esterification reaction product. That is, after the esterification reaction is completed, the additive and / or color corrector can be added and stabilized, and then the polycondensation reaction can be carried out. The additive and / or the color corrector may be added after the esterification reaction is completed and then introduced into the polycondensation reaction section 300 together with the prepolymer. Thereby, the additive and / or the color corrector may be uniformly dispersed in the biodegradable polyester resin.

[0349] Also, after the esterification reaction is completed, the inorganic filler may be added to the esterification reaction product. That is, after the esterification reaction is completed, the inorganic filler can be introduced and stabilized, and then the polycondensation reaction can be carried out. The characteristics of the inorganic filler are as described above. The inorganic filler can be introduced into the polycondensation reaction section 300 together with the prepolymer to carry out the polycondensation step. Thereby, the inorganic filler can be uniformly dispersed in the biodegradable polyester resin.

[0350] In addition, 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.

[0351] 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.

[0352] The prepolymer is introduced into the polycondensation reaction unit 300. Further, at least one of the reinforcing material, the heat stabilizer, the color corrector, the inorganic filler, the metal salt, or other additives may be introduced into the polycondensation reaction unit 300 together with the prepolymer.

[0353] 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.

[0354] In addition, the polycondensation reaction may include a primary polycondensation and a secondary polycondensation.

[0355] 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 hour to about 3.5 hours, about 0.5 hour to about 3.0 hours, or about 0.5 hour to about 2.8 hours.

[0356] Further, the second 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, 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.

[0357] 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 stabilizers such as trimethyl phosphate, triphenyl phosphate, trimethylphosphine, 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.

[0358] The number average molecular weight of the polymer may be about 30,000 g / mol or more. For example, the number average molecular weight of the polymer may be about 33,000 g / mol or more, about 35,000 g / mol or more, or about 40,000 g / mol to about 90,000 g / mol. By the number average molecular weight of the polymer satisfying the above range, physical properties, impact resistance, durability, and moldability can be further improved.

[0359] 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 recover the by-products generated in the polycondensation reaction by applying a vacuum pressure to the polycondensation reaction unit 300.

[0360] 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.

[0361] 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.

[0362] Alternatively, the hydrolysis-resistant agent and / or the chain extender may be added to the polycondensation reaction unit 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 unit 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 unit 300 may be about 1 minute to about 15 minutes.

[0363] The hydrolysis-resistant agent may have the same characteristics as described above.

[0364] The chain extender may have the same characteristics as described above.

[0365] As a result, the biodegradable polyester resin composition according to the example may have an appropriate degree of hydrolysis and a high degree of biodegradability.

[0366] Thereafter, pellets can be produced from the polymer.

[0367] 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.

[0368] The cutting step can be carried out without limitation using a 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.

[0369] The pellets can undergo further post-treatment steps. The pellets can be introduced into the post-treatment unit 400 to perform the post-treatment steps.

[0370] The post-treatment steps can be carried out within the post-treatment unit 400. The pellets are introduced into the post-treatment unit 400. Thereafter, the post-treatment unit 400 can melt the introduced pellets by frictional heat and re-extrude them. That is, the post-treatment unit 400 may include a pressing machine such as a twin-screw extruder.

[0371] The post-treatment step temperature may be about 230 °C to about 270 °C. The post-treatment step temperature may be about 230 °C to about 260 °C. The post-treatment step temperature may be about 240 °C to about 265 °C. The post-treatment step temperature may be about 240 °C to about 260 °C.

[0372] The post-treatment step time may be about 30 seconds to about 3 minutes. The post-treatment step time may be about 50 seconds to about 2 minutes. The post-treatment step time may be about 1 minute to about 2 minutes.

[0373] 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.

[0374] The crystallinity of the pellets can be improved in the post-treatment step. Also, the content of the residues contained in the pellets can be adjusted in the post-treatment step. In particular, the content of the oligomers contained in the pellets can be adjusted by the post-treatment step. The content of the residual solvent contained in the pellets can be adjusted by the post-treatment step.

[0375] Thereby, the post-treatment step can appropriately adjust the mechanical properties, biodegradability, UV resistance, optical properties, or hydrolysis resistance of the biodegradable polyester resin.

[0376] After the pellets are manufactured, the biodegradable polyester resin can be compounded with the two types of biodegradable polyester resins. Also, at least one 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 types of biodegradable polyester resins.

[0377] The compounding step is as follows.

[0378] The biodegradable polyester resin and the two types of biodegradable polyester resins are mixed with at least one of the inorganic filler, the heat stabilizer, the color corrector, the metal salt, or the other additives and fed into an extruder. The mixed biodegradable polyester resin composition melts at a temperature of about 120°C to about 260°C in the extruder and mixes with each other. Thereafter, the melt-mixed biodegradable polyester resin composition is extruded, cooled, cut, and re-pelletized. By such a process, the two types of biodegradable polyester resins can be compounded to produce a biodegradable polyester resin composition according to an example.

[0379] In contrast, the inorganic filler, the heat stabilizer, the color corrector, the metal salt, and the other additives may be added during the process of polymerizing the biodegradable polyester resin.

[0380] The biodegradable polyester resin composition according to the examples can be used to produce a biodegradable polyester film.

[0381] 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.

[0382] The biodegradable polyester film according to the examples may have substantially the same degree of hydrolysis and biodegradability as the biodegradable polyester resin composition described above.

[0383] On the other hand, the biodegradable polyester film can be produced using the biodegradable polyester resin or biodegradable polyester resin pellets.

[0384] Specifically, the method for producing the biodegradable polyester film may include the step of producing the biodegradable polyester resin composition according to the examples and the step of drying and melt-extruding the biodegradable polyester resin composition.

[0385] In the step of drying and melt-extruding the biodegradable polyester resin composition, the drying can be carried out at about 60°C to about 100°C for about 2 hours to about 12 hours. Specifically, the drying can be carried out 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 article 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.

[0386] In the step of drying and melt-extruding, the melt-extrusion can be carried out at a temperature of about 250°C or lower. For example, the melt-extrusion can be carried out 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 carried out in a blown film process. The melt-extrusion can be carried out with a T-die.

[0387] Also, the film manufacturing process may be a calendaring process.

[0388] A biodegradable polyester molded article can be manufactured using the biodegradable polyester resin.

[0389] 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 an injection molded article, an extrusion molded article, a thin film molded article, blow molding, or a blow molded article, a 3D filament, an interior building material, etc., but is not limited thereto.

[0390] 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, perishable garbage bags, etc., or may be in the form of fibers used for textiles, knitted fabrics, non-woven fabrics, ropes, etc. Further, as shown in FIG. 2, the molded article may be in the form of a disposable container used for food packaging containers such as lunch boxes. Further, the molded article may be molded articles in various forms such as disposable straws, spoons and chopsticks, food plates, forks, etc.

[0391] In particular, since the molded article can be formed of the biodegradable polyester resin which can improve not only physical properties such as impact absorption energy and hardness but also particularly impact resistance and durability, it can be used for packaging materials of products stored and transported at low temperatures, interior materials for automobiles that require durability, garbage bags, mulching films, and disposable products, and can exhibit excellent characteristics.

[0392] The physical properties of the biodegradable film and the biodegradable molded article can be measured in a manner similar to the biodegradable polyester resin composition according to the examples.

[0393] The biodegradable polyester resin composition according to the examples can measure the biodegradability by the following method.

[0394] In order to measure the biodegradability, the biodegradable polyester resin composition according to the examples was mixed with compost and a biodegradation acceleration test was carried out at a temperature of 60° C. and a humidity of 90%. After a certain period of time, the number average molecular weight of the biodegradable polyester resin composition according to the examples was measured using gel permeation chromatography (GPC). The biodegradability was derived from the value obtained by dividing the difference between the initial number average molecular weight and the number average molecular weight after biodegradation for a certain period by the initial number average molecular weight.

[0395] The biodegradability may be represented by the following mathematical formula 10.

[0396] [Formula 10] JPEG2025517983000024.jpg16161

[0397] Here, the biodegradable polyester resin composition according to the example is mixed with compost and subjected to an accelerated biodegradation test at a temperature of 60°C and a humidity of 90% for a certain period. Before the accelerated biodegradation test is carried out, the initial number average molecular weight of the biodegradable polyester resin composition and the number average molecular weight after biodegradation of the biodegradable polyester resin composition that has undergone the accelerated biodegradation test for a certain period are measured by gel permeation chromatography (GPC).

[0398] The biodegradability was derived from the value obtained by dividing the difference between the initial number average molecular weight and the number average molecular weight after biodegradation for a certain period by the initial number average molecular weight.

[0399] Also, the compost may contain about 40 wt% pig manure, about 15 wt% chicken manure, about 37 wt% large sawdust, about 5 wt% zeolite, and about 3 wt% microbial preparation.

[0400] Also, the manufacturer of the compost may be Taeheung F&G, and the product name of the compost may be Jisheng soil (by-product fertilizer grade 1 compost).

[0401] Also, when the biodegradability is measured, the biodegradable polyester resin composition according to the example is manufactured into a sheet having a thickness of about 300 μm. Then, the manufactured sheet is cut into a size of about 30 mm × 30 mm to produce flakes. The flakes can be mixed with the compost to perform the accelerated biodegradation test.

[0402] In the biodegradable polyester resin composition according to the example, the biodegradation degree after 1 week may be about 40% to about 70%. In the biodegradable polyester resin composition according to the example, the biodegradation degree after 1 week may be about 45% to about 65%. In the biodegradable polyester resin composition according to the example, the biodegradation degree after 1 week may be about 47% to about 63%. In the biodegradable polyester resin composition according to the example, the biodegradation degree after 1 week may be about 49% to about 62%.

[0403] In the biodegradable polyester resin composition according to the example, the biodegradation degree after 2 weeks may be about 50% to about 70%. In the biodegradable polyester resin composition according to the example, the biodegradation degree after 2 weeks may be about 55% to about 68%.

[0404] In the biodegradable polyester resin composition according to the example, the biodegradation degree after 3 weeks may be about 63% to about 75%. In the biodegradable polyester resin composition according to the example, the biodegradation degree after 3 weeks may be about 63% to about 73%.

[0405] In the biodegradable polyester resin composition according to the example, the biodegradation degree after 4 weeks may be about 73% to about 85%. In the biodegradable polyester resin composition according to the example, the biodegradation degree after 4 weeks may be 75% to 82%.

[0406] In the biodegradable polyester resin composition according to the example, the biodegradation degree after 6 weeks may be about 80% to about 90%. In the biodegradable polyester resin composition according to the example, the biodegradation degree after 6 weeks may be about 82% to about 88%.

[0407] In the biodegradable polyester resin composition according to the example, the biodegradation degree after 9 weeks may be about 85% or more. In the biodegradable polyester resin composition according to the example, the biodegradation degree after 9 weeks may be about 87% or more. In the biodegradable polyester resin composition according to the example, the biodegradation degree after 9 weeks may be about 88% or more. In the biodegradable polyester resin composition according to the example, the biodegradation degree after 9 weeks may be about 89% or more. In the biodegradable polyester resin composition according to the example, the biodegradation degree after 9 weeks may be about 90% or more.

[0408] Since the biodegradable polyester resin composition according to the example has the biodegradation degree and the rate of increase in biodegradation degree as described above, it may have appropriate durability in the actual living area and may have a high biodegradation degree when discarded after use.

[0409] The hydrolysis degree of the biodegradable polyester resin composition according to the example can be measured by the following method.

[0410] In order to measure the hydrolysis degree, the biodegradable polyester resin composition according to the example is immersed in water at 80 °C (100% RH), and then a hydrolysis degree acceleration test is carried out. 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 hydrolysis degree 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.

[0411] The hydrolysis degree may be represented by the following formula 11.

[0412] [Formula 11] JPEG2025517983000025.jpg16165

[0413] 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).

[0414] The degree of hydrolysis was derived from the value obtained by dividing the difference between the initial number average molecular weight and the number average molecular weight after hydrolysis for a certain period by the initial number average molecular weight.

[0415] 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 30 mm × 30 mm to produce flakes. The flakes can be immersed in the warm water to perform the hydrolysis acceleration test.

[0416] 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%.

[0417] 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%.

[0418] In the biodegradable polyester resin composition according to the examples, the degree of hydrolysis after three weeks may be about 90% to about 97%. In the biodegradable polyester resin composition according to the examples, the degree of hydrolysis after three weeks may be about 91% to about 96%.

[0419] 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%.

[0420] 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.

[0421] 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.

[0422] 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.

[0423] In the biodegradable polyester resin composition according to the embodiment, the biodegradability per aliphatic carboxylic acid may be about 1.7 or more. Further, the biodegradability per aliphatic carboxylic acid may be about 1.75 or more. The biodegradability per aliphatic carboxylic acid may be about 1.79 or more. The biodegradability per aliphatic carboxylic acid may be about 1.8 or more. The biodegradability per aliphatic carboxylic acid may be about 1.85 or more. The biodegradability per aliphatic carboxylic acid may be about 1.90 or more. The maximum value of the biodegradability per aliphatic carboxylic acid may be about 4.

[0424] The biodegradability per aliphatic carboxylic acid is a value obtained by dividing the biodegradability after 9 weeks by the ratio of the aliphatic carboxylic acid based on the total dicarboxylic acid. The biodegradability per aliphatic carboxylic acid is a value obtained by dividing the biodegradability after 9 weeks by the ratio of the molar% of the aliphatic carboxylic acid based on the total dicarboxylic acid.

[0425] The biodegradability per aliphatic carboxylic acid may be represented by the following Mathematical formula 12.

[0426] [Mathematical formula 12] JPEG2025517983000026.jpg13157

[0427] The composition of the biodegradable polyester resin such as the number of the first blocks, the number of the second blocks, the ratio of the alternation, the ratio of the hard segment, the ratio of the soft segment, the content of the aliphatic dicarboxylic acid, or the content of the aromatic dicarboxylic acid, the process conditions for producing the biodegradable polyester resin, the reinforcing material, the metal salt, the hydrolysis-resistant agent, the chain extender, the oligomer, or the heat stabilizer, etc. are appropriately adjusted so that the biodegradability per aliphatic carboxylic acid may be within the above range.

[0428] In particular, the biodegradable polyester resin composition according to the examples contains a polyester resin having an appropriate degree of alternation. The content of the diol bonded between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid may be appropriate.

[0429] Thereby, the biodegradable polyester resin may have a structure in which the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid are appropriately arranged alternately. Thereby, the biodegradable polyester resin may have improved crystal properties, and the biodegradable polyester resin composition according to the examples may have improved thermal and mechanical properties.

[0430] Further, since the biodegradable polyester resin has a structure in which the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid are appropriately arranged alternately, the aromatic and aliphatic groups can be appropriately cross-linked within the molecule of the biodegradable polyester resin. Thereby, the biodegradable polyester resin composition according to the examples may simultaneously have an appropriate degree of hydrolysis and an improved degree of biodegradability.

[0431] Further, since the biodegradable polyester resin has the above molecular structure, the biodegradable polyester resin composition according to the examples may have a degree of biodegradability per unit content of the high aliphatic dicarboxylic acid.

[0432] The biodegradable polyester resin composition according to the examples contains a polyester resin having an appropriate proportion of hard segments. The content of the diol bonded between the aromatic dicarboxylic acid and the aromatic dicarboxylic acid may be appropriate.

[0433] As a result, the biodegradable polyester resin may appropriately contain the aromatic dicarboxylic acid and the binding structure in which the aromatic dicarboxylic acid is bound to the diol. As a result, the biodegradable polyester resin may have improved crystal properties, and the biodegradable polyester resin composition according to the examples may have improved thermal and mechanical properties.

[0434] In particular, since the biodegradable polyester resin has the ratio of the hard segment within the above range, the biodegradable polyester resin composition according to the examples may appropriately have a high tensile strength and elongation at break.

[0435] In addition, since the biodegradable polyester resin has the molecular structure as described above, it may have appropriate moisture resistance and solvent resistance. As a result, the biodegradable polyester resin composition according to the examples may have improved printability.

[0436] Therefore, the biodegradable polyester resin composition according to the examples may have improved physical properties during the actual use period and may be easily biodegradable after use.

[0437] Also, the acid value of the biodegradable polyester resin composition according to the examples may be 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 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 about 0.1 mgKOH / g to about 2.5 mgKOH / g.

[0438] Since the biodegradable polyester resin composition according to the examples has an acid value within the above range, it may have the hydrolysis degree characteristics and biodegradation degree characteristics as described above.

[0439] The molded article produced by the biodegradable polyester resin composition according to the example may maintain the required mechanical properties within the actual service life and be efficiently decomposed when discarded.

[0440] The above content will be described in more detail with the following examples. However, the following examples are for illustrative purposes of the present invention, and the scope of the examples is not limited thereto.

[0441] <Production Example> Production of Pretreated Cellulose Nanocrystal Dry powder cellulose nanocrystal (NVC-100, manufacturer: Celluforce) having a particle size of about 1 μm to about 50 μm was dispersed in water at 1% by weight, 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.

[0442] <Example> Example 1 Production of Biodegradable Polyester Resin First stage: The stage of obtaining a slurry by pretreatment As shown in Table 1, the pretreated nanocellulose, 1,4-butanediol (1,4-BDO), and terephthalic acid (TPA) were mixed at a molar ratio (1,4-BDO:TPA) of 1.2:1 and put into a slurry tank (the bottom of the slurry tank is of an anchor type, the height to the agitator is 40 mm, and it is equipped with 3 rotating blades) in a catalyst-free state. At this time, the D50 of the terephthalic acid (TPA) was 130 μm.

[0443] Next, the mixture was stirred at 60 °C and 100 rpm for 1 hour for pretreatment to obtain a slurry without phase separation.

[0444] Second stage: The stage of obtaining a prepolymer Approximately 274 parts by weight of the slurry obtained in the first stage, approximately 18 parts by weight of the 1,4 - butanediol, and approximately 29.2 parts by weight of adipic acid, a mixture (the molar ratio of 1,4 - butanediol, terephthalic acid, and adipic acid is 1.2:1:0.2), were fed into the reactor via a supply line. After introducing 250 ppm of tetrabutyl titanate (manufactured by Dupont, Tyzor TnBT), a titanium - based catalyst, a primary esterification reaction was carried out at 220 °C and atmospheric pressure for about 2 hours until 95% of the by - product water was discharged.

[0445] A mixture of approximately 16.4 parts by weight of slurry, approximately 108 parts by weight of 1,4 - butanediol (1,4 - BDO), and approximately 146 parts by weight of adipic acid (AA) (the molar ratio of 1,4 - butanediol, terephthalic acid, and adipic acid is 1.264:0.064:1) was added to the reaction product. After introducing 200 ppm of tetrabutyl titanate (manufactured by Dupont, Tyzor TnBT), a titanium - based catalyst, based on the total weight of the reaction product and the additional mixture, a secondary esterification reaction was carried out at 210 °C and atmospheric pressure for about 2 hours until 95% of the by - product water was discharged to produce a prepolymer having a number - average molecular weight of 1300 g / mol.

[0446] Step 3: Step of carrying out polycondensation reaction Based on the total weight of the prepolymer, 5 wt% of the produced oligomer, 400 ppm of tetrabutyl titanate (manufactured by Dupont, Tyzor TnBT), a titanium - based catalyst, and 500 ppm of triethylene phosphate stabilizer were added to the prepolymer and stabilized for about 10 minutes. Then, after raising the temperature of the reaction mixture to 250 °C, a polycondensation reaction was carried out at 0.5 torr for 4 hours to produce a polymer having a weight - average molecular weight of 55000 g / mol.

[0447] Thereafter, after cooling the polymer to 5 °C, it was cut with a pellet cutter to obtain biodegradable polyester resin pellets.

[0448] Examples 3 - 7 and Comparative Examples 1 - 2 As shown in Table 1 and Table 2 below, the compositions of the reactants and the process conditions in the primary esterification reaction and the secondary esterification reaction are different. Except for the said content and the said process, other processes were carried out substantially with reference to Example 1.

[0449] Examples 8 to 14 As shown in Table 3 and Table 4 below, the compositions of the reactants and the process conditions in the primary esterification reaction and the secondary esterification reaction are different. Except for the said content and the said process, other processes were carried out substantially with reference to Example 1.

[0450] Manufacture of biodegradable polyester sheet After preparing two Teflon (registered trademark) sheets, a stainless steel (SUS) frame (area 12 cm × 12 cm) was positioned on one Teflon (registered trademark) sheet, and about 7 g of the manufactured polyester resin pellets were put into the stainless steel (SUS) frame (area 12 cm × 12 cm), then covered with the other Teflon (registered trademark) sheet and positioned at the center of a hot press (manufacturer: Withrap, model: WL1600SA) having a surface size of about 25 cm × 25 cm. This was maintained at about 210 °C under a pressure of about 10 Mpa for about 3 minutes, then detached and immediately cooled with water at about 20 °C for about 30 seconds, and a biodegradable polyester sheet with an area of about 10 cm × 10 cm and a thickness of about 300 μm was manufactured.

[0451] 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 (manufacturer: Yujin Engineering) to manufacture a biodegradable polyester film with a thickness of 50 μm.

[0452] [Table 1]

[0453] [Table 2]

[0454]

Table 3

[0455]

Table 4

[0456] <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 Microtrac S3500 (Microtrac Inc) particle size analyzer in the particle size distribution (PSD), the average particle size (D50) and standard deviation (SD, Standard Deviation) of aromatic dicarboxylic acid (TPA or DMT) were determined under the following conditions:

[0457] Use Environment - Temperature: 10~35°C, Humidity: 90%RH, non-condensing maximum - The D50 and SD, which are the average particle size distributions by interval, were measured.

[0458] The standard deviation means the square root of the variance and can be calculated using software.

[0459] <Particle Size of Nanocellulose> Regarding nanocellulose, using a Zetasizer Nano ZS (manufacturer: Marven), the particle size and particle size deviation were measured by the principle of dynamic light scattering (DLS) at a temperature of 25°C and a measurement angle of 175°. At this time, the value of the peak derived from the polydispersity index (PdI) in the 0.5 confidence interval was measured as the particle size.

[0460] Evaluation Example 2: Degree of Hydrolysis The biodegradable polyester resins produced in the examples and comparative examples were immersed in water at 80°C (100% RH), and then a water dispersion degree acceleration test was carried out.

[0461] Specifically, 5 g of the polyester resins of the examples and comparative examples were put into 500 mL of deionized water (DI Water), and then blocked with a stopper so that the water would not evaporate. A hydrolysis acceleration test was carried out in a convection (hot air) oven at 80°C. The humidity environment of the biodegradable polyester sheet is the same as that when immersed in water, which is 100% RH.

[0462] Using gel permeation chromatography (GPC), the number average molecular weight of the polyester resins of the examples and comparative examples after a certain period of time was measured. 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 degree of hydrolysis.

[0463] The GPC equipment and measurement conditions are as follows.

[0464] 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

[0465] Evaluation Example 3: Degree of hydrolysis The biodegradable polyester resins produced in the examples and comparative examples were mixed with the following compost, and a biodegradation acceleration test was carried out at a temperature of 60°C and a humidity of 90%.

[0466] Using the gel permeation chromatography (GPC), the number average molecular weight after a certain period of time was measured in the polyester resins of the examples and comparative examples. The biodegradability was derived as the value obtained by dividing the difference between the initial number average molecular weight and the number average molecular weight after a certain period of time by the initial number average molecular weight.

[0467] Compost Manufacturer: Taeheung G F&G Product name: Native soil (by-product fertilizer grade 1 compost) Compost composition components: 40 wt% pig manure, 15 wt% chicken manure, 37 wt% large sawdust, 5 wt% zeolite, 3 wt% microbial preparation

[0468] Evaluation Example 4: Nuclear magnetic resonance spectroscopy Approximately 5 mg of samples were prepared from the biodegradable polyester resin compositions of the examples and comparative examples, and the samples were 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.

[0469] Apparatus: Manufactured by JEOL, JNM-LA3000 Pulse: Approximately 90° Repetition time: Approximately 4 sec Number of integrations: Measured 8 times Temperature: Approximately 25 °C

[0470] As described in Tables 5 and 6 below, the biodegradabilities in the examples and comparative examples were measured.

[0471]

Table 5

[0472]

Table 6

[0473] As described in Tables 7 and 8 below, the degree of hydrolysis was measured.

[0474]

Table 7

[0475]

Table 8

[0476] As described in Tables 9 and 10 below, 1 The peaks and peak areas by 1H-NMR were measured.

[0477]

Table 9

[0478]

Table 10

[0479] As described in Table 11 below, the degree of crosslinking and the biodegradability after 9 weeks per mole % of adipic acid were derived.

[0480]

Table 11

[0481] As described in Table 12 below, the ratio of crosslinking and the biodegradability after 9 weeks per mole % of adipic acid were derived.

[0482]

Table 12

[0483] As described in Tables 3 to 12 above, the biodegradable polyester resin composition according to the examples may have an appropriate initial degree of hydrolysis and a high late-stage degree of hydrolysis. That is, the biodegradable polyester resin composition according to the examples may have a low initial degree of hydrolysis and a high final degree of hydrolysis.

[0484] In addition, the biodegradable polyester resin composition according to the examples may have an appropriate content of aliphatic carboxylic acid and an appropriate content of aromatic carboxylic acid, and may have a high biodegradability. Thereby, the biodegradable polyester resin composition according to the examples may have a high initial degree of hydrolysis and a high biodegradability.

[0485] In addition, the biodegradable polyester resin composition according to the examples may have a high biodegradability and may have appropriate tensile strength and elongation at break.

Industrial Applicability

[0486] The examples can be used for biodegradable resin compositions, films and molded articles.

Claims

1. A biodegradable polyester resin composition comprising a polyester resin containing a diol, an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid, wherein the crosslinking ratio of the polyester resin is 0.37 to 0.59, and the crosslinking ratio is the ratio of the diol that binds between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid among the diols. A biodegradable polyester resin composition.

2. wherein the crosslinking ratio is 0.4 to 0.56, The biodegradable polyester resin composition according to Claim 1.

3. wherein the crosslinking ratio is 0.45 to 0.53, The biodegradable polyester resin composition according to Claim 1.

4. wherein the diol contains 1,4 - butanediol, the aromatic dicarboxylic acid contains terephthalic acid or dimethyl terephthalate, and the aliphatic dicarboxylic acid contains adipic acid, The biodegradable polyester resin composition according to Claim 1.

5. where the ratio of the hard segment is about 0.2 to about 0.3, and the ratio of the hard segment is the ratio of the diol that binds between the aromatic dicarboxylic acid and the aromatic dicarboxylic acid among the diols. The biodegradable polyester resin composition according to Claim 1.

6. where the ratio of the soft segment is about 0.21 to about 0.31, and 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. The biodegradable polyester resin composition according to Claim 5.

7. where the ratio of the soft segment is even greater than the ratio of the hard segment, The biodegradable polyester resin composition according to Claim 6.

8. where the biodegradation degree after 9 weeks is 85% or more, and the biodegradation degree after 9 weeks is measured by the following measurement method, The biodegradable polyester resin composition according to Claim 1. [Measurement Method] The biodegradation degree after 9 weeks is the rate of decrease in the molecular weight of the biodegradable polyester resin composition with respect to the initial value when the biodegradable polyester resin composition is placed for 9 weeks under composting conditions, a temperature of 60 °C, and a humidity of 90%.

9. where the biodegradation degree per aliphatic carboxylic acid after 9 weeks is 1.7 or more, and the biodegradation degree per aliphatic carboxylic acid after 9 weeks is the value obtained by dividing the biodegradation degree after 9 weeks by the mole percentage of the aliphatic carboxylic acid among all the dicarboxylic acids. The biodegradable polyester resin composition according to Claim 8.

10. A biodegradable polyester resin composition comprising a polyester resin containing a diol, an aromatic dicarboxylic acid and an aliphatic dicarboxylic acid, wherein the proportion of the hard segment of the polyester resin is 0.2 to 0.3, and the proportion of the hard segment is the proportion of the diol that binds between the aromatic dicarboxylic acid and the aromatic dicarboxylic acid among the diols, A biodegradable polyester resin composition.

11. wherein the proportion of the hard segment is 0.21 to 0.28, The biodegradable polyester resin composition according to claim 10.

12. wherein the proportion of the hard segment is 0.22 to 0.27, The biodegradable polyester resin composition according to claim 10.

13. The biodegradable polyester resin composition according to claim 10, wherein the tensile strength measured by the following measurement method is 40 MPa to 60 MPa.

12. [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.

14. The elongation at break of the polyester sheet is about 800% to about 1100%, The biodegradable polyester resin composition according to claim 13.

15. A biodegradable molded article comprising a polyester resin containing a diol, an aromatic dicarboxylic acid and an aliphatic dicarboxylic acid, wherein the proportion of the alternation of the polyester resin is 0.37 to 0.59, and the proportion of the alternation is the proportion of the diol that binds between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid among the diols, A biodegradable molded article.

16. wherein the proportion of the hard segment is about 0.2 to about 0.3, and the proportion of the hard segment is the proportion of the diol that binds between the aromatic dicarboxylic acid and the aromatic dicarboxylic acid among the diols, The biodegradable molded article according to claim 15.

17. wherein the proportion of the soft segment is about 0.21 to about 0.31, and the proportion of the soft segment is the proportion of the diol that binds between the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid among the diols, The biodegradable molded article according to claim 16.

18. The biodegradable molded article according to claim 15, wherein the tensile strength is 40 MPa to 60 MPa.

19. The elongation at break is about 800% to about 1100%, ​ The biodegradable molded article according to claim 18.

20. The diol includes 1,4-butanediol, the aromatic dicarboxylic acid includes terephthalic acid or dimethyl terephthalate, and the aliphatic dicarboxylic acid includes adipic acid. The biodegradable molded article according to claim 15.

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