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

Abstract

Examples include a polyester resin containing a diol, an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid, wherein the soft segment ratio of the polyester resin is 0.21 to 0.29, and the soft segment ratio is the ratio of the diol bonded between the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid.

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 technology]

[0002] In recent years, as concerns about environmental issues have grown, solutions are being sought for the disposal of various household products, particularly disposable products. Specifically, polymer materials are inexpensive and have excellent processability and other properties, and are widely used to manufacture various products such as films, fibers, packaging materials, bottles, and containers. However, when used products reach the end of their lifespan, they emit harmful substances when incinerated, and depending on the type, they can take hundreds of years to completely decompose naturally.

[0003] To overcome the limitations of these polymers, active research is being conducted into biodegradable polymers that decompose quickly. Biodegradable polymers in use include polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), and polybutylene succinate (PBS).

[0004] These biodegradable polyester resin compositions are disclosed in Korean Patent Publication No. 2012-0103158, for example. Summary of the Invention [Problem to be solved by the invention]

[0005] The examples are intended to provide a biodegradable polyester resin composition having improved biodegradability and suitable flexibility, a biodegradable polyester film containing the same, and a biodegradable molded article containing the same. [Means for solving the problem]

[0006] The biodegradable polyester resin composition according to the embodiment includes a polyester resin containing a diol, an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid, and the soft segment ratio of the polyester resin is 0.21 to 0.31, and the soft segment ratio is the ratio of the diol bonded between the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid among the diols.

[0007] In the biodegradable polyester resin composition according to one embodiment, the ratio of the soft segment may be 0.21 to 0.28.

[0008] In the biodegradable polyester resin composition according to one embodiment, the ratio of the soft segment may be 0.22 to 0.27.

[0009] In one embodiment, the diol may include 1,4-butanediol, the aromatic dicarboxylic acid may include terephthalic acid or dimethyl terephthalate, and the aliphatic dicarboxylic acid may include adipic acid.

[0010] In one embodiment, the ratio of the diol bonded between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid may be 0.4 to 0.59.

[0011] The crystallization temperature of the polyester resin composition according to an embodiment may be 38°C to 58°C.

[0012] The polyester resin composition according to an embodiment may have a melting point of 70°C to 130°C, and a glass transition temperature of -50°C to -15°C.

[0013] In the biodegradable polyester resin composition according to one embodiment, the Young's modulus measured by the following measurement method may be 25 MPa to 60 MPa.

[0014] [Measurement method] The biodegradable polyester resin composition is dried at a temperature of 80°C, placed in a stainless steel frame, and compressed at a temperature of 210°C and a pressure of 10 MPa for 3 minutes to produce a polyester sheet having a thickness of 300 μm. The Young's modulus of the polyester sheet is measured at room temperature.

[0015] In the biodegradable polyester resin composition according to one embodiment, the breaking elongation measured by the following measuring method may be about 800% to about 1100%.

[0016] [Measurement method] The breaking elongation of the polyester sheet is measured at room temperature.

[0017] The biodegradable polyester film according to the embodiment includes a polyester resin containing a diol, an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid, and the soft segment ratio of the polyester resin is 0.21 to 0.31, and the soft segment ratio is the ratio of the diol bonded between the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid.

[0018] In the biodegradable polyester film according to one embodiment, the ratio of the soft segment may be 0.21 to 0.28.

[0019] In the biodegradable polyester film according to one embodiment, the ratio of the soft segment may be 0.25 to 0.28.

[0020] In the biodegradable polyester film according to one embodiment, the ratio of the diol bonded between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid may be 0.4 to 0.59.

[0021] In the biodegradable polyester film according to one embodiment, the ratio of the diol bonded between the aromatic dicarboxylic acid and the aromatic dicarboxylic acid to the diol may be 0.21 to 0.29.

[0022] In the biodegradable polyester film according to an embodiment, the crystallization temperature may be 38°C to 58°C.

[0023] In one embodiment, the biodegradable polyester film may have a melting point of 70°C to 130°C and a glass transition temperature of -50°C to -15°C.

[0024] In the biodegradable polyester film according to an embodiment, the Young's modulus may be 25 MPa to 60 MPa.

[0025] The biodegradable molded article according to the embodiment includes a polyester resin containing a diol, an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid, and the soft segment ratio of the polyester resin is 0.21 to 0.31, and the soft segment ratio is the ratio of the diol bonded between the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid.

[0026] In one embodiment, the biodegradable molded article is a biodegradable molded article in which the ratio of the diol bonded between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid is 0.4 to 0.59.

[0027] In the biodegradable molded article according to one embodiment, the ratio of the diol bonded between the aromatic dicarboxylic acid and the aromatic dicarboxylic acid to the diol may be 0.21 to 0.29.

[0028] In the biodegradable molded article according to one embodiment, the Young's modulus may be 25 MPa to 60 MPa. [Effects of the Invention]

[0029] The biodegradable polyester resin composition according to the embodiment includes a polyester resin having an appropriate soft segment ratio. The content of the diol bonded between the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid may be appropriate.

[0030] Therefore, the biodegradable polyester resin may appropriately contain the aliphatic dicarboxylic acid and a bond structure in which the aliphatic dicarboxylic acid is bonded to the diol, and therefore the biodegradable polyester resin may have appropriate crystal properties, and the biodegradable polyester resin composition according to the embodiment may have appropriate thermal and mechanical properties.

[0031] In particular, since the biodegradable polyester resin has a soft segment ratio within the above range, the biodegradable polyester resin composition according to the embodiment may have an appropriate Young's modulus, an appropriate glass transition temperature, an appropriate crystallization temperature, and an appropriate melting point.

[0032] In particular, the biodegradable polyester resin composition according to the embodiment may have appropriate flexibility due to the molecular structure described above, and may also be prevented from becoming sticky due to the molecular structure described above.

[0033] In addition, since the biodegradable polyester resin contains an appropriate amount of the structure in which the diol is bonded between the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid, the biodegradable polyester resin composition according to the embodiment may simultaneously have an appropriate degree of hydrolysis and an improved degree of biodegradation.

[0034] Therefore, the biodegradable polyester resin compositions according to the examples have appropriate flexibility during the period of actual use, and can be easily biodegraded after use.

[0035] In particular, the biodegradable polyester resin composition according to the embodiment can be effectively used for packaging films, etc. That is, films made from the biodegradable polyester resin composition according to the embodiment can be used for general purposes such as packaging. In this case, the biodegradable polyester resin composition according to the embodiment can maintain appropriate flexibility and chemical properties throughout the normal usage period of the user.

[0036] In addition, since the biodegradable polyester resin composition according to the embodiment has a high degree of biodegradability, the film manufactured using the biodegradable polyester resin composition according to the embodiment can be easily biodegraded when disposed of after use. [Brief explanation of the drawings]

[0037] [Figure 1] 1 is a schematic diagram showing an apparatus for producing a polyester resin composition according to an example. [Figure 2] FIG. 2 is a diagram showing an example of a biodegradable molded article formed from the POLYESTE resin composition according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0038] The present invention will be described in detail below with reference to specific examples. The specific examples are not limited to the contents of the disclosure below, and may be modified in various forms without departing from the spirit of the invention.

[0039] In this specification, when a part is described as "comprising" a certain component, this does not mean that it excludes other components, and that it may further include other components, unless otherwise specified.

[0040] Furthermore, all numerical ranges indicating physical properties, dimensions, etc. of components described in this specification should be understood to be modified by the term "about" unless otherwise specified.

[0041] In this specification, terms such as first, second, primary, and secondary are used to describe various components, and the components are not limited by these terms. These terms are used only to distinguish one component from another.

[0042] In the description of this embodiment, the ppm content units may be based on mass.

[0043] 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.

[0044] 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.

[0045] In the description of the biodegradable polyester resin composition according to the embodiment, the diol residue can be expressed as a diol. In the biodegradable polyester resin, the dicarboxylic acid residue can be expressed as a dicarboxylic acid. The residue can also be expressed as the component.

[0046] The diol may be an aliphatic diol. The diol may be a bio-based diol. The diol may be 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, At least one selected from the group consisting of 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, may be used.

[0047] 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.

[0048] 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.

[0049] The diol may include 1,4-butanediol or a derivative thereof.

[0050] 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, and derivatives thereof.

[0051] 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.

[0052] The aromatic dicarboxylic acid may include terephthalic acid, dimethyl terephthalate, or a derivative thereof.

[0053] 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, and derivatives thereof.

[0054] The aliphatic dicarboxylic acid may be at least one selected from the group consisting of adipic acid, succinic acid, sebacic acid, and derivatives thereof.

[0055] The aliphatic dicarboxylic acid may include adipic acid or a derivative thereof.

[0056] In the biodegradable polyester resin, the molar ratio of all diol residues including the diol to all 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 all diol residues to all dicarboxylic acid residues may be about 1:0.95 to about 1:1.05.

[0057] 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.

[0058] The biodegradable polyester resin may contain diol residues derived from 1,4-butanediol at a content of about 90 mol% or more, based on the total diols. The biodegradable polyester resin may contain diol residues derived from 1,4-butanediol at a content of about 95 mol% or more, based on the total diols. The biodegradable polyester resin may contain diol residues derived from 1,4-butanediol at a content of about 98 mol% or more, based on the total diols.

[0059] The biodegradable polyester resin may contain aromatic dicarboxylic acid residues derived from terephthalic acid or dimethyl terephthalate in an amount of about 30 mol % to about 70 mol % based on the total dicarboxylic acids. The biodegradable polyester resin may contain aromatic dicarboxylic acid residues derived from terephthalic acid or dimethyl terephthalate in an amount of about 35 mol % to about 65 mol % based on the total dicarboxylic acids. The biodegradable polyester resin may contain dicarboxylic acid residues derived from terephthalic acid or dimethyl terephthalate in an amount of about 40 mol % to about 60 mol % based on the total dicarboxylic acids. The biodegradable polyester resin may contain aromatic dicarboxylic acid residues derived from terephthalic acid or dimethyl terephthalate in an amount of about 43 mol % to about 53 mol % based on the total dicarboxylic acids.

[0060] 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 acids. 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 acids. 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 acids. 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 acids.

[0061] The biodegradable polyester resin may include a first block and a second block, and may have a molecular structure in which the first blocks and the second blocks are alternately bonded.

[0062] The first block may include 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 include only the diol residue and the aromatic dicarboxylic acid residue. The first block may include only repeating units formed by an esterification reaction of the diol and the aromatic dicarboxylic acid. In other words, the first block may mean the sum of the repeating units of the diol and the aromatic dicarboxylic acid before the aliphatic dicarboxylic acid is bonded.

[0063] The second block may include 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 include only the diol residue and the aliphatic dicarboxylic acid residue. The second block may include only repeating units formed by an esterification reaction of the diol and the aliphatic dicarboxylic acid. In other words, the second block may refer to the sum of the repeating units of the diol and the aliphatic dicarboxylic acid before the aromatic dicarboxylic acid is bonded.

[0064] In the biodegradable polyester resin, the ratio (X / Y) of the number of the first blocks (X) to the number of the second blocks (Y) may be about 0.5 to about 1.5. In the biodegradable polyester resin, the ratio (X / Y) of the number of the first blocks (X) to the number of the second blocks (Y) may be about 0.6 to about 1.4. In the biodegradable polyester resin, the ratio (X / Y) of the number of the first blocks (X) to the number of the second blocks (Y) may be about 0.7 to about 1.3. In the biodegradable polyester resin, the ratio (X / Y) of the number of the first blocks (X) to the number of the second blocks (Y) may be about 0.75 to about 1.2. In addition, in the biodegradable polyester resin, the ratio (X / Y) of the number of the first blocks (X) to the number of the second blocks (Y) may be 0.8 to 1. The number of the first blocks may be smaller than the number of the second blocks.

[0065] The number of the first blocks may be about 30 to about 300. The number of the first blocks may be about 40 to about 250. The number of the first blocks may be about 50 to about 220. The number of the first blocks may be about 60 to about 200. The number of the first blocks may be about 70 to about 200. The number of the first blocks may be about 75 to about 200.

[0066] The number of the first blocks may vary depending on the content of the aromatic dicarboxylic acid, the molecular weight of the biodegradable polyester resin, and the degree of alternation (described below). That is, the number of the first blocks may increase as the molar ratio of the aromatic dicarboxylic acid increases, the molecular weight of the biodegradable polyester resin increases, and the degree of alternation (described below) increases.

[0067] The number of the second blocks may be about 30 to about 300. The number of the second blocks may be about 40 to about 250. The number of the second blocks may be about 50 to about 220. The number of the second blocks may be about 60 to about 200. The number of the second blocks may be about 70 to about 200. The number of the second blocks may be about 75 to about 200.

[0068] The number of the second blocks may vary depending on the content of the aliphatic dicarboxylic acid, the molecular weight of the biodegradable polyester resin, and the degree of alternation (described later). That is, the number of the first blocks may increase as the molar ratio of the aliphatic dicarboxylic acid increases, the molecular weight of the biodegradable polyester resin increases, and the degree of alternation (described later) increases.

[0069] 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 embodiment may have appropriate mechanical strength and appropriate biodegradability. Furthermore, 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 embodiment may have improved flexibility and improved rigidity. This allows the biodegradable polyester resin composition according to the embodiment to be easily used in injection molding products, etc. Furthermore, 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 embodiment may have appropriate durability to ultraviolet rays, etc., and appropriate biodegradability.

[0070] The first block may be represented by the following formula 1:

[0071] [ka]

[0072] Here, R1 may be a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, R2 may be a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, and m may be 1 to 20.

[0073] The R1 may be a substituted or unsubstituted phenylene group, and the R2 may be a butylene group.

[0074] The second block may be represented by the following formula 2:

[0075] [ka]

[0076] 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.

[0077] The R3 and R4 may be a butylene group.

[0078] The biodegradable polyester resin may have a structure in which the first blocks and the second blocks are alternately bonded to each other. The biodegradable polyester resin may be represented by the following Chemical Formula 3.

[0079] [ka]

[0080] Here, R1 may be a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, R2 may be a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, and m may be an integer of 1 to 20. Furthermore, R3 and R4 may each independently be a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, and n may be an integer of 1 to 20.

[0081] The diol residue may include a residue of 1,4-butanediol or a derivative thereof, the aromatic dicarboxylic acid residue may include 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.

[0082] For example, the biodegradable polyester resin may include a first block that includes residues of 1,4-butanediol or a derivative thereof and residues of terephthalic acid or a derivative thereof.

[0083] 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.

[0084] The biodegradable polyester resin may include a second block including residues of 1,4-butanediol or a derivative thereof and residues of adipic acid or a derivative thereof.

[0085] 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.

[0086] A biodegradable polyester resin according to an embodiment of the present invention may include a first block including a residue of 1,4-butanediol or a derivative thereof and a residue of terephthalic acid or a derivative thereof; and a second block including a residue of 1,4-butanediol or a derivative thereof and a residue of adipic acid or a derivative thereof.

[0087] The first block may be represented by the following Chemical Formula 4, and the second block may be represented by the following Chemical Formula 5.

[0088] [ka]

[0089] Here, the m may be 1 to 20.

[0090] [ka]

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

[0092] The biodegradable polyester resin may be one represented by the following chemical formula 6.

[0093] [ka]

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

[0095] When the first block and the second block satisfy the above-mentioned configuration, it may be more advantageous to provide a biodegradable polyester sheet, film, or molded product having excellent biodegradability and water dispersibility, and improved physical properties.

[0096] Furthermore, 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 embodiment may have appropriate mechanical properties and appropriate UV resistance.

[0097] Since the first block and the second block have the above-mentioned characteristics, the mechanical properties of the biodegradable polyester resin composition according to the embodiment can be improved.

[0098] Since the first block and the second block have the above-described characteristics, the biodegradable polyester resin composition according to the embodiment may have appropriate UV resistance properties.

[0099] Since the first block and the second block have the above-mentioned characteristics, the biodegradable polyester resin composition according to the embodiment may have an appropriate biodegradation rate.

[0100] Since the first block and the second block have the above-mentioned characteristics, the biodegradable polyester resin composition according to the embodiment may have an appropriate hydrolysis rate.

[0101] The biodegradable polyester resin may include the following bond structures 1 to 3.

[0102] [Bond structure 1] -Aromatic dicarboxylic acid-Diol-Aliphatic dicarboxylic acid- [Bond structure 2] -Aromatic dicarboxylic acid-Diol-Aromatic dicarboxylic acid- [Bond structure 3] -Aliphatic dicarboxylic acid-Diol-Aliphatic dicarboxylic acid-

[0103] The diol contained in the bonding structure 1 is bonded 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 bonding structure 1 can be directly esterified to the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid.

[0104] In addition, the diol contained in the bonding structure 2 is bonded 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 bonding structure 2 can be directly esterified to the aromatic dicarboxylic acid and the aromatic dicarboxylic acid between the aromatic dicarboxylic acid and the aromatic dicarboxylic acid.

[0105] In addition, the diol contained in the bonding structure 3 is bonded 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 bonding structure 3 can be directly esterified to the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid between the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid.

[0106] In the biodegradable polyester resin, the bond structure 1 may be represented by the following chemical formula 7.

[0107] [ka]

[0108] 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.

[0109] In the biodegradable polyester resin, the bond structure 2 may be represented by the following chemical formula 8.

[0110] [ka]

[0111] Similarly, the R1 is a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, and the R2 is a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms.

[0112] In the biodegradable polyester resin, the bond structure 3 may be represented by the following Chemical Formula 9.

[0113] [ka]

[0114] The R2 is a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, and the R3 is a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms.

[0115] The bond structure 1 may also be represented by the following chemical formula 10.

[0116] [ka]

[0117] The bond structure 2 may be represented by the following chemical formula 11.

[0118] [ka]

[0119] The bond structure 3 may be represented by the following formula 12.

[0120] [ka]

[0121] The biodegradable polyester resin has an alternating ratio.

[0122] The alternation ratio is the ratio of the diol bonded between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid among the diols. That is, the alternation ratio may be the ratio of the diol contained in the bond structure 1 among the diols. The alternation ratio may be a value obtained by dividing the number of moles of the diol contained in the bond structure 1 by the sum of the number of moles of the diol contained in the bond structure 1, the number of moles of the diol contained in the bond structure 2, and the number of moles of the diol contained in the bond structure 3.

[0123] That is, the alternating ratio may be a ratio of diols in which two kinds of diols out of all diols are bonded between dicarboxylic acids.

[0124] The alternation rate can be calculated using the following formula 1.

[0125] [Formula 1] JPEG2025525702000014.jpg20128

[0126] Here, DM1 is the molar ratio of the diol contained in the bonding structure 1, DM2 is the molar ratio of the diol contained in the bonding structure 2, and DM3 is the molar ratio of the diol contained in the bonding structure 3.

[0127] In the biodegradable polyester resin, the alternation ratio may be about 0.3 to about 0.7. In the biodegradable polyester resin, the alternation ratio may be about 0.37 to about 0.59. In the biodegradable polyester resin, the alternation ratio may be about 0.4 to about 0.56. In the biodegradable polyester resin, the alternation ratio may be about 0.45 to about 0.53.

[0128] The biodegradable polyester resin also contains a proportion of hard segments.

[0129] The ratio of the hard segment is the ratio of the diol bonded between the aromatic dicarboxylic acid and the aromatic dicarboxylic acid to the diol.

[0130] The ratio of the hard segment may be a molar ratio of the diol contained in the bond structure 2 to the total diols. The ratio of the hard segment may be a value obtained by dividing the number of moles of the diol contained in the bond structure 2 by the sum of the number of moles of the diol contained in the bond structure 1, the number of moles of the diol contained in the bond structure 2, and the number of moles of the diol contained in the bond structure 3.

[0131] The ratio of the hard segment may be expressed by the following formula 2.

[0132] [Formula 2] JPEG2025525702000015.jpg20139

[0133] Here, DM1 is the molar ratio of the diol contained in the bonding structure 1, DM2 is the molar ratio of the diol contained in the bonding structure 2, and DM3 is the molar ratio of the diol contained in the bonding structure 3.

[0134] 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.

[0135] The biodegradable polyester resin composition also contains a soft segment.

[0136] The ratio of the soft segment is the ratio of the diol bonded between the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid, among the diols.

[0137] The ratio of the soft segment may be a molar ratio of the diol contained in the bond structure 3 to 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 bond structure 3 by the sum of the number of moles of the diol contained in the bond structure 1, the number of moles of the diol contained in the bond structure 2, and the number of moles of the diol contained in the bond structure 3.

[0138] The soft segment ratio may be expressed by the following formula 3.

[0139] [Formula 3] JPEG2025525702000016.jpg20139

[0140] Here, DM1 is the molar ratio of the diol contained in the bonding structure 1, DM2 is the molar ratio of the diol contained in the bonding structure 2, and DM3 is the molar ratio of the diol contained in the bonding structure 3.

[0141] The ratio of the soft segments may be about 0.19 to about 0.29. The ratio of the soft segments may be about 0.21 to about 0.29. The ratio of the soft segments may be about 0.22 to about 0.29. The ratio of the hard segments may be about 0.21 to about 0.28. The ratio of the soft segments may be about 0.22 to about 0.28. The ratio of the soft segments may be about 0.25 to about 0.28.

[0142] The proportion of the soft segment may be even greater than the proportion of the hard segment.

[0143] 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.

[0144] The alternation ratio, the hard segment ratio, and the soft segment ratio can be measured by nuclear magnetic resonance spectroscopy. The biodegradable polyester resin composition according to the embodiment is dissolved in a solvent such as CDCl3 and measured at room temperature by a nuclear magnetic resonance (NMR) device. 1 H-NMR and / or 13 It can be analyzed by C-NMR analysis.

[0145] 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 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.

[0146] 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, analysis of the biodegradable polyester resin by nuclear magnetic resonance spectroscopy may include a peak derived from the diol of Bond Structure 1, a peak derived from the diol of Bond Structure 2, and a peak derived from Bond Structure 3, all at about 3.5 ppm to about 4.6 ppm.

[0147] The first, second, third, and fourth peaks may be defined in the range of about 3.5 ppm to about 4.6 ppm, in order from highest to lowest ppm. Furthermore, the first, second, third, and fourth peaks may be defined in the range of about -3.4 ppm to about -4.3 ppm, in order from highest to lowest ppm, based on the ppm of the ninth peak. Here, the first peak may be derived from the diol contained in the second bonding unit, the second and third peaks 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.

[0148] Furthermore, the analysis of the biodegradable polyester resin by the nuclear magnetic resonance spectroscopy may also include a peak derived from the diol of the above-mentioned bond structure 1, a peak derived from the diol of the above-mentioned bond structure 2, and a peak derived from the above-mentioned bond structure 3, even at about 1.0 ppm to about 2.5 ppm.

[0149] The tenth peak, the fifth peak, the sixth peak, the seventh peak, the eighth peak, and the eleventh peak may be defined in order from high ppm to low ppm within a range of about 1.0 ppm to about 2.5 ppm. The fifth peak, the sixth peak, the seventh peak, the eighth peak, and the eleventh peak may be defined in order from high ppm to low ppm within a range of about -6.0 ppm to about -6.7 ppm based on the ppm of the ninth peak. In this case, the fifth peak may be derived from the diol contained in the second bonding unit, the sixth peak and the seventh peak may be derived from the diol contained in the first bonding unit, and the eighth peak may be derived from the diol contained in the third bonding unit.

[0150] Furthermore, the ninth peak can be formed in the range of about 7.5 ppm to about 8.5 ppm. The ninth peak may be derived from the aromatic dicarboxylic acid. The ninth peak may be derived from an aromatic ring contained in the aromatic dicarboxylic acid. The ninth peak may be derived from an aromatic ring contained in the terephthalic acid or dimethyl terephthalate.

[0151] The tenth and eleventh peaks may be derived from the aliphatic dicarboxylic acid. The tenth and eleventh peaks may be derived from the adipic acid.

[0152] The first peak may be located at approximately -3.6 ppm to approximately -3.68 ppm based on the ppm of the ninth peak. The second peak may be located at approximately -3.69 ppm to approximately -3.75 ppm based on the ppm of the ninth peak. The third peak may be located at approximately -3.9 ppm to approximately -3.97 ppm based on the ppm of the ninth peak. The fourth peak may be located at approximately -3.98 ppm to approximately -4.1 ppm based on the ppm of the ninth peak. The fifth peak may be located at approximately -6.0 ppm to approximately -6.19 ppm based on the ppm of the ninth peak. The sixth peak may be located at approximately -6.2 ppm to approximately -6.26 ppm based on the ppm of the ninth peak. The seventh peak may be located at approximately -6.27 ppm to approximately -6.34 ppm relative to the ppm of the ninth peak. The eighth peak may be located at approximately -6.35 ppm to approximately -6.42 ppm relative to the ppm of the ninth peak. The tenth peak may be located at approximately -5.6 ppm to approximately -5.8 ppm relative to the ppm of the ninth peak. The eleventh peak may be located at approximately -6.421 ppm to approximately -6.5 ppm relative to the ppm of the ninth peak. The positions of the ninth peak relative to ppm may be the positions of each peak when the position of the ninth peak is set to 0 ppm.

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

[0154] In addition, 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 may 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 may be determined relatively.

[0155] The alternation ratio can be derived from Equation 4 or Equation 5 below.

[0156] [Formula 4] JPEG2025525702000017.jpg19128

[0157] 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.

[0158] [Formula 5] JPEG2025525702000018.jpg19128

[0159] 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.

[0160] The ratio of the hard segment can be calculated from the following Equation 6 or Equation 7.

[0161] [Formula 6] JPEG2025525702000019.jpg20147

[0162] 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.

[0163] [Formula 7] JPEG2025525702000020.jpg20147

[0164] 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.

[0165] The soft segment ratio can be calculated from the following Equation 8 or 9.

[0166] [Formula 8] JPEG2025525702000021.jpg20145

[0167] 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.

[0168] [Formula 9] JPEG2025525702000022.jpg20145

[0169] 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.

[0170] The area of the first peak may be about 0.35 to about 0.6. The area of the first peak may be about 0.4 to about 0.55. The area of the first peak may be about 0.43 to about 0.5. The area of the first peak may be about 0.43 to about 0.52. The area of the first peak may be about 0.45 to about 0.49.

[0171] The area of the second peak may be about 0.37 to about 0.57. The area of the second peak may be about 0.41 to about 0.54. The area of the second peak may be about 0.45 to about 0.53. The area of the second peak may be about 0.45 to about 0.55. The area of the second peak may be about 0.47 to about 0.53.

[0172] The area of the third peak may be about 0.37 to about 0.57. The area of the third peak may be about 0.41 to about 0.54. The area of the third peak may be about 0.45 to about 0.53. The area of the third peak may be about 0.45 to about 0.55. The area of the third peak may be about 0.47 to about 0.53.

[0173] The area of the fourth peak may be about 0.4 to 0.7. The area of the fourth peak may be about 0.45 to about 0.65. The area of the fourth peak may be about 0.48 to about 0.6. The area of the fourth peak may be about 0.48 to 0.60. The area of the fourth peak may be about 0.50 to about 0.58.

[0174] The area of the fifth peak may be about 0.35 to about 0.6. The area of the fifth peak may be about 0.4 to about 0.55. The area of the fifth peak may be 0.43 to about 0.53. The area of the fifth peak may be about 0.43 to about 0.52. The area of the fifth peak may be about 0.45 to about 0.49.

[0175] The area of the sixth peak may be about 0.35 to about 0.6. The area of the sixth peak may be about 0.4 to about 0.55. The area of the sixth peak may be 0.43 to about 0.5. The area of the sixth peak may be about 0.45 to about 0.55. The area of the sixth peak may be about 0.47 to about 0.53.

[0176] The area of the seventh peak may be about 0.41 to about 0.71. The area of the seventh peak may be about 0.45 to about 0.65. The area of the seventh peak may be about 0.48 to about 0.6. The area of the seventh peak may be about 0.45 to about 0.55. The area of the seventh peak may be about 0.47 to about 0.53.

[0177] The area of the eighth peak may be about 0.4 to about 0.7. The area of the eighth peak may be about 0.45 to about 0.65. The area of the eighth peak may be about 0.48 to about 0.6. The area of the eighth peak may be about 0.48 to 0.60. The area of the eighth peak may be about 0.50 to about 0.58.

[0178] The area of the tenth peak may be about 0.7 to about 2.5. The area of the tenth peak may be 0.75 to about 2. The area of the tenth peak may be 0.8 to about 1.5. The area of the tenth peak may be about 1.0 to about 1.15. The area of the tenth peak may be about 1.02 to about 1.13.

[0179] The area of the 11th peak may be about 0.7 to about 3.5. The area of the 11th peak may be about 0.7 to about 3. The area of the 11th peak may be 0.8 to about 2.5. The area of the 11th peak may be about 1.0 to about 1.15. The area of the 11th peak may be about 1.02 to about 1.13.

[0180] 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 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 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 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 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 total number of ester bonds based on the number of terephthalic acids.

[0181] The sum of the area of the second peak and the area of the third peak may be 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 about 0.98 to about 1.07. Here, the sum of the area of the first peak and the area of the third peak may represent the degree of extension of molecular bonds of the biodegradable polyester resin.

[0182] 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 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 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 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 about 1.15 to about 1.25. The ratio of the area of the fourth peak to the area of the first peak may refer to the ratio of soft segments to hard segments in the molecular structure of the biodegradable polyester resin. In other words, the higher the ratio of the area of the fourth peak to the area of the first peak, the softer the biodegradable polyester resin may be.

[0183] 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 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 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 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 about 1.01 to about 1.1.

[0184] 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 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 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 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 about 0.86 to about 0.94.

[0185] Furthermore, 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 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 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 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 about 0.9 to about 1.1.

[0186] Furthermore, 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 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 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 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 about 0.9 to about 1.1.

[0187] Furthermore, 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 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 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 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 about 0.9 to about 1.1.

[0188] Furthermore, 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 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 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 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 about 0.9 to about 1.1.

[0189] Since the biodegradable polyester resin has the molecular structure described above, the biodegradable polyester resin composition according to the embodiment may be more advantageous in providing a biodegradable polyester sheet, film, or molded product having excellent biodegradability and hydrodegradability, and improved physical properties.

[0190] Furthermore, since the biodegradable polyester resin has the molecular structure described above, the biodegradable polyester resin composition according to the embodiment may have appropriate mechanical properties and appropriate UV resistance.

[0191] Since the biodegradable polyester resin has the molecular structure described above, the mechanical properties of the biodegradable polyester resin composition according to the embodiment can be improved.

[0192] Since the biodegradable polyester resin has the molecular structure described above, the biodegradable polyester resin composition according to the embodiment may have suitable UV resistance properties.

[0193] Since the first block and the second block have the above-mentioned characteristics, the biodegradable polyester resin composition according to the embodiment may have an appropriate biodegradation rate.

[0194] Since the biodegradable polyester resin has the molecular structure described above, the biodegradable polyester resin composition according to the embodiment may have an appropriate hydrolysis rate.

[0195] The biodegradable polyester resin may further contain a branching agent. The branching agent may contain a trivalent or higher alcohol and / or a trivalent 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 in the biodegradable polyester resin as part of its molecular structure.

[0196] The trihydric or higher alcohol may be at least one selected from the group consisting of glycerol, pentaerythritol, and trimethylolpropane.

[0197] The trivalent or higher carboxylic acid may be methane tricarboxylic acid, ethane tricarboxylic 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. At least one selected from the group consisting of:

[0198] The branching agent may be contained in the biodegradable polyester resin in an amount of about 0.1 wt% to about 5 wt% based on the total amount of the biodegradable polyester resin. The branching agent may be contained in the biodegradable polyester resin in an amount of about 0.1 wt% to about 3 wt% based on the total amount of the biodegradable polyester resin. The branching agent may be contained in the biodegradable polyester resin in an amount of about 0.1 wt% to about 1 wt% based on the total amount of the biodegradable polyester resin.

[0199] Since the biodegradable polyester resin contains the branching agent in the above range, the biodegradable polyester resin composition according to the embodiment may have suitable mechanical properties and suitable biodegradability.

[0200] The biodegradable polyester resin composition according to the embodiment may contain the biodegradable resin in an amount 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 an amount 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 an amount 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 an amount 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 an amount 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 an amount 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 an amount of about 99 wt% or more based on the weight of the entire composition. The maximum amount 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.

[0201] The biodegradable polyester resin composition according to the embodiment may further include a reinforcing material. The reinforcing material may improve the mechanical properties of the biodegradable polyester resin composition according to the embodiment and the film or molded article produced therefrom. In addition, the reinforcing material may adjust the deformation characteristics of the biodegradable polyester resin composition according to the embodiment due to ultraviolet light. In addition, the reinforcing material may adjust the hydrolysis characteristics of the biodegradable polyester resin composition according to the embodiment. In addition, the reinforcing material may adjust the biodegradability of the biodegradable polyester resin according to the embodiment.

[0202] The reinforcing material may be derived from biomass, may be fibers made of organic material, or may be nanocellulose.

[0203] The nanocellulose may be one or more selected from the group consisting of nanocrystalline cellulose, cellulose nanofiber, microfibrillated cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, cellulose acetate, methyl cellulose, ethyl cellulose, propyl cellulose, butyl cellulose, pentyl cellulose, hexyl cellulose, and cyclohexyl cellulose.

[0204] The nanocrystalline cellulose may contain an ionically bonded metal. The nanocrystalline cellulose may contain elemental sodium. The nanocrystalline cellulose may also contain a sulfate. The nanocrystalline cellulose may also contain a carboxylate. The nanocrystalline cellulose may be cellulose hydrogen sulfate sodium salt.

[0205] The nanocellulose may be represented by the following formula 13:

[0206] [ka]

[0207] Here, the x may be 1 to 35, and the y may be 1 to 10. The x may be 15 to 35, and the y may be 1 to 10.

[0208] The nanocellulose is about 200 m 2 / g~about 600m 2 The nanocellulose may have a specific surface area of about 250 m / g. 2 / g~about 500m 2 / g specific surface area.

[0209] 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.

[0210] 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%.

[0211] The nanocellulose may have an average diameter of about 0.5 nm to about 10 nm, about 1 nm to about 8 nm, or about 1.5 nm to about 7 nm.

[0212] The nanocellulose may have an average length of about 20 nm to about 300 nm, about 30 nm to about 180 nm, or about 35 nm to about 150 nm.

[0213] When the diameter and length of the nanocellulose satisfy the above ranges, the biodegradability and physical properties of the biodegradable polyester resin or the biodegradable polyester sheet, film, and molded product obtained using the same can be further improved.

[0214] The diameter and length of the nanocellulose can be measured by atomic force microscopy while dispersed in water.

[0215] The sulfur content of the nanocellulose may be about 0.1 wt% to about 1.2 wt% based on the total nanocrystalline cellulose.The sulfur content of the nanocrystalline cellulose may be about 0.2 wt% to about 1.1 wt% based on the total nanocellulose.

[0216] The pH of the nanocellulose may be 5 to 8. The pH of the nanocellulose may be 6 to 8.

[0217] The zeta potential of the nanocellulose may be about -25 mV to about -50 mV. The zeta potential of the nanocellulose may be about -30 mV to about -45 mV.

[0218] The nanocellulose may be contained in the biodegradable polyester resin composition according to the embodiment in an amount of about 0.01 to about 2 parts by weight, based on 100 parts by weight of the biodegradable polyester resin. The nanocellulose may be contained in the biodegradable polyester resin composition according to the embodiment in an amount of about 0.03 to about 1.5 parts by weight, based on 100 parts by weight of the biodegradable polyester resin. The nanocellulose may be contained in the biodegradable polyester resin composition according to the embodiment in an amount of about 0.04 to about 1.2 parts by weight, based on 100 parts by weight of the biodegradable polyester resin. The nanocellulose may be contained in the biodegradable polyester resin composition according to the embodiment in an amount of about 0.05 to about 1 part by weight, based on 100 parts by weight of the biodegradable polyester resin.

[0219] Because the nanocellulose has the above-mentioned characteristics, it can be uniformly dispersed in the biodegradable polyester resin composition according to the embodiment.

[0220] Because the nanocellulose has the above-mentioned characteristics, it can improve the mechanical properties of the biodegradable polyester resin composition according to the embodiment.

[0221] In addition, the nanocellulose functions as a crystal nucleating agent, thereby increasing the crystallization rate of the biodegradable polyester resin composition according to the embodiment, and thus increasing the crystallization temperature of the biodegradable polyester resin composition according to the embodiment.

[0222] Since the nanocellulose has the above-mentioned characteristics, the biodegradable polyester resin composition according to the embodiment may have appropriate UV resistance properties.

[0223] Since the nanocellulose has the above-mentioned characteristics, the biodegradable polyester resin composition according to the embodiment may have an appropriate biodegradation rate.

[0224] Since the nanocellulose has the above-mentioned characteristics, the biodegradable polyester resin composition according to the embodiment may have an appropriate hydrolysis rate.

[0225] The biodegradable polyester resin composition according to the embodiment may contain a metal salt.

[0226] 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 embodiment. 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 embodiment. 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 embodiment. 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 embodiment.

[0227] The metal salt may be at least one selected from the group consisting of nitrates, sulfates, hydrochlorides, carboxylates, etc. The metal salt may be at least one selected from the group consisting of titanium salts, silicon salts, sodium salts, calcium salts, potassium salts, magnesium salts, copper salts, iron salts, aluminum salts, silver salts, etc. The metal salt may be at least one selected from the group consisting of magnesium acetate, calcium acetate, potassium acetate, copper nitrate, silver nitrate, sodium nitrate, etc.

[0228] The metal salt may include 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).

[0229] The metal salt may be selected from the group consisting of acetate, nitrate, nitride, sulfide, sulfate, sulfoxide, hydroxide, hydrate, chloride, chlorinate, and bromide.

[0230] The biodegradable polyester resin composition according to the embodiment contains the metal salt in the above content, so that the hydrolysis rate and biodegradation rate can be appropriately adjusted.

[0231] The biodegradable polyester resin composition according to the embodiment may further contain a hydrolysis stabilizer.

[0232] The hydrolysis stabilizer may be at least one selected from silicon-based compounds such as silane, silazane, or siloxane.

[0233] The hydrolysis stabilizer may include an alkoxysilane. The hydrolysis stabilizer may include trimethoxysilane and / or triethoxysilane. The hydrolysis stabilizer may include an alkoxysilane containing an epoxy group. The hydrolysis stabilizer may include at least one selected from the group consisting of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyl methyldimethoxysilane, 3-glycidoxypropyl trimethoxysilane, 3-glycidoxypropyl methyldiethoxysilane, and 3-glycidoxypropyl triethoxysilane.

[0234] The hydrolysis stabilizer may be contained in the biodegradable polyester resin composition according to the embodiment in an amount of about 1 ppm to about 10,000 ppm. The hydrolysis stabilizer may be contained in the biodegradable polyester resin composition according to the embodiment in an amount of about 1 ppm to about 1,000 ppm. The hydrolysis stabilizer may be contained in the biodegradable polyester resin composition according to the embodiment in an amount of about 5 ppm to 500 ppm. The hydrolysis stabilizer may be contained in the biodegradable polyester resin composition according to the embodiment in an amount of about 10 ppm to 300 ppm.

[0235] The hydrolysis stabilizer may be bonded to the biodegradable polyester resin. The hydrolysis stabilizer may be chemically bonded to the biodegradable polyester resin. The hydrolysis stabilizer may be chemically bonded to a polymer contained in the biodegradable polyester resin. The hydrolysis stabilizer may couple the polymers contained in the biodegradable polyester resin to each other.

[0236] The biodegradable polyester resin composition according to the embodiment may have suitable hydrolysis resistance because it contains the hydrolysis stabilizer in the range described above. In particular, the biodegradable polyester resin according to the embodiment may have suitable initial hydrolysis resistance and improved biodegradability because it contains the hydrolysis stabilizer in the range described above.

[0237] Accordingly, the biodegradable polyester resin composition according to the embodiment may contain silicon element. The biodegradable polyester resin composition according to the embodiment may contain silicon element in a content of about 0.1 ppm to about 100 ppm. The biodegradable polyester resin composition according to the embodiment may contain silicon element in a content of about 0.1 ppm to about 50 ppm. The biodegradable polyester resin composition according to the embodiment may contain silicon element in a content of about 0.1 ppm to about 20 ppm.

[0238] In addition, the hydrolysis stabilizer may react with terminal carboxyl groups or unreacted carboxyl groups, so that the biodegradable polyester resin composition according to the embodiment may have a low acid value.

[0239] In addition, the hydrolysis stabilizer couples the polymers contained in the biodegradable polyester resin, thereby increasing the proportion of high molecular weight polymers in the biodegradable polyester resin composition according to the embodiment, thereby improving the mechanical properties of the biodegradable polyester resin composition according to the embodiment.

[0240] The biodegradable polyester resin composition according to the embodiment may further contain a chain extender.

[0241] The chain extender may include an isocyanate.

[0242] The chain extender may be at least one selected from the group consisting of monofunctional isocyanates and polyfunctional isocyanates.

[0243] The chain extender may be at least one selected from the group consisting of tolylene 2,4-diisocyanate, tolylene 2,6-diisocyanate, diphenylmethane 4,4′-diisocyanate, and 2,4′-diisocyanate, naphthalene 1,5-diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, isophorone diisocyanate, and methylenebis(4-isocyanatocyclohexane).

[0244] The chain extender may include a triisocyanate. The chain extender may include tri(4-isocyanatophenyl)methane.

[0245] The chain extender may include an acrylic polymer. The acrylic polymer may include an acrylic group. The acrylic group may be bonded to a main chain as a side chain. The acrylic polymer may include an epoxy group. The epoxy group may be bonded to the main chain as a side chain.

[0246] The chain extender may include a styrene-based copolymer. The chain extender may include a styrene-based glycidyl acrylate.

[0247] 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 an end of a polymer contained in the biodegradable polyester resin. Furthermore, the chain extender may be bonded to an end of three polymers contained in the biodegradable polyester resin.

[0248] The chain extender may be contained in the biodegradable polyester resin composition according to the embodiment in an amount of about 0.1 wt% to about 10 wt%. The chain extender may be contained in the biodegradable polyester resin composition according to the embodiment in an amount of about 0.2 wt% to about 8 wt%. The chain extender may be contained in the biodegradable polyester resin composition according to the embodiment in an amount of about 0.3 wt% to about 7 wt%.

[0249] When the biodegradable polyester resin composition according to the embodiment contains the chain extender in the above range, it may have appropriate hydrolysis resistance and appropriate biodegradability.

[0250] In addition, the chain extender may react with the terminal carboxyl group or the unreacted carboxyl group, so that the biodegradable polyester resin composition according to the embodiment may have a low acid value.

[0251] In addition, the chain extender couples the polymers contained in the biodegradable polyester resin, thereby increasing the proportion of high molecular weight polymers in the biodegradable polyester resin composition according to the embodiment, thereby improving the mechanical properties of the biodegradable polyester resin composition according to the embodiment.

[0252] The biodegradable polyester resin composition according to the embodiment may contain an oligomer, and the molecular weight of the oligomer may be about 400 to about 1,300.

[0253] The oligomer may be contained in the biodegradable polyester resin composition according to the embodiment in an amount of about 3,000 ppm to about 30,000 ppm based on the total resin composition. The oligomer may be contained in the biodegradable polyester resin composition according to the embodiment in an amount of about 5,000 ppm to about 20,000 ppm based on the total resin composition. The oligomer may be contained in the biodegradable polyester resin composition according to the embodiment in an amount of about 5,000 ppm to about 15,000 ppm based on the total resin composition. The oligomer may be contained in the biodegradable polyester resin composition according to the embodiment in an amount of about 7,000 ppm to about 15,000 ppm based on the total resin composition.

[0254] The oligomer may be a reaction product of at least two 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.

[0255] The oligomer may include an oligomer having a higher molar ratio of the aliphatic dicarboxylic acid than the aromatic dicarboxylic acid, and the proportion of the oligomer having a relatively higher aliphatic dicarboxylic acid may be higher than the proportion of the oligomer having a relatively higher aromatic dicarboxylic acid.

[0256] The oligomer can appropriately adjust the degree of hydrolysis of the biodegradable polyester resin composition according to the embodiment. The oligomer may be a hydrolysis regulator that appropriately adjusts the degree of hydrolysis of the biodegradable polyester resin composition according to the embodiment.

[0257] In addition, the oligomer can appropriately adjust the biodegradability of the biodegradable polyester resin composition according to the embodiment. The oligomer may be a biodegradation regulator that appropriately adjusts the biodegradability of the biodegradable polyester resin composition according to the embodiment.

[0258] The biodegradable polyester resin composition according to the embodiment may contain a thermal stabilizer. The thermal stabilizer may be a phosphorus-based thermal stabilizer.

[0259] The heat stabilizer may be at least one selected from the group consisting of an amine-based high-temperature heat stabilizer such as tetraethylenepentamine, triethylphosphonoacetate, phosphoric acid, phosphorous acid, polyphosphoric acid, trimethyl phosphate (TMP), triethyl phosphate, trimethyl phosphine, or triphenyl phosphine.

[0260] The heat stabilizer may be an antioxidant having an antioxidant function.

[0261] The content of the thermal stabilizer may be about 3,000 ppm or less based on the total weight of the biodegradable polyester resin. The content of the thermal 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. When the content of the thermal stabilizer satisfies the above range, degradation of the polymer due to high temperatures during the reaction process can be controlled, and the polymer end groups can be reduced, improving color. Furthermore, the thermal stabilizer can adjust the reaction rate by suppressing the activation of titanium-based catalysts, etc.

[0262] The biodegradable polyester resin composition according to the embodiment may contain an elongation improver, such as an oil such as paraffin oil, naphthenic oil, or aromatic oil, or an adipate such as dibutyl adipate, diethylhexyl adipate, dioctyl adipate, or diisopropyl adipate.

[0263] The elongation enhancer may be contained in the biodegradable polyester resin composition according to the embodiment in an amount of about 0.001 part by weight to about 1 part by weight based on 100 parts by weight of the biodegradable polyester resin. The elongation enhancer may be contained in the biodegradable polyester resin composition according to the embodiment in an amount of about 0.01 part by weight to about 1 part by weight based on 100 parts by weight of the biodegradable polyester resin.

[0264] The biodegradable polyester resin composition according to the embodiment may contain an inorganic filler, which may be at least one selected from the group consisting of calcium sulfate, barium sulfate, talc, talc 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, silicates, mica, glass fiber, and mineral fiber.

[0265] Regarding the inorganic filler, the cumulative 50% particle size (D 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.

[0266] The specific surface area of the inorganic filler is about 100 m 2 For example, the specific surface area of the inorganic filler may be about 100 m / g or more. 2 / g or more, approximately 105m 2 / g or more or about 110m 2 / g or more.

[0267] The inorganic filler may be contained in the biodegradable polyester resin composition according to the embodiment in an amount of about 3 parts by weight to about 50 parts by weight based on 100 parts by weight of the biodegradable polyester resin.The inorganic filler may be contained in the biodegradable polyester resin composition according to the embodiment in an amount of about 5 parts by weight to about 30 parts by weight based on 100 parts by weight of the biodegradable polyester resin.

[0268] The inorganic filler may be contained in an amount of about 3,000 ppm or less based on the total weight of the biodegradable polyester resin composition according to the embodiment. For example, the amount 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 embodiment, or 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.

[0269] Since the biodegradable polyester resin composition according to the embodiment contains the inorganic filler in the above content, it may have the mechanical properties, suitable UV resistance, suitable biodegradation rate, and suitable hydrolysis rate of the biodegradable polyester resin composition according to the embodiment.

[0270] The biodegradable polyester resin composition according to the embodiment may further contain two types of biodegradable polyester resins. The biodegradable polyester resin composition according to the embodiment may be a composite resin composition containing two or more types of resins, fillers, and additives.

[0271] The two types of biodegradable polyester resins may be at least one selected from the group consisting of polybutylene azelate terephthalate (PBAzT), polybutylene sebacate terephthalate (PBSeT), polybutylene succinate terephthalate (PBST), polyhydroxyalkanoate (PHA), or polylactic acid (PLA).

[0272] The two biodegradable polyester resins may be contained in the biodegradable polyester resin composition according to the embodiment in an amount of about 10 parts by weight to about 100 parts by weight, based on 100 parts by weight of the biodegradable polyester resin. The two biodegradable polyester resins may be contained in the biodegradable polyester resin composition according to the embodiment in an amount of about 10 parts by weight to about 60 parts by weight, based on 100 parts by weight of the biodegradable polyester resin. The two biodegradable polyester resins may be contained in the biodegradable polyester resin composition according to the embodiment in an amount of about 20 parts by weight to about 50 parts by weight, based on 100 parts by weight of the biodegradable polyester resin.

[0273] The two types of biodegradable polyester resins can complement the mechanical, optical, and chemical properties of the biodegradable polyester resin. The biodegradable polyester resin composition according to the embodiment contains the two types of biodegradable polyester resins in the above amounts, and therefore may have the mechanical properties, suitable UV resistance, suitable biodegradation rate, and suitable hydrolysis rate of the biodegradable polyester resin composition according to the embodiment.

[0274] In addition, the number of carboxyl end groups of the biodegradable polyester resin composition according to the embodiment may be about 50 eq / ton or less. For example, the number of carboxyl end groups of the biodegradable polyester resin according to the embodiment 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. By adjusting the number of carboxyl end groups within the above range, the biodegradable polyester resin composition according to the embodiment can prevent deterioration and achieve improved mechanical properties when extruded to form a molded product.

[0275] Furthermore, the intrinsic viscosity (IV) of the biodegradable polyester resin composition according to the examples may be about 0.9 dL / g or more. The intrinsic viscosity of the biodegradable polyester resin composition according to the examples may be about 0.95 dL / g or more, about 1.0 dL / g or more, about 1.1 dL / g or more, about 1.2 dL / g or more, or about 1.3 dL / g or more. The intrinsic viscosity of the biodegradable polyester resin composition according to the examples may be about 0.95 dL / g to about 1.7 dL / g. The intrinsic viscosity of the biodegradable polyester resin composition according to the examples may be about 1.3 dL / g to about 1.7 dL / g. The intrinsic viscosity of the biodegradable polyester resin composition according to the examples may be about 1.4 dL / g to about 1.7 dL / g.

[0276] The process for preparing the biodegradable polyester resin composition according to the embodiment is as follows.

[0277] Referring to FIG. 1, the biodegradable polyester resin manufacturing apparatus includes a slurry agitator 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.

[0278] The method for producing the biodegradable polyester resin includes preparing a slurry containing the diol and the aromatic dicarboxylic acid.

[0279] The step of preparing the slurry may include a step of mixing and treating the diol and the aromatic dicarboxylic acid. That is, the step of preparing the slurry may be a pretreatment step prior to the esterification reaction, in which the diol and the aromatic dicarboxylic acid are mixed and slurried. In this case, the diol may include a biomass-based diol component.

[0280] The temperature of the slurry of the diol and the aromatic dicarboxylic acid may be higher than the melting point of the diol by about 5° C. to about 15° C. For example, when the diol is 1,4-butanediol, the temperature of the slurry may be about 35° C. to about 45° C.

[0281] The diol and the aromatic dicarboxylic acid are added to the slurry mixer 100 and stirred to prepare the slurry.

[0282] By mixing the diol and the aromatic dicarboxylic acid, pretreating them, and forming a slurry, it is possible to not only react the diol and the aromatic dicarboxylic acid uniformly, but also to effectively accelerate the esterification reaction, thereby improving the reaction efficiency.

[0283] In particular, when the aromatic dicarboxylic acid is completely crystalline and in the form of a powder, such as terephthalic acid, its solubility in the diol is very low, making it difficult to achieve a homogeneous reaction. Therefore, the pretreatment process of forming a slurry can play a very important role in improving the reaction efficiency and providing biodegradable polyester resins, sheets, films, and molded articles having excellent physical properties according to embodiments of the present invention.

[0284] When the aromatic dicarboxylic acid is terephthalic acid, the terephthalic acid has complete crystallinity, no melting point, and is a white crystal that sublimes at approximately 300°C under atmospheric pressure. Since the solubility of the terephthalic acid in the diol is very low, a homogeneous reaction is difficult to occur. Therefore, when a pretreatment process is performed before the esterification reaction, the surface area of the terephthalic acid is increased to react with the diol within the solid matrix of the terephthalic acid, thereby inducing a homogeneous reaction.

[0285] Furthermore, when the aromatic dicarboxylic acid is dimethyl terephthalate, the pretreatment process can prepare the dimethyl terephthalate in a molten state at about 142°C to 170°C and allow it to react with the diol, thereby making the esterification reaction faster and more efficient.

[0286] Meanwhile, in the pretreatment step of preparing 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.

[0287] For example, the aromatic dicarboxylic acid may include terephthalic acid, and the terephthalic acid may have an average particle size (D50) of 10 μm to 400 μm, as measured by a particle size analyzer Microtrac S3500 in particle size distribution (PSD), and the standard deviation for the average particle size (D50) may be 100 or less. The standard deviation refers to the square root of the variance. 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 diols and the reaction rate.

[0288] In the pretreatment step, the diol and the aromatic dicarboxylic acid can be mixed and charged into a slurry mixer 100 (tank).

[0289] The slurry agitator 100 may be more advantageous in achieving efficient agitation, for example, if the lowest part is anchor-type, the height to the agitator is 20 mm or more, and three or more rotor blades are provided.

[0290] For example, the height of the slurry agitator 100 may be 20 mm or more, i.e., the space between the reactor and the bottom of the agitator may be almost equal to the reactor height, in which case a slurry can be obtained without precipitation. If the shape, form, and rotor of the agitator do not satisfy the above conditions, the aromatic dicarboxylic acid may settle to the bottom when the diol and aromatic dicarboxylic acid are initially mixed, and in this case, phase separation may occur.

[0291] The pretreatment step of producing the slurry may include a step of mixing the diol and the aromatic dicarboxylic acid and stirring the mixture at about 30°C to about 100°C, at about 50 rpm to about 200 rpm, for 10 minutes or more, for example, 10 minutes to 200 minutes.

[0292] The diol may have the same characteristics as described above.

[0293] The diol may be added at once or in portions, for example, the diol may be added separately when mixed with the aromatic dicarboxylic acid and when mixed with the aliphatic dicarboxylic acid.

[0294] The aromatic dicarboxylic acid may have the same characteristics as described above.

[0295] In the pretreatment step of producing the slurry, the molar ratio of the diol to the aromatic dicarboxylic acid may be about 0.8:1 to about 2:1. In the pretreatment step of producing the slurry, the molar ratio of the diol to the aromatic dicarboxylic acid may be about 1.1:1 to about 1.5:1. In the pretreatment step of producing the slurry, the molar ratio of the diol to the aromatic dicarboxylic acid may be about 1.2:1 to about 1.5:1.

[0296] When the diol is added in an amount greater than that of the aromatic dicarboxylic acid, the aromatic dicarboxylic acid can be easily dispersed.

[0297] In addition, an additive may be added to the slurry. The nanocellulose and / or the metal salt may be added to the slurry in the form of a dispersion or a solution.

[0298] The method for producing the biodegradable polyester resin involves mixing a diol and an aromatic dicarboxylic acid, pretreating the resulting slurry, esterifying the resulting slurry to obtain a prepolymer, and then subjecting the prepolymer to a condensation polymerization reaction, thereby efficiently achieving the desired structure and properties of the biodegradable polyester resin according to the present invention.

[0299] The method for preparing the biodegradable polyester resin includes esterifying the slurry and the aliphatic dicarboxylic acid to prepare a prepolymer. The slurry and the aliphatic dicarboxylic acid may be reacted in the ester reaction section.

[0300] The use of the slurry in the esterification reaction can shorten the reaction time, for example, the slurry obtained in the pretreatment step can shorten the reaction time of the esterification reaction by 1.5 times or more.

[0301] The esterification reaction can be carried out at least twice, and a prepolymer can be formed by the esterification reaction, which is then fed to the polycondensation step.

[0302] In one embodiment, the esterification reaction can be carried out simultaneously after adding an aliphatic dicarboxylic acid, or a diol and an aliphatic dicarboxylic acid, to the slurry. That is, the slurry can be introduced into the esterification reactor, and then the aliphatic dicarboxylic acid alone, or the aliphatic dicarboxylic acid and the diol can be introduced into the esterification reactor, and the esterification reaction can be carried out.

[0303] The diol and the aliphatic dicarboxylic acid may be added in the form of a slurry to a slurry containing the aromatic dicarboxylic acid.

[0304] The aliphatic dicarboxylic acid in the slurry of the diol and the aliphatic dicarboxylic acid may have an average particle size (D50) of about 50 μm to about 150 μm.The aliphatic dicarboxylic acid in the slurry of the diol and the aliphatic dicarboxylic acid may have an average particle size (D50) of about 60 μm to about 120 μm.

[0305] The total number of moles of the diols added in the esterification reaction may be about 1.0 to about 1.8 relative to the total number of moles of the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid. The total number of moles of the diols added in the esterification reaction may be about 1.1 to about 1.6 relative to the total number of moles of the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid.

[0306] 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.

[0307] In addition, various additives such as the nanocellulose may also be added to the slurry of the diol and the aliphatic dicarboxylic acid.

[0308] The esterification reaction can be carried out at about 250°C or lower for about 0.5 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 atmospheric pressure or reduced pressure until the by-product water is reduced to 95% theoretically. For example, the esterification reaction can be carried out for 0.5 to 5.5 hours, 0.5 to 4.5 hours, or 1 to 4 hours, but is not limited thereto.

[0309] In one embodiment, the slurry, the aliphatic dicarboxylic acid, and the diol may be mixed to carry out a first esterification reaction, and the molar ratio of the aromatic dicarboxylic acid to the aliphatic dicarboxylic acid in the reaction mixture for the first esterification reaction may be 1:0.05 to 1:0.5.

[0310] After the first esterification reaction, a mixture of the slurry, the aliphatic dicarboxylic acid, and the diol may be introduced into the esterification reaction section to carry out a second esterification reaction together with the first esterification reaction product. In this case, the molar ratio of the aromatic dicarboxylic acid to the aliphatic dicarboxylic acid in the mixture introduced in the second esterification reaction may be 0.05:1 to 0.5:1.

[0311] The first esterification reaction can be carried out at 250°C or lower for 1.25 to 4 hours. Specifically, the first esterification reaction can be carried out at 180 to 250°C, 185 to 240°C, or 200 to 240°C under atmospheric pressure or reduced pressure until the by-product water reaches theoretically 95%. For example, the first esterification reaction can be carried out for 1.25 to 4 hours, 1.25 to 3.5 hours, or 1.5 to 3 hours, but is not limited thereto.

[0312] The second esterification reaction can be carried out at about 250°C or below for 0.25 to 3.5 hours. Specifically, the second esterification reaction can be carried out at 180 to 250°C, 185 to 240°C, or 200 to 240°C under atmospheric pressure or reduced pressure until the by-product water reaches theoretically 95%. For example, the second esterification reaction can be carried out for 0.5 to 3 hours, 1 to 2.5 hours, or 1.5 to 2.5 hours, but is not limited thereto.

[0313] In the first esterification reaction and the second esterification reaction, the reaction temperature, reaction time, and the amounts of the diol, aromatic dicarboxylic acid, and aliphatic dicarboxylic acid added can be adjusted, respectively, to adjust the ratio of the number of the first block to the second block, the alternation rate, the hard segment rate, and the soft segment rate. Furthermore, when the esterification reaction is carried out separately into the first esterification reaction and the second esterification reaction, the overall esterification reaction can be precisely controlled. Therefore, when the esterification reaction is carried out separately, the reaction stability and reaction uniformity of the esterification reaction can be improved.

[0314] In addition, the branching agent can be added to the second esterification reaction. That is, the slurry, the aliphatic dicarboxylic acid, the diol mixture, the branching agent, and the first esterification reaction product can react to form the prepolymer. The characteristics and content of the branching agent can be the same as those described above.

[0315] After the second esterification reaction is completed, a third esterification reaction can be carried out by adding a monomer composition containing at least one of the diol, the aromatic dicarboxylic acid, and the aliphatic dicarboxylic acid to the second esterification reaction product.

[0316] 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.

[0317] In addition, in the monomer composition, the molar ratio of the aromatic dicarboxylic acid to the aliphatic dicarboxylic acid may be about 1:1 to about 1:3. In the monomer composition, the molar ratio of the aromatic dicarboxylic acid to the aliphatic dicarboxylic acid may be about 1:1.3 to about 1:3.

[0318] In addition, in the monomer composition, the molar ratio of the diol to the total dicarboxylic acid may be about 0.8:1 to 1:1.2.

[0319] The third esterification reaction can be carried out at about 250° C. or lower for 0.1 to 0.5 hours. Specifically, the third esterification reaction can be carried out at 180 to 250° C., 185 to 240° C., or 200 to 240° C., under normal pressure or reduced pressure. For example, the third esterification reaction can be carried out for 5 to 60 minutes, 10 to 50 minutes, or 10 to 40 minutes, but is not limited thereto.

[0320] The third esterification reaction can form a prepolymer.

[0321] When the third esterification reaction is carried out using the monomer composition as described above under the process conditions as described above, the alternation ratio, the hard segment ratio, and the soft segment ratio can be appropriately adjusted.

[0322] The third esterification reaction does not necessarily require the second esterification reaction product. That is, the third esterification reaction can be carried out using the monomer composition and other additives such as a catalyst. The second esterification reaction product and the third esterification reaction product can then be mixed together to produce the prepolymer. In this case, the third esterification reaction product can be mixed with the second esterification reaction product in an amount of about 0.1 to about 5 parts by weight, based on 100 parts by weight of the second esterification reaction product, to produce the prepolymer.

[0323] The water-average molecular weight of the prepolymer may be about 500 to about 10,000 g / mol. For example, the water-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. When the water-average molecular weight of the prepolymer satisfies the above range, the molecular weight of the polymer in the condensation polymerization reaction can be efficiently increased.

[0324] The water-average molecular weight can be measured using gel permeation chromatography (GPC). Specifically, data calculated by gel permeation chromatography includes various items such as Mn, Mw, and Mp, and the molecular weight can be measured based on the water-average molecular weight (Mn).

[0325] 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 unit 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. Alternatively, the reinforcing material and / or the metal salt may be introduced together with the aliphatic dicarboxylic acid. Alternatively, the reinforcing material and / or the metal salt may be introduced into the esterification reaction unit 200 after the first esterification reaction and before the second esterification reaction.

[0326] Since the reinforcing material and / or the metal salt are added to the esterification reaction, the reinforcing material and / or the metal salt may be uniformly dispersed in the biodegradable polyester resin.

[0327] The reinforcing material may have the characteristics described above, in particular the nanocellulose may be used as the reinforcing material.

[0328] The nanocellulose may be pretreated with a bead mill, ultrasonically, or by high-speed dispersion at about 1000 rpm to about 1500 rpm before being added. Specifically, the nanocellulose may be water-dispersed nanocellulose that has been pretreated with a bead mill or ultrasonically.

[0329] First, the bead mill pretreatment can be performed using a vertical mill or a horizontal mill as a wet milling device. The horizontal mill is preferred because it can fill a larger amount of beads into the chamber, reduces uneven wear on the machine, reduces wear on the beads, and is easy to maintain, but is not limited thereto.

[0330] The bead mill pretreatment can be carried out using one or more types of beads selected from the group consisting of zirconium, zircon, zirconia, quartz, and aluminum oxide.

[0331] Specifically, the bead mill pretreatment can be performed using beads having a diameter of about 0.3 mm to about 1 mm. For example, the diameter of the beads may be about 0.3 mm to about 0.9 mm, about 0.4 mm to about 0.8 mm, about 0.45 mm to about 0.7 mm, or about 0.45 mm to about 0.6 mm.

[0332] The dispersibility of nanocellulose can be further improved by ensuring that the bead diameter is within the above range. If the bead diameter exceeds the above range, the average particle size and particle size deviation of the nanocellulose may increase, resulting in poor dispersibility.

[0333] In addition, the bead mill pretreatment preferably uses beads with a higher specific gravity than nanocellulose, as this allows for sufficient energy transfer. For example, the beads may be one or more selected from the group consisting of zirconium, zircon, zirconia, quartz, and aluminum oxide, which have a higher specific gravity than the water-dispersed nanocellulose. Zirconium beads, which have a specific gravity four times or more higher than that of the water-dispersed nanocellulose, are preferred, but are not limited thereto.

[0334] The ultrasonic pretreatment is a method of physically closing or pulverizing nanoparticles by emitting 20 kHz ultrasonic waves into a solution.

[0335] The ultrasonic pretreatment can be performed at an output of 30,000 J / s or less for less than 30 minutes. For example, the ultrasonic pretreatment can be performed at an output of 25,000 J / s or less or 22,000 J / s or less for 25 minutes or less, 20 minutes or less, or 18 minutes or less. By keeping the output and duration within the above ranges, the effect of the ultrasonic pretreatment, i.e., improvement in dispersibility, can be maximized. If the output exceeds the above range, the nanoparticles may re-agglomerate, resulting in poor dispersibility.

[0336] According to embodiments, the nanocellulose may be pretreated by bead milling or ultrasonic pretreatment. Alternatively, the nanocellulose according to embodiments may be pretreated by both bead milling and ultrasonic pretreatment. In this case, it is preferable to perform ultrasonic pretreatment after bead milling pretreatment in order to prevent re-agglomeration and improve dispersibility.

[0337] According to embodiments, the nanocellulose may be pretreated by bead milling or ultrasonic pretreatment. Alternatively, the nanocellulose according to embodiments may be pretreated by both bead milling and ultrasonic pretreatment. In this case, it is preferable to perform ultrasonic pretreatment after bead milling pretreatment in order to prevent re-agglomeration and improve dispersibility.

[0338] The nanocellulose contains ionically bonded metals, making it highly dispersible in water. Furthermore, the bead mill pretreatment and / or ultrasonic pretreatment can provide an aqueous dispersion of nanocellulose with a very high degree of dispersibility. The nanocellulose content in the aqueous nanocellulose dispersion can be about 1 wt% to about 50 wt%.

[0339] The esterification reaction can be carried out using a titanium-based catalyst and / or a germanium-based catalyst, specifically, by adding the titanium-based catalyst and / or the germanium-based catalyst to the slurry.

[0340] Alternatively, the titanium-based catalyst and / or the germanium-based catalyst may be added to the slurry before the first esterification reaction, and the titanium-based catalyst and / or the germanium-based catalyst may be further added to the product of the first esterification reaction.

[0341] 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.

[0342] The catalyst content 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, the titanium-based catalyst or germanium-based catalyst may be 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. When the catalyst content satisfies the above range, physical properties can be further improved.

[0343] The thermal stabilizer may be introduced together with the slurry before the esterification reaction. The thermal stabilizer may be introduced into the esterification reaction unit 200 during the esterification reaction. The thermal stabilizer may be introduced into the ester reaction product after the esterification reaction. The thermal stabilizer may be introduced together with the aliphatic dicarboxylic acid. The thermal stabilizer may be introduced into the esterification reaction unit 200 after the first esterification reaction and before the second esterification reaction.

[0344] The characteristics of the heat stabilizer may be the same as those described above.

[0345] 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. When the content of the heat stabilizer satisfies the above range, degradation of the polymer due to high temperatures during the reaction process can be controlled and the number of polymer end groups can be reduced, thereby improving color.

[0346] After the esterification reaction is complete, one or more additives selected from the group consisting of silica, potassium, or magnesium, and color correction agents such as cobalt acetate may be further added to the esterification reaction product. That is, after the esterification reaction is complete, the additives and / or color correction agents may be added and stabilized before the condensation polymerization reaction is carried out. The additives and / or color correction agents may be added after the esterification reaction is complete and then added to the condensation polymerization reaction section 300 together with the prepolymer. As a result, the additives and / or color correction agents may be uniformly dispersed in the biodegradable polyester resin.

[0347] Alternatively, the inorganic filler may be added to the esterification reaction product after the esterification reaction is completed. That is, after the esterification reaction is completed, the inorganic filler may be added and stabilized before the condensation polymerization reaction is performed. The characteristics of the inorganic filler are as described above. The inorganic filler may be added to the condensation polymerization reaction unit 300 together with the prepolymer to perform the condensation polymerization process. This allows the inorganic filler to be uniformly dispersed in the biodegradable polyester resin.

[0348] 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 may recover by-products generated in the esterification reaction by applying a vacuum pressure to the esterification reaction unit 200 or by refluxing the esterification reaction by-products.

[0349] The method for preparing the biodegradable polyester resin includes a step of subjecting the prepolymer to a polycondensation reaction. The polycondensation reaction can be carried out as follows.

[0350] The prepolymer is introduced into the polycondensation reaction section 300. In addition, at least one of the reinforcing material, the heat stabilizer, the color correction agent, the inorganic filler, the metal salt, and other additives may be introduced into the polycondensation reaction section 300 together with the prepolymer.

[0351] The polycondensation reaction can then 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, 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.

[0352] The polycondensation reaction may include a first polycondensation reaction and a second polycondensation reaction.

[0353] For example, the primary condensation polymerization can be carried out at about 260°C or lower, about 250°C or lower, 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, for about 0.5 hours to about 3.5 hours, about 0.5 hours to about 3.0 hours, or about 0.5 hours to about 2.8 hours.

[0354] The secondary condensation polymerization 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.

[0355] In addition, a titanium-based catalyst or a germanium-based catalyst may be further added to the prepolymer before the polycondensation reaction.In addition, in addition, in the prepolymer before the polycondensation reaction, one or more selected from the group consisting of additives such as silica, potassium, or magnesium; amine-based stabilizers such as trimethyl phosphate, triphenyl phosphate, trimethylphosphine, phosphoric acid, phosphorous acid, or tetraethylenepentamine; and polymerization catalysts such as antimony trioxide, antimony trioxide, or tetrabutyl titanate may be further added.

[0356] The water-average molecular weight of the polymer may be about 30,000 g / mol or more. For example, the water-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. When the water-average molecular weight of the polymer satisfies the above range, the physical properties, impact resistance, durability, and moldability can be further improved.

[0357] In addition, the second collecting unit 520 collects reaction by-products such as water from the polycondensation reaction unit 300. The second collecting unit 520 may apply a vacuum pressure to the polycondensation reaction unit 300 to collect by-products generated in the polycondensation reaction.

[0358] The second recovery unit 520 may apply a vacuum pressure of about 0.1 torr to about 1 torr to the inside of the polycondensation reaction unit 300. The second recovery unit 520 may apply a vacuum pressure of about 0.1 torr to about 0.9 torr to the inside of the polycondensation reaction unit 300.

[0359] The hydrolysis stabilizer and / or chain extender are then added to the polymer. The polymer, hydrolysis stabilizer, and chain extender are then uniformly mixed and maintained at a temperature of about 200°C to about 260°C for about 1 minute to about 15 minutes. This allows the polymer to react with the hydrolysis stabilizer and / or chain extender.

[0360] Alternatively, the hydrolysis stabilizer and / or the chain extender may be added to the polycondensation reactor 300 using a static mixer and reacted with the polymer. The reaction temperature of the hydrolysis stabilizer and / or the chain extender in the polycondensation reactor 300 may be about 200°C to about 260°C. The reaction time of the hydrolysis stabilizer and / or the chain extender in the polycondensation reactor 300 may be about 1 minute to about 15 minutes.

[0361] The hydrolysis stabilizer may have the same characteristics as those described above.

[0362] The chain extender may have the same characteristics as those described above.

[0363] As a result, the biodegradable polyester resin composition according to the embodiment may have an appropriate degree of hydrolysis and a high degree of biodegradability.

[0364] Pellets can then be made from the polymer.

[0365] Specifically, the polymer can be cooled to about 15°C or below, about 10°C or below, or about 6°C or below, and then cut into pellets. Alternatively, the polymer can be cut at a temperature of about 40°C to about 60°C.

[0366] The cutting step can be performed using any pellet cutting machine known in the art, and the pellets may have various shapes. The pellet cutting method may include an underwater cutting method or a strand cutting method.

[0367] The pellets may be subjected to further post-treatment processes. The pellets may be fed into the post-treatment section 400 to undergo the post-treatment processes.

[0368] The post-treatment process can be performed in the post-treatment unit 400. The pellets are introduced into the post-treatment unit 400. The post-treatment unit 400 then melts the introduced pellets by frictional heat and re-extrudes them. That is, the post-treatment unit 400 may include a press such as a biaxial press.

[0369] The post-treatment temperature may be about 230°C to about 270°C. The post-treatment temperature may be about 230°C to about 260°C. The post-treatment temperature may be about 240°C to about 265°C. The post-treatment temperature may be about 240°C to about 260°C.

[0370] The post-treatment process time may be about 30 seconds to about 3 minutes, about 50 seconds to about 2 minutes, or about 1 minute to about 2 minutes.

[0371] The resin extruded from the press may then be cooled, cut, and processed into post-processed pellets, i.e., the resin extruded from the press may be reprocessed into pellets through the cutting step described above.

[0372] The crystallinity of the pellets may be improved by the post-treatment process. The content of residual substances contained in the pellets may be adjusted by the post-treatment process. In particular, the content of oligomers contained in the pellets may be adjusted by the post-treatment process. The content of residual solvents contained in the pellets may be adjusted by the post-treatment process.

[0373] Thus, the post-treatment process can appropriately adjust the mechanical properties, biodegradability, UV resistance, optical properties, or hydrolysis resistance of the biodegradable polyester resin.

[0374] After the pellets are produced, the biodegradable polyester resin can be compounded with the two biodegradable polyester resins, and at least one of the inorganic filler, the light stabilizer, the color correction agent, and the other additives can be compounded with the biodegradable polyester resin and the two biodegradable polyester resins.

[0375] The compounding process is as follows.

[0376] The biodegradable polyester resin and the two biodegradable polyester resins are mixed with at least one of the inorganic filler, the heat stabilizer, the color corrector, the metal salt, and the other additives, and then charged into a press. The mixed biodegradable polyester resin composition is melted in the press at a temperature of about 120°C to about 260°C and mixed with each other. The melt-mixed biodegradable polyester resin composition is then extruded, cooled, cut, and re-pelletized. Through this process, the two biodegradable polyester resins are combined to produce a biodegradable polyester resin composition according to the embodiment.

[0377] Alternatively, the inorganic filler, the heat stabilizer, the color correction agent, the metal salt, and the other additives may be added during the process of polymerizing the biodegradable polyester resin.

[0378] A biodegradable polyester film can be produced using the biodegradable polyester resin composition according to the embodiment.

[0379] 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.

[0380] The biodegradable polyester film according to the embodiment may have substantially the same degree of hydrolysis and biodegradability as the biodegradable polyester resin composition described above.

[0381] Meanwhile, the biodegradable polyester film can be produced using the biodegradable polyester resin or biodegradable polyester resin pellets.

[0382] Specifically, the method for producing the biodegradable polyester film may include the steps of preparing a biodegradable polyester resin composition according to the embodiment, and drying and melt-extruding the biodegradable polyester resin composition.

[0383] 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 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 to about 12 hours, or about 4 to about 10 hours. By ensuring that the pellet drying process conditions satisfy the above ranges, the quality of the produced biodegradable polyester film or molded product can be further improved. The moisture content of the biodegradable polyester resin composition after the drying step may be about 500 ppm or less based on the total weight of the biodegradable polyester resin composition.

[0384] In the drying and melt-extrusion steps, the melt-extrusion can be performed at a temperature of about 250°C or less. For example, the melt-extrusion can be performed at a temperature of about 245°C or less, about 220°C or less, about 215°C or less, about 100°C to about 250°C, about 120°C to about 245°C, or about 130°C to about 215°C. The melt-extrusion can be performed in a blown film process. The melt-extrusion can be performed using a T-die.

[0385] The film manufacturing process may also be a calendering process.

[0386] The biodegradable polyester resin can be used to produce a biodegradable polyester molded article.

[0387] Specifically, the molded article can be manufactured by molding the biodegradable polyester resin composition using a method known in the art, such as extrusion or injection molding. The molded article may be, but is not limited to, an injection molded article, an extrusion molded article, a thin film molded article, a blow molding or blow molded article, a 3D filament, a building interior material, or the like.

[0388] For example, the molded article may be in the form of a film or sheet used for agricultural mulching film, disposable gloves, disposable film, disposable envelopes, food packaging material, or volume-based garbage bags, or may be in the form of a fiber used for woven fabrics, knitted fabrics, nonwoven fabrics, ropes, etc. As shown in Fig. 2, the molded article may also be in the form of a disposable container used for food packaging such as lunch boxes. The molded article may also be in various shapes such as disposable straws, spoons and chopsticks, eating plates, and forks.

[0389] In particular, the molded article can be formed from the biodegradable polyester resin, which can improve not only physical properties such as impact absorption energy and hardness, but also impact resistance and durability, and therefore can exhibit excellent properties when applied to packaging materials for products stored and transported at low temperatures, automotive interior materials requiring durability, garbage bags, mulching films, and disposable products.

[0390] The physical properties of the biodegradable film and the biodegradable molded article can be measured in a similar manner to that of the biodegradable polyester resin composition according to the examples.

[0391] The biodegradability of the biodegradable polyester resin composition according to the examples can be measured by the following method.

[0392] To measure the biodegradability, the biodegradable polyester resin composition according to the example was mixed with compost and subjected to an accelerated biodegradation test 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 example was measured using gel permeation chromatography (GPC). The biodegradability was calculated by dividing the difference between the initial number average molecular weight and the number average molecular weight after biodegradation for a certain period of time by the initial number average molecular weight.

[0393] The biodegradability may be expressed by the following mathematical formula 10.

[0394] [Formula 10] JPEG2025525702000024.jpg13149

[0395] Here, the biodegradable polyester resin composition according to the embodiment is mixed with compost and subjected to an accelerated biodegradation test for a certain period of time at a temperature of 60°C and a humidity of 90%. The initial number average molecular weight of the biodegradable polyester resin composition before the accelerated biodegradation test and the number average molecular weight of the biodegradable polyester resin composition after the accelerated biodegradation test for a certain period of time are measured by gel permeation chromatography (GPC).

[0396] The degree of biodegradation was calculated by dividing the difference between the initial number average molecular weight and the number average molecular weight after biodegradation for a certain period of time by the initial number average molecular weight.

[0397] The compost may also include about 40 wt% swine manure, about 15 wt% chicken manure, about 37 wt% sawdust, about 5 wt% zeolite, and about 3 wt% microbial preparation.

[0398] The manufacturer of the compost may be TaeheungF&G, and the product name of the compost may be Jisei-do (by-product fertilizer grade 1 compost).

[0399] In addition, when measuring the biodegradability, the biodegradable polyester resin composition according to the embodiment is prepared into a sheet having a thickness of about 300 μm. The prepared sheet is then cut into flakes having a size of about 30 mm x 30 mm. The flakes can be mixed with the compost to carry out the accelerated biodegradation test.

[0400] In the biodegradable polyester resin composition according to the examples, the biodegradability after one week may be about 40% to about 70%. In the biodegradable polyester resin composition according to the examples, the biodegradability after one week may be about 45% to about 65%. In the biodegradable polyester resin composition according to the examples, the biodegradability after one week may be about 47% to about 63%. In the biodegradable polyester resin composition according to the examples, the biodegradability after one week may be about 49% to about 62%.

[0401] In the biodegradable polyester resin composition according to the embodiment, the biodegradability after two weeks may be about 50% to about 70%. In the biodegradable polyester resin composition according to the embodiment, the biodegradability after two weeks may be about 55% to about 68%.

[0402] In the biodegradable polyester resin composition according to the embodiment, the biodegradability after 3 weeks may be about 63% to about 75%.In the biodegradable polyester resin composition according to the embodiment, the biodegradability after 3 weeks may be about 63% to about 73%.

[0403] In the biodegradable polyester resin composition according to the embodiment, the biodegradability after 4 weeks may be about 73% to about 85%. In the biodegradable polyester resin composition according to the embodiment, the biodegradability after 4 weeks may be 75% to 82%.

[0404] In the biodegradable polyester resin composition according to the embodiment, the biodegradability after 6 weeks may be about 80% to about 90%. In the biodegradable polyester resin composition according to the embodiment, the biodegradability after 6 weeks may be about 82% to about 88%.

[0405] In the biodegradable polyester resin composition according to the embodiment, the biodegradability after 9 weeks may be about 85% or more. In the biodegradable polyester resin composition according to the embodiment, the biodegradability after 9 weeks may be about 87% or more. In the biodegradable polyester resin composition according to the embodiment, the biodegradability after 9 weeks may be about 88% or more. In the biodegradable polyester resin composition according to the embodiment, the biodegradability after 9 weeks may be about 89% or more. In the biodegradable polyester resin composition according to the embodiment, the biodegradability after 9 weeks may be about 90% or more.

[0406] The biodegradable polyester resin composition according to the embodiment has the above-mentioned biodegradability and biodegradability increase rate, and therefore may have appropriate durability in practical living areas and have high biodegradability when disposed of after use.

[0407] The degree of hydrolysis of the biodegradable polyester resin composition according to the examples can be measured by the following method.

[0408] To measure the degree of hydrolysis, the biodegradable polyester resin composition according to the example was immersed in water (100% RH) at 80°C and then subjected to an accelerated hydrolysis test. After a certain period of time, the number average molecular weight of the biodegradable polyester resin composition according to the example was measured using gel permeation chromatography (GPC). The degree of hydrolysis was calculated by dividing the difference between the initial number average molecular weight and the number average molecular weight after hydrolysis for a certain period of time by the initial number average molecular weight.

[0409] The degree of hydrolysis may be expressed by the following mathematical formula 12:

[0410] [Formula 11] JPEG2025525702000025.jpg12146

[0411] Here, the biodegradable polyester resin composition according to the embodiment is immersed in water at 80°C and then subjected to an accelerated hydrolysis test for a certain period of time. The initial number average molecular weight of the biodegradable polyester resin composition before the accelerated hydrolysis test and the number average molecular weight after hydrolysis of the biodegradable polyester resin composition that has been subjected to the accelerated hydrolysis test for a certain period of time are measured by gel permeation chromatography (GPC).

[0412] The degree of hydrolysis was calculated by dividing the difference between the initial number average molecular weight and the number average molecular weight after hydrolysis for a certain period of time by the initial number average molecular weight.

[0413] When measuring the degree of hydrolysis, the biodegradable polyester resin composition according to the embodiment is prepared into a sheet having a thickness of about 300 μm. The prepared sheet is then cut into flakes having a size of about 30 mm x 30 mm. The flakes can be immersed in warm water to perform the accelerated hydrolysis test.

[0414] In the biodegradable polyester resin composition according to the embodiment, the degree of hydrolysis after one week may be about 40% to about 65%. In the biodegradable polyester resin composition according to the embodiment, the degree of hydrolysis after one week may be about 45% to about 63%.

[0415] In the biodegradable polyester resin composition according to the embodiment, the degree of hydrolysis after 2 weeks may be about 80% to about 93%. In the biodegradable polyester resin composition according to the embodiment, the degree of hydrolysis after 2 weeks may be about 85% to about 92%.

[0416] In the biodegradable polyester resin composition according to the embodiment, the degree of hydrolysis after 3 weeks may be about 90% to about 97%.In the biodegradable polyester resin composition according to the embodiment, the degree of hydrolysis after 3 weeks may be about 91% to about 96%.

[0417] In the biodegradable polyester resin composition according to the embodiment, the degree of hydrolysis after 4 weeks may be about 92% to about 99%.In the biodegradable polyester resin composition according to the embodiment, the degree of hydrolysis after 4 weeks may be about 93% to about 97%.

[0418] In the biodegradable polyester resin composition according to the embodiment, the degree of hydrolysis after 6 weeks may be about 94% or more.In the biodegradable polyester resin composition according to the embodiment, the degree of hydrolysis after 6 weeks may be about 95% or more.

[0419] In the biodegradable polyester resin composition according to the embodiment, the degree of hydrolysis after 9 weeks may be about 95% or more.In the biodegradable polyester resin composition according to the embodiment, the degree of hydrolysis after 9 weeks may be about 96% or more.

[0420] Because the biodegradable polyester resin compositions according to the examples have a degree of hydrolysis and a rate of increase in the degree of hydrolysis within the above-mentioned ranges, the biodegradable polyester resin compositions according to the examples may have appropriate durability in everyday life and may be easily hydrolyzed when discarded. That is, because the biodegradable polyester resin compositions according to the examples have a degree of hydrolysis and a rate of increase in the degree of hydrolysis within an appropriate range, they may have sufficient hydrolysis resistance when used for an appropriate period of time in disposable packaging, etc. Furthermore, the biodegradable polyester resin compositions according to the examples may be easily decomposed by hydrolysis and biodegradation over a sufficient period of time not only when discarded in soil but also when discarded in rivers, oceans, etc.

[0421] In the biodegradable polyester resin composition according to the embodiment, the biodegradability per aliphatic carboxylic acid may be about 1.7 or more. The biodegradability per aliphatic carboxylic acid may also be about 1.75 or more. The biodegradability per aliphatic carboxylic acid may also be about 1.79 or more. The biodegradability per aliphatic carboxylic acid may also be about 1.8 or more. The biodegradability per aliphatic carboxylic acid may also be about 1.85 or more. The biodegradability per aliphatic carboxylic acid may also be about 1.90 or more. The maximum value of the biodegradability per aliphatic carboxylic acid may also be about 4.

[0422] The biodegradability per aliphatic carboxylic acid is a value obtained by dividing the biodegradability after 9 weeks by the proportion of the aliphatic carboxylic acid based on the total dicarboxylic acids. The biodegradability per aliphatic carboxylic acid is a value obtained by dividing the biodegradability after 9 weeks by the proportion of the aliphatic carboxylic acid in mole percent based on the total dicarboxylic acids.

[0423] The biodegradability per aliphatic carboxylic acid may be expressed by the following mathematical formula 12.

[0424] [Formula 12] JPEG2025525702000026.jpg12144

[0425] The biodegradable polyester resin composition according to the embodiment may have a crystallization temperature (Tc). When the biodegradable polyester resin composition according to the embodiment contains the polyester resin as a main component, the crystallization temperature of the biodegradable polyester resin composition according to the embodiment may be substantially the same as the crystallization temperature of the polyester resin.

[0426] The crystallization temperature of the biodegradable polyester resin composition according to the examples may be about 38°C to about 58°C. The crystallization temperature of the biodegradable polyester resin composition according to the examples may be about 40°C to about 57°C. The crystallization temperature of the biodegradable polyester resin composition according to the examples may be about 43°C to about 56°C. The crystallization temperature of the biodegradable polyester resin composition according to the examples may be about 45°C to about 58°C.

[0427] The biodegradable polyester resin composition according to the embodiment may have a glass transition temperature (Tg). When the biodegradable polyester resin composition according to the embodiment contains the polyester resin as a main component, the glass transition temperature of the biodegradable polyester resin composition according to the embodiment may be substantially the same as the glass transition temperature of the polyester resin.

[0428] The glass transition temperature of the biodegradable polyester resin composition according to the examples may be about -50°C to about -15°C. The glass transition temperature of the biodegradable polyester resin composition according to the examples may be about -37°C to about -15°C. The glass transition temperature of the biodegradable polyester resin composition according to the examples may be about -30°C to about -20°C. The glass transition temperature of the biodegradable polyester resin composition according to the examples may be about -30°C to about -21°C.

[0429] The biodegradable polyester resin composition according to the embodiment may have a melting point (Tm). When the biodegradable polyester resin composition according to the embodiment contains the polyester resin as a main component, the melting point of the biodegradable polyester resin composition according to the embodiment may be substantially the same as the melting point of the polyester resin.

[0430] The melting point of the biodegradable polyester resin composition according to the examples may be about 70°C to about 130°C. The melting point of the biodegradable polyester resin composition according to the examples may be about 99°C to about 122°C. The melting point of the biodegradable polyester resin composition according to the examples may be about 105°C to about 122°C. The melting point of the biodegradable polyester resin composition according to the examples may be about 110°C to about 122°C. The melting point of the biodegradable polyester resin composition according to the examples may be about 110°C to about 130°C.

[0431] Here, in order to measure the crystallization temperature, glass transition temperature, and melting point of the biodegradable polyester resin composition, film, and molded article according to the examples, a sample having a weight of about 5 mg to about 10 mg is obtained from the biodegradable polyester resin composition, film, and molded article according to the examples.

[0432] The sample is placed in a differential scanning calorimeter (e.g., Q2000, TA Instruments) and stabilized at about 25°C for about 1 minute. The sample is then cooled to about -70°C at a rate of about -5°C / min and heated to about 200°C at a rate of about 10°C / min. The sample is then maintained at about 200°C for about 1 minute and then cooled to about 25°C. The enthalpy change during the heating and cooling process of the sample can be measured. The minimum point of the endothermic peak may be the melting point (Tm). The point at which heat flow begins to change may be the glass transition temperature (Tg), and the maximum temperature of the exothermic peak may be the crystallization temperature (Tc).

[0433] The biodegradable polyester resin compositions, films, and molded articles according to the examples have crystallization temperatures, glass transition temperatures, and melting points within the above-mentioned ranges, and therefore may have appropriate mechanical properties, appropriate biodegradability, appropriate hydrolysis degree, appropriate thermal properties, and appropriate chemical resistance. In particular, the biodegradable polyester resin compositions, films, and molded articles according to the examples have crystallization temperatures, glass transition temperatures, and melting points within the above-mentioned ranges, and therefore may have appropriate flexibility.

[0434] Furthermore, the biodegradable polyester resin composition, film and molded article according to the examples may have a Young's modulus.

[0435] In the biodegradable polyester resin compositions, films, and molded articles according to Examples, the Young's modulus may be about 20 MPa to about 80 MPa. In the biodegradable polyester resin compositions, films, and molded articles according to Examples, the Young's modulus may be about 25 MPa to about 60 MPa. In the biodegradable polyester resin compositions, films, and molded articles according to Examples, the Young's modulus may be about 29 MPa to about 50 MPa. In the biodegradable polyester resin compositions, films, and molded articles according to Examples, the Young's modulus may be about 35 MPa to about 60 MPa.

[0436] In the biodegradable polyester resin composition, film, and molded article according to the examples, the initial elongation at break may be about 800% to about 1200%. In the biodegradable polyester resin composition, film, and molded article according to the examples, the initial elongation at break may be about 800% to about 1100%. In the biodegradable polyester resin composition, film, and molded article according to the examples, the initial elongation at break may be about 850% to about 1050%.

[0437] The biodegradable polyester resin composition according to the embodiment can be dried at a temperature of about 80°C for about 1 hour, placed in a stainless steel frame, and compressed at a temperature of about 210°C under a pressure of about 10 MPa for about 3 minutes to produce a biodegradable polyester sheet having a thickness of about 300 μm.

[0438] The Young's modulus and the elongation at break can be measured by the following method. Based on ASTM D638V type, the biodegradable polyester sheets, films and molded articles according to the examples were cut to prepare test pieces, and then tested at a tensile speed of 100 mm / min using an Instron universal testing machine (UTM, model 4206-001). The Young's modulus (kgf / mm) was measured using a program installed in the equipment. 2 =9.8 MPa) and elongation at break can be measured.

[0439] The composition of the biodegradable polyester resin, such as the number of the first blocks, the number of the second blocks, the alternation ratio, the ratio of the hard segments, the ratio of the soft segments, 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 agent, the metal salt, the hydrolysis stabilizer, the chain extender, the oligomer, or the heat stabilizer, may be appropriately adjusted so that the biodegradability per aliphatic carboxylic acid falls within the above range.

[0440] In particular, the biodegradable polyester resin composition according to the embodiment includes a polyester resin having an appropriate soft segment ratio, and the content of the diol bonded between the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid may be appropriate.

[0441] Therefore, the biodegradable polyester resin may appropriately contain the aliphatic dicarboxylic acid and a bond structure in which the aliphatic dicarboxylic acid is bonded to the diol, and therefore the biodegradable polyester resin may have appropriate crystal properties, and the biodegradable polyester resin composition according to the embodiment may have appropriate thermal and mechanical properties.

[0442] In particular, since the biodegradable polyester resin has a soft segment ratio within the above range, the biodegradable polyester resin composition according to the embodiment may have an appropriate Young's modulus, an appropriate glass transition temperature, an appropriate crystallization temperature, and an appropriate melting point.

[0443] In particular, the biodegradable polyester resin composition according to the embodiment may have appropriate flexibility due to the molecular structure described above, and may also be prevented from becoming sticky due to the molecular structure described above.

[0444] In addition, since the biodegradable polyester resin contains an appropriate amount of the structure in which the diol is bonded between the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid, the biodegradable polyester resin composition according to the embodiment may simultaneously have an appropriate degree of hydrolysis and an improved degree of biodegradation.

[0445] Therefore, the biodegradable polyester resin compositions according to the examples have appropriate flexibility during the period of actual use, and can be easily biodegraded after use.

[0446] In particular, the biodegradable polyester resin composition according to the embodiment can be effectively used for packaging films, etc. That is, films made from the biodegradable polyester resin composition according to the embodiment can be used for general purposes such as packaging. In this case, the biodegradable polyester resin composition according to the embodiment can maintain appropriate flexibility and chemical properties throughout the normal usage period of the user.

[0447] In addition, since the biodegradable polyester resin composition according to the embodiment has a high degree of biodegradability, the film manufactured using the biodegradable polyester resin composition according to the embodiment can be easily biodegraded when disposed of after use.

[0448] The above content will be explained in more detail with reference to the following examples, but the following examples are merely illustrative of the present invention and are not intended to limit the scope of the present invention.

[0449] <Production example> Production of pretreated cellulose nanocrystals Dry powder cellulose nanocrystals (NVC-100, manufactured by Celluforce) with particle sizes of approximately 1 μm to approximately 50 μm were dispersed in water at 1 wt % and then sonicated for 1 minute using a tip-type ultrasonic disperser at an output of 20,000 J / s to produce pretreated nanocellulose.

[0450] <Example> Example 1 Manufacturing of biodegradable polyester resin First stage: Pretreatment to obtain slurry As shown in Table 1, pretreated nanocellulose, 1,4-butanediol (1,4-BDO), and terephthalic acid (TPA) were mixed in a molar ratio (1,4-BDO:TPA) of 1.2:1 and added to a slurry tank (the bottom of the slurry tank was anchor-type, the height to the agitator was 40 mm, and it was equipped with three rotors) without a catalyst. At this time, the D50 of the terephthalic acid (TPA) was 120 μm.

[0451] Next, the mixture was pretreated by stirring at 60° C. and 100 rpm for 1 hour, and a slurry was obtained without phase separation.

[0452] Second step: obtaining prepolymer A mixture of about 274 parts by weight of the slurry obtained in the first step, about 28 parts by weight of 1,4-butanediol, and about 29.2 parts by weight of adipic acid was introduced into a reactor via a supply line, and 250 ppm of titanium-based catalyst tetrabutyl titanate (Dupont, manufactured by Tyzor TnBT) was added thereto. 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 removed.

[0453] A mixture of about 16.4 parts by weight of slurry, about 118 parts by weight of 1,4-butanediol (1,4-BDO), and about 146 parts by weight of adipic acid (AA) was added to the reaction product, and 200 ppm of titanium-based catalyst tetrabutyl titanate (Dupont, manufactured by Tyzor TnBT) based on the total weight of the reaction product and the additional mixture was added. 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 removed, producing a prepolymer having a number average molecular weight of 1300 g / mol.

[0454] Third step: Polycondensation reaction The prepolymer was stabilized for about 10 minutes by adding 5 wt% of the prepared oligomer (based on the total weight of the prepolymer), 400 ppm of a titanium-based catalyst, tetrabutyl titanate (Dupont, manufactured by Tyzor TnBT), and 500 ppm of a triethylene phosphate stabilizer. The reaction mixture was then heated to 250°C and subjected to a condensation polymerization reaction at 0.5 torr for 4 hours to produce a polymer with an average water content of 55,000 g / mol.

[0455] Thereafter, the polymer was cooled to 5° C. and cut with a pellet cutter to obtain biodegradable polyester resin pellets.

[0456] Examples 2 to 7 and Comparative Examples 1 to 2 As shown in Tables 1 and 2 below, the reactant compositions and process conditions for the first esterification reaction and the second esterification reaction are different. Except for the above contents and processes, the other processes were substantially the same as in Example 1.

[0457] Manufacturing of biodegradable polyester sheets Two Teflon sheets were prepared, and a stainless steel (SUS) frame (12cm x 12cm) was placed on one of the Teflon sheets. Approximately 7g of the polyester resin pellets were placed in the frame (12cm x 12cm), covered with another Teflon sheet, and placed in the center of a hot press (manufacturer: Withrap, model: WL1600SA) with a surface area of approximately 25cm x 25cm. This was maintained at approximately 210°C under approximately 10MPa of pressure for approximately 3 minutes, and then removed. The sheet was immediately cooled in water at approximately 20°C for approximately 30 seconds to produce a biodegradable polyester sheet with an area of approximately 10cm x 10cm and a thickness of approximately 300µm.

[0458] Manufacturing of biodegradable polyester film The biodegradable polyester resin pellets were dried at 80°C for 5 hours and then melt-extruded at 160°C using a blown film extrusion line (manufactured by Yujin Engineering) to produce a biodegradable polyester film with a thickness of 50 μm.

[0459] [Table 1]

[0460] [Table 2]

[0461] <Evaluation example> Evaluation Example 1: Average particle size (D50) and standard deviation <Average particle size (D50) and standard deviation of aromatic dicarboxylic acid> The average particle size (D50) and standard deviation (SD) of aromatic dicarboxylic acid (TPA or DMT) were determined using a particle size analyzer Microtrac S3500 (Microtrac Inc.) under the following conditions for particle size distribution (PSD).

[0462] Usage environment -Temperature: 10~35℃, Humidity: 90%RH, non-condensing maximum -The average particle size distribution, D50 and SD, were measured.

[0463] The standard deviation means the square root of the variance and can be calculated using software.

[0464] <Particle size of nanocellulose> The particle size and particle size deviation of nanocellulose were measured using dynamic light scattering (DLS) at a temperature of 25°C and a measurement angle of 175° using a Zetasizer Nano ZS (manufacturer: Marven). The peak value derived from the polydispersity index (PdI) with a confidence interval of 0.5 was used to measure the particle size.

[0465] Evaluation example 2: Degree of hydrolysis The biodegradable polyester resins prepared in the examples and comparative examples were immersed in water (100% RH) at 80°C, and then subjected to an accelerated water dispersibility test.

[0466] Specifically, 5 g of the polyester resins of the Examples and Comparative Examples were added to 500 mL of deionized water (DI Water), and the container was sealed with a stopper to prevent the water from evaporating. The accelerated hydrolysis test was then carried out in a convection (hot air) oven at 80°C. The humidity environment for the biodegradable polyester sheet was the same as that of 100% RH, since it was immersed in water.

[0467] The number average molecular weights of the polyester resins of the examples and comparative examples were measured after a certain period of time using gel permeation chromatography (GPC). The difference between the initial number average molecular weight and the number average molecular weight after a certain period of time was divided by the initial number average molecular weight to calculate the degree of hydrolysis.

[0468] The GPC equipment and measurement conditions are as follows:

[0469] Sample pretreatment: Dissolve 0.035 mg of PBAT chip in 1.5 ml of THF. Measurement device: Waters E2695 Flow rate: 1ml / min in THF Injection volume: 50μl Column temperature: 40℃ Detector:ELSD Column: Styragel Column HR 5E, HR4, HR2

[0470] Evaluation example 3: Biodegradability The biodegradable polyester resins produced in the Examples and Comparative Examples were mixed with the following compost and subjected to an accelerated biodegradation test at a temperature of 60°C and a humidity of 90%.

[0471] The number average molecular weights of the polyester resins of the Examples and Comparative Examples were measured after a certain period of time using gel permeation chromatography (GPC). The difference between the initial number average molecular weight and the number average molecular weight after a certain period of time was divided by the initial number average molecular weight to calculate the biodegradability.

[0472] compost Manufacturer: TaeheungF&G Product name: Chiseido (by-product fertilizer, Grade 1 compost) Compost components: 40 wt% pig manure, 15 wt% chicken manure, 37 wt% sawdust, 5 wt% zeolite, 3 wt% microbial preparation

[0473] Evaluation Example 4: Nuclear Magnetic Resonance Spectroscopy Approximately 5 mg of a sample was prepared from the biodegradable polyester resin composition of each of the examples and comparative examples, and the sample was dissolved in CDCl3. Then, the solution was analyzed at room temperature using a nuclear magnetic resonance (NMR) analyzer (JEOL, 500 MHz, 90° pulse). 1 H-NMR analysis was performed, and then the peaks of the terephthalic acid, the adipic acid, and the 1,4-butanediol were integrated in the obtained NMR data.

[0474] Equipment: Manufactured by JEOL, JNM-LA3000 Pulse: approx. 90° Repeat time: approx. 4 seconds Accumulation count: 8 measurements Temperature: Approximately 25℃

[0475] Evaluation Example 5: Glass transition temperature, crystallization temperature and melting point Using a differential scanning calorimeter (DSC, TA Instruments Q500), 4 mg of sample was placed in an aluminum pan and heated from 40°C to 180°C at a rate of 10°C / min, followed by isothermal heating for 5 minutes to remove the primary thermal history. The sample was then cooled from 180°C to -50°C at a rate of 10°C / min, followed by isothermal heating for 5 minutes to remove the primary thermal history. The biodegradable polyester resin was then heated from -50°C to 180°C at a rate of 10°C / min, and the endothermic and exothermic heat changes of the biodegradable polyester resin were measured. During the heating process, the crystallization temperature (Tc), glass transition temperature (Tg), and melting point (Tm) were determined.

[0476] Evaluation Example 6: Young's modulus and elongation at break The polyester sheets of approximately 300 μm in thickness manufactured in the examples and comparative examples were cut into test pieces based on ASTM D638V type. Test pieces were then made using an Instron universal testing machine (UTM, model 4206-001) at a tensile speed of 100 mm / min, and the Young's modulus (kgf / mm) was measured using a program installed in the equipment. 2 = 9.8 MPa) and elongation at break were measured.

[0477] The biodegradability of the examples and comparative examples was measured as shown in Table 3 below.

[0478] [Table 3]

[0479] The degree of hydrolysis was measured as set forth in Table 4 below.

[0480] [Table 4]

[0481] As shown in Table 5 below, 1 The H-NMR peaks and peak areas were measured.

[0482] [Table 5]

[0483] The soft segment ratio, crystallization temperature (Tc), glass transition temperature (Tg), melting point (Tm), Young's modulus, and elongation at break were calculated as shown in Tables 6 and 7 below.

[0484] [Table 6]

[0485] [Table 7]

[0486] As shown in Tables 3 to 7, the biodegradable polyester resin compositions according to the examples have appropriate biodegradability and hydrolysis degree. Furthermore, the biodegradable polyester resin compositions according to the examples may have high biodegradability, appropriate crystallization temperature, glass transition temperature, and melting point, and may also have appropriate mechanical properties. [Industrial Applicability]

[0487] The examples can be used for biodegradable resin compositions, films and molded articles.

Claims

1. The polyester resin includes a diol, an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid, The polyester resin has a soft segment ratio of 0.21 to 0.29, The ratio of the soft segment is the ratio of the diol bonded between the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid, Biodegradable polyester resin composition.

2. The ratio of the soft segment is 0.21 to 0.

28. The biodegradable polyester resin composition according to claim 1.

3. The ratio of the soft segment is 0.25 to 0.

28. The biodegradable polyester resin composition according to claim 1.

4. 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 polyester resin composition according to claim 1.

5. a ratio of the diol bonded between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid to the diol is 0.4 to 0.59; The biodegradable polyester resin composition according to claim 1.

6. The crystallization temperature is 38°C to 58°C. The biodegradable polyester resin composition according to claim 1.

7. The melting point is 70°C to 130°C, and the glass transition temperature is -50°C to -15°C. The biodegradable polyester resin composition according to claim 6.

8. The Young's modulus measured by the following measurement method is 25 MPa to 60 MPa. The biodegradable polyester resin composition according to claim 7. [Measurement method] The biodegradable polyester resin composition is dried at a temperature of 80°C, placed in a stainless steel frame, and compressed at a temperature of 210°C and a pressure of 10 MPa for 3 minutes to produce a polyester sheet having a thickness of 300 μm. The Young's modulus of the polyester sheet is measured at room temperature.

9. The breaking elongation measured by the following measurement method is about 800% to about 1100%. The biodegradable polyester resin composition according to claim 8. [Measurement method] The breaking elongation of the polyester sheet is measured at room temperature.

10. The polyester resin includes a diol, an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid, The polyester resin has a soft segment ratio of 0.21 to 0.29, The ratio of the soft segment is the ratio of the diol bonded between the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid, Biodegradable polyester film.

11. The ratio of the soft segment is 0.21 to 0.

28. The biodegradable polyester film according to claim 10.

12. a ratio of the diol bonded between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid to the diol is 0.4 to 0.59; The biodegradable polyester film according to claim 10.

13. a ratio of the diol bonded between the aromatic dicarboxylic acid and the aromatic dicarboxylic acid to the diol is 0.21 to 0.29; The biodegradable polyester film according to claim 10.

14. The crystallization temperature is 38°C to 58°C. The biodegradable polyester film according to claim 10.

15. The melting point is 70°C to 130°C, and the glass transition temperature is -50°C to -15°C. The biodegradable polyester film according to claim 14.

16. Young's modulus is 25 MPa to 60 MPa; The biodegradable polyester film according to claim 15.

17. The polyester resin includes a diol, an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid, The polyester resin has a soft segment ratio of 0.21 to 0.29, The ratio of the soft segment is the ratio of the diol bonded between the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid, Biodegradable molded products.

18. a ratio of the diol bonded between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid to the diol is 0.4 to 0.59; The biodegradable molded article according to claim 17.

19. a ratio of the diol bonded between the aromatic dicarboxylic acid and the aromatic dicarboxylic acid to the diol is 0.21 to 0.29; The biodegradable molded article according to claim 18.

20. Young's modulus is 25 MPa to 60 MPa; The biodegradable molded article according to claim 17.

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