Biodegradable resin composition and biodegradable molded article

Abstract

This invention provides biodegradable resin compositions and biodegradable molded articles. The invention provides a biodegradable resin composition comprising: a first biodegradable resin having a glass transition temperature (Tg) of -15 ºC or lower, and an inorganic filler, wherein the molding shrinkage of the biodegradable resin sample, measured according to measurement method 1 in the specification, is 1.0% or lower.

Description

Technical Field

[0001] This invention relates to biodegradable resin compositions and biodegradable molded articles comprising the same. Prior Technology

[0002] Recently, with increasing concern about environmental issues, there is a need to address the disposal of various household items, especially disposable products. Specifically, petroleum-based polymer materials are inexpensive and have excellent processability, making them widely used in the manufacture of various products such as films, fibers, packaging materials, bottles, and containers. However, products made from petroleum-based polymer materials release harmful substances when incinerated at the end of their lifespan. Furthermore, depending on the type of product, complete natural decomposition can take hundreds of years.

[0003] To overcome these limitations of petroleum-based polymer materials, research is actively underway on biodegradable resins that decompose within a relatively short period. Polylactic acid (PLA), polybutylene terephthalate (PBAT), and polybutylene succinate (PBS) have been introduced as biodegradable resins.

[0004] However, PLA lacks flexibility, and PBAT has poor mechanical properties, thus limiting its applications. To address these issues, US Patent No. 9096758 describes mixing PBAT as a biodegradable resin composition with a small amount of inorganic filler. However, due to its low mechanical properties and poor moisture resistance, it still has limitations in replacing traditional petroleum-based polymer materials.

[0005] Existing technical documents [Patent Literature] (Patent Document 1) US Patent No. 9096758. Summary of the Invention

[0006] [Technical Issues]

[0007] Therefore, the present invention was made in view of the above-mentioned problems, and one object of the present invention is to provide a biodegradable resin composition having excellent dimensional stability and mechanical properties, and a biodegradable molded article comprising the thereof. [Technical Solutions]

[0008] According to aspects of the present invention, the above and other objectives can be achieved by providing a biodegradable resin composition comprising: The first biodegradable resin has a glass transition temperature (Tg) of -15 ºC or lower; and Inorganic packing, The molding shrinkage rate of the biodegradable resin sample, measured according to the following measurement method 1, is 1.0% or lower: [Measurement Method 1] 1) Place the biodegradable resin composition between a pair of molds with dimensions of 60 mm in the transverse direction and 60 mm in the longitudinal direction, and then manufacture a biodegradable resin sample with an average thickness of 2 mm at 180°C under a pressure of 20 MPa. 2) Remove the biodegradable resin sample from the mold and calculate the transverse shrinkage rate and longitudinal shrinkage rate of the biodegradable resin sample after 24 hours. 3) The molding shrinkage rate of biodegradable resin samples is calculated according to the following equation 1: [Equation 1] Molding shrinkage rate (%) of biodegradable resin sample = (transverse shrinkage rate + longitudinal shrinkage rate) / 2 The lateral shrinkage rate is calculated using Equation 2, and the longitudinal shrinkage rate is calculated using Equation 3. [Equation 2] Transverse shrinkage rate (%) = (Transverse length of the biodegradable resin sample after 24 hours (mm) / 60 mm) × 100 [Equation 3] Longitudinal shrinkage rate (%) = (longitudinal length of the biodegradable resin sample after 24 hours (mm) / 60 mm) × 100.

[0009] In embodiments of the present invention, the molding shrinkage rate of the biodegradable resin sample may be 0.5% or lower.

[0010] In embodiments of the present invention, the content of inorganic filler can be from 10 wt% to 90 wt% based on the total weight of the biodegradable resin composition.

[0011] In embodiments of the present invention, the biodegradable resin composition may include a first biodegradable resin and an inorganic filler in a weight ratio of 90:10 to 30:70.

[0012] In embodiments of the present invention, the biodegradable resin composition may include a second biodegradable resin different from the first biodegradable resin, and the second biodegradable resin has a glass transition temperature (Tg) of 50 ºC or higher.

[0013] In an embodiment of the present invention, the second biodegradable resin may have a flexural strength of 50 MPa or higher, according to ASTM D790 standard.

[0014] In embodiments of the present invention, the flexural modulus of the second biodegradable resin may be 2,500 MPa or higher, according to ASTM D790 standard.

[0015] In embodiments of the present invention, the biodegradable resin composition may include a first biodegradable resin and a second biodegradable resin in a weight ratio of 90:10 to 10:90.

[0016] In an embodiment of the present invention, the first coefficient of thermal expansion of the biodegradable resin sample measured according to the following measurement method 2 can be 75. Up to 290 : [Measurement Method 2] 1) Cut the biodegradable resin sample into dimensions of 20 mm in the transverse direction × 4 mm in the longitudinal direction × 0.7 mm in the thickness to prepare a biodegradable resin sample. 2) Using a thermomechanical analyzer, the first coefficient of thermal expansion of the biodegradable resin sample was measured in the range of 10°C to 40°C while heating from 0°C to 100°C at a rate of 5°C / min.

[0017] In an embodiment of the present invention, the second coefficient of thermal expansion of the biodegradable resin sample measured according to the above-described measurement method 2 in the range of 80 ºC to 100 ºC can be 100. Up to 1,000 .

[0018] In embodiments of the present invention, the specific gravity of the biodegradable resin particles, measured according to the following measurement method 3, can be from 1.30 to 2.00: [Measurement Method 3] 1) A biodegradable resin composition is extruded at 175 ºC and then cooled at 5 ºC to produce biodegradable resin particles. 2) Measure the specific gravity of biodegradable resin particles at 23 °C according to ASTM D792 standard.

[0019] According to another aspect of the present invention, a biodegradable molded article is provided, comprising: The first biodegradable resin has a glass transition temperature (Tg) of -15 ºC or lower; and Inorganic packing, The molding shrinkage rate of the biodegradable resin sample, measured according to the following measurement method 1, is 1.0% or lower: [Measurement Method 1] 1) Place the biodegradable resin composition between a pair of molds with dimensions of 60 mm in the transverse direction and 60 mm in the longitudinal direction, and then manufacture a biodegradable resin sample with an average thickness of 2 mm at 180°C under a pressure of 20 MPa. 2) Remove the biodegradable resin sample from the mold and calculate the transverse shrinkage rate and longitudinal shrinkage rate of the biodegradable resin sample after 24 hours. 3) The molding shrinkage rate of biodegradable resin samples is calculated according to the following equation 1: [Equation 1] Molding shrinkage rate (%) of biodegradable resin sample = (transverse shrinkage rate + longitudinal shrinkage rate) / 2 In Equation 1, the lateral shrinkage rate is calculated by Equation 2, and the longitudinal shrinkage rate is calculated by Equation 3. [Equation 2] Transverse shrinkage rate (%) = (Transverse length of the biodegradable resin sample after 24 hours (mm) / 60 mm) × 100 [Equation 3] Longitudinal shrinkage rate (%) = (longitudinal length of the biodegradable resin sample after 24 hours (mm) / 60 mm) × 100.

[0020] In embodiments of the present invention, the biodegradable molded articles can be nonwoven fabrics, vacuum-formed sheets, blow-molded articles, or injection-molded articles. [Beneficial Effects]

[0021] The biodegradable resin composition according to the invention comprises a biodegradable resin whose glass transition temperature is adjusted to a specific range or lower, thereby improving biodegradability, tensile strength and elongation, and the biodegradable molded article comprising the biodegradable resin composition can be readily decomposed upon disposal.

[0022] Furthermore, the biodegradable resin composition according to the present invention comprises a biodegradable resin whose glass transition temperature is adjusted to a specific range or lower, and at the same time, the molding shrinkage of the biodegradable resin composition can be controlled within a specific range or lower, thereby minimizing volume change during injection molding and improving flexural strength, flexural modulus, elongation at break and impact strength, thereby improving mechanical properties.

[0023] Furthermore, the biodegradable resin composition according to the present invention comprises a high content of inorganic fillers, which can improve dimensional stability at room temperature and high temperature, and due to its high specific gravity, it can be more appropriately applied to container products that require preservation functions, durability, etc. Implementation

[0024] The structural or functional descriptions of the embodiments disclosed in this specification or application are merely for the purpose of explaining the embodiments of the technical concept of the present invention. The embodiments of the technical concept of the present invention can be implemented in various forms other than those disclosed in this specification or application, and should not be construed as the technical concept of the present invention being limited to the embodiments described in this specification or application.

[0025] In this specification or application, when a component is "included," it means that only that component is included, or that the component may also include other components, unless otherwise disclosed. Furthermore, it should be understood that, unless otherwise stated, in all cases, all numerical ranges of physical property values, dimensions, etc., representing components described in this specification or application are modified by the term "about."

[0026] Furthermore, in this specification or application, "ppm" is based on weight.

[0027] In this specification or application, “A and / or B” means “A, B or A and B”.

[0028] Below, a biodegradable resin composition according to the present invention and a biodegradable molded article comprising the thereof are described.

[0029] The biodegradable resin composition according to the present invention comprises a first biodegradable resin having a glass transition temperature (Tg) of -15 ºC or lower, and an inorganic filler, and the molding shrinkage of the biodegradable resin sample, measured according to the following measurement method 1, is 1.0% or lower: [Measurement Method 1] 1) Place the biodegradable resin composition between a pair of molds with dimensions of 60 mm in the transverse direction and 60 mm in the longitudinal direction, and then manufacture a biodegradable resin sample with an average thickness of 2 mm at 180°C under a pressure of 20 MPa. 2) Remove the biodegradable resin sample from the mold and calculate the transverse shrinkage rate and longitudinal shrinkage rate of the biodegradable resin sample after 24 hours. 3) The molding shrinkage rate of biodegradable resin samples is calculated according to the following equation 1: [Equation 1] Molding shrinkage rate (%) of biodegradable resin sample = (transverse shrinkage rate + longitudinal shrinkage rate) / 2 In Equation 1, the lateral shrinkage rate is calculated by Equation 2, and the longitudinal shrinkage rate is calculated by Equation 3. [Equation 2] Transverse shrinkage rate (%) = (Transverse length of the biodegradable resin sample after 24 hours (mm) / 60 mm) × 100 [Equation 3] Longitudinal shrinkage rate (%) = (Longitudinal length of the biodegradable resin sample after 24 hours (mm) / 60 mm) × 100

[0030] The biodegradable resin composition includes a first biodegradable resin having a glass transition temperature (Tg) of -15 ºC or lower. The glass transition temperature of the first biodegradable resin may be -15ºC or lower, -15ºC to -50ºC, -20ºC to -50ºC, -20ºC to -48ºC, -25ºC to -45ºC, or -26ºC to -42ºC.

[0031] To perform the first thermal history elimination process, the glass transition temperature (Tg) was raised from 40 ºC to 180 ºC at a rate of 10 ºC / min using a differential scanning calorimeter (DSC), then held isothermally for 5 minutes, and the first endothermic temperature was measured. The cooling process was performed by cooling from 180 ºC to -50 ºC at a rate of 10 ºC / min and holding isothermally for 5 minutes. The first endothermic temperature was then measured while heating from -50 ºC to 180 ºC at a rate of 10 ºC / min.

[0032] The first biodegradable resin may include diols, aromatic dicarboxylic acids, and aliphatic dicarboxylic acids.

[0033] The first biodegradable resin may include a first repeating unit and a second repeating unit. The first repeating unit may include a diol component and an aromatic dicarboxylic acid component, and the second repeating unit may include a diol component and an aliphatic dicarboxylic acid component.

[0034] The number of the first repeating units can be 100 to 620, 150 to 600, 150 to 550, 150 to 500, 170 to 480, or 171 to 476.

[0035] The number of second repeating units can be 120 to 800, 150 to 800, 170 to 700, 200 to 600, 230 to 600, 230 to 550, 230 to 530, 238 to 524, 250 to 550, 280 to 530, or 300 to 500.

[0036] When this range is met, the glass transition temperature (Tg) of the first biodegradable resin can be adjusted to -15 ºC or lower, thereby reducing the crystallinity of the biodegradable resin composition and thus improving tensile strength and elongation.

[0037] The diol component may include 1,4-butanediol or its derivatives. Based on the total molar number of the diol component, the amount of 1,4-butanediol or its derivatives that the diol component may include is 95 mol% or more, 97 mol% or more, 98 mol% or more, 99 mol% or more, or 100 mol%. The diol component can improve biodegradability, flexibility, and strength by including 1,4-butanediol or its derivatives. When the diol component consists only of 1,4-butanediol, the improvement in biodegradability and strength can be maximized.

[0038] The diol component may further include a second diol that is different from the first diol, which is 1,4-butanediol or a derivative thereof. The second diol may include one or more selected from the group consisting of propylene glycol, hexanediol, cyclohexanediol, and ethylene glycol. Specifically, the second diol may include one or more selected from the group consisting of: 1,3-propanediol, 1,2-propanediol, 1,2-hexanediol, 1,3-hexanediol, 1,4-hexanediol, 1,6-hexanediol, 2,3-hexanediol, 2,4-hexanediol, 2,5-hexanediol, 2,6-hexanediol, 3,4-hexanediol, 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, and ethylene glycol. Based on the total molar number of the diol component, the amount of the second diol that the diol component may include is 5 mol% or less, 3 mol% or less, 2 mol% or less, or 1 mol% or less.

[0039] The aromatic dicarboxylic acid component may include one or more selected from the group consisting of terephthalic acid, dimethyl terephthalic acid, and their derivatives. Specifically, the aromatic dicarboxylic acid component may be terephthalic acid or dimethyl terephthalic acid. Based on the total molar number of the dicarboxylic acid component, the amount of aromatic dicarboxylic acid component that the dicarboxylic acid component may include is: 15 mol% or more, 30 mol% or more, 45 mol% or more, 50 mol% or more, or 75 mol% or more; as a particular example, 30 mol% to 90 mol%, 35 mol% to 80 mol%, 40 mol% to 75 mol%, 45 mol% to 65 mol%, or 45 mol% to 55 mol%.

[0040] The aliphatic dicarboxylic acid component may include one or more selected from the group consisting of adipic acid, succinic acid, and their derivatives. Specifically, the aliphatic dicarboxylic acid component may be adipic acid or succinic acid. Based on the total molar number of the dicarboxylic acid component, the amount of aliphatic dicarboxylic acid component that the dicarboxylic acid component may include is: 15 mol% or more, 30 mol% or more, 45 mol% or more, 50 mol% or more, or 75 mol% or more; as a particular example, 30 mol% to 90 mol%, 35 mol% to 80 mol%, 40 mol% to 75 mol%, 45 mol% to 65 mol%, or 45 mol% to 55 mol%.

[0041] The molar ratio of the aromatic dicarboxylic acid component to the aliphatic dicarboxylic acid component can be 0.5 to 1.5:1, 0.6 to 1.5:1, 0.6 to 1.4:1, 0.7 to 1.4:1, 0.7 to 1.3:1 or 0.8 to 1.2:1.

[0042] The molar ratio of the diol component to the dicarboxylic acid component can be 0.5 to 2:1, 0.5 to 1.9:1, 0.5 to 1.8:1, 0.5 to 1.7:1, 0.6 to 1.7:1, 0.6 to 1.6:1, 0.7 to 1.5:1, or 0.9 to 1.2:1. When this range is met, the biodegradability, strength, and processability of the biodegradable resin composition can be improved without discoloration such as yellowing.

[0043] Biodegradable resins may include polybutylene terephthalate (PBAT), wherein the first repeating unit may include a diol component and an aromatic dicarboxylic acid component, and the second repeating unit may include a diol component and an aliphatic dicarboxylic acid component.

[0044] In particular, polybutylene adipate terephthalate may comprise units represented by the following formula 1: [Formula 1] In Equation 1, m can be from 1 to 20, and n can be from 1 to 20.

[0045] The biodegradable resin composition may include a second biodegradable resin, different from the first biodegradable resin, and the second biodegradable resin may have a glass transition temperature (Tg) of 50 ºC or higher. The glass transition temperature of the second biodegradable resin may be 50 ºC or higher, 50 ºC to 80 ºC, 50 ºC to 75 ºC, 50 ºC to 70 ºC, 55 ºC to 70 ºC, or 55 ºC to 65 ºC. When this range is met, the polymer chain flowability can be reduced during the cooling of the biodegradable resin composition, thereby minimizing volume change during injection molding of the biodegradable resin composition.

[0046] According to ASTM D790, the flexural strength of the second biodegradable resin can be 50 MPa or higher, 60 MPa or higher, 70 MPa or higher, 80 MPa or higher, 100 MPa or higher, or 100 MPa or higher up to 150 MPa or lower.

[0047] According to ASTM D790, the flexural modulus of the second biodegradable resin may be 2,500 MPa or greater, 2,800 MPa or greater, 3,000 MPa or greater, 3,200 MPa or greater, 3,300 MPa or greater, or 3,300 MPa or greater up to 4,000 MPa or less.

[0048] When this range is met, the mechanical properties of the first biodegradable resin, such as flexural strength and flexural modulus, can be supplemented.

[0049] The biodegradable resin composition may include a first biodegradable resin to a second biodegradable resin in a weight ratio of 90:10 to 10:90, 80:20 to 10:90, 70:30 to 10:90, 60:40 to 10:90, or 60:40 to 20:90. When this range is met, the elongation at break and impact strength are excellent, thus improving brittleness and processability. Furthermore, flexural strength and flexural modulus can also be improved.

[0050] According to ASTM D790, the flexural strength of a biodegradable resin composition can be 9 MPa or higher, 10 MPa or higher, 20 MPa or higher, 25 MPa or higher, 30 MPa or higher, or 9 MPa or higher up to 50 MPa or lower.

[0051] According to ASTM D790, the flexural modulus of biodegradable resin compositions may be 150 MPa or greater, 200 MPa or greater, 250 MPa or greater, 300 MPa or greater, 800 MPa or greater, or 310 MPa or greater up to 1,000 MPa or less.

[0052] The weight-average molecular weight of the biodegradable resin composition can depend on the weight ratio of the first biodegradable resin to the second biodegradable resin. Furthermore, the flexural strength and / or flexural modulus of the biodegradable resin composition can be varied according to the weight-average molecular weight and / or degree of bonding between the first and second biodegradable resins. Additionally, the molding shrinkage of the biodegradable resin sample can be adjusted based on changes in the flexural strength and / or flexural modulus of the biodegradable resin composition.

[0053] The second biodegradable resin may include one or more selected from the group consisting of: polybutylene terephthalate (PBAzT), polybutylene sebacate (PBSeT) and polybutylene terephthalate (PBST), polyhydroxyalkanoates (PHA) and polylactic acid (PLA).

[0054] Polylactic acid (PLA) can be a stereocomplex crystal with a high melting point. Furthermore, PLA can be formed by solution mixing or melt mixing of poly-L-lactic acid and poly-D-lactic acid.

[0055] In particular, polylactic acid can include units represented by the following chemical formula 2: [Equation 2]

[0056] Polylactic acid (PLA) can be a polymer comprising L-lactic acid units and / or D-lactic acid units. PLA may include poly-L-lactic acid and / or poly-D-lactic acid.

[0057] When a biodegradable resin composition is used in an injection-molded article, the content of poly-D-lactic acid in polylactic acid may be greater than about 0 wt% and about 2 wt% or less, greater than about 0 wt% and about 1.9 wt% or less, greater than about 0 wt% and about 1.8 wt% or less, or greater than about 0 wt% and about 1.7 wt% or less.

[0058] The biodegradable resin composition is used in extruded products such as nonwoven fabrics, vacuum-formed sheets or blow-molded articles, wherein the poly-D-lactic acid content in polylactic acid may be 3 wt% or more to 5 wt% or less, 3.5 wt% or more to 5 wt% or less, 3.5 wt% or more to 4.8 wt% or less, or 3.8 wt% or more to 4.8 wt% or less.

[0059] When this range is met, both thermal and mechanical properties are excellent, and the material can provide adequate flowability in the required processes, thereby improving processability.

[0060] Poly-L-lactic acid (PLA) can be a polymer primarily comprising L-lactic acid units. PLA may include L-lactic acid units in amounts of about 90 mol% to about 100 mol%, about 91 mol% to about 100 mol%, about 92 mol% to about 100 mol%, about 93 mol% to about 100 mol%, about 94 mol% to about 100 mol%, about 95 mol% to about 100 mol%, about 96 mol% to about 100 mol%, or about 97 mol% to about 100 mol%. PLA may include D-lactic acid units and / or units other than lactic acid. Poly-L-lactic acid may include D-lactic acid units and / or units other than lactic acid in amounts of about 0 mol% to about 10 mol%, about 0 mol% to about 9 mol%, about 0 mol% to about 8 mol%, about 0 mol% to about 7 mol%, about 0 mol% to about 6 mol%, about 0 mol% to about 5 mol%, or about 0 mol% to about 3 mol%.

[0061] Poly-D-lactic acid (PDLA) can be a polymer primarily comprising D-lactic acid units. The D-lactic acid units in PDLA may comprise about 90 mol% to about 100 mol%, about 91 mol% to about 100 mol%, about 92 mol% to about 100 mol%, about 93 mol% to about 100 mol%, about 94 mol% to about 100 mol%, about 95 mol% to about 100 mol%, or about 97 mol% to about 100 mol%. PDLA may also comprise L-lactic acid units and / or units other than lactic acid. The L-lactic acid units and / or units other than lactic acid in PDLA may comprise about 0 mol% to about 10 mol%, about 0 mol% to about 9 mol%, about 0 mol% to about 8 mol%, about 0 mol% to about 7 mol%, about 0 mol% to about 6 mol%, about 0 mol% to about 5 mol%, or about 0 mol% to about 3 mol%.

[0062] Units other than lactic acid may include units derived from dicarboxylic acids, polyols, hydroxycarboxylic acids, and lactones, which have functional groups capable of forming two or more ester bonds, as well as units derived from various polyesters, polyethers, and polycarbonates composed of these various components.

[0063] For example, dicarboxylic acids can include succinic acid, adipic acid, azirionic acid, sebacic acid, terephthalic acid, isophthalic acid, etc. Polyols can include aliphatic polyols such as ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, octanediol, glycerol, sorbitol, neopentyl glycol, diethylene glycol, triethylene glycol, polyethylene glycol, and polypropylene glycol, as well as aromatic polyols obtained by adding ethylene oxide to bisphenols, etc.

[0064] Hydroxycarboxylic acids can include glycolic acid, hydroxybutyric acid, etc. For example, lactones can include glycolide, ε-caprolactone glycolide, ε-caprolactone, β-proprolactone, δ-butyrolactone, β- or γ-butyrolactone, neopentyl lactone, δ-pentyl lactone, etc.

[0065] Polylactic acid (PLA) is commercially available from Biomer Corporation under the name BIOMER™ L9000. Additionally, PLA is commercially available from Natureworks LLC (NATUREWORKS®) or Mitsui Chemical (LACEA™). Furthermore, PLA is described in U.S. Patent Nos. 4,797,468; 5,470,944; 5,770,682; 5,821,327; 5,880,254; and 6,326,458, the entire contents of which are incorporated herein by reference for all purposes.

[0066] Polylactic acid can be modified using surface treatment agents.

[0067] The surface of polylactic acid (PLA) can be modified with a surface treatment agent. The biodegradable resin composition containing PLA can, due to the surface treatment agent, improve compatibility with the first biodegradable resin and inhibit the exudation of PLA from the surface of the produced molded article.

[0068] Surface treatment agents may include amide groups. Surface treatment agents may include fatty acid amides. Surface treatment agents including amide groups can readily bind to the functional groups of polylactic acid, making the surface of polylactic acid easier to modify. Therefore, compatibility with the first biodegradable resin can be improved, and exudation can be further suppressed.

[0069] Surface-modified polylactic acid can be prepared by the following methods.

[0070] A surface treatment agent is added to polylactic acid (PLA), and the PLA and the surface treatment agent are stirred so that the surface treatment agent can bind to the PLA surface.

[0071] The stirring temperature can be from the melting point of the surface treatment agent to the melting point of the surface treatment agent +50 ºC. The amount of surface treatment agent added relative to 100 parts by weight of polylactic acid can be 0.1 parts by weight to 5 parts by weight, 0.1 parts by weight to 4 parts by weight, 0.1 parts by weight to 3 parts by weight, or 0.5 parts by weight to 3 parts by weight.

[0072] The mixing time can be from about 1 minute to about 60 minutes, from about 1 minute to about 50 minutes, from about 5 minutes to about 50 minutes, or from about 5 minutes to about 40 minutes.

[0073] Polyhydroxy fatty acid esters may include units represented by the following chemical formula 3: [Formula 3]

[0074] In chemical formula 3, R can be independently selected from groups of hydrogen atoms, hydrocarbon groups, heteroatoms and their combinations, n can be from 1 to 35,000 repeating units, and x can be an integer from 1 to 5.

[0075] Polyhydroxy fatty acid esters can be homopolymers or copolymers composed of at least one part selected from the group consisting of: 3-hydroxypropionate, 3-hydroxybutyrate, 3-hydroxyvalerate, 3-hydroxyhexanoate, 3-hydroxyheptanoate, 3-hydroxyoctanoate, 3-hydroxynonanoate, 3-hydroxydecanoate, 3-hydroxyundecanoate, 3-hydroxydodecanoate, and combinations thereof. Furthermore, at least one part may have the same or different numbers of repeating units.

[0076] Polyhydroxy fatty acid esters can be copolymers containing 3-hydroxybutyrate units and 3-hydroxyhexanoate units as the main constituent units.

[0077] Polyhydroxy fatty acid esters may include 80 mol% or more of 3-hydroxybutyrate units as a component. The amount of 3-hydroxybutyrate units that a polyhydroxy fatty acid ester may include is approximately 85 mol% or more.

[0078] Polyhydroxy fatty acid esters can be poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) copolymer resins or poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate) copolymer resins.

[0079] For example, polyhydroxyalkanoates can be produced using microorganisms such as *Alcaligenes eutrophus* AC 32 (internationally deposited under the Budapest Treaty, International Depository: Independent Administrative Corporation Industrial Technology Research Institute Patent Biological Deposit Center (6 Chuo 1-1, Tsukuba City, Ibaraki Prefecture, Japan), original deposit date: August 12, 1996, transferred on August 7, 1997, deposit number: FERM BP-6038, transferred from original deposit FERM P-15786, J. Bacteriol., 179, 4821 (1997)), which is created by introducing a PHA synthase gene derived from *Aeromonas caviae* into *Alcaligenes eutrophus*.

[0080] Polyhydroxyalkanoates (PHAs) are available on the market. Commercially available PHAs may include “NODAX” by Danimer Co., “ENMAT” by Tianan Biopolymer Co., “PHACT” by CJ Co., and “Aonilex X131N”, “Aonilex X131A”, “Aonilex 151A”, “Aonilex 151C”, “PHBH X331N”, “PHBH X131A”, “PHBH 151A”, and “PHBH 151C” by Kaneka Co.

[0081] The biodegradable resin composition includes an inorganic filler. The inorganic filler can be used as a carrier for a first biodegradable resin or both first and second biodegradable resins included in the biodegradable resin composition. Therefore, the crystallinity of the biodegradable resin composition can be controlled, thereby improving dimensional stability at room temperature and high temperature.

[0082] Based on the total weight of the biodegradable resin composition, the content of inorganic filler can be 10 wt% to 90 wt%, 20 wt% to 90 wt%, 30 wt% to 90 wt%, 40 wt% to 90 wt%, 40 wt% to 80 wt%, or 47 wt% to 70 wt%. When this range is met, dimensional stability at room temperature and high temperature can be improved, and it is also more suitable for cosmetic container products requiring durability due to the increased specific gravity.

[0083] The biodegradable resin composition may include a first biodegradable resin and an inorganic filler in a weight ratio of 90:10 to 30:70, 80:20 to 30:70, 70:30 to 30:70, or 60:40 to 30:70. When this range is met, the crystallinity of the biodegradable resin composition can be improved, thereby improving its dimensional stability at room temperature and high temperature.

[0084] Inorganic fillers can have specific surface areas ranging from 0.1 m² / g to 10.0 m² / g, 0.1 m² / g to 9.0 m² / g, 0.1 m² / g to 8.0 m² / g, 0.1 m² / g to 7.0 m² / g, 0.1 m² / g to 6.0 m² / g, 0.1 m² / g to 5.0 m² / g, 0.1 m² / g to 4.0 m² / g, or 0.1 m² / g to 3.0 m² / g. The specific surface area can be measured using nitrogen adsorption. When these ranges are met, the biodegradability of the biodegradable resin can be improved, and its processability can also be enhanced, as the inorganic filler can be dispersed within it.

[0085] Inorganic fillers can have average particle sizes of 0.1 µm to 10.0 µm, 0.1 µm to 9.0 µm, 0.1 µm to 8.0 µm, 0.1 µm to 7.0 µm, 0.1 µm to 6.0 µm, 0.1 µm to 5.0 µm, 0.1 µm to 4.0 µm, 0.1 µm to 3.0 µm, 1.0 µm to 5.0 µm, 1.0 µm to 4.0 µm, or 1.0 µm to 3.0 µm. The average particle size can be calculated based on the measurement of specific surface area obtained by air permeation using a specific surface area measuring device. Meeting these ranges can prevent an increase in viscosity when biodegradable resins and inorganic fillers are mixed and can improve fineness and uniformity.

[0086] The sphericity of the inorganic filler can be 0.30 to 0.95, 0.30 to 0.93, 0.30 to 0.90, 0.50 to 0.95, 0.50 to 0.93, 0.50 to 0.90, 0.60 to 0.95, 0.60 to 0.93, or 0.60 to 0.90. When this range is met, biodegradability is improved through the numerous micropores formed at the interface between the biodegradable resin and the inorganic filler. Furthermore, the strength and processability of the molded articles can be improved.

[0087] Inorganic fillers may include one or more selected from the group consisting of: calcium carbonate, magnesium carbonate, zinc oxide, titanium oxide, silica, alumina, kaolin, talc, mica, wollastonite, aluminum hydroxide, magnesium hydroxide, aluminum silicate, magnesium silicate, calcium silicate, aluminum sulfate, magnesium sulfate, calcium sulfate, magnesium phosphate, barium sulfate, silica, zeolite, diatomaceous earth, sericite, white sand, calcium sulfate, potassium titanate, bentonite, graphite, and ferrates.

[0088] Preferably, the inorganic filler may include calcium carbonate (CaCO3). Generally, when molded articles manufactured using biodegradable resin compositions undergo biodegradation, acidic components may be generated. These acidic components may react with calcium carbonate to produce CO2 and H2O, potentially further increasing the biodegradation rate of the molded article into molecular units. Furthermore, calcium carbonate can neutralize acidic components, reducing environmental impact and preventing soil acidification.

[0089] Calcium carbonate can be heavy calcium carbonate obtained by mechanically grinding or grading natural calcium carbonate containing CaCO3 as the main component, such as limestone, chalk, marble, shells and coral.

[0090] Calcium carbonate can be surface-treated with organic acids. Surface treatment of calcium carbonate with organic acids can improve the dispersibility of biodegradable resin compositions and enhance their reactivity with biodegradable resins. Surface treatment can be performed by physical methods such as plasma treatment and corona treatment, or by chemical methods using chemical reagents such as silane coupling agents, titanium coupling agents, and surfactants. Organic acids can include higher fatty acids, higher fatty acid esters, higher fatty acid amides, and higher fatty acids, such as calcium stearate.

[0091] Surface-treated calcium carbonate can be prepared by the following methods.

[0092] First, calcium carbonate powder can be prepared through a grinding process. Then, the calcium carbonate powder can be graded to obtain calcium carbonate of the desired fineness.

[0093] Next, calcium carbonate can be heated at approximately 200 °C to approximately 800 °C using a heating device selected from a kiln, electric furnace, or microwave oven. The heat treatment time can be approximately 5 minutes to approximately 30 minutes, approximately 7 minutes to approximately 15 minutes, or approximately 7 minutes to approximately 14 minutes. The heat treatment temperature can be approximately 250 °C to approximately 700 °C or approximately 300 °C to approximately 600 °C. By heat-treating calcium carbonate under the above conditions, moisture in the calcium carbonate can be easily removed, organic acids can easily combine with the surface of the calcium carbonate, and the agglomeration of calcium carbonate can be minimized.

[0094] Next, the surface of the heat-treated calcium carbonate can be treated by adding an organic acid. The processing temperature can be from 70 °C to about 130 °C. Based on 100 parts by weight of calcium carbonate, the amount of organic acid added can be from about 0.5 parts by weight to about 5 parts by weight, from about 0.5 parts by weight to about 4 parts by weight, from about 0.5 parts by weight to about 3 parts by weight, from about 0.5 parts by weight to about 2 parts by weight, from about 0.6 parts by weight to about 5 parts by weight, from about 0.6 parts by weight to about 4 parts by weight, from about 0.6 parts by weight to about 3 parts by weight, from about 0.6 parts by weight to about 2 parts by weight, from about 0.7 parts by weight to about 5 parts by weight, from about 0.7 parts by weight to about 4 parts by weight, from about 0.7 parts by weight to about 3 parts by weight, or from about 0.7 parts by weight to about 2 parts by weight. The processing time can be from about 1 minute to about 60 minutes, from about 10 minutes to about 30 minutes, or from about 5 minutes to about 20 minutes.

[0095] Next, the surface-treated calcium carbonate can undergo other processes such as grinding and grading the aggregate produced during the surface treatment process. In the surface-treated calcium carbonate, the content of organic acids, based on total weight, can be from about 0.1 wt% to about 3 wt%, from about 0.1 wt% to about 2 wt%, from about 0.1 wt% to about 1 wt%, from about 0.2 wt% to about 3 wt%, from about 0.2 wt% to about 2 wt%, from about 0.2 wt% to about 1 wt%, from about 0.3 wt% to about 3 wt%, from about 0.3 wt% to about 2 wt%, or from about 0.3 wt% to about 1 wt%.

[0096] Surface-treated calcium carbonate may be partially oxidized by organic acids. Surface-treated calcium carbonate may contain calcium oxide (CaO). Based on 100% by volume of surface-treated calcium carbonate particles, the proportion of calcium oxide can be 5% by volume or less, 4% by volume or less, 3% by volume or less, 2% by volume or less, 1% by volume or less, 0.01% by volume or more and 5% by volume or less, 0.01% by volume or more and 4% by volume or less, 0.01% by volume or more and 3% by volume or less, 0.01% by volume or more and 2% by volume or less, or 0.01% by volume or more and 1% by volume or less. The calcium oxide ratio can be measured by ethylenediaminetetraacetic acid (EDTA) titration according to JIS R 9011. When this range is met, the uniformity of the calcium carbonate surface can be improved, and the elution of organic acids from the calcium carbonate surface can be minimized, thereby improving hydrolysis resistance.

[0097] Biodegradable resin compositions may further include reinforcing agents. Reinforcing agents may be fibers derived from biomass. Reinforcing agents may include nanocellulose. Nanocellulose may be natural nanocellulose in gel or powder form. The dispersion stability, strength, and processability of biodegradable resins containing nanocellulose can be improved.

[0098] The nanocellulose has a diameter that can be 1 nm to 100 nm, 1 nm to 95 nm, 5 nm to 90 nm, 10 nm to 80 nm, 5 nm to 60 nm, or 15 nm to 60 nm. The nanocellulose has a length that can be 5 nm to 5 µm, 5 nm to 1 µm, 10 nm to 700 nm, 20 nm to 500 nm, 60 nm to 300 nm, 80 nm to 200 nm, or 100 nm to 250 nm. Meeting these ranges can further improve the strength and tear strength of the biodegradable resin composition.

[0099] Nanocellulose can be in the form of dry powder or gel, having aggregated secondary particles rather than single particles, and the size of the secondary particles can be 1 µm to 50 µm, 2 µm to 45 µm, or 5 µm to 50 µm. Nanocellulose can also be in the form of lyophilized powder to reduce its volume for easier storage and transportation.

[0100] The average particle size of nanocellulose can be 200 nm or smaller, 190 nm or smaller, or 185 nm or smaller. The particle size deviation can be 20% or smaller, 18% or smaller, or 16% or smaller. When this range is met, the dispersibility and durability of nanocellulose can be improved.

[0101] Nanocellulose can act as a nucleating agent, increasing the crystallization rate and crystallization temperature of biodegradable resin compositions. Nanocellulose may include one or more selected from the group consisting of cellulose nanocrystals, cellulose nanofibers, and microfibrillated cellulose. Cellulose nanocrystals or cellulose nanofibers are preferred in terms of strength and thermal properties.

[0102] Nanocellulose can provide UV protection and impart sufficient UV resistance, biodegradation rate, and hydrolysis rate to biodegradable resins. Nanocellulose can include one or more of the following: hydroxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, cellulose acetate, methylcellulose, ethylcellulose, propylcellulose, butylcellulose, pentylcellulose, hexylcellulose, and cyclohexylcellulose.

[0103] Nanocellulose can be pretreated using a bead mill or by ultrasound. Nanocellulose can be water-dispersed nanocellulose pretreated by a bead mill or by ultrasound.

[0104] Nanocellulose can be obtained by dispersing cellulose nanocrystals in water in the form of dry powder or gel with a particle size of 1 µm to 50 µm, followed by pretreatment of the cellulose nanocrystals using a bead mill or ultrasound. In this case, the number of nanocellulose particles may increase, thereby improving dispersibility.

[0105] Based on the total weight of the nanocellulose, it can be pretreated with 0.01 to 10 wt%, 0.05 to 8 wt%, 0.1 to 8 wt%, 0.5 to 6 wt%, or 0.7 to 6 wt% of a silane coupling agent. When this range is met, interfacial adhesion, dispersibility, and compatibility can be maximized. Therefore, the mechanical properties and durability of biodegradable resin compositions containing nanocellulose can be further improved.

[0106] Based on the total weight of the biodegradable resin, the biodegradable resin may include nanocellulose in the amounts of 0.01 to 3 wt%, 0.01 to 2.5 wt%, 0.05 to 2 wt%, 0.07 to 1.8 wt%, 0.1 to 1.2 wt%, 0.1 to 1 wt%, or 0.15 to 0.7 wt%. When this range is met, the biodegradability and strength of the biodegradable resin composition can be further improved.

[0107] Biodegradable resin compositions may include oligomers. The oligomers may have a weight-average molecular weight of about 400 g / mol to about 1,300 g / mol. Based on the weight of the biodegradable resin, the amount of oligomers that may be included in the biodegradable resin composition may be about 3,000 ppm to about 30,000 ppm, about 5,000 ppm to about 20,000 ppm, or about 5,000 ppm to about 15,000 ppm. The oligomers may be the reaction products of at least two of diols, aromatic dicarboxylic acids, and aliphatic dicarboxylic acids. The oligomers may be the reaction products of 1,4-butanediol, terephthalic acid, and adipic acid.

[0108] Biodegradable resin compositions may include plasticizers. Plasticizers impart processability or flexibility to molded articles made using biodegradable resin compositions. Plasticizers may be glycerol, acrylates, glycerin, glyceryl monostearate (GMS), sorbitol, or mixtures thereof. Based on the total weight of the biodegradable resin composition, the plasticizer may be included in the following amounts: 0.1 wt% to 15 wt%, 0.1 wt% to 14 wt%, 0.1 wt% to 13 wt%, 0.1 wt% to 12 wt%, 0.1 wt% to 11 wt%, 0.1 wt% to 10 wt%, 0.1 wt% to 9 wt%, 0.1 wt% to 8 wt%, 0.1 wt% to 7 wt%, 0.1 wt% to 6 wt%, or 0.1 wt% to 5 wt%. When these ranges are met, molded articles made from biodegradable resin compositions may have improved elongation and tear strength.

[0109] Biodegradable resin compositions may include antioxidants. Antioxidants may include one or more selected from the group consisting of: phosphorus-based antioxidants, phenol-based antioxidants, and pentaerythritol-based antioxidants.

[0110] Phosphorus-based antioxidants may include one or more selected from the group consisting of: triesters of phosphorous phosphite such as triphenyl phosphite, trinonylphenyl phosphite and tris(2,4-di-tert-butylphenyl) phosphite, diesters, monoesters, trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, triphenyl phosphate, tricresyl phosphate, tri(nonylphenyl) phosphate and 2-ethylphenyl diphenyl phosphate.

[0111] Phenolic antioxidants may include one or more of the following groups: α-tocopherol, butylated hydroxytoluene, myrosinol, vitamin E, n-octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 2-tert-butyl-6-(3'-tert-butyl-5'-methyl-2'-hydroxybenzyl)-4-methylphenyl acrylate, 2,6-di-tert-butyl-4-(N,N-dimethylaminomethyl)phenol, and diethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate. Ester, 2,2-bis(((3-(3,5-di-tert-butyl-4-hydroxyphenyl)propoxy)methyl)propane-1,3-diylbis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), pentaerythritol tetra(3,5-di-tert-butyl-4-hydroxyhydrocinnamate), pentaerythritol tetra[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and tetra[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane.

[0112] Antioxidants may further include one or more selected from the group consisting of: BHT, ascorbic acid, catechin, quercetin, dodecyl gallate, TBHQ, Ralox, Irganox 1135, Irganox 1076, nordihydroguaiac acid, epicatechin gallate, epigallocatechin gallate, epigallocatechin gallate, propyl gallate, 2,3,5-trihydroxybutyroxene, butylated hydroxyanisole, 4-hydroxymethyl-2,6-di-tert-butylphenol, α-tocopherol, resveratrol, rutin, astaxanthin, lycopene, beta-carotene, and melatonin.

[0113] Based on the total weight of the biodegradable resin composition, the antioxidant content may be 5 wt% or less, 4 wt% or less, 3 wt% or less, 2 wt% or less, 1.5 wt% or less, 1 wt% or less, 0.5 wt% or less, 0.3 wt% or less, 0 to 5 wt%, 0.01 to 4 wt%, 0.1 to 3 wt%, 1 to 3 wt%, 1 to 2 wt%, 0.01 to 0.3 wt%, 0.05 to 0.3 wt%, 0.15 to 0.3 wt%, or 0.2 to 0.3 wt%.

[0114] Antioxidants may include both phosphorus-based and phenolic antioxidants. When the antioxidant includes both phosphorus-based and phenolic antioxidants, the weight ratio of the phosphorus-based antioxidant to the phenolic antioxidant may be 1:10 to 10:1, 1:5 to 5:1, 1:1 to 5:1, 2:1 to 4:1, 2.5:1 to 3.5:1, 1:5 to 1:1, 1:2 to 1:4, or 1:2.5 to 1:3.5. When these ranges are met, the oxidation of the biodegradable resin composition can be delayed over a variety of temperature ranges.

[0115] Biodegradable resin compositions may include heat stabilizers.

[0116] The heat stabilizer may be a phosphorus heat stabilizer. The heat stabilizer may include one or more selected from the group consisting of: amine-based high-temperature heat stabilizers (e.g., tetraethylenepentamine), triethyl phosphonoacetate, phosphoric acid, phosphorous acid, polyphosphoric acid, trimethyl phosphate, triethyl phosphate, trimethylphosphine, and triphenylphosphine. The heat stabilizer may be an antioxidant with antioxidant properties. Based on the total weight of the biodegradable resin, the amount of heat stabilizer that may be included may be 3,000 ppm or less, 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.

[0117] Biodegradable resin compositions may include lubricants.

[0118] Lubricants may include one or more selected from the group consisting of: fatty acid-based lubricants such as stearic acid; fatty alcohol-based lubricants; aliphatic amide-based lubricants such as stearamide; aliphatic ester-based lubricants such as n-butyl stearate, methyl hydroxystearate, polyol fatty acid esters, saturated fatty acid esters, and ester waxes; and fatty acid metal soap-based lubricants. In particular, the lubricant may be a stearic acid-based lubricant, and may include one or more selected from the group consisting of calcium stearate, zinc stearate, barium stearate, magnesium stearate, glyceryl stearate, and butyl stearate. Stearic acid-based lubricants can reduce the heat generated by friction during the mixing, melting, and processing of raw materials, and have excellent dispersing and lubricating effects on biodegradable polyester resins compared to their price, thereby improving production efficiency.

[0119] Based on the total weight of the biodegradable resin composition, the lubricant content can be 5 wt% or less, 4 wt% or less, 3 wt% or less, 2 wt% or less, 1 wt% or less, less than 1 wt%, 0.9 wt% or less, 0.8 wt% or less, 0.7 wt% or less, 0.5 wt% or less, 0.3 wt% or less, or 0.1 wt% or less. Meeting this range can improve production efficiency without degrading the physical properties of the biodegradable resin composition.

[0120] Biodegradable resin compositions may include flame retardants. Flame retardants may include one or more selected from the group consisting of halogen-based flame retardants, phosphorus-based flame retardants, and non-phosphorus halogen-based flame retardants such as metal hydrates.

[0121] Halogen-based flame retardants may include one or more selected from the group consisting of: halogenated bisphenol compounds such as halogenated bisphenylalkanes, halogenated bisphenyl ethers, halogenated bisphenyl sulfides and halogenated bisphenyl sulfides; and bisphenol-bis(alkyl ether) compounds such as bisphenol A bromide, bisphenol S bromide, bisphenol A chloride and bisphenol S chloride.

[0122] Phosphorus-based flame retardants may include one or more selected from the group consisting of: aluminum tris(diethylphosphonic acid), bisphenol A bis(diphenyl phosphate), triarylisopropyl phosphate, toluene di-2,6-dimethyl phosphate and aromatic condensed phosphates.

[0123] Metal hydrates may include aluminum trihydrate, magnesium dihydrate, or combinations thereof.

[0124] Flame retardant additives used to improve flame retardant effects may include one or more selected from the group consisting of antimony oxides such as antimony trioxide and antimony pentoxide, zinc oxide, iron oxide, aluminum oxide, molybdenum oxide, titanium oxide, calcium oxide, and magnesium oxide.

[0125] Biodegradable resin compositions may include foaming agents. The foaming agent may be mixed with the molten biodegradable resin composition or injected under pressure. The foaming agent may be a phase change from solid to gas or from liquid to gas, or the gas itself, and is used to control the foaming ratio (foaming density) of the foam board.

[0126] Foaming agents may include one or more selected from the group consisting of aliphatic hydrocarbons, alicyclic hydrocarbons, halogenated hydrocarbons, inorganic gases, and water.

[0127] Biodegradable resin compositions may include dispersants. Dispersants can improve the dispersibility of solvents and solutes. Dispersants may include one or more selected from the group consisting of aliphatic polyesters, polylactic acid, polyglycolic acid, polycaprolactone, and polyhydroxyalkanoates.

[0128] Based on the total weight of the biodegradable resin composition, the amount of dispersant that may be included may be 1 to 20 wt%, 1 to 15 wt%, 1 to 13 wt%, 1 to 11 wt%, 2 to 10 wt%, 5 to 15 wt%, 7 to 12 wt%, 2 to 8 wt%, 5 to 8 wt%, or 2 to 5 wt%.

[0129] Biodegradable resin compositions may include chain extenders. Chain extenders may include one or more selected from the group consisting of aromatic diisocyanates, aliphatic diisocyanates, isocyanurates, bisoxazoline, carboxylic anhydrides, and epoxides.

[0130] Aromatic diisocyanates may include one or more selected from the group consisting of: toluene 2,4-diisocyanate, toluene 2,6-diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, naphthalene 1,5-diisocyanate, and phenylenediamine diisocyanate.

[0131] Aliphatic diisocyanates may include one or more selected from the group consisting of 1,6-hexamethylene diisocyanate, isophorone diisocyanate and methylene bis(4-isocyanate cyclohexane).

[0132] Isocyanurates may include isophorone diisocyanate or methylene bis(4-isocyanate cyclohexane).

[0133] Bisoxazoline may include one or more selected from the group consisting of 2,2'-bis(2-oxazoline), bis(2-oxazolinyl)methane, 1,2-bis(2-oxazolinyl)ethane, 1,3-bis(2-oxazolinyl)propane and 1,4-bis(2-oxazolinyl)butane.

[0134] Epoxides refer to epoxy-containing copolymers based on at least one of styrene, acrylate and / or methacrylate, and preferably copolymers having a glycidyl methacrylate content of more than 20, 30 or 50 wt%.

[0135] Based on the total weight of the biodegradable resin composition, the amount of chain extender that may be included is 1.5 wt% or less, 1.4 wt% or less, 1.3 wt% or less, 1.2 wt% or less, 1.1 wt% or less, 1 wt% or less, 0.9 wt% or less, 0.8 wt% or less, 0.7 wt% or less, 0.6 wt% or less, 0.5 wt% or less, 0.4 wt% or less, 0.3 wt% or less, 0 wt% to 1.5 wt%, 0.01 wt% to 1.5 wt%, 0.1 wt% to 1.5 wt%, 0.1 wt% to 1.0 wt%, 0.1 wt% to 0.9 wt%, 0.1 wt% to 0.8 wt%, 0.1 wt% to 0.7 wt%, 0.1 wt% to 0.6 wt%, or 0.1 wt%. wt% to 0.5 wt%.

[0136] Biodegradable resin compositions may include hydrolysis inhibitors. A higher weight-average molecular weight (Mw) of the hydrolysis inhibitor results in lower volatility and improved hydrolysis resistance. Conversely, a lower weight-average molecular weight (Mw) of the hydrolysis inhibitor improves compatibility with the biodegradable resin.

[0137] Two hydrolysis inhibitors with different weight-average molecular weights (Mw) can be used as hydrolysis inhibitors. One Mw with a weight-average molecular weight (Mw) of 10,000 g / mol or less, 9,000 g / mol or less, 8,000 g / mol or less, 7,000 g / mol or less, 6,000 g / mol or less, or 5,000 g / mol or less can be used to increase compatibility with biodegradable resins. A Mw with a weight-average molecular weight of 10,000 g / mol or greater, 20,000 g / mol or greater, 30,000 g / mol or greater, 40,000 g / mol or greater, or 50,000 g / mol or greater can be used to improve low volatility and hydrolysis resistance. The weight-average molecular weight can be used as a relative value to a standard PS (standard polystyrene) sample and measured by GPC using THF as the eluent. When this range is met, the mechanical properties and hydrolysis resistance of biodegradable resin compositions can be improved.

[0138] Hydrolysis inhibitors may include carbodiimide compounds. These compounds can react with water and acid to transform into a urea structure, thereby reducing the reactivity between water, acid, and ester groups included in the biodegradable resin, thus reducing the hydrolysis of the biodegradable resin by water and acid. In summary, the hydrolysis resistance of biodegradable resin compositions can be improved.

[0139] Carbodiimine compounds may include compounds represented by the following formula 4: [Formula 4]

[0140] In Equation 4, n is an integer from 1 to 20.

[0141] Carbodiimide compounds may be one or more selected from the group consisting of: N,N'-di-o-tolylcarbodiimide, N,N'-diphenylcarbodiimide, N,N'-dioctyldecylcarbodiimide, N,N'-di-2,6-diketophenylcarbodiimide, N-tolyl-N'-cyclohexylcarbodiimide, N,N'-di-2,6-diisopropylphenylcarbodiimide, N,N'-di-2,6-di-tert-butylphenylcarbodiimide, N-tolyl-N'-phenylcarbodiimide, N,N'-di-p-nitrophenylcarbodiimide, N,N'-di- Homopolymers of p-aminophenylcarbodiimide, N,N'-di-p-hydroxyphenylcarbodiimide, N,N'-dicyclohexylcarbodiimide, N,N'-di-p-tolylcarbodiimide, p-phenylene-bis-di-o-tolylcarbodiimide, p-phenylene-bis-dicyclohexylcarbodiimide, hexamethylene-bis-dicyclohexylcarbodiimide, ethylene-bis-diphenylcarbodiimide, and phenyl-2,4-diisocyanate-1,3,5-tris(1-methylethyl), as well as copolymers of 2,4-diisocyanate-1,3,5-tris(1-methylethyl) and 2,6-diisopropyl diisocyanate.

[0142] The weight-average molecular weight (Mw) of the carbodiimine compound can be from 500 g / mol to 100,000 g / mol, 600 g / mol to 100,000 g / mol, 700 g / mol to 100,000 g / mol, 800 g / mol to 90,000 g / mol, 900 g / mol to 80,000 g / mol, 1,000 g / mol to 70,000 g / mol, 1,000 g / mol to 60,000 g / mol, or 1,000 g / mol to 50,000 g / mol.

[0143] The NCN group content in the carbodiimide compound can be 1 wt% to 20 wt%, 1 wt% to 19 wt%, 1 wt% to 18 wt%, 1 wt% to 17 wt%, 1 wt% to 16 wt%, 1 wt% to 15 wt%, 2 wt% to 15 wt%, 3 wt% to 15 wt%, 4 wt% to 15 wt%, 5 wt% to 15 wt%, or 6 wt% to 15 wt%. The NCN group content in the carbodiimide compound can be measured by titration with oxalic acid. When this range is met, the hydrolysis resistance of the biodegradable resin composition can be improved without compromising its compatibility with the biodegradable resin.

[0144] Based on the total weight of the biodegradable resin composition, the content of the hydrolysis inhibitor can be 0.1 wt% to 5.0 wt%, 0.1 wt% to 4.0 wt%, 0.1 wt% to 3.0 wt%, 0.1 wt% to 2.0 wt%, 0.1 wt% to 1.5 wt%, or 0.1 wt% to 1.0 wt%. When this range is met, the hydrolysis resistance and odor reduction effect of the biodegradable resin composition can be further improved.

[0145] Based on the total weight of the biodegradable resin, the biodegradable resin composition may include compounds comprising urea groups in the following amounts: 0.01 wt% to 10.00 wt%, 0.01 wt% to 9.00 wt%, 0.01 wt% to 8.00 wt%, 0.01 wt% to 7.00 wt%, 0.01 wt% to 6.00 wt%, 0.01 wt% to 5.00 wt%, 0.01 wt% to 4.00 wt%, or 0.01 wt% to 3.00 wt%. When this range is met, the proportion of ester groups in the biodegradable resin that can react with water or acid is reduced, thus improving hydrophilicity.

[0146] Biodegradable resin samples made from biodegradable resin compositions have a molding shrinkage rate of 1.0% or less, as measured by the following measurement method 1: [Measurement Method 1] 1) Place the biodegradable resin composition between a pair of molds with dimensions of 60 mm in the transverse direction and 60 mm in the longitudinal direction, and then manufacture a biodegradable resin sample with an average thickness of 2 mm at 180°C under a pressure of 20 MPa. 2) Remove the biodegradable resin sample from the mold and calculate the transverse shrinkage rate and longitudinal shrinkage rate of the biodegradable resin sample after 24 hours. 3) The molding shrinkage rate of biodegradable resin samples is calculated according to the following equation 1: [Equation 1] Molding shrinkage rate (%) of biodegradable resin sample = (transverse shrinkage rate + longitudinal shrinkage rate) / 2 In Equation 1, the lateral shrinkage rate is calculated by Equation 2, and the longitudinal shrinkage rate is calculated by Equation 3. [Equation 2] Transverse shrinkage rate (%) = (Transverse length of the biodegradable resin sample after 24 hours (mm) / 60 mm) × 100 [Equation 3] Longitudinal shrinkage rate (%) = (Longitudinal length of the biodegradable resin sample after 24 hours (mm) / 60 mm) × 100

[0147] In the context of biodegradable resin samples after 24 hours, "24 hours" may be an indicator of the general cooling time used in injection molding when biodegradable resin compositions are injection molded into biodegradable molded articles.

[0148] The "molding shrinkage" of a biodegradable resin sample can be used as an indicator to measure the balance between dimensional stability and physical properties that have a trade-off with dimensional stability when a biodegradable resin composition is made into a biodegradable molded product by injection molding.

[0149] Injection molding is a method of melting a biodegradable resin composition, injecting the molten biodegradable resin composition into a mold, and then cooling it for a certain period of time to form a cured biodegradable resin composition. During the melting of the biodegradable resin composition, injection molding may be affected by high temperatures, and processability, mechanical properties, dimensional stability, etc., may change depending on the characteristics of the biodegradable resin composition during the cooling process.

[0150] The biodegradable resin composition according to the present invention comprises a first biodegradable resin having a glass transition temperature (Tg) of -15 ºC or lower, and biodegradable molded articles made from this biodegradable resin composition can be environmentally friendly and can exhibit excellent tensile strength and elongation. However, due to the low glass transition temperature of the first biodegradable resin, the polymer chain flow may change significantly during cooling, resulting in poor dimensional stability due to high shrinkage during injection molding, thus limiting its application in products.

[0151] Therefore, since the biodegradable resin composition according to the present invention comprises a first biodegradable resin having a glass transition temperature (Tg) of -15 ºC or lower and an inorganic filler, and the molding shrinkage rate of the biodegradable resin sample measured according to measurement method 1 is adjusted to 1.0% or lower, volume change can be minimized when the biodegradable resin composition is made into a biodegradable molded article by injection molding, thereby improving dimensional stability at room temperature and high temperature. Furthermore, flexural strength, flexural modulus, and specific gravity are improved, and mechanical properties are correspondingly improved, making it more suitable for cosmetic container products requiring anti-corrosion functions, durability, etc.

[0152] The molding shrinkage of the biodegradable resin sample can be 1.0% or less, 0.5% or less, 0.45% or less, 0.4% or less, 0.3% or less, 0.25% or less, or 0.2% or less.

[0153] When this range is met, dimensional stability can be improved without reducing machinability and mechanical properties.

[0154] According to measurement method 2 below, the first coefficient of thermal expansion of the biodegradable resin sample made from the biodegradable resin composition can be 75. Up to 290 : [Measurement Method 2] 1) Cut the biodegradable resin sample into 20 mm horizontally × 4 mm vertically × 0.7 mm thick to prepare a biodegradable resin sample. 2) Using a thermomechanical analyzer, the first coefficient of thermal expansion of the biodegradable resin sample was measured in the range of 10°C to 40°C while heating from 0°C to 100°C at a rate of 5°C / min.

[0155] According to measurement method 2, the second coefficient of thermal expansion of the biodegradable resin sample made from the biodegradable resin composition can be in the range of 80 ºC to 100 ºC. Up to 1,000 .

[0156] The first coefficient of thermal expansion can be an indicator of the dimensional stability of a biodegradable resin composition at room temperature. The second coefficient of thermal expansion can be an indicator of the dimensional stability of a biodegradable resin composition at high temperatures.

[0157] The first coefficient of thermal expansion can be 75. Up to 290 90 Up to 290 108 Up to 250 Or 108 Up to 214 When this range is met, dimensional stability can be improved during the injection molding process, particularly during the cooling of the biodegradable resin composition. The second biodegradable resin described above can further improve dimensional stability at room temperature.

[0158] The second coefficient of thermal expansion can be 100. Up to 1,000 200 Up to 1,000 300 Up to 1,000 500 Up to 900 Or 569 Up to 871 When this range is met, dimensional stability can be improved during the injection molding process, specifically during the melting of the biodegradable resin composition. Dimensional stability at high temperatures can be improved by combining a first biodegradable resin and a second biodegradable resin.

[0159] According to the measurement method 3 below, the specific gravity of biodegradable resin particles made from biodegradable resin compositions can be from 1.30 to 2.00. [Measurement Method 3] 1) A biodegradable resin composition is extruded at 175 ºC and then cooled at 5 ºC to produce biodegradable resin particles. 2) Measure the specific gravity of biodegradable resin particles at 23 °C according to ASTM D792 standard.

[0160] The specific gravity can be 1.30 to 1.90, 1.30 to 1.80, 1.30 to 1.70, 1.40 to 1.70, 1.50 to 1.70, or 1.59 to 1.63. When this range is met, it is more suitable for cosmetic container products requiring anti-corrosion and durability. The specific gravity can be adjusted according to the content of the inorganic filler mentioned above.

[0161] The biodegradable molded articles according to the present invention can be manufactured from the above-described biodegradable resin composition.

[0162] Biodegradable molded articles comprise a biodegradable resin composition comprising a first biodegradable resin having a glass transition temperature (Tg) of -15 ºC or lower and an inorganic filler, and wherein the molding shrinkage of the biodegradable resin sample, measured according to the following measurement method 1, is 1.0% or lower: [Measurement Method 1] 1) Place the biodegradable resin composition between a pair of molds with dimensions of 60 mm in the transverse direction and 60 mm in the longitudinal direction, and then manufacture a biodegradable resin sample with an average thickness of 2 mm at 180°C under a pressure of 20 MPa. 2) Remove the biodegradable resin sample from the mold and calculate the transverse shrinkage rate and longitudinal shrinkage rate of the biodegradable resin sample after 24 hours. 3) The molding shrinkage rate of biodegradable resin samples is calculated according to the following equation 1: [Equation 1] Molding shrinkage rate (%) of biodegradable resin sample = (transverse shrinkage rate + longitudinal shrinkage rate) / 2 In Equation 1, the lateral shrinkage rate is calculated by Equation 2, and the longitudinal shrinkage rate is calculated by Equation 3. [Equation 2] Transverse shrinkage rate (%) = (Transverse length of the biodegradable resin sample after 24 hours (mm) / 60 mm) × 100 [Equation 3] Longitudinal shrinkage rate (%) = (Longitudinal length of the biodegradable resin sample after 24 hours (mm) / 60 mm) × 100

[0163] The first biodegradable resin, inorganic filler, molding shrinkage, and biodegradable resin composition may be the same as the first biodegradable resin, inorganic filler, molding shrinkage, and biodegradable resin composition described above.

[0164] Biodegradable molded products can be nonwoven fabrics, vacuum-formed sheets, blow-molded products, or injection-molded products.

[0165] Biodegradable molded products can be biodegradable membranes. The thickness of a biodegradable membrane can be 5. Up to 500 5 Up to 400 5 Up to 350 10 Up to 350 15 Up to 350 20 Up to 350 25 Up to 300 30 Up to 300 35 Up to 300 Or 40 Up to 300 The tensile strength of biodegradable membranes can be 5 MPa or higher, 7 MPa or higher, 9 MPa or higher, 10 MPa or higher, 11 MPa or higher, 100 MPa or lower, 95 MPa or lower, 90 MPa or lower, or 5 MPa or higher to 100 MPa or lower. When this range is met, the membrane is not easily torn, has excellent mechanical properties, and decomposes readily when discarding biodegradable molded articles containing the membrane.

[0166] Biodegradable membranes can have elongation of 85% or higher, 90% or higher, 95% or higher, 1,000% or less, 950% or less, 900% or less, or 850% or less. The elasticity of biodegradable molded products is guaranteed, thus allowing them to withstand certain loads.

[0167] Biodegradable molded articles can be biodegradable sheets. The thickness of biodegradable sheets can be 5 mm. Up to 1,000 10 Up to 1,000 15 Up to 1,000 20 Up to 1,000 25 Up to 1,000 30 Up to 1,000 35 Up to 1,000 or 40 Up to 1,000 The tensile strength of biodegradable sheets can be 5 MPa or higher, 6 MPa or higher, 9 MPa or higher, 10 MPa or higher, 11 MPa or higher, 12 MPa or higher, 55 MPa or lower, 54 MPa or lower, 53 MPa or lower, 52 MPa or lower, 51 MPa or lower, or 50 MPa or lower. The tear strength of biodegradable sheets can be 100 N / cm or higher, 110 N / cm or higher, 120 N / cm or higher, 130 N / cm or higher, 140 N / cm or higher, 150 N / cm or higher, 700 N / cm or lower, 650 N / cm or lower, 600 N / cm or lower, 550 N / cm or lower, or 500 N / cm or lower. When these ranges are met, the sheets are not easily torn and readily decompose when discarding biodegradable molded articles containing the film.

[0168] Biodegradable sheets can have elongation of 10% or higher, 15% or higher, 20% or higher, 50% or less, 70% or higher, 700% or less, 650% or less, 550% or less, 500% or less, or 450% or less. When these ranges are met, the elasticity of biodegradable molded articles can be guaranteed, thus enabling them to withstand certain loads.

[0169] Preferably, the biodegradable molded article can be an injection-molded article, and the injection-molded article can be a cosmetic container. This biodegradable molded article has a high specific gravity, making it more suitable for cosmetic container products requiring preservation functions and durability.

[0170] A method for manufacturing a biodegradable molded article according to the present invention may include: a step of preparing a prepolymer by esterifying a diol component and a dicarboxylic acid component; a step of preparing a first biodegradable resin having a glass transition temperature (Tg) of -15 ºC or lower by polycondensation of the prepolymer; a step of preparing a biodegradable resin composition by mixing the first biodegradable resin with an inorganic filler; and a step of injection molding the biodegradable resin composition.

[0171] The preparation method may include the step of preparing a prepolymer by esterifying a diol component and a dicarboxylic acid component.

[0172] The diol and dicarboxylic acid components can be the same as those in the biodegradable resin composition described above. In this step, the prepolymer can be prepared by a one-step esterification reaction of the diol component, the dicarboxylic acid component, and optionally a composition containing nanocellulose, or by a two-step esterification reaction consisting of a first esterification reaction and a second esterification reaction.

[0173] A two-step esterification reaction may include a first esterification reaction involving a diol component and a dicarboxylic acid component, and a second esterification reaction involving adding the diol component and the dicarboxylic acid component to the product of the first step.

[0174] When the biodegradable resin includes nanocellulose, the binding strength of the nanocellulose can be improved by adding nanocellulose in the second esterification reaction step. Furthermore, the binding force of the nanocellulose can be further improved by adding water-dispersible nanocellulose in the second esterification reaction step.

[0175] Nanocellulose can be added at temperatures of 100 °C to 160 °C, 110 °C to 140 °C, or 110 °C to 150 °C. When these ranges are met, solvent resistance can be improved.

[0176] The addition rate of nanocellulose can be 2 kg / min to 10 kg / min, 2.5 kg / min to 9.5 kg / min, or 3 kg / min to 8 kg / min. When this range is met, the efficiency of the production process can be improved without causing the nanocellulose to re-agglomerate.

[0177] In this step, titanium-based catalysts, germanium-based catalysts, antimony-based catalysts, additives, and stabilizers may be added prior to the esterification reaction. The esterification reaction can be carried out at temperatures of 250 °C or lower, 240 °C or lower, 235 °C or lower, 180 °C to 250 °C, 185 °C to 240 °C, or 180 °C to 240 °C for 0.5 to 5 hours, 0.5 to 4.5 hours, 0.5 to 3.5 hours, or 1 to 3 hours, respectively. The esterification reaction can be carried out at atmospheric pressure until, theoretically, the byproducts of water and methanol reach 90%.

[0178] The prepolymer can have a number-average molecular weight of 500 g / mol to 10,000 g / mol, 500 g / mol to 8,500 g / mol, 500 g / mol to 7,000 g / mol, 1,000 g / mol to 6,000 g / mol, or 2,500 g / mol to 5,500 g / mol. The number-average molecular weight can be measured by gel permeation chromatography (GPC). When this range is met, the molecular weight of the prepolymer can be effectively increased during the polycondensation reaction, thereby improving strength properties.

[0179] The manufacturing method may include the step of preparing a first biodegradable resin by polycondensing a prepolymer.

[0180] Polycondensation can be carried out at temperatures of 180 °C to 280 °C, 190 °C to 270 °C, 210 °C to 260 °C, or 230 °C to 255 °C. Polycondensation can be carried out at pressures of 1.0 Torr or lower, 0.9 Torr or lower, 0.7 Torr or lower, 0.2 Torr to 1.0 Torr, 0.3 Torr to 0.9 Torr, or 0.5 Torr to 0.9 Torr. Polycondensation can be carried out for 1 hour to 6 hours, 1.5 hours to 5.5 hours, 2 hours to 5 hours, or 3.5 hours to 4.5 hours.

[0181] The first biodegradable resin prepared in this step may have an intrinsic viscosity of 0.05 to 10 dL / gr. Measured using a rheological dynamic spectroscopy (RDS) at 100 s⁻¹, the melt viscosity of the first biodegradable resin may be 1,000 to 30,000 poise. The number-average molecular weight (Mn) of the first biodegradable resin may be 40,000 g / mol or higher, 43,000 g / mol or higher, 45,000 g / mol or higher, or 40,000 g / mol to 70,000 g / mol. The weight-average molecular weight (MW) of the first biodegradable resin may be 60,000 g / mol or higher, 65,000 g / mol or higher, 75,000 g / mol or higher, 80,000 g / mol or higher, or 85,000 g / mol to 100,000 g / mol. The first biodegradable resin may have a polydispersity index (PDI) of 1.2 to 2.0, 1.5 to 1.9, or 1.6 to 1.8. When the number-average molecular weight, weight-average molecular weight, or polydispersity index of the first biodegradable resin meets this range, strength and processability can be further improved. The first biodegradable resin may have an acid value of 1.8 mgKOH / g or less, 1.5 mgKOH / g or less, 1.3 mgKOH / g or less, or 1.25 mgKOH / g or less. When this range is met, solvent resistance can be improved.

[0182] The preparation method may include the step of preparing a biodegradable resin composition by mixing a first biodegradable resin with an inorganic filler.

[0183] The preparation method may include the step of mixing a first biodegradable resin, an inorganic filler, and a second biodegradable resin different from the first biodegradable resin to prepare a biodegradable resin composition.

[0184] The second biodegradable resin can be the same as the second biodegradable resin described above.

[0185] The mixing process can be appropriately configured depending on the molding method. For example, the first and second biodegradable resins and inorganic fillers can be melt-kneaded before being fed into the molding machine via a hopper. Alternatively, the melt-kneading and molding of the first and second biodegradable resins and inorganic fillers can be performed simultaneously. It is desirable to use high shear stress for kneading to ensure that the inorganic filler is uniformly distributed in the first and second biodegradable resins. In particular, it is preferable to use a kneading reactor, an extrusion molding machine equipped with a single screw, or a twin-screw kneader for kneading. If necessary, one or more of the aforementioned plasticizers and additives can be added in the steps.

[0186] This step may include a mixing step consisting of one or more stages. A single-stage mixing step may be a single mixing step for preparing a biodegradable resin composition comprising an amount of inorganic filler of 60 to 80 wt%, 61 to 80 wt%, 62 to 80 wt%, 63 to 80 wt%, 64 to 80 wt%, 65 to 80 wt%, 60 to 75 wt%, 61 to 75 wt%, 62 to 75 wt%, 63 to 75 wt%, 64 to 75 wt%, 65 to 75 wt%, or 65 to 72 wt% based on the total weight of the biodegradable resin composition. The two-stage mixing step may include a first mixing step for preparing a biodegradable resin composition comprising an inorganic filler in an amount of 60 to 80 wt%, 61 to 80 wt%, 62 to 80 wt%, 63 to 80 wt%, 64 to 80 wt%, 65 to 80 wt%, 60 to 75 wt%, 61 to 75 wt%, 62 to 75 wt%, 63 to 75 wt%, 64 to 75 wt%, 65 to 75 wt%, or 65 to 72 wt% based on the total weight of the biodegradable resin composition, and a second mixing step for preparing a biodegradable resin composition comprising an inorganic filler in an amount of 30 to 85 wt%, 30 to 80 wt%, 30 to 75 wt%, 30 to 70 wt%, 35 to 85 wt%, 35 to 80 wt%, 35 to 75 wt%, or 35 to 70 wt% based on the total weight of the biodegradable resin composition. wt%, 40 to 85 wt%, 40 to 80 wt%, 40 to 75 wt%, 40 to 70 wt%, 45 to 85 wt%, 45 to 80 wt%, 45 to 75 wt%, 45 to 70 wt%, 50 to 85 wt%, 50 to 80 wt%, 50 to 75 wt% or 50 to 70 wt%.

[0187] The mixing step, consisting of two or more stages, can be a series continuous process. The mixing step can be carried out at temperatures of 150 to 190°C, 150 to 180°C, or 160 to 180°C. Meeting these ranges can reduce the increase in torque during the mixing step and can reduce the thermal decomposition of the mixed biodegradable resin composition.

[0188] The preparation method may include step (d) of preparing particles of a biodegradable resin composition.

[0189] In this step, a biodegradable resin composition is fed into an extruder equipped with a single screw or a twin screw, extruded at a temperature of 150 °C to 180 °C, cut with a hot pelletizer, and then cooled at temperatures of 30 °C or lower, 25 °C or lower, 5 to 50 °C, 10 to 30 °C, 15 to 25 °C, or 20 to 25 °C to obtain pellets. In the cutting step, no particular limitation may be placed on the use of pelletizers used in the art, and no particular limitation may be placed on the shape of the produced pellets.

[0190] The preparation method may include the step of injection molding a biodegradable resin composition.

[0191] The biodegradable resin composition may be a granular biodegradable resin composition.

[0192] In this step, an injection molding machine can be used to form injection molded articles from a granulated biodegradable resin composition at injection molding barrel temperatures of 150 ºC to 250 ºC, 160 ºC to 250 ºC, 160 ºC to 240 ºC, or 160 ºC to 230 ºC.

[0193] Injection molding can be performed through injection molding methods such as injection compression molding, injection stamping, gas-assisted injection molding, foam molding, insert molding, in-mold coating molding, insulating molding, rapid heating and cooling molding, two-color molding, sandwich molding, and ultra-high-speed injection molding.

[0194] The invention will be described in more detail below based on embodiments and comparative examples. However, the embodiments and comparative examples are provided to explain the invention in more detail, and the invention is not limited to the embodiments and comparative examples.

[0195] [Preparation Example] []

[0196] [Examples of Nanocellulose Preparation]

[0197] The subtlety it possesses is approximately 1 To approximately 50 Cellulose nanocrystals (NVC-100, manufacturer: Celluforce) in dry powder form were dispersed in water at 1 wt% and then sonicated for 2 minutes using a tip-type ultrasonic disperser at an output of 20,000 J / s to prepare nanocellulose.

[0198] [Preparation Example] [1]

[0199] - Step 1: Obtaining the prepolymer

[0200] 1,4-Butanediol (1,4-BDO) and terephthalic acid (TPA) were fed into a 5 kg esterification reactor equipped with a nitrogen inlet and a stirrer to prepare a slurry. Here, the molar ratio of 1,4-butanediol (1,4-BDO) to terephthalic acid (TPA) was 1.4:1, and the D50 of terephthalic acid (TPA) was 130. .

[0201] The slurry was fed into the reactor via a feed line, and 250 ppm of tetrabutyl titanate (Dupont, produced by Tyzor TnBT) was added as a titanium-based catalyst. The slurry was then heated to 210 °C and subjected to esterification until approximately 90% or more of the water (byproduct) was removed to prepare the first prepolymer.

[0202] 53 mol% of 1,4-butanediol (1,4-BDO) based on the total moles of the diol component was added to the product of the first esterification reaction, along with 53 mol% of adipic acid (AA) based on the total moles of the dicarboxylic acid component, and 200 ppm of tetrabutyl titanate (Dupont, produced by Tyzor TnBT), a titanium-based catalyst, was fed into the product. Additionally, 100 ppm of nanocellulose according to the preparation example was added to the product of the first esterification reaction. Next, a second esterification reaction was carried out at 220ºC and atmospheric pressure for approximately 2 hours and 30 minutes until 95% of the byproduct water was removed, thus preparing a second prepolymer with a number average molecular weight of 5,500 g / mol.

[0203] Step 2: Condensation reaction

[0204] The second prepolymer was transferred to a 5 kg polycondensation reactor. 150 ppm of a titanium-based catalyst, tetrabutyl titanate (Dupont, manufactured by Tyzor TnBT), and 500 ppm of triethyl phosphate stabilizer were added based on the total weight of the second prepolymer, and the mixture was then stabilized for approximately 10 minutes.

[0205] Next, after heating to 240 ºC, a polycondensation reaction was carried out at 0.5 Torr for 2 hours to produce PBAT resin with a number average molecular weight of about 42,000 g / mol and a glass transition temperature (Tg) of -30 ºC.

[0206] [Preparation Example] [2]

[0207] PBAT resin with a number average molecular weight of about 25,000 g / mol and a glass transition temperature (Tg) of -35 ºC was prepared in the same manner as in Preparation Example 1, except that 120 ppm nanocellulose was added instead of 100 ppm nanocellulose in Preparation Example 1, and the polycondensation reaction was carried out for 1 hour and 30 minutes instead of 2 hours in Preparation Example 1.

[0208] [Example] []

[0209] - First biodegradable resin #1: Preparation example 1 - First biodegradable resin #2: Preparation example 2 - First biodegradable resin #3: KINGFA PBAT, Tg -30 ºC - Second biodegradable resin: polylactic acid (poly-D-lactic acid content: approximately 1%, Tg 60 ºC) - Calcium Carbonate #1: Omya Company - Calcium carbonate #2: Heavy calcium carbonate surface-treated with stearic acid (average particle size (D50) approximately 3 mm). ) - Chain extender: BASF Company Joncryl - Lubricant #1: Calcium stearate - Lubricant #2: Stearyl stearate - Antioxidant #1: Phenolic antioxidant, ADEKA KOREA Company AO-60 - Antioxidant #2: Phosphorus Antioxidant, ADEKA KOREA Company 2112

[0210] [Example] [1]

[0211] In a kneader reactor, a first biodegradable resin #1: calcium carbonate #1: chain extender: antioxidant #1: antioxidant #2 are mixed in a weight ratio of 52:47:0.2:0.4:0.4 to prepare a biodegradable resin composition.

[0212] [Example] [2] [to] [8] [and comparative examples] [1] [to] [2]

[0213] The biodegradable resin composition was prepared according to the compositions shown in Table 1 below.

[0214] [Table 1] category First biodegradable resin #1 First biodegradable resin #2 The first biodegradable resin #3 The second biodegradable resin Calcium carbonate #1 Calcium carbonate #2 Chain extender Lubricant #1 Lubricant #2 Antioxidant #1 Antioxidant #2 unit wt% Example 1 52 - - - 47 - 0.2 - - 0.4 0.4 Example 2 32 - - 20 47 - - - - 0.5 0.5 Example 3 20 - - 32 47 - - - - 0.5 0.5 Example 4 32 - - 20 - 47 - 0.4 0.4 0.1 0.1 Example 5 20 - - 32 - 47 - 0.4 0.4 0.1 0.1 Example 6 - - 9 50 - 40 - 0.4 0.4 0.1 0.1 Example 7 - - 19 50 - 30 - 0.4 0.4 0.1 0.1 Example 8 - - 39 35 - 25 - 0.4 0.4 0.1 0.1 Comparative Example 1 - 100 - - - - - - - - - Comparative Example 2 - 100 - - - - - - -

[0215] [Experimental Example] []

[0216] Production of Biodegradable Resin Particles

[0217] The biodegradable resin compositions of each of Examples 1 to 8 and Comparative Examples 1 to 2 were kneaded at about 170ºC using a twin-screw extruder, and then cut and cooled to produce granulated biodegradable resin compositions.

[0218] Production of Biodegradable Resin Samples

[0219] Biodegradable resin particles from each of Examples 1 to 8 and Comparative Examples 1 to 2 were placed into a pair of molds having dimensions of 60 mm laterally × 60 mm longitudinally. Then, biodegradable resin samples with an average thickness of 2 mm were produced under conditions of 180 ºC and 20 MPa.

[0220] Production of Biodegradable Resin Samples

[0221] The biodegradable resin sample was cut into pieces with a transverse diameter of 20 mm, a longitudinal diameter of 4 mm, and a thickness of 0.7 mm to produce a biodegradable resin sample.

[0222] [Experimental Example] [1–] [Molding shrinkage] []

[0223] When the biodegradable resin compositions of each of Examples 1 to 8 and Comparative Examples 1 to 2 were made into biodegradable molded articles by injection molding, their volume changes were evaluated. To evaluate shrinkage stability, the biodegradable resin samples were removed from the mold, and the shrinkage rate of the biodegradable resin samples after 24 hours was calculated. In particular, for the biodegradable resin samples manufactured in each of Examples 1 to 8 and Comparative Examples 1 to 2, the transverse shrinkage rate, longitudinal shrinkage rate, and molding shrinkage rate were measured according to the following equations 1 to 3. The results are shown in Table 2 below.

[0224] [Equation 1] Molding shrinkage rate (%) of biodegradable resin sample = (transverse shrinkage rate + longitudinal shrinkage rate) / 2 In Equation 1, the lateral shrinkage rate is calculated by Equation 2, and the longitudinal shrinkage rate is calculated by Equation 3. [Equation 2] Transverse shrinkage rate (%) = (Transverse length of the biodegradable resin sample after 24 hours (mm) / 60 mm) × 100 [Equation 3] Longitudinal shrinkage rate (%) = (Longitudinal length of the biodegradable resin sample after 24 hours (mm) / 60 mm) × 100

[0225] [Experimental Example] [2 –] Coefficient of thermal expansion []

[0226] When the biodegradable resin compositions of Examples 1 to 8 and Comparative Examples 1 to 2 were made into biodegradable molded articles by injection molding process, the dimensional stability at room temperature and at high temperature was evaluated.

[0227] To assess dimensional stability, the first coefficient of thermal expansion was measured for each of the biodegradable resin samples from Examples 1 to 8 and Comparative Examples 1 to 2 in the range of 10 ºC to 40 ºC, and the second coefficient of thermal expansion was measured in the range of 80 ºC to 100 ºC. The results are shown in Table 2 below.

[0228] - Analytical equipment: TMA (Thermomechanical Analysis), TA Company Q400 - Test method: ASTM E831 - Measurement mode: Tension mode - Heating rate: 5 ºC / min - Load: 0.05 N - Atmosphere: N2, Flow rate (50 mL / min) - Measurement temperature range: 0 ºC to 100 ºC

[0229] [Experimental Example] [3–] [proportion] []

[0230] For each of the biodegradable resin particles in Examples 1 to 8 and Comparative Examples 1 to 2, the specific gravity was measured at 23 °C according to ASTM D792. The results are shown in Table 2 below.

[0231] [Experimental Example] [4 -] [Tensile strength and elongation at break] []

[0232] For each of the biodegradable resin compositions in Examples 1 to 8 and Comparative Examples 1 to 2, tensile strength and elongation at break were measured according to ASTM D638. The results are shown in Table 2 below.

[0233] [Experimental Example] [5 –] [Flexural strength and flexural modulus] []

[0234] For each of the biodegradable resin compositions in Examples 1 to 8 and Comparative Examples 1 to 2, flexural strength and flexural modulus were measured according to ASTM D790. The results are shown in Table 2 below.

[0235] [Experimental Example] [6–] Impact strength []

[0236] For each of the biodegradable resin compositions in Examples 1 to 8 and Comparative Examples 1 to 2, tensile strength and elongation at break were measured according to ASTM D256. The results are shown in Table 2 below.

[0237] [Experimental Example] [7–] [Biodegradability] []

[0238] Culture containers, manufactured according to ISO 14855, containing only compost, were prepared. Biodegradable resin samples from each of Examples 1 to 8 and Comparative Examples 1 to 2 were added to the compost at a weight ratio of 6:1 (weight of dry compost: weight of biodegradable resin sample). The compost was then cultured for 180 days at 60ºC, 90% humidity, and 6% or higher oxygen concentration. Carbon dioxide generated in each test container was captured and titrated with an aqueous phenolphthalein solution to measure the amount of carbon dioxide generated. Biodegradability was calculated according to Equation 4 below, and the results are shown in Table 2.

[0239] [Equation 4] Biodegradability (%) = [(CO2 generation in test container) - (CO2 generation in culture medium container)] / (theoretical CO2 generation in test container) × 100

[0240] [Table 2] unit Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Comparative Example 1 Comparative Example 2 lateral shrinkage rate % 0.2 0.2 0.3 0.2 0.3 0.4 0.4 0.5 1.1 0.7 longitudinal shrinkage rate 0.2 0.3 0.3 0.2 0.3 0.4 0.5 0.5 1.2 0.7 Molding shrinkage 0.2 0.25 0.3 0.2 0.3 0.4 0.45 0.5 1.15 0.7 First coefficient of thermal expansion 214 142 108 135 105 72 98 156 297 72.5 Second thermal expansion coefficient 630 569 871 542 830 912 925 952 1,060 13,952 proportion - 1.59 1.63 1.63 1.63 1.63 1.57 1.48 1.49 1.23 1.24 Tensile strength MPa 11 17.6 22.8 18.1 23.4 32.7 34.1 23.3 twenty two 72 Elongation at break % 450 6 4.1 12 6.5 16.2 21.3 25.4 658 3 flexural strength MPa 10.3 twenty three 34.9 twenty four 35.3 49.6 42.1 31.0 7.7 124 Flexural modulus 310 860 1,450 875 1,520 3,040 1,920 1,020 127 3,402 Impact strength kJ / m 2 45 7.1 6.7 9.2 8.8 12.2 14.0 11.0 NB 1) 29 Biodegradability % 90 90 90 90 90 90 90 90 90 80 1) Notebook: Undamaged (No damage)

[0241] As shown in Tables 1 and 2, compared to Comparative Examples 1 to 2, Examples 1 to 8, which comprise biodegradable resins containing diols, aromatic dicarboxylic acids, and aliphatic dicarboxylic acids and inorganic fillers, and have a molding shrinkage rate of 1.0% or less, demonstrated excellent shrinkage and dimensional stability at both room temperature and high temperature. Furthermore, Examples 1 to 8 were shown to have a higher specific gravity than Comparative Examples 1 to 2, making them suitable for products requiring corrosion resistance, durability, etc., and exhibiting excellent flexural strength and flexural modulus. Additionally, Examples 1 to 8 were shown to have superior elongation at break and impact strength compared to Comparative Example 2, resulting in reduced brittleness and improved processability.

Claims

1. A biodegradable resin composition, comprising: The first biodegradable resin has a glass transition temperature of -15ºC or lower. A second biodegradable resin, different from the first biodegradable resin; and an inorganic filler, wherein the first biodegradable resin contains PBAT resin, the second biodegradable resin contains PLA resin with a glass transition temperature (Tg) of 50°C or higher, wherein the inorganic filler contains CaCO3, and the content of the inorganic filler is 40 wt% to 90 wt% based on the total weight of the biodegradable resin composition, wherein the molding shrinkage of the biodegradable resin sample, measured according to the following measurement method 1, is 0.5% or less, and wherein the specific gravity of the biodegradable resin particles, measured according to the following measurement method 3, is 1.50 to 1.70: [Measurement Method 1] 1) The biodegradable resin composition is placed between a pair of molds having dimensions of 60 mm laterally × 60 mm longitudinally, and then the biodegradable resin sample having an average thickness of 2 mm is manufactured at 180°C under a pressure of 20 MPa; 2) Remove the biodegradable resin sample from the mold and, after 24 hours, calculate the transverse shrinkage rate and the longitudinal shrinkage rate of the biodegradable resin sample; 3) The molding shrinkage rate of the biodegradable resin sample is calculated according to the following equation 1: [Equation 1] Molding shrinkage rate of biodegradable resin sample (%) = (transverse shrinkage rate + longitudinal shrinkage rate) / 2 Wherein the transverse shrinkage rate is calculated by the following equation 2, and the longitudinal shrinkage rate is calculated by the following equation 3: [Equation 2] Transverse shrinkage rate (%) = (transverse length of biodegradable resin sample after 24 hours (mm) / 60 mm) × 100 [Equation 3] Longitudinal shrinkage rate (%) = (longitudinal length of biodegradable resin sample after 24 hours (mm) / 60 mm) × 100, [Measurement Method 3] 1) Extrude the biodegradable resin composition at 175 ºC and then cool it at 5 ºC to form the biodegradable resin granules, 2) According to ASTM D792 standard, at 23 The specific gravity of the biodegradable resin particles was measured at °C.

2. The biodegradable resin composition according to claim 1, wherein the biodegradable resin composition comprises a first biodegradable resin and a second biodegradable resin in a weight ratio of 90:10 to 10:

90.

3. The biodegradable resin composition according to claim 1, wherein the first coefficient of thermal expansion of the biodegradable resin sample, measured according to the following measurement method 2, is 75 to 290: [Measurement Method 2] 1) Cutting the biodegradable resin sample into dimensions of 20 mm transverse × 4 mm longitudinal × 0.7 mm thickness to prepare the biodegradable resin sample; 2) Measuring the first coefficient of thermal expansion of the biodegradable resin sample in the range of 10 °C to 40 °C using a thermomechanical analyzer while heating from 0 °C to 100 °C at a rate of 5 °C / min.

4. The biodegradable resin composition according to claim 3, wherein the second coefficient of thermal expansion of the biodegradable resin sample, measured according to the above-described measurement method 2, is 100 to 1,000 in the range of 80 ºC to 100 ºC.

5. A biodegradable cosmetic container made of a biodegradable resin composition, said biodegradable resin composition comprising: The first biodegradable resin has a glass transition temperature of -15 ºC or lower. A second biodegradable resin, different from the first biodegradable resin; and an inorganic filler, wherein the first biodegradable resin contains PBAT resin, the second biodegradable resin contains PLA resin with a glass transition temperature (Tg) of 50°C or higher, wherein the inorganic filler contains CaCO3, and the content of the inorganic filler is 40 wt% to 90 wt% based on the total weight of the biodegradable resin composition, wherein the molding shrinkage of the biodegradable resin sample, measured according to the following measurement method 1, is 0.5% or less, and wherein the specific gravity of the biodegradable resin particles, measured according to the following measurement method 3, is 1.50 to 1.70: [Measurement Method 1] 1) The biodegradable resin composition is placed between a pair of molds having dimensions of 60 mm laterally × 60 mm longitudinally, and then the biodegradable resin sample having an average thickness of 2 mm is manufactured at 180°C under a pressure of 20 MPa; 2) Remove the biodegradable resin sample from the mold and, after 24 hours, calculate the transverse shrinkage rate and the longitudinal shrinkage rate of the biodegradable resin sample; 3) The molding shrinkage rate of the biodegradable resin sample is calculated according to the following Equation 1: [Equation 1] Molding shrinkage rate of biodegradable resin sample (%) = (transverse shrinkage rate + longitudinal shrinkage rate) / 2 In Equation 1, the transverse shrinkage rate is calculated by the following Equation 2, and the longitudinal shrinkage rate is calculated by the following Equation 3: [Equation 2] Transverse shrinkage rate (%) = (transverse length of biodegradable resin sample after 24 hours (mm) / 60 mm) × 100 [Equation 3] Longitudinal shrinkage rate (%) = (longitudinal length of biodegradable resin sample after 24 hours (mm) / 60 mm) × 100, [Measurement Method 3] 1) Extrude the biodegradable resin composition at 175 ºC and then cool it at 5 ºC to form the biodegradable resin granules, 2) According to ASTM The D792 standard measures the specific gravity of the biodegradable resin particles at 23 °C.

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