Biodegradable resin composition and biodegradable molded article including the same

Abstract

To provide a biodegradable resin composition having excellent dimensional stability and mechanical properties and a biodegradable molded article including the same.SOLUTION: The present invention provides a biodegradable resin composition comprising a first biodegradable resin having a glass transition temperature (Tg) of -15°C or lower, and an inorganic filler, wherein the mold shrinkage ratio of a biodegradable resin specimen measured according to a specified measurement method is 1.0% or less, and a biodegradable molded article including the same.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a biodegradable resin composition and a biodegradable molded article containing the same.

Background Art

[0002] In recent years, as concerns about environmental problems have increased, solutions to the disposal problems of various daily necessities, particularly disposable products, have been demanded. Specifically, petroleum-based polymer materials are inexpensive and have excellent properties such as processability, and are widely used to manufacture various products such as films, fibers, packaging materials, bottles, and containers. However, when the life of the used products has ended, harmful substances are emitted during incineration, and it takes hundreds of years depending on the type to be completely decomposed naturally, which has the disadvantage.

[0003]

[0004] To overcome the limitations of these petroleum-based polymer materials, research on biodegradable resins that are decomposed in a relatively short period has been actively conducted. As biodegradable resins, polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), etc. have been introduced as alternatives. However, since PLA is inferior in flexibility and PBAT has poor mechanical properties, the applications of use have been limited. To improve such problems, U.S. Patent No. 9,096,758 used a small amount of an inorganic filler mixed with PBAT as a biodegradable resin composition. However, due to still low mechanical properties and low resistance to moisture, there was a limit to replacing conventional petroleum-based polymer materials.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

SUMMARY OF THE INVENTION

PROBLEM TO BE SOLVED BY THE INVENTION

[0006] The present invention provides a biodegradable resin composition excellent in dimensional stability and mechanical properties, and a biodegradable molded article containing the same.

MEANS FOR SOLVING THE PROBLEM

[0007] The biodegradable resin composition according to the present invention includes a first biodegradable resin having a glass transition temperature (Tg) of -15°C or lower and an inorganic filler, and the mold shrinkage rate of a biodegradable resin specimen measured by the following measurement method 1 is 1.0% or lower.

[0008] [Measurement Method 1] 1) After disposing the biodegradable resin composition between a pair of molds having a size of 60 mm in the lateral direction and 60 mm in the longitudinal direction, a biodegradable resin specimen having an average thickness of 2 mm is produced under the temperature condition of 180°C and the pressure condition of 20 Mpa.

[0009] 2) After the biodegradable resin specimen is removed from the mold and 24 hours have elapsed, the shrinkage rate in the lateral direction and the shrinkage rate in the longitudinal direction of the biodegradable resin specimen are calculated.

[0010] 3) The mold shrinkage rate of the biodegradable resin specimen is calculated by the following formula 1.

[0011] [Formula 1] Mold shrinkage rate of biodegradable resin specimen (%) = (Shrinkage rate in lateral direction + Shrinkage rate in longitudinal direction) / 2

[0012] In the above formula 1, the shrinkage rate in the lateral direction is calculated by the following formula 2, and the shrinkage rate in the longitudinal direction is calculated by the following formula 3, respectively.

[0013] [Formula 2] Shrinkage rate in lateral direction (%) = (Length of biodegradable resin specimen in lateral direction (mm) after 24 hours have elapsed / 60 mm) × 100

[0014] [Formula 3] Longitudinal shrinkage rate (%) = (Longitudinal length (mm) of the biodegradable resin specimen after 24 hours / 60 mm) × 100

[0015] In one embodiment of the present invention, the mold shrinkage rate of the biodegradable resin specimen may be 0.5% or less.

[0016] In one embodiment of the present invention, based on the total weight of the biodegradable resin composition, the content of the inorganic filler may be 10% by weight to 90% by weight.

[0017] In one embodiment of the present invention, the biodegradable resin composition may contain the first biodegradable resin and the inorganic filler in a weight ratio of 90:10 to 30:70.

[0018] In one embodiment of the present invention, the biodegradable resin composition contains a second biodegradable resin different from the first biodegradable resin, and the second biodegradable resin may have a glass transition temperature (Tg) of 50°C or higher.

[0019] In one embodiment of the present invention, the second biodegradable resin may have a flexural strength of 50 MPa or higher according to ASTM D790.

[0020] In one embodiment of the present invention, the second biodegradable resin may have a flexural modulus of 2,500 MPa or higher according to ASTM D790.

[0021] In one embodiment of the present invention, the biodegradable resin composition may contain the first biodegradable resin and the second biodegradable resin in a weight ratio of 90:10 to 10:90.

[0022] In one embodiment of the present invention, the first coefficient of thermal expansion of a sample of the biodegradable resin specimen measured by the following measuring method 2 may be 75 μm / (m·°C) to 290 μm / (m·°C).

[0023] [Measuring method 2] 1) Cut the biodegradable resin specimen into a size of 20 mm in the transverse direction × 4 mm in the longitudinal direction × 0.7 mm in thickness to produce a sample of the biodegradable resin specimen.

[0024] 2) Using a thermomechanical analyzer, while heating the sample of the biodegradable resin specimen from 0°C to 100°C at a rate of 5°C / min, measure the first coefficient of thermal expansion in the range of 10°C to 40°C.

[0025] In one embodiment of the present invention, the second coefficient of thermal expansion of the sample of the biodegradable resin specimen in the range of 80°C to 100°C measured by the measuring method 2 may be 100 μm / (m·°C) to 1,000 μm / (m·°C).

[0026] In one embodiment of the present invention, the specific gravity of the biodegradable resin pellets measured by the following measuring method 3 may be 1.30 to 2.00.

[0027] [Measuring method 3] 1) After extruding the biodegradable resin composition at 175°C, cool it at 5°C to produce biodegradable resin pellets.

[0028] 2) Measure the specific gravity of the biodegradable resin pellets at 23°C according to ASTM D792.

[0029] The biodegradable molded article according to the present invention includes a first biodegradable resin having a glass transition temperature (Tg) of -15°C or lower and an inorganic filler, and includes a biodegradable resin composition having a mold shrinkage rate of 1.0% or lower of a biodegradable resin specimen measured by the following measuring method 1.

[0030] [Measuring method 1] 1) After placing the biodegradable resin composition between a pair of molds having a size of 60 mm in the lateral direction and 60 mm in the longitudinal direction, a biodegradable resin specimen having an average thickness of 2 mm is produced under the temperature condition of 180° C. and the pressure condition of 20 MPa.

[0031] 2) After the biodegradable resin specimen is removed from the mold, the shrinkage rate in the lateral direction and the shrinkage rate in the longitudinal direction of the biodegradable resin specimen after 24 hours have elapsed are calculated.

[0032] 3) Calculate the mold shrinkage rate of the biodegradable resin specimen according to the following formula 1.

[0033] [Formula 1] Mold shrinkage rate of biodegradable resin specimen (%) = (Shrinkage rate in lateral direction + Shrinkage rate in longitudinal direction) / 2

[0034] In the formula 1, the shrinkage rate in the lateral direction is calculated according to the following formula 2, and the shrinkage rate in the longitudinal direction is calculated according to the following formula 3, respectively.

[0035] [Formula 2] Shrinkage rate in lateral direction (%) = (Length of biodegradable resin specimen in lateral direction (mm) after 24 hours have elapsed / 60 mm) × 100

[0036] [Formula 3] Shrinkage rate in longitudinal direction (%) = (Length of biodegradable resin specimen in longitudinal direction (mm) after 24 hours have elapsed / 60 mm) × 100

[0037] In one embodiment of the present invention, the biodegradable molded article may be a non-woven fabric, a vacuum-formed sheet, a blow-molded article, or an injection-molded article.

Effect of the Invention

[0038] The biodegradable resin composition according to the present invention includes a biodegradable resin whose glass transition temperature is adjusted to be below a specific range, so that the biodegradability, tensile strength, and elongation rate are improved, and the biodegradable molded article including the biodegradable resin composition may be easily decomposed when discarded.

[0039] In addition, the biodegradable resin composition according to the present invention contains a biodegradable resin whose glass transition temperature is adjusted to be equal to or lower than a specific range, and the mold shrinkage rate is controlled to be equal to or lower than a specific range. As a result, during injection molding, the volume change can be minimized, the flexural strength and flexural modulus can be improved, the elongation at break and impact strength can be improved, and the mechanical properties can be improved.

[0040] In addition, the biodegradable resin composition according to the present invention contains a high content of an inorganic filler, so that the dimensional stability at normal temperature and high temperature can be improved, and it can be more preferably used for products of containers that require storage functions, durability, etc. due to their high specific gravity.

Embodiments for Carrying Out the Invention

[0041] The structural or functional descriptions of the embodiments disclosed in this specification or the application are merely exemplified for the purpose of explaining the embodiments according to the technical idea of the present invention. The embodiments according to the technical idea of the present invention can be implemented in various forms in addition to the embodiments disclosed in this specification or the application, and the technical idea of the present invention is not construed as being limited to the embodiments described in this specification or the application.

[0042] When a component in this specification or the application is described as "including", unless otherwise stated, this does not exclude other components, but means that other components may also be further included. In addition, any numerical range indicating physical property values, dimensions, etc. of the components described in this specification or the application must be understood to be modified by the term "about" unless otherwise stated.

[0043] "ppm" in this specification or the application means a weight basis.

[0044] The description of "A and / or B" in this specification or the application means "A, B, or A and B".

[0045] Hereinafter, the biodegradable resin composition according to the present invention and the biodegradable molded article containing the same will be described.

[0046] The biodegradable resin composition according to the present invention includes a first biodegradable resin having a glass transition temperature (Tg) of -15°C or lower and an inorganic filler, and the mold shrinkage rate of a biodegradable resin specimen measured by the following Measuring Method 1 is 1.0% or lower.

[0047] [Measuring Method 1] 1) After arranging the biodegradable resin composition between a pair of molds having a size of 60 mm in the lateral direction and 60 mm in the longitudinal direction, a biodegradable resin specimen having an average thickness of 2 mm is produced under the conditions of a temperature of 180°C and a pressure of 20 MPa.

[0048] 2) After the biodegradable resin specimen is removed from the mold, the shrinkage rate in the lateral direction and the shrinkage rate in the longitudinal direction of the biodegradable resin specimen after 24 hours have elapsed are calculated.

[0049] 3) The mold shrinkage rate of the biodegradable resin specimen is calculated by the following Formula 1.

[0050] [Formula 1] Mold shrinkage rate of biodegradable resin specimen (%) = (Shrinkage rate in lateral direction + Shrinkage rate in longitudinal direction) / 2

[0051] In Formula 1 above, the shrinkage rate in the lateral direction is calculated by the following Formula 2, and the shrinkage rate in the longitudinal direction is calculated by the following Formula 3.

[0052] [Formula 2] Shrinkage rate in lateral direction (%) = (Length of biodegradable resin specimen in lateral direction (mm) after 24 hours have elapsed / 60 mm) × 100

[0053] [Formula 3] Shrinkage rate in longitudinal direction (%) = (Length of biodegradable resin specimen in longitudinal direction (mm) after 24 hours have elapsed / 60 mm) × 100

[0054] The biodegradable resin composition contains a first biodegradable resin having a glass transition temperature (Tg) of -15°C or lower. The glass transition temperature of the first biodegradable resin may be -15°C or lower, -15°C to -50°C, -20°C to -50°C, -20°C to -48°C, -25°C to -45°C, or -26°C to -42°C.

[0055] The glass transition temperature (Tg) is measured using a Differential Scanning Calorimeter (DSC). After heating from 40°C to 180°C at a rate of 10°C / min, it is isothermal for 5 minutes to perform a primary heat history removal process. Then, it is cooled from 180°C to -50°C at a rate of 10°C / min, isothermal for 5 minutes, and after the cooling process, while heating from -50°C to 180°C at a rate of 10°C / min, the first endothermic temperature is measured.

[0056] The first biodegradable resin may contain a diol, an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid.

[0057] The first biodegradable resin may contain a first repeating unit and a second repeating unit. The first repeating unit may contain a diol component and an aromatic dicarboxylic acid component, and the second repeating unit may contain a diol component and an aliphatic dicarboxylic acid component.

[0058] The number of the first repeating units may be 100 to 620, 150 to 600, 150 to 550, 150 to 500, 170 to 480, or 171 to 476.

[0059] The number of the second repeating units may 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.

[0060] When the above range is satisfied, the glass transition temperature (Tg) of the first biodegradable resin can be adjusted to -15 °C or lower, and the crystallinity of the biodegradable resin composition is reduced, whereby the tensile strength and elongation can be improved.

[0061] The diol component may contain 1,4-butanediol or a derivative thereof. The diol component may contain 95 mol% or more, 97 mol% or more, 98 mol% or more, 99 mol% or more, or 100 mol% of 1,4-butanediol or a derivative thereof based on the total number of moles of the diol component. By containing 1,4-butanediol or a derivative thereof, the biodegradability, flexibility, and strength can be improved, and when the diol component consists only of 1,4-butanediol, the effects of improving biodegradability and strength can be maximized.

[0062] The diol component may further contain a second diol different from the first diol which is 1,4-butanediol or a derivative thereof. The second diol may be at least one selected from the group consisting of propanediol, hexanediol, cyclohexanedimethanol, and ethylene glycol. Specifically, the second diol may be at least one 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-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, and ethylene glycol. The diol component may contain 5 mol% or less, 3 mol% or less, 2 mol% or less, or 1 mol% or less of the second diol based on the total number of moles of the diol component.

[0063] The aromatic dicarboxylic acid component may be one or more selected from the group consisting of terephthalic acid, dimethyl terephthalic acid, and derivatives thereof. Specifically, the aromatic dicarboxylic acid component may be terephthalic acid or dimethyl terephthalic acid. The dicarboxylic acid component may contain the aromatic dicarboxylic acid component in an amount of 15 mol% or more, 30 mol% or more, 45 mol% or more, 50 mol% or more, or 75 mol% or more, based on the total number of moles of the dicarboxylic acid component, and may contain it in an amount of 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%.

[0064] The aliphatic dicarboxylic acid component may be one or more selected from the group consisting of adipic acid, succinic acid, and derivatives thereof. Specifically, the aliphatic dicarboxylic acid component may be adipic acid or succinic acid. The dicarboxylic acid component may contain the aliphatic dicarboxylic acid component in an amount of 15 mol% or more, 30 mol% or more, 45 mol% or more, 50 mol% or more, or 75 mol% or more, based on the total number of moles of the dicarboxylic acid component, and may contain it in an amount of 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%.

[0065] The molar ratio of the aromatic dicarboxylic acid component to the aliphatic dicarboxylic acid component may 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.

[0066] The molar ratio of the diol component to the dicarboxylic acid component may 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 the above range is satisfied, the biodegradable resin composition has no discoloration such as yellowing, and the biodegradability, strength, and processability can all be improved.

[0067] The biodegradable resin may include polybutylene adipate terephthalate (PBAT) in which the first repeating unit includes a diol component and an aromatic dicarboxylic acid component, and the second repeating unit includes a diol component and an aliphatic dicarboxylic acid component.

[0068] Specifically, the polybutylene adipate terephthalate may include a unit represented by the following Chemical Formula 1.

[0069]

Chemical Formula

[0070] In Chemical Formula 1, m is 1 to 20, and n may be 1 to 20.

[0071] The biodegradable resin composition includes a second biodegradable resin different from the first biodegradable resin, and the second biodegradable resin may have a glass transition temperature (Tg) of 50°C or higher. The glass transition temperature of the second biodegradable resin may be 50°C or higher, 50°C to 80°C, 50°C to 75°C, 50°C to 70°C, 55°C to 70°C, or 55°C to 65°C. When the above range is satisfied, in the process of cooling the biodegradable resin composition, the fluidity of the polymer chains can be reduced, and the volume change in the process of injection molding the biodegradable resin composition can be minimized.

[0072] The second biodegradable resin may have a flexural strength according to ASTM D790 of 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 to 150 MPa or lower.

[0073] The second biodegradable resin may have a flexural modulus according to ASTM D790 of 2,500 MPa or more, 2,800 MPa or more, 3,000 MPa or more, 3,200 MPa or more, 3,300 MPa or more, or may be 3,300 MPa or more to 4,000 MPa or less.

[0074] When the above range is satisfied, mechanical properties such as the flexural strength and flexural modulus of the first biodegradable resin can be complemented.

[0075] The biodegradable resin composition may contain the first biodegradable resin and the 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 the above range is satisfied, it is excellent in elongation at break and impact strength, the brittleness is improved, and the processability can be improved. Also, the flexural strength and flexural modulus can be improved.

[0076] The biodegradable resin composition may have a flexural strength according to ASTM D790 of 9 MPa or more, 10 MPa or more, 20 MPa or more, 25 MPa or more, 30 MPa or more, or may be 9 MPa or more to 50 MPa or less.

[0077] The biodegradable resin composition may have a flexural modulus according to ASTM D790 of 150 MPa or more, 200 MPa or more, 250 MPa or more, 300 MPa or more, 800 MPa or more, or may be 310 MPa or more to 1,000 MPa or less.

[0078] The biodegradable resin composition may have a weight-average molecular weight that varies depending on the weight ratio of the first biodegradable resin and the second biodegradable resin. Further, the biodegradable resin composition may have a flexural strength and / or a flexural modulus that vary depending on the weight-average molecular weight and / or the degree of bonding between the first biodegradable resin and the second biodegradable resin. Further, the biodegradable resin composition can adjust the mold shrinkage rate of a biodegradable resin specimen described later as the flexural strength and / or the flexural modulus change.

[0079] The second biodegradable resin may contain one or more selected from the group consisting of polybutylene azelate terephthalate (PBAzT), polybutylene sebacate terephthalate (PBSeT), polybutylene succinate terephthalate (PBST), polyhydroxyalkanoate (PHA), and polylactic acid (PLA).

[0080] The polylactic acid may be a high-melting-point polylactic acid having a stereocomplex crystal. Further, the polylactic acid may be formed by solution mixing or melt mixing of poly-L-lactic acid and poly-D-lactic acid.

[0081] Specifically, the polylactic acid may contain a unit represented by the following Chemical Formula 2.

[0082]

Chemical Formula

[0083] The polylactic acid may be a polymer containing L-lactic acid units and / or D-lactic acid units. The polylactic acid may contain poly-L-lactic acid and / or poly-D-lactic acid.

[0084] When the biodegradable resin composition is applied to injection products, the content of the poly-D-lactic acid in the polylactic acid may be more than about 0 wt% to about 2 wt% or less, more than about 0 wt% to about 1.9 wt% or less, more than about 0 wt% to about 1.8 wt% or less, or more than about 0 wt% to about 1.7 wt% or less.

[0085] When the biodegradable resin composition is applied to extrusion products such as nonwoven fabrics, thermoformed sheets, or blow-molded products, the content of the poly-D-lactic acid in the 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.

[0086] When the above ranges are satisfied, the thermal and mechanical properties are excellent, appropriate fluidity in the required processes can be imparted, and the processability can be improved.

[0087] The poly-L-lactic acid may be a polymer mainly containing L-lactic acid units. The poly-L-lactic acid may contain L-lactic acid units at a content 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%. The poly-L-lactic acid may contain D-lactic acid units and / or units other than lactic acid. The poly-L-lactic acid may contain the D-lactic acid units and / or units other than lactic acid at a content 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%.

[0088] The poly D-lactic acid may be a polymer mainly containing D-lactic acid units. The poly D-lactic acid may contain the D-lactic acid units at a content 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%, or about 97 mol% to about 100 mol%. The poly D-lactic acid may contain the L-lactic acid units and / or units other than lactic acid. The poly D-lactic acid may contain the L-lactic acid units and / or units other than lactic acid at a content 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%.

[0089] The units other than lactic acid may be units derived from dicarboxylic acids having a functional group capable of forming two or more ester bonds, polyhydric alcohols, hydroxycarboxylic acids, lactones, etc., and units derived from various polyesters, various polyethers, various polycarbonates, etc. composed of these various components.

[0090] Examples of the dicarboxylic acid include succinic acid, adipic acid, azelaic acid, sebacic acid, terephthalic acid, isophthalic acid, etc. Examples of the polyhydric alcohol include aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, octanediol, glycerin, sorbitan, neopentyl glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, etc., or aromatic polyhydric alcohols such as those obtained by adding ethylene oxide to bisphenol.

[0091] Examples of the hydroxycarboxylic acid include glycolic acid and hydroxybutyric acid. Examples of the lactone include glycolide, ε-caprolactone glycolide, ε-caprolactone, β-propiolactone, δ-butyrolactone, β- or γ-butyrolactone, pivalolactone, δ-valerolactone, and the like.

[0092] The polylactic acid may be commercially available under the name of BIOMER L9000 from Biomer, Incorporated. TM Alternatively, the polylactic acid may be commercially available from Natureworks LLC (Natureworks (registered trademark)) or Mitsui Chemical (Lacea TM ). Further, the polylactic acid may be the one 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, which are incorporated herein by reference in their entireties for all purposes.

[0093] The polylactic acid can be modified with a surface treatment agent.

[0094] The surface of the polylactic acid can be modified with the surface treatment agent. By including the polylactic acid with the surface treatment agent in the biodegradable resin composition, the compatibility with the first biodegradable resin can be improved, and the bleeding phenomenon in which the polylactic acid flows out on the surface of the molded product to be manufactured can be suppressed.

[0095] The surface treatment agent may contain an amide group. The surface treatment agent may contain a fatty acid amide. The surface treatment agent containing an amide group easily binds to the functional group of the polylactic acid, and the surface of the polylactic acid can be more easily modified. Thereby, the compatibility with the first biodegradable resin can be improved, and the bleeding phenomenon can be further suppressed.

[0096] The surface-modified polylactic acid can be produced by the following method.

[0097] A surface treatment agent may be added to the polylactic acid, and the polylactic acid and the surface treatment agent may be stirred so that the surface treatment agent is bonded to the surface of the polylactic acid.

[0098] The stirring temperature may be from the melting point of the surface treatment agent to the melting point of the surface treatment agent + 50°C. The addition amount of the surface treatment agent may be 0.1 part by weight to 5 parts by weight, 0.1 part by weight to 4 parts by weight, 0.1 part by weight to 3 parts by weight, or 0.5 part by weight to 3 parts by weight based on 100 parts by weight of the polylactic acid.

[0099] The stirring time may be about 1 minute to about 60 minutes, about 1 minute to about 50 minutes, about 5 minutes to about 50 minutes, or about 5 minutes to about 40 minutes.

[0100] The polyhydroxyalkanoate may contain a unit represented by the following Chemical Formula 3.

[0101]

Chemical Formula

[0102] In Chemical Formula 3, R is independently selected from the group consisting of a hydrogen atom, a hydrocarbon group, a hetero atom, and combinations thereof, n is the number of repeating units from 1 to 35,000, and x can represent a constant from 1 to 5.

[0103] The polyhydroxyalkanoate may be a homopolymer or copolymer composed of at least one moiety 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. Also, the at least one moiety may have the same or different number of repeating units.

[0104] The polyhydroxyalkanoate may be a copolymer containing 3-hydroxybutyrate units and 3-hydroxyhexanoate units as main constituent units.

[0105] The polyhydroxyalkanoate may contain 80 mol% or more of 3-hydroxybutyrate units as a constituent component. The polyhydroxyalkanoate may contain 3-hydroxybutyrate units at a content of about 85 mol% or more.

[0106] The polyhydroxyalkanoate may be poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) copolymer resin, or poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate) copolymer resin.

[0107] The polyhydroxyalkanoate can be produced by, for example, microorganisms such as Alcaligenes eutrophus AC32 strain (International Deposit under the Budapest Treaty, International Deposit Authority: Patent Biological Deposit Center of the National Institute of Advanced Industrial Science and Technology (1-1-1 Higashi 1-chome, Tsukuba, Ibaraki, Japan), original deposit date: August 12, 1996, transferred on August 7, 1997, deposit number FERM BP-6038 (transferred from the original deposit FERM P-15786)) (J. Bacteriol., 179, 4821 (1997)) in which the PHA synthase gene derived from Aeromonas caviae is introduced into Alcaligenes eutrophus.

[0108] The polyhydroxyalkanoate can be obtained from commercially available products. Commercially available products of the polyhydroxyalkanoate include "NODAX" of Danimer, "ENMAT" of Tianan biopolymer, "PHACT" of CJ CheilJedang, "Aonilex (registered trademark) X131N", "Aonilex (registered trademark) X131A", "Aonilex (registered trademark) 151A", "Aonilex (registered trademark) 151C", "PHBH (registered trademark) X331N", "PHBH (registered trademark) X131A", "PHBH (registered trademark) 151A", or "PHBH (registered trademark) 151C" of Kaneka.

[0109] The biodegradable resin composition contains an inorganic filler. The inorganic filler can be used as a support for the first biodegradable resin or the first and second biodegradable resins contained in the biodegradable resin composition. Therefore, the crystallinity of the biodegradable resin composition can be adjusted, and the dimensional stability at normal temperature and high temperature can be improved.

[0110] The content of the inorganic filler may be 10% by weight to 90% by weight, 20% by weight to 90% by weight, 30% by weight to 90% by weight, 40% by weight to 90% by weight, 40% by weight to 80% by weight, or 47% by weight to 70% by weight based on the total weight of the biodegradable resin composition. When the above range is satisfied, the dimensional stability at normal temperature and high temperature can be improved, the specific gravity increases, and it can be more suitably used for cosmetic container products that require durability and the like.

[0111] The biodegradable resin composition may contain the first biodegradable resin and the 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 the above range is satisfied, the crystallinity of the biodegradable resin composition can be improved, and the dimensional stability at normal temperature and high temperature can be improved.

[0112] The specific surface area of the inorganic filler is 0.1 m 2 / g to 10.0 m 2 / g, 0.1 m 2 / g to 9.0 m 2 / g, 0.1 m 2 / g to 8.0 m 2 / g, 0.1 m 2 / g to 7.0 m 2 / g, 0.1 m 2 / g to 6.0 m 2 / g, 0.1 m 2 / g to 5.0 m 2 / g, 0.1 m 2 / g to 4.0 m 2 / g, or 0.1 m 2 / g to 3.0 m 2 / g. The specific surface area can be measured by the nitrogen gas adsorption method. When the above range is satisfied, it can be easily dispersed in the biodegradable resin, the biodegradability of the biodegradable resin is promoted, and the processability can be improved.

[0113] The average particle diameter of the inorganic filler may be 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 diameter can be calculated from the measurement result of the specific surface area by the air permeability method using a specific surface area measuring device. When the above range is satisfied, the uniformity of the particle size can be improved without causing an increase in viscosity during kneading of the biodegradable resin and the inorganic filler.

[0114] The sphericity of the inorganic filler may 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 the above range is satisfied, a large number of fine voids generated at the interface between the biodegradable resin and the inorganic filler can be included, the biodegradability can be improved, and the strength and moldability of the molded product can be increased.

[0115] The inorganic filler may contain one or more selected from the group consisting of calcium carbonate, magnesium carbonate, zinc oxide, titanium oxide, silica, alumina, kaolin clay, talc, mica, wollastonite, aluminum hydroxide, magnesium hydroxide, aluminum silicate, magnesium silicate, calcium silicate, aluminum sulfate, magnesium sulfate, calcium sulfate, magnesium phosphate, barium sulfate, silica sand, zeolite, diatomaceous earth, sericite, white sand, calcium sulfite, potassium titanate, bentonite, graphite, and ferrite.

[0116] Preferably, the inorganic filler may contain calcium carbonate (CaCO 3 ). Generally, when a molded product is manufactured from a biodegradable resin composition, an acid component may be generated during biodegradation. The acid component reacts with the calcium carbonate to produce CO 2 and H 2O can be generated, and the molded product can further improve the biodegradation rate at the molecular unit. Further, the calcium carbonate can neutralize the acid component, reduce the environmental load, and prevent the acidification of the soil.

[0117] The calcium carbonate may be heavy calcium carbonate obtained by mechanically pulverizing or classifying natural calcium carbonate mainly composed of limestone, chalk, marble, shells, corals, etc., with CaCO 3 as the main component.

[0118] The calcium carbonate may be surface-treated with an organic acid. By being surface-treated with the organic acid, the dispersibility of the calcium carbonate in the biodegradable resin composition can be increased, and the reactivity with the biodegradable resin can be improved. The surface treatment can be carried out by physical methods such as plasma treatment and corona treatment, or chemical methods such as silane coupling agents, titanium coupling agents, and surfactants. Examples of the organic acid include higher fatty acids, higher fatty acid esters, higher fatty acid amides, and higher fatty acids. For example, it may be calcium stearate.

[0119] The surface-treated calcium carbonate may be produced by the following method.

[0120] First, calcium carbonate powder can be produced by a pulverization process. Thereafter, the calcium carbonate powder is classified to obtain calcium carbonate with desired particles.

[0121] Thereafter, the calcium carbonate may be heat-treated at about 200°C to about 800°C by a heating device selected from a kiln, an electric furnace, or a microwave oven. The heat treatment time may be about 5 minutes to about 30 minutes, about 7 minutes to about 15 minutes, or about 7 minutes to about 14 minutes. The heat treatment temperature may be about 250°C to about 700°C or about 300°C to about 600°C. By heat-treating the calcium carbonate under the above conditions, the moisture in the calcium carbonate can be easily removed, the organic acid can be easily bonded to the surface of the calcium carbonate, and the aggregation of the calcium carbonate can be minimized.

[0122] Thereafter, an organic acid can be added to the heat-treated calcium carbonate to perform a step of treating the surface of the calcium carbonate. The process temperature may be 70°C to about 130°C. The input amount of the organic acid may be about 0.5 parts by weight to about 5 parts by weight, about 0.5 parts by weight to about 4 parts by weight, about 0.5 parts by weight to about 3 parts by weight, about 0.5 parts by weight to about 2 parts by weight, about 0.6 parts by weight to about 5 parts by weight, about 0.6 parts by weight to about 4 parts by weight, about 0.6 parts by weight to about 3 parts by weight, about 0.6 parts by weight to about 2 parts by weight, about 0.7 parts by weight to about 5 parts by weight, about 0.7 parts by weight to about 4 parts by weight, about 0.7 parts by weight to about 3 parts by weight, or about 0.7 parts by weight to about 2 parts by weight based on 100 parts by weight of the calcium carbonate. The process time may be about 1 minute to about 60 minutes, about 10 minutes to about 30 minutes, or about 5 minutes to about 20 minutes.

[0123] Thereafter, the surface-treated calcium carbonate can undergo an additional step of pulverizing and classifying the aggregates aggregated in the surface treatment step. In the surface-treated calcium carbonate, the content of the organic acid may be about 0.1% by weight to about 3% by weight, about 0.1% by weight to about 2% by weight, about 0.1% by weight to about 1% by weight, about 0.2% by weight to about 3% by weight, about 0.2% by weight to about 2% by weight, about 0.2% by weight to about 1% by weight, about 0.3% by weight to about 3% by weight, about 0.3% by weight to about 2% by weight, or about 0.3% by weight to about 1% by weight based on the total weight.

[0124] The calcium carbonate surface-treated with the organic acid may be partially oxidized. The surface-treated calcium carbonate may contain partially calcium oxide (CaO). The proportion of the calcium oxide may 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 to 5% by volume or less, 0.01% by volume or more to 4% by volume or less, 0.01% by volume or more to 3% by volume or less, 0.01% by volume or more to 2% by volume or less, or 0.01% by volume or more to 1% by volume or less based on 100% by volume of the surface-treated calcium carbonate particles. The proportion of the calcium oxide can be measured by an EDTA (Ethylene diamine tetra acetic acid) titration method based on JIS R 9011. When the above range is satisfied, the surface uniformity of the calcium carbonate can be improved, the phenomenon of the organic acid eluting from the surface of the calcium carbonate can be minimized, and the water resistance can be improved.

[0125] The biodegradable resin composition may further contain a reinforcing material. The reinforcing material may be a fiber derived from biomass. The reinforcing material may contain nanocellulose. The nanocellulose may be a gel or dry powder of a natural nanocellulose, and the dispersion stability, strength, and processability of the biodegradable resin containing the nanocellulose can all be improved.

[0126] The diameter of the nanocellulose may 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 length of the nanocellulose may 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. When the above range is satisfied, the strength and heat dissipation strength of the biodegradable resin composition can be further improved.

[0127] The nano-cellulose may be a dry powder or a gel having aggregated secondary particles that are not single particles, and the size of the secondary particles may be 1 μm to 50 μm, 2 μm to 45 μm, or 5 μm to 50 μm. The nano-cellulose may be in the form of a lyophilized powder to reduce its volume for easy storage and transportation.

[0128] The average particle size of the nano-cellulose may be 200 nm or less, 190 nm or less, or 185 nm or more, and the particle size deviation may be 20% or less, 18% or less, or 16% or less. When the above ranges are satisfied, the dispersibility and durability of the nano-cellulose can be improved.

[0129] The nano-cellulose can function as a nucleating agent, improve the crystallization rate of the biodegradable resin composition, and increase the crystallization temperature of the biodegradable resin composition. The nano-cellulose may be one or more selected from the group consisting of cellulose nanocrystals, cellulose nanofibers, and microfibrillated cellulose. From the aspects of strength and thermal properties, preferably, the cellulose nanocrystals or the cellulose nanofibers may be used.

[0130] The nano-cellulose can perform a UV-resistant function and impart appropriate UV resistance, biodegradation rate, and hydrolysis rate to the biodegradable resin. The nano-cellulose may be one or more selected from the group consisting of hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, cellulose acetate, methyl cellulose, ethyl cellulose, propyl cellulose, butyl cellulose, pentyl cellulose, hexyl cellulose, and cyclohexyl cellulose.

[0131] The nano-cellulose may be pretreated with a bead mill or ultrasonically pretreated. The nano-cellulose may be one in which the water-dispersed nano-cellulose is pretreated with a bead mill or ultrasonically pretreated.

[0132] The nano-cellulose may be a dry powder having a particle size of 1 μm to 50 μm or a gel-like cellulose nanocrystal after being dispersed in water, and then may be pretreated with a bead mill or ultrasonic treatment. When the water-dispersed nano-cellulose is pretreated with a bead mill or ultrasonic treatment, the number of nano-cellulose particles can be increased, and the dispersibility can be maximized.

[0133] The nano-cellulose can be pretreated with a silane coupling agent of 0.01 to 10% by weight, 0.05 to 8% by weight, 0.1 to 8% by weight, 0.5 to 6% by weight, or 0.7 to 6% by weight based on the total weight of the nano-cellulose. When the above range is satisfied, the interfacial adhesion, dispersibility, and compatibility can be maximized, so that the mechanical properties and durability of the biodegradable resin composition containing the same can be further improved.

[0134] The biodegradable resin may contain the nano-cellulose at 0.01 to 3% by weight, 0.01 to 2.5% by weight, 0.05 to 2% by weight, 0.07 to 1.8% by weight, 0.1 to 1.2% by weight, 0.1 to 1% by weight, or 0.15 to 0.7% by weight based on the total weight of the biodegradable resin. When the above range is satisfied, the biodegradability and strength of the biodegradable resin composition can be further improved.

[0135] The biodegradable resin composition may contain an oligomer. The weight average molecular weight of the oligomer may be about 400 g / mol to about 1,300 g / mol. The oligomer may be contained in the biodegradable resin composition at 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 based on the weight of the biodegradable resin. The oligomer may be a reaction product of at least two or more of the diol, the aromatic dicarboxylic acid, and the aliphatic dicarboxylic acid. The oligomer may be a reaction product of 1,4-butanediol, terephthalic acid, and adipic acid.

[0136] The biodegradable resin composition may contain a plasticizer. The plasticizer can impart processability or flexibility to the molded article to be manufactured. The plasticizer may be glycerol, acrylate, glycerin, glycerol monostearate (GMS), sorbitol, or a mixture thereof. The plasticizer may be 0.1% by weight to 15% by weight, 0.1% by weight to 14% by weight, 0.1% by weight to 13% by weight, 0.1% by weight to 12% by weight, 0.1% by weight to 11% by weight, 0.1% by weight to 10% by weight, 0.1% by weight to 9% by weight, 0.1% by weight to 8% by weight, 0.1% by weight to 7% by weight, 0.1% by weight to 6% by weight, or 0.1% by weight to 5% by weight based on the total weight of the biodegradable resin composition. When the above range is satisfied, the elongation rate and heat drawing strength of the molded article produced from the biodegradable resin composition can be improved.

[0137] The biodegradable resin composition may contain an antioxidant. The antioxidant may contain one or more selected from the group consisting of phosphorus-based antioxidants, phenol-based antioxidants, and pentaerythritol-based antioxidants.

[0138] The phosphorus-based antioxidant may be one or more selected from the group consisting of triesters, diesters, monoesters of phosphorous acid such as triphenyl phosphate, trisnonylphenyl phosphate, tris(2,4-di-t-butylphenyl) phosphate, trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, triphenyl phosphate, tricresyl phosphate, tris(nonylphenyl) phosphate, and 2-ethylphenyldiphenyl phosphate.

[0139] The phenolic antioxidant may be one or more selected from the group consisting of α-tocopherol, butylhydroxytoluene, sinapyl alcohol, vitamin E, n-octadecyl 3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2-t-butyl-6-(3'-t-butyl-5'-methyl-2'-hydroxybenzyl)-4-methylphenyl acrylate, 2,6-di-t-butyl-4-(N,N-dimethylaminomethyl)phenol, 3,5-di-t-butyl-4-hydroxybenzylphosphonate diethyl ester, 2,2-bis(((3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoyl)oxy)methyl)propane-1,3-diyl bis(3-(3,5-di-tert)-butyl-4-hydroxyphenyl)propanoate), pentaerythritol tetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate), pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], and tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxymethyl]methane.

[0140] The antioxidant 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, nordihydroguaiaretic acid, epicatechin gallate, epigallocatechin gallate, epigallocatechin, propyl gallate, 2,3,5-trihydroxybutyrophenone, butylated hydroxyanisole, 4-hydroxymethyl-2,6-di-tert-butylphenol, α-tocopherol, resveratrol, rutin, astaxanthin, lycopene, β-carotene, and melatonin.

[0141] The content of the antioxidant may be 5% by weight or less, 4% by weight or less, 3% by weight or less, 2% by weight or less, 1.5% by weight or less, 1% by weight or less, 0.5% by weight or less, 0.3% by weight or less, 0 to 5% by weight, 0.01 to 4% by weight, 0.1 to 3% by weight, 1 to 3% by weight, 1 to 2% by weight, 0.01 to 0.3% by weight, 0.05 to 0.3% by weight, 0.15 to 0.3% by weight, or 0.2 to 0.3% by weight based on the total weight of the biodegradable resin composition.

[0142] The antioxidant may contain both the phosphorus-based antioxidant and the phenolic antioxidant. When the antioxidant contains both the phosphorus-based antioxidant and the phenolic antioxidant, 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 the above range is satisfied, it has the effect of delaying the oxidation phenomenon of the biodegradable resin composition in various temperature ranges.

[0143] The biodegradable resin composition may contain a heat stabilizer.

[0144] The heat stabilizer may be a phosphorus-based heat stabilizer. The heat stabilizer may contain one or more selected from the group consisting of amine-based high-temperature heat stabilizers such as tetraethylenepentamine, triethylphosphonoacetate, phosphoric acid, phosphorous acid, polyphosphoric acid, trimethyl phosphate, triethyl phosphate, trimethylphosphine, and triphenylphosphine. The heat stabilizer may be an antioxidant having an antioxidant function. The content of the heat stabilizer 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 based on the total weight of the biodegradable resin.

[0145] The biodegradable resin composition may contain a lubricant.

[0146] The lubricant may contain one or more selected from the group consisting of fatty acid lubricants containing stearic acid, aliphatic alcohol lubricants, aliphatic amide lubricants containing stearamide, n-butyl stearate, methyl hydroxystearate, polyhydric alcohol fatty acid esters, saturated fatty acid esters, aliphatic ester lubricants such as ester waxes, and fatty acid metal soap lubricants. Specifically, the lubricant may be a stearate lubricant and may contain one or more selected from the group consisting of calcium stearate, zinc stearate, barium stearate, magnesium stearate, glycerin stearate, and butyl stearate. The stearate lubricant can reduce the generation of heat due to friction during the mixing, melting, and processing of raw materials, is excellent in the dispersion effect on biodegradable resins compared to the price, is excellent in lubrication effect, and can improve manufacturing efficiency.

[0147] The content of the lubricant may be 5% by weight or less, 4% by weight or less, 3% by weight or less, 2% by weight or less, 1% by weight or less, less than 1% by weight, 0.9% by weight or less, 0.8% by weight or less, 0.7% by weight or less, 0.5% by weight or less, 0.3% by weight or less, or 0.1% by weight or less based on the total weight of the biodegradable resin composition. When the above range is satisfied, the physical properties of the biodegradable resin composition do not deteriorate, and the manufacturing efficiency can be improved.

[0148] The biodegradable resin composition may contain a flame retardant. The flame retardant may contain 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.

[0149] The halogen-based flame retardant may contain one or more selected from the group consisting of halogenated bisphenol compounds such as halogenated bisphenyl alkanes, halogenated bisphenyl ethers, halogenated bisphenyl thioethers, and halogenated bisphenyl sulfones, and bisphenol-bis(alkyl ether) compounds such as brominated bisphenol A, brominated bisphenol S, chlorinated bisphenol A, and chlorinated bisphenol S.

[0150] The phosphorus-based flame retardant may contain one or more selected from the group consisting of aluminum tris(diethylphosphate), bisphenol A bis(diphenyl phosphate), triaryl isopropyl phosphate, cresyl di(2,6-xylyl) phosphate, and aromatic condensed phosphate esters.

[0151] The metal hydrate may contain aluminum trihydrate, magnesium hydroxide, or a combination thereof.

[0152] The flame retardant may contain 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 as a flame retardant aid to improve the flame retardant effect.

[0153] The biodegradable resin composition may contain a foaming agent. The foaming agent may be mixed with the biodegradable resin composition in a molten state, or injected under pressure, and may undergo a phase change from a solid to a gas or from a liquid to a gas, or may be a gas itself, and can be used to control the foaming ratio (foaming density) of the foamed sheet.

[0154] The foaming agent may contain one or more selected from the group consisting of aliphatic hydrocarbons, cycloaliphatic hydrocarbons, halogenated hydrocarbons, inorganic gases, and water.

[0155] The biodegradable resin composition may contain a dispersant. The dispersant can improve the dispersibility of the solvent and the solute. The dispersant may contain one or more selected from the group consisting of aliphatic polyesters, polylactic acid, polyglycolic acid, polycaprolactone, and polyhydroxyalkanoates.

[0156] The dispersant may be contained in an amount of 1 to 20% by weight, 1 to 15% by weight, 1 to 13% by weight, 1 to 11% by weight, 2 to 10% by weight, 5 to 15% by weight, 7 to 12% by weight, 2 to 8% by weight, 5 to 8% by weight, or 2 to 5% by weight based on the total weight of the biodegradable resin composition.

[0157] The biodegradable resin composition may contain a chain extender. The chain extender may contain one or more selected from the group consisting of aromatic diisocyanates, aliphatic diisocyanates, isocyanurates, bisoxazolines, carboxylic anhydrides, and epoxides.

[0158] The aromatic diisocyanate may contain one or more selected from the group consisting of tolylene 2,4-diisocyanate, tolylene 2,6-diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, naphthylene 1,5-diisocyanate, and xylylene diisocyanate.

[0159] The aliphatic diisocyanate may contain one or more selected from the group consisting of 1,6-hexamethylene diisocyanate, isophorone diisocyanate, and methylene bis(4-isocyanatocyclohexane).

[0160] The isocyanurate may contain isophorone diisocyanate or methylene bis(4-isocyanatocyclohexane).

[0161] The bisoxazoline may contain 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.

[0162] The epoxy means an epoxy-containing copolymer based on at least one of styrene, acrylate, and methacrylate, and a copolymer having a glycidyl (meth)acrylate content of more than 20, more than 30, or more than 50% by weight is preferred.

[0163] The chain extender may be 1.5% by weight or less, 1.4% by weight or less, 1.3% by weight or less, 1.2% by weight or less, 1.1% by weight or less, 1% by weight or less, 0.9% by weight or less, 0.8% by weight or less, 0.7% by weight or less, 0.6% by weight or less, 0.5% by weight or less, 0.4% by weight or less, 0.3% by weight or less, based on the total weight of the biodegradable resin composition, or may be 0% to 1.5% by weight, 0.01% to 1.5% by weight, 0.1% to 1.5% by weight, 0.1% to 1.0% by weight, 0.1% to 0.9% by weight, 0.1% to 0.8% by weight, 0.1% to 0.7% by weight, 0.1% to 0.6% by weight, or 0.1% to 0.5% by weight.

[0164] The biodegradable resin composition may contain a hydrolysis inhibitor. When the weight average molecular weight (Mw) of the hydrolysis inhibitor is large, the volatility is low and the hydrolysis resistance can be improved. When the weight average molecular weight (Mw) of the hydrolysis inhibitor is small, the compatibility with the biodegradable resin can be increased.

[0165] As the hydrolysis inhibitor, two types of hydrolysis inhibitors with different weight average molecular weights can be used. For increasing the compatibility with the biodegradable resin, one type of hydrolysis inhibitor having 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, and one type of hydrolysis inhibitor having a weight average molecular weight of 10,000 g / mol or more, 20,000 g / mol or more, 30,000 g / mol or more, 40,000 g / mol or more, or 50,000 g / mol or more for improving low volatility and water resistance to hydrolysis can be used. The weight average molecular weight can be measured as a relative value to a standard PS (standard polystyrene) sample by GPC using THF as an eluent. When the above ranges are satisfied, the mechanical properties and water resistance to hydrolysis of the biodegradable resin composition can be improved.

[0166] The hydrolysis inhibitor may contain a carbodiimide compound. The carbodiimide compound can react with moisture and an acid and be converted into a urea structure, thereby reducing the reactivity between moisture and acid and the ester groups contained in the biodegradable resin. As a result, the phenomenon of hydrolysis of the biodegradable resin by moisture and acid can be reduced, and ultimately, the water resistance to hydrolysis of the biodegradable resin composition can be improved.

[0167] The carbodiimide compound may contain a compound represented by the following Chemical Formula 4.

[0168]

Chemical Formula

[0169] In Chemical Formula 4, n is a constant from 1 to 20.

[0170] The carbodiimide compound 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-diketylphenylcarbodiimide, N-toluyl-N' cyclohexylcarbodiimide, N,N'-di-2,6-diisopropylphenylcarbodiimide, N,N'-di-2,6-di-tert-butylphenylcarbodiimide, N-toluyl-N'-phenylcarbodiimide, N,N'-di-p-nitrophenylcarbodiimide, N,N'-di-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 a copolymer of benzene-2,4-diisocyanate-1,3,5-tris(1-methylethyl) homopolymer, 2,4-diisocyanate-1,3,5-tris(1-methylethyl), and 2,6-diisopropyldiisocyanate.

[0171] The weight average molecular weight (Mw) of the carbodiimide compound may be 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.

[0172] The content of the NCN group in the carbodiimide compound may 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 content of the NCN group in the carbodiimide compound can be measured by titration with oxalic acid. When the above range is satisfied, the water resistance of the biodegradable resin composition can be improved without reducing the compatibility with the biodegradable resin.

[0173] Based on the total weight of the biodegradable resin composition, the content of the hydrolysis inhibitor may 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 the above range is satisfied, the water resistance and the odor reduction effect of the biodegradable resin composition can be improved.

[0174] The biodegradable resin composition may contain a compound containing a urea group in an amount of 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% based on the total weight of the biodegradable resin composition. When the above range is satisfied, the proportion of the ester group contained in the biodegradable resin that can react with moisture or an acid decreases, and the water resistance can be improved.

[0175] The biodegradable resin composition has a mold shrinkage of the biodegradable resin specimen measured by the following Measuring Method 1 of 1.0% or less.

[0176] [Measuring Method 1] 1) After placing the biodegradable resin composition between a pair of molds having a size of 60 mm in the lateral direction and 60 mm in the longitudinal direction, a biodegradable resin specimen having an average thickness of 2 mm is manufactured under the conditions of a temperature of 180°C and a pressure of 20 MPa.

[0177] 2) After the biodegradable resin specimen is removed from the mold, the shrinkage rate in the lateral direction and the shrinkage rate in the longitudinal direction of the biodegradable resin specimen after 24 hours have elapsed are calculated.

[0178] 3) Calculate the mold shrinkage rate of the biodegradable resin specimen according to the following formula 1.

[0179] [Formula 1] Mold shrinkage rate of biodegradable resin specimen (%) = (Shrinkage rate in lateral direction + Shrinkage rate in longitudinal direction) / 2

[0180] In the above formula 1, the shrinkage rate in the lateral direction is calculated according to the following formula 2, and the shrinkage rate in the longitudinal direction is calculated according to the following formula 3, respectively.

[0181] [Formula 2] Shrinkage rate in lateral direction (%) = (Length of biodegradable resin specimen in lateral direction (mm) after 24 hours have elapsed / 60 mm) × 100

[0182] [Formula 3] Shrinkage rate in longitudinal direction (%) = (Length of biodegradable resin specimen in longitudinal direction (mm) after 24 hours have elapsed / 60 mm) × 100

[0183] The meaning of "after 24 hours have elapsed" for the biodegradable resin specimen may be an index of the normal cooling time in the injection molding when the biodegradable resin composition is manufactured into a biodegradable molded product by injection molding.

[0184] The meaning of the mold shrinkage rate of the biodegradable resin specimen may be an index showing the balance between dimensional stability and the physical properties in a trade-off relationship when the biodegradable resin composition is manufactured into a biodegradable molded product by the injection molding.

[0185] The above injection molding means a method of melting a biodegradable resin composition, injecting the melted biodegradable resin composition into a mold, and cooling for a certain period of time to produce a solidified biodegradable resin composition. The above injection molding can be affected by high temperature in the process of melting the biodegradable resin composition, and in the cooling process, workability, mechanical properties, dimensional stability, etc. may change depending on the properties of the biodegradable resin composition.

[0186] The biodegradable resin composition according to the present invention contains a first biodegradable resin having a glass transition temperature (Tg) of -15°C or lower, and the biodegradable molded article produced from the biodegradable resin composition is environmentally friendly and can exhibit excellent tensile strength and elongation. However, due to the characteristics of the first biodegradable resin having a low glass transition temperature, the fluidity of the polymer chains can change significantly during the cooling process, and it is inferior in dimensional stability due to a high shrinkage rate during injection molding, and there are limitations in the application to products.

[0187] Therefore, the biodegradable resin composition according to the present invention contains the first biodegradable resin having a glass transition temperature (Tg) of -15°C or lower and also contains an inorganic filler. By adjusting the mold shrinkage rate of the biodegradable resin specimen measured by the above measurement method 1 to 1.0% or less, when the biodegradable resin composition is produced into a biodegradable molded article by injection molding, the volume change can be minimized, and the dimensional stability at normal temperature and high temperature can be improved. In addition, the flexural strength, flexural modulus, and specific gravity are improved, the mechanical properties are improved, and it can be more suitably used for cosmetic container products that require storage functions, durability, etc.

[0188] The mold shrinkage rate of the biodegradable resin specimen may 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.

[0189] When the above range is satisfied, the dimensional stability can be improved without degrading the workability and mechanical properties.

[0190] The biodegradable resin composition may have a first coefficient of thermal expansion of a sample of a biodegradable resin specimen measured by the following Measuring Method 2 of 75 μm / (m·°C) to 290 μm / (m·°C).

[0191] [Measuring Method 2] 1) Cut the biodegradable resin specimen into a size of 20 mm in the lateral direction × 4 mm in the longitudinal direction × 0.7 mm in thickness to produce a sample of the biodegradable resin specimen.

[0192] 2) For the sample of the biodegradable resin specimen, while raising the temperature to 100 °C at a rate of 5 °C / min at 0 °C using a thermomechanical analyzer, measure the first coefficient of thermal expansion in the range of 10 °C to 40 °C.

[0193] The biodegradable resin composition may have a second coefficient of thermal expansion of a sample of the biodegradable resin specimen measured by the Measuring Method 2 in the range of 80 °C to 100 °C of 100 μm / (m·°C) to 1,000 μm / (m·°C).

[0194] The first coefficient of thermal expansion may be an index indicating the dimensional stability of the biodegradable resin composition at room temperature. The second coefficient of thermal expansion may be an index indicating the dimensional stability of the biodegradable resin composition at high temperature.

[0195] The first coefficient of thermal expansion may be 75 μm / (m·°C) to 290 μm / (m·°C), 90 μm / (m·°C) to 290 μm / (m·°C), 108 μm / (m·°C) to 250 μm / (m·°C), or 108 μm / (m·°C) to 214 μm / (m·°C). When the above range is satisfied, the dimensional stability during the cooling process of the biodegradable resin composition in the injection molding can be improved. The dimensional stability at room temperature can be improved by the second biodegradable resin described above.

[0196] The second coefficient of thermal expansion may be 100 μm / (m·°C) to 1,000 μm / (m·°C), 200 μm / (m·°C) to 1,000 μm / (m·°C), 300 μm / (m·°C) to 1,000 μm / (m·°C), 500 μm / (m·°C) to 900 μm / (m·°C), or 569 μm / (m·°C) to 871 μm / (m·°C). When the above range is satisfied, the dimensional stability in the process of melting the biodegradable resin composition in the injection molding can be improved. The dimensional stability at high temperatures can be improved by the combination of the first biodegradable resin and the second biodegradable resin described above.

[0197] The biodegradable resin composition may have a specific gravity of 1.30 to 2.00 for the biodegradable resin pellets measured by the following measuring method 3.

[0198] [Measuring Method 3] 1) After extruding the biodegradable resin composition at 175 °C, it is cooled at 5 °C to produce biodegradable resin pellets.

[0199] 2) According to ASTM D792, the specific gravity of the biodegradable resin pellets is measured at 23 °C.

[0200] The specific gravity may 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 the above range is satisfied, it can be more preferably used for cosmetic container products that require storage functions, durability, etc. The specific gravity can be adjusted by the content of the inorganic filler described above.

[0201] The biodegradable molded article according to the present invention can be produced from the biodegradable resin composition described above.

[0202] The biodegradable molded article includes a first biodegradable resin having a glass transition temperature (Tg) of -15 °C or lower and an inorganic filler, and includes a biodegradable resin composition having a mold shrinkage rate of 1.0% or lower for the biodegradable resin specimen measured by the following measuring method 1.

[0203] [Measurement Method 1] 1) After placing the biodegradable resin composition between a pair of molds having a size of 60 mm in the lateral direction and 60 mm in the longitudinal direction, a biodegradable resin specimen having an average thickness of 2 mm is produced under the temperature condition of 180°C and the pressure condition of 20 MPa.

[0204] 2) After the biodegradable resin specimen is removed from the mold, the shrinkage rate in the lateral direction and the shrinkage rate in the longitudinal direction of the biodegradable resin specimen after 24 hours have elapsed are calculated.

[0205] 3) Calculate the mold shrinkage rate of the biodegradable resin specimen according to the following formula 1.

[0206] [Formula 1] Mold shrinkage rate of biodegradable resin specimen (%) = (Shrinkage rate in lateral direction + Shrinkage rate in longitudinal direction) / 2

[0207] In the above formula 1, the shrinkage rate in the lateral direction is calculated according to the following formula 2, and the shrinkage rate in the longitudinal direction is calculated according to the following formula 3, respectively.

[0208] [Formula 2] Shrinkage rate in lateral direction (%) = (Length of biodegradable resin specimen in lateral direction (mm) after 24 hours have elapsed / 60 mm) × 100

[0209] [Formula 3] Shrinkage rate in longitudinal direction (%) = (Length of biodegradable resin specimen in longitudinal direction (mm) after 24 hours have elapsed / 60 mm) × 100

[0210] The first biodegradable resin, inorganic filler, mold shrinkage rate, and biodegradable resin composition may be the same as the first biodegradable resin, inorganic filler, mold shrinkage rate, and biodegradable resin composition described above.

[0211] The biodegradable molded product may be a non-woven fabric, a vacuum-formed sheet, a blow-molded product, or an injection-molded product.

[0212] The biodegradable molded article may be a biodegradable film. The thickness of the biodegradable film may be 5 μm to 500 μm, 5 μm to 400 μm, 5 μm to 350 μm, 10 μm to 350 μm, 15 μm to 350 μm, 20 μm to 350 μm, 25 μm to 300 μm, 30 μm to 300 μm, 35 μm to 300 μm, or 40 μm to 300 μm. The tensile strength of the biodegradable film may be 5 MPa or more, 7 MPa or more, 9 MPa or more, 10 MPa or more, 11 MPa or more, 100 MPa or less, 95 MPa or less, 90 MPa or less, or 5 MPa or more to 100 MPa or less. When the above ranges are satisfied, the film is not easily torn, has excellent mechanical properties, and is easily decomposed when the biodegradable molded article is discarded.

[0213] The elongation rate of the biodegradable film may be 85% or more, 90% or more, 95% or more, 1,000% or less, 950% or less, 900% or less, or 850% or less. The stretchability of the biodegradable molded article can be ensured, and it can withstand a certain load.

[0214] The biodegradable molded article may be a biodegradable sheet. The thickness of the biodegradable sheet may be 5 μm to 1,000 μm, 10 μm to 1,000 μm, 15 μm to 1,000 μm, 20 μm to 1,000 μm, 25 μm to 1,000 μm, 30 μm to 1,000 μm, 35 μm to 1,000 μm, or 40 μm to 1,000 μm. The tensile strength of the biodegradable sheet may be 5 MPa or more, 6 MPa or more, 9 MPa or more, 10 MPa or more, 11 MPa or more, 12 MPa or more, 55 MPa or less, 54 MPa or less, 53 MPa or less, 52 MPa or less, 51 MPa or less, or 50 MPa or less. The heat-drawing strength of the biodegradable sheet may be 100 N / cm or more, 110 N / cm or more, 120 N / cm or more, 130 N / cm or more, 140 N / cm or more, 150 N / cm or more, 700 N / cm or less, 650 N / cm or less, 600 N / cm or less, 550 N / cm or less, or 500 N / cm or less. When the above ranges are satisfied, the sheet is not easily torn, and it is easily decomposed when the biodegradable molded article is discarded.

[0215] The elongation rate of the biodegradable sheet may be 10% or more, 15% or more, 20% or more, 50% or less, 70% or more, 700% or less, 650% or less, 550% or less, 500% or less, or 450% or less. When the above range is satisfied, the stretchability of the biodegradable molded article can be ensured and it can withstand a certain load.

[0216] Preferably, the biodegradable molded article may be an injection-molded product, and the injection-molded product may be a cosmetic container. The biodegradable molded article has a high specific gravity and can be more preferably used for cosmetic container products that require storage functions, durability, etc.

[0217] The method for manufacturing a biodegradable molded article according to the present invention may include a step of subjecting a diol component and a dicarboxylic acid component to an esterification reaction to produce a prepolymer, a step of subjecting the prepolymer to a polycondensation reaction to produce a first biodegradable resin having a glass transition temperature (Tg) of -15°C or lower, a step of mixing the first biodegradable resin and an inorganic filler to produce a biodegradable resin composition, and a step of injecting the biodegradable resin composition.

[0218] The manufacturing method may include a step of subjecting a diol component and a dicarboxylic acid component to an esterification reaction to produce a prepolymer.

[0219] The diol component and the dicarboxylic acid component may be the same as the diol component and the dicarboxylic acid component in the biodegradable resin composition described above. The step can be carried out by removing the composition containing the diol component, the dicarboxylic acid component, and optionally the nanocellulose by a one-step esterification reaction, or by a two-step esterification reaction including a primary esterification reaction and a secondary esterification reaction.

[0220] The two-step esterification reaction may include a step of subjecting the diol component and the dicarboxylic acid component to a primary esterification reaction, and a step of adding the diol component and the dicarboxylic acid component to the reaction product of the above step to carry out a secondary esterification reaction.

[0221] When the biodegradable resin contains the nanocellulose, the binding force of the nanocellulose can be improved by adding the nanocellulose in the secondary esterification reaction stage. Further, by adding the nanocellulose dispersed in water in the secondary esterification reaction stage, the binding force of the nanocellulose can be further improved.

[0222] The nanocellulose can be added under the temperature conditions of 100°C to 160°C, 110°C to 140°C, or 110°C to 150°C. When the above range is satisfied, the solvent resistance can be improved.

[0223] The nanocellulose may be added at a rate of 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 the above range is satisfied, the efficiency of the manufacturing process can be improved without causing re-aggregation of the nanocellulose.

[0224] In this stage, a titanium-based catalyst, a germanium-based catalyst, an antimony-based catalyst, an additive, and a stabilizer can be added before the esterification reaction. The esterification reaction can be carried out in a temperature range 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 hour to 5 hours, 0.5 hour to 4.5 hours, 0.5 hour to 3.5 hours, or 1 hour to 3 hours, respectively. The esterification reaction can be carried out at normal pressure until the by-products water and methanol theoretically reach 90%.

[0225] The number-average molecular weight of the prepolymer may be 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 the above range is satisfied, the molecular weight of the prepolymer in the polycondensation reaction can be efficiently increased, and the strength characteristics can be improved.

[0226] The manufacturing method may include a step of subjecting the prepolymer to a polycondensation reaction to produce a first biodegradable resin.

[0227] The polycondensation reaction can be carried out in a temperature range of 180°C to 280°C, 190°C to 270°C, 210°C to 260°C, or 230°C to 255°C. The polycondensation reaction can be carried out in a pressure range of 1 Torr or less, 0.9 Torr or less, 0.7 Torr or less, 0.2 Torr to 1.0 Torr, 0.3 Torr to 0.9 Torr, or 0.5 Torr to 0.9 Torr. The polycondensation reaction 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.

[0228] The intrinsic viscosity of the first biodegradable resin produced in the above step may be 0.05 to 10 dL / gr. The melt viscosity of the first biodegradable resin is 100 s -1Under the conditions, when measured by an RDS (rheometrics dynamic spectrometer), it 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 more, 43,000 g / mol or more, 45,000 g / mol or more, or may be 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 more, 65,000 g / mol or more, 75,000 g / mol or more, 80,000 g / mol or more, or may be 85,000 g / mol to 100,000 g / mol. The polydispersity index (PDI) of the first biodegradable resin may be 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 satisfies the above ranges, the strength and processability can be further improved. The acid value of the first biodegradable resin may be 1.8 mgKOH / g or less, 1.5 mgKOH / g or less, 1.3 mgKOH / g or less, or may be 1.25 mgKOH / g or less. When the above range is satisfied, the solvent resistance can be improved.

[0229] The manufacturing method may include a step of mixing the first biodegradable resin and an inorganic filler to produce a biodegradable resin composition.

[0230] The manufacturing method may include a step of mixing the first biodegradable resin, the inorganic filler, and a second biodegradable resin different from the first biodegradable resin to produce a biodegradable resin composition.

[0231] The second biodegradable resin may be the same as the second biodegradable resin described above.

[0232] The mixing can be appropriately set according to the molding method. For example, before being fed from the hopper into the molding machine, the first and second biodegradable resins and the inorganic filler can be kneaded and melted, and can be molded integrally with the molding machine, and the first and second biodegradable resins and the inorganic filler can also be kneaded and melted. The kneading preferably disperses the inorganic filler uniformly in the first and second biodegradable resins and applies a high shear stress for kneading. Specifically, it is preferably kneaded with a kneader reactor, an extrusion molding machine equipped with a single screw, or a twin-screw kneader. If necessary, one or more of the above-mentioned plasticizers or additives can be further added at this stage.

[0233] The above stage may include one or more mixing stages. In the case of a single mixing stage, based on the total weight of the biodegradable resin composition, the inorganic filler is 60-80 wt%, 61-80 wt%, 62-80 wt%, 63-80 wt%, 64-80 wt%, 65-80 wt%, 60-75 wt%, 61-75 wt%, 62-75 wt%, 63-75 wt%, 64-75 wt%, 65-75 wt%, or 65-72 wt%, and it may be a single mixing stage for producing a biodegradable resin composition. In the case of a two-stage mixing stage, based on the total weight of the biodegradable resin composition, a primary mixing stage for producing a biodegradable resin composition containing the inorganic filler at 60-80 wt%, 61-80 wt%, 62-80 wt%, 63-80 wt%, 64-80 wt%, 65-80 wt%, 60-75 wt%, 61-75 wt%, 62-75 wt%, 63-75 wt%, 64-75 wt%, 65-75 wt%, or 65-72 wt%, and a secondary mixing stage for producing a biodegradable resin composition containing the inorganic filler at 30-85 wt%, 30-80 wt%, 30-75 wt%, 30-70 wt%, 35-85 wt%, 35-80 wt%, 35-75 wt%, 35-70 wt%, 40-85 wt%, 40-80 wt%, 40-75 wt%, 40-70 wt%, 45-85 wt%, 45-80 wt%, 45-75 wt%, 45-70 wt%, 50-85 wt%, 50-80 wt%, 50-75 wt%, or 50-70 wt% based on the total weight of the biodegradable resin composition may be included.

[0234] The above-mentioned one or more mixing stages may be in a tandem continuous process. The temperature of the mixing stage may be 150 - 190°C, 150 - 180°C, or 160 - 180°C. When the above range is satisfied, the phenomenon of increased torque in the mixing stage and the thermal decomposition phenomenon of the mixed biodegradable resin composition can be reduced.

[0235] The manufacturing method may include the step of manufacturing pellets from the biodegradable resin composition.

[0236] In this step, the biodegradable resin composition is put into an extruder equipped with a single screw or an extruder equipped with a twin screw, extruded at a temperature of 150°C - 180°C, cut with a hot-cut type pellet cutter, and cooled at 30°C or lower, 25°C or lower, 5 - 50°C, 10 - 30°C, 15 - 25°C, or 20 - 25°C to manufacture pellets. The cutting step is not particularly limited as long as it is a pellet cutter used in the industry, and the shape of the manufactured pellets is not particularly limited.

[0237] The manufacturing method may include the step of injecting the biodegradable resin composition.

[0238] The biodegradable resin composition may be the pelletized biodegradable resin composition.

[0239] In this step, the pelletized biodegradable resin composition can be manufactured into injection molded products using an injection machine at an injection barrel temperature of 150°C - 250°C, 160°C - 250°C, 160°C - 240°C, or 160°C - 230°C.

[0240] The injection molding may be by injection molding methods such as injection compression molding, injection press molding, gas assist injection molding, foam molding, insert molding, in-mold coating molding, adiabatic mold molding, rapid heating and cooling mold molding, two-color molding, sandwich molding, and ultra-high speed injection molding.

[0241] Hereinafter, based on examples and comparative examples, the present invention will be described more specifically. However, the following examples and comparative examples are only examples for explaining the present invention in more detail, and the present invention is not limited by the following examples and comparative examples.

[0242] Production Example Production Examples of Nanocellulose Dry powder cellulose nanocrystals (NVC-100, manufacturer: Celluforce) having a particle size of about 1 μm to about 50 μm were dispersed in water at 1% by weight, and then ultrasonic treatment was performed for 2 minutes at an output of 20,000 J / s using a tip-type ultrasonic disperser to produce nanocellulose.

[0243] Production Example 1 - First stage: Obtaining a prepolymer 1,4-butanediol (1,4-BDO) and terephthalic acid (TPA) were charged into a 5 kg-sized esterification reaction tank equipped with a nitrogen inlet and a stirrer to produce a slurry. At this time, the molar ratio of the 1,4-butanediol (1,4-BDO) and terephthalic acid (TPA) was 1.4:1, and the D 50 of the terephthalic acid (TPA) was 130 μm.

[0244] The slurry was charged into a reactor through a supply line, and 250 ppm of tetrabutyl titanate (Dupont, Tyzor TnBT product), which is a titanium-based catalyst, was added. Then, the temperature of the slurry was raised to 210 °C, and an esterification reaction was carried out until by-product water was discharged by about 90% or more to produce a first prepolymer.

[0245] Based on the total molar amount of the diol component, 53 mol% of 1,4-butanediol (1,4-BDO) was introduced into the primary esterification reaction product. Based on the total molar amount of the dicarboxylic acid component, 53 mol% of adipic acid (AA) was introduced. Based on the total weight of the diol component and the dicarboxylic acid component, 200 ppm of tetrabutyl titanate (a titanium-based catalyst, product of Dupont, Tyzor TnBT) was introduced. Also, 100 ppm of nanocellulose prepared according to the said production example was introduced into the primary esterification product. Thereafter, at 220 °C and atmospheric pressure, a secondary esterification reaction was carried out for about 2 hours and 30 minutes until 95% of the by-product water was discharged, to produce a second prepolymer having a number average molecular weight of 5,500 g / mol.

[0246] - Second stage: polycondensation reaction The second prepolymer was transferred to a polycondensation reaction vessel with a size of 5 kg. Based on the total weight of the second prepolymer, 150 ppm of tetrabutyl titanate (a titanium-based catalyst, product of Dupont, Tyzor TnBT) and 500 ppm of triethylene phosphate stabilizer were introduced, and then it was stabilized for about 10 minutes.

[0247] Thereafter, after raising the temperature to 240 °C, a polycondensation reaction was carried out at 0.5 torr for 2 hours to produce a PBAT resin having a number average molecular weight of about 42,000 g / mol and a glass transition temperature (Tg) of -30 °C.

[0248] Production Example 2 In Production Example 1, except that 120 ppm of nanocellulose was introduced instead of 100 ppm of nanocellulose and the polycondensation reaction was carried out for 1 hour and 30 minutes instead of 2 hours, a PBAT resin having a number average molecular weight of about 25,000 g / mol and a glass transition temperature (Tg) of -35 °C was produced by the same process as in Production Example 1.

[0249] Example - First biodegradable resin #1: Production Example 1 - First biodegradable resin #2: Production Example 2 - First biodegradable resin #3: Kingfa PBAT, Tg -30°C - Second biodegradable resin: polylactic acid (content of poly D-lactic acid is about 1%, Tg 60°C) - Calcium carbonate #1: Omya - Calcium carbonate #2: Heavy calcium carbonate surface-treated with stearic acid (average particle size (D 50 ) about 3μm) - Chain extender: BASF Joncryl - Lubricant #1: Calcium stearate - Lubricant #2: Stearyl stearate - Antioxidant #1: Phenolic antioxidant, Adeka Korea AO-60 - Antioxidant #2: Phosphorus-based antioxidant, Adeka Korea 2112

[0250] Example 1 In a kneader, the first biodegradable resin #1, calcium carbonate #1, chain extender, antioxidant #1, and antioxidant #2 were mixed at a weight ratio of 52:47:0.2:0.4:0.4 to produce a biodegradable resin composition.

[0251] Examples 2 - 8 and Comparative Examples 1 - 2 Biodegradable resin compositions were produced according to the compositions described in Table 1 below.

[0252]

Table 1

[0253] Experimental Example <Production of biodegradable resin pellets> Each of the biodegradable resin compositions of Examples 1 - 8 and Comparative Examples 1 - 2 was kneaded at a temperature of about 170°C using twin-screw extrusion equipment, and then cut and cooled to produce pelletized biodegradable resin compositions.

[0254] <Production of biodegradable resin specimens> The biodegradable resin pellets of Examples 1 to 8 and Comparative Examples 1 and 2 were each placed between a pair of molds having a size of 60 mm in the lateral direction and 60 mm in the longitudinal direction. Thereafter, under the temperature condition of 180 °C and the pressure condition of 20 MPa, a biodegradable resin test piece having an average thickness of 2 mm was produced.

[0255] <Manufacture of Samples of Biodegradable Resin Test Pieces> The biodegradable resin test piece was cut into a size of 20 mm in the lateral direction, 4 mm in the longitudinal direction, and 0.7 mm in thickness to produce a sample of the biodegradable resin test piece.

[0256] Experimental Example 1 - Mold Shrinkage The volume change when the biodegradable resin compositions of Examples 1 to 8 and Comparative Examples 1 and 2 were produced into biodegradable molded articles by an injection process was evaluated. For the shrinkage rate stability evaluation, after the biodegradable resin test piece was removed from the mold, the shrinkage rate of the biodegradable resin test piece after 24 hours was calculated. Specifically, the lateral shrinkage rate, longitudinal shrinkage rate, and mold shrinkage rate for each of the biodegradable resin test pieces produced in Examples 1 to 8 and Comparative Examples 1 and 2 were measured according to the following Formulas 1 to 3, and the results are shown in Table 2 below.

[0257] [Formula 1] Mold shrinkage rate (%) of biodegradable resin test piece = (Lateral shrinkage rate + Longitudinal shrinkage rate) / 2

[0258] In Formula 1 above, the lateral shrinkage rate is calculated according to Formula 2 below, and the longitudinal shrinkage rate is calculated according to Formula 3 below.

[0259] [Formula 2] Lateral shrinkage rate (%) = (Length of the biodegradable resin test piece in the lateral direction (mm) after 24 hours / 60 mm) × 100

[0260] [Formula 3] Longitudinal shrinkage rate (%) = (Length of the biodegradable resin test piece in the longitudinal direction (mm) after 24 hours / 60 mm) × 100

[0261] Experimental Example 2 - Coefficient of Thermal Expansion For the biodegradable resin compositions of Examples 1 to 8 and Comparative Examples 1 and 2, the dimensional stability at room temperature and the dimensional stability at high temperature when produced into biodegradable molded articles by an injection process were evaluated.

[0262] The dimensional stability evaluation was carried out by measuring the first coefficient of thermal expansion in the range of 10°C to 40°C and the second coefficient of thermal expansion in the range of 80°C to 100°C for each sample of the biodegradable resin specimens of Examples 1 to 8 and Comparative Examples 1 and 2 under the following conditions, and the results are shown in Table 2 below.

[0263] - Analytical equipment: TMA (Thermomechanical Analysis), Q400 from TA Instruments - Test method: ASTM E831 - Measurement mode: Tension mode - Heating rate: 5°C / min - Load: 0.05 N - Atmosphere: N 2 , Flow rate (50 mL / min) - Measurement temperature range: 0°C to 100°C

[0264] Experimental Example 3 - Specific Gravity For each of the biodegradable resin pellets of Examples 1 to 8 and Comparative Examples 1 and 2, the specific gravity was measured at 23°C according to ASTM D792, and the results are shown in Table 2 below.

[0265] Experimental Example 4 - Tensile Strength and Elongation at break For each of the biodegradable resin compositions of Examples 1 to 8 and Comparative Examples 1 and 2, the tensile strength and the elongation at break were measured according to ASTM D638, and the results are shown in Table 2 below.

[0266] Experimental Example 5 - Flexural Strength and Flexural Modulus For each of the biodegradable resin compositions of Examples 1 to 8 and Comparative Examples 1 and 2, the flexural strength and flexural modulus were measured in accordance with ASTM D790, and the results are shown in Table 2 below.

[0267] Experimental Example 6 - Impact Strength For each of the biodegradable resin compositions of Examples 1 to 8 and Comparative Examples 1 and 2, the tensile strength and elongation at break were measured in accordance with ASTM D256, and the results are shown in Table 2 below.

[0268] Experimental Example 7 - Degree of Biodegradation An inoculum source container containing only compost manufactured in accordance with the ISO 14855 standard was prepared, and a test container was prepared in which samples of the dry weight of the compost and the biodegradable resin specimens of Examples 1 to 8 and Comparative Examples 1 and 2 were each introduced onto the compost at a ratio of 6:1. Then, under the conditions of a temperature of 60°C, a humidity of 90%, and an oxygen concentration of 6% or more, the samples were cultured for 180 days. After collecting the carbon dioxide generated in each test container, it was titrated with an aqueous phenolphthalein solution to measure the amount of carbon dioxide generated. The degree of biodegradation was calculated by the following formula 4, and the results are shown in Table 2.

[0269] [Formula 4] Degree of biodegradation (%) = [(Amount of carbon dioxide generated in the test container) - (Amount of carbon dioxide generated in the inoculum source container)] / (Theoretical amount of carbon dioxide generated in the test container) × 100

[0270]

Table 2

[0271] As can be confirmed from Tables 1 and 2 above, Examples 1 to 8, which contain a diol, a biodegradable resin containing an aromatic dicarboxylic acid and an aliphatic dicarboxylic acid, and an inorganic filler and have a mold shrinkage rate of 1.0% or less, were confirmed to be superior in shrinkage rate and dimensional stability at normal temperature and high temperature compared to Comparative Examples 1 and 2. Further, Examples 1 to 8 have a higher specific gravity compared to Comparative Examples 1 and 2, can be suitably used for products that require storage functions, durability, etc., and were confirmed to be excellent in flexural strength and flexural modulus. Also, Examples 1 to 8 were confirmed to be superior in elongation at break and impact strength compared to Comparative Example 2, with improved brittleness and improved processability.

Claims

1. A first biodegradable resin having a glass transition temperature (Tg) of −15° C. or lower; An inorganic filler; Including, The mold shrinkage rate of the biodegradable resin specimen measured by the following measurement method 1 is 1.0% or less. Biodegradable resin composition. [Measurement method 1] 1) The biodegradable resin composition is placed between a pair of molds having a size of 60 mm in the horizontal direction and 60 mm in the vertical direction, and then a biodegradable resin specimen having an average thickness of 2 mm is manufactured under conditions of a temperature of 180° C. and a pressure of 20 MPa. 2) The biodegradable resin specimen is removed from the mold, and the transverse and longitudinal shrinkage rates of the biodegradable resin specimen are calculated after 24 hours. 3) Calculate the mold shrinkage of the biodegradable resin specimen according to the following formula 1. [Formula 1] Mold shrinkage rate of biodegradable resin specimen (%) = (transverse shrinkage rate + longitudinal shrinkage rate) / 2 In the formula 1, the shrinkage rate in the horizontal direction is calculated by the following formula 2, and the shrinkage rate in the vertical direction is calculated by the following formula 3. [Formula 2] Shrinkage rate in horizontal direction (%)=(length in horizontal direction of the biodegradable resin specimen after 24 hours (mm) / 60 mm)×100 [Formula 3] Shrinkage rate in the longitudinal direction (%)=(length in the longitudinal direction of the biodegradable resin specimen after 24 hours (mm) / 60 mm)×100

2. The mold shrinkage rate of the biodegradable resin specimen is 0.5% or less; The biodegradable resin composition according to claim 1.

3. The content of the inorganic filler is 10% by weight to 90% by weight based on the total weight of the biodegradable resin composition. The biodegradable resin composition according to claim 1.

4. The biodegradable resin composition contains the first biodegradable resin and the inorganic filler in a weight ratio of 90:10 to 30:

70. The biodegradable resin composition according to claim 1.

5. The biodegradable resin composition includes a second biodegradable resin different from the first biodegradable resin, and the second biodegradable resin has a glass transition temperature (Tg) of 50° C. or higher. The biodegradable resin composition according to claim 1.

6. The second biodegradable resin has a flexural strength of 50 MPa or more according to ASTM D790. The biodegradable resin composition according to claim 5.

7. The second biodegradable resin has a flexural modulus according to ASTM D790 of 2,500 MPa or more. The biodegradable resin composition according to claim 5.

8. The biodegradable resin composition contains the first biodegradable resin:the second biodegradable resin in a weight ratio of 90:10 to 10:

90. The biodegradable resin composition according to claim 5.

9. The first thermal expansion coefficient of the sample of the biodegradable resin specimen measured by the following Measurement Method 2 is 75 μm / (m·° C.) to 290 μm / (m·° C.); The biodegradable resin composition according to claim 1. [Measurement method 2] 1) The biodegradable resin specimen is cut into a size of 20 mm in width, 4 mm in length, and 0.7 mm in thickness to prepare a sample of the biodegradable resin specimen. 2) The biodegradable resin specimen sample is heated from 0° C. to 100° C. at a rate of 5° C. / min using a thermomechanical analyzer, and a first thermal expansion coefficient is measured in the range of 10° C. to 40° C.

10. The sample of the biodegradable resin specimen has a second thermal expansion coefficient of 100 μm / (m·°C) to 1,000 μm / (m·°C) in the range of 80°C to 100°C measured by the measurement method 2. The biodegradable resin composition according to claim 9.

11. The specific gravity of the biodegradable resin pellets is 1.30 to 2.00 as measured by the following Measurement Method 3. The biodegradable resin composition according to claim 1. [Measurement method 3] 1) The biodegradable resin composition is extruded at 175° C. and then cooled at 5° C. to produce biodegradable resin pellets. 2) Measure the specific gravity of the biodegradable resin pellets at 23° C. in accordance with ASTM D792.

12. A first biodegradable resin having a glass transition temperature (Tg) of −15° C. or lower; An inorganic filler; Including, A biodegradable molded article comprising a biodegradable resin composition, the mold shrinkage rate of a biodegradable resin specimen being 1.0% or less as measured by the following Measurement Method 1. [Measurement method 1] 1) The biodegradable resin composition is placed between a pair of molds each having a size of 60 mm in the horizontal direction x 60 mm in the vertical direction, and then a biodegradable resin specimen having an average thickness of 2 mm is manufactured under conditions of a temperature of 180°C and a pressure of 20 MPa. 2) The biodegradable resin specimen is removed from the mold, and the transverse and longitudinal shrinkage rates of the biodegradable resin specimen are calculated after 24 hours. 3) Calculate the mold shrinkage of the biodegradable resin specimen according to the following formula 1. [Formula 1] Mold shrinkage rate of biodegradable resin specimen (%) = (transverse shrinkage rate + longitudinal shrinkage rate) / 2 In the formula 1, the shrinkage rate in the horizontal direction is calculated by the following formula 2, and the shrinkage rate in the vertical direction is calculated by the following formula 3. [Formula 2] Shrinkage rate in horizontal direction (%)=(length in horizontal direction of the biodegradable resin specimen after 24 hours (mm) / 60 mm)×100 [Formula 3] Shrinkage rate in the longitudinal direction (%)=(length in the longitudinal direction of the biodegradable resin specimen after 24 hours (mm) / 60 mm)×100

13. The biodegradable molded article is a nonwoven fabric, a vacuum-formed sheet, a blown molded article, or an injection molded article; The biodegradable molded article according to claim 12.

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