Method for preparing biodegradable resin composition

Abstract

The present invention relates to a method for preparing a biodegradable resin composition using an isocyanate compound as a compatibilizing agent, and a biodegradable resin composition and a biodegradable film having, due to the method, a decreased rate of dissolution in water and thus improved durability and mechanical properties.

Description

Method for producing a biodegradable resin composition

[0001] The present invention relates to a method for producing a biodegradable resin composition having improved leaching characteristics by introducing an isocyanate compound to induce a urethane bond, and to a biodegradable resin composition and biodegradable film having improved durability and mechanical properties thereby.

[0002] Biodegradable polymers can be categorized into petroleum-derived and bio-derived, with relatively high interest in eco-friendly and renewable bio-derived polymers. Polymers that are fully biodegradable in the global environment contain functional groups in their backbone structure that enable microbial decomposition. Among these, polyester polymers are the most widely studied due to their excellent processability and easy control of biodegradation properties. For example, polylactic acid (PLA) is a bio-derived biodegradable polymer synthesized from lactic acid, obtained by fermenting corn starch. It has a global market size of approximately 100,000 tons and is widely used in general plastic applications such as food packaging and containers, and electronic device cases. However, PLA resins have poor formability, mechanical strength, and heat resistance, making thin-film products susceptible to breakage. Furthermore, their low temperature resistance can cause deformation of the molded product when the external temperature increases.

[0003] In addition, polybutylene adipate-co-terephthalate (PBAT), the most widely used petroleum-derived biodegradable polyester polymer, is a copolymer resin containing aliphatic and aromatic groups. Although it has relatively excellent mechanical properties and various processability, it has the disadvantages of low structural strength and high manufacturing cost. In order to improve the low physical properties of the above-mentioned polyester resin and reduce the high manufacturing cost compared to the manufacturing cost of non-biodegradable polymers, various research methods are being proposed to make composite materials by including biomass, an eco-friendly material.

[0004] Accordingly, research has been conducted to reduce costs and improve biodegradability by incorporating starch, a representative plant-based biomass, into biodegradable resins. However, the application of starch to biodegradable resins has generally been limited by its inherent hydrophilicity and reduced processability, resulting in deteriorated physical properties. This limits the amount of starch added, and can lead to lower product quality.

[0005] To address these issues, various attempts have been made to impart thermoplastic properties to starch by reacting it with plasticizers and then blending it with biodegradable resins to produce composite materials. However, these methods have yet to meet industrial standards. Therefore, there is a pressing need for the development of eco-friendly materials that simultaneously satisfy biodegradability, mechanical properties, and economic feasibility.

[0006] The purpose of the present invention is to provide a method for producing a biodegradable resin composition capable of reducing the water leaching rate by producing a biomass composite using an isocyanate compound as a compatibilizer in a biodegradable resin composition containing starch.

[0007] One aspect of the present invention provides a method for producing a biodegradable resin composition, comprising the steps of mixing and reacting starch, a plasticizer, a first compatibilizer, and a second compatibilizer to produce a biomass composite, and mixing the biomass composite with a biodegradable resin, wherein the first compatibilizer is at least one selected from a carboxylic anhydride and a carboxylic acid, and the second compatibilizer is an isocyanate compound. The method for producing a biodegradable resin composition may further include a reaction initiator, if necessary.

[0008] According to an embodiment, the first commercializing agent may be at least one selected from the group consisting of maleic anhydride, succinic anhydride, glutaric anhydride, dimethylmaleic anhydride, malonic acid, succinic acid, glutamic acid, citric acid, and tartaric acid, but is not limited thereto.

[0009] According to an embodiment, the second commercializing agent may be at least one selected from the group consisting of pentamethylene diisocyanate, isophorone diisocyanate, xylene diisocyanate, naphthalene diisocyanate, and 6-methyl-2-heptane isocyanate, but is not limited thereto.

[0010] The first compatibilizer may be maleic anhydride, and the second compatibilizer may be pentamethylene diisocyanate.

[0011] According to an embodiment, the plasticizer may be at least one selected from the group consisting of glycerin, ethylene glycol, sorbitol, and pentaerythritol, but is not limited thereto.

[0012] According to an embodiment, based on the total weight of the biomass composite, the content of the starch may be 70 to 90 wt%, the content of the plasticizer may be 5 to 30 wt%, the content of the first compatibilizer may be 0.1 to 1.0 wt%, and the content of the second compatibilizer may be 0.1 to 1.0 wt%.

[0013] According to an embodiment, the biomass composite may comprise 20 to 40 wt% and the second biodegradable resin may comprise 60 to 80 wt%.

[0014] According to an embodiment, the starch usable in the biodegradable resin composition may be at least one selected from the group consisting of corn starch, waxy corn starch, rice starch, potato starch, tapioca starch, wheat starch, sweet potato starch, or modified starches thereof, but is not limited thereto.

[0015] According to an embodiment, the biodegradable resin usable in the biodegradable resin composition may be, but is not limited to, one or more independently selected from the group consisting of polybutylene adipate terephthalate, polylactic acid, polycaprolactone, polybutylene succinate, polyglycolic acid, polyhydroxyalkanoate, polyhydroxybutyrate, copolymers thereof, and mixtures thereof.

[0016] In an embodiment, the step of manufacturing a biomass composite may further include a step of extruding the biomass composite into pellets.

[0017] Another aspect of the present invention provides a biodegradable resin composition manufactured by the above manufacturing method.

[0018] Another aspect of the present invention provides a biodegradable film manufactured using the biodegradable resin composition.

[0019] The water solubility of the biodegradable resin composition (compound) according to the embodiment may be 3% or less, and the melt flow viscosity (g / 10 min, 190) may be in the range of 1.0 to 7.0.

[0020] According to the present invention, when a biodegradable resin composition based on a starch biomass composite is manufactured using an isocyanate compound as a compatibilizer together with a plasticizer, a urethane bond is formed between the -OH group of the starch and the isocyanate group, and since the urethane bond is a stronger chemical bond than a hydrogen bond or an ester bond, there is an effect of reducing the phenomenon of water soaking and leaching of the plasticizer, etc., in the biodegradable composite material.

[0021] In this way, by forming a new network between molecules through chemical bonding with starch, the processability and water solubility of biodegradable composite materials can be improved.

[0022] The present invention will be described in more detail below with reference to examples. However, the following examples are provided for illustrative purposes only to aid understanding of the present invention and are not intended to limit its scope. It should be understood that the present invention is susceptible to various modifications and implementations in various different forms, and encompasses all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention.

[0023] Additionally, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0024] A method for producing a biodegradable resin composition according to one embodiment of the present invention comprises the steps of i) mixing and reacting starch, a plasticizer, a first compatibilizer, and a second compatibilizer to produce a biomass composite, and ii) mixing the biomass composite with a biodegradable resin, wherein the first compatibilizer is at least one selected from a carboxylic anhydride and a carboxylic acid, and the second compatibilizer is an isocyanate compound. The method for producing a biodegradable resin composition may further include a reaction initiator, if necessary.

[0025] According to one embodiment of the present invention, the content of the starch may be 70 to 90 wt%, the content of the plasticizer may be 5 to 30 wt%, the content of the first compatibilizer may be 0.1 to 1.0 wt%, and the content of the second compatibilizer may be 0.1 to 1.0 wt%.

[0026] The starch that can be used in the manufacture of the biomass composite (thermoplastic starch composition) may be at least one selected from the group consisting of corn starch, waxy corn starch, rice starch, potato starch, tapioca starch, wheat starch, sweet potato starch, or modified starches thereof, but is not limited thereto. When starch is used in an amount of less than 70 wt% in the biomass composite (thermoplastic starch composition), raw materials other than starch may be used in excess, which increases the cost and is not economical. When starch is used in an amount of more than 90 wt%, some unplasticized starch may remain, which may cause a deterioration in physical properties when manufacturing a thermoplastic starch and a biodegradable composite resin.

[0027] The plasticizer usable in the production of a biomass composite (thermoplastic starch composition) may be one or more selected from the group consisting of glycerin, ethylene glycol, sorbitol, and pentaerythritol, but is not limited thereto. It is preferable to use the plasticizer in an amount of 1 to 30 wt% based on the total weight of the biomass composite. If the content of the plasticizer is less than the above range, a plasticization reaction does not occur, and if it exceeds the content, excessive plasticization occurs, resulting in a problem of a paste-like state.

[0028] The first compatibilizer usable in the production of a biomass composite (thermoplastic starch composition) may be at least one selected from carboxylic anhydrides and carboxylic acids. For example, the first compatibilizer may be at least one selected from maleic anhydride, succinic anhydride, glutaric anhydride, dimethylmaleic anhydride, malonic acid, succinic acid, glutamic acid, citric acid, and tartaric acid.

[0029] The second compatibilizer usable in the production of the biomass composite (thermoplastic starch composition) may be an isocyanate compound. For example, one or more compounds selected from the group consisting of pentamethylene diisocyanate, isophorone diisocyanate, xylene diisocyanate, naphthalene diisocyanate, and 6-methyl-2-heptane isocyanate may be mentioned.

[0030] According to one embodiment of the present invention, it is preferable that the first compatibilizer is maleic anhydride and the second compatibilizer is pentamethylene diisocyanate.

[0031] Introducing an isocyanate compound as a compatibilizer forms a urethane bond between the -OH group and the isocyanate group of the starch. Because the urethane bond is a stronger chemical bond than hydrogen or ester bonds, it has the effect of reducing water-leaching in biodegradable composite materials. Similarly, using maleic anhydride and an isocyanate compound as compatibilizers together can further reduce the film's water-leaching rate, thereby improving its durability.

[0032] Among the biomass composite (thermoplastic starch composition), the first compatibilizer and the second compatibilizer can each be independently used in the range of 0.1 to 1.0 wt%, and it is preferable to use them in the range of 0.1 to 0.5 wt%, respectively.

[0033] In addition, the present invention can also produce a biomass composite (thermoplastic starch composition) by pre-mixing a small amount of a first biodegradable resin in the range of 2 to 5 wt% as well as an isocyanate compatibilizer.

[0034] Additionally, according to an embodiment, a reaction initiator may be used in the production of a biomass composite. Usable reaction initiators include, for example, one selected from the group consisting of benzoyl peroxide, acetyl peroxide, dilauryl peroxide, di-t-butyl peroxide, cumyl peroxide, di-t-butyl hydroperoxide, dibenzoyl peroxide, succinic peroxide, dilaurylyl peroxide, didecanoyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, α-cumyl peroxyneodecarbonate, 1,1-dimethyl-3-hydroxybutylperoxy-2-ethylhexanoate, t-amyl peroxybenzoate, t-butyl peroxypivalate, 2,5-dihydroxyperoxy-2,5-dimethylhexane, cumene hydroperoxide or 1,3-bis(t-butylperoxyisopropyl)benzene. The above peroxide-based reaction initiator may be used, but is not limited thereto. It is preferable to use the reaction initiator in an amount of 0.01 to 1.0 wt% based on the total weight of the biomass composite.

[0035] In the present invention, the biomass composite (thermoplastic starch composition) can be manufactured into pellets by extruding using a twin-screw extruder or the like, which is preferable because it provides convenience in processing or manufacturing products by mixing with a biodegradable resin.

[0036] According to one embodiment of the present invention, a biodegradable resin composition is prepared by mixing a biomass composite containing starch and then mixing the biodegradable resin. The biodegradable resin composition can be prepared by mixing 20 to 40 wt% of the biomass composite and 60 to 80 wt% of the biodegradable resin at a mixing ratio.

[0037] The biodegradable resin to be mixed with the biomass composite (thermoplastic starch composition) may be selected from the group consisting of, but is not limited to, one or more of polybutylene adipate terephthalate (PBAT), polylactic acid (PLA), polybutylene succinate (PBS), polycaprolactone (PCL), polyglycolic acid (PGA), polyhydroxy alkanoate (PHA), polyhydroxybutyrate (PHB), copolymers thereof, and mixtures thereof.

[0038] The biodegradable resin composition may further include a process of mixing a biomass composite and a biodegradable resin, extruding the mixture to form pellets, and then feeding the mixture into a film forming machine to form a biodegradable film.

[0039] According to one embodiment of the present invention, a biodegradable film can be manufactured using the biodegradable resin composition. The biodegradable film manufactured using the biodegradable resin composition according to the present invention has the advantages of excellent biodegradability and mechanical properties, as well as improved water immersion rate.

[0040] According to an embodiment, a biodegradable resin composition containing an isocyanate compound forms a chemical bond with starch to form a new network between molecules, thereby improving the processability and water solubility of the biodegradable composite material.

[0041] The water immersion dissolution rate measured after immersion for 24 hours at room temperature of a compound manufactured using a biodegradable resin composition according to an embodiment may be 3% or less, and the melt flow viscosity (g / 10 min, 190°C) may be 1.0 to 7.0. When thermoplastic starch is manufactured, it is judged that the molecular weight of the thermoplastic starch increases due to the bonding of the starch or the composition itself through intermolecular interaction and chemical reaction between thermoplastic starch compositions, thereby reducing the melt flow characteristics of the thermoplastic starch.

[0042] In this way, a biodegradable film manufactured using a biodegradable resin composition containing an isocyanate compound has excellent durability due to improved water solubility, and thus can be used in various products such as disposable bags, disposable packaging materials, tablecloths, and mulching films.

[0043] The present invention is described in more detail below through examples and comparative examples, but these are illustrative and should not be construed as limiting the scope of the present invention.

[0044] <Example 1>

[0045] A) Manufacturing of biomass composite (thermoplastic starch composition)

[0046] 85 parts by weight of corn starch and 15 parts by weight of glycerin were mixed and placed in a heating mixer, and 0.5% by weight of PDI (pentamethylene diisocyanate) was added based on the weight of the mixture. High-speed mixing was performed using a shovel mixer.

[0047] The uniformly mixed composition was fed into a twin-screw extruder. The extruder barrel temperature was 140°C to 145°C, and the main screw speed was 300 rpm. The extrudate was pelletized to produce a biomass composite (thermoplastic starch composition).

[0048] B) Preparation of biodegradable resin composition

[0049] 40 parts by weight of the above biomass composite and 60 parts by weight of PBAT were mixed. The uniformly mixed composition was fed into a twin-screw extruder. The extruder barrel temperature was 170°C, and the main screw speed was 290 rpm. The extrudate discharged through the extruder die was water-cooled and pelletized through a water channel. The pellets were dried at 60°C for more than 24 hours to prepare a biodegradable resin composition for film.

[0050] C) Manufacturing of biodegradable composite material property specimens

[0051] The above biodegradable resin composition was placed into a material specimen making machine to produce a mold specimen. The temperature set in the material specimen making machine was 205°C.

[0052] D) Manufacturing of biodegradable films

[0053] The above biodegradable composition was fed into a film forming machine to produce a biodegradable film with an average thickness of 25-35㎛. The film forming machine temperature was 150 to 170℃, and the raw material feeding speed was 700 to 800 rpm.

[0054] <Example 2>

[0055] A) Biomass composite manufacturing

[0056] 85 parts by weight of corn starch and 15 parts by weight of glycerin were mixed and placed in a heating mixer, and then 0.1% by weight of maleic anhydride and 0.5% by weight of PDI (pentamethylene diisocyanate) were added based on the weight of the mixture. High-speed mixing was performed using a shovel mixer.

[0057] The uniformly mixed composition was fed into a twin-screw extruder. The extruder barrel temperature was 140°C to 145°C, and the main screw speed was 300 rpm. The extrudate was pelletized to produce a biomass composite (thermoplastic starch composition).

[0058] B) Preparation of a biodegradable resin composition, C) Preparation of a biodegradable composite material property specimen, and D) Preparation of a biodegradable film are the same as in Example 1.

[0059] <Example 3>

[0060] A) Biomass composite manufacturing

[0061] 85 parts by weight of corn starch and 15 parts by weight of glycerin were mixed and placed in a heating mixer, and then 0.2% by weight of maleic anhydride and 0.3% by weight of PDI (pentamethylene diisocyanate) were added based on the weight of the mixture. High-speed mixing was performed using a shovel mixer.

[0062] The uniformly mixed composition was fed into a twin-screw extruder. The extruder barrel temperature was 140°C to 145°C, and the main screw speed was 300 rpm. The extrudate was pelletized to produce a biomass composite (thermoplastic starch composition).

[0063] B) Preparation of a biodegradable resin composition, C) Preparation of a biodegradable composite material property specimen, and D) Preparation of a biodegradable film are the same as in Example 1.

[0064] <Example 4>

[0065] A) Biomass composite manufacturing

[0066] 85 parts by weight of corn starch and 15 parts by weight of glycerin were mixed and placed in a heating mixer, and then 0.3% by weight of maleic anhydride and 0.2% by weight of PDI (pentamethylene diisocyanate) were added based on the weight of the mixture. High-speed mixing was performed using a shovel mixer.

[0067] The uniformly mixed composition was fed into a twin-screw extruder. The extruder barrel temperature was 140°C to 145°C, and the main screw speed was 300 rpm. The extrudate was pelletized to produce a biomass composite (thermoplastic starch composition).

[0068] B) Preparation of a biodegradable resin composition, C) Preparation of a biodegradable composite material property specimen, and D) Preparation of a biodegradable film are the same as in Example 1.

[0069] <Example 5>

[0070] A) Biomass composite manufacturing

[0071] 85 parts by weight of corn starch and 15 parts by weight of glycerin were mixed and placed in a heating mixer, and then 0.5% by weight of maleic anhydride and 0.2% by weight of PDI (pentamethylene diisocyanate) were added based on the weight of the mixture. High-speed mixing was performed using a shovel mixer.

[0072] The uniformly mixed composition was fed into a twin-screw extruder. The extruder barrel temperature was 140°C to 145°C, and the main screw speed was 300 rpm. The extrudate was pelletized to produce a biomass composite (thermoplastic starch composition).

[0073] B) Preparation of a biodegradable resin composition, C) Preparation of a biodegradable composite material property specimen, and D) Preparation of a biodegradable film are the same as in Example 1.

[0074] <Example 6>

[0075] A) Biomass composite manufacturing

[0076] 85 parts by weight of corn starch and 15 parts by weight of glycerin were mixed and placed in a heating mixer, and then 0.5% by weight of maleic anhydride and 0.05% by weight of PDI (pentamethylene diisocyanate) were added based on the weight of the mixture. High-speed mixing was performed using a shovel mixer.

[0077] The uniformly mixed composition was fed into a twin-screw extruder. The extruder barrel temperature was 140°C to 145°C, and the main screw speed was 300 rpm. The extrudate was pelletized to produce a biomass composite (thermoplastic starch composition).

[0078] B) Preparation of a biodegradable resin composition, C) Preparation of a biodegradable composite material property specimen, and D) Preparation of a biodegradable film are the same as in Example 1.

[0079] <Example 7>

[0080] A) Biomass composite manufacturing

[0081] 85 parts by weight of corn starch and 15 parts by weight of glycerin were mixed and placed in a heating mixer, and then 0.5% by weight of maleic anhydride and 0.03% by weight of PDI (pentamethylene diisocyanate) were added based on the weight of the mixture. High-speed mixing was performed using a shovel mixer.

[0082] The uniformly mixed composition was fed into a twin-screw extruder. The extruder barrel temperature was 140°C to 145°C, and the main screw speed was 300 rpm. The extrudate was pelletized to produce a biomass composite (thermoplastic starch composition).

[0083] B) Preparation of a biodegradable resin composition, C) Preparation of a biodegradable composite material property specimen, and D) Preparation of a biodegradable film are the same as in Example 1.

[0084] <Example 8>

[0085] A) Biomass composite manufacturing

[0086] 85 parts by weight of corn starch and 15 parts by weight of glycerin were mixed and placed in a heating mixer, and then 0.5% by weight of maleic anhydride and 0.01% by weight of PDI (pentamethylene diisocyanate) were added based on the weight of the mixture. High-speed mixing was performed using a shovel mixer.

[0087] The uniformly mixed composition was fed into a twin-screw extruder. The extruder barrel temperature was 140°C to 145°C, and the main screw speed was 300 rpm. The extrudate was pelletized to produce a biomass composite (thermoplastic starch composition).

[0088] B) Preparation of a biodegradable resin composition, C) Preparation of a biodegradable composite material property specimen, and D) Preparation of a biodegradable film are the same as in Example 1.

[0089] <Comparative Example 1>

[0090] A) Biomass composite manufacturing

[0091] 85 parts by weight of corn starch and 15 parts by weight of glycerin were mixed and placed in a heating mixer, and then 0.5% by weight of maleic anhydride was added based on the weight of the mixture. High-speed mixing was performed using a shovel mixer.

[0092] The uniformly mixed composition was fed into a twin-screw extruder. The extruder barrel temperature was 140°C to 145°C, and the main screw speed was 300 rpm. The extrudate was pelletized to produce a biomass composite (thermoplastic starch composition).

[0093] B) Preparation of a biodegradable resin composition, C) Preparation of a biodegradable composite material property specimen, and D) Preparation of a biodegradable film are the same as in Example 1.

[0094] <Physical property evaluation>

[0095] The composition of the biomass composites manufactured in the above examples and comparative examples and the water immersion characteristics of the biodegradable resin compositions (compounds) were evaluated as follows, and the results are shown in [Table 1] and [Table 2].

[0096] For the water immersion test, the biodegradable resin compositions manufactured in the examples and comparative examples were used to manufacture compound sheets using a hydraulic hot press, and the manufactured specimens were cut into 5×10 (cm) and tested for water immersion.

[0097] - Hydraulic hot press conditions: Temperature 190 ~ 200℃, pressure 25 bar

[0098] - Immersion dissolution conditions: Room temperature, 450 mL of water, specimen size 5 × 10 (cm), 24-hour dissolution

[0099] After immersion of the sample in water, the weight change before and after extraction was used to evaluate the extraction and HPLC analysis of the extraction solution was performed.

[0100] ClassificationExample 1Example 2Example 3Example 4Example 5Compatibilizer Total content (%) 0.5 0.5 0.5 0.5 0.7CompatibilizerMaleic anhydride 0 0.1 0.2 0.3 0.5PDI 0.5 0.4 0.3 0.2 0.2TPSMFI (g / 10min, 200℃) 0 0.06 0.94 17.7 1 12.5Compound mixingTPS 4 0 4 0 4 0 4 0 4 0PBAT 6 0 6 0 6 0 6 0ResultMFI (g / 10min, 190℃) 2.2 2.4 1.6 0.8 1.8Water immersion elution (%) 1.4 1.1 3.3 7.6 8.3

[0101] ClassificationExample 6Example 7Example 8Comparative Example 1Total content of compatibilizer (%) 0.55 0.53 0.51 0.5CompatibilizerMaleic anhydride 0.5 0.5 0.5 0.5PDI 0.05 0.03 0.01 0.0TPSMFI (g / 10min, 200℃) 27.8 4 1.7 5 1.4 2 1.8Compound mixingTPS 40 40 40 40PBAT 60 60 60 60ResultMFI (g / 10min, 190℃) 1.1 1.4 1.3 1.9Water immersion elution (%) 10.2 10.4 6.13.8

[0102] - TPS (thermoplastic starch composition): 85 parts by weight of starch, 15 parts by weight of plasticizer (glycerin),

[0103] - Compound composition: GTPS 40 wt%, PBAT 60 wt%

[0104] - PDI: 1,5-Pentamethylene Diisocyanat

[0105] As shown in the above table, it can be confirmed that the water immersion dissolution rate of the compounds manufactured using thermoplastic starch containing an appropriate amount of pentamethylene diisocyanate (PDI) according to Examples 1 to 3 was improved. In particular, it can be seen that the water immersion dissolution rate is further improved when maleic anhydride and pentamethylene diisocyanate (PDI) are used together.

Claims

1. A step of manufacturing a biomass composite by mixing and reacting starch, a plasticizer, a first compatibilizer, and a second compatibilizer; and Comprising a step of mixing the above biomass composite and biodegradable resin, A method for producing a biodegradable resin composition, characterized in that the first compatibilizer is at least one selected from a carboxylic anhydride and a carboxylic acid, and the second compatibilizer is an isocyanate compound.

2. In paragraph 1, A method for producing a biodegradable resin composition, wherein the first solubilizing agent is at least one selected from the group consisting of maleic anhydride, succinic anhydride, glutaric anhydride, dimethylmaleic anhydride, malonic acid, succinic acid, glutamic acid, citric acid, and tartaric acid.

3. In paragraph 1, A method for producing a biodegradable resin composition, wherein the second solubilizing agent is at least one selected from the group consisting of pentamethylene diisocyanate, isophorone diisocyanate, xylene diisocyanate, naphthalene diisocyanate, and 6-methyl-2-heptane isocyanate.

4. In paragraph 1, A method for producing a biodegradable resin composition, wherein the starch is at least one selected from the group consisting of corn starch, waxy corn starch, rice starch, potato starch, tapioca starch, wheat starch, sweet potato starch, or modified starches thereof.

5. In paragraph 1, A method for producing a biodegradable resin composition, wherein the plasticizer is at least one selected from the group consisting of glycerin, ethylene glycol, sorbitol, and pentaerythritol.

6. In paragraph 1, A method for producing a biodegradable resin composition, wherein the content of the starch is 70 to 90 wt%, the content of the plasticizer is 5 to 30 wt%, the content of the first compatibilizer is 0.1 to 1.0 wt%, and the content of the second compatibilizer is 0.1 to 1.0 wt%, based on the total weight of the biomass composite.

7. In paragraph 1, A method for producing a biodegradable resin composition comprising 20 to 40 wt% of the biomass composite and 60 to 80 wt% of the second biodegradable resin.

8. A biodegradable resin composition manufactured by the manufacturing method according to Article 1.

9. In paragraph 8, A biodegradable resin composition having a water immersion rate of 3% or less when measured after immersion in water for 24 hours at room temperature.

10. A biodegradable film manufactured using a biodegradable resin composition according to Article 8.