US-12624199-B2 - Biodegradable resin composition and method for producing same

US12624199B2US 12624199 B2US12624199 B2US 12624199B2US-12624199-B2

Abstract

A biodegradable resin composition and a method for producing the biodegradable resin composition are disclosed. The biodegradable resin includes three components, polyethylene, a biodegradable resin, and at least one selected from polybutylene adipate terephthalate and maleic anhydride copolymer, thereby providing excellent compatibility and mechanical properties.

Inventors

Yu Jeong Lim
Yu Jeong JEONG
Jeong Hyun PARK
Jae Kyu JANG

Assignees

Hanwha Solutions Corporation

Dates

Publication Date: 20260512
Application Date: 20201019
Priority Date: 20191205

Claims (13)

1 . A biodegradable resin composition comprising a polyethylene in an amount of 50 wt % to 70 wt %, a biodegradable resin in an amount of 15-30 wt %, and a maleic anhydride copolymer in an amount of 10-30 wt %, each based on a total weight of the biodegradable resin composition, wherein the maleic anhydride copolymer is a copolymer of maleic anhydride with at least one selected from polybutylene adipate terephthalate (PBAT), polybutylene succinate adipate (PBSA), and polybutylene succinate (PBS).
2 . The biodegradable resin composition of claim 1 , wherein the polyethylene comprises at least one selected from high density polyethylene (HDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), linear low density polyethylene (LLDPE), and ethylene-vinyl acetate copolymer (EVA).
3 . The biodegradable resin composition of claim 1 , wherein the biodegradable resin comprises at least one selected from thermoplastic starch (TPS), polylactic acid (PLA), polycaprolactone (PCL), polybutylene succinate (PBS), polyglycolic acid (PGA), polyhydroxyalkanoate (PHA), polyhydroxybutyrate (PHB), cellulose, and chitin.
4 . The biodegradable resin composition of claim 3 , wherein the thermoplastic starch comprises at least one selected from rice starch, wheat starch, corn starch, sweet potato starch, potato starch, tapioca starch, cassava starch, and modified starches thereof.
5 . The biodegradable resin composition of claim 1 , wherein the polyethylene has a weight average molecular weight of 100,000 to 300,000.
6 . The biodegradable resin composition of claim 1 , wherein a melting temperature of the biodegradable resin composition is 100° C. to 130° C., and a melt index of the biodegradable resin composition is 0.01-10 g/10 min at 2.16 kg at 190° C. based on ASTM D1238.
7 . A biodegradable film comprising the biodegradable resin composition according to claim 1 .
8 . The biodegradable film of claim 7 , wherein the film is applicable to at least one selected from industrial films, food films, agricultural films, and daily life films.
9 . The biodegradable film of claim 7 , wherein the film has a thickness of 1-50 μm.
10 . A method for producing a biodegradable resin composition, said biodegradable resin composition comprising a polyethylene in an amount of 50 wt % to 70 wt %, a biodegradable resin in an amount of 15-30 wt %, and a maleic anhydride copolymer in an amount of 10-30 wt %, each based on a total weight of the biodegradable resin composition, wherein the maleic anhydride copolymer is a copolymer of maleic anhydride with at least one selected from polybutylene adipate terephthalate (PBAT), polybutylene succinate adipate (PBSA), and polybutylene succinate (PBS), the method comprising: providing a mixture of the polyethylene, the biodegradable resin, and the maleic anhydride copolymer, and subject to the mixture melt blending to produce the biodegradable resin composition.
11 . The method of claim 10 , wherein the melt blending is carried out at 160° C. to 210° C.
12 . The method of claim 10 , wherein the melt blending uses at least one selected from an extruder, a kneader, a Brabender Plasticorder, a mixing roll, and a mixer.
13 . The method of claim 12 , wherein the extruder uses one or more selected from a single-screw extruder, a twin-screw extruder, and a single-screw and twin-screw extruder.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a National Stage of International Application No. PCT/KR2020/014258 filed Oct. 19, 2020, claiming priority based on Korean Patent Application No. 10-2019-0160636 filed Dec. 5, 2019. TECHNICAL FIELD The present invention relates to a biodegradable resin composition and a method for producing the same, and more particularly, to a technique for providing a biodegradable resin including three components, polyethylene, a biodegradable resin, and at least one selected from polybutylene adipate terephthalate and maleic anhydride copolymer, thereby providing excellent compatibility and mechanical properties. BACKGROUND ART Since plastic has excellent physical properties and cheap and light characteristics, various polymers have been developed centering on plastic beyond the limits of natural materials to built a modern scientific civilization. Plastic is characterized by being strong, light and tough and not easily decomposing. Due to these properties, plastic is used in various ways from industrial materials to disposable materials. Research has been conducted for a long time to further improve the toughness and durability of synthetic resins such as plastic, and these efforts are still ongoing. However, environmental pollution caused by plastic waste that is getting serious is a problem. For example, due to the detection of highly toxic dioxins, the leakage of environmental hormones, and the like, not only the social demand for eco-friendly plastic but also the standards of each country's legal regulations on the use of non-degradable plastic are getting stronger. In order to solve this problem, the development of biodegradable polymers is being treated as a very important matter, and is attracting attention as an important field in the plastic industry. In general, according to the American Society for Testing and Materials (ASTM), degradable plastic refers to plastic whose chemical structure is significantly changed for a certain period of time under specific environmental conditions, so that the change in properties may be measured by standard test methods. Degradable plastic may be divided into photodegradable plastic, biodestructible plastic, and biodegradable plastic. More specifically, photodegradable plastic refers to plastic that is decomposed by light in the form of photooxidation or ketone photolysis. However, since photodegradable plastic is decomposed by light, there is a disadvantage in that photodegradable plastic is not decomposed when buried in the ground where light is blocked. Biodestructible plastic refers to partially degradable plastic produced by adding a certain amount of biodegradable material such as starch to non-degradable general-purpose resin (polyethylene, polypropylene, etc.). In Korea, in order to avoid confusion with biodegradable plastic, the term “biodestructible plastic” is used to distinguish from biodegradable plastic. Biodegradable plastic generally refers to plastic that is completely decomposed by itself into water and carbon dioxide or water and methane gas by microorganisms present in nature, such as bacteria, algae, and mold. In the past, photodegradable plastic or biodestructible plastic has been mainly used. Recently, the development of biodegradable plastic has been treated as an important issue. Biodegradable plastic distinguishes from the existing petroleum-based plastic because of the use of natural plant resources in terms of the raw material, and may provide cleanliness that is completely decomposed into only water and carbon dioxide by microorganisms in nature. Therefore, it is a global trend to develop biodegradable plastic as mainstream. On the other hand, when a biodegradable resin is included in order to improve biodegradability, compatibility with thermoplastic plastic is mainly a problem. In the case of starch as an example of a biodegradable resin, compatibility can be solved by changing physical properties by introducing a substituent to hydroxy (—OH) or by applying a method of generating a radical and copolymerizing with a vinyl-based monomer. However, in this case, there is somewhat limitation in that it is difficult to provide a satisfactory level of compatibility or biodegradability. Recently, various technologies are being developed to enhance compatibility and improve biodegradability and mechanical properties. For example, Korean Patent Publication No. 10-2018-0023037 discloses a thermoplastic film composition including a polymer blend of an immiscible polymer component. The composition includes a plasticized natural polymer, a polyolefin, a biodegradable polymer, and a compatibilizing agent in the same polymer molecule. A plasticized natural component and a biodegradable polymer component form a majority phase, and a petroleum-based olefin polymer forms a minority phase. It is also mentioned that the composition can be produced into a film including a renewable natural polymer componen