KR102579310B1 - Biodegradable resin compositions including polyvinylalcohol and manufacturing methods thereof - Google Patents

Abstract

It relates to biodegradable resin compositions and methods for producing them, and more specifically, to technologies for improving biodegradability, including polyethylene, biodegradable resins, polybutylene adipate terephthalate (PBAT), and polyvinyl alcohol (PVA). will be.

Description

Biodegradable resin compositions including polyvinylalcohol and manufacturing methods thereof}

The present invention relates to a biodegradable resin composition and a method for manufacturing the same, and more specifically, to a biodegradable resin composition containing polyethylene, biodegradable resin, polybutylene adipate terephthalate (PBAT), and polyvinyl alcohol (PVA), with improved biodegradability. It's about technology.

Due to the excellent physical properties of plastic and its cheap and light characteristics, various polymer materials have been developed centered on plastic, breaking away from the limitations of natural materials, thereby establishing modern scientific civilization. Plastics are strong, light, tough, and do not decompose easily. Because of these properties, they are used in a variety of ways, from industrial materials to disposable materials. Research has been conducted for a long time to further improve the strength and durability of synthetic resins such as plastics, and these efforts are still continuing. However, environmental pollution caused by plastic waste is becoming increasingly serious. For example, due to the detection of highly toxic dioxin and the leakage of environmental hormones, there is not only a social demand for eco-friendly plastics, but also legal regulations in each country for the use of non-degradable plastics. The standards are also becoming increasingly stronger. To solve this problem, the development of biodegradable polymers is considered a very important issue, and is also attracting attention as an important field in the plastics industry.

In general, according to the American Society for Testing and Materials (ASTM), degradable plastic refers to a plastic whose chemical structure changes significantly over a certain period of time under specific environmental conditions and whose change in properties can be measured using standard test methods. It can be divided into collapsible and biodegradable plastics.

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, it has the disadvantage of not decomposing when buried in the ground where light is blocked. Biodegradable plastic is a partially degradable plastic manufactured by adding a certain amount of biodegradable material such as starch to general non-degradable general-purpose resin (polyethylene, polypropylene, etc.). In Korea, it is a biodegradable plastic to avoid confusion with biodegradable plastic. It is classified separately using the term plastic. Biodegradable plastic generally refers to plastic that is completely decomposed into water and carbon dioxide or water and methane gas by microorganisms that exist in nature, such as bacteria, algae, and mold.

In the past, photodegradable plastics or biodegradable plastics were mainly used, but recently, the development of biodegradable plastics has become an important issue. This not only differentiates it from existing petroleum-based plastics by using natural plant resources from the raw material point of view, but also provides cleanliness by being completely decomposed into water and carbon dioxide by microorganisms in the natural world, so the global trend is also toward biodegradable plastics becoming mainstream. It is being developed as it is being achieved.

For example, Korean Patent Publication No. 10-2018-0023037 discloses a thermoplastic film composition comprising a polymer blend of immiscible polymer components. The composition includes a plasticized natural polymer, a polyolefin, a biodegradable polymer and a compatibilizer for the same polymer molecules. Plasticized natural components and biodegradable polymer components form the majority phase, and petroleum-based olefin polymers form the minority phase. In addition, it is mentioned that the composition can be manufactured as a film containing renewable natural polymer components.

For another example, Korean Patent Publication No. 10-2017-0075052 (i) biodegradable resin (ii) starch in which at least one of the hydroxyl groups (-OH groups) of the glucose unit is hydrophobized with silane (iii) biodegradable polymer A resin composition for mulching film containing one or more compatibilizers selected from the group consisting of a graft copolymer grafted with maleic anhydride (MA), an epoxidized oil, and a multifunctional compound having an epoxy group. and the film are disclosed. As a result, the processability and mulching functionality of the film can be improved, and the tensile strength and tensile elongation of the film are improved.

In the case of the above patents, there are some limitations in that it is difficult to show complete biodegradability because most of them contain two-component resin. Therefore, development research is still needed to provide better properties and excellent biodegradability. This invention was also completed after a long period of research to satisfy these requirements.

Korean Patent Publication No. 10-2018-0023037 (2018.03.06) Korean Patent Publication No. 10-2017-0075052 (2017.07.03)

The present invention aims to solve all of the above-mentioned problems.

The purpose of the present invention is to improve the compatibility of biodegradable resin compositions and thereby improve the degradability of polyethylene.

The purpose of the present invention is to provide a film containing the biodegradable resin composition so that it can be applied to various fields such as industrial, food, and agricultural purposes.

As a technical means for achieving the above-described technical problem, one aspect of the present invention is,

Provided is a biodegradable resin composition containing polyethylene, biodegradable resin, polybutylene adipate terephthalate (PBAT), and polyvinyl alcohol (PVA).

The polyethylene includes a polymer selected from the group consisting of high-density polyethylene (HDPE), low-density polyethylene (LDPE), medium-density polyethylene (MDPE), linear low-density polyethylene (LLDPE), ethylene vinyl copolymer (EVA), and combinations thereof. It may be.

The biodegradable resin includes thermoplastic starch (TPS), polylactic acid (PLA), polycaprolactone (PCL), polybutylene succinate (PBS), polyglycolic acid (PGA), polyhydroxyalkanoate (PHA), It may contain a material selected from the group consisting of polyhydroxybutyrate (PHB), cellulose, chitin, and combinations thereof.

The thermoplastic starch may include at least one selected from rice starch, wheat starch, corn starch, sweet potato starch, potato starch, tapioca starch, cassava starch, and modified starches thereof.

The weight average molecular weight of the polyethylene may be 100,000 to 1,000,000.

The weight average molecular weight of polybutylene adipate terephthalate (PBAT) may be 10,000 to 100,000.

The melting temperature of the biodegradable resin composition is 100°C to 130°C, and the melt index may be 0.01 to 10g/10min at 2.16Kg at 190°C based on ASTM D1238.

With respect to 100 parts by weight of the polyethylene, the content of the biodegradable resin is 10 parts by weight to 600 parts by weight, the content of the polybutylene adipate terephthalate (PBAT) is 10 parts by weight to 500 parts by weight, and the polyvinyl The content of alcohol (PVA) may be 10 to 30 parts by weight.

With respect to 100 parts by weight of the polyethylene, the content of the biodegradable resin is 40 parts by weight to 100 parts by weight, the content of the polybutylene adipate terephthalate (PBAT) is 10 parts by weight to 50 parts by weight, and the polyvinyl The content of alcohol (PVA) may be 10 to 30 parts by weight.

With respect to 100 parts by weight of polyethylene, the content of the biodegradable resin is 60 parts by weight to 70 parts by weight, the content of polybutylene adipate terephthalate (PBAT) is 30 parts by weight to 45 parts by weight, and the polyvinyl The content of alcohol (PVA) may be 10 to 25 parts by weight.

In addition, another aspect of the present invention is,

A biodegradable film comprising the biodegradable resin composition is provided.

The biodegradable film has a weight change of -15% or more compared to the weight before landfill after being buried in soil for 4 weeks, and the weight change may be expressed by Equation 1 below.

[Equation 1]

Weight change = (Weight of biodegradable film after 4 weeks of landfill - Weight of biodegradable film before landfill) / (Weight of biodegradable film after 4 weeks of landfill)

In Equation 1, the weight change amount is a negative value, meaning that the amount of change greater than -15% increases to a negative value.

The biodegradable film has a thickness change of -12% or more compared to the thickness before burial after being buried in soil for 4 weeks, and the thickness change may be expressed by Equation 2 below.

[Equation 2]

Thickness change = (Thickness of biodegradable film after 4 weeks of landfill - Thickness of biodegradable film before landfill) / (Thickness of biodegradable film after 4 weeks of landfill)

In Equation 2, the thickness change amount is a negative value, meaning that the amount of change in thickness greater than -12% increases to a negative value.

The film may be applicable to at least one selected from industrial films, food films, agricultural films, and household films.

In addition, another aspect of the present invention is,

A method for producing a biodegradable resin composition prepared by a melt blending method is provided, including polyethylene, biodegradable resin, polybutylene adipate terephthalate (PBAT), and polyvinyl alcohol (PVA).

The melt blending may be carried out at 160°C to 210°C.

The melt blending may be performed using at least one selected from an extruder, a kneader, a Brabender plasticoder, a mixing roll, and a mixer.

The extruder may be one or more selected from a single screw extruder, a twin screw extruder, a single screw extruder, and a twin screw extruder.

The biodegradable resin composition according to the present invention improves compatibility by providing a combination of four components including polyethylene, biodegradable resin, polybutylene adipate terephthalate (PBAT), and polyvinyl alcohol, thereby improving the decomposability of polyethylene. It provides the desired effect.

The film containing the biodegradable resin composition according to the present invention can be applied to various fields such as industrial, food, and agricultural purposes, and provides excellent biodegradability, contributing to solving environmental problems.

Figure 1 is a photograph comparing the degradability of films containing a biodegradable resin composition according to an experimental example of the present invention.
Figure 2 is a graph showing the amount of change in weight over time of a film containing a biodegradable resin composition according to an experimental example of the present invention.

Hereinafter, the present invention will be described in more detail. However, the present invention can be implemented in various different forms, and the present invention is not limited to the embodiments described herein, and the present invention is only defined by the claims to be described later.

In addition, the terms used in the present invention are only used to describe specific embodiments and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In the entire specification of the present invention, 'including' a certain element means that other elements may be further included rather than excluding other elements, unless specifically stated to the contrary.

The first aspect of the present application is,

Provided is a biodegradable resin composition containing polyethylene, biodegradable resin, polybutylene adipate terephthalate (PBAT), and polyvinyl alcohol (PVA).

Hereinafter, the biodegradable resin composition according to the first aspect of the present application will be described in detail.

First, in one embodiment of the present application, biodegradable means plastic that is decomposed into water and CO ₂ or CH ₄ by microorganisms such as bacteria, algae, and mold. This may mean that not only physical disintegration of molded products such as plastics occurs, but also a decrease in molecular weight due to cleavage of the main chain of the polymer.

In one embodiment of the present application, the biodegradable resin composition is a biodegradable resin through a compound combination of four components including polyethylene, biodegradable resin, polybutylene adipate terephthalate (PBAT), and polyvinyl alcohol (PVA). A composition may be provided.

In one embodiment of the present application, polyethylene is inexpensive and has excellent mechanical properties and processability, but it is a major cause of environmental pollution in the environment due to its non-degradability. Therefore, in the present invention, in order to improve biodegradability while maintaining the excellent mechanical properties and processability of polyethylene, biodegradable resin, polybutylene adipate terephthalate (PBAT), and polyvinyl alcohol (PVA) may be provided. there is.

In one embodiment of the present application, the polyethylene is high-density polyethylene (HDPE), very-low-density polyethylene (VLDPE), low-density polyethylene (LDPE), and medium-density polyethylene (MDPE). , Medium Density Polyethylene), Linear Low Density Polyethylene (LLDPE), Ethylene-Vinyl Acetate copolymer (EVA), and combinations thereof. Preferably, linear low density polyethylene (LLDPE) is provided to provide excellent impact resistance and durability.

In one embodiment of the present application, the weight average molecular weight of the polyethylene may be in the hundreds of thousands to millions, and the weight average molecular weight may be in the range of 100,000 to 1,000,000, preferably in the range of 100,000 to 300,000.

In one embodiment of the present application, the biodegradable resin is thermoplastic starch (TPS), polylactic acid (PLA), polycaprolactone (PCL), polybutylene succinate (PBS), polyglycolic acid (PGA), and polyhydric acid. It may contain a material selected from the group consisting of hydroxyalkanoate (PHA), polyhydroxybutyrate (PHB), cellulose, chitin, and combinations thereof, and preferably contains thermoplastic starch (TPS). It may be.

In one embodiment of the present application, polylactic acid, polycaprolactone, polybutylene succinate, and polyglycolic acid correspond to aliphatic polyesters, and they may have excellent biodegradability by microorganisms and provide properties such as biocompatibility. there is. In particular, polyglycolic acid is widely used in medical applications due to its excellent mechanical properties such as high strength and high heat resistance.

In one embodiment of the present application, the polyhydroxyalkanoate corresponds to polyester and may be characterized by excellent biodegradability and excellent decomposability under any conditions such as aerobic, anaerobic, and compost conditions. In addition, polyhydroxybutyrate is a natural polyester and belongs to the polyhydroxyalkanoate class. It is a homopolymer of D-3-hydroxy-butyric acid connected in a straight line, and is very diverse. It is an energy store synthesized by bacteria within cells and may provide biological functions such as starch or glycogen.

In one embodiment of the present application, cellulose, chitin, and natural polymers can be provided as eco-friendly materials due to their excellent biodegradability, easy supply, and non-toxic properties.

In one embodiment of the present application, the thermoplastic starch is obtained from plants and refers to a granular material consisting of two components, amylose and amylopectin, for example, rice starch, wheat starch, corn starch, sweet potato starch, potato starch, It may be provided containing at least one or more selected from tapioca starch, cassava starch, and modified starches thereof. Modified starch may be provided by physically or chemically treating starch, such as α-starch, acid-treated starch, oxidized starch, amphoteric starch, ester starch, and ether starch. The starch has excellent biodegradability and is composed of amylose and amylopectin, and the glucose of amylose contains a hydroxy (-OH) group, making it hydrophilic and hydrogen bonding.

In one embodiment of the present application, polybutylene adipate terephthalate (PBAT) may be a biodegradable resin and serve as a compatibilizer at the same time. In general, polyolefins have non-polar chemical properties and have low kneading properties with polar thermoplastic starches, so their compatibility has been problematic. Therefore, by introducing the polybutylene adipate terephthalate (PBAT), compatibility can be improved and excellent biodegradability of polyethylene, the base resin, can be provided at the same time.

In one embodiment of the present application, the weight average molecular weight of polybutylene adipate terephthalate (PBAT) may be 10,000 to 100,000, preferably 20,000 to 50,000.

In one embodiment of the present application, the polyvinyl alcohol (PVA), like the polybutylene adipate terephthalate (PBAT), may be a biodegradable resin and serve as a compatibilizer at the same time. Therefore, by introducing polyvinyl alcohol (PVA), which has both hydrophilic and hydrophobic groups, compatibility can be improved and excellent biodegradability of polyethylene, the base resin, can be provided at the same time. Meanwhile, polybutylene adipate terephthalate (PBAT) and polyvinyl alcohol (PVA) must each be included in an appropriate amount in the biodegradable resin composition, and if included outside the appropriate content range, the function of the biodegradable resin composition may be impaired. It may be deteriorating. This will be explained in more detail below.

In one embodiment of the present application, the melting temperature of the biodegradable resin composition is 100°C to 130°C and the melt index of the resin composition is 0.01 to 10 g/10min at 2.16Kg at 190°C based on ASTM D1238. You can. The melt temperature may be measured by differential scanning calorimetry (DSC) or dynamic mechanical analysis (DMA), which are commonly measured methods, and the melt index (MI) may be measured by ASTM D1238. there is.

In one embodiment of the present application, with respect to 100 parts by weight of polyethylene, the content of the biodegradable resin may be 10 parts by weight to 600 parts by weight, preferably 40 parts by weight to 100 parts by weight, and more preferably. may be 60 to 70 parts by weight. According to one embodiment of the present application, the polyethylene and biodegradable resin may be included in a weight ratio of 45:30. At this time, if the content of the biodegradable resin is less than 10 parts by weight relative to 100 parts by weight of polyethylene, it may be economically disadvantageous, and if the content of polyethylene is relatively too high, problems may occur in the biodegradable decomposition effect. In addition, when the content of the biodegradable resin exceeds 600 parts by weight, the content of polyethylene is relatively low, so there may be limitations in providing excellent mechanical properties and processability that conventional plastics can provide, and specifically, tensile strength (Tensile strength). Problems such as decreased strength, elongation, and drop impact strength may occur.

In one embodiment of the present application, with respect to 100 parts by weight of polyethylene, the content of polybutylene adipate terephthalate (PBAT) is 10 parts by weight to 500 parts by weight, and the content of polyvinyl alcohol (PVA) is 10 parts by weight. It may be from 10 parts by weight to 30 parts by weight, and preferably the polybutylene adipate terephthalate (PBAT) may be from 10 parts by weight to 50 parts by weight, and more preferably the polybutylene adipate terephthalate (PBAT) is 30 parts by weight. to 45 parts by weight, and polyvinyl alcohol (PVA) may be 10 to 25 parts by weight. According to one embodiment of the present application, the polyethylene, polybutylene adipate terephthalate (PBAT), and polyvinyl alcohol (PVA) may be included in a weight ratio of 45:15 to 20:5 to 10. At this time, when the content of polybutylene adipate terephthalate (PBAT) is less than 10 parts by weight or the content of polyvinyl alcohol (PVA) is less than 10 parts by weight based on 100 parts by weight of polyethylene, the biodegradation effect is It may be insignificant, and if the content of polybutylene adipate terephthalate (PBAT) exceeds 500 parts by weight or the content of polyvinyl alcohol (PVA) exceeds 30 parts by weight, problems may arise in compatibility and processability with polyethylene. there is.

The second aspect of the present application is,

A biodegradable film comprising the biodegradable resin composition according to the first aspect of the present application is provided.

Detailed description of parts overlapping with the first aspect of the present application has been omitted, but the content described in the first aspect of the present application can be applied equally even if the description is omitted in the second aspect.

Hereinafter, the biodegradable film according to the second aspect of the present application will be described in detail.

In one embodiment of the present application, the film can be applied to at least one selected from industrial films, food films, agricultural films, and household films, and provides improved mechanical properties while providing the same mechanical properties provided by existing plastics. Biodegradability may be something that can be provided. In this regard, referring to Figures 1 and 2, which will be described later, the excellent decomposability of the film can be confirmed. Therefore, after use of the film, it can be composted in a facility (compost) that meets certain conditions. In addition, even if combustion is unavoidable, the amount of heat generated is low, so the emission of harmful substances such as dioxin can be minimized.

In one embodiment of the present application, the biodegradable film has a weight change of -15% or more compared to the weight before landfill after being buried in soil for 4 weeks, and the weight change may be expressed by Equation 1 below.

[Equation 1]

Weight change = (Weight of biodegradable film after 4 weeks of landfill - Weight of biodegradable film before landfill) / (Weight of biodegradable film after 4 weeks of landfill)

At this time, in Equation 1, the weight change amount is a negative value, which may mean that -15% or more increases to a negative value. Meanwhile, the weight change amount may preferably be -18% or more, and more preferably about -19% to -20%.

In one embodiment of the present application, the biodegradable film has a thickness change of -12% or more compared to the thickness before burial after being buried in soil for 4 weeks, and the thickness change may be expressed by Equation 2 below.

[Equation 2]

Thickness change = (Thickness of biodegradable film after 4 weeks of landfill - Thickness of biodegradable film before landfill) / (Thickness of biodegradable film after 4 weeks of landfill)

At this time, in Equation 2, the amount of thickness change is a negative value, which may mean that -12% or more increases to a negative value. Meanwhile, the amount of change in thickness may preferably be -13% or more, and more preferably about -13% to -15%.

In one embodiment of the present application, the thickness of the film may be 20 to 40 μm, and preferably 30 μm.

The third aspect of the present application is,

A method for producing a biodegradable resin composition prepared by a melt blending method is provided, including polyethylene, biodegradable resin, polybutylene adipate terephthalate (PBAT), and polyvinyl alcohol (PVA).

Detailed description of parts overlapping with the first and second aspects of the present application has been omitted, but the content described in the first and second aspects of the present application can be applied equally even if the description is omitted in the third aspect. .

Hereinafter, the method for producing the biodegradable resin composition according to the third aspect of the present application will be described in detail.

In one embodiment of the present application, with respect to 100 parts by weight of polyethylene, the content of the biodegradable resin may be 10 parts by weight to 600 parts by weight, preferably 40 parts by weight to 100 parts by weight, and more preferably. may be 60 to 70 parts by weight. According to one embodiment of the present application, the polyethylene and biodegradable resin may be included in a weight ratio of 45:30. At this time, if the content of the biodegradable resin is less than 10 parts by weight relative to 100 parts by weight of polyethylene, it may be economically disadvantageous, and if the content of polyethylene is relatively too high, problems may occur in the biodegradable decomposition effect. In addition, when the content of the biodegradable resin exceeds 600 parts by weight, the content of polyethylene is relatively low, so there may be limitations in providing excellent mechanical properties and processability that conventional plastics can provide, and specifically, tensile strength (Tensile strength). Problems such as decreased strength, elongation, and drop impact strength may occur.

In one embodiment of the present application, with respect to 100 parts by weight of polyethylene, the content of polybutylene adipate terephthalate (PBAT) is 10 parts by weight to 500 parts by weight, and the content of polyvinyl alcohol (PVA) is 10 parts by weight. It may be from 10 parts by weight to 30 parts by weight, and preferably the polybutylene adipate terephthalate (PBAT) may be from 10 parts by weight to 50 parts by weight, and more preferably the polybutylene adipate terephthalate (PBAT) is 30 parts by weight. to 45 parts by weight, and polyvinyl alcohol (PVA) may be 10 to 25 parts by weight. According to one embodiment of the present application, the polyethylene, polybutylene adipate terephthalate (PBAT), and polyvinyl alcohol (PVA) may be included in a weight ratio of 45:15 to 20:5 to 10. At this time, when the content of polybutylene adipate terephthalate (PBAT) is less than 10 parts by weight or the content of polyvinyl alcohol (PVA) is less than 10 parts by weight based on 100 parts by weight of polyethylene, the biodegradation effect is It may be insignificant, and if the content of polybutylene adipate terephthalate (PBAT) exceeds 500 parts by weight or the content of polyvinyl alcohol (PVA) exceeds 30 parts by weight, problems may arise in compatibility and processability with polyethylene. there is.

In one embodiment of the present application, the melt blending is provided using at least one selected from the group consisting of an extruder, a kneader, a Brabender Plasticorder, a mixing roll, and a mixer. You can.

In one embodiment of the present application, the extruder may be provided using one or more selected from a single-screw extruder, a twin-screw extruder, a single screw, and a twin-screw extruder, and is preferably provided using a twin-screw extruder to provide excellent kneading properties and It can provide easy processing.

According to an embodiment of the present invention, the process can be carried out by optimizing process conditions according to the various raw materials to be added in the melt blending. The melting temperature may be 100°C to 300°C, preferably 160°C to 210°C, and the rotation speed of the extruder screw may be 40rpm to 700rpm, preferably 100rpm to 200rpm. .

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement it. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein.

Example 1. Preparation of biodegradable film

45% by weight of LLDPE (M2010EA, Hanwha Chemical), 20% by weight of PBAT (SOLPOL-1000, GIOSOLTEC), 30% by weight of TPS (Bionyl, Daesang), and 5% by weight of polyvinyl alcohol (PVA) were mixed, as shown in Table 1 below. A mixture with the same composition was prepared.

The prepared mixture was placed in an extruder and heated at a mixing zone temperature of 190°C to prepare a biodegradable resin composition, and immediately extruded to prepare a blown film. At this time, the blown film processing conditions were 40mmΦ for the screw, 75mmΦ for the die, 2mm for the die gap, and the speed of the screw was 180rpm.

Example 2. Preparation of biodegradable film

A biodegradable film was prepared in the same manner as in Example 1, except that 45% by weight of LLDPE, 15% by weight of PBAT, 30% by weight of TPS, and 10% by weight of PVA were mixed.

Comparative example 1. Preparation of film

A film was manufactured using the same method as in Example 1, except that 45% by weight of LLDPE, 25% by weight of PBAT, and 30% by weight of TPS were mixed.

Comparative example 2. Preparation of film

A film was manufactured in the same manner as in Example 1, except that 45% by weight of LLDPE, 10% by weight of PBAT, 30% by weight of TPS, and 15% by weight of PVA were mixed.

Comparative example 3. Preparation of the film

A film was manufactured in the same manner as in Example 1, except that 45% by weight of LLDPE, 5% by weight of PBAT, 30% by weight of TPS, and 20% by weight of PVA were mixed.

[Table 1]

Experiment example. Measurement of biodegradation effect of biodegradable film

Films according to Examples and Comparative Examples having composition ratios according to Table 1 above were buried in soil, and changes in weight and thickness ratio before and after burial were observed. Landfill conditions are important for a constant temperature and moisture content that can activate the growth of microorganisms, and the temperature and moisture content were maintained at 58°C and 50% using a constant temperature and humidity chamber under standard compost conditions.

Additionally, experiments were conducted 2 and 4 weeks after landfill. Thereafter, the weight change and thickness ratio change of the film are shown in Figures 1 and 2.

Referring to Figures 1 and 2, which are the results according to the Examples and Comparative Examples according to the present invention, in the case of Examples 1 and 2 according to the present invention, the weight change of the film was about -19% compared to Comparative Examples 1 to 3. It can be confirmed that it is significantly higher, and the thickness change rate is about -13.7% or more, confirming that it has an excellent biodegradation effect.

Therefore, in the case of the present invention, compatibility is improved by providing a resin composition containing four components: polyethylene, biodegradable resin, polybutylene adipate terephthalate (PBAT), and polyvinyl alcohol (PVA), and the resin composition is adjusted to an appropriate content range. It was confirmed that its inclusion had the effect of improving the decomposability of polyethylene.

In addition, the film containing the biodegradable resin composition according to the present invention can be applied to various fields such as industrial, food, and agricultural purposes, and can be expected to contribute to solving environmental problems by providing excellent biodegradability.

Above, the present invention has been described in detail along with preferred embodiments with reference to the drawings, but the scope of the technical idea of the present invention is not limited to these drawings and examples. Accordingly, various modifications or equivalent embodiments may exist within the scope of the technical idea of the present invention. Therefore, the scope of rights of the technical idea according to the present invention should be interpreted in accordance with the claims, and technical ideas within the scope equivalent or equivalent thereto should be interpreted as falling within the scope of the rights of the present invention.

Claims (18)

Contains polyethylene, biodegradable resin, polybutylene adipate terephthalate (PBAT), and polyvinyl alcohol (PVA),
For 100 parts by weight of the polyethylene,
The content of the biodegradable resin is 60 parts by weight to 70 parts by weight,
The content of polybutylene adipate terephthalate (PBAT) is 30 to 45 parts by weight,
A biodegradable resin composition wherein the polyvinyl alcohol (PVA) content is 10 to 25 parts by weight.
According to paragraph 1,
The polyethylene includes a polymer selected from the group consisting of high-density polyethylene (HDPE), low-density polyethylene (LDPE), medium-density polyethylene (MDPE), linear low-density polyethylene (LLDPE), ethylene vinyl copolymer (EVA), and combinations thereof. A biodegradable resin composition.
According to paragraph 1,
The biodegradable resin includes thermoplastic starch (TPS), polylactic acid (PLA), polycaprolactone (PCL), polybutylene succinate (PBS), polyglycolic acid (PGA), polyhydroxyalkanoate (PHA), A biodegradable resin composition comprising a material selected from the group consisting of polyhydroxybutyrate (PHB), cellulose, chitin, and combinations thereof.
According to paragraph 3,
The thermoplastic starch is a biodegradable resin composition comprising at least one selected from rice starch, wheat starch, corn starch, sweet potato starch, potato starch, tapioca starch, cassava starch, and modified starches thereof.
According to paragraph 1,
A biodegradable resin composition wherein the weight average molecular weight of the polyethylene is 100,000 to 1,000,000.
According to paragraph 1,
A biodegradable resin composition wherein the weight average molecular weight of the polybutylene adipate terephthalate (PBAT) is 10,000 to 100,000.
According to paragraph 1,
The biodegradable resin composition has a melting temperature of 100°C to 130°C, and a melt index of 0.01 to 10g/10min at 2.16Kg at 190°C based on ASTM D1238.
delete delete delete A biodegradable film comprising the biodegradable resin composition according to claim 1.
According to clause 11,
After being buried in soil for 4 weeks, the biodegradable film has a weight change of -15% or more compared to the weight before landfill,
A biodegradable film wherein the weight change amount is expressed by the following equation 1:
[Equation 1]
Weight change = (Weight of biodegradable film after 4 weeks of landfill - Weight of biodegradable film before landfill) / (Weight of biodegradable film after 4 weeks of landfill)
(In Equation 1 above, the weight change amount is a negative value, meaning that -15% or more increases to a negative value.)
According to clause 11,
The biodegradable film has a thickness change of -12% or more after 4 weeks of burial in soil compared to the thickness before burial,
A biodegradable film in which the thickness change amount is expressed by the following equation 2:
[Equation 2]
Thickness change = (Thickness of biodegradable film after 4 weeks of landfill - Thickness of biodegradable film before landfill) / (Thickness of biodegradable film after 4 weeks of landfill)
(In Equation 2 above, the amount of thickness change is a negative value, meaning that above -12% or more increases to a negative value.)
According to clause 11,
The film is a biodegradable film that can be applied to at least one selected from industrial films, food films, agricultural films, and household films.
Contains polyethylene, biodegradable resin, polybutylene adipate terephthalate (PBAT), and polyvinyl alcohol (PVA),
For 100 parts by weight of the polyethylene,
The content of the biodegradable resin is 60 parts by weight to 70 parts by weight,
The content of polybutylene adipate terephthalate (PBAT) is 30 to 45 parts by weight,
The content of polyvinyl alcohol (PVA) is 10 to 25 parts by weight,
Method for producing a biodegradable resin composition manufactured by melt blending method.
According to clause 15,
A method for producing a biodegradable resin composition, wherein the melt blending is carried out at 160°C to 210°C.
According to clause 15,
The melt blending is a method of producing a biodegradable resin composition using at least one selected from an extruder, a kneader, a Brabender plasticoder, a mixing roll, and a mixer.
According to clause 17,
The extruder is a method of producing a biodegradable resin composition using at least one selected from a single-screw extruder, a twin-screw extruder, a single-screw extruder, and a twin-screw extruder.