WO2023043101A1

WO2023043101A1 - Biodegradable film, method for manufacturing same, and eco-friendly packaging material comprising same

Info

Publication number: WO2023043101A1
Application number: PCT/KR2022/013139
Authority: WO
Inventors: 한권형; 이석인
Original assignee: 에스케이씨 주식회사
Priority date: 2021-09-15
Filing date: 2022-09-01
Publication date: 2023-03-23
Also published as: KR102656673B1; KR20230040198A

Abstract

An embodiment relates to a biodegradable film, a method for manufacturing same, and an eco-friendly packaging material comprising same, wherein the biodegradable film comprises a first resin including a polylactic acid-based resin and a second resin including a vinyl acetate-based resin and has a thermal adhesive strength of 4 N/15 mm or more. The biodegradable film has excellent thermal adhesiveness and an improvement in flexibility, transparency, and the degree of noise, and thus enables the provision of not only a packaging film, but also a high-quality eco-friendly packaging material by being utilized as a packaging material in various fields.

Description

Biodegradable film, manufacturing method thereof, and eco-friendly packaging material including the same

The present invention relates to a biodegradable film, a manufacturing method thereof, and an eco-friendly packaging material including the same.

Plastic films often used for packaging include cellophane, polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PP), nylon, and polyethylene terephthalate (PET). .

However, cellophane films cause severe environmental pollution during the manufacturing process and are subject to many regulations in production itself, and polyvinyl chloride films generate harmful substances such as dioxins when incinerated, so their use is subject to many regulations. In addition, polyethylene film lacks heat resistance and mechanical properties, so its use is limited except for low-grade packaging applications. Polypropylene, nylon, and polyethylene terephthalate have relatively stable molecular structures and have good mechanical properties. However, when landfilled without special treatment after being used for packaging, they are hardly decomposed due to chemical and biological stability and accumulate in the ground. It shortens the life of the landfill and causes problems of soil pollution.

In order to compensate for the disadvantages of such non-degradable plastic films, polylactic acid films, which are aliphatic polyesters with high biodegradability of the resin itself, have recently been used in various ways, but these films have good mechanical properties, but have a unique crystal structure. Due to the lack of flexibility, its use is limited.

In order to solve this problem, Japanese Patent Laid-Open No. 2006-272712 discloses a method for producing a film using only a biodegradable aliphatic polyester other than polylactic acid, but in this case, the glass transition temperature is too low for biaxial stretching. Not only is it not easy to manufacture the film by this method, but the final film has low mechanical strength and high thermal shrinkage, causing many problems during processing.

Meanwhile, Japanese Patent Publication No. 2003-160202 discloses a method of imparting flexibility and heat sealing to a film by blending polylactic acid with aliphatic-aromatic co-polyester, but according to this method, polylactic acid Due to the low compatibility with the aliphatic-aromatic co-polyester and the use of a plasticizer, the transparency of the final film is remarkably lowered and the thermal bonding strength is poor, making it difficult to use it for packaging applications requiring transparency and adhesiveness.

[Prior art literature]

[Patent Literature]

(Patent Document 1) Japanese Unexamined Patent Publication No. 2006-272712

(Patent Document 2) Japanese Unexamined Patent Publication No. 2003-160202

An object of the present invention is to mix a polylactic acid (PLA)-based resin and a vinyl acetate (VAc)-based resin and adjust the thermal bonding strength within a specific range, thereby providing excellent thermal bonding properties as well as flexibility, transparency and It is intended to provide a biodegradable film with improved noise level at the same time.

Another object of the present invention is to provide a method for manufacturing a biodegradable film for adjusting the properties of the biodegradable film to an optimal range.

Another object of the present invention is to provide a biodegradable, eco-friendly, and high-quality eco-friendly packaging material by using a biodegradable film having excellent properties.

The present invention is a first resin comprising a polylactic acid-based resin; and a second resin including a vinyl acetate-based resin, and one side of a biodegradable film specimen having a width of 15 mm and a length of 150 mm and one side of the polylactic acid-based resin film are thermally bonded to each other at 100° C. and 1.5 bar for 1 second. After that, the thermal bonding strength (N/15mm) when peeling at a peeling angle of 180 ° and a peeling speed of 200 mm / min by mounting it on a universal testing machine (UTM) so that the distance between chucks is 50 mm is 4 N / 15 mm or more , to provide a biodegradable film.

In addition, the present invention comprises the steps of preparing a sheet by mixing a first resin including a polylactic acid-based resin and a second resin including a vinyl acetate-based resin and then melting and extruding them (step 1); preparing a film by stretching the melt-extruded sheet (step 2); It provides a method for producing a biodegradable film comprising a; and heat-setting the stretched film (step 3).

In addition, the present invention includes a biodegradable film, wherein the biodegradable film includes a first resin including a polylactic acid-based resin; and a second resin including a vinyl acetate-based resin.

The biodegradable film according to the embodiment is obtained by mixing a polylactic acid (PLA)-based resin and a vinyl acetate (VAc)-based resin and adjusting the heat-adhesive strength within a specific range, thereby having excellent heat-adhesive properties and flexibility of the biodegradable film. , transparency, and noise level can be simultaneously improved.

In addition, the manufacturing method of the biodegradable film according to the embodiment can provide a biodegradable film that is biodegradable and has excellent properties through a simple, economical and efficient manufacturing process.

Furthermore, the biodegradable film according to the embodiment can be used in various fields as a packaging film as well as a packaging material to provide a high-quality, eco-friendly packaging material.

Figure 1 schematically shows a method for producing a biodegradable film according to an embodiment of the present invention.

Figure 2 schematically shows a method for measuring thermal bonding strength of a biodegradable film according to an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail.

Embodiments are not limited to the contents disclosed below, and may be modified in various forms unless the gist of the invention is changed.

In this specification, when a certain component is said to "include", this means that it may further include other components, not excluding other components, unless otherwise stated.

In this specification, a singular expression is interpreted as a meaning including a singular number or a plurality interpreted in context unless otherwise specified.

In addition, it should be understood that all numerical ranges representing physical property values, dimensions, reaction conditions, etc. of components described in this specification are modified by the term "about" in all cases unless otherwise specified.

In this specification, terms such as first, second, and third are used to describe various components, and the components are not limited by the terms. These terms are only used for the purpose of distinguishing one component from another.

In one embodiment, by including a polylactic acid-based resin and a vinyl acetate-based resin together and adjusting the thermal bonding strength within a specific range, excellent thermal bonding properties can be secured, enabling thermal bonding to various substrates as well as flexibility. , transparency, and noise level can be simultaneously improved. Furthermore, it has technical significance in that it is possible to implement a high-quality eco-friendly packaging material capable of exhibiting excellent characteristics while being biodegradable in an economical and efficient way by further improving the physical properties and moldability of the film.

[생분해성 필름][Biodegradable film]

A biodegradable film according to an embodiment includes a first resin including a polylactic acid (PLA)-based resin; And a second resin including a vinyl acetate (VAc)-based resin; including, one side of a biodegradable film specimen having a width of 15 mm and a length of 150 mm and one side of the polylactic acid-based resin film at 100° C. and 1.5 bar for 1 second. After being thermally bonded to each other, the thermal bonding strength (N/15mm) when peeling at a peeling angle of 180 ° and a peeling speed of 200 mm/min by mounting them in a universal testing machine (UTM) with a gap between chucks of 50 mm is 4 N /15 mm or more.

Since the polylactic acid-based resin is based on biomass, unlike petroleum-based resins, it is possible to utilize renewable resources and emits less carbon dioxide, which is the main culprit of global warming, compared to conventional resins during production, It is eco-friendly as it is biodegraded by moisture and microorganisms when landfilled.

The polylactic acid-based resin may have a weight average molecular weight (Mw) of 100,000 to 1,000,000 g/mol, such as 100,000 to 800,000 g/mol, 100,000 to 500,000 g/mol, or 100,000 to 300,000 g/mol. The weight average molecular weight (Mw) may be measured by gel permeation chromatography (GPC). When the weight average molecular weight (Mw) of the polylactic acid-based resin satisfies the above range, mechanical properties and optical properties of the biodegradable film may be further improved.

The polylactic acid-based resin may include L-lactic acid, D-lactic acid, D, L-lactic acid, or a combination thereof.

Specifically, the polylactic acid-based resin may be a random copolymer of L-lactic acid and D-lactic acid.

In this case, the content of the D-lactic acid is, for example, 1 wt% to 5 wt%, for example 1 wt% to 4 wt%, for example 2 wt% to 4 wt%, for example 1 wt% based on the total weight of the polylactic acid-based resin. % to 2% by weight, or such as 2% to 3% by weight. When the content of D-lactic acid satisfies the above range, it may be advantageous in terms of improving the stretching processability of the film.

The content of L-lactic acid is, for example, 80% to 99% by weight, such as 83% to 99% by weight, such as 85% to 99% by weight, such as 95% to 95% by weight, based on the total weight of the polylactic acid-based resin. 99 wt%, such as 96 wt% to 99 wt%, such as 96 wt% to 98 wt%, or eg 96 wt% to 97 wt%. When the content of L-lactic acid satisfies the above range, it may be advantageous in terms of improving heat resistance properties of the film.

The polylactic acid-based resin may have a melting temperature (Tm) of 100 °C to 250 °C, 110 °C to 220 °C, or 120 °C to 200 °C.

The polylactic acid-based resin may have a glass transition temperature (Tg) of 30 °C to 80 °C, 40 °C to 80 °C, 40 °C to 70 °C, or 45 °C to 65 °C.

The polylactic acid-based resin has a melt viscosity (V _PLA ) at 210 ° C of, for example, 5,000 poise to 12,000 poise, for example 6,500 poise to 12,000 poise, for example 6,500 poise to 11,000 poise, for example 7,000 poise to 12,000 poise, for example 7,500 poise to 11,000 poise , or for example 8,000 poise to 10,000 poise. At this time, the melt viscosity can be measured using a rheometer (RDS).

According to an embodiment of the present invention, the content of the first resin including the polylactic acid-based resin is 50% by weight or more, 55% by weight or more, based on the total weight of the first resin and the second resin. 60% by weight or more. In addition, the content of the polylactic acid-based resin is 99% by weight or less, 97% by weight or less, 95% by weight or less, 93% by weight or less, 92% by weight or less based on the total weight of the first resin and the second resin. or less, 90% by weight or less, 85% by weight or less, or 80% by weight or less. Specifically, the first resin, based on the total weight of the first resin and the second resin, for example 50% to 97% by weight, for example 50% to 95% by weight, for example 50% to 92% by weight, for example 50% to 90% by weight, or eg 60% to 90% by weight.

When the content of the first resin is less than the above range, mechanical properties and optical properties such as haze may be deteriorated, and when the content of the first resin exceeds the above range, brittleness increases, Flexibility is reduced, so it is easy to break or break, noise may be increased, and thermal bonding strength may be reduced.

In particular, the first resin has a property that the film becomes hard when the use temperature range is 20 ° C or less due to its high brittleness. The film loses its elasticity and tends to become brittle, and its use is limited due to its high noise.

Therefore, in an embodiment, a second resin including a vinyl acetate-based resin is used along with the first resin so that flexibility, noise level, and thermal bonding strength can be simultaneously improved while maintaining excellent mechanical properties and optical properties such as transparency. It is characterized by including.

Specifically, since the vinyl acetate-based resin included in the second resin has excellent compatibility with the polylactic acid-based resin included in the first resin, it can be easily mixed with each other and have excellent bonding strength. It is possible to simultaneously improve flexibility, transparency, and noise level as well as increase thermal bonding strength.

The vinyl acetate-based resin has a glass transition temperature (Tg) of, for example, 0 ° C to 80 ° C, for example 0 ° C to 60 ° C, for example 0 ° C to 50 ° C, for example 0 ° C to 40 ° C, for example It may be, for example, 0 °C to 30 °C, such as 1 °C to 20 °C, or eg 1 °C to 10 °C.

The vinyl acetate-based resin may have a specific gravity of, for example, 0 to 2.0, eg 0 to 1.5, eg 0 to 1.2, eg 0.5 to 1.2, or eg 1.0 to 1.2.

The vinyl acetate-based resin has a melt index (MI) of, for example, 0 to 120 g/10 min, for example 0 to 100 g/10 min, for example 1 to 80 g/10 min, for example 5 to 100 g/10 min. 60 g/10 min, or for example 5 to 50 g/10 min. The melt index (MI) can be measured at a temperature of 100° C. and under a load of 2.16 kg according to ASTM D1238.

According to an embodiment, the vinyl acetate-based resin may include a vinyl acetate-vinyl laurate copolymer formed by copolymerizing vinyl acetate and vinyl laurate.

Since the vinyl acetate-vinyl laurate copolymer is a copolymer resin whose biodegradability has been certified according to ISO14855 or DIN 13432 standards, when the vinyl acetate-based resin includes the vinyl acetate-vinyl laurate copolymer, it is naturally degraded by microorganisms, etc. It is environmentally friendly because it can be decomposed, and it has excellent compatibility with the polylactic acid-based resin and has good bonding strength with the resin, so that the desired effect in the present invention can be easily achieved. For example, in the case of vinyl acetate-based resins such as ethylene vinyl acetate, the content of carboxyl groups is relatively high and the content of acetate acid is low, so compatibility with polylactic acid-based resins may deteriorate.

For example, when the biodegradable film includes only the first resin including the polylactic acid-based resin, Young's modulus increases, so flexibility may decrease and noise level may increase.

In addition, for example, when the second resin includes PBAT resin, which is a biodegradable resin other than the vinyl acetate-based resin, the haze may significantly increase and the thermal bonding strength may decrease, so that transparency and adhesiveness are required. There may be restrictions on the use of biodegradable films or packaging materials.

According to an embodiment, the content of vinyl laurate in the vinyl acetate-vinyl laurate copolymer may be important in order to further improve Young's modulus, noise level and thermal bonding strength while maintaining excellent mechanical properties and optical properties such as transparency. can

The content of vinyl laurate in the vinyl acetate-vinyl laurate copolymer is, for example, greater than 0 mol% and less than or equal to 20 mol%, such as greater than 0 mol% and less than or equal to 15 mol%, such as greater than 0 mol% and less than or equal to 20 mol%. 10 mol% or less, such as 1 mol% or more and 8 mol% or less, or eg 2 mol% or more and 5 mol% or less. When the content of vinyl laurate in the vinyl acetate-vinyl laurate copolymer satisfies the above range, Young's modulus and noise level can be lowered and thermal bonding strength can be improved, thereby improving flexibility, thermal bonding characteristics and noise level characteristics. can be improved If the content of vinyl laurate in the vinyl acetate-vinyl laurate copolymer is less than the above range, the effect desired in the present invention may be insignificant, and if it exceeds the above range, the surface transition of the vinyl acetate-based resin when pressurized (migration) may occur and the durability of the molded product may decrease, resulting in a decrease in quality. In addition, in the case of an acid having a short chain length such as vinyl butyrate or vinyl caprorate, durability may decrease at the same content.

In addition, in the biodegradable film according to the embodiment, in order to realize excellent mechanical properties and optical properties such as transparency, while maximizing flexibility and thermal bonding strength and lowering the noise level, the vinyl acetate system included in the biodegradable film The content of the second resin containing resin is very important.

According to an embodiment of the present invention, the second resin, based on the total weight of the first resin and the second resin, 1% by weight or more, 3% by weight or more, 5% by weight or more, 7% by weight or more, 8 wt% or more, 10 wt% or more, 15 wt% or more, or 20 wt% or more. In addition, the second resin may be included in an amount of 50% by weight or less, 45% by weight or less, or 40% by weight or less based on the total weight of the biodegradable film. Specifically, the second resin, based on the total weight of the first resin and the second resin, for example 1% to 50% by weight, for example 3% to 50% by weight, for example 5% to 50% by weight, for example 10% to 50% by weight, or eg 10% to 40% by weight.

When the content of the second resin exceeds the above-described range, mechanical properties and optical properties may be deteriorated, and when the content of the second resin is less than the above-described range, brittleness increases and flexibility is reduced to break or It is easy to break, noise can be severe, and the strength of thermal bonding can be reduced.

According to embodiments, the mixed weight ratio of the first resin and the second resin is 50 to 97:3 to 50, such as 50 to 95:5 to 50, such as 50 to 90:10 to 50, such as 60 to 90:10 to 40, such as 65 to 85: 15 to 35, or eg 60 to 80: 20 to 40. When the mixed weight ratio of the first resin and the second resin satisfies the above range, flexibility and thermal bonding strength may be improved while having appropriate strength and haze, and noise level may be reduced.

On the other hand, the biodegradable film according to an embodiment of the present invention comprises an aliphatic polyester-based resin or an aliphatic-aromatic co-polyester-based resin different from that used in the first resin, in addition to the first resin and the second resin. 3 resins may be further included.

According to an embodiment of the present invention, the aliphatic polyester-based resin or aliphatic-aromatic copolymerized polyester-based resin is, for example, a polybutylene adipate terephthalate (PBAT) resin, a polybutylene succinate (PBS) resin, Polybutylene adipate (PBA) resin, polybutylene succinate-adipate (PBSA) resin, polybutylene succinate-terephthalate (PBST) resin, polyhydroxybutylate-valerate (PHBV) resin, poly It may include at least one selected from the group consisting of a caprolactone (PCL) resin and a polybutylene succinate adipate terephthalate (PBSAT) resin. Specifically, the aliphatic polyester-based resin or aliphatic-aromatic co-polyester-based resin is, for example, polybutylene adipate terephthalate (PBAT) resin, polybutylene succinate (PBS) resin, and polybutylene adipate. It may include at least one selected from the group consisting of paint (PBA) resins.

More specifically, the aliphatic polyester-based resin may include, for example, at least one selected from the group consisting of polybutylene succinate (PBS) resin and polybutylene adipate (PBA) resin, for example, polybutylene Len succinate (PBS) resin may be included. In addition, the aliphatic-aromatic co-polyester-based resin may include at least one selected from the group consisting of polybutylene adipate terephthalate (PBAT) resin and polybutylene succinate-terephthalate (PBST) resin, For example, polybutylene adipate terephthalate (PBAT) resin may be included.

The third resin is, for example, greater than 0 wt% to 20 wt% or less, for example 1 wt% or more to 15 wt% or less, or for example 1 wt% or more to 15 wt% or less based on the total weight of the biodegradable film. It may be included in 10% by weight or less.

In addition, according to an embodiment of the present invention, the polyester film is one selected from the group consisting of a conventional electrostatic agent, antistatic agent, antioxidant, heat stabilizer, sunscreen, antiblocking agent, impact resistance reinforcing agent, and other inorganic lubricants The above additives may be further included. The above additives may be added within a range not impairing the effects of the present invention.

The thickness of the biodegradable film is 5 μm to 100 μm, 7 μm to 80 μm, eg 8 μm to 50 μm, eg 10 μm to 50 μm, eg 10 μm to 40 μm, or for example It may be 10 μm to 30 μm.

According to one embodiment, the biodegradable film, referring to FIG. 2, one side of the biodegradable film having a width (W) of 75 mm and a length (L) of 150 mm and one side of a polylactic acid (PLA) film at 100 ° C. After thermal bonding to each other at 1.5 bar for 1 second, cut to a width interval of 15 mm, and mount the center 3 pieces to a universal testing machine (UTM) so that the chuck interval is 50 mm, excluding the sample (X) at both ends, The thermal bonding strength (AS) when peeling at a peeling angle of 180 ° and a peeling speed of 200 mm / min is measured and the average value is taken as a thermal bonding strength of 4 N / 15 mm or more. The thermal adhesive strength (AS) of the biodegradable film is, for example, 5 N/15mm or more, eg 6 N/15mm or more, eg 8 N/15mm or more, eg 10 N/15mm or more, or For example, it may be greater than or equal to 12 N/15 mm, specifically 4 N/15 mm to 30 N/15 mm, 5 N/15 mm to 25 N/15 mm, or 10 N/15 mm to 25 N/15 mm.

When the thermal bonding strength (AS) of the biodegradable film satisfies the above range, the thermal bonding property, in particular, the thermal bonding property with the same or similar substrate is excellent, and its utilization can be further increased.

On the other hand, according to another embodiment of the present invention, the biodegradable film has a low haze (haze) excellent transparency has the advantage that can be utilized in various applications requiring transparency.

Specifically, the haze of the biodegradable film may be 10% or less, 8% or less, 5% or less, 3% or less, 3% or less, 2.9% or less, or 2.8% or less. When the haze exceeds the above range, its use may be limited due to lack of transparency.

In addition, the biodegradable film may have excellent flexibility due to a low Young's modulus, and thus processability, formability, and productivity may be further improved.

The Young's modulus of the biodegradable film is 380 kgf/mm2 or less, 360 kgf/mm2 or less, 350 kgf/mm2 or less, 340 kgf/mm2 or less, 330 kgf/mm2 or less, 320 kgf/mm2 or less, 300 kgf/mm2 or less, 280 It may be kgf/mm2 or less, 270 kgf/mm2 or less, 260 kgf/mm2 or less, or 250 kgf/mm2 or less. Specifically, the Young's modulus of the biodegradable film is 100 kgf/mm2 to 380 kgf/mm2, 120 kgf/mm2 to 350 kgf/mm2, 150 kgf/mm2 to 300 kgf/mm2, 200 kgf/mm2 to 300 kgf/mm2, or It may be 230 kgf/mm2 to 300 kgf/mm2.

The Young's modulus is determined by making a biodegradable film specimen in accordance with ASTM D882, cutting it to a width of 15 mm and a length of 150 mm, mounting the specimen so that the gap between chucks is 50 mm, and using a tensile tester (Instron, 5566A) After testing at a tensile speed of 200 mm/min, it can be measured as a straight line slope value from the starting point of measurement to the point of reaching 2% elongation.

In general, in the case of a biodegradable film containing only a first resin containing a polylactic acid-based resin and not a second resin containing a vinyl acetate-based resin, the Young's modulus is greater than 380 kgf/mm2 and the flexibility is significantly reduced, making the film It is stiff and may limit its use. When the Young's modulus of the biodegradable film satisfies the above-mentioned range, flexibility is excellent, and various applications can be expanded, and processability, moldability, and productivity can be further improved.

In embodiments, the average noise level (N _AVG ) of the biodegradable film is, for example, 88 dB or less, such as 85 dB or less, such as 84 dB or less, such as 83 dB or less, such as 82 dB or less, such as 80 dB or less, such as 79.5 dB or less, or for example 78 dB or less.

In particular, when the average noise level (N _AVG ) of the biodegradable film satisfies the above range, there is an advantage in providing a high-quality packaging material due to a low noise level.

The average noise level (N _AVG ) of the biodegradable film is 650 (W) mm × 450 (D) mm × 500 (H) mm in a box made of polycarbonate, 210 mm × 297 mm of A4 Cut to size, place the biodegradable film 30 cm away from a digital noise analyzer (Cirrus Research PLC, model name: CR-162C), hold both ends of the film with a jig, and back and forth at a rate of 30 times/min. The average noise level calculated by measuring the noise level 5 times was defined as the noise level measured when the twist was repeated for more than 5 seconds.

The biodegradable film may have a soft noise composite factor (FNC) of 14 to 32 represented by Equation 1 below:

In Equation 1 above,

The YM is made of a biodegradable film specimen in accordance with ASTM D882, cut to a width of 15 mm and a length of 150 mm, mounted so that the gap between chucks is 50 mm, and tested at a tensile speed of 200 mm/min, from the starting point of measurement Young's modulus (kgf/㎟), which is the value of the straight line slope until the elongation reaches 2%, and is a value excluding units,

The N _AVG is a biodegradable film cut to A4 size of 210 mm × 297 mm in a box of 650 (W) mm × 450 (D) mm × 500 (H) mm made of polycarbonate from a digital noise analyzer The average noise level (dB) calculated by measuring the maximum noise level measured 5 times by placing it at a distance of 30 cm and holding both ends of the film with a jig and twisting it back and forth at a rate of 30 times/min repeatedly to generate noise for more than 5 seconds ), is a numerical value excluding units.

The flexible noise composite factor (FNC) represented by Equation 1 is represented by dividing the value of the product of the Young's modulus and the noise level of the biodegradable film by 1000, which is an index representing the degree of composite characteristics of the flexibility and noise level of the biodegradable film. can be

The flexible noise complexity (FNC) may be lower as the Young's modulus and/or noise level of the biodegradable film is lower within the above range.

When the flexible noise complex (FNC) having these characteristics satisfies the specific range, the flexibility and transparency of the biodegradable film can be further improved, the noise level can be reduced, and furthermore, packaging materials including the biodegradable film The quality of molded products can be further improved.

The biodegradable film has a soft noise composite factor (FNC) of, for example, 14 to 32, for example 14 to 31, for example 14 to 30, for example 14 to 29, for example 14 to 26, for example eg 14 to 22, eg 14 to 20, or eg 15 to 18. When the flexible noise complexity (FNC) satisfies the above range, flexibility and noise characteristics of the biodegradable film may be simultaneously improved.

In addition, the biodegradable film may have an adhesion index (AI) of 30% or more compared to noise improvement represented by Equation 2 below,

In Equation 2 above,

In the AS, one side of a biodegradable film specimen having a width of 15 mm and a length of 150 mm and one side of a polylactic acid (PLA) film are thermally bonded to each other at 100 ° C and 1.5 bar for 1 second, and then placed in a universal testing machine (UTM) at a distance between chucks of 50 In the thermal bonding strength (N/15mm) when peeling at a peeling angle of 180 ° and a peeling speed of 200 mm / min by mounting so as to be mm, it is a value excluding units,

ΔN is a degree of noise improvement represented by Equation 2-1 below, and is a numerical value excluding units,

<Equation 2-1> Noise improvement (ΔN, dB) = N ₁ - N _B

In Equation 2-1 above,

The N ₁ is the average noise level (dB) of the biodegradable film containing 100% by weight of the first resin,

The N _B is the average noise level (dB) of the biodegradable film including the mixed resin of the first resin and the second resin,

The average noise level (dB) is obtained by digitally measuring a biodegradable film cut to A4 size of 210 mm × 297 mm in a box of 650 (W) mm × 450 (D) mm × 500 (H) mm made of polycarbonate. It is located 30 cm away from the noise analyzer, holds both ends of the film with a jig, and twists back and forth at a rate of 30 times/min to repeat the maximum noise level measured when making noise for more than 5 seconds. Calculated by measuring 5 times .

The noise improvement versus adhesion index (AI) represented by Equation 2 means the ratio of the noise improvement (ΔN) to the thermal bonding strength (AS) of the biodegradable film.

Specifically, the noise improvement (ΔN) of the biodegradable film is the average noise level (dB) (N ₁ ) of the biodegradable film containing 100% by weight of the first resin, the mixed resin of the first resin and the second resin The difference (decrease) in the average noise level (dB) (N _B ) of the biodegradable film containing the biodegradable film containing the mixed resin of the first resin and the second resin represents the degree of improvement in noise level. In addition, this noise improvement is very closely related to flexibility and can be seen as an increase in flexibility. Therefore, since the noise improvement (ΔN) versus adhesion index (AI) of the biodegradable film represented by Equation 2 may mean the thermal bonding strength per flexibility improvement amount, the thermal bonding strength, noise level and It can be an indicator of the degree of complex characteristics of flexibility.

The adhesion index (AI) of the biodegradable film is, for example, 50% or more, such as 70% or more, such as 80% or more, such as 100% or more, such as 110% or more, For example, it may be 112% or more, such as 114% or more, or, for example, 120% or more, specifically 30 to 200%, 50 to 200%, 60 to 180%, 80 to 160%, or 85 to 150%. may be %.

When the adhesive index (AI) compared to the noise improvement of the biodegradable film satisfies the above range, the thermal bonding strength of the biodegradable film may be further improved and the noise level may be improved, and furthermore, a packaging material including the biodegradable film. It is possible to further improve the quality of a molded product such as the etc. and adhesive properties such as sealing property.

In Equation 2, the noise improvement (ΔN) of the biodegradable film is, for example, 1 dB or more, for example 2 dB or more, for example 3 dB or more, for example 4 dB or more, for example 5 dB or more, or for example 10 dB or more.

When the noise improvement (ΔN) of the biodegradable film satisfies the above range, it may be more advantageous to achieve the desired effect in the present invention.

In addition, the biodegradable film may have an improvement in thermal bonding strength (ΔAS) of 0.5 N/15 mm or more represented by Equation 2-2 below:

In Equation 2-2 above,

AS ₁ is the thermal bonding strength (N/15mm) of the biodegradable film containing 100% by weight of the first resin,

AS _B is the thermal bonding strength (N/15 mm) of the biodegradable film including the mixed resin of the first resin and the second resin.

That is, the biodegradable film has a thermal bonding strength improvement (ΔAS) of the first resin and the second resin in the thermal bonding strength (N/15mm) (AS ₁ ) of the biodegradable film containing 100% by weight of the first resin. Degree of improvement in thermal bonding strength of the biodegradable film including the mixed resin of the first resin and the second resin as the difference (increment) of the thermal bonding strength (N/15mm) (AS _B ) of the biodegradable film comprising the mixed resin of indicates

The biodegradable film has an improvement in thermal bonding strength (ΔAS) of, for example, 1 N/15 mm or more, 3 N/15 mm or more, 4 N/15 mm or more, eg 5 N/15 mm or more, For example, it may be 6 N/15 mm or more, 7 N/15 mm or more, 8 N/15 mm or more, or 9 N/15 mm or more. The biodegradable film has a greater thermal bonding strength improvement effect as the value of the thermal bonding strength improvement (ΔAS) increases, so that the quality of molded products such as packaging materials including the biodegradable film and adhesive properties such as sealing properties can be further improved. there is.

In addition, the biodegradable film may have ΔT of 2.0 or more represented by Equation 2-3 below:

In Equation 2-3 above,

ΔAS and ΔN are as described above, respectively, and are numerical values excluding units.

The ΔT is the sum of the thermal bonding strength improvement (ΔAS) and the noise improvement (ΔN) of the biodegradable film, and may mean the total improvement effect of thermal bonding strength and noise improvement of the biodegradable film.

Specifically, ΔT is eg 2.5 or higher, eg 3.0 or higher, eg 3.5 or higher, eg 4.0 or higher, eg 4.5 or higher, eg 5.0 or higher, eg 6.0 or higher, for example 8.0 or higher, eg 10.0 or higher, eg 12.0 or higher, or eg 15.0 or higher.

When ΔT satisfies the above range, effects of improving thermal bonding strength and noise level may be simultaneously improved.

Furthermore, the biodegradable film may have an ASPN of 0.05 to 3 represented by Formula 2-4 below:

In Equation 2-4 above,

The ASPN is biodegradable of the film It is the noise improvement degree (ΔN) versus the thermal bonding strength improvement degree (ΔAS). In addition, since the noise improvement is closely linked to the improvement of flexibility, it is more advantageous to provide a high-quality packaging material when the degree of adhesion improvement per flexibility improvement satisfies an appropriate range, and has the advantage of being able to expand various applications.

Specifically, the ASPN is for example 0.05 to 2.5, for example 0.1 to 2.5, for example 0.3 to 2.5, for example 0.5 to 2.0, for example 0.6 to 1.6, for example 0.6 to 1.5, or for example For example, it may be 0.7 to 1.3.

When the ASPN satisfies the above range, the thermal bonding strength improvement per flexibility improvement effect is excellent.

Furthermore, the biodegradable film may have a quality composite index (QCI) of less than 37 represented by Equation 3 below:

In Equation 3 above,

The HZ is a value excluding units measured as haze (%) of the biodegradable film, and the FNC is a soft noise composite, as described above.

The quality composite index (QCI) of the biodegradable film may be, for example, 35 or less, 33 or less, 32 or less, 30 or less, 28 or less, 27 or less, 25 or less, or 24 or less, 3 or more, 5 or more, or 10 or more. , or 15 or more.

The quality complex index (QCI) represented by Equation 3 is the sum of the soft noise complexity and haze of the biodegradable film, and is an index representing the degree of complex characteristics of the biodegradable film such as flexibility, noise level, and transparency.

The quality complex index (QCI) may satisfy the above range as all of the flexibility, transparency and noise characteristics of the biodegradable film are excellent. In addition, the quality complex index (QCI) may be more advantageous as haze, Young's modulus and/or noise level of the biodegradable film are lower, respectively, within the above range.

When the quality complex index (QCI) having these characteristics satisfies the above-described range, the flexibility and transparency of the biodegradable film can be further improved at the same time, the noise level can be reduced, and further, packaging materials including the biodegradable film, etc. The quality of molded products can be further improved.

The biodegradable film of the present invention may have a biodegradation rate of at least 60% or more, preferably 80% or more, and more preferably 90% or more in view of the nature of the product to reduce the environmental load.

The composition and physical properties of the biodegradable film according to the embodiment can be efficiently achieved by manufacturing the biodegradable film according to the embodiment.

Hereinafter, a method for producing the biodegradable film will be described in detail.

[생분해성 필름의 제조방법][Method of manufacturing biodegradable film]

According to one embodiment, preparing a sheet by mixing a first resin including a polylactic acid-based resin and a second resin including a vinyl acetate-based resin and then melt-extruding them (step 1); preparing a film by stretching the melt-extruded sheet (step 2); It provides a method for producing a biodegradable film comprising a; and heat-setting the stretched film (step 3).

In the method for manufacturing a biodegradable film according to an embodiment of the present invention, a first resin and a second resin containing a specific resin as a main component are melt-extruded to prepare a sheet, and by stretching and heat-setting, formability and processability are improved. And productivity can be further improved, and a film with low noise level can be obtained while simultaneously having excellent adhesive properties, flexibility and transparency aimed at in the present invention in an economical and efficient way.

In particular, in the method for manufacturing the biodegradable film, by controlling the content of the second resin within a specific range, the thermal bonding strength of the biodegradable film can be adjusted beyond a specific range while maintaining excellent mechanical and optical properties, and flexibility And there is a technical significance in that it can improve noise characteristics at the same time.

Referring to FIG. 1, the biodegradable film manufacturing method (S100) is to prepare a sheet by mixing a first resin including a polylactic acid-based resin and a second resin including a vinyl acetate-based resin and then melting and extruding the same. Step S110 may be included.

Descriptions related to the polylactic acid-based resin and the vinyl acetate-based resin included in the first resin and the second resin are as described above.

In addition, according to an embodiment of the present invention, when the content of the second resin is adjusted to 3% by weight or more based on the total weight of the first resin and the second resin, the thermal bonding property is more excellent, The flexibility, transparency, and noise level of the biodegradable film can be further improved.

In addition, according to the intended use and physical property design, a third resin and additives may be further added in addition to the first resin and the second resin, and the third resin and additives are as described above.

According to one embodiment of the present invention, the first resin and the second resin may be mixed and melt-extruded to form a sheet. In addition, biodegradable pellets (blended chips) may be obtained by mixing and extruding the first resin and the second resin, and biodegradable sheets and films may be obtained using the same.

In addition, the melt extrusion temperature may be, for example, greater than 180 °C to 250 °C, such as 190 °C to 240 °C, or, for example, 190 °C to 230 °C. The extrusion may be performed using a twin screw extruder or a single screw extruder.

Also, according to an embodiment, drying the first resin and the second resin may be further included before the melt extrusion. The drying step may be performed at, for example, 40 °C to 130 °C, or 80 °C to 90 °C for 4 to 24 hours.

On the other hand, the method for producing the biodegradable film (S100) may include a step (S120) of preparing a film by stretching the melt-extruded sheet.

Specifically, the melt-extruded sheet may be biaxially stretched, and the biaxially stretched step may include, for example, preheating to 50°C to 80°C, followed by longitudinal stretching 2 to 4 times in the machine direction (MD) at 40°C to 100°C. and transverse stretching 3 to 6 times in the transverse direction (TD) at 50° C. to 150° C.

By biaxially stretching the melt-extruded sheet in both directions, the physical properties and formability of the biodegradable film can be further improved, so that a high-quality packaging material can be realized.

If, in the case of uniaxial stretching in only one direction of the machine direction and the transverse direction, the thickness deviation of the biodegradable film is severe, the strength of the non-stretched side may be lowered, and the thermal properties may also be lowered.

The manufacturing method of the biodegradable film (S100) may include a step of heat-setting the stretched film (S130).

In addition, the heat setting step may be performed at 50 °C to 150 °C, 70 °C to 150 °C, 100 °C to 150 °C, or 110 °C to 140 °C.

When the biodegradable film is manufactured according to the manufacturing method of the embodiment, it is economical and efficient, and it may be more effective to manufacture a biodegradable film having desired configuration and physical properties.

[친환경 포장재][Eco-friendly packaging]

According to one embodiment, the present invention may provide an eco-friendly packaging material including the biodegradable film.

Specifically, the eco-friendly packaging material includes a biodegradable film, and the biodegradable film includes a first resin including a polylactic acid-based resin; and a second resin including a vinyl acetate-based resin.

In addition, the biodegradable film is obtained by thermally bonding one side of a biodegradable film specimen having a width of 15 mm and a length of 150 mm and one side of a polylactic acid (PLA) film at 100° C. and 1.5 bar for 1 second, and then attaching the same to a universal testing machine (UTM). ), the thermal bonding strength (N/15mm) when peeling at a peeling angle of 180 ° and a peeling speed of 200 mm/min may be 4 N/15mm or more.

The eco-friendly packaging material may be in the form of a film that can be used, for example, as a general disposable packaging material and food packaging material, and may be in the form of a fiber that can be used as a fabric, knitted fabric, non-woven fabric, rope, etc. It may be in the form of a container that can be used as a container for packaging food.

The eco-friendly packaging material may provide excellent physical properties and quality by including a biodegradable film having excellent thermal bonding strength, flexibility and transparency, and low noise level. In addition, since it is biodegradable and can be completely decomposed upon landfill to provide a packaging material having environmentally friendly properties, it can be used in various fields as a packaging material and exhibit excellent properties.

The present invention will be described in more detail by the following examples. The following examples are merely illustrative of the present invention, and the scope of the present invention is not limited thereto.

<실시예><Example>

Example 1

Manufacture of biodegradable film

As the first resin, a polylactic acid resin (Nature Works LLC, 4032D) having a D-lactide content of about 1.4% and a melt viscosity of about 8,770 poise at about 210 ° C., and a vinyl laurate content as the second resin A mixed resin was prepared by mixing 4 mol% of a vinyl acetate-vinyl laurate copolymer (VAc-VL) (Vinnex 8880, Wacker) based on the total content of the vinyl acetate-vinyl laurate copolymer. At this time, the mixing of the first resin and the second resin was performed so that the weight ratio of the first resin and the second resin of the final film was 90:10, as shown in Table 1 below.

After melt-extruding the mixed resin through an extruder having a temperature of 210° C., it was brought into close contact with a cooling roll cooled to 20° C. to obtain a sheet.

The unstretched biodegradable sheet thus obtained was stretched 3 times in the longitudinal direction at about 65 ° C and 4 times in the transverse direction at 85 ° C, and then the stretched sheet was heat-set at 140 ° C in the heat treatment section of the tenter to obtain a biodegradable sheet having a thickness of 20 μm. A film was made.

Examples 2 to 7

As shown in Table 1 below, a biodegradable film was prepared in the same manner as in Example 1, except that the weight ratio of the first resin and the second resin contained in the final biodegradable film was changed.

Comparative Example 1

As shown in Table 1 below, a biodegradable film was prepared in the same manner as in Example 1, except that only the first resin, which is a polylactic acid-based resin, was used.

Comparative Example 2

As shown in Table 1 below, a biodegradable film was prepared in the same manner as in Example 2, except that polybutylene adipate terephthalate (PBAT) resin was used instead of the vinyl acetate-vinyl laurate copolymer as the second resin. was manufactured.

evaluation example

After measuring the physical properties and evaluating the performance of the biodegradable films prepared according to the Examples and Comparative Examples in the following manner, the results are shown in Table 1 below.

Evaluation Example 1: Haze (HZ)

It was measured according to the ASTM D1003 standard using a Hazemeter (model name: SEP-H) of Nihon Semitsu Kogaku.

Evaluation Example 2: Young's modulus (YM)

After making the biodegradable film specimens prepared in Examples and Comparative Examples in accordance with ASTM D882, cut them into 15 mm wide and 150 mm long, and mount them so that the gap between chucks is 50 mm, and then the specimens are tested in a tensile tester (Instron 5566A) was used at a tensile speed of 200 mm/min, and then the straight line slope from the measurement start point to the elongation 2% reached was measured as Young's modulus (kgf/mm2).

Evaluation Example 3: Noise level (N _AVG )

The biodegradable films prepared in Examples and Comparative Examples were cut into an A4 size of 210 mm × 297 mm in a box of 650 (W) mm × 450 (D) mm × 500 (H) mm made of polycarbonate, and , Place the biodegradable film 30 cm away from the digital noise analyzer (Cirrus Research PLC, model name: CR-162C), grab both ends of the film with a jig and twist it back and forth at a rate of 30 times/min. The noise level measured when making noise for more than 5 seconds was measured 5 times and calculated.

Evaluation Example 4: Thermal bonding strength (AS)

Referring to FIG. 2, one side of a biodegradable film having a width of 75 mm and a length of 150 mm and one side of a polylactic acid (PLA) film having a thickness of about 20 μm prepared in Examples and Comparative Examples were heated at 100° C. and 1.5 bar for 1 second. After thermal bonding to each other, it is cut so that the width interval is 15 mm (width 15 mm and length 150 mm), and the center 3 samples, excluding the samples at both ends, are mounted on the universal testing machine (UTM) so that the interval between chucks is 50 mm. The thermal bonding strength (AS) was measured when peeling at a peeling angle of 180 ° and a peeling speed of 200 mm / min, and the thermal bonding strength was measured when the average value thereof was taken.

Evaluation Example 5: Flexible Noise Complexity (FNC)

The flexible noise complexity (FNC) represented by the following formula 1 was calculated using the values of YM and N _AVG measured in Evaluation Examples 2 and 3:

In Equation 1 above,

The YM is a biodegradable film specimen made in accordance with ASTM D882, cut to a width of 15 mm and a length of 150 mm, mounted so that the gap between chucks is 50 mm, and tested at a tensile speed of 200 mm / min, Elongation from the starting point of measurement It is Young's modulus (kgf/㎟), which is the value of the straight line slope until reaching 2%, and is a numerical value excluding units.

The N _AVG is a biodegradable film cut to A4 size of 210 mm × 297 mm in a box of 650 (W) mm × 450 (D) mm × 500 (H) mm made of polycarbonate from a digital noise analyzer Average noise level (dB) calculated by measuring the maximum noise level measured 5 times when making noise for more than 5 seconds by placing it at a distance of 30 cm, holding both ends of the film with a jig and twisting it back and forth at a rate of 30 times/min repeatedly ), is a numerical value excluding units.

Evaluation Example 6: Adhesion index (AI) against noise improvement

Using the values of N _AVG and AS measured in Evaluation Examples 3 and 4, the noise improvement versus adhesion index (AI) represented by Equation 2 was calculated:

In Equation 2 above,

In Equation 2-1 above,

At this time, the AS may be measured in the same manner as in Evaluation Example 4.

Evaluation Example 7: Quality Composite Index (QCI)

The quality composite index (QCI) represented by Equation 3 below was calculated using the values of HZ and FNC measured in Evaluation Examples 1 and 5:

In Equation 3 above,

The HZ and the FNC are as defined in Evaluation Examples 1 and 5.

As can be seen in Table 1, the biodegradable films of Examples 1 to 7 including a polylactic acid (PLA)-based resin as the first resin and a vinyl acetate (VAc)-based resin as the second resin have haze, flexibility, Both noise level and thermal adhesion were excellent.

Specifically, the biodegradable films of Examples 1 to 7 have a haze of 1.7% to 3.6%, a Young's modulus of 220 kgf/mm2 to 356 kgf/mm2, a noise level of 84.8 dB or less, and a thermal bonding strength of 4 N/15mm. From the above, it can be seen that the overall improvement compared to the biodegradable films of Comparative Examples 1 and 2. Accordingly, it was confirmed that the composite properties of the biodegradable film are very excellent by satisfying the optimal ranges of the flexible noise composite (FNC), the noise improvement ratio adhesion index (AI), and the quality composite index (QCI).

In addition, it can be seen that the thermal bonding strength improvement (ΔAS) and noise improvement (ΔN) of the biodegradable films of Examples 1 to 7 are significantly increased compared to the biodegradable films of Comparative Examples 1 and 2. This is because the flexibility of the film increased due to the improvement in thermal bonding strength as well as the increase in noise improvement, so it can be seen that the thermal bonding strength, noise level and flexibility of the biodegradable films of Examples 1 to 7 increased in a complex manner.

On the other hand, in the case of the biodegradable film of Comparative Example 1 including only the polylactic acid-based resin as the first resin and not including the second resin, vinyl acetate-based resin, the Young's modulus was 384 kgf/mm2 and the noise level significantly increased to 88.3 dB. , In the case of Comparative Example 2 using the PBAT resin instead of the second resin, the vinyl acetate-based resin, the haze was very high at 25% and the thermal bonding strength was very low at 3 N/15mm, which significantly reduced the thermal bonding strength and haze. showed physical properties. Accordingly, in both Comparative Examples 1 and 2, complex physical properties such as flexible noise complexity (FNC), noise improvement versus adhesion index (AI), and quality composite index (QCI) exhibited values outside the optimal range.

Therefore, it can be seen that the biodegradable film according to the embodiment of the present invention is very suitable for packaging because it not only improves flexibility and noise level, but also has excellent sealing property due to improved adhesion.

[Description of code]

W: width

L: length

X: sample at both ends (excluded from thermal bonding strength measurement)

Claims

A first resin comprising a polylactic acid-based resin; and

A second resin comprising a vinyl acetate-based resin;

One side of a biodegradable film specimen with a width of 15 mm and a length of 150 mm and one side of a polylactic acid (PLA) film are thermally bonded to each other at 100 ° C and 1.5 bar for 1 second, and then placed in a universal testing machine (UTM) with a gap between chucks of 50 mm. A biodegradable film having a thermal bonding strength (N/15mm) of 4 N/15mm or more when peeled at a peeling angle of 180 ° and a peeling speed of 200 mm/min by mounting as much as possible.
According to claim 1,

A biodegradable film that satisfies at least one property selected from the following properties:

Haze (HZ) of 10% or less;

Young's modulus (YM) of 380 kgf/mm2 or less; and

Average noise level of less than 88 dB (N AVG ).
According to claim 1,

A biodegradable film having a soft noise complex (FNC) of 14 to 32, represented by the following formula 1:

In Equation 1 above,

The YM is made of a biodegradable film specimen in accordance with ASTM D882, cut to a width of 15 mm and a length of 150 mm, mounted so that the gap between chucks is 50 mm, and tested at a tensile speed of 200 mm/min, from the starting point of measurement Young's modulus (kgf/㎟), which is the value of the straight line slope until the elongation reaches 2%, and is a value excluding units,

The N AVG is a biodegradable film cut to A4 size of 210 mm × 297 mm in a box of 650 (W) mm × 450 (D) mm × 500 (H) mm made of polycarbonate from a digital noise analyzer The average noise level (dB) calculated by measuring the maximum noise level measured 5 times by placing it at a distance of 30 cm and holding both ends of the film with a jig and twisting it back and forth at a rate of 30 times/min repeatedly to generate noise for more than 5 seconds ), is a numerical value excluding units.
According to claim 1,

A biodegradable film having an adhesion index (AI) of 30% or more compared to noise improvement represented by Equation 2 below:

In Equation 2 above,

In the AS, one side of a biodegradable film specimen having a width of 15 mm and a length of 150 mm and one side of a polylactic acid (PLA) film are thermally bonded to each other at 100 ° C and 1.5 bar for 1 second, and then placed in a universal testing machine (UTM) at a distance between chucks of 50 In the thermal bonding strength (N/15mm) when peeling at a peeling angle of 180 ° and a peeling speed of 200 mm / min by mounting so as to be mm, it is a value excluding units,

ΔN is a degree of noise improvement represented by Equation 2-1 below, and is a numerical value excluding units,

In Equation 2-1 above,

The N 1 is the average noise level (dB) of the biodegradable film containing 100% by weight of the first resin,

The N B is the average noise level (dB) of the biodegradable film including the mixed resin of the first resin and the second resin,

The average noise level (dB) is obtained by digitally measuring a biodegradable film cut to A4 size of 210 mm × 297 mm in a box of 650 (W) mm × 450 (D) mm × 500 (H) mm made of polycarbonate. It is located 30 cm away from the noise analyzer, holds both ends of the film with a jig, and twists back and forth at a rate of 30 times/min to repeat the maximum noise level measured when making noise for more than 5 seconds. Calculated by measuring 5 times .
According to claim 3,

A biodegradable film having a quality composite index (QCI) of less than 37 represented by Equation 3 below:

In Equation 3 above,

The HZ is a value excluding units measured as haze (%) of the biodegradable film,

The FNC is as defined in claim 3.
According to claim 1,

The content of the second resin is 3% by weight or more based on the total weight of the first resin and the second resin, the biodegradable film.
According to claim 1,

The vinyl acetate-based resin includes a vinyl acetate-vinyl laurate copolymer,

The content of vinyl laurate in the vinyl acetate-vinyl laurate copolymer is greater than 0 mol% and less than 20 mol%, biodegradable film.
preparing a sheet by mixing a first resin including a polylactic acid-based resin and a second resin including a vinyl acetate-based resin and then melting and extruding the mixture (step 1);

preparing a film by stretching the melt-extruded sheet (step 2); and

A method for producing a biodegradable film comprising the step of heat-setting the stretched film (step 3).
Including a biodegradable film,

The biodegradable film may include a first resin including a polylactic acid-based resin; and

An eco-friendly packaging material comprising a second resin comprising a vinyl acetate-based resin.