KR20240091675A - Biodegradable composition for coating and film comprising the same - Google Patents

Abstract

This specification discloses a coating composition that combines surface-modified cellulose and polyvinyl alcohol and has excellent oxygen and moisture barrier properties and is transparent, and a film using the same. The present disclosure is environmentally friendly because it is biodegradable by using cellulose, a biodegradable biomass, and has excellent barrier performance, so it can be widely used as a packaging material in various industrial fields such as food and pharmaceutical materials.

Description

Biodegradable composition for coating and film comprising the same}

This specification discloses a biodegradable coating composition, a film containing the same, and a method for manufacturing the same.

Packaging materials used for products in various industries such as food, electrical and electronic component materials, etc. must have the function of protecting products from external stimuli and maintaining hygiene and quality during transportation and storage, so they are easy to process and provide excellent oxygen and moisture blocking. Characteristics such as properties and chemical resistance are required. Polyethylene (PE) and polypropylene (PP), which are representative commercially available film materials, cause environmental pollution because they take a long time, from about 50 to over 1,000 years, to completely decompose. Additionally, as a material based on petroleum, there are limits to sustainability due to resource depletion. Conventionally, in the case of a coating layer for application to packaging materials, a metal thin film layer deposited with a halogenated polymer such as poly(vinyliden chloride) (PVDC) or a metal such as aluminum was used. However, these materials generate gases harmful to the human body during the incineration process or are opaque, making it difficult to visually check the contents. Therefore, there is a need to develop a coating layer that is biodegradable and satisfies excellent oxygen and moisture barrier properties and high transparency, as well as packaging materials containing the same.

Republic of Korea Patent Application Publication No. 10-2022-0077222

The problem that the present disclosure aims to solve is to provide a biodegradable and environmentally friendly coating composition and a film containing the same.

The problem to be solved by the present disclosure is to provide a coating composition having excellent oxygen and moisture barrier properties and a film containing the same.

The problem that the present disclosure aims to solve is to provide a film whose contents can be confirmed with high transparency.

One embodiment of the present disclosure provides a biodegradable coating composition containing dialdehyde cellulose (DAC) and polyvinyl alcohol (PVA).

Another embodiment of the present disclosure includes a base layer; and a coating layer containing dialdehyde cellulose (DAC) and polyvinyl alcohol (PVA) located on at least one side of the base layer.

Another embodiment of the present disclosure provides a packaging material including the biodegradable film.

Another embodiment of the present disclosure is a method of manufacturing the biodegradable film,

Coating a coating composition containing dialdehyde cellulose (DAC) and polyvinyl alcohol (PVA) on at least one side of the base layer; and

Drying the coated composition;

It provides a manufacturing method including.

One embodiment of the present disclosure can provide a transparent coating composition with excellent oxygen and water vapor barrier properties by combining dialdehyde cellulose, which is surface-modified cellulose, and polyvinyl alcohol, and a film using the same. Therefore, the present disclosure is environmentally friendly because it is biodegradable by using cellulose, a biodegradable biomass, and has excellent barrier performance, so it can be used as a packaging material in various industrial fields such as food and pharmaceutical materials where the inflow of oxygen and moisture must be blocked. Can be used widely.

FIG. 1 shows a cross-sectional structure of a film 100 including a coating layer 110 and a base layer 120 according to an embodiment of the present disclosure.
FIG. 2 shows a cross-sectional structure of a film 100 including a coating layer 110, a metal oxide layer 130, and a base layer 120 according to an embodiment of the present disclosure.
Figure 3 is a diagram showing the results of analyzing the content of aldehyde contained in dialdehyde cellulose (DAC) according to an embodiment of the present disclosure.
Figure 4 is a schematic diagram showing a coating method used to manufacture a film according to an embodiment of the present disclosure.
Figure 5 shows the biodegradability test report of the film prepared in Example 3 of Test Example 2.
Figure 6 shows the biomass content analysis test report of the film prepared in Example 3 of Test Example 3.
Figure 7 shows the cytotoxicity test report of the film prepared in Example 3 of Test Example 4.

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the attached drawings.

The embodiments of the present disclosure disclosed in the text are illustrative only for illustrative purposes, and the embodiments of the present disclosure may be implemented in various forms and should not be construed as limited to the embodiments described in the text. . The present disclosure can be subject to various changes and may take various forms. The embodiments are not intended to limit the present disclosure to a specific disclosed form, and all changes, equivalents, or substitutes included in the spirit and technical scope of the present disclosure are included. It should be understood as including.

Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and one or more other features The presence or addition of elements, numbers, steps, operations, components, parts or combinations thereof is not excluded.

In the present disclosure, the term “biodegradability” refers to biological activity that can be easily decomposed by microorganisms such as bacteria or bacteria, enzymes, etc.

One embodiment of the present disclosure may provide a biodegradable coating composition containing dialdehyde cellulose (DAC) and polyvinyl alcohol (PVA).

As an example, the dialdehyde cellulose (DAC) is cellulose surface-modified with an aldehyde group, and may contain an aldehyde content of 1.5 to 8 mmol/g. Specifically, the aldehyde content of the dialdehyde cellulose is 1.5 mmol/g or more, 2 mmol/g or more, 3 mmol/g or more, 4 mmol/g or more, 5 mmol/g or more, 6 mmol/g or more, or 7 mmol/g. g or more, and may be 8 mmol/g or less, 7 mmol/g or less, 6 mmol/g or less, 5 mmol/g or less, 4 mmol/g or less, or 3 mmol/g or less. Specifically, the dialdehyde cellulose is oxidized using a functional catalyst, 2,2,6,6-tetramethyl-piperidin1-oxyl (TEMPO). It may be surface-modified by replacing the hydroxyl group contained in temperature-oxidized cellulose with an aldehyde group. At this time, substitution with the aldehyde group can be accomplished through iodine oxidation (periodate oxidation) reaction. The iodine oxidation reaction can convert the hydroxyl groups of C2 and C3 of TEMPO-oxidized cellulose to dialdehyde groups without side reactions.

While TEMPO-oxidized cellulose has three hydroxyl groups per unit and has high affinity for moisture, the dialdehyde cellulose according to an embodiment of the present disclosure replaces the hydroxyl group with an aldehyde group. It can provide low moisture permeability by lowering the affinity for moisture and increasing the bonding strength with polyvinyl alcohol.

As an example, the cellulose may be extracted from biomass, for example, from trees, plants, algae, bacteria, etc.

As an example, the dialdehyde cellulose may be in the form of nanofibers, which are fibers with a nano-sized thickness, microfibers, which are fibers with a micro-sized thickness, or nanocrystals, but the base layer As long as coating is possible, it is not limited to the above form and can all be included in the scope of the present disclosure.

As an example, the polyvinyl alcohol may be denatured polyvinyl alcohol or undenatured polyvinyl alcohol. The modified polyvinyl alcohol is, for example, modified polyvinyl substituted with at least one organic functional group such as a carboxyl group, silyl group, ester group, sulfonic acid group, acetate group, isocyanate group, methylol group, nitrile group, and acetoacetyl group. It could be alcohol. As an example, the modified polyvinyl alcohol may be a block copolymer or graft copolymer modified with a polymer such as urethane, acrylic, polyester, epoxy, or polypropylene.

As an example, the composition may include dialdehyde cellulose (DAC) and polyvinyl alcohol (PVA) at a weight ratio of 1-4:1. Specifically, the dialdehyde cellulose (DAC) is used in an amount of 100 parts by weight or more, 150 parts by weight, 200 parts by weight, 250 parts by weight, 300 parts by weight, or 350 parts by weight based on 100 parts by weight of polyvinyl alcohol (PVA). It may be included in more than 400 parts by weight, 350 parts by weight or less, 300 parts by weight or less, 250 parts by weight or less, 200 parts by weight or less, or 150 parts by weight or less. If dialdehyde cellulose is included in a small amount beyond the above ratio, biodegradability may be reduced, and if it is included in a large amount outside the above ratio, coating properties and durability may be reduced.

As an example, the composition may include 0.1 to 5% by weight of dialdehyde cellulose (DAC) based on the total weight of the composition. Specifically, the composition contains dialdehyde cellulose (DAC) in an amount of 0.1% by weight or more, 0.2% by weight or more, 0.3% by weight or more, 0.4% by weight or more, 0.5% by weight or more, 0.6% by weight or more, 0.7% by weight or more. It may include more than 5% by weight, more than 0.8% by weight, more than 0.9% by weight, more than 1% by weight, more than 2% by weight, more than 3% by weight, or more than 4% by weight, and less than 5% by weight, less than 4% by weight, 3% by weight or more. % by weight or less, 2% by weight or less, 1 weight% or less, 0.9 weight% or less, 0.8 weight% or less, 0.7 weight% or less, 0.6 weight% or less, 0.5 weight% or less, 0.4 weight% or less, 0.3 weight% or less, or 0.2 weight% or less. It may contain less than % by weight. If it is outside the above range, biodegradability and oxygen and moisture barrier properties may be reduced, or coating properties and durability may be reduced.

Additionally, as an example, the composition may include 0.01 to 2.5% by weight of polyvinyl alcohol (PVA) based on the total weight of the composition. Specifically, the composition contains polyvinyl alcohol (PVA) in an amount of 0.01% by weight or more, 0.1% by weight or more, 0.15% by weight or more, 0.2% by weight or more, 0.25% by weight or more, 0.3% by weight or more, 0.4% by weight or more. It may be included in more than % by weight, more than 0.5% by weight, more than 1% by weight, or more than 2% by weight, and less than 2.5% by weight, less than 2% by weight, less than 1% by weight, less than 0.9% by weight, less than 0.8% by weight, 0.7% by weight or less. It may include less than 0.6% by weight, less than 0.5% by weight, less than 0.4% by weight, less than 0.3% by weight, less than 0.2% by weight, or less than 0.1% by weight. If it is outside the above range, oxygen and moisture barrier properties may be reduced, or coating properties and durability may be reduced.

As an example, the composition may further include a solvent. As an example, the solvent may be a water-soluble solvent. Specifically, the solvent may be water. The water may be distilled water, for example. As another example, the solvent may further include a volatile solvent along with water to provide process efficiency and drying stability. For example, the volatile solvent may be alcohol. More specifically, the volatile solvent may include one or more selected from the group consisting of ethanol, propanol, n-propanol, iso-propanol, butanol, iso-butanol, and decyl alcohol. Since the volatile solvent is volatile and has a lower boiling point than water, it volatilizes and dries during the drying process performed after applying the composition to the base film and helps volatilize and dry water at the same time, thereby increasing the efficiency of the process and the dried gas. It can provide dry stability of the barrier layer.

As an example, the composition may further include one or more additives selected from the group consisting of crosslinking agents, surfactants, antifoaming agents, and UV absorbers, and the types of these are not limited as long as they are commonly used in the art.

One embodiment of the present disclosure can provide a biodegradable film using the coating composition. Specifically, in one embodiment, a base layer; and A biodegradable film can be provided, including a coating layer containing dialdehyde cellulose (DAC) and polyvinyl alcohol (PVA) located on at least one side of the base layer.

In the present disclosure, the “film” refers to a layer formed in a thin and flat form and is used in the broadest sense to include a plate, sheet, membrane, etc.

The attached Figures 1 and 2 illustrate exemplary forms of the present disclosure. When described with reference to FIGS. 1 and 2 , the film 100 according to one embodiment may include a coating layer 110 and a base layer 120. Alternatively, the film according to one embodiment may have a metal oxide layer 130 further formed between the coating layer 110 and the base layer 120.

The description of dialdehyde cellulose (DAC) according to one embodiment and the mixing ratio and content range of dialdehyde cellulose (DAC) and polyvinyl alcohol (PVA) are as described above.

As an example, the thickness of the coating layer may be 0.5 to 5 μm. Specifically, the thickness of the coating layer may be 0.5 μm or more, 1 μm or more, 2 μm or more, 3 μm or more, or 4 μm or more, and may be 5 μm or less, 4 μm or less, 3 μm or less, 2 μm or less, or 1 μm or less. there is. If the thickness is too thin (less than 0.5 μm), gas barrier properties may deteriorate, and if it is too thick (more than 5 μm), drying time increases and the amount of material required increases, which may reduce efficiency.

In one embodiment, the base layer is not limited as long as it is a film containing a biodegradable material, for example, polylactic acid (PLA), polypropylene (PP), polyethylene (PE) , polyvinyl alcohol (PVA), polyhydroxyalkanoates (PHA), polyethylene terephthalate (PET), poly(caprolactone), PCL, poly glycolic acid ( poly(glycolic acid, PGA), poly(lactidecaprolactone), PLCL, polybutylene succinate (PBS), polybutylene adipate-co-terephthalate terephthalate (PBAT), poly(lactic-co-glycolic acid (PLGA), polyhydroxyalkanoate (PHA), plant-derived natural polymers and animal-derived polymers. As an example, the polyhydroxyalkanoates (PHA) may include one or more biodegradable polymers selected from the group consisting of poly-beta-hydroxybutyrate. PHB), poly-beta-hydrolyvalerate (PHV), or PHB/PHV, a copolymer thereof, as an example, the plant-derived natural polymer may include cellulose, Examples include hemicellulose, pectin, lignin, starch, etc. As an example, the animal-derived natural polymer may include chitin derived from the shell of shrimp, crab, etc.

As an example, the thickness of the base layer is not limited thereto and may be adjusted depending on the type of base layer.

As an example, the film may further include a metal oxide layer between the base layer and the coating layer. Specifically, the type of metal of the metal oxide layer is not limited as long as it can provide barrier properties against oxygen or water vapor. For example, the metal oxide layer may include one or more of aluminum oxide and silicon oxide. The metal oxide layer may be manufactured separately like a metal foil and laminated within a film. However, as long as a thin layer with a certain thickness can be manufactured, such as plating or deposition, the manufacturing method is not limited and can be included.

As an example, the thickness of the metal oxide layer may be 10 to 500 nm. Specifically, the thickness of the metal oxide layer may be 10 nm or more, 50 nm or more, 100 nm or more, 150 nm or more, 200 nm or more, 250 nm or more, 300 nm or more, 350 nm or more, 400 nm or more, or 450 nm or more. , 500 nm or less, 450 nm or less, 400 nm or less, 350 nm or less, 300 nm or less, 250 nm or less, 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less. If the thickness is less than 10 nm, the gas barrier property is minimal, and if the thickness is thicker than 500 nm, flexibility may decrease and process time and material costs may increase, reducing efficiency. In one embodiment, the film may be used as a barrier for one or more of moisture and oxygen.

As an example, moisture barrier properties can be confirmed by barrier properties against water vapor. From the above perspective, the film according to one embodiment may satisfy one or more of oxygen permeability of 1 cc/m ² *day or less and water vapor permeability of 20 g/m ² *day or less. Specifically, the film may have an oxygen permeability of 1 cc/m ² *day or less under 1 atm conditions. More specifically, the film may have an oxygen permeability of 1 cc/m ² *day or less, 0.9 cc/m ² *day or less, or 0.8 cc/m ² *day or less. Additionally, as an example, the film may have a water vapor permeability of 20 g/m ² *day or less under 1 atm conditions. Specifically, the film is 20 g/m ² *day or less, 19 g/m ² *day or less, 18 g/m ² *day or less, 17 g/m ² *day or less, 16 g/m ² *day or less. , 15 g/m ² *day or less, 14 g/m ² *day or less, 13 g/m ² *day or less, 12 g/m ² *day or less, 11 g/m ² *day or less, or 10 g/m It can have a water vapor permeability of less than ² *day.

In one embodiment, the film may be transparent. Specifically, the light transmittance of the film may be 80% or more. More specifically, the light transmittance of the film may be 80% or more, 85% or more, 88% or more, 89% or more, or 90% or more. Additionally, according to one embodiment, the haze of the film may be 10% or less. Specifically, the haze of the film may be 10% or less, 9% or less, 8% or less, 7% or less, 6% or less, or 5% or less.

One embodiment of the present disclosure may provide a packaging material including any of the above-mentioned biodegradable films or a combination thereof. As an example, the use of the packaging material is not limited as long as it requires moisture or oxygen barrier properties. For example, it may be used for packaging food or medicine.

One embodiment of the present disclosure is a method of manufacturing a biodegradable film using any of the above or a combination thereof,

Coating a coating composition containing dialdehyde cellulose (DAC) and polyvinyl alcohol (PVA) on at least one side of the base layer; and

Comprising the step of drying the coated composition,

Manufacturing methods can be provided.

At this time, the configuration of each of the coating composition, base layer, and metal oxide layer is as described above.

As an example, the method may further include a method of preparing the coating composition. Specifically, the method for producing the coating composition is,

Dispersing oxidized cellulose in a solvent and then adding sodium peroxoate to perform iodine oxidation (periodate oxidation) to produce dialdehyde cellulose; and

Mixing the prepared dialdehyde cellulose with polyvinyl alcohol and a solvent;

may include.

In addition, as an example, the method of manufacturing the film may further include forming a metal oxide layer by depositing a metal oxide on the base layer before the coating step.

As an example, the coating step included in the film manufacturing method may be performed through a wet coating process. Specifically, the coating process is not particularly limited, but includes doctor-blade coating, bar coating, comma coating, gravure coating, and microgravure coating. It may be performed by coating, dip coating, spray coating, or slot die coating.

As an example, the drying temperature in the drying step may be 50 to 80°C. Specifically, the drying temperature may be 50°C or higher, 55°C or higher, 60°C or higher, 65°C or higher, 70°C or higher, or 75°C or higher, and may be 80°C or lower, 75°C or lower, 70°C or lower, 65°C or lower, 60°C or lower. It may be below ℃, below 55℃ or below 51℃.

As an example, the drying time in the drying step may be 10 seconds to 60 minutes, but is not limited thereto. Specifically, the drying time may be 10 seconds or more, 1 minute or more, 5 minutes or more, 10 minutes or more, 15 minutes or more, 20 minutes or more, 25 minutes or more, or 30 minutes or more, 60 minutes or less, 50 minutes or less, 40 minutes or less. It may be less than a minute, less than 30 minutes, less than 20 minutes, less than 10 minutes, or less than 1 minute.

Hereinafter, the present disclosure will be described in more detail through examples. These examples are only for illustrating the present disclosure, and it will be apparent to those skilled in the art that the scope of the present disclosure should not be construed as limited by these examples.

[Example 1]

Among the biodegradable materials used in the biodegradable coating composition according to an example of the present disclosure, dialdehyde cellulose (DAC) was prepared according to the method below.

TEMPO-oxidized cellulose nanofibers (T-CNF, 10 g, 27.27 wt%) purchased from Moorim P&P Co., Ltd. were dispersed in 1 L of distilled water (DI water), wrapped with foil, and then added with sodium periodate. , 10 g, 0.047 mmol) was added and reacted at room temperature for 42 hours while blocking light. Chemical formula 1 below shows the synthesis reaction formula of dialdehyde cellulose (DAC) through iodine oxidation reaction.

[Formula 1]

Next, in order to decompose and remove the sodium periodonate remaining after the reaction, an excessive amount of ethylene glycol was added and stirred for 3 hours. After filtering this mixture through a 500 mesh filter, the remaining unfiltered residue was washed with distilled water until pH reached 7, then dried in an oven at 100°C, and the concentration of the final product (DAC) obtained was checked.

In order to analyze the aldehyde content contained in the dialdehyde cellulose (DAC) prepared above, dialdehyde cellulose (0.1 g) was dispersed in 15 mL of distilled water and then titrated to pH 5 using hydrochloric acid. Hydroxylamine hydrochloride (2.5 g, 0.036 mmol) was dissolved in 30 mL of separate distilled water, and the total volume was adjusted to 50 mL while adjusting pH to 5 with 0.5M NaOH solution. 4 mL of the prepared hydroxylamine hydrochloride solution was added to the dispersed DAC solution and stirred at room temperature overnight to cause imine reaction. The aldehyde content in dialdehyde cellulose was confirmed by adjusting the HCl generated as the aldehyde in dialdehyde cellulose to oxime through the imine reaction to pH 5 by adding 0.01, 0.04, and 0.1M NaOH solutions. Formula 2 below shows the imine reaction equation and titration reaction equation for analyzing the content of aldehyde contained in the dialdehyde cellulose (DAC).

[Formula 2]

As a result, as shown in Figure 3, it can be confirmed that the hydroxyl group of the TEMPO-treated cellulose was replaced with an aldehyde group through the iodine oxidation reaction, and the content of aldehyde groups capable of combining with polyvinyl alcohol increased.

[Example 2]

A biodegradable coating composition according to an example of the present disclosure was prepared according to the method below.

Dialdehyde cellulose (DAC) and polyvinyl alcohol (manufacturer: Alfa Aesa, product name: 41240, MW 88000-90000) prepared in Example 1 were added to distilled water at 0.5% by weight and 0.25% by weight, respectively, based on the total weight of the composition. It was added and reacted with sufficient stirring to prevent lumps from forming, thereby preparing a coating composition. The chemical formula below shows the reaction formula between dialdehyde cellulose (DAC) and polyvinyl alcohol.

[Formula 3]

[Example 3]

A biodegradable film according to an example of the present disclosure was manufactured according to the method below.

First, a film was prepared in which an aluminum oxide layer was deposited on a polylactic acid (PLA) film as a base film by depositing aluminum using an evaporator in an oxygen atmosphere.

Next, as exemplarily shown in FIG. 4, the coating solution prepared in Example 2 was applied on the base film using a doctor-blade coater. Afterwards, the film was dried in an oven at 60°C for 10 to 15 minutes to finally prepare a biodegradable film ((DAC+PVA)-AlO _x /PLA).

[Comparative Example 1]

The same film as the film in which aluminum oxide was deposited on the polylactic acid (PLA) film used in Example 3 was prepared as Comparative Example 1 (AlO _x /PLA).

[Comparative Example 2]

A film (PVA-AlO _x /PLA) was prepared in the same manner as Example 3, except that the coating composition did not contain dialdehyde cellulose (DAC).

[Comparative Example 3]

A film ((CNF+PVA)-AlO _x /PLA) was prepared.

[Test Example 1]

In order to analyze the oxygen and moisture barrier properties of the film prepared in Example 3, the following experiment was performed.

First, the oxygen barrier property of the film was analyzed by measuring oxygen permeability according to the ASTM D3985 method. Specifically, the space between the chamber containing high-purity oxygen and the chamber without oxygen was sealed with the film of Example 3, and the amount of oxygen moved by nitrogen, a carrier gas, was converted into an electronic signal and measured by a coulometric sensor. At this time, the measurement temperature was 23°C and the measurement area was 10 cm ² .

The moisture barrier property of the film was analyzed by measuring water vapor permeability according to the ASTM F1249 method. Specifically, the space between the dry chamber and the wet chamber was sealed with the film of Example 3, moisture (water vapor) was moved to the opposite side of the measurement sample using nitrogen, a carrier gas, and the content was measured by converting it into an electronic signal. At this time, the measured temperature was 37.8°C, the relative humidity was 100%, and the measured area was 1 cm ² .

After performing the same experiment on Comparative Example 1 (AlO _x /PLA), Comparative Example 2 (PVA-AlO _x /PLA), and Comparative Example 3 ((CNF + PVA) -AlO _x /PLA), Overall, they are shown in the table below.

Oxygen Transmission Rate (OTR)
(cc/m ² ·day) Water vapor transmission rate (WVTR)
(g/m ² ·day) Comparative Example 1 (AlO _x /PLA) 112.4 29.6916 Comparative Example 2 (PVA-AlO _x /PLA) 0.73 30.4 Comparative Example 3 ((CNF+PVA)-AlO _x /PLA) 0.07 34.8 Example 3 ((DAC+PVA)-AlO _x /PLA) 0.76 9.6939

As a result, Comparative Examples 1 to 3 all had a water vapor transmission rate (WVTR) of about 30 g/m ^{2 ·} day, and the water vapor transmission rate (WVTR) of the polylactic acid film itself was about 500 g/ Considering that it is more than m ^{2 ·} day, the performance has improved, but it is still not suitable for use as a packaging material for food, etc. On the other hand, the film of Example 3 according to an embodiment of the present disclosure showed a significantly low water vapor permeability of 10 g/m ^{2 ·} day or less due to low affinity for water due to the bond between dialdehyde and polyvinyl alcohol. In addition, Example 3 also showed a very low oxygen permeability of less than 1 cc/m ² ·day, confirming that it can be usefully used as a packaging material in various industrial fields such as food and medicine.

[Test Example 2]

In order to analyze the biodegradability of the film prepared in Example 3, the following experiment was performed.

The biodegradability analysis was commissioned by the Korea Institute of Construction and Living Environment (KCL), a Korean certified testing agency, and the degree of decomposition in the soil was analyzed based on the amount of carbon dioxide released during biodegradation of the film using the ISO 14855-1 method.

Figure 5 is attached to the biodegradability test report of the film according to Example 3. As shown in the test report, about 41% of the film was biodegraded, showing a biodegradability of 42.29% compared to the standard material. Additionally, during observation, there was nothing unusual about the moisture content, color, or smell of the compost. This means that the film according to the present disclosure exhibits excellent biodegradability.

[Test Example 3]

In order to analyze the biomass content of the film prepared in Example 3, the following experiment was performed.

The biomass content of the film was analyzed using the ASTM D6866 method by requesting Beta Analytical Laboratories, a U.S. certified testing agency. This method is a biomass content analysis method using accelerator mass spectrometry (AMS), which analyzes radiocarbon in organic matter by taking advantage of the fact that biomass has radiocarbon ( ¹⁴ C), while fossil materials do not have radiocarbon. .

As a result, as shown in Figure 6, the film of Example 3 was found to have a biomass content of 100%. As a result, it can be confirmed that the present disclosure can provide an environmentally friendly film and packaging material using the same.

[Test Example 4]

In order to analyze the cytotoxicity of the film prepared in Example 3, the following experiment was performed.

The cytotoxicity evaluation of the film was conducted by the Korea Institute of Construction and Living Environment (KCL), a certified Korean testing agency, and analyzed according to the ISO 10993-5 method. Specifically, cell culture technology was used to analyze cytotoxicity, such as cell lysis and inhibition of cell growth, caused by raw materials.

As a result, as shown in Figure 7, the film of Example 3 was treated with the eluate after elution, and as a result of qualitative analysis, cell rounding and cell granulation abnormalities were not observed in the treated cells, indicating cytotoxic reactivity. It was shown to be "0", i.e. there was no cytotoxicity.

100: biodegradable film
110: coating layer
120: base layer
130: Metal oxide layer

Claims (20)

A biodegradable coating composition containing dialdehyde cellulose (DAC) and polyvinyl alcohol (PVA). The composition according to claim 1, comprising dialdehyde cellulose (DAC) and polyvinyl alcohol (PVA) in a weight ratio of 1 to 4:1. The composition of claim 1, wherein the dialdehyde cellulose has an aldehyde content of 2 to 8 mmol/g. Base layer; and
A coating layer containing dialdehyde cellulose (DAC) and polyvinyl alcohol (PVA) located on at least one side of the base layer;
A biodegradable film containing. The film according to claim 4, comprising dialdehyde cellulose (DAC) and polyvinyl alcohol (PVA) in a weight ratio of 1 to 4:1. The film according to claim 4, wherein the dialdehyde cellulose has an aldehyde content of 2 to 8 mmol/g. The method of claim 4, wherein the base layer is made of polylactic acid (PLA), polypropylene (PP), polyethylene (PE), polyvinyl alcohol (PVA), or polyhydroxyalkanoate. (polyhydroxyalkanoates, PHA), polyethylene terephthalate (PET), poly(caprolactone), PCL, poly(glycolic acid, PGA), poly(lactidecaprolactone) ), PLCL), polybutylene succinate (PBS), polybutylene adipate-co-terephthalate (PBAT), poly(lactic-co-glycolic acid) A film comprising at least one biodegradable polymer selected from the group consisting of (lactic-co-glycolic acid, PLGA), polyhydroxyalkanoate (PHA), plant-derived natural polymers, and animal-derived polymers. The film according to claim 4, further comprising a metal oxide layer between the base layer and the coating layer. The film according to claim 8, wherein the metal oxide layer is an aluminum oxide layer. The film according to claim 4, wherein the coating layer has a thickness of 0.5 to 5 μm. The film of claim 4, wherein the film is used as a barrier to one or more of moisture and oxygen. The film according to claim 4, wherein the film satisfies one or more of oxygen permeability of 1 cc/m ² *day or less and water vapor permeability of 20 g/m ² *day or less. The film according to claim 4, wherein the film has a light transmittance of 80% or more. A packaging material comprising the film of any one of claims 4 to 13. The packaging material of claim 14, wherein the packaging material is for packaging food or medicine. A method of producing the film of any one of claims 4 to 13,
Coating a coating composition containing dialdehyde cellulose and polyvinyl alcohol on at least one side of the base layer; and
Drying the coated composition;
Including, manufacturing method. The method of claim 16, wherein the manufacturing method is a method of manufacturing the coating composition,
Dispersing oxidized cellulose in a solvent and then adding sodium peroxoate to perform iodine oxidation (Periodate oxidation) to produce dialdehyde cellulose; and
Mixing the prepared dialdehyde cellulose with polyvinyl alcohol and a solvent;
A manufacturing method further comprising: The manufacturing method of claim 16, further comprising forming a metal oxide layer by depositing a metal oxide on the base layer before the coating step. The method of claim 16, wherein the coating in the coating step includes doctor-blade coating, bar coating, comma coating, gravure coating, and microgravure coating. ), a manufacturing method carried out by dip coating, spray coating or slot die coating. The method of claim 16, wherein the drying step,
drying temperature between 50 and 80°C; and
drying time from 10 seconds to 60 minutes;
A manufacturing method, which is carried out under conditions that satisfy one or more of the following.