KR102480210B1 - Eco-friendly degradable plastic film and packaging material comprising the same - Google Patents

Abstract

Provided is an eco-friendly degradable polymer film of which the surface is modified to be hydrophobic and which can be widely applied in real life. One embodiment of the present invention provides the polymer film, which includes a polymer film and a silica layer coated on at least one surface of the polymer film, wherein the silica layer is derived from a silica precursor and can be decomposed in an environmentally friendly manner.

Description

Eco-friendly degradable polymer film and packaging material containing the same {ECO-FRIENDLY DEGRADABLE PLASTIC FILM AND PACKAGING MATERIAL COMPRISING THE SAME}

The present invention relates to an environmentally friendly degradable polymer film and a packaging material including the same, and more specifically, to a polymer film having excellent usability in real life and high degradability by modifying the surface of the environmentally friendly degradable polymer film to be hydrophobic, and including the same It's about the packaging material that does.

In general, since the polymer film used in real life is semi-permanent, the environmental pollution problem caused by the used waste film has emerged as a serious social problem. Therefore, it has a new function called 'environmentally degradable polymer film' that can replace the film that dramatically improves convenience when used, and can eliminate environmental problems by being disintegrated or decomposed after use and recycled to the natural cycle. There is a demand for the development of polymer films with

In particular, these days, it has been reported that there are many problems with the currently used film, such as reports that environmental hormones have been detected in various films through the mass media. Therefore, it can be said that it is urgent to develop a film having excellent degradability and improved physical properties.

On the other hand, the plastic waste accumulated in the ecosystem is continuously shredded by wind, waves, and photo-oxidation and converted into smaller and smaller pieces. Plastic debris that has been transformed in this way is called 'microplastic'. A polymer film made of poly(lactic acid), which is typically used as a biomass-based plastic (hereinafter, referred to as 'PLA film'), has a problem of generating microplastics because it is not completely biodegradable, There was also a problem with a very slow decomposition rate. The polymer film using a polymer compound derived from seafood proposed to solve these problems has the advantage of being environmentally friendly and degradable, but has a problem in that it is used for limited purposes in daily life due to the high hydrophilicity of the film surface.

An object of the present invention is to provide a polymer film that is hydrophobically modified and can be used for various purposes in real life and is environmentally friendly and degradable.

Another object of the present invention is to provide a polymer film that can be degraded in an environmentally friendly manner.

Another object of the present invention is to provide an environmentally friendly polymer film by modifying the surface of the film with an environmentally friendly material.

Another object of the present invention is to provide a method for manufacturing a polymer film that can be degraded in an environmentally friendly manner.

Another object of the present invention is to provide a packaging material comprising a polymer film that can be degraded in an environmentally friendly manner.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention not mentioned above can be understood by the following description and will be more clearly understood by the examples of the present invention. It will also be readily apparent that the objects and advantages of the present invention may be realized by means of the instrumentalities and combinations indicated in the claims.

One embodiment of the present invention for achieving the above object includes a polymer film and a silica layer coated on at least one surface of the polymer film, wherein the silica layer is derived from a silica precursor, an environmentally friendly decomposable polymer provide film. Specifically, the polymer film-forming composition for forming the polymer film may include 100 parts by weight of an alginate and 60 to 200 parts by weight of a plasticizer.

Specifically, the silica precursor may be any one selected from the group consisting of silane-based compounds, silicate-based compounds, and combinations thereof.

According to another embodiment of the present invention for achieving the above object, the silica layer may include a first layer and a second layer disposed on the first layer. The first layer and the second layer may each independently be derived from any one selected from the group consisting of the silane-based compound, the silicate-based compound, and combinations thereof.

Specifically, the silicate-based compound is selected from the group consisting of tetramethyl orthosilicate (TMOS), tetraethyl orthosilicate (TEOS), tetrapropyl orthosilicate (TPOS), and combinations thereof can be either

Specifically, the silane-based compound may be a compound represented by the following general formula (1).

[Formula 1]

In Formula 1, R ₁ , R ₂ and R ₃ may each independently be a chain or branched alkyl group having 1 to 5 carbon atoms, and R ₄ is substituted or unsubstituted with a halogen atom having 1 to 20 carbon atoms. cyclic alkyl groups; A cycloalkyl group unsubstituted or substituted with a halogen atom having 3 to 16 carbon atoms; A bicycloalkyl group unsubstituted or substituted with a halogen atom having 4 to 10 carbon atoms; and a bicycloalkenyl group unsubstituted or substituted with a halogen atom having 4 to 10 carbon atoms.

More specifically, the silane-based compound is methyltrimethoxysilane (MTMS), hexadecyltrimethoxysilane (HDTMS), n-octyltrimethoxysilane (OTMS), 5- It may be any one selected from the group consisting of (bicycloheptenyl)triethoxysilane (5-(bicycloheptenyl)triethoxysilane) and combinations thereof.

The composition for forming the silica layer may include 100 parts by volume of the first solvent and 4 to 16 parts by volume of the silica precursor.

According to another embodiment of the present invention for achieving the above object, it is possible to provide a polymer film further comprising a wax layer coated on one surface of the silica layer.

Another embodiment of the present invention for achieving the above object may provide a packaging material including the polymer film.

The solution to the above problems does not enumerate all the features of the present invention. Various features of the present invention and the advantages and effects thereof will be understood in more detail with reference to the following specific examples.

According to one embodiment of the present invention, it is possible to provide an eco-friendly degradable polymer film that has high biodegradability and is modified to be hydrophobic and can be used for various purposes in real life. In addition, by using an environmentally friendly material as a reforming method, it is possible to provide an environmentally friendly polymer film that prevents environmental pollution. This eco-friendly polymer film can be widely applied to applications such as flexible packaging materials.

In addition to the above effects, specific effects of the present invention will be described together while explaining specific details for carrying out the present invention.

1 is a schematic view of a polymer film that can be decomposed in an environmentally friendly manner according to an embodiment of the present invention.
Figure 2 is according to Comparative Example 1, Examples 1 and 9, and shows a photograph of a water droplet placed on the surface of an environmentally friendly degradable polymer film.
Figure 3 is according to Preparation Example 3 according to the coating time, showing the contact angle of water droplets on a polymer film that can be degraded in an environmentally friendly manner.
Figure 4 is according to Preparation Example 3 according to the coating time, showing the mass change rate of the polymer film capable of environmentally friendly decomposition.
5 is a contact angle of water droplets on environmentally friendly decomposable polymer films according to Examples 7 to 9, 1 and 10 (HD_2.7) and Examples 19 to 22 and 5 (MT_16) when the coating time is varied. was compared.

Hereinafter, each configuration of the present invention will be described in more detail so that those skilled in the art can easily practice it, but this is only one example, and the scope of the present invention is Not limited.

One embodiment of the present invention provides a polymer film that is environmentally friendly and degradable, including a polymer film and a silica layer coated on at least one surface of the polymer film, wherein the silica layer is derived from a silica precursor. According to one embodiment of the present invention, by imparting hydrophobicity to the surface of a polymer film (calcium alginate film), it is possible to provide an eco-friendly degradable polymer film that can be applied to various uses in daily life.

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

1. Eco-friendly degradable polymer film

The environmentally friendly degradable polymer film according to the present invention includes a polymer film.

The polymer film-forming composition for forming the polymer film may include a seafood-derived polymer compound derived from seafood. The seafood may be any one selected from the group consisting of brown algae, red algae, green algae, and combinations thereof, and may preferably be brown algae. The brown algae may be, for example, wakame, kelp, or kelp.

The seafood-derived polymer compound according to the present invention may be a polysaccharide extracted from seafood. Specifically, the seafood-derived polymer compound may be an alginate, and more specifically, the alginate may be sodium alginate or potassium alginate.

The weight average molecular weight of the alginate may be 10,000 to 100,000 g/mol, preferably 10,000 to 50,000 g/mol, and more preferably 10,000 to 30,000 g/mol. When the weight average molecular weight of the alginate is less than the above numerical range, the strength of the polymer film of the present invention may be lowered, and when it exceeds the above numerical range, the viscosity of the composition for forming a polymer film is excessively high, making it difficult to prepare a polymer film. The efficiency of the injection molding process for

The content of the alginate according to the present invention may be 27 to 43% by weight, preferably 35 to 43% by weight, more preferably 40 to 42% by weight based on the total weight of the composition for forming a polymer film. . When the content of the alginate is within the above numerical range, the degradability and physical properties of the polymer film of the present invention can be optimized.

The composition for forming a polymer film according to the present invention may include a plasticizer that lowers the viscosity of the composition and reduces deformation of the film due to external force. The plasticizer may include an alcohol compound. The alcohol compound may be, for example, any one selected from the group consisting of glycerin, xylitol, mannitol, sorbitol, and combinations thereof.

The composition for forming the polymer film may include 100 parts by weight of an alginate and 60 to 200 parts by weight of a plasticizer. The amount of the plasticizer may be preferably 60 to 100 parts by weight, more preferably 60 to 80 parts by weight based on 100 parts by weight of the alginate. High stiffness and tensile strength of the polymer film of the present invention can be implemented only when the content of the plasticizer is within the above numerical range.

The composition for forming a polymer film according to another embodiment of the present invention may further include 40 to 110 parts by weight of an oil-based additive based on 100 parts by weight of the alginate. The oil-based additive may be used to adjust the stiffness of the film.

The oil-based additive according to the present invention includes any one selected from the group consisting of oleic acid, linoleic acid, linolenic acid, stearic acid, palmitic acid, myristic acid, lauric acid, and combinations thereof can do. For example, the oil-based additive may be sunflower seed oil.

The content of the oil-based additive may be preferably 40 to 90 parts by weight, more preferably 40 to 80 parts by weight based on 100 parts by weight of the alginate. The high stiffness of the polymer film of the present invention can be implemented only when the content of the oil-based additive is within the above numerical range. In addition, as the content of the oil-based additive increases, bonding strength between the silica layer and the polymer film to be described later may increase.

The composition for forming a polymer film according to another embodiment of the present invention may further include 1 to 20 parts by weight of a filler based on 100 parts by weight of the alginate. The filler may be added to increase strength and rigidity of the polymer film of the present invention.

The filler according to the present invention may be any one selected from the group consisting of protein-based additives, polysaccharide-based additives, and combinations thereof, and may preferably be a mixture of protein-based additives and polysaccharide-based additives. In this way, when two types of fillers are used, the strength and rigidity of the film can be further increased.

According to one embodiment of the present invention using a protein-based additive and two types of polysaccharide-based additives, the weight ratio of the polysaccharide-based additive and the protein-based additive (polysaccharide-based additive: protein-based additive) is 1: It may be 1 to 1:9, preferably 1:2 to 1:7, and more preferably 1:2 to 1:3. When the weight ratio of the polysaccharide-based additive and the protein-based additive is within the above numerical range, high stiffness, tensile strength and elongation at break of the polymer film of the present invention can be realized.

The protein-based additive may be, for example, any one selected from the group consisting of whey protein, gelatin, soy protein, keratin, and combinations thereof. The molecular weight of the protein-based additive may be, for example, 15 to 75 kDa.

The polysaccharide-based additive may include any one selected from the group consisting of α-cellulose, β-cellulose, nanocellulose, starch, and combinations thereof. The molecular weight of the polysaccharide-based additive may be, for example, 15 to 75 kDa. The polysaccharide-based additive may be starch containing a large amount of starch. The starch may be, for example, common corn starch, potato starch, or cassava starch.

The content of the filler may be preferably 2 to 10 parts by weight, more preferably 2 to 5 parts by weight based on 100 parts by weight of the alginate. The strength and rigidity of the polymer film of the present invention can be improved only when the content of the filler is within the above numerical range.

The composition for forming a polymer film according to another embodiment of the present invention may further include 1 to 5 parts by weight of a water barrier additive based on 100 parts by weight of the alginate. The moisture barrier additive may be added as needed to impart moisture barrier properties. The content of the moisture barrier additive may be appropriately adjusted. The moisture blocking additive may be, for example, mica having a particle size of 1 to 10 μm (micrometer).

A composition for forming a polymer film according to another embodiment of the present invention contains 27 to 43% by weight of an alginate, 22 to 50% by weight of an alcohol compound, 19 to 30% by weight of an oil-based additive, 0.3 to 8% by weight of a protein-based additive, and 0.3 to 4% by weight of the polysaccharide-based additive may be included.

The environmentally friendly degradable polymer film according to the present invention may include a silica layer coated on at least one surface of the polymer film in order to hydrophobically modify the surface of the polymer film. The silica layer may be coated on one side or both sides of the polymer film.

The thickness of the polymer film may vary depending on the frame, but may be, for example, 1 mm to 5 mm.

The silica layer may have a thickness of 0.01 to 20 μm, specifically 0.06 to 5 μm, and more specifically 0.12 to 2.5 μm. The thickness of the silica layer may vary depending on the coating time, but it is preferable to satisfy the above thickness range in order to satisfy both the water absorption rate of the polymer film of the present invention and the optimal range of the contact angle of water droplets with respect to the polymer film of the present invention. can do.

The silica layer is derived from a silica precursor, and may include a silica precursor chemically bonded to calcium alginate. The silica precursor may be any one selected from the group consisting of silane-based compounds, silicate-based compounds, and combinations thereof.

According to another embodiment of the present invention, the silica layer may include a first layer and a second layer disposed on the first layer. Specifically, the first layer and the second layer may each independently be derived from any one selected from the group consisting of the silane-based compound, the silicate-based compound, and combinations thereof. The thickness of the first layer may be 0.01 to 10 μm, specifically 0.06 to 5 μm, and more specifically 0.12 to 2.5 μm. The second layer may have a thickness of 0.01 to 10 μm, specifically 0.06 to 5 μm, and more specifically 0.12 to 2.5 μm. When the thicknesses of the first layer and the second layer are within the above numerical range, both the water absorption rate of the polymer film of the present invention and the contact angle of water droplets on the polymer film of the present invention can be achieved in an optimal range.

The silicate-based compound is, for example, selected from the group consisting of tetramethyl orthosilicate (TMOS), tetraethyl orthosilicate (TEOS), tetrapropyl orthosilicate (TPOS), and combinations thereof can be either However, the technical idea of the present invention is not limited thereto, and any silicate-based compound that imparts hydrophobicity to the surface of an eco-friendly decomposable polymer film can be applied.

The silane-based compound may be a compound represented by the following general formula (1).

[Formula 1]

In Formula 1, R ₁ , R ₂ and R ₃ may each independently be a chain or branched alkyl group having 1 to 5 carbon atoms, specifically a chain or branched alkyl group having 1 to 4 carbon atoms, and more Specifically, it may be a chain or branched alkyl group having 1 to 3 carbon atoms.

R ₄ is an alkyl group unsubstituted or substituted with a halogen atom having 1 to 20 carbon atoms; A cycloalkyl group unsubstituted or substituted with a halogen atom having 3 to 16 carbon atoms; A bicycloalkyl group unsubstituted or substituted with a halogen atom having 4 to 10 carbon atoms; and a bicycloalkenyl group unsubstituted or substituted with a halogen atom having 4 to 10 carbon atoms. Specifically, the 'alkyl group substituted with a halogen atom having 1 to 20 carbon atoms' may be a substituent in which at least one hydrogen atom is substituted with a halogen atom in an unsubstituted alkyl group having 1 to 20 carbon atoms. The cycloalkyl group substituted with a halogen atom of 3 to 16 may be a substituent in which at least one hydrogen is substituted with a halogen atom in a cycloalkyl group unsubstituted with a halogen atom having 3 to 16 carbon atoms, and specifically, 'a cycloalkyl group having 4 to 16 carbon atoms is substituted with a halogen atom. The bicycloalkyl group substituted with 16 halogen atoms' may be a substituent in which at least one hydrogen atom is substituted with a halogen atom in a bicycloalkyl group unsubstituted with a halogen atom having 4 to 16 carbon atoms, and 'substituted with a halogen atom having 4 to 16 carbon atoms. The 'bicycloalkenyl group' may be a substituent in which at least one hydrogen atom is substituted with a halogen atom in a bicycloalkenyl group unsubstituted with a halogen atom having 4 to 16 carbon atoms, and more specifically, the halogen atom is fluorine (F) and It may be one or more atoms selected from chlorine (Cl).

The silane-based compound, for example, methyltrimethoxysilane (MTMS), hexadecyltrimethoxysilane (HDTMS), n-octyltriethoxysilane (OTMS), 5-( It may be any one selected from the group consisting of bicycloheptenyl)triethoxysilane (5-(bicycloheptenyl)triethoxysilane) and combinations thereof.

The composition for forming the silica layer may include 100 parts by volume of the first solvent mixed with the silica precursor and 1 to 36 parts by volume of the silica precursor. Specifically, the content of the silica precursor may be 2 to 16 parts by volume, more specifically 4 to 16 parts by volume based on 100 parts by volume of the first solvent. When the content of the silica precursor is within the above numerical range, the water absorption rate of the polymer film of the present invention can be lowered, and by implementing a high contact angle of water droplets with respect to the polymer film, it is possible to sufficiently impart hydrophobicity to the surface of the polymer film. there is.

The first solvent may be, for example, alcohol having 1 to 6 carbon atoms, and more specifically, ethanol.

According to another embodiment of the present invention, the composition for forming a silica layer may include an acid catalyst to increase the reaction rate, if necessary. The acid catalyst may be, for example, HCl(aq).

According to another embodiment of the present invention, the eco-friendly decomposable polymer film may further include a wax layer coated on one surface of the silica layer. The wax layer may be physically coated on the surface of the hydrophobic silica layer to further modify the surface of the polymer film of the present invention to be hydrophobic.

The wax layer may have a thickness of 1 to 100 μm, specifically 10 to 70 μm, and more specifically 20 to 50 μm. When the thickness of the wax layer is within the above numerical range, the water absorption rate of the polymer film of the present invention may be lowered, and a high contact angle of water droplets with respect to the polymer film may be realized, thereby imparting hydrophobicity to the surface of the polymer film.

The wax layer may be, for example, any one selected from the group consisting of carnauba wax, beeswax, and mixtures thereof. However, the technical idea of the present invention is not limited thereto, and any of various polyester-based wax compounds may be applied.

According to another embodiment of the present invention, the volume ratio (carnauba wax: beeswax) of the carnauba wax and the beeswax in the mixture of the carnauba wax and the beeswax is 1: 0.1 to 1: 10 can be

2. Manufacturing method of environmentally friendly degradable polymer film

Another embodiment of the present invention is (S1) an eco-friendly degradable polymer film comprising the step of immersing the polymer film in a composition for forming a silica layer containing a silica precursor at 30 to 70 ° C. for 0.5 to 6 hours A manufacturing method can be provided. Specifically, the step of immersing the polymer film in the composition for forming a silica layer may be performed at 40 to 60° C. for 0.5 to 2 hours. When the coating time of the silica layer is within the above numerical range, the water absorption rate of the polymer film of the present invention can be lowered, and by realizing a high contact angle of water droplets with respect to the polymer film, hydrophobicity can be imparted to the surface of the polymer film. .

Meanwhile, the immersion time may correspond to the coating time for coating the silica layer.

Hereinafter, the configuration of the present invention will be described with reference to FIG. 1 . The foregoing parts and repeated descriptions are briefly described or omitted.

1 is a schematic diagram of a polymer film that can be degraded in an environmentally friendly manner according to an embodiment of the present invention.

Referring to FIG. 1, a method for producing an eco-friendly decomposable polymer film according to an embodiment of the present invention includes forming a silica layer on one side of a cured calcium alginate film and applying a wax layer on one side of the silica layer. Formation may be included. The silica layer can be chemically bonded with calcium alginate to impart hydrophobicity to the surface of the polymer film of the present invention, and the wax layer is coated on the surface of the silica layer by a physical method to improve the hydrophobicity of the surface of the polymer film of the present invention. more can be given.

3. Packaging materials

Another embodiment of the present invention may provide a packaging material including the environmentally friendly degradable polymer film.

When the packaging material is a multi-layered laminated structure, the environmentally-friendly degradable polymer film according to an embodiment of the present invention may be applied to one layer or a plurality of layers without limitation.

A packaging material according to another embodiment of the present invention may be constructed by combining the polymer film of the present invention and a conventional petrochemical film.

A packaging material according to another embodiment of the present invention may be constructed by combining the polymer film of the present invention and a conventional eco-friendly film (eg, PLA film).

A packaging material according to another embodiment of the present invention may be constructed by combining all of the polymer film of the present invention, a petrochemical film, and a conventional eco-friendly film.

Hereinafter, an embodiment of the present invention will be described in detail so that those skilled in the art can easily practice it, but this is only one example, and the scope of the present invention is Not limited.

[Synthesis Example 1: Synthesis of sodium alginate]

Brown algae waste and hydrogen peroxide solution (20%) at 60 ° C were mixed in a weight ratio of 1: 8 (brown algae waste: hydrogen peroxide), and the brown algae waste was immersed in hydrogen peroxide for one day. Thereafter, the hydrogen peroxide solution in which the brown algae waste was immersed after one day was dried in an oven at 100° C. to obtain only solids. The dried solids and the Na ₂ CO ₃ solution (2%) were mixed in a weight ratio of 1:20 (dried solids: Na ₂ CO ₃ solution), and the dried solids were immersed in the Na ₂ CO ₃ solution for 5 minutes. Then, the mixed solution was mixed with a mixer for 150 seconds, and the mixed result was stirred at 450 RPM for 6 hours. Then, only the supernatant was separated by centrifugation and mixed with excess ethanol. In this process, it was confirmed that a precipitate was formed, and only the precipitate was separated and dried by centrifugation, and finally sodium alginate having a weight average molecular weight of 1,994,030 g/mol was synthesized.

[Preparation Example 1-1: Preparation of polymer film (calcium alginate film)]

After mixing water (600mL) with sodium alginate (16.5g), glycerol (30g), sunflower seed oil (15g) and keratin (0.33g) according to Synthesis Example 1 in a mixer, it was applied to a petri dish. . Then, it was sufficiently immersed in a 2% (w/v) CaCl ₂ solution for 30 minutes to prepare a polymer film (calcium alginate film) having a thickness of 2 mm.

[Preparation Example 1-2: Preparation of polymer film (calcium alginate film)]

A polymer film was prepared in the same manner as in Preparation Example 1-1, but the content of sunflower seed oil was changed from 15 g to 30 g.

[Preparation Example 2-1: Preparation of Composition for Forming a Silica Layer Containing HDTMS]

A first solution was prepared by mixing 0.137 mL of hexadecyltrimethoxysilane (hereinafter referred to as 'HDTMS') with ethanol (5 mL) being heated to 60 °C. A composition for forming a silica layer was prepared by mixing the first solution with about 1.26 mL of 0.34% (w/v) HCl (aq). The content of the hexadecyltrimethoxysilane was adjusted to 2.74 parts by volume based on 100 parts by volume of the ethanol.

[Preparation Example 2-2: Preparation of a composition for forming a silica layer containing OTMS]

A composition for forming a silica layer was prepared in the same manner as in Preparation Example 2-1, but instead of 2.74 parts by volume of hexadecyltrimethoxysilane (HDTMS), 4.0 parts by volume of n-octyltriethoxysilane (OTMS) Volume parts were used.

[Preparation Example 2-3: Preparation of a composition for forming a silica layer containing OTMS]

A composition for forming a silica layer was prepared in the same manner as in Preparation Example 2-2, but the content of n-octyltriethoxysilane (hereinafter referred to as 'OTMS') was 4 parts by volume and 3 parts by volume. changed to

[Preparation Example 2-4: Preparation of a composition for forming a silica layer containing 5-(bicycloheptenyl)triethoxysilane]

A composition for forming a silica layer was prepared in the same manner as in Preparation Example 2-2, but the same amount of 5-(bicycloheptenyl)triethoxysilane instead of the n-octyltriethoxysilane (OTMS) was used.

[Preparation Example 2-5: Preparation of a composition for forming a silica layer containing MTMS]

A composition for forming a silica layer was prepared in the same manner as in Preparation Example 2-2, but instead of the n-octyltriethoxysilane (OTMS), the same amount of methyltrimethoxysilane (hereinafter referred to as 'MTMS') was used. referred to as) was used.

[Preparation Example 3: Preparation of composition for forming wax layer]

After mixing carnauba wax and beeswax in 50 mL of ethanol at a concentration of 10 mg/mL, respectively, the mixture was heated at 60° C. until the waxes completely melted. A mixture of ethanol in which the carnauba wax was dissolved and ethanol in which the beeswax was dissolved in a volume ratio of 1:1 was mixed with ultrasonic waves of 40 kHz and 425 W for 2 hours.

[Production Example 1: Production of environmentally friendly degradable polymer film]

Eco-friendly decomposable polymer films were prepared according to the following Comparative Examples and Examples.

<Comparative Example 1: Polymer film not hydrophobically modified>

As Comparative Example 1, the same polymer film as Preparation Preparation Example 1-1 was prepared.

<Example 1: Polymer film including a silica layer derived from HDTMS>

immersing the polymer film according to Preparation Example 1-1 in the composition for forming a silica layer according to Preparation Preparation Example 2-1 at 60° C. for 4 hours, and taking out the immersed product and wiping the surface of the film with ethanol Through this, an eco-friendly decomposable polymer film was prepared.

<Example 2: Polymer film including silica layer derived from OTMS>

An eco-friendly decomposable polymer film was prepared in the same manner as in Example 1, but the composition for forming a silica layer according to Preparation Example 2-2 was used instead of the composition for forming a silica layer according to Preparation Example 2-1. did

<Example 3: Unlike Example 2, a polymer film having a different OTMS content>

An eco-friendly decomposable polymer film was prepared in the same manner as in Example 2, but the composition for forming a silica layer according to Preparation Example 2-3 was used instead of the composition for forming a silica layer according to Preparation Example 2-2. And the immersion temperature of 60 ℃ was changed to 40 ℃.

<Example 4: Polymer film containing a silica layer derived from 5-(bicycloheptenyl)triethoxysilane>

An eco-friendly decomposable polymer film was prepared in the same manner as in Example 2, but the composition for forming a silica layer according to Preparation Example 2-4 was used instead of the composition for forming a silica layer according to Preparation Example 2-2. did

<Example 5: Polymer film including a silica layer derived from MTMS>

An eco-friendly decomposable polymer film was prepared in the same manner as in Example 2, but the composition for forming a silica layer according to Preparation Example 2-5 was used instead of the composition for forming a silica layer according to Preparation Example 2-2. and the immersion time was changed from 4 hours to 6 hours.

<Example 6: Unlike Example 5, when the polymer film according to Preparation Preparation Example 1-2 was used>

An eco-friendly decomposable polymer film was prepared in the same manner as in Example 5, but the polymer film according to Preparation Example 1-2 was used instead of the polymer film according to Preparation Preparation Example 1-1.

[Experimental Example 1: Contact angle and mass change rate analysis]

1) contact angle

In order to analyze the wettability of the surface of the environmentally friendly degradable polymer film, the contact angle was measured by the following method. After dropping water droplets (30 μL) with a syringe on one side of the polymer film (thickness: 0.2 mm) according to Preparation Example 1 at 25 ° C., the polymer The contact angle of water droplets on the surface of the film was measured. The higher the contact angle, the stronger the degree of hydrophobic modification of the surface of the polymer film.

2) Mass change rate of polymer film after being immersed in water for 1 hour

The mass change rate after immersing the polymer film (thickness: 0.2 mm) according to Preparation Example 1 in water at 25 ° C. for 1 hour was calculated according to Equation 1 below and is shown in Table 1 below.

[Equation 1]

Mass change rate (%) of polymer film = (m _f -m _i )/m _i x 100

In Equation 1, m _{f =} the mass of the polymer film after being immersed in water for 1 hour, and m _i = the initial mass of the polymer film. As the mass change rate is lower, it can be inferred that the surface of the polymer film is more hydrophobically modified, and the mass change rate can be defined as equivalent to the water absorption rate.

However, in Table 1 below, the concentration of the silica precursor was set based on 100 parts by volume of ethanol (EtOH).

sample silica precursor
immersion
Temperature (℃) immersion
hour Contact angle (°) Mass change rate (%) note Kinds density
(by volume) Comparative Example 1 - - - - 45.6 305 hydrophobicity
Modified X Example 1 HDTMS 2.74 60 4 93.4 30.90 Manufacturing preparation example 1-1 Example 2 OTMS 4 60 4 89.6 35.75 Manufacturing preparation example 1-1 Example 3 OTMS 3 40 4 94.5 25.19 Manufacturing preparation example 1-1 Example 4 5-(bicycloheptenyl)triethoxysilane 4 60 4 85.1 61.89 Manufacturing preparation example 1-1 Example 5 MTMS 4 60 6 87.9 47.15 Manufacturing preparation example 1-1 Example 6 MTMS 4 60 6 94.9 24.64 Manufacturing preparation example 1-2

Referring to Table 1, it can be seen that the mass change rate of all examples is significantly lowered compared to Comparative Example 1 in which hydrophobicity is not imparted to the silica layer. Through this, it can be confirmed that hydrophobicity is sufficiently imparted by coating the silica layer on the surface of the polymer film. In particular, it can be inferred that Example 1 using HDTMS and Example 5 using MTMS as a silica precursor had significantly lower mass change rates than other Examples, and that hydrophobicity was sufficiently imparted.

In addition, comparing Examples 5 and 6, it is inferred that the adhesive force between the silica layer and the calcium alginate film is further increased when the content of oil is increased in the composition for forming a polymer film forming a calcium alginate film (polymer film). can do.

[Preparation Example 2: Preparation of polymer film according to immersion time]

An eco-friendly degradable polymer film was prepared in the same manner as in Preparation Example 1, but the immersion time (coating time) was varied under the conditions described in Table 2 below. However, in Table 2 below, the concentration of the silica precursor was set based on 100 parts by volume of ethanol (EtOH).

sample
(HD_2.7) HDTMS volume (mL) EtOH
volume
(mL) Concentration of Silica Precursor
(by volume) catalyst
reagent
catalyst
reagent
Volume (mL) water volume (mL) immersion
Temperature
(℃) immersion
time
(hour) Example 7 0.137 5 2.74 HCl 0.0115 1.25 60 0.5 Example 8 1.0 Example 9 2.0 Example 1 4.0 Example 10 6.0

[Experimental Example 2: Optimization experiment in case of using HDTMS as a silica precursor]

In the same manner as in Experimental Example 1, the contact angle of water droplets on the polymer film according to Preparation Example 2 and the mass change rate of the polymer film were evaluated and shown in Table 3 below. The foregoing parts and repeated descriptions are omitted.

Sample (HD_2.7) Immersion time (hour) Contact angle (°) Mass change rate (%) Example 7 0.5 103.2 31.84 Example 8 One 98.6 32.32 Example 9 2 96.2 30.17 Example 1 4 93.4 30.90 Example 10 6 108 35.54

Referring to Example 1 and Examples 7 to 10 in Table 3, a high contact angle and a low mass change rate (moisture absorption rate) were shown in all immersion time periods, but when the silica layer was coated for more than 6 hours, other silica precursors Similar to , it can be confirmed that the mass change rate tends to increase. That is, when HDTMS is used as a silica precursor, it can be inferred that the optimal coating time (immersion time) of the silica layer corresponds to 0.5 to 6 hours.

Figure 2 shows a photograph of water droplets placed on the surface of the polymer film according to Comparative Example 1 and Examples 1 and 9.

Referring to FIG. 2, it can be visually inferred that Comparative Example 1 has the lowest contact angle of water droplets on the polymer film compared to Examples 1 and 9 because the surface of the polymer film is not hydrophobically modified.

[Preparation Example 3: Preparation of polymer film according to concentration of silica precursor and immersion time]

A polymer film was prepared in the same manner as in Example 5, but the immersion time (coating time) and the concentration of the silica precursor were varied under the conditions shown in Table 4 below. However, the concentration of the silica precursor was set based on 100 parts by volume of ethanol (EtOH).

sample MTMS volume (mL) EtOH
volume
(mL) of silica precursor
density
(by volume) catalyst
reagent
catalyst
reagent
Volume (mL) water
Volume (mL) immersion
Temperature
(℃) immersion
hour MT_4 Example 11 0.2 5 4 HCl 0.0115 1.25 60 0.5 Example 12 1.0 Example 13 2.0 Example 14 4.0 MT_8 Example 15 0.37 4.63 8 0.5 Example 16 1.0 Example 17 2.0 Example 18 4.0 MT_16 Example 19 0.69 4.31 16 0.5 Example 20 1.0 Example 21 2.0 Example 22 4.0 MT_35 Example 23 1.3 3.7 35 0.5 Example 24 1.0 Example 25 2.0 Example 26 4.0

[Experimental Example 3: Optimization experiment in the case of using MTMS as a silica precursor]

In the same manner as in Experimental Example 1, the contact angle of water droplets on the polymer film according to Preparation Example 3 and the mass change rate of the polymer film were evaluated. The foregoing parts and repeated descriptions are omitted.

Figure 3 shows the contact angle of water droplets on the polymer film according to Preparation Example 3 according to the coating time.

Referring to FIG. 3, it can be seen that the contact angle tends to increase as the concentration of the silica precursor, MTMS, increases. That is, when the content of MTMS was 4 parts by volume and 8 parts by volume (low concentration) based on 100 parts by volume of ethanol, the contact angle showed a tendency to increase with coating time, and at 16 parts by volume and 35 parts by volume (high concentration), 2 parts by volume The contact angle tended to decrease with time.

Figure 4 shows the mass change rate of the polymer film according to Preparation Example 3 according to the coating time.

Referring to FIG. 4, it can be seen that the concentration of the silica precursor and the coating time independently affect the water absorption rate (mass change rate) in the polymer film according to Preparation Example 3.

3 and 4 are comprehensively compared, the optimal coating time that satisfies both the water absorption rate (mass change rate) and the appropriate range of the contact angle is 0.5 to 2 hours, and the optimal concentration of the silica precursor is 4 based on 100 parts by volume of ethanol. to 16 parts by volume.

In addition, considering Experimental Examples 2 and 3 comprehensively, it can be inferred that HDTMS having a relatively high carbon number is preferably 4 hours or more for coating the silica layer compared to MTMS. This is presumed to be due to the relatively slow reaction rate of HDTMS compared to MTMS.

[Experimental Example 5: Comparison of contact angles of HD_2.7 and MT_16 polymer films]

Figure 5 compares the contact angle of water droplets on the polymer films according to Examples 7 to 9, 1 and 10 (HD_2.7) and Examples 19 to 22 and 5 (MT_16) when the coating time is different.

Referring to FIG. 5, in the case of the polymer films (HD_2.7) according to Examples 7 to 9, 1 and 10, it can be seen that the contact angle of water droplets on the polymer film increases as the coating time increases. In addition, in the case of the polymer films (MT_16) according to Examples 19 to 22 and 5, the contact angle of water droplets on the polymer film tended to increase until the coating time was 2 hours before, but the contact angle changed after 2 hours had elapsed. It can be seen that there is almost no

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concept of the present invention defined in the following claims are also present. It falls within the scope of the right of invention.

Claims (11)

polymer film; and
A silica layer coated on at least one surface of the polymer film; and
Further comprising a wax layer physically coated on one side of the silica layer,
In an eco-friendly degradable polymer film,
The silica layer is derived from a silica precursor chemically bonded with alginate,
The silica precursor,
Any one selected from the group consisting of silane-based compounds, silicate-based compounds, and combinations thereof;
The silica layer includes a first layer having a thickness of 0.01 to 10 μm and a second layer disposed on the first layer and having a thickness of 0.01 to 10 μm independent of the first layer,
The composition for forming a polymer film for forming the polymer film,
100 parts by weight of an alginate derived from seafood; 60 to 200 parts by weight of a plasticizer;
40 to 110 parts by weight of an oil-based additive; and
contains a filler;
The filler includes a protein-based additive and a polysaccharide-based additive, and the weight ratio of the polysaccharide-based additive and the protein-based additive is 1: 1 to 1: 9,
Polymer film that can be degraded in an eco-friendly way.
delete delete delete delete According to claim 1,
The silicate-based compound,
Any one selected from the group consisting of tetramethyl orthosilicate (TMOS), tetraethyl orthosilicate (TEOS), tetrapropyl orthosilicate (TPOS), and combinations thereof,
Polymer film that can be degraded in an eco-friendly way.
According to claim 1,
The silane-based compound,
A compound represented by the following general formula 1
Polymer film that can be degraded in an eco-friendly way.
[Formula 1]

(In Formula 1 above,
R ₁ , R ₂ and R ₃ are each independently a chain or branched alkyl group having 1 to 5 carbon atoms;
R ₄ is an alkyl group unsubstituted or substituted with a halogen atom having 1 to 20 carbon atoms; A cycloalkyl group unsubstituted or substituted with a halogen atom having 3 to 16 carbon atoms; A bicycloalkyl group unsubstituted or substituted with a halogen atom having 4 to 10 carbon atoms; And a bicycloalkenyl group unsubstituted or substituted with a halogen atom having 4 to 10 carbon atoms; any one selected from the group consisting of.)
According to claim 7,
The silane-based compound,
Methyltrimethoxysilane (MTMS), hexadecyltrimethoxysilane (HDTMS), n-octyltriethoxysilane (OTMS), 5-(bicycloheptenyl)triethoxysilane (5- (bicycloheptenyl) triethoxysilane) and any one selected from the group consisting of combinations thereof,
Polymer film that can be degraded in an eco-friendly way.
According to claim 1,
The silica layer forming composition for forming the silica layer,
100 parts by volume of the first solvent and
Comprising 4 to 16 parts by volume of the silica precursor
Polymer film that can be degraded in an eco-friendly way.
According to claim 1,
a wax layer coated on one surface of the silica layer; further comprising
Polymer film that can be degraded in an eco-friendly way.
A packaging material comprising the eco-friendly decomposable polymer film according to any one of claims 1 and 6 to 10.

Images