KR20220005425A - Moisture barrier biodegradable film, packaging sheet and sticker comprising the film - Google Patents

Abstract

Provided are a moisture barrier biodegradable film which comprises: a biodegradable film composed only of a polylactic acid resin film, a polybutylene adipate-co-terephthalate resin film, a polycaprolactone resin film, or a polybutylene succinate resin film; a water-soluble acrylic coating layer positioned on the biodegradable film; and a protective layer positioned on the water-soluble acrylic coating layer, wherein the water-soluble acrylic coating layer comprises a water-soluble polyacrylic resin, the protective layer comprises a urethane resin, and the thickness of the protective layer is thinner than the thickness of the water-soluble acrylic coating layer, and a wrapping paper and a sticker comprising the moisture barrier biodegradable film.

Description

Moisture barrier biodegradable film, wrapping paper and sticker comprising the film {MOISTURE BARRIER BIODEGRADABLE FILM, PACKAGING SHEET AND STICKER COMPRISING THE FILM}

The present disclosure relates to a moisture barrier biodegradable film, a wrapping paper and a sticker comprising the film.

The packaging of fruits such as bananas and fast food products (gimbap, ginseng gimbap, sandwiches, hamburgers, etc.) currently sold in bakeries and convenience stores is made of polypropylene, a general-purpose plastic derived from petroleum. Polypropylene has excellent moisture barrier properties, so it prevents moisture escape from bakery products, etc., so it is effective in the growth of mold and bacteria.

Recently, the carbon tax and carbon credit trading system are being actively reviewed in order to prepare resources for green growth investment and reduce global greenhouse gas emissions. Polypropylene also takes more than 100 years to decompose after being discarded, and as it decomposes, it turns into microplastics, accelerating the pollution of the ecosystem.

Due to this movement, interest in biodegradable films that are decomposed in nature and whose raw materials are eco-friendly is increasing. In particular, studies and applications of polylactic acid, which are highly biodegradable aliphatic polyesters, are being conducted.

However, polylactic acid, which is used the most as a biodegradable film, is very vulnerable to moisture, so it is not widely used as a food packaging material that plays a role in food protection and distribution safety. In fact, the water permeability of polylactic acid is about 50 times that of polypropylene.

Due to these differences in physical properties, polypropylene is still widely used in packaging of fruits, bakery products, sandwiches, gimbap, hamburgers, etc. despite environmental problems.

Recently, due to problems with polypropylene, a coated film on which an oxide such as silica or alumina, which has better barrier performance than polypropylene, is deposited, or a film coated with or laminated with PVDC, etc., is used instead of polypropylene. Such a film They also contain metals and chlorine, so they do not help at all to solve environmental problems.

One embodiment uses a biodegradable film as a wrapping paper to avoid environmental contamination issues such as polypropylene, and at the same time, a moisture barrier biodegradable film that can solve the disadvantage of a biodegradable film, such as high moisture permeability, which lowers the barrier performance against moisture. is to provide

Another embodiment is to provide a wrapping paper comprising the moisture barrier biodegradable film.

Another embodiment is to provide a sticker including the moisture barrier biodegradable film.

One embodiment provides a water barrier biodegradable film comprising a biodegradable film and a water-soluble acrylic coating layer positioned on the biodegradable film, wherein the water-soluble acrylic coating layer includes a water-soluble polyacrylic resin.

The biodegradable film may be a polylactic acid resin film, a polybutylene adipate-co-terephthalate resin film, a polycaprolactone resin film, or a polybutylene succinate resin film.

The water-soluble acrylic coating layer may further include an antifoaming agent, a pH adjusting agent, or a combination thereof.

The moisture barrier biodegradable film may further include a protective layer on the water-soluble acrylic coating layer.

The protective layer may include a water-soluble urethane resin.

The protective layer may further include a slip agent.

The protective layer may further include an antifoaming agent, a pH adjusting agent, or a combination thereof.

The moisture barrier biodegradable film may further include a printed layer between the water-soluble acrylic coating layer and the protective layer.

The water barrier biodegradable film including the biodegradable film and the water-soluble acrylic coating layer may have a water permeability of 50 g/m ² *day to 110 g/m ² *day.

The biodegradable film, the water-soluble biodegradable film including the water-soluble acrylic coating layer and the protective layer may have a water permeability of 10 g/m ² *day to 70 g/m ² *day.

The moisture barrier biodegradable film may be a transparent moisture barrier biodegradable film.

Another embodiment comprises the steps of coating a water-soluble polyacrylic resin coating solution on a biodegradable film; and drying after the coating to obtain a water-soluble acrylic coating layer on the biodegradable film.

The water-soluble polyacrylic resin coating solution may have a pH of 8.0 to 9.5.

The water-soluble polyacrylic resin coating solution may include 40 to 50 wt% of the water-soluble polyacrylic resin based on the total amount of the coating solution.

In the coating step, the coating amount of the water-soluble polyacrylic resin coating solution may be 1.0 g/m ³ to 4.0 g/m ³ .

The drying may be performed at a speed of 40 rpm to 100 rpm under a temperature condition of 50° C. to 80° C. in a drying hood having a length of 3 m or more.

The drying hood may include a preheating unit, a first drying unit, and a second drying unit, and a temperature of each of the preheating unit and the second drying unit may be lower than a temperature of the first drying unit.

The water barrier biodegradable film manufacturing method may be a transparent water barrier biodegradable film manufacturing method.

The biodegradable film may be a polylactic acid resin film, a polybutylene adipate-co-terephthalate resin film, a polycaprolactone resin film, or a polybutylene succinate resin film.

The water-soluble polyacrylic coating solution may further include an antifoaming agent, a pH adjusting agent, or a combination thereof.

The moisture barrier biodegradable film manufacturing method comprises the steps of coating a water-soluble urethane resin coating solution on the water-soluble coating layer; And after coating the water-soluble urethane resin coating solution may further include the step of drying it.

The water-soluble urethane resin coating solution may include 20 wt% to 30 wt% of the water-soluble urethane resin based on the total amount of the coating solution.

In the step of coating the water-soluble urethane resin coating solution, the coating amount of the water-soluble urethane resin coating solution may be 0.5 g/m ³ to 3.0 g/m ³ .

The water-soluble urethane resin coating solution may further include a slip agent, an antifoaming agent, a pH adjusting agent, or a combination thereof.

Another embodiment provides a moisture barrier biodegradable film prepared by the above manufacturing method.

Another embodiment provides a wrapping paper comprising the moisture barrier biodegradable film.

The wrapping paper may be a wrapping paper for food.

The food may include fruits, cakes, sandwiches, hamburgers, gimbap or bakery products.

Another embodiment provides a sticker including the moisture barrier biodegradable film.

The specific details of other aspects of the invention are included in the detailed description below.

The moisture barrier biodegradable film according to an embodiment solves a problem in which the barrier performance against moisture, which is a problem of the conventional biodegradable film, is greatly reduced, so that the biodegradable film can be used in fruits, cakes, sandwiches, bakeries, hamburgers, gimbap, etc. By allowing it to be used as a wrapping paper, it is possible to completely solve the problem of environmental pollution of conventional wrapping paper such as polypropylene. This is because, unlike conventional plastics such as polypropylene, biodegradable films can be landfilled and degraded in nature. In addition, since existing plastic products are not used, the microplastic problem can also be solved.

Furthermore, since a separate barrier material is not laminated on the film, it is very eco-friendly in that the amount of waste and carbon emission generated during film production can be greatly reduced.

In addition, the packaging paper can be manufactured by varying the moisture barrier properties of the film depending on the product to be packaged, so that it is possible to provide a packaging paper optimized for the product to be packaged. For example, fruits and vegetables require moisture release to some extent, so the film is manufactured to have low moisture barrier properties of the wrapping paper, and bakery products do not require moisture release, so the moisture barrier properties of the wrapping paper packaging it It is necessary to prepare a film so that it is high. According to one embodiment, the moisture barrier property can be varied depending on whether or not a protective layer is added, and the moisture barrier property can be improved by varying the thickness of each layer constituting the film. It can be different, so it is possible to provide packaging optimized for different products.

1 and 2 are each independently a cross-sectional view showing a moisture barrier biodegradable film according to an embodiment.
3 is a diagram schematically illustrating a device used in a water barrier biodegradable film manufacturing process according to an embodiment.

The present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosed subject matter may be thorough and complete, and that the spirit of the present invention may be sufficiently conveyed to those skilled in the art.

The conventional moisture barrier film was prepared by depositing alumina or silica or coating the film with a barrier material such as PVDC. This deposition and coating method is difficult to apply to a biodegradable film that is weak to heat because the operation is made under high temperature conditions. (The thermal deformation temperature of the biodegradable film is about 80 ° C (a temperature higher than 80 ° C), whereas the thermal evaporation temperature in the production of a conventional moisture barrier film is about 300 ° C, and the drying temperature of the PVDC coating film is about 120 ° C.) In addition, the PVDC coating film has problems such as the release of environmental hormones during incineration. Recently, awareness of the environment has increased and environmental issues are increasing, such as legislation to ban the use of disposable containers due to problems such as the release of environmental hormones. Attempts are continuing. However, the biodegradable film itself is not suitable for use as an eco-friendly material, but has low barrier performance against moisture, so it is not suitable for use as a food packaging material. (The biodegradable film itself has very low moisture barrier properties, so if it is used alone as a packaging material for vegetables or fruits, the moisture loss of vegetables or fruits is excessive, which actually lowers the storage stability of the product.)

On the other hand, in the case of packaging food, depending on the food, it is necessary to use a packaging material with high moisture barrier properties, and sometimes it is necessary to use a packaging material with low moisture barrier property. For example, in the case of vegetables and fruits, since the vegetables or fruits breathe by themselves, some amount of moisture is discharged out of the packaging material through the packaging material, which can improve the storage stability by increasing the freshness of the packaged vegetables or fruits. On the other hand, in the case of bakery products, it is preferable to use a packaging material with high moisture barrier properties to prevent moisture from easily escaping because the bakery products harden when moisture escapes.

Because of these points, the development of food packaging paper using eco-friendly materials has not yet been fully developed, and economic feasibility is greatly reduced when a film is produced by applying a different process for each type of food to be packaged. The demand for an optimized moisture barrier eco-friendly (biodegradable) film is still continuing.

After a long study, the present inventors were able to solve all of the above-mentioned problems by coating a water-soluble acrylic coating layer containing a water-soluble polyacrylic resin on a biodegradable film.

Specifically, the acrylic coating layer coated on the biodegradable film is a water-soluble layer. Due to this, since the film according to an embodiment easily dissolves in water even when discarded, it may not cause an environmental pollution problem.

In addition, the water-soluble acrylic coating layer does not contain polyvinyl alcohol, inorganic substances, oxides, etc. in addition to the water-soluble polyacrylic resin. In the past, there have been attempts to mix and use polyvinyl alcohol, inorganic substances, oxides, etc. together to prevent deterioration of the functionality of the film, but this is not preferable because it may cause environmental pollution problems. In one embodiment, by greatly simplifying the composition of the water-soluble acrylic coating layer, environmental pollution problems that may be caused by additional additives are fundamentally blocked.

Furthermore, the biodegradable film may be a polylactic acid resin film, a polybutylene adipate-co-terephthalate resin film, a polycaprolactone resin film, or a polybutylene succinate resin film. That is, the biodegradable film refers to, for example, the polylactic acid resin film itself, and does not include additional additives (such as oxides) or polymers in addition to the polylactic acid resin film.

On the other hand, since the water-soluble acrylic coating layer serves to fill the pores in the biodegradable film, it is possible to significantly lower the moisture permeability, thereby greatly improving the moisture barrier properties of the film according to an embodiment.

That is, one embodiment greatly simplifies the composition of the biodegradable film and the coating layer coated on the biodegradable film, and limits the coating layer to a water-soluble component, thereby providing an environmentally friendly and excellent moisture barrier film.

For example, the biodegradable film may be a resin film conforming to EL724 certification, which is an environment-friendly certification standard by the Ministry of Environment, for example, a polylactic acid resin film having a dissolution test standard for food. However, in consideration of biodegradability and compatibility with the water-soluble acrylic coating layer, polyethylene terephthalate resin film, polybutylene terephthalate resin film, polyethylene naphthalate resin film, etc. It is not preferable to use the biodegradable film according to one embodiment. it may not be

The water-soluble acrylic coating layer may further include an antifoaming agent, a pH adjusting agent, or a combination thereof, if necessary. However, the antifoaming agent, the pH adjusting agent, etc. may be excluded from the metal oxide associated with environmental pollution.

On the other hand, even if the water-soluble acrylic coating layer is coated on the biodegradable film, the possibility that the water-soluble acrylic coating layer is broken or contaminated during the printing operation or distribution process of the wrapping paper and loss of the moisture barrier function cannot be excluded.

The water barrier biodegradable film composed of the biodegradable film and the water-soluble acrylic coating layer coated on the biodegradable film may have a water permeability ^{of 50 g/m 2} *day to 110 g/m ^{2 *day.} That is, the water permeability of the biodegradable film was greatly reduced due to the addition of the water-soluble acrylic coating layer, and the biodegradability of the biodegradable film was not affected by configuring the acrylic coating layer with a water-soluble material.

In one embodiment, it is possible to provide a moisture barrier biodegradable film further comprising a protective layer on the water-soluble acrylic coating layer to compensate for this problem.

The protective layer may include a water-soluble urethane resin having strong ductility and excellent durability and chemical resistance.

When the protective layer including the water-soluble urethane resin is added on the water-soluble acrylic coating layer, the protective layer not only serves to protect the water-soluble acrylic coating layer, but also covers the voids in the water-soluble acrylic coating layer. , it is possible to further improve the water barrier performance by lowering the water permeability resin of the entire film.

The protective layer may further include a slip agent. In this case, it is possible to more effectively prevent tearing of the coating layer constituting the moisture barrier biodegradable film or the printing layer to be described later, and slip property is provided to enable smooth operation in food packaging facilities.

The protective layer may further include an antifoaming agent, a pH adjusting agent, or a combination thereof, if necessary. However, the antifoaming agent, the pH adjusting agent, etc. may be excluded from the metal oxide associated with environmental pollution.

The moisture barrier biodegradable film may further include a printed layer between the water-soluble acrylic coating layer and the protective layer. The ink used for the printing layer may be an alcohol ink, for example, an ethanol ink. In the past, ethyl acetate, methyl ethyl ketone, toluene, etc. were used as solvents when using the ink used for the printing layer. These solvents are all toxic substances with very strong organic volatility, which can cause air pollution. Above all, polylactic acid Because it dissolves even biodegradable films such as resin film, polybutylene adipate-co-terephthalate resin film, polycaprolactone resin film, and polybutylene succinate resin film, it is applied to the moisture barrier biodegradable film according to one embodiment. may not be suitable. However, the ethanol ink does not cause the above-mentioned air pollution and does not melt the biodegradable film, so it is environmentally friendly and may be suitable for application to the moisture barrier biodegradable film according to an embodiment.

The water barrier biodegradable film composed of the biodegradable film, the water-soluble acrylic coating layer positioned on the biodegradable film, and the protective layer positioned on the water-soluble acrylic coating layer (or further comprising a printed layer) is 10 g/m ² *day to It may have a water permeability of 70 g/m ^{2 *day.} Due to the protective layer, the moisture permeability of the moisture barrier biodegradable film can be further lowered, and since the protective layer can also be made of a water-soluble urethane resin, it may not affect the biodegradability of the biodegradable film.

For example, the moisture barrier biodegradable film may be a transparent moisture barrier biodegradable film.

According to another embodiment, coating the water-soluble polyacrylic resin coating solution on the biodegradable film; and drying after the coating to obtain a water-soluble acrylic coating layer on the biodegradable film.

In the case of manufacturing a film used for conventional food packaging, the lamination process (barrier film lamination process for imparting barrier performance) and the perforation process (a separate drilling process for discharging ethylene gas generated by product respiration when packaging vegetables or fruits) ) was essential, and according to one embodiment, the laminating process, which was a conventional essential process, is unnecessary, and the drilling process is also very simply performed in an in-line method, or in some cases, the drilling process itself is not required. , a reduction in carbon dioxide due to the reduction of the manufacturing process can be expected. In addition, since the laminating process is unnecessary, it is possible to reduce the weight of the finally manufactured wrapping paper, thereby reducing the amount of waste, which is eco-friendly.

The water-soluble polyacrylic resin coating solution is basic, for example, having a pH of 8.0 to 9.5 has water-soluble properties, and may be easily decomposed upon disposal after use.

The water-soluble polyacrylic resin coating solution may include 40 to 50 wt% of the water-soluble polyacrylic resin based on the total amount of the coating solution. That is, the water-soluble polyacrylic resin coating solution may be composed of 40 wt% to 50 wt% of the water-soluble polyacrylic resin and 50 wt% to 60 wt% of a solvent such as water. When using the water-soluble polyacrylic resin coating solution containing the water-soluble polyacrylic resin in the above range, it is possible to simultaneously achieve eco-friendly characteristics and high barrier performance against moisture.

In the coating step, the coating amount of the water-soluble polyacrylic resin coating solution may be 1.0 g/m ³ to 4.0 g/m ³ . When the coating amount of the coating solution is within the above range, the coating amount is appropriate, so that the coating is performed smoothly, and the barrier performance against moisture can be excellent.

The coating may be coated using a method such as a gravure coater, a bar coater, a flexo coater, a spray coater, or a blade coater. Among them, in the coating conditions of the gravure method, the copper plate of Herio and laser method is used, but the water-soluble polyacrylic resin coating solution applied by applying the low depth and laser plate must be well spread.

The biodegradable film is weak to heat and can be decomposed by moisture, so drying conditions are important, and since the polyacrylic resin coating solution is water-soluble, when it is not dried sufficiently, transparency is lowered and the applied coating solution may be peeled off, so a drying hood having a length of 3 m or more It may be preferable to carry out the drying at a rate of 60 rpm to 120 rpm under a temperature condition of 60 ° C to 80 ° C.

For example, as the coating amount of the water-soluble polyacrylic resin coating solution is small ( ^{closer to 1.0 g/m 3} ), the drying speed may be faster (up to 120 rpm), and the more the coating amount of the water-soluble polyacrylic resin coating solution is (4.0 g/m 3 ) The ^{closer to m 3} ) the drying speed may be slower (up to 60 rpm). As described above, the coating amount and drying rate of the water-soluble polyacrylic resin coating solution must be appropriately adjusted to improve processability.

For example, the drying hood may include a preheating unit, a first drying unit, and a second drying unit, and a temperature of each of the preheating unit and the second drying unit may be lower than a temperature of the first drying unit. Specifically, the drying hood may include a first hood functioning as a preheating unit, a second hood functioning as a drying unit, and a third hood functioning as a drying unit, wherein the water-soluble polyacrylic resin coating solution is coated with biodegradation. The film may be dried while sequentially passing through the first hood (preheating unit), the second hood (first drying unit), and the third hood (second drying unit). In addition, a temperature of the first hood (preheating unit) may be lower than a temperature of the second hood (first drying unit). When the temperature of the first hood (preheating unit) is lower than the temperature of the second hood (first drying unit), drying can proceed without thermal deformation such as shriveling or opaqueness of the biodegradable film. For example, the temperature of the first hood (preheating unit) may be about 60°C, and in this case, the temperature of the second hood (the first drying unit) may be about 80°C, and the third hood (second drying unit) may have a temperature of about 80°C. The temperature of part) may be about 60 °C. Since the biodegradable film is very easily thermally deformed at a temperature exceeding 80°C, a process of preheating at a temperature of about 60°C to 70°C may be very important. That is, if there is no first hood (preheating unit), a film in a shrunken form or an opaque form may be obtained after drying, which may be undesirable. That is, since the drying hood includes a preheating unit (first hood) and a drying unit (second hood and third hood) that satisfy the temperature conditions, the moisture barrier biodegradable film according to an embodiment may be transparent. .

For example, the drying hood includes a first hood (preheating unit), a 2A hood (1A drying unit), a 2B hood (1B drying unit), and a third hood (second drying unit), and the first The temperature of each of the hood (preheating unit) and the third hood (second drying unit) may be lower than the temperature of each of the hood 2A (the drying unit 1A) and the hood 2B (the drying unit 1B). Specifically, the temperature of the first hood (preheating unit) may be about 60 °C, and the temperature of each of the 2A hood (1A drying unit) and the 2B hood (2B drying unit) may be about 80 °C. and the temperature of the third hood (second drying unit) may be about 60°C.

For example, the drying hood may include a first hood (preheating unit), 2A hood (1A drying unit), 2B hood (1B drying unit), 2C hood (1C drying unit), and a third hood (second drying unit), and the temperature of each of the first hood (preheating unit) and the third hood (second drying unit) is the 2A hood (1A drying unit), the 2B hood (1B drying unit) and It may be lower than the temperature of each of the 2C hood (1C drying unit). Specifically, the temperature of the first hood (preheating unit) may be about 60° C., and the 2A hood (1A drying unit), 2B hood (1B drying unit), and 2C hood (1C drying unit) ) each temperature may be about 80 ℃, the temperature of the third hood (second drying unit) may be about 60 ℃.

A temperature of the first hood (preheating unit) may be in a range of 60°C to 70°C. When the temperature of the first hood (preheating unit) is less than 60°C, the function as a preheating unit cannot be performed, resulting in the same result as drying the biodegradable film at a high temperature of 80°C without preheating (thermal deformation of the biodegradable film) ) may appear, and when the temperature of the first hood (preheating unit) exceeds 70°C, there is little difference in temperature between the preheating unit and the first drying unit, so thermal deformation of the biodegradable film is highly likely to occur. it may not be

In the case of a polypropylene resin film, which is widely used as a packaging film even today, thermal deformation does not occur even at a high temperature such as 120 ° C. is different, a preheating process is required to improve processability without causing thermal deformation, and temperature control between the preheating process and the subsequent drying process is also important. In addition, the speed in the drying process needs to be appropriately adjusted have.

Meanwhile, in order to further improve processability, the water-soluble polyacrylic resin coating solution may further include alcohol. In this case, the drying process may occur more quickly, which may be very advantageous in terms of fairness. Since the alcohol is all volatilized during the drying process, it may have no effect on the biodegradability and eco-friendliness of the finally obtained film.

The biodegradable film may be a polylactic acid resin film, a polybutylene adipate-co-terephthalate resin film, a polycaprolactone resin film, or a polybutylene succinate resin film, as described above.

The water-soluble polyacrylic resin coating solution may further include an antifoaming agent, a pH adjusting agent, or a combination thereof, if necessary, as described above.

A method for producing a moisture barrier biodegradable film according to another embodiment comprises: coating a water-soluble urethane resin coating solution on the water-soluble coating layer; And after coating the water-soluble urethane resin coating solution may further include the step of drying it.

The water-soluble urethane resin coating solution may include 20 wt% to 30 wt% of the water-soluble urethane resin based on the total amount of the coating solution. That is, the water-soluble urethane resin coating solution may be composed of 20 wt% to 30 wt% of the water-soluble urethane resin and 70 wt% to 80 wt% of a solvent such as water. When the water-soluble urethane resin is used in the water-soluble urethane resin coating solution included in the above range, it is possible to simultaneously achieve eco-friendly properties and high barrier performance against moisture.

In the step of coating the water-soluble urethane resin coating solution, the coating amount of the water-soluble urethane resin coating solution may be 0.5 g/m ³ to 3.0 g/m ³ . When the coating amount of the coating solution is within the above range, the coating amount is appropriate, so that the coating is performed smoothly, and the barrier performance against moisture can be excellent.

For example, the coating amount of the water-soluble urethane resin coating solution may be less than the coating amount of the water-soluble polyacrylic resin coating solution. For example, the thickness of the protective layer including the water-soluble urethane resin may be thinner than the thickness of the water-soluble acrylic coating layer including the water-soluble polyacrylic resin. In this case, it is not only advantageous for molding, but also it is possible to prepare a film having moisture barrier properties optimized for packaged food because the thickness of the water-soluble acrylic coating layer and the protective layer can be easily controlled.

In other words, the coating amount of the water-soluble polyacrylic resin coating solution is 1.0 g/m ³ to 4.0 g/m ³ , such as 1.0 g/m ³ to 3.0 g/m ³ , and the coating amount of the water-soluble urethane resin coating solution is 0.5 g /m ³ to 3.0 g/m ³ , for example, 0.5 g/m ³ to 2.0 g/m ³ may be, and within this coating amount, it is easy to control the coating amount, so it is easy to control the thickness of the coating layer. Accordingly, it is possible to implement an optimal moisture barrier biodegradable film.

The water-soluble urethane resin coating solution may further include a slip agent, an antifoaming agent, a pH adjusting agent, or a combination thereof, as necessary, as described above.

Another embodiment provides a moisture barrier biodegradable film prepared by the above manufacturing method.

Another embodiment provides a wrapping paper comprising the moisture barrier biodegradable film.

The wrapping paper may be a wrapping paper for food, for example, a wrapping paper for vegetables, a wrapping paper for fruits (a wrapping paper for bananas), a wrapping paper for a cake, a wrapping paper for a sandwich, a wrapping paper for a hamburger, a wrapping paper for gimbap or a wrapping paper for bakery products, etc. It may be.

Another embodiment provides a sticker including the moisture barrier biodegradable film.

Hereinafter, preferred embodiments of the present invention will be described. However, the following examples are only preferred examples of the present invention, and the present invention is not limited by the following examples.

(Production Example)

Preparation of moisture barrier biodegradable film

Preparation Example 1

After coating a water-soluble polyacrylic resin coating solution (50% by weight of water, 50% by weight of polyacrylic resin; pH 9.0) on a polylactic acid resin film (Natureworks) by gravure coating, a drying hood with a length of 5m (No. 1 hood, No. 1) 2A hood, 2B hood, and 3rd hood) were passed through at a speed of 70 rpm to dry (1st hood (preheating part): 60°C, 2A hood (1A drying part): 80°C, 2B hood ( 1B drying part): 80° C., third hood (second drying part): 60° C.) to prepare a transparent moisture barrier biodegradable film (polylactic acid resin film/water-soluble acrylic coating layer). For the spreadability of the coating solution, a smoothing bar was installed to physically improve the spreadability. The coating amount of the water-soluble polyacrylic resin coating solution was 2.0 g/m ³ .

Preparation 2

It was the same as in Preparation Example 1, except that the coating amount of the water-soluble polyacrylic resin coating solution was 2.5 g/m ^{3 .}

Preparation 3

The same as in Preparation Example 1, except that the coating amount of the water-soluble polyacrylic resin coating solution was 3.0 g/m ^{3 .}

Preparation 4

It was the same as in Preparation Example 1, except that the temperature of the first hood (preheating unit) was set to 55°C.

Preparation 5

Except that the temperature of the first hood (preheating unit) was 80°C and the temperature of the 2A hood (1A drying unit) and the 2B hood (1B drying unit) was 60°C, The same was done.

Preparation 6

A water-soluble urethane resin coating solution (70 wt% water, 30 wt% urethane resin) was coated on the water-soluble coating layer constituting the moisture barrier biodegradable film of Preparation Example 1 in a gravure coating method, and dried under the same drying conditions to obtain a protective layer A moisture barrier biodegradable film (polylactic acid resin film/water-soluble acrylic coating layer/protective layer) was prepared in the same manner as in Preparation Example 1 except for the above. The coating amount of the water-soluble urethane resin coating solution was 1.0 g/m ³ .

Preparation 7

It was the same as in Preparation Example 4, except that the moisture barrier biodegradable film of Preparation Example 2 was used instead of the moisture barrier biodegradable film of Preparation Example 1.

Preparation 8

It was the same as in Preparation Example 4 except that the moisture barrier biodegradable film of Preparation Example 3 was used instead of the moisture barrier biodegradable film of Preparation Example 1.

Comparative Preparation Example 1

Only polylactic acid resin film (Nature Works) was used.

Comparative Preparation Example 2

A polypropylene resin film (OPP30/CPP30; Yulchon Chemical) was used.

(evaluation)

Transparency and Appearance Evaluation

The transparency and shape (flatness) of the biodegradable films according to Preparation Examples 1 to 8, Comparative Preparation Example 1 and Comparative Preparation Example 2 were visually checked, and the results are shown in Table 1 below.

Water permeability evaluation

After each banana was packaged with a biodegradable film according to Preparation Examples 1 to 3, Preparation Examples 6 to 8, Comparative Preparation Example 1 and Comparative Preparation Example 2, the moisture permeability of the film was measured (WTR Test Report (v1) .3.2.0), SYSTECH illinois Model 8001, Using Method: ASTM D3985, ASTM F1927, ASTM F1307), and the results are shown in Table 1 below. Films according to Preparation Examples 4 and 5 were opaque and did not have a flat shape, so were excluded from the water permeability evaluation.

transparency shape Water permeability (g/m ² *day) Preparation Example 1 Transparency flat 100 Preparation 2 Transparency flat 75 Preparation 3 Transparency flat 60 Preparation 4 opacity dent - Preparation 5 opacity dent - Preparation 6 Transparency flat 50 Preparation 7 Transparency flat 30 Preparation 8 Transparency flat 20 Comparative Preparation Example 1 Transparency flat 600 Comparative Preparation Example 2 Transparency flat 20

From Table 1, it can be seen that the preheating process and temperature conditions in the drying process have a great effect on the transparency and shape of the film. In addition, it can be confirmed that the moisture barrier biodegradable film according to an embodiment has a significantly lower moisture permeability compared to the conventional biodegradable film, and thus the barrier properties against moisture are greatly increased. In addition, by adding a protective layer, the moisture permeability can be further lowered to the same level as that of the polypropylene resin film, and it can be confirmed that the moisture permeability can be adjusted by adjusting the thickness of the water-soluble acrylic coating layer and the protective layer, Accordingly, it can be inferred that a biodegradable film having an optimal moisture permeability can be prepared.

Storage stability evaluation

After packaging the same French croissant (manufactured by Einz Food) with biodegradable films according to Preparation Examples 1 to 3, Preparation Examples 6 to 8, Comparative Preparation Example 1 and Comparative Preparation Example 2, leave at room temperature for the 5th day And on the 6th day, the properties of the French croissant phase were visually observed (manufactured on the 1st day), and the number of general bacteria (colony count) was tested by a standard plate method, and the results are shown in Table 2 below. If the number of normal bacteria was 24000 CFU/g (mL) or less, it was marked as good, and if the number of normal bacteria was more than 24000 CFU/g (mL), it was marked as bad. Films according to Preparation Examples 4 and 5 were not used as packaging materials because they were opaque and did not have a flat shape, so they were excluded from evaluation. The calculation method of the number of general bacteria (the number of colonies) according to the standard plate method was according to Equation 1 below.

[Equation 1]

N (number of colonies) =

(N = number of bacterial colonies per g or mL of meat

ΣC = sum of colonies counted across all plates

n1 = number of plates counted at the first dilution

n2 = number of plates calculated at the second dilution factor

d = dilution of plate calculated from first dilution)

appearance Normal bacteria count (CFU/g(mL)) safety factor Day 5 Day 6 Day 5 Day 6 Preparation Example 1 Good Good Good Good 0.8 Preparation 2 Good Good Good Good Preparation 3 Good Good Good Good Preparation 6 Good Good Good Good Preparation 7 Good Good Good Good Preparation 8 Good Good Good Good Comparative Preparation Example 1 error error error error Comparative Preparation Example 2 Good Good Good Good

As shown in Table 2, it can be seen that the film according to one embodiment has storage stability equivalent to that of the conventional polypropylene film. That is, it can be confirmed that the film according to one embodiment is transparent, has eco-friendliness, and has storage stability equivalent to that of the conventional polypropylene film in terms of functionality, and thus can cope with environmental problems that are becoming increasingly important. It can be usefully used as a packaging material.

The present invention is not limited to the above embodiments, but can be manufactured in various different forms, and those of ordinary skill in the art to which the present invention pertains can take other specific forms without changing the technical spirit or essential features of the present invention. It will be understood that it can be implemented as Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

1 biodegradable film
2 Water-soluble acrylic coating layer
3 protective layer
4 Water-soluble polyacrylic resin coating solution
10 paper feed
20 preheating part
30 first drying unit
40 second drying unit
50 winding

Claims (12)

a biodegradable film composed only of a polylactic acid resin film, a polybutylene adipate-co-terephthalate resin film, a polycaprolactone resin film or a polybutylene succinate resin film;
a water-soluble acrylic coating layer positioned on the biodegradable film; and
A protective layer positioned on the water-soluble acrylic coating layer,
The water-soluble acrylic coating layer includes a water-soluble polyacrylic resin,
The protective layer includes a urethane resin,
The thickness of the protective layer is thinner than the thickness of the water-soluble acrylic coating layer moisture barrier biodegradable film.
In claim 1,
The water-soluble acrylic coating layer is a moisture barrier biodegradable film further comprising an antifoaming agent, a pH adjusting agent, or a combination thereof.
In claim 1,
The protective layer is a moisture barrier biodegradable film further comprising a slip agent.
In claim 1,
The protective layer is a moisture barrier biodegradable film further comprising an antifoaming agent, a pH adjusting agent, or a combination thereof.
In claim 1,
The moisture barrier biodegradable film further comprises a printed layer between the water-soluble acrylic coating layer and the protective layer.
In claim 1,
The moisture barrier biodegradable film is a moisture barrier biodegradable film having a moisture permeability ^{of 50 g / m 2} *day to 110 g / m ^{2 *day.}
In claim 1,
The moisture barrier biodegradable film is a moisture barrier biodegradable film having a moisture permeability ^{of 10 g/m 2} *day to 70 g/m ^{2 *day.}
In claim 1,
The moisture barrier biodegradable film is a water barrier biodegradable film that is a transparent moisture barrier biodegradable film.
A wrapping paper comprising the moisture barrier biodegradable film according to any one of claims 1 to 8.
In claim 9,
The wrapping paper is a packaging paper for food.
In claim 10,
The food is a wrapping paper comprising vegetables, fruits, cakes, sandwiches, hamburgers, gimbap or bakery products.
A sticker comprising the moisture barrier biodegradable film according to any one of claims 1 to 8.

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