KR102636208B1 - Biodegradable packaging with enhanced degradability - Google Patents

Abstract

The present invention relates to a biodegradable packaging material with enhanced degradability, in which a coating layer with waterproof and antibacterial activity is formed on recycled paper, etc., and a decomposition accelerator is further included inside the coating layer to promote decomposition above a certain temperature. It is characterized by making it possible.
The coating layer is manufactured including a natural product-derived extract and gelatin with antibacterial activity, and further includes a decomposition accelerator containing a biodegradable agent inside the temperature-sensitive polymer capsule, thereby promoting decomposition at a certain temperature. do. The eco-friendly biodegradable packaging material of the present invention is capable of biodegradation without residue even without the addition of inorganic polymers, and since the biodegradant is located inside the temperature-sensitive polymer capsule, biodegradation of the container is delayed as much as possible until heat is applied for decomposition. This can significantly extend the storage period of the container.

Description

Biodegradable packaging with enhanced degradability}

The present invention relates to a biodegradable packaging material with enhanced degradability, in which a coating layer with waterproof and antibacterial activity is formed on recycled paper, etc., and a decomposition accelerator is further included inside the coating layer to promote decomposition above a certain temperature. It is characterized by making it possible.

Packaging materials are used to refer to anything used to temporarily store items mounted inside, and are mainly used in the packaging of food. As simple examples of food packaging materials, you can consider plastic bags, Styrofoam packages, and paper wrappers that are commonly found in everyday life. Food packaging materials can be used to store delivered food, etc., and have the advantage of being easy to use and dispose of.

Food packaging for foods or foods with a lot of moisture or oil, such as fruits, vegetables, bread, cookies, chicken, and ice cream, often causes moisture or oil to soak into the packaging, tearing the packaging, and contaminating the food. In particular, in the case of fresh food packaging materials that store fresh foods such as fruits and vegetables, the freshness of the food may be impaired or become soggy due to water droplets generated from the temperature difference between the food and the atmosphere and moisture from the food itself. Not only did it have a negative effect on the material itself, but in the case of paper packaging, problems such as the packaging material becoming wet and its durability deteriorating occurred.

To compensate for this problem, packaging materials with physical properties such as moisture resistance, water resistance, and oil resistance are being developed, and packaging materials using plastic are commonly used. However, some food packaging materials including plastic generate environmental hormones during the disposal process. Simple landfilling can also cause soil contamination.

Plastic is a material widely used around us because it is stable and has a low specific gravity. Plastic, a stable material, accumulates without change when discharged into the natural environment. In addition, due to its small specific gravity, the volume occupancy rate is higher than that of waste of the same weight, and the problem of securing a treatment plant continues to arise.

Recently, environmental problems, such as the average temperature of the Earth's atmosphere rising due to the greenhouse effect caused by global warming and the occurrence of abnormal climates, continue to become issues around the world. In Korea, environmental problems such as yellow dust, fine dust, and air pollution, which are directly related to the health of all citizens, are emerging as major social problems that need to be solved, and are attracting attention as a sustainable topic.

As interest in environmental pollution increases, efforts are continuing to modify commonly used packaging materials in an environmentally friendly manner.

Korean Patent Publication No. 10-1511333

The present invention was developed to solve the above-mentioned technical problems, and its purpose is to provide an eco-friendly, biodegradable packaging container.

In addition, the purpose of the present invention is to provide a coating composition that exhibits waterproofing and antibacterial effects when treated on the surface of a paper packaging material, and an eco-friendly, biodegradable packaging container treated with the same.

The present invention relates to an eco-friendly biodegradable packaging container. The eco-friendly biodegradable packaging container forms a coating layer with waterproof and antibacterial activity on the surface of recycled paper, and the storage period of various items including food, especially fresh food, is loaded therein. And storage convenience has been improved.

In the present invention, the coating layer may be manufactured including one or more selected from the group consisting of cellulose, starch, and protein.

*The coating material is composed of ingredients that are completely harmless to the human body, and can be characterized as being naturally decomposed and having little impact on the environment.

In addition, the cellulose or starch constituting the coating material is not particularly limited in terms of raw materials, and those skilled in the art can refer to prior art to the extent that it does not impair the technical idea of the present invention. For example, the starch may be starch derived from corn or the like.

In the same context, the protein contains one or more types of amino acids, and those skilled in the art can freely modify or apply conventional techniques without damaging the technical idea of the present invention. However, as an example of a preferred protein, gelatin You can consider using .

In the present invention, the coating layer may be manufactured containing extracts derived from natural products and gelatin with antibacterial activity.

Specifically, gelatin can be obtained from collagen through a hydrolysis reaction. When an acid is used as the hydrolyzing agent, it is called acid-treated gelatin, and when a base is used, it is called base-treated gelatin. On the other hand, gelatin obtained using acids and bases is also called positive-treated gelatin. In addition, when additional organic chemical reactions are performed on the amino group of gelatin, it is called chemically-treated gelatin. It is preferred that acid-treated gelatin or base-treated gelatin is used in the coating material of the present invention.

The coating layer of the present invention is manufactured containing antibacterial substances derived from natural products so that it can have antibacterial activity itself, and the antibacterial substances are composed of only those derived from natural products so that it can be used as a packaging material for food, so that it can be used as a packaging material for food. It is characterized by the exclusion of synthetic chemicals.

Specifically, the antibacterial substance is one or more natural products selected from the group consisting of ginger ( Zingiber officinale ), thyme ( Thymus vulgaris ), gracilaria verrucosa , sage ( Salvia officinalis ), Phellodendron amurense , and cinnamon ( Cinnamomum Schaeff). It may contain extracts of In the present invention, ginger, thyme, ginger, sage, yellow white and cinnamon were mixed at a weight ratio of 1:1:1:1:3:1, then refluxed and extracted with 80% ethanol at 90°C for 4 hours, and then concentrated under reduced pressure. The extract prepared was used. Each of the above-mentioned natural products was most effective when the above-mentioned ratio was observed. If the ratio of each natural product was varied or the extract was prepared by excluding one or more extracts, the antibacterial activity was not only inhibited, but it also prevented souring of fresh foods. It was confirmed that the ability to do so was deteriorating.

Meanwhile, the addition of a phosphoric acid-based compound may be considered to provide sufficient strength to the coating layer. When a phosphoric acid-based compound is added, the cross-linking reaction between gelatin molecules is promoted, and as a result, the time required for hydrolysis of the coating layer is relatively delayed. In addition, acceleration of the crosslinking reaction as described above can increase the density of the coating layer, thereby increasing the waterproofness and durability of the coating layer. Meanwhile, the increase in cross-linking reaction between gelatin molecules is also the cause of improvement in the mechanical properties (e.g., resistance to external force) of the coating layer.

In detail, the phosphoric acid-based compound used in the coating layer of the present invention may include an aliphatic sugar alcohol moiety. By including an aliphatic sugar alcohol moiety, it is possible to enjoy the effect of promoting the cross-linking reaction between gelatin molecules. As a preferred example of the sugar alcohol moiety, one or more sugar alcohol moieties selected from the group consisting of erysitol, arabitol, ribitol, xylitol, mannitol, sorbitol, galactitol, puchitol, and inositol may be considered, It is more preferable to include an inositol moiety from the viewpoint of being able to provide more hardness, and it is more preferable to include a sorbitol moiety from the viewpoint of being able to provide comparative softness.

In the present invention, a mixture of inositol moiety and sorbitol moiety at a weight ratio of 2:3 was used. At this time, it was possible to secure sufficient durability so that the packaging material would not be destroyed by internal or external stimuli that may occur during storage and distribution, and at the same time, even if it was coated on relatively flexible paper, it was possible to prevent the phenomenon of separation between the paper and the coating layer. When the ratio of the sorbitol moiety increases, sufficient hardness cannot be secured, resulting in partial destruction of the coating layer due to friction with the internal article, and when the ratio of the inositol moiety increases, the phenomenon of separation of the paper and the coating layer is observed. It has been done.

On the other hand, if the phosphoric acid-based compound is excessively included in the coating layer, the coating layer becomes acidic and there is a risk of corrosion of the contents of the part in contact with the coating layer, and if it is included in a trace amount, the mechanical properties (e.g., maximum response, tensile strength, etc.) are affected. This may not be done sufficiently. From the viewpoint of simultaneously alleviating the two problems described above, it is preferable that 2.5 to 3 parts by weight of the phosphoric acid-based compound be included, based on 100 parts by weight of gelatin.

The coating liquid composition for forming the waterproof and antibacterial coating layer of the present invention contains 80 to 120 parts by weight of purified water, 25 to 50 parts by weight of glycerin, 10 to 20 parts by weight of an antibacterial material derived from natural products, and 2.5 to 2.5 to 2.5 to 2.5 parts by weight of a phosphoric acid-based compound, based on 100 parts by weight of gelatin. It may be manufactured containing 3 parts by weight, and in one embodiment of the present invention, to form a coating layer, based on 100 parts by weight of gelatin, 100 parts by weight of purified water, 30 parts by weight of glycerin, 15 parts by weight of an antibacterial material derived from natural products, and the phosphoric acid system. A waterproof and antibacterial coating layer composition was prepared by mixing 3 parts by weight of the compound, but it is not limited thereto.

Meanwhile, in the eco-friendly biodegradable packaging material of the present invention, the thickness of the waterproof and antibacterial coating layer is preferably between 0.1 mm and 0.25 mm. For example, if the thickness of the coating layer is 0.1 mm or less, the coating layer can be easily damaged by the projection of external force. Conversely, if the thickness of the coating layer exceeds 0.25 mm, it becomes necessary to use additional adhesive to effectively form the coating layer. Therefore, from the viewpoint of securing appropriate mechanical properties as a coating layer and not requiring a separate adhesive, it is desirable to satisfy the above-mentioned numerical range. In addition, as an extension of the same viewpoint, it is more preferable that the thickness of the coating layer is between 0.1 mm and 0.15 mm.

As another embodiment of the present invention, the coating layer may be set to promote decomposition when a certain temperature is reached by further including a decomposition accelerator containing a biodegradable agent inside the temperature-sensitive polymer capsule.

At this time, it is preferable that at least one of the temperature-sensitive polymer capsules containing the biodegradable agent has at least one side exposed to the outer surface of the coating layer.

In the present invention, the biodegradable agent is preferably a fatty acid ester polymer.

In the present invention, the temperature-sensitive polymer is poly(N-isopropylacrylamide, PNIPAAm), poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide)(Poly (ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide), PEO-PPO-PEO) and polyethylene glycol-polylactic-co-glycolic acid (poly(ethylene glycol)- poly(lactic-co) -glycolic acid), PEG-PLGA) It may be one or more selected from the group consisting of polymers, and specifically may be composed of PLGA-PEG-PLGA polymers, but is not limited thereto.

PEG-PLGA polymer is a substance that can be degraded in the body without causing toxicity.

In 1997, research began on polymers that could exhibit temperature-sensitive gelation while being biodegradable, low in toxicity, and long-term. Among them, polylactic-co-glycolic acid (polylactic-co-glycolic acid), a hydrophobic, biodegradable polymer linked by ester bonds, was developed. Studies have been conducted to create a degradable temperature-sensitive polymer by combining poly(lactic-co-glycolic acid, PLGA) with poly(ethylene glycol, PEG), a hydrophilic polymer.

In particular, research has been conducted on polymers of the PLGA-PEG-PLGA type, which have PLGA in the core and a curved PEG shell is exposed to the outside, forming micelles (capsules). As concentration and temperature increase, the number of micelles and the number of linked micelle groups increase, aggregation occurs, and their packing progresses to form a stable gel. However, as the temperature rises further, the hydrophobic PLGA chain shrinks hard and at the same time, dehydration occurs in the PEO chain, and the shrunken micelles coagulate and condense, causing the biodegradable agent contained inside the micelle (capsule) to be released. Upon exposure, decomposition of the coating layer begins.

In other words, in the present invention, when the product loaded inside the container is exposed to an environment above a certain temperature in the process of processing it as waste after the storage and distribution of the product is completed, the structure of the temperature-sensitive polymer capsule is changed and the biodegradable agent contained therein is exposed, thereby forming a coating layer. It is characterized by the start of decomposition.

Therefore, as described above, by including a temperature-sensitive polymer capsule structure inside the coating layer, the biodegradation process can be delayed as much as possible during the storage and distribution of the product, which has the advantage of enabling long-term storage of the packaging material.

The decomposition accelerator in the form of microcapsules is preferably manufactured in an amount of 1 to 2 parts by weight based on 100 parts by weight of gelatin, and in the present invention, it was manufactured in an amount of 1.5 parts by weight based on 100 parts by weight of gelatin. This is in consideration of productivity in terms of cost while obtaining sufficient decomposition promotion effect.

Meanwhile, this specification includes the steps of preparing packaging materials; Forming a coating layer on one or both sides of the packaging material; and processing the packaging material on which the coating layer is formed into the form of a packaging container. A method for manufacturing an eco-friendly, biodegradable packaging container is further disclosed.

Specifically, the step of forming the coating layer preferably includes preparing a coating solution, forming a coating layer, and attaching the coating layer.

The step of attaching the coating layer involves placing the coating layer on one side of the packaging material and heating it for a certain period of time, and is preferably performed for about 10 to 30 minutes at a temperature between 55°C and 65°C.

Heating in this step induces evaporation of moisture contained in the coating layer.

On the other hand, when the base layer and the coating layer located on one side of the base layer are heated for less than 10 minutes at a temperature of less than 55° C., the adhesion between the coating layer and the paper as a packaging material may not be sufficiently achieved. Conversely, when heated for more than 30 minutes at a temperature exceeding 65°C, the function of the coating layer may be damaged due to excessive shrinkage or destruction of the coating layer.

The packaging material with the above-mentioned coating layer can be processed into various forms to produce eco-friendly, biodegradable packaging containers. For example, it can be processed into a box shape so that various foods, including fresh foods, can be stored and distributed inside the container, and the freshness of fresh foods inside the container can be visually confirmed and the fruit can be prevented from getting soggy due to moisture, etc. One or more holes can be formed (Figures 1 to 3).

Through the adoption of the above-described means, the present invention is composed of biodegradable materials such as paper, gelatin, and a decomposition accelerator, and the eco-friendly biodegradable packaging material of the present invention is biodegradable without residue even without the addition of inorganic polymers. .

In addition, the decomposition accelerator of the present invention can significantly extend the storage period of the container by delaying biodegradation of the container as much as possible until the biodegradation agent is located inside the temperature-sensitive polymer capsule until exposed to high temperatures above a certain temperature.

Additionally, according to the present invention, a coating layer can be formed on one side of a packaging material such as paper without the use of a separate surfactant or adhesive.

The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention.

1 to 3 show examples of packaging containers manufactured according to an embodiment of the present invention.

The terms used in this application are only used to describe specific examples. Therefore, for example, a singular expression includes a plural expression, unless the context clearly requires it to be singular. In addition, terms such as “include” or “equipped” used in the present application are used to clearly indicate the presence of features, steps, functions, components, or combinations thereof described in the specification, and are not used to indicate other features. It should be noted that it is not used to preliminarily rule out the existence of any elements, steps, functions, components, or combinations thereof.

Meanwhile, unless otherwise defined, all terms used in this specification should be viewed as having the same meaning as generally understood by those skilled in the art to which the present invention pertains. Therefore, unless clearly defined in this specification, specific terms should not be interpreted in an overly idealistic or formal sense.

In each description of this specification, eco-friendliness is an abbreviated term for environmentally friendly characteristics. From a technical perspective, eco-friendliness means that the raw materials and energy consumed to produce a specific product can be saved, that recycling of a specific product can be promoted without additional resource consumption (or with only minimal consumption of resources), or that a specific product can be recycled This means that the disposal is easily carried out without consuming additional resources, or that the generation of environmental pollutants is small or absent during the disposal process.

In addition, in the description of this specification, eco-friendliness can be understood as being in the same context as sustainable development. This is because the use of eco-friendly products can be considered as a way to enable sustainable development. Therefore, even if not explicitly stated, guaranteeing eco-friendliness should be understood as entailing contribution to sustainable development.

In each description of this specification, food packaging material is a general term for materials used for storing, distributing, packaging, or dividing food. At this time, it should be understood that the shape and characteristics of the food are not specifically defined, and that there are no separate restrictions as long as it is edible. For example, the food packaging material of the present invention can be used to store solid food or liquid food. In one embodiment of the present invention, fresh food is mainly described among foods, but it is not limited thereto.

In addition, in the description of this specification, food packaging material is a term indicating a material as described above, but the use of the term should not necessarily be understood as limited to 'raw materials' used in the production of food packaging containers. This is because the food packaging material of the present invention can itself take on a specific appearance. However, it should be noted that the characteristics of the food packaging material of the present invention are not limited by its appearance.

Hereinafter, the present invention will be described in detail by examples. However, the following examples are merely illustrative of the present invention, and the present invention is not limited by the following examples.

Example 1. Preparation of packaging material with waterproof and antibacterial coating layer

In order to manufacture the eco-friendly, biodegradable packaging container of the present invention, a waterproof and antibacterial coating layer was formed on a packaging material made of recycled paper.

The coating layer was made by uniformly spreading the waterproof and antibacterial coating layer composition to a thickness of about 2 mm, drying it at room temperature for 12 hours to obtain a thin film, placing the thin film on one side of a packaging material made of recycled paper, and heating it at 60 ° C. for about 15 minutes to obtain a thin film. Formed to be 0.1 to 0.15 mm, the waterproof and antibacterial coating layer composition is prepared by mixing 100 parts by weight of gelatin, 100 parts by weight of purified water, 30 parts by weight of glycerin, 15 parts by weight of an antibacterial material derived from natural products, and 3 parts by weight of the phosphoric acid-based compound. Manufactured.

As described above, the natural product-derived antibacterial substance is prepared by mixing ginger, thyme, turmeric, sage, yellowtail, and cinnamon at a weight ratio of 1:1:1:1:3:1, respectively, and then reacting with 80% ethanol at 90°C for 4 minutes. The product obtained by reflux extraction for a period of time and then concentrated under reduced pressure was used, and the phosphoric acid-based compound was used as a mixture of inositol moiety and sorbitol moiety in a weight ratio of 2:3.

Example 2. Manufacturing of packaging material with enhanced biodegradability

Although the packaging material of Example 1 was composed only of biodegradable materials, a packaging material containing a decomposition accelerator to enhance biodegradability was manufactured.

Specifically, 35 parts by weight of a temperature-sensitive polymer material (PLGA-PEG-PLGA) is mixed with 25 parts by weight of fatty acid ester polymer (PLA) to encapsulate, and 100 parts by weight of propylene polymer with a weight average molecular weight of 100,000 is encapsulated at about 100°C. After mixing for about 2 minutes, the decomposition accelerator was prepared by rapidly cooling to 5 to 10°C.

At this time, the packaging material of Example 2 of the present invention was manufactured by forming a coating layer in the same manner as in Example 1, except that 1.5 parts by weight of the decomposition accelerator was included relative to 100 parts by weight of gelatin.

Experimental Example 1. Experiment to check water resistance

In order to confirm the waterproofness of the packaging material of the present invention in which the formation of the waterproof and antibacterial coating layer was completed, waterproofness (rainwater method) was performed in accordance with AATCC 35 and KS K 0593.

Briefly, when rainwater was sprayed from a height of 1 foot for 5 minutes, the weight of the absorbent paper attached to the back of the packaging materials of Examples 1 and 2 did not increase at all, so it passed the above standard. Even when rainwater was sprayed for 30 minutes, the weight increase of the standard absorbent paper did not exceed 1g, confirming that Examples 1 and 2 of the present invention had very excellent waterproofing properties.

Experimental Example 2. Experiment to confirm antibacterial effect

The packaging material of the present invention and the packaging container using the same are characterized as having waterproof and antibacterial activity, and can be used in the storage and distribution of items with high water content such as fresh food, which can easily create a humid and well-supplied environment. It is characterized by being able to suppress the growth of mold and bacteria.

To confirm this, KSK-0693:2011 was applied to confirm antibacterial properties. Specifically, using Examples 1 and 2 and Comparative Example 1 in which the coating layer was damaged by artificially scratching the surface, Staphylococcus aureus and Escherichia coli to be measured were 1. After inoculating x 10 ⁷ cells and culturing for 20 hours, the reduction rate of bacteriostasis was measured in % and is shown in Table 1 below.

division S. aureus (%) E. coli (%) Example 1 99 99 Example 2 99 99 Comparative Example 1 56 45

As shown in Table 1, the coatings of Examples 1 and 2 of the present invention have excellent antibacterial properties on their own, but it was confirmed that bacteria easily proliferate on the packaging material when the coating layer is damaged. Experimental Example 3. Experiment to confirm biodegradability

The biodegradability of the eco-friendly biodegradable packaging material of the present invention was measured in accordance with KS M3100-1 (ISO14855). The purpose of the above standard is to measure the biodegradability (%) of plastic resin by measuring the amount of carbon dioxide generated under composting conditions. As a comparative example, packaging paper with a plastic coating on the paper surface was used, and the results were compared with Examples 1 and 2 of the present invention. The measurement period was 40 days in total and measurements were taken at 5-day intervals. The results measured for the examples and comparative examples of the same weight are shown in Table 2 below. The values in Table 2 below correspond to the average values of each of the 10 examples 1 and 2 and the 10 comparative examples, and are rounded to two decimal places.

Example 1 Example 2 Comparative example 0.0 0.0 0.0 6.4 6.2 3.8 9.8 9.3 5.8 11.4 12.9 10.9 14.5 25.0 13.0 21.0 31.5 15.7 46.3 64.6 17.3 60.6 73.5 19.8

Referring to Table 2, Examples 1 and 2 showed significantly higher biodegradability compared to Comparative Example, and in particular, in the case of Example 2, it was confirmed that the biodegradation rate gradually accelerated over time.

The description of the present invention described above is for illustrative purposes, and those skilled in the art will understand that the present invention can be easily modified into other specific forms without changing the technical idea or essential features of the present invention. will be. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive. For example, each component described as unitary may be implemented in a distributed manner, and similarly, components described as distributed may also be implemented in a combined form.

The scope of the present invention is indicated by the claims described below, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention.

Claims (1)

It is an eco-friendly, biodegradable packaging material with a coating layer with waterproof and antibacterial activity formed on the surface of recycled paper.
The coating layer contains 80 to 120 parts by weight of purified water, 25 to 50 parts by weight of glycerin, 10 to 20 parts by weight of an antibacterial material derived from natural products, 2.5 to 3 parts by weight of a phosphoric acid-based compound, and 1 to 2 parts by weight of a decomposition accelerator, based on 100 parts by weight of gelatin. Manufactured including,
The antibacterial substances derived from natural products include ginger ( Zingiber officinale ), thyme ( Thymus vulgaris ), gracilaria verrucosa , sage ( Salvia officinalis ), Phellodendron amurense and cinnamon ( Cinnamomum Schaeff ) in a ratio of 1:1:1:1. It is manufactured by mixing and extracting at a weight ratio of :3:1,
The decomposition accelerator contains a fatty acid ester-based biodegradation agent inside a temperature-sensitive polymer capsule, at least part of which is in the form of fine particles,
The temperature-sensitive polymer is poly(N-isopropylacrylamide, PNIPAAm), poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) )-b-poly(propylene oxide)-b-poly(ethylene oxide), PEO-PPO-PEO) and poly(ethylene glycol)-poly(lactic-co-glycolic acid) ), PEG-PLGA), one or more selected from the group consisting of polymers,
Eco-friendly biodegradable packaging material.