Environmentally friendly packaging materials and methods for manufacturing the same

Abstract

The present invention relates to an environmentally friendly packaging material and a manufacturing method thereof. Specifically, the packaging material according to one embodiment of the present invention includes a surface coating layer, a first fiber layer, a second fiber layer, and a sealing coating layer, and thus has high recyclability, is easily decomposed in soil and ocean, and has excellent barrier properties against oxygen and / or moisture, printability, anti-fouling / waterproof properties, sealing properties, etc.

Description

[Technical Field]

[0001] The present invention relates to an environmentally friendly packaging material having a multilayer structure, excellent printability, stain resistance / water resistance, sealing properties, and barrier properties against oxygen and / or moisture, as well as being easily recyclable and biodegradable, and a method for producing the same. [Background technology]

[0002] Generally, packaging materials used to package items such as food, pharmaceuticals, cosmetics, and industrial products consist of a base layer for printing and surface protection, a barrier layer for blocking oxygen and moisture, and an inner layer for storing the contents.

[0003] Conventionally, packaging materials have been manufactured by applying polyethylene terephthalate (PET) film or polypropylene (PP) film to the base layer, aluminum foil or nylon film to the barrier layer, and low-density polyethylene (LDPE) film, linear low-density polyethylene (LLDPE) film, or unoriented polypropylene (CPP) film to the inner layer.

[0004] However, these packaging materials are difficult to recycle. Because they are made of non-biodegradable materials, they do not decompose completely when landfilled, and in some cases, it can take hundreds of years for them to decompose. In particular, they hardly decompose in soil or the ocean, causing serious problems such as air pollution and marine pollution.

[0005] To address the aforementioned problems, environmentally friendly packaging materials have recently been developed that combine easily biodegradable materials (such as polylactic acid (PLA)) with highly recyclable paper, instead of materials that are difficult to decompose, such as PET, nylon, and aluminum.

[0006] However, the biodegradable material has low barrier properties against oxygen and moisture, and the packaging material produced using this has limitations in exhibiting the barrier properties required for packaging materials for foods, cosmetics, pharmaceuticals, etc. In addition, a packaging material in which a biodegradable material and paper are bonded lacks sealing properties, and has the disadvantage that layers made of the biodegradable material and the paper layer are peeled off during its use or processing. In addition, it is also difficult to ensure printability and stain / waterproof properties for design purposes.

[0007] Therefore, while being easily decomposed in soil and the ocean, there is a need for the development of a packaging material with high recyclability and improved performance.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0009] The present invention provides a packaging material with high recyclability, easily decomposed in soil and the ocean, and excellent in barrier properties (gas barrier properties) against oxygen and / or moisture, printability, stain / waterproof properties, sealing properties, etc.

[0010] In addition, the present invention provides a method for manufacturing a packaging material that can efficiently manufacture the packaging material.

Means for Solving the Problems

[0011] According to one aspect of the present invention, in order to solve the above problems, a multilayer packaging material including a surface coating layer, a first fiber layer, a second fiber layer, and a sealing coating layer is provided.

[0012] In one embodiment, the surface coating layer may include one or more selected from the group consisting of aqueous thermosetting acrylic resin, aqueous latex, aqueous modified latex, aqueous urethane resin, and polyethylene emulsion.

[0013] In another embodiment, the first fiber layer includes a primer layer formed on its surface, and the primer layer may include one or more selected from the group consisting of polyvinyl alcohol (PVOH) and modified starch.

[0014] In yet another embodiment, the second fiber layer has a density of 0.8 kg / m³ 3 That's fine too.

[0015] In yet another embodiment, the second fiber layer may contain a portion of the components derived from the sealing coating layer.

[0016] In yet another embodiment, the sealing coating layer may include one or more selected from the group consisting of aqueous thermoplastic acrylic resin, polyhydroxyalkanoate (PHA), and polyethylene emulsion.

[0017] In yet another embodiment, the multilayer packaging material may further include a barrier layer formed between the first fiber layer and the second fiber layer.

[0018] In yet another embodiment, the barrier layer may include a biodegradable resin or a water-soluble resin.

[0019] In yet another embodiment, the barrier layer may contain one or more substances selected from the group consisting of polyhydroxyalkanoates (PHA), polylactic acid (PLA), polyvinyl alcohol (PVOH), ethylene vinyl alcohol (EVOH), polybutylene adipate-co-terephthalate (PBAT), polybutylene succinate (PBS), polycaprolactone (PCL), thermoplastic starch (TPS), cellulose-derived substances, whey protein, soy protein, and wheat protein.

[0020] On the other hand, according to another aspect of the present invention, the material comprises a first fiber layer and a second fiber layer, and has a cobb sizing degree of 25 g / m². 2 • Provide multi-layer packaging materials with a processing time of 30 minutes or less.

[0021] In one embodiment, the multilayer packaging material has an oxygen permeability of 100 cc / m³. 2 • Less than 1 day, with a water permeability of 100 g / m². 2 • It may be less than one day.

[0022] In another embodiment, the multilayer packaging material may have a sealing strength of 1 kgf / 15 mm or more.

[0023] In yet another embodiment, the multilayer packaging material may have a surface energy of 38 dyne / cm or more.

[0024] On the other hand, according to one aspect of the present invention, a method for manufacturing a multilayer packaging material is provided, comprising the steps of: manufacturing a first fiber film by coating one surface surface coating liquid with a first fiber substrate; manufacturing a second fiber film by coating one surface surface sealing coating liquid with a second fiber substrate; and laminating the first fiber film and the second fiber film so that the first fiber substrate and the second fiber substrate face each other.

[0025] In one embodiment, the step of placing a barrier film between the first fiber film and the second fiber film and laminating them may be included.

[0026] In another embodiment, the step of coating the other surface of the first fiber film or the other surface of the second fiber film with a barrier coating liquid may be further included. [Effects of the Invention]

[0027] The packaging material according to the present invention has a specific multilayer structure in which two fiber layers are provided internally, and a surface coating layer and a sealing coating layer are provided externally to the fiber layers, respectively, and therefore has excellent properties such as barrier properties against oxygen and / or moisture, printability, stain resistance / water resistance, and sealing properties.

[0028] Furthermore, the packaging material according to the present invention has a surface coating layer and a sealing coating layer made of an aqueous resin material, and two fiber layers made of paper material, so it is highly recyclable and easily decomposes in soil and the ocean.

[0029] Furthermore, the packaging material according to the present invention is further provided with a barrier layer made of a biodegradable or water-soluble resin material between the two fiber layers, thus exhibiting excellent biodegradability as well as superior barrier properties against oxygen and / or moisture.

[0030] Furthermore, since the packaging material according to the present invention is manufactured using methods such as lamination and extrusion coating, which are applied during the production of plastic films, it offers excellent processability and productivity.

[0031] Therefore, the packaging material according to the present invention can be efficiently used to package a variety of items such as food, pharmaceuticals, cosmetics, and industrial products. [Brief explanation of the drawing]

[0032] [Figure 1] This is a cross-sectional view showing a packaging material according to one embodiment of the present invention. [Figure 2] This is a cross-sectional view showing a packaging material according to another embodiment of the present invention. [Figure 3]This is a cross-sectional view showing a packaging material according to yet another embodiment of the present invention. [Figure 4] This is a cross-sectional view showing a packaging material according to yet another embodiment of the present invention. [Modes for carrying out the invention]

[0033] The present invention will be described below through examples. However, the present invention is not limited to what is disclosed below and can be modified in various forms as long as the essence of the invention remains unchanged.

[0034] In this specification, any description of one component being formed above / below another, or connected or joined to one another, includes all instances where these components are formed, connected, or joined directly or indirectly through other components. Furthermore, the criteria for above / below each component should be understood to vary depending on the direction from which the object is observed.

[0035] In this specification, the word "includes" is used to specify particular characteristics, areas, steps, processes, elements and / or components, and does not exclude the presence or addition of other characteristics, areas, steps, processes, elements and / or components unless otherwise specifically opposed.

[0036] In this specification, terms such as "first," "second," etc., are used to describe various components, and the components are not limited by such terms. Specifically, these terms are used to distinguish one component from another.

[0037] All figures and expressions indicating the amounts of components, reaction conditions, etc., described herein should be understood to be modified by the term "approximately" unless otherwise specified.

[0038] The present invention relates to a packaging material having a specific multilayer structure (for example, including two or more fiber layers) and a method for manufacturing the packaging material by applying a process such as lamination or extrusion coating, and will be specifically described below.

[0039] multilayer packaging material The packaging material according to the present invention includes a surface coating layer, a first fiber layer, a second fiber layer, and a sealing coating layer. Specifically, the packaging material according to the present invention may be a laminated film in which the surface coating layer, the first fiber layer, the second fiber layer, and the sealing coating layer are laminated, or the laminated film may be post-processed as necessary.

[0040] The following provides a detailed explanation of each layer, referring to Figures 1 through 4.

[0041] Surface coating layer A packaging material 10 according to one embodiment of the present invention includes a surface coating layer 11. The surface coating layer 11 serves to enhance the printability (designability), water resistance (waterproofing), and stain resistance of the packaging material 10.

[0042] The surface coating layer 11 can form a film and may contain a substance that has water-soluble properties while exhibiting the water resistance required for the packaging material 10. Specifically, the surface coating layer 11 may contain one or more substances selected from the group consisting of aqueous thermosetting acrylic resin, aqueous latex, aqueous modified latex, aqueous urethane resin, and polyethylene emulsion. The inclusion of a substance with water-soluble properties in the surface coating layer 11 can enhance the recyclability of the packaging material 10. In addition, the surface coating layer 11 may further contain additives such as mineral oil and wax to ensure water resistance and stain resistance.

[0043] The surface coating layer 11 can have a surface energy of 38 dyne / cm or more. Specifically, the surface coating layer 11 can have a surface energy of 38 to 55 dyne / cm, 40 to 55 dyne / cm, 42 to 55 dyne / cm, 44 to 55 dyne / cm, or 46 to 55 dyne / cm. When the surface energy of the surface coating layer 11 is within the above range, it is easy to be printed on the surface coating layer 11, and the printability (designability) of the packaging material 10 can be improved.

[0044] Also, the surface coating layer 11 can have antifouling / waterproof properties in order to enhance the usability, workability, etc. of the packaging material 10. Specifically, the surface coating layer 11 can have a Cobb sizing degree of 30 g / m 2 ·30 min or less. More specifically, the surface coating layer​​​​​​​​​​​​​​​​​​​​​ First fiber layer A packaging material 10 according to one embodiment of the present invention includes a first fiber layer 12. A surface coating layer 11 can be formed on one surface of the first fiber layer 12. These first fiber layers 12 serve to facilitate the formation of the surface coating layer 11 while ensuring the apparent suitability of the packaging material 10.

[0048] The first fiber layer 12 may include paper made from mechanical pulp, semi-chemical pulp, chemical pulp, etc. The paper is not particularly limited and can be manufactured or selected depending on the intended use. Because the first fiber layer 12 includes paper made from the pulp, the packaging material 10 according to the present invention has superior biodegradability and recyclability compared to conventional packaging materials that use synthetic resin substrates such as polyethylene terephthalate (PET) and polypropylene (PP).

[0049] Specifically, the first fiber layer 12 may include water-resistant paper (for example, paper sizing with alkyl ketene dimer (AKD) or aluminum-rosin). Including the water-resistant paper in the first fiber layer 12 prevents the surface coating liquid for forming the surface coating layer 11 from migrating through the paper, thereby facilitating the formation of the surface coating layer 11.

[0050] On the other hand, the first fiber layer 12 may include a primer layer formed on its surface (one side, the other side, or both sides of the first fiber layer 12). By forming a primer layer on the surface of the first fiber layer 12, the adhesion to the surface coating layer 11, the second fiber layer 13, or the barrier layer 15 described later can be enhanced while further improving the oxygen and / or moisture barrier properties of the packaging material 10.

[0051] The primer layer may include commonly known anchor coating agents. Specifically, the primer layer may include one or more selected from the group consisting of polyvinyl alcohol (PVOH) and modified starch.

[0052] Second fiber layer A packaging material 10 according to one embodiment of the present invention includes a second fiber layer 13. A sealing coating layer 14 can be formed on one surface of the second fiber layer 13. These second fiber layers 13 serve to enhance the mechanical strength and smoothness of the packaging material 10 while ensuring a strong internal bond with the sealing coating layer 14.

[0053] The second fiber layer 13 may include paper made from mechanical pulp, semi-chemical pulp, chemical pulp, etc. Specifically, the paper may be one or more selected from the group consisting of white fine paper (imitation paper), colored paper, colored paper, rough paper, medium-quality paper, art paper, snow paper, snow white paper, single-sided art paper, royal art paper, leather paper, laid paper, kraft paper, tracing paper, glassine paper, Tant paper, fancy paper, white cardboard, and photographic paper. Because the second fiber layer 13 includes the paper, the packaging material 10 according to the present invention has superior biodegradability and recyclability compared to conventional packaging materials that use synthetic resin substrates such as polyethylene terephthalate (PET) and polypropylene (PP).

[0054] The second fiber layer 13 has a density of 0.8 kg / m³ 3 The above is also acceptable. Specifically, the density of the second fiber layer 13 is 0.8 to 1.5 kg / m³. 3 , 0.9~1.5kg / m 3 , 1.0~1.5 kg / m 3 , 1.0~1.3 kg / m 3 , or 1.0~1.2 kg / m 3 This may also be the case. If the density of the second fiber layer 13 is within the above range, the fibers within the second fiber layer 13 will have very high bonding strength, which can significantly increase the mechanical strength of the packaging material 10.

[0055] Furthermore, the proportion of softwood fibers in the second fiber layer 13 may be 20-100% of the total fibers within the second fiber layer 13. When the proportion of softwood fibers in the second fiber layer 13 is within the above range, the mechanical strength and density can be increased by increasing the proportion of long fibers in the second fiber layer 13.

[0056] On the other hand, the second fiber layer 13 may contain some components derived from the sealing coating layer 14. Specifically, the second fiber layer 13 may include a composite layer formed by partially impregnating it with the sealing coating liquid for forming the sealing coating layer 14. For example, referring to Figure 2, the second fiber layer 13 may include a paper layer 13a and a composite layer 13b in which components derived from the paper substrate and the sealing coating layer 14 are combined. By including these composite layers 13b, the second fiber layer 13 can exhibit a remarkably high bonding strength with the sealing coating layer 14.

[0057] Sealing coating layer A packaging material 10 according to one embodiment of the present invention includes a sealing coating layer 14. The sealing coating layer 14 is formed on one surface of the second fiber layer 13, thereby enhancing the water resistance, sealing properties, and other functions of the packaging material 10.

[0058] The sealing coating layer 14 is strongly bonded to the second fiber layer 13, thereby enhancing the sealing properties of the packaging material 10. It may contain a water-dispersible and heat-adherent thermoplastic resin (e.g., acrylic resin, polypropylene, etc.). Specifically, the sealing coating layer 14 may contain a substance that is water-soluble or biodegradable while enhancing the sealing properties of the packaging material 10. For example, the sealing coating layer 14 may contain one or more substances selected from the group consisting of aqueous thermoplastic acrylic resin, polyhydroxyalkanoate (PHA), and polyethylene emulsion. The sealing coating layer 14 contains a substance that is water-soluble or biodegradable, which enhances the sealing properties of the packaging material 10 and improves its recyclability.

[0059] The sealing coating layer 14 can have a sealing strength (thermal bonding strength) of 1 kgf / 15 mm or more in order to improve the usability and processability of the packaging material 10. Specifically, the sealing coating layer 14 can have a sealing strength of 1 to 5 kgf / 15 mm, 1.5 to 5 kgf / 15 mm, 2 to 5 kgf / 15 mm, 2.5 to 5 kgf / 15 mm, or 3 to 5 kgf / 15 mm.

[0060] The thickness of these sealing coating layers 14 may be 3-30 μm, 10-30 μm, 13-28 μm, 15-25 μm, or 17-25 μm. By keeping the thickness of the sealing coating layer 14 within the above range, the packaging material 10 can be prevented from becoming unnecessarily thick while ensuring its stain resistance, sealing properties, etc., thereby improving productivity.

[0061] The sealing coating layer 14 may consist of a single layer or two or more layers (for example, a laminated structure of a first sealing coating layer / second sealing coating layer, or a laminated structure of a first sealing coating layer / second sealing coating layer / third sealing coating layer) in order to increase sealing strength.

[0062] Barrier layer The packaging material 10 according to one embodiment of the present invention may further include a barrier layer to enhance its ability to block oxygen and / or moisture.

[0063] Specifically, referring to Figure 3, the barrier layer 15 can be formed between the first fiber layer 12 and the second fiber layer 13. These barrier layers 15 serve to enhance the oxygen and / or moisture barrier properties (gas barrier properties) of the packaging material 10.

[0064] The barrier layer 15 may include a biodegradable resin or a water-soluble resin that can enhance the gas barrier properties of the packaging material 10 while ensuring recyclability and biodegradability. Specifically, the barrier layer 15 may include one or more selected from the group consisting of polyhydroxyalkanoate (PHA), polylactic acid (PLA), polyvinyl alcohol (PVOH), ethylene vinyl alcohol (EVOH), polybutylene adipate-co-terephthalate (PBAT), polybutylene succinate (PBS), polycaprolactone (PCL), thermoplastic starch (TPS), cellulose-derived substances (e.g., nanocellulose, carboxymethylcellulose (CMC), cellulose ether, etc.), whey protein, soy protein, and wheat protein.

[0065] The thickness of these barrier layers 15 may be 3 to 30 μm, 5 to 25 μm, 10 to 25 μm, 15 to 25 μm, or 18 to 25 μm. By having the thickness of the barrier layer 15 within the above range, manufacturing efficiency and productivity can be improved while enhancing the gas barrier properties of the packaging material 10.

[0066] adhesive layer When the packaging material 10 according to the present invention is manufactured by a lamination method, it may further include an adhesive layer that bonds each layer together.

[0067] Specifically, referring to Figure 4a), the adhesive layer 16 can be formed between the first fiber layer 12 and the second fiber layer 13. Also, referring to Figure 4b), the adhesive layer 16 can be formed between the first fiber layer 12 and the barrier layer 15, and between the second fiber layer 13 and the barrier layer 15, respectively. These adhesive layers 16 serve to strongly bond the first fiber layer 12 and the second fiber layer 13, or the first fiber layer 12, the barrier layer 15, and the second fiber layer 13 to each other, thereby improving the usability and processability of the packaging material 10.

[0068] The adhesive layer 16 may include an adhesive substance that can exhibit high adhesive strength without degrading the physical properties of the packaging material 10. Specifically, the adhesive layer 16 may include one or more substances selected from the group consisting of polyhydroxyalkanoate (PHA), polyvinyl alcohol (PVA), ethylene vinyl acetate (EVA), polyolefin resin emulsion, ethylene methyl acrylate (EMA), acrylic resin, and urethane resin.

[0069] The thickness of these adhesive layers 16 may be 1 to 10 μm, 3 to 10 μm, or 5 to 10 μm. By having the thickness of the adhesive layer 16 within the above range, the processability and usability of the packaging material 10 can be improved.

[0070] Physical properties of packaging materials The packaging material according to the present invention includes a first fiber layer and a second fiber layer, and has a cobb sizing degree of 25 g / m². 2 It can exhibit physical properties of 30 min or less. Specifically, the packaging material according to one embodiment of the present invention has a bump size degree of 1 to 30 g / m². 2 • 30 min, 1-25 g / m² 2 30 min, 1-20 g / m 2 • 30 min, 1-14 g / m² 2 30 min, or 1-10 g / m² 2 It may also be 30 min. As long as the bump size is within the above range, the packaging material according to the present invention exhibits high mechanical strength while having excellent oxygen and / or moisture barrier properties.

[0071] The aforementioned cob size degree can be expressed as the amount (weight) of water absorbed by a packaging material of a certain size when a certain amount of water is poured into it for 30 minutes. Specifically, the cob size degree can be calculated by the following formula 1.

[0072] formula 1

[0073] Knob size = (Weight of packaging material after water absorption - Weight of packaging material before water absorption, g) / (Absorption area, m) 2 )

[0074] The packaging material according to the present invention has an oxygen permeability of 100 cc / m³. 2 • Less than 1 day, with a water permeability of 100 g / m². 2 It may be less than 1 day. Specifically, the packaging material according to one embodiment of the present invention has an oxygen permeability of 0.1 to 100 cc / m³ at 23°C and RH 0%. 2 • day, 0.1~50cc / m 2 • day, 0.1~10cc / m 2 • day, 0.1~5cc / m 2 • day, or 0.1-1 cc / m³ 2 It may also be a day. Furthermore, the packaging material according to one embodiment of the present invention has a moisture permeability of 0.1 to 100 g / m² at 37.8°C and RH100%. 2 • day, 0.1-50 g / m² 2 • day, 0.1-10 g / m 2 • day, 0.1-5 g / m² 2 • day, or 0.1-1 g / m² 2 • Day is fine too.

[0075] The packaging material according to the present invention may have a sealing strength (thermal bonding strength) of 1 kgf / 15 mm or more. Specifically, if the packaging material according to one embodiment of the present invention includes a sealing coating layer, the sealing strength of the sealing coating layer may be 1 to 5 kgf / 15 mm, 1.5 to 5 kgf / 15 mm, 2 to 5 kgf / 15 mm, 2.5 to 5 kgf / 15 mm, or 3 to 5 kgf / 15 mm. Because the sealing strength is within the above range, the packaging material according to the present invention has excellent bonding (adhesion) characteristics between each layer (minimizing delamination), thereby improving the usability, processability, and productivity of the packaging material.

[0076] The packaging material according to the present invention may have a surface energy (surface tension) of 38 dyne / cm or higher. Specifically, the packaging material according to one embodiment of the present invention may have a surface energy of 38-55 dyne / cm, 40-55 dyne / cm, 42-55 dyne / cm, 44-55 dyne / cm, or 46-55 dyne / cm. Having the surface energy within the above range provides excellent printability (designability) for the packaging material according to the present invention. These surface energies can be measured with a surface tension measuring pen (e.g., Dynepen).

[0077] The packaging material according to the present invention may have a tensile strength of 8 kgf or more, as measured by universal time testing (UTM, model name 5966) based on ASTM D882. Specifically, the packaging material according to one embodiment of the present invention may have a tensile strength of 8-18 kgf, 8-15 kgf, 10-15 kgf, or 12-15 kgf. Because the tensile strength is within the above range, the packaging material according to the present invention has excellent usability, processability, moldability, etc.

[0078] The packaging material according to the present invention may have a biodegradability of 60% or more, 65% or more, 70% or more, or 75% or more, as measured according to KS M 14855-1. The biodegradability refers to the ratio of the packaging material decomposed to a standard substance (e.g., cellulose) over a certain period of time, and can be calculated by the following formula 2.

[0079] formula 2

[0080] Biodegradation degree (Dt)={((CO2)T-(CO2)B) / ThCO2}×100 (CO2)T: Cumulative amount of carbon dioxide generated from the composting container containing the test material. (CO2)B: Average cumulative amount of carbon dioxide emitted from the inoculant container ThCO2: The theoretical amount of carbon dioxide that can be produced from the test substance. ThCO2=M TOT ×C TOT ×44 / 12 M TOT:Total dry solids (g) of the test substance added to the compost at the start of the test. C TOT : Percentage of organic carbon contained in the total dry solids of the test substance (g / g) 44 / 12: Molecular weight of carbon dioxide and atomic weight of carbon

[0081] The packaging material according to the present invention, as described above, includes a biodegradable or water-soluble surface coating layer, a sealing coating layer, and a barrier layer, as well as relatively easily decomposable first and second fiber layers. Therefore, it is easily decomposed in soil and ocean, demonstrating environmental friendliness. Furthermore, the packaging material according to the present invention also exhibits excellent recyclability. In addition, the packaging material according to the present invention has excellent gas barrier properties due to its barrier layer.

[0082] Therefore, the packaging material according to the present invention can be efficiently used to package a variety of items such as food, pharmaceuticals, cosmetics, and industrial products. For example, the packaging material according to one embodiment of the present invention can be used in pouches for retort foods, lead films for food containers, and the like.

[0083] These packaging materials according to the present invention can be manufactured to have a multilayer structure by applying methods such as lamination and extrusion coating, which will be explained in detail below.

[0084] Manufacturing method for multilayer packaging materials The method for manufacturing packaging materials according to one embodiment of the present invention involves applying lamination and extrusion coating, which are methods applied to the manufacture of plastic films, thereby enabling the efficient production of packaging materials having diverse laminated structures depending on the purpose.

[0085] Specifically, the method for manufacturing packaging material according to the present invention includes the steps of: manufacturing a first fiber film by coating one surface of a first fiber substrate with a surface coating liquid; manufacturing a second fiber film by coating one surface of a second fiber substrate with a sealing coating liquid; and laminating the first fiber film and the second fiber film so that the first fiber substrate and the second fiber substrate face each other. A more detailed explanation of this is as follows.

[0086] To form the aforementioned surface coating layer and first fiber layer, a surface coating liquid is applied to one surface of the first fiber substrate to produce a first fiber film.

[0087] The first fibrous substrate is not particularly limited and includes paper made from pulp, and can be manufactured or selected depending on the intended use.

[0088] Furthermore, the first fiber substrate may be surface-treated with one or more primers selected from the group consisting of polyvinyl alcohol (PVOH) and modified starch.

[0089] The surface coating liquid may include a substance that has water-soluble properties while exhibiting the water resistance required for packaging materials. Specifically, the surface coating liquid may include one or more substances selected from the group consisting of aqueous thermosetting acrylic resin, aqueous latex, aqueous modified latex, aqueous urethane resin, and polyethylene emulsion. In addition, the surface coating liquid may further include additives such as mineral oil and wax, commonly known additives (e.g., polymerization initiators, crosslinking agents, emulsifiers, fillers, antioxidants, smoothing agents, defoaming agents, etc.) and solvents.

[0090] The method for coating one surface of the first fiber substrate with the surface coating liquid is not particularly limited, and methods such as spray coating, spin coating, bar coating, dip coating, and doctor blade coating can be used.

[0091] The coated surface coating liquid can be dried at 80-150°C to produce a first fiber film.

[0092] To form the aforementioned sealing coating layer and second fiber layer, a sealing coating liquid is coated onto one surface of the second fiber substrate to produce a second fiber film.

[0093] The second fibrous substrate may be paper made from mechanical pulp, semi-chemical pulp, chemical pulp, etc. Specifically, the paper may be one or more selected from the group consisting of white fine paper (imitation paper), colored paper, colored paper, rough paper, medium-quality paper, art paper, snow paper, snow white paper, single-sided art paper, royal art paper, leather paper, laid paper, kraft paper, tracing paper, glassine paper, Tant paper, fancy paper, white cardboard, and photographic paper.

[0094] The second fibrous base material has a density of 0.8 kg / m³ 3 (Specifically 0.8~1.5 kg / m 3 , 0.9~1.5kg / m 3 , 1.0~1.5 kg / m 3 , 1.0~1.3 kg / m 3 , or 1.0~1.2 kg / m 3 ) is also acceptable.

[0095] The sealing coating liquid may contain a thermoplastic resin (e.g., acrylic resin, polypropylene, etc.) that can strongly bond with the second fiber substrate to enhance the sealing properties of the packaging material. Specifically, the sealing coating liquid may contain a substance that is water-soluble or biodegradable. For example, the sealing coating liquid may contain one or more selected from the group consisting of aqueous thermoplastic acrylic resin, polyhydroxyalkanoate (PHA), and polyethylene emulsion. In addition, the sealing coating liquid may further contain commonly known additives (e.g., polymerization initiators, crosslinking agents, emulsifiers, fillers, antioxidants, smoothing agents, defoaming agents, etc.) and solvents.

[0096] The method for coating one surface of the second fiber substrate with the sealing coating liquid is not particularly limited, and methods such as spray coating, spin coating, bar coating, dip coating, and doctor blade coating can be used.

[0097] The coated sealing liquid can be dried at 80-150°C to produce a second fiber film.

[0098] Next, the first fiber film and the second fiber film are laminated. Specifically, the first fiber film and the second fiber film are laminated with the first fiber substrate and the second fiber substrate facing each other so that the first fiber layer and the second fiber layer can be formed inside the packaging material. Here, an adhesive can be coated between the first fiber film and the second fiber film to facilitate bonding. Specifically, the first fiber film and the second fiber film can be laminated by coating the other side of the first fiber substrate, the other side of the second fiber substrate, or both of these with a commonly known adhesive.

[0099] The lamination of the first fiber film and the second fiber film can be carried out at 50 to 120°C.

[0100] Through these processes, a packaging material in the form of a film having a laminated structure of a surface coating layer / first fiber layer / second fiber layer / sealing coating layer can be manufactured.

[0101] Thus, the present invention can produce packaging materials that exhibit improved physical properties compared to packaging materials made from a single fiber film by manufacturing packaging materials using different types of fiber films (e.g., paper film) that serve different purposes.

[0102] Specifically, conventional methods have attempted to manufacture packaging materials with high mechanical strength while possessing printability, waterproofing / stain resistance, and sealing properties using a single fiber film. However, this approach was limited by the physical property limitations of a single fiber film, making it difficult to produce packaging materials that satisfy all of the aforementioned performance requirements. In contrast, the present invention provides packaging materials that satisfy all of the aforementioned performance requirements by combining a first fiber film, which is intended to enhance printability and stain resistance / waterproofing, with a second fiber film, which is intended to enhance sealing properties and mechanical strength.

[0103] On the other hand, the method for manufacturing a packaging material according to one embodiment of the present invention may further include the step of forming a barrier layer inside the packaging material using a barrier film or a barrier coating liquid.

[0104] Specifically, a method for manufacturing a packaging material according to one embodiment of the present invention may include the step of laminating a barrier film between the first fiber film and the second fiber film.

[0105] The barrier film may include a biodegradable resin or a water-soluble resin that can enhance the gas barrier properties of the packaging material while ensuring recyclability and biodegradability. Specifically, the barrier film may include one or more substances selected from the group consisting of polyhydroxyalkanoate (PHA), polylactic acid (PLA), polyvinyl alcohol (PVOH), ethylene vinyl alcohol (EVOH), polybutylene adipate-co-terephthalate (PBAT), polybutylene succinate (PBS), polycaprolactone (PCL), thermoplastic starch (TPS), cellulose-derived substances, whey protein, soy protein, and wheat protein.

[0106] The lamination of the first fiber film, the barrier film, and the second fiber film can be carried out at 50 to 120°C.

[0107] Furthermore, the method for manufacturing a packaging material according to one embodiment of the present invention may further include the step of coating the other side of the first fiber film or the other side of the second fiber film with a barrier coating liquid.

[0108] The barrier coating liquid may contain a biodegradable resin or a water-soluble resin that can enhance the gas barrier properties of the packaging material while ensuring recyclability and biodegradability. Specifically, the barrier coating liquid may contain one or more selected from the group consisting of polyhydroxyalkanoates (PHA), polylactic acid (PLA), polyvinyl alcohol (PVOH), ethylene vinyl alcohol (EVOH), polybutylene adipate-co-terephthalate (PBAT), polybutylene succinate (PBS), polycaprolactone (PCL), thermoplastic starch (TPS), cellulose-derived substances, whey protein, soy protein, and wheat protein. In addition, the barrier coating liquid may further contain commonly known additives (e.g., crosslinking agents, emulsifiers, fillers, antioxidants, smoothing agents, defoaming agents, etc.) and solvents.

[0109] The coating of the barrier coating liquid can be carried out at a temperature of 80 to 150 degrees Celsius.

[0110] Furthermore, the method of coating with the barrier coating liquid is not particularly limited, and methods such as extrusion coating, spin coating, or spray coating can be used.

[0111] Through the process of forming these barrier layers, a packaging material in the form of a film having a laminated structure of a surface coating layer, a first fiber layer, a barrier layer, a second fiber layer, and a sealing coating layer can be manufactured.

[0112] The packaging material produced through the process described above can be used to package a variety of items as is, or it can be used for packaging after post-processing. Examples of such post-processing include adding air caps to enhance shock absorption, or molding the material to a required shape (e.g., extrusion molding, injection molding, compression molding, pressure molding, blowing or blow molding, thermoforming, etc.).

[0113] Embodiments of the Invention The present invention will be described more specifically below through examples. However, the scope of the present invention is not limited by these examples.

[0114] <Manufacturing of environmentally friendly multi-layer packaging materials> Example 1 Paper (basis weight: 60g / m 2 A first fiber film was manufactured by coating a white, high-quality paper with a water-based thermosetting acrylic resin coating solution and drying it at 100-150°C, thereby bonding the surface coating layer with the first fiber layer (first paper layer).

[0115] Paper (basis weight: 40g / m 2 , Density: 0.8~1.2kg / m 3 A second fiber film was produced by coating glassine paper with an aqueous thermoplastic acrylic resin coating solution and drying it at 100-150°C, thereby bonding the sealing coating layer and the second fiber layer (second paper layer).

[0116] The first fiber film and the second fiber film were arranged and laminated so that the first fiber layer and the second fiber layer faced each other. At this time, a urethane-based solvent-free adhesive was used between them so that the first fiber film and the second fiber film were bonded together through the lamination.

[0117] Through these processes, a packaging material was manufactured in which a surface coating layer (thickness: 10 μm), a first fiber layer (thickness: 68 μm), a second fiber layer (thickness: 40 μm), and a sealing coating layer (thickness: 18 μm) were laminated in that order.

[0118] Example 2 A PVOH film was placed between the first fiber film and the second fiber film manufactured as in Example 1 above, and the films were laminated to produce a packaging material in the following order: surface coating layer (thickness: 10 μm) / first fiber layer (thickness: 68 μm) / barrier layer (thickness: 20 μm) / second fiber layer (thickness: 40 μm) / sealing coating layer (thickness: 18 μm). At this time, a urethane-based solvent-free adhesive was used between each film so that each film was bonded together through the lamination.

[0119] Comparative Example 1 Paper (basis weight: 80g / m 2 A packaging material was manufactured by coating one side of white fine paper with a water-based thermosetting acrylic resin coating liquid and drying it at 100-150°C, and then coating the other side with a water-based thermoplastic acrylic resin coating liquid and drying it at 100-150°C, resulting in one side being water-resistant and the other side having sealing properties.

[0120] Experimental example The physical properties of the packaging materials produced in the examples and comparative examples were evaluated using the following methods, and the results are shown in Table 1 below.

[0121] 1. Cob size: Measured by adjusting the absorption time to 30 minutes based on the Tappi T 411 experimental method.

[0122] 2. Oxygen permeability: Measured using a Mocon OX-TRAN(R)2 / 22 oxygen permeability meter at 23±0.5℃.

[0123] 3. Moisture transmission: Measured using a Mocon Permatran-w(R)3 / 34 moisture permeability meter under conditions of 38±0.5℃ and 90±2% relative humidity.

[0124] 4. Sealing strength (thermal bonding strength): Measured using an Instron 3365 R 7300 universal tensile tester under the following conditions: grip spacing of 50 mm, speed of 100 mm / min, and sample width of 15 mm.

[0125] 5. Tensile Strength: After preparing specimens according to ASTM D882, they were cut to a length of 100 mm and a width of 15 mm, mounted with a distance of 50 mm between the chucks, and measured using an Instron 3365 R 7300 universal tensile tester.

[0126] [Table 1]

[0127] Referring to Table 1, it can be confirmed that Examples 1 and 2, which are packaging materials according to the present invention, have a low degree of bump size and high sealing strength and tensile strength. [Explanation of Symbols]

[0128] 10: Packaging material 11: Surface coating layer 12: First fiber layer 13: Second fiber layer 14: Sealing coating layer 15: Barrier layer 16: Adhesive layer

Claims

1. It includes a surface coating layer, a first fiber layer, a second fiber layer, and a sealing coating layer. The first fiber layer includes a primer layer formed on its surface. A multilayer packaging material wherein the primer layer contains one or more selected from the group consisting of polyvinyl alcohol (PVOH) and modified starch.

2. A multilayer packaging material comprising a surface coating layer, a first fiber layer, a second fiber layer, and a sealing coating layer, wherein the second fiber layer partially contains components derived from the sealing coating layer.

3. The multilayer packaging material according to claim 1 or 2, wherein the surface energy of the surface coating layer is 38 dyne / cm or more, and the sealing strength of the sealing coating layer is 1 kgf / 15 mm or more.

4. The multilayer packaging material according to claim 1 or 2, wherein the surface coating layer comprises one or more selected from the group consisting of aqueous thermosetting acrylic resin, aqueous latex, aqueous modified latex, aqueous urethane resin, and polyethylene emulsion.

5. The second fiber layer has a density of 0.8 kg / m³. ３ The multilayer packaging material according to claim 1 or 2.

6. The multilayer packaging material according to claim 1 or 2, wherein the sealing coating layer comprises one or more selected from the group consisting of aqueous thermoplastic acrylic resin, polyhydroxyalkanoate (PHA), and polyethylene emulsion.

7. The multilayer packaging material according to claim 1 or 2, further comprising a barrier layer formed between the first fiber layer and the second fiber layer.

8. The multilayer packaging material according to claim 7, wherein the barrier layer comprises a biodegradable resin or a water-soluble resin.

9. The multilayer packaging material according to claim 7, wherein the barrier layer contains one or more selected from the group consisting of polyhydroxyalkanoate (PHA), polylactic acid (PLA), polyvinyl alcohol (PVOH), ethylene vinyl alcohol (EVOH), polybutylene adipate-co-terephthalate (PBAT), polybutylene succinate (PBS), polycaprolactone (PCL), thermoplastic starch (TPS), cellulose-derived substances, whey protein, soy protein, and wheat protein.

10. Cobb sizing degree of 25 g / m ２ - A multilayer packaging material according to claim 1 or 2, wherein the length is 30 min or less.

11. Oxygen permeability of 100 cc / m³ ２ - The moisture permeability is less than or equal to 100 g / m². ２ - A multilayer packaging material according to claim 10, wherein the number of days is less than or equal to [number] days.

12. The multilayer packaging material according to claim 10, wherein the sealing strength is 1 kgf / 15 mm or more.

13. The multilayer packaging material according to claim 10, wherein the surface energy is 38 dyne / cm or more.

14. A step of manufacturing a first fiber film by coating one surface of a first fiber substrate with a surface coating liquid; A step of manufacturing a second fiber film by coating one surface of a second fiber substrate with a sealing coating liquid; and A method for producing a multilayer packaging material according to claim 1 or 2, comprising the step of laminating the first fiber film and the second fiber film such that the first fiber base material and the second fiber base material face each other.

15. A method for manufacturing a multilayer packaging material according to claim 14, comprising the step of arranging a barrier film between the first fiber film and the second fiber film and laminating them.

16. A method for producing a multilayer packaging material according to claim 14, further comprising the step of coating the other surface of the first fiber film or the other surface of the second fiber film with a barrier coating liquid.

Images