Environmentally friendly packaging materials and their manufacturing methods

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 a packaging material having a multi-layer structure, excellent printability, stain resistance / water resistance, sealing properties, and barrier properties against oxygen and / or moisture, which is easy to recycle and biodegrade, and is environmentally friendly, and a method for producing the same. [Background technology]

[0002] Generally, packaging materials used to package items such as food, medicines, cosmetics, and industrial products are composed 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] In this regard, conventionally, packaging materials have been manufactured by applying a polyethylene terephthalate (PET) film or a polypropylene (PP) film to the base layer, an aluminum foil or a nylon film to the barrier layer, and a low-density polyethylene (LDPE) film, a linear low-density polyethylene (LLDPE) film or a compact polypropylene (CPP) film to the inner layer.

[0004] However, these packaging materials are difficult to recycle. Because they are made of persistent materials, there are problems such as not being able to completely decompose naturally when landfilled, and depending on the type, it can take hundreds of years for them to decompose. In particular, they are hardly decomposed in soil or the ocean, causing serious problems such as air pollution and marine pollution.

[0005] In order to solve these problems, environmentally friendly packaging materials have been developed recently that combine easily degradable biodegradable materials (e.g., polylactic acid (PLA)) with highly recyclable paper instead of poorly degradable materials such as PET, nylon, and aluminum.

[0006] However, the biodegradable materials have low barrier properties against oxygen and moisture, and packaging materials made using them have limitations in exhibiting the barrier properties required for packaging of food, cosmetics, medicines, etc. Furthermore, packaging materials combining biodegradable materials and paper have the disadvantage that they lack sealing properties and the layer made of the biodegradable material and the paper layer peel off during use or processing. In addition, it is difficult to ensure printability for designs and stain resistance / water resistance.

[0007] Therefore, there is a need to develop packaging materials that are easily decomposed in soil and oceans, while also being highly recyclable and offering improved performance. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Korean Patent Publication No. 2012-0103158 Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention provides a packaging material that is highly recyclable, easily decomposes in soil and the ocean, and has excellent barrier properties against oxygen and / or moisture (gas barrier properties), printability, stain resistance / water resistance, sealing properties, etc.

[0010] In addition, the present invention provides a method for producing the packaging material, which can efficiently produce the packaging material. [Means for solving the problem]

[0011] In order to solve the above problems, according to one aspect of the present invention, there is provided a multi-layer packaging material including a surface coating layer, a first fiber layer, a second fiber layer, and a sealing coating layer.

[0012] In an embodiment, the surface coating layer may include at least one selected from the group consisting of water-based thermosetting acrylic resin, water-based latex, water-based modified latex, water-based urethane resin, and polyethylene emulsion.

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

[0014] In yet another embodiment, the second fibrous layer has a density of 0.8 kg / m 3 It may be more than that.

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

[0016] In yet another embodiment, the sealing coating layer may include at least one selected from the group consisting of water-based thermoplastic acrylic resin, polyhydroxyalkanoate (PHA), and polyethylene emulsion.

[0017] In yet another embodiment, the multi-layer packaging material may further include a barrier layer formed between the first fibrous layer and the second fibrous 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 comprise one or more selected from the group consisting of polyhydroxyalkanoates (PHAs), polylactic acids (PLAs), polyvinyl alcohols (PVOHs), ethylene vinyl alcohols (EVOHs), polybutylene-adipate-co-terephthalates (PBATs), polybutylene succinates (PBSs), polycaprolactones (PCLs), thermoplastic starches (TPSs), cellulose derived materials, whey proteins, soy proteins, and wheat proteins.

[0020] Meanwhile, according to another aspect of the present invention, a spunbonded fiber ... 2 ·Provide multi-layer packaging materials under 30 minutes.

[0021] In one embodiment, the multi-layer packaging material has an oxygen permeability of 100 cc / m 2 ·day or less, and moisture permeability is 100g / m 2 ·days or less is acceptable.

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

[0023] In yet another embodiment, the multi-layer packaging material has a surface energy of 38 dyne / cm or more.

[0024] On the other hand, according to one aspect of the present invention, there is provided a method for manufacturing a multilayer packaging material, comprising the steps of: coating one side of a first fiber substrate with a surface coating liquid to manufacture a first fiber film; coating one side of a second fiber substrate with a sealing coating liquid to manufacture a second fiber film; 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 method may include laminating a barrier film between the first fiber film and the second fiber film.

[0026] In another embodiment, the method may further include coating the other surface of the first fiber film or the other surface of the second fiber film with a barrier coating liquid. Effect of the Invention

[0027] The packaging material according to the present invention has a specific multi-layer structure in which two fiber layers are provided inside and a surface coating layer and a sealing coating layer are provided on the outside of the fiber layers, respectively, and therefore has excellent barrier properties against oxygen and / or moisture, printability, stain resistance / water resistance, sealing properties, etc.

[0028] In addition, the packaging material according to the present invention has a surface coating layer and a sealing coating layer made of a water-based resin material, and two fiber layers made of a paper material, so that the packaging material has high recyclability and is easily decomposed in soil and ocean.

[0029] In addition, the packaging material according to the present invention further includes a barrier layer made of a biodegradable or water-soluble resin material between the two fiber layers, and therefore has excellent barrier properties against oxygen and / or moisture as well as biodegradability.

[0030] In addition, the packaging material according to the present invention is manufactured by applying techniques such as lamination and extrusion coating, which are used in the manufacture of plastic films, and therefore has 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, medicines, cosmetics, industrial products, etc. [Brief description of the drawings]

[0032] [Figure 1] 1 is a cross-sectional view showing a packaging material according to an embodiment of the present invention. [Diagram 2] FIG. 4 is a cross-sectional view showing a packaging material according to another embodiment of the present invention. [Diagram 3]FIG. 4 is a cross-sectional view showing a packaging material according to still another embodiment of the present invention. [Figure 4] FIG. 4 is a cross-sectional view showing a packaging material according to still another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] The present invention will be described below with reference to examples. The present invention is not limited to the following disclosed contents, and may be modified in various forms without departing from the spirit and scope of the invention.

[0034] In the present specification, when a component is described as being formed above / below another component or being connected or joined to each other, it includes the case where these components are directly formed, connected or joined between them or indirectly formed, connected or joined through another component. It should be understood that the reference to the above / below of each component may change depending on the direction in which the object is observed.

[0035] As used herein, the term "comprising" is intended to embody certain features, regions, steps, processes, elements and / or components and does not exclude the presence or addition of other features, regions, steps, processes, elements and / or components, unless specifically stated to the contrary.

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

[0037] All numbers and expressions expressing quantities of components, reaction conditions, and the like described herein can be understood to be modified in all instances by the term "about," unless otherwise indicated.

[0038] The present invention relates to a packaging material having a specific multi-layer structure (e.g., including two or more fiber layers) and a method for manufacturing the packaging material by applying a process such as lamination or extrusion coating, which will be described in detail 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] Each layer will now be described in detail with reference to FIGS.

[0041] Surface Coating Layer The packaging material 10 according to an embodiment of the present invention includes a surface coating layer 11. The surface coating layer 11 serves to improve the printability (design), water resistance (waterproofness), and stain resistance of the packaging material 10.

[0042] The surface coating layer 11 can be formed into a film and can include a material having water-soluble properties while exhibiting the water resistance required for the packaging material 10. Specifically, the surface coating layer 11 can include one or more selected from the group consisting of an aqueous thermosetting acrylic resin, an aqueous latex, an aqueous modified latex, an aqueous urethane resin, and a polyethylene emulsion. The surface coating layer 11 can include the material having water-soluble properties to enhance the recyclability of the packaging material 10. In addition, the surface coating layer 11 can further include additives such as mineral oil and wax to ensure water resistance and antifouling properties.

[0043] The surface coating layer 11 may have a surface energy of 38 dyne / cm or more. Specifically, the surface coating layer 11 may 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, printing can be easily performed on the surface coating layer 11, and the printability (design) of the packaging material 10 can be improved.

[0044] In addition, the surface coating layer 11 may have antifouling / waterproof properties to improve the usability and processability of the packaging material 10. Specifically, the surface coating layer 11 may have a thickness of 30 g / m 2 The surface coating layer 11 may have a Cobb sizing degree of 30 min or less. More specifically, the surface coating layer 11 may have a Cobb sizing degree of 1 to 30 g / m 2 30min, 1~25g / m 2 30 min, 1-20 g / m 2 30min, 1~14g / m 2 30min or 1-10g / m 2 It can have a Cobb sizing degree of 30 min, which can significantly improve the waterproofness of the packaging material 10.

[0045] The thickness of the surface coating layer 11 may be 3 to 30 μm, 3 to 20 μm, 3 to 15 μm, 3 to 10 μm, or 5 to 10 μm. When the thickness of the surface coating layer 11 is within the above range, the water resistance, stain resistance, printability, etc. of the packaging material 10 are ensured, while preventing the packaging material 10 from becoming thicker than necessary, thereby improving productivity.

[0046] The surface coating layer 11 may be composed of a single layer, or may be composed of two or more layers (e.g., a laminated structure of a first surface coating layer / a second surface coating layer, or a laminated structure of a first surface coating layer / a second surface coating layer / a third surface coating layer, etc.) to enhance water resistance, etc.

[0047] First Fiber Layer The packaging material 10 according to an embodiment of the present invention includes a first fiber layer 12. A surface coating layer 11 may be formed on one side of the first fiber layer 12. The first fiber layer 12 serves to facilitate the formation of the surface coating layer 11 while ensuring the appearance 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 may be manufactured or selected according to the purpose of use. Since the first fiber layer 12 includes paper made from the pulp, the packaging material 10 according to the present invention has excellent biodegradability and recyclability compared to conventional packaging materials using synthetic resin base materials such as polyethylene terephthalate (PET) and polypropylene (PP).

[0049] Specifically, the first fiber layer 12 may include paper having excellent water resistance (e.g., paper sized with alkyl ketene dimer (AKD) or aluminum-rosin). When the first fiber layer 12 includes the paper having excellent water resistance, migration of a surface coating liquid for forming the surface coating layer 11 is prevented by the paper, and the surface coating layer 11 is more easily formed.

[0050] Meanwhile, 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 oxygen and / or moisture barrier properties of the packaging material 10 can be further improved, and the adhesive strength with the surface coating layer 11, the second fiber layer 13, or the barrier layer 15 described below can be increased.

[0051] The primer layer may include a commonly known anchor coating agent, specifically, the primer layer may include at least one selected from the group consisting of polyvinyl alcohol (PVOH) and modified starch.

[0052] Second Fiber Layer The packaging material 10 according to an embodiment of the present invention includes a second fiber layer 13. A sealing coating layer 14 may be formed on one side of the second fiber layer 13. The second fiber layer 13 functions to enhance the mechanical strength and smoothness of the packaging material 10 and to form 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. The paper may be at least one selected from the group consisting of white wood-free paper (imitation paper), beautiful color 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, tanto paper, fancy paper, white cardboard, and photographic paper. Since the second fiber layer 13 includes the paper, the packaging material 10 according to the present invention is more biodegradable and recyclable than conventional packaging materials using synthetic resin base materials such as polyethylene terephthalate (PET) and polypropylene (PP).

[0054] The second fiber layer 13 has a density of 0.8 kg / m 3 Specifically, the density of the second fiber layer 13 is 0.8 to 1.5 kg / m 3 , 0.9~1.5kg / m 3 , 1.0~1.5kg / m 3 , 1.0~1.3kg / m 3 , or 1.0 to 1.2 kg / m 3 When the density of the second fiber layer 13 is within the above range, the fibers in the second fiber layer 13 have a very high bonding strength, and the mechanical strength of the packaging material 10 can be significantly increased.

[0055] The second fiber layer 13 may have a ratio of softwood fiber of 20 to 100% of the total fiber in the second fiber layer 13. When the ratio of softwood fiber in the second fiber layer 13 is within the above range, the ratio of long fiber in the second fiber layer 13 increases, thereby increasing mechanical strength and density.

[0056] Meanwhile, the second fiber layer 13 may partially contain a component derived from the sealing coating layer 14. Specifically, the second fiber layer 13 may include a composite layer formed by partially impregnating with a sealing coating liquid for forming the sealing coating layer 14. For example, referring to FIG. 2, the second fiber layer 13 may include a paper layer 13a and a composite layer 13b in which the paper substrate and a component derived from the sealing coating layer 14 are combined. By including the composite layer 13b, the second fiber layer 13 may exhibit a significantly high bonding strength with the sealing coating layer 14.

[0057] Sealing Coating Layer The packaging material 10 according to an embodiment of the present invention includes a sealing coating layer 14. The sealing coating layer 14 is formed on one side of the second fiber layer 13, and serves to enhance the water resistance and sealing property of the packaging material 10.

[0058] The sealing coating layer 14 is strongly bonded to the second fiber layer 13, and can enhance the sealing property of the packaging material 10, and can include a water-dispersible thermoplastic resin (e.g., acrylic resin, polypropylene, etc.). Specifically, the sealing coating layer 14 can include a material having water-soluble or biodegradable properties while enhancing the sealing property of the packaging material 10. For example, the sealing coating layer 14 can include one or more selected from the group consisting of a water-soluble thermoplastic acrylic resin, polyhydroxyalkanoate (PHA), and polyethylene emulsion. The sealing coating layer 14 includes the water-soluble or biodegradable material, and thus the packaging material 10 can have excellent sealing property and can be improved in recyclability.

[0059] The sealing coating layer 14 may have a sealing strength (thermal adhesion strength) of 1 kgf / 15 mm or more to improve usability, processability, etc. of the packaging material 10. Specifically, the sealing coating layer 14 may 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 the sealing coating layer 14 may be 3 to 30 μm, 10 to 30 μm, 13 to 28 μm, 15 to 25 μm, or 17 to 25 μm. When the thickness of the sealing coating layer 14 is within the above range, the packaging material 10 is prevented from becoming thicker than necessary while ensuring the stain resistance, sealing property, etc. of the packaging material 10, thereby improving productivity.

[0061] The sealing coating layer 14 may be a single layer or may be composed of two or more layers (e.g., a laminate structure of a first sealing coating layer / a second sealing coating layer, or a laminate structure of a first sealing coating layer / a second sealing coating layer / a third sealing coating layer) to enhance sealing strength.

[0062] Barrier Layer The packaging material 10 according to an embodiment of the present invention may further include a barrier layer to enhance the barrier properties against oxygen and / or moisture.

[0063] 3, the barrier layer 15 may be formed between the first fiber layer 12 and the second fiber layer 13. The barrier layer 15 serves 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 ensure recyclability and biodegradability while improving the gas barrier properties of the packaging material 10. 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. When the thickness of the barrier layer 15 is within the above range, the gas barrier properties of the packaging material 10 can be improved while improving production efficiency and productivity.

[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 for bonding each layer.

[0067] 4(a), the adhesive layer 16 may be formed between the first fiber layer 12 and the second fiber layer 13. Also, referring to FIG. 4(b), the adhesive layer 16 may 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. These adhesive layers 16 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, processability, etc. of the packaging material 10.

[0068] The adhesive layer 16 may include an adhesive material that exhibits high adhesive strength without deteriorating the physical properties of the packaging material 10. Specifically, the adhesive layer 16 may include at least one selected from the group consisting of polyhydroxyalkanoate (PHA), polyvinyl alcohol (PVA), ethylene vinyl acetate (EVA), polyolefin-based 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. When the thickness of the adhesive layer 16 is within the above range, the processability, usability, etc. of the packaging material 10 can be improved.

[0070] Packaging material properties 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 / m 2 Specifically, the packaging material according to one embodiment of the present invention has a cob sizing degree of 1 to 30 g / m 2 30min, 1~25g / m 2 30 min, 1-20 g / m 2 30min, 1~14g / m 2 30min or 1-10g / m 2 When the Cobb sizing degree is within the above range, the packaging material according to the present invention exhibits high mechanical strength and excellent oxygen and / or moisture barrier properties.

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

[0072] formula 1

[0073] Cobb size degree = (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 / m 2 ·day or less, and moisture permeability is 100g / m 2 Specifically, the packaging material according to an embodiment of the present invention has an oxygen permeability of 0.1 to 100 cc / m at 23° C. and 0% RH. 2 Day, 0.1~50cc / m 2 Day, 0.1~10cc / m 2 Day, 0.1~5cc / m 2 day, or 0.1~1cc / m 2 The packaging material according to an embodiment of the present invention may have a moisture permeability of 0.1 to 100 g / m at 37.8° C. and 100% RH. 2 Day, 0.1~50g / m 2 Day, 0.1-10g / m 2 Day, 0.1-5g / m 2 day, or 0.1-1g / m 2 ·day is also acceptable.

[0075] The packaging material according to the present invention may have a sealing strength (thermal adhesive strength) of 1 kgf / 15 mm or more. Specifically, when the packaging material according to an embodiment of the present invention includes a sealing coating layer, the sealing strength of the sealing coating layer may be 1-5 kgf / 15 mm, 1.5-5 kgf / 15 mm, 2-5 kgf / 15 mm, 2.5-5 kgf / 15 mm, or 3-5 kgf / 15 mm. Since the sealing strength is within the above range, the packaging material according to the present invention has excellent bonding (adhesion) properties between each layer (minimizing interlayer peeling phenomenon), and thus the usability, processability, productivity, etc. of the packaging material can be improved.

[0076] The packaging material according to the present invention may have a surface energy (surface tension) of 38 dyne / cm or more. Specifically, the packaging material according to an embodiment of the present invention may 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 is within the above range, the packaging material according to the present invention has excellent printability (design). These surface energies can be measured with a surface tension measuring pen (e.g., a Dynepen).

[0077] The packaging material according to the present invention may have a tensile strength of 8 kgf or more as measured by a universal testing machine (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 to 18 kgf, 8 to 15 kgf, 10 to 15 kgf, or 12 to 15 kgf. By having the tensile strength 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 means the ratio of the packaging material decomposed to a standard material (e.g., cellulose) for a certain period of time, and can be calculated according to the following Equation 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 contained in the test material (CO2)B: Average cumulative amount of carbon dioxide generated from the inoculum source container ThCO2: Theoretical amount of carbon dioxide that can be generated from the test substance ThCO2=M TOT ×C TOT ×44 / 12 M TOT: Total dry solids (g) of the test material added to the compost at the start of the test C TOT : The percentage of organic carbon contained in the total dry solids of the test material (g / g) 44 / 12: Molecular weight of carbon dioxide and atomic weight of carbon

[0081] The packaging material according to the present invention includes a surface coating layer, a sealing coating layer, and a barrier layer that are biodegradable or water-soluble, and a first fiber layer and a second fiber layer that are relatively easily decomposed, so that the packaging material is easily decomposed in soil and ocean, and is environmentally friendly. The packaging material according to the present invention is also excellent in recyclability. The packaging material according to the present invention also has excellent gas barrier properties due to the barrier layer.

[0082] Therefore, the packaging material according to the present invention can be effectively used to package various products such as food, medicine, cosmetics, industrial products, etc. For example, the packaging material according to an embodiment of the present invention can be used as a pouch for retort food, a lead film for food containers, etc.

[0083] The packaging material according to the present invention may be manufactured to have a multi-layer structure by applying a process such as lamination, extrusion coating, etc., which will be described in detail below.

[0084] Manufacturing method for multi-layer packaging material In the method for manufacturing a packaging material according to an embodiment of the present invention, methods such as lamination and extrusion coating, which are used in manufacturing plastic films, are applied, and thus packaging materials having various laminated structures can be efficiently manufactured according to the purpose.

[0085] Specifically, the method for manufacturing a packaging material according to the present invention includes a step of coating one side of a first fiber substrate with a surface coating liquid to manufacture a first fiber film; a step of coating one side of a second fiber substrate with a sealing coating liquid to manufacture a second fiber film; and a step of laminating the first fiber film and the second fiber film so that the first fiber substrate and the second fiber substrate face each other, which will be described in detail as follows.

[0086] To form the above-mentioned surface coating layer and the first fiber layer, a surface coating liquid is coated on one side of the first fiber substrate to prepare a first fiber film.

[0087] The first fiber substrate is not particularly limited, and may include paper made from pulp, and may be prepared or selected according to the intended use.

[0088] The first fibrous substrate may be surface-treated with one or more types of primer selected from the group consisting of polyvinyl alcohol (PVOH) and modified starch.

[0089] The surface coating liquid may contain a material that exhibits the water resistance required for the packaging material and has water-soluble properties. Specifically, the surface coating liquid may contain at least one 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 contain additives such as mineral oil and wax, commonly known additives (e.g., polymerization initiator, crosslinking agent, emulsifier, filler, antioxidant, smoothing agent, defoamer, etc.), and solvent.

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

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

[0092] To form the sealing coating layer and the second fiber layer, a sealing coating liquid is coated on one side of the second fiber substrate to prepare a second fiber film.

[0093] The second fiber substrate may be paper made from mechanical pulp, semi-chemical pulp, chemical pulp, etc. Specifically, the paper may be at least one selected from the group consisting of white wood-free paper (imitation paper), beautiful color 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, tanto paper, fancy paper, white board, and photographic paper.

[0094] The second fiber base material has a density of 0.8 kg / m 3 or more (specifically 0.8 to 1.5 kg / m 3 , 0.9~1.5kg / m 3 , 1.0~1.5kg / m 3 , 1.0~1.3kg / m 3 , or 1.0 to 1.2 kg / m 3 ) may also be used.

[0095] The sealing coating liquid may include a thermoplastic resin (e.g., acrylic resin, polypropylene, etc.) that can be strongly bonded to the second fiber substrate to enhance the sealing property of the packaging material. Specifically, the sealing coating liquid may include a material having water-soluble or biodegradable properties. For example, the sealing coating liquid may include at least one selected from the group consisting of water-based thermoplastic acrylic resin, polyhydroxyalkanoate (PHA), and polyethylene emulsion. In addition, the sealing coating liquid may further include commonly known additives (e.g., polymerization initiator, crosslinking agent, emulsifier, filler, antioxidant, smoothing agent, defoamer, etc.) and a solvent.

[0096] The method of coating the sealing coating liquid on one side of the second fiber substrate is not particularly limited, and specifically, methods such as spray coating, spin coating, bar coating, dip coating, doctor blade, etc. may be used.

[0097] The applied sealing coating liquid is dried at 80 to 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 in a state where the first fiber substrate and the second fiber substrate face each other so that the first fiber layer and the second fiber layer can be formed inside the packaging material. Here, an adhesive may be coated between the first fiber film and the second fiber film so that they can be easily bonded. Specifically, the first fiber film and the second fiber film may be laminated by coating a commonly known adhesive on the other side of the first fiber substrate, the other side of the second fiber substrate, or both of them.

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

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

[0101] In this way, the present invention can produce a packaging material using different types of fiber films (e.g., paper films) having different purposes, thereby exhibiting improved physical properties compared to a packaging material produced using a single fiber film.

[0102] Specifically, in the past, attempts were made to manufacture a packaging material that had printability, waterproof / stain resistance, and sealing properties while also having high mechanical strength by using a single fiber film, but this was limited in terms of the physical properties of the single fiber film, and there were limitations in manufacturing a packaging material that satisfied all of the above performances. However, the present invention provides a packaging material that satisfies all of the above performances by combining a first fiber film that has the purpose of improving printability, stain resistance / waterproof properties, etc., with a second fiber film that has the purpose of improving sealing properties, mechanical strength, etc.

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

[0104] Specifically, the method for manufacturing a packaging material according to an embodiment of the present invention may include a step of disposing and 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 ensure recyclability and biodegradability while improving the gas barrier properties of the packaging material. Specifically, the barrier film may include at least one 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 may be performed at 50 to 120°C.

[0107] In addition, the method for manufacturing a packaging material according to an embodiment of the present invention may further include coating a barrier coating liquid on the other surface of the first fiber film or the other surface of the second fiber film.

[0108] The barrier coating liquid may contain a biodegradable resin or a water-soluble resin that can ensure recyclability and biodegradability while improving the gas barrier properties of the packaging material. Specifically, the barrier coating liquid may contain at least one 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. In addition, the barrier coating liquid may further contain commonly known additives (e.g., crosslinking agents, emulsifiers, fillers, antioxidants, smoothing agents, defoamers, etc.) and solvents.

[0109] The coating of the barrier coating solution may be performed at 80 to 150°C.

[0110] The method for coating the barrier coating liquid is not particularly limited, and specifically, methods such as extrusion coating, spin coating, and spray coating can be used.

[0111] Through the process of forming these barrier layers, a film-type packaging material 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 by the above process can be used as it is to package various items, or can be used for packaging after undergoing post-processing such as bonding with air caps to improve shock absorption, or molding into a desired shape (e.g., extrusion molding, injection molding, compression molding, pressure molding, blowing or blow molding, thermoforming, etc.).

[0113] Aspects of the invention The present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited to these examples.

[0114] <Manufacturing environmentally friendly multi-layer packaging materials> Example 1 Paper (basis weight: 60g / m 2 A water-based thermosetting acrylic resin coating solution was applied to a surface of a paper (white wood-free paper) and dried at 100 to 150°C to produce a first fiber film in which the surface coating layer and the first fiber layer (first paper layer) were bonded together.

[0115] Paper (basis weight: 40g / m 2 , Density: 0.8~1.2kg / m 3 A water-based thermoplastic acrylic resin coating solution was applied to a sheet of glassine paper, and the sheet was dried at 100 to 150°C to prepare a second fiber film in which the sealing coating layer and the second fiber layer (second paper layer) were bonded.

[0116] The first and second fiber films were arranged so that the first and second fiber layers faced each other and were laminated together, and a urethane-based solventless adhesive was used between the first and second fiber films to bond them together through the lamination.

[0117] Through these processes, a packaging material was produced 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 this order.

[0118] Example 2 A PVOH film was placed between the first and second fiber films prepared in Example 1, and the films were laminated to prepare a packaging material having a 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) laminated in this order. At this time, a urethane-based solventless adhesive was used between each film to bond each film through the lamination.

[0119] Comparative Example 1 Paper (basis weight: 80g / m 2 One side of a paper (paper, white wood-free paper) was coated with an aqueous thermosetting acrylic resin coating liquid and dried at 100 to 150°C, and the other side was coated with an aqueous thermoplastic acrylic resin coating liquid and dried at 100 to 150°C to produce a packaging material with water resistance on one side and sealability on the other side.

[0120] Experimental Example The physical properties of the packaging materials produced in the Examples and Comparative Examples were evaluated by the following methods, and the results are shown in Table 1 below.

[0121] 1. Cobb sizing degree: It was measured according to the Tappi T 411 experimental method, adjusting the absorption time to 30 minutes.

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

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

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

[0125] 5. Tensile strength: A test piece was prepared according to ASTM D882, cut to a length of 100 mm and a width of 15 mm, and attached so that the length between the chucks was 50 mm. The tensile strength was measured using an Instron 3365 R 7300 universal tensile tester.

[0126] [Table 1]

[0127] Referring to Table 1, it can be seen that Examples 1 and 2, which are packaging materials according to the present invention, have low Cobb 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. A multi-layer packaging material comprising a surface coating layer, a first fibrous layer, a second fibrous layer, and a sealing coating layer.

2. 2. The multi-layer packaging material according to claim 1, 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.

3. 2. The multi-layer packaging material according to claim 1, wherein the surface coating layer comprises at least one selected from the group consisting of an aqueous thermosetting acrylic resin, an aqueous latex, an aqueous modified latex, an aqueous urethane resin, and a polyethylene emulsion.

4. the first fiber layer includes a primer layer formed on a surface thereof, 2. The multi-layer packaging material according to claim 1, wherein the primer layer comprises at least one selected from the group consisting of polyvinyl alcohol (PVOH) and modified starch.

5. The second fiber layer has a density of 0.8 kg / m ３ The multi-layer packaging material according to claim 1 .

6. The multi-layer packaging material of claim 1 , wherein the second fibrous layer comprises in part a component derived from the sealing coating layer.

7. 2. The multi-layer packaging material of claim 1, wherein the sealing coating layer comprises one or more selected from the group consisting of water-based thermoplastic acrylic resins, polyhydroxyalkanoates (PHAs), and polyethylene emulsions.

8. The multi-layer packaging material of claim 1 further comprising a barrier layer formed between the first fibrous layer and the second fibrous layer.

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

10. 9. The multi-layer packaging material of claim 8, wherein the barrier layer comprises 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 materials, whey protein, soy protein, and wheat protein.

11. a first fibrous layer and a second fibrous layer; Cobb sizing degree is 25 g / m ２ - Multi-layer packaging material that is 30 min or less.

12. Oxygen permeability is 100cc / m ２ day or less, and the moisture permeability is 100 g / m ２ The multilayer packaging material according to claim 11, wherein the drying time is equal to or less than 1 day.

13. The multi-layer packaging material according to claim 11, having a sealing strength of 1 kgf / 15 mm or more.

14. The multi-layer packaging material according to claim 11, having a surface energy of 38 dyne / cm or more.

15. Coating one surface of a first fiber substrate with a surface coating liquid to produce a first fiber film; Coating one surface of a second fiber substrate with a sealing coating liquid to produce a second fiber film; and A method for manufacturing a multi-layer packaging material, comprising a step of laminating the first fiber film and the second fiber film so that the first fiber substrate and the second fiber substrate face each other.

16. 16. The method of claim 15, further comprising the step of laminating a barrier film between the first and second fibrous films.

17. The method for producing a multi-layer packaging material according to claim 15, 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.

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