Environmentally Friendly Laminate and Packaging Material Containing the Same

Abstract

The present disclosure relates to an environmentally friendly laminate and a packaging material containing the same. Specifically, the laminate according to one embodiment of the present invention includes a paper layer and a film layer, so that it has high recyclability, is easily decomposed in soil and the ocean, and is excellent in oxygen and / or moisture barrier properties, sealing properties, etc.

Description

Technical Field

[0001] The present disclosure relates to an environmentally friendly laminate that can be used as a packaging material in various fields because it is very easily biodegradable in the ocean and soil, is very environmentally friendly, and is excellent in oxygen and / or moisture barrier properties and sealing properties.

Background Art

[0002] Conventionally, in order to ensure the functionality of packaging materials, packaging materials have been manufactured by laminating multiple resin layers made of petrochemical synthetic resins. However, by using different petrochemical synthetic resins, the recyclability of the packaging material is reduced and the separation and disposal are restricted. Furthermore, in order to enhance the barrier properties against oxygen and / or moisture, an aluminum foil or a resin layer vapor-deposited with aluminum is applied, resulting in a problem that the separation and disposal of the packaging material are almost impossible.

[0003] In order to solve such problems, packaging materials manufactured using paper and biodegradable raw materials have been proposed. However, such packaging materials have a problem that the raw materials decompose only under specific conditions. Furthermore, in order to enhance the barrier properties against oxygen and / or moisture, the packaging material is manufactured by coating a metal substance instead of aluminum or introducing a barrier raw material such as EVOH, PVA, or PVDC. However, these are difficult to decompose in soil and the ocean and cannot be a fundamental measure for solving separation and disposal and marine pollution caused by plastics.

[0004] As a result, paper packaging materials in which paper and a biodegradable film are joined have been developed in order to enhance the recyclability and marine biodegradability of packaging materials. However, the currently developed paper packaging materials have a larger content of the biodegradable film than the content of paper, and the recyclability has not been improved much. Furthermore, if the biodegradable film is not coated to ensure the barrier properties against oxygen and moisture, there is a limit to its use as an industrial packaging material for foods, cosmetics, etc. that require long-term storage stability.

[0005] Therefore, there is a need to develop a packaging material with high recyclability, easy to decompose in soil and the ocean, and improved performance.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] The present disclosure aims to provide a laminate with high recyclability, easy to decompose in soil and the ocean, and excellent barrier properties (gas barrier properties) against oxygen and / or moisture, sealing properties, etc.

[0008] Furthermore, the present disclosure aims to provide a packaging material including the above laminate.

Means for Solving the Problems

[0009] To solve the above problems, according to one aspect of the present disclosure, there is provided a laminate including a paper layer and a film layer, wherein the paper layer has a biocarbon content of 85% or more and a tensile strength of 8 MPa or more, the film layer contains polyhydroxyalkanoate (PHA), has a thickness of 8 to 70 μm, and the polyhydroxyalkanoate (PHA) is a homopolymer containing repeating units derived from monomers selected from the group consisting of 3-hydroxypropionic acid (3HP), 4-hydroxybutyrate (4HB), 3-hydroxyvalerate (3HV), 5-hydroxyvalerate (5HV), 3-hydroxyhexanoate (3HH), 6-hydroxyhexanoate (6HH), and 3-hydroxyoctanoate (3HO), or a copolymer containing one or more repeating units derived from monomers selected from the group consisting of 3-hydroxybutyrate (3HB), 3-hydroxypropionic acid (3HP), 4-hydroxybutyrate (4HB), 3-hydroxyvalerate (3HV), 5-hydroxyvalerate (5HV), 3-hydroxyhexanoate (3HH), 6-hydroxyhexanoate (6HH), and 3-hydroxyoctanoate (3HO), and containing the at least one repeating unit in an amount of 0.1 to 50% by weight, and the thickness of the film layer is less than 75% of the total thickness of the laminate.

[0010] In one embodiment, the polyhydroxyalkanoate (PHA) is a copolymer containing a first repeating unit and a second repeating unit, and the first repeating unit and the second repeating unit are each derived from a monomer selected from the group consisting of 3-hydroxybutyrate (3HB), 3-hydroxypropionic acid (3HP), 4-hydroxybutyrate (4HB), 3-hydroxyvalerate (3HV), 5-hydroxyvalerate (5HV), 3-hydroxyhexanoate (3HH), 6-hydroxyhexanoate (6HH), and 3-hydroxyoctanoate (3HO), and the first repeating unit and the second repeating unit may be different from each other.

[0011] In another embodiment, the polyhydroxyalkanoate (PHA) may be a copolymer containing 0.1 to 50% by weight of the first repeating unit or the second repeating unit based on the total weight of the polyhydroxyalkanoate (PHA).

[0012] In yet another embodiment, the polyhydroxyalkanoate (PHA) may be a copolymer containing 50 to 99.9% by weight of the first repeating unit derived from 3-hydroxybutyrate (3HB); and 0.1 to 50% by weight of the second repeating unit derived from a monomer selected from the group consisting of 3-hydroxypropionic acid (3HP), 4-hydroxybutyrate (4HB), 3-hydroxyvalerate (3HV), 5-hydroxyvalerate (5HV), 3-hydroxyhexanoate (3HH), 6-hydroxyhexanoate (6HH), and 3-hydroxyoctanoate (3HO) based on the total weight of the polyhydroxyalkanoate (PHA).

[0013] In yet another embodiment, the film layer may have a biocarbon content of 40% or more.

[0014] In yet another embodiment, the film layer may have a tensile strength of 5 MPa or more and a seal strength of 0.5 kgf or more.

[0015] In yet another embodiment, the film layer may further contain one or more selected from the group consisting of polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), thermoplastic starch (TPS), polyvinyl alcohol (PVA), polycaprolactone (PCL), bio-derived polyethylene, and bio-derived polypropylene.

[0016] In yet another embodiment, the polyhydroxyalkanoate (PHA) may be a poly(3-hydroxybutyrate-co-4-hydroxybutyrate) copolymer.

[0017] In yet another embodiment, the polyhydroxyalkanoate (PHA) may have an average molecular weight of 30,000 to 1,000,000 g / mol.

[0018] In yet another embodiment, the paper layer has a tensile strength of 8 to 100 MPa, a tear strength of 20 to 600 gf, and a basis weight of 30 to 350 g / m 2 and may be such.

[0019] In yet another embodiment, the laminate may have a peel strength of 200 gf or more.

[0020] In yet another embodiment, the laminate may have a total biocarbon content of 25% or more.

[0021] In yet another embodiment, the laminate has an oxygen permeability of 1 to 1,200 cc / m 2 ·day and a water permeability of 1 to 150 g / m 2 ·day and may be such.

[0022] According to another aspect of the present disclosure, a packaging material including the above laminate is provided.

Advantages of the Invention

[0023] The laminate according to the present disclosure has a specific range of biocarbon content and includes a paper layer and a film layer with optimized physical properties (e.g., tensile strength, tear strength, etc.). Therefore, it has high recyclability, is easily decomposed in soil and the ocean, and has excellent barrier properties (gas barrier properties) and sealability against oxygen and / or moisture even without including a conventional barrier layer.

[0024] Therefore, the laminate according to the present disclosure can be advantageously applied not only as a disposable packaging material used to maintain the packaged state for a short period but also as a packaging material for foods, pharmaceuticals, cosmetics, industrial products, etc. used to maintain the packaged state for a long period.

Brief Description of the Drawings

[0025]

Figure 1

Figure 2

Mode for Carrying Out the Invention

[0026] Hereinafter, the present disclosure will be described by way of embodiments. Here, the present invention is not limited to the content disclosed below, and can be modified into various forms without changing the gist of the invention.

[0027] In this specification, the description that a certain component is formed, connected, or joined above or below another component includes all of directly forming, connecting, or joining between these components or indirectly via other components. It should be understood that the criteria for the terms above and below each component can vary depending on the direction of observing the object.

[0028] In this specification, the description of "including" is for specifying a specific characteristic, region, step, process, element, and / or component, and does not exclude the existence or addition of other characteristics, regions, steps, processes, elements, and / or components unless otherwise stated.

[0029] All numbers and expressions indicating the amounts of components, reaction conditions, etc. described in this specification can be understood to be modified by the term "about" in all cases unless otherwise stated.

[0030] The present disclosure relates to a laminate including a paper layer and a film layer having a specific range of biocarbon content and optimized physical properties, and a packaging material including the same, and will be specifically described as follows.

[0031] Laminate The laminate according to the present disclosure includes a paper layer and a film layer, and will be specifically described as follows with reference to FIG. 1.

[0032] Paper layer The laminate 10 according to an embodiment of the present disclosure includes a paper layer 11. The paper layer 11 serves as a base material for forming the film layer 12 and as a printing layer in the laminate 10 while ensuring the mechanical strength of the laminate 10.

[0033] The paper layer 11 may be formed from a paper base material (paper making) made from mechanical pulp, semi-chemical pulp, chemical pulp, or the like. Specifically, the paper base material may include one or more selected from the group consisting of coated paper (imitation paper), book paper, colored coated paper, blotting paper, medium paper, file paper, art paper, snow paper, snow white paper, single-sided art paper, royal art paper, NCR paper, Rezac paper, laid paper, CCP paper, kraft paper, manila ivory paper, royal ivory paper, tracing paper, tant paper, fancy paper, cotton paper, label paper, white cardboard, photographic paper, and cup paper.

[0034] The paper layer 11 may have a bio-carbon content (renewable carbon content (carbon ratio)) of 85% (85 pMC (percent Modern Carbon)) or more. Specifically, the paper layer 11 may have a bio-carbon content of 85 - 100%, 85 - 99%, 85 - 95%, or 90 - 95%. When the bio-carbon content of the paper layer 11 is within the above range, the carbon dioxide emissions in the laminate 10 can be minimized. Here, the bio-carbon content can mean the value measured according to ASTM D6866.

[0035] The paper layer 11 may have a tensile strength of 8 MPa or more. Specifically, the paper layer 11 may have a tensile strength of 8 - 100 MPa, 20 - 90 MPa, 30 - 80 MPa, 40 - 70 MPa, or 50 - 60 MPa. When the tensile strength of the paper layer 11 is within the above range, it will have the mechanical strength and stiffness required in the processing process, and the processability and manufacturing efficiency of the laminate 10 can be improved. Here, the tensile strength can mean the value measured according to ASTM D882.

[0036] The paper layer 11 may have a tear strength of 20 to 600 gf. Specifically, the paper layer 11 may have a tear strength of 50 to 600 gf, 100 to 450 gf, 150 to 300 gf, 180 to 280 gf, or 200 to 250 gf. When the tear strength of the paper layer 11 is within the above range, it is possible to prevent the paper layer 11 from being torn or the cutting property from deteriorating during the processing of the laminate 10. Furthermore, at the time of opening the packaging material obtained from the laminate 10, it is possible to easily open the packaging material without tools. Here, the tear strength can mean a value measured according to TAPPI method 414 om-98.

[0037] The paper layer 11 may have a basis weight of 30 to 350 g / m 2 Specifically, the paper layer 11 may have a basis weight of 50 to 330 g / m 2 100 to 320 g / m 2 150 to 310 g / m 2 200 to 300 g / m 2 or 250 to 290 g / m 2 When the basis weight of the paper layer 11 is within the above range, the mechanical strength of the laminate 10 can be ensured.

[0038] The paper layer 11 may have a density of 0.6 to 1.2 g / cm 3 Specifically, the paper layer 11 may have a density of 0.7 to 1.2 g / cm 3 0.8 to 1.2 g / cm 3 or 0.9 to 1.1 g / cm 3 It may be.

[0039] The paper layer 11 can account for 50% by weight or more of the total weight of the laminate 10. Specifically, the content of the paper layer 11 may be 50 to 95% by weight, 55 to 95% by weight, 55 to 85% by weight, 60 to 80% by weight, or 65 to 75% by weight based on the total weight of the laminate 10. When the content of the paper layer 11 is within the above range, the laminate 10 can be separated and disposed of as paper, and the laminate 10 has excellent recyclability.

[0040] Note that the thickness of the paper layer 11 is 50% or more of the total thickness of the laminate 10, specifically, it may be 60% or more, 70% or more, 80% or more, or 90% or more (for example, 30 - 99%, 40 - 99%, 50 - 97%, 60 - 95%, or 70 - 93%). More specifically, the thickness of the paper layer 11 may be 25 - 500 μm, 40 - 450 μm, 50 - 400 μm, 80 - 380 μm, or 100 - 360 μm.

[0041] On the other hand, the paper layer 11 may optionally include a functional coating layer. Specifically, when higher barrier properties, heat insulation properties, high strength properties, etc. of the laminate 10 are required, on one or both sides of the paper layer 11, a functional coating layer formed from a coating composition containing one or more selected from the group consisting of graphene oxide, clay, montmorillonite, cyclodextrin, nano cellulose, aluminum, cellulose, silicon oxide (SiO X), and aluminum oxide (Al 2 O 3) may be further formed.

[0042] Furthermore, in order to enhance the bonding property with the film layer 12 and the gas barrier property of the laminate 10, etc., the paper layer 11 may further include a primer composition containing a water-soluble resin such as polyvinyl alcohol (PVOH); or a primer layer formed from a composition containing one or more of ethylene vinyl acetate - based resins, polyurethane - based resins, and acrylic - based resins.

[0043] Film layer The laminate 10 according to an embodiment of the present disclosure includes a film layer 12. The film layer 12 serves to enhance the gas barrier property, sealing property, biodegradability, etc. of the laminate 10.

[0044] The film layer 12 may contain polyhydroxyalkanoate (PHA). Specifically, the film layer 12 may consist of only polyhydroxyalkanoate (PHA), or may further contain a biodegradable resin in addition to polyhydroxyalkanoate (PHA). Specifically, the biodegradable resin may be at least one selected from the group consisting of polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), thermoplastic starch (TPS), polyvinyl alcohol (PVA), and polycaprolactone (PCL). Since the film layer 12 contains PHA and selectively further contains a biodegradable resin, it is easily decomposed by microorganisms, and thus the laminate 10 has excellent biodegradability in soil and the ocean. In particular, the film layer 12 can exhibit a fast biodegradation rate by essentially containing PHA that is more rapidly decomposed by microorganisms.

[0045] Furthermore, when attempting to achieve the goal of reducing carbon dioxide emissions while realizing mechanical properties along with biodegradability, the film layer 12 may further contain at least one of bio-derived polyethylene (Bio-PE) and bio-derived polypropylene (Bio-PP) in addition to polyhydroxyalkanoate (PHA).

[0046] Specifically, the film layer 12 may contain polyhydroxyalkanoate (PHA) and polylactic acid (PLA). At this time, the weight ratio of polyhydroxyalkanoate (PHA) to polylactic acid (PLA) contained in the film layer 12 may be 1:9 to 9:1, specifically, 2:8 to 8:2, 2.5:7.5 to 7.5:2.5, 3:7 to 7:3, 3.5:6.5 to 6.5:3.5, or 4:6 to 6:4. By the weight ratio being within the above range, the biodegradability of the laminate 10 can be enhanced while ensuring the seal strength and tensile strength of the film layer 12 at required levels.

[0047] The polyhydroxyalkanoate (PHA) contained in the film layer 12 may be produced (synthesized) through a known method using microorganisms, and may be a polyhydroxyalkanoate (PHA) in which the content of repeating units derived from monomers is controlled within a specific range. Specifically, the polyhydroxyalkanoate (PHA) may be a homopolymer obtained using one type of monomer as a reactant, or a copolymer obtained using one or more types of monomers as reactants.

[0048] More specifically, the polyhydroxyalkanoate (PHA) is a homopolymer containing repeating units derived from monomers selected from the group consisting of 3-hydroxypropionic acid (3HP), 4-hydroxybutyrate (4HB), 3-hydroxyvalerate (3HV), 5-hydroxyvalerate (5HV), 3-hydroxyhexanoate (3HH), 6-hydroxyhexanoate (6HH), and 3-hydroxyoctanoate (3HO), or a copolymer containing one or more repeating units (A) derived from monomers selected from the group consisting of 3-hydroxybutyrate (3HB), 3-hydroxypropionic acid (3HP), 4-hydroxybutyrate (4HB), 3-hydroxyvalerate (3HV), 5-hydroxyvalerate (5HV), 3-hydroxyhexanoate (3HH), 6-hydroxyhexanoate (6HH), and 3-hydroxyoctanoate (3HO).

[0049] When the polyhydroxyalkanoate (PHA) is a copolymer containing the repeating unit (A), the content of the repeating unit (A) may be 0.1 to 50% by weight (specifically, 2 to 45% by weight, 4 to 43% by weight, 6 to 40% by weight, or 8 to 35% by weight) based on the total weight of the polyhydroxyalkanoate (PHA). When the content of the repeating unit (A) is within the above range, melt extrusion coating and film processing for melting the polymer resin by heat are possible. That is, when the content of the repeating unit (A) exceeds 50% by weight, the melt strength of the melted resin (PHA resin) is low, and it may be difficult to improve the processing speed or to form a laminate (laminated film). Also, when the content of the repeating unit (A) is less than 0.1% by weight, the crystallinity is too high, and it may be difficult to realize the mechanical properties required for the packaging material.

[0050] Specifically, the polyhydroxyalkanoate (PHA) may be a copolymer containing a first repeating unit (B) derived from a monomer selected from the group consisting of 3-hydroxybutyrate (3HB), 3-hydroxypropionic acid (3HP), 4-hydroxybutyrate (4HB), 3-hydroxyvalerate (3HV), 5-hydroxyvalerate (5HV), 3-hydroxyhexanoate (3HH), 6-hydroxyhexanoate (6HH), and 3-hydroxyoctanoate (3HO); and a second repeating unit (C) derived from a monomer selected from the group consisting of 3-hydroxybutyrate (3HB), 3-hydroxypropionic acid (3HP), 4-hydroxybutyrate (4HB), 3-hydroxyvalerate (3HV), 5-hydroxyvalerate (5HV), 3-hydroxyhexanoate (3HH), 6-hydroxyhexanoate (6HH), and 3-hydroxyoctanoate (3HO), wherein the first repeating unit (B) and the second repeating unit (C) are different from each other.

[0051] When the polyhydroxyalkanoate (PHA) is a copolymer containing a first repeating unit (B) and a second repeating unit (C), the contents of these repeating units are not particularly limited. However, based on the total weight of the polyhydroxyalkanoate (PHA), the content of the first repeating unit (B) or the second repeating unit (C) may be 0.1 to 50% by weight (specifically, 2 to 45% by weight, 4 to 43% by weight, 6 to 40% by weight, or 8 to 35% by weight).

[0052] More specifically, the polyhydroxyalkanoate (PHA) may be a copolymer containing a first repeating unit (D) derived from 3-hydroxybutyrate (3HB); and a second repeating unit (E) derived from a monomer (comonomer) selected from the group consisting of 3-hydroxypropionic acid (3HP), 4-hydroxybutyrate (4HB), 3-hydroxyvalerate (3HV), 5-hydroxyvalerate (5HV), 3-hydroxyhexanoate (3HH), 6-hydroxyhexanoate (6HH), and 3-hydroxyoctanoate (3HO).

[0053] When the polyhydroxyalkanoate (PHA) is a copolymer containing a first repeating unit (D) and a second repeating unit (E), the contents of these repeating units are not particularly limited. However, based on the total weight of the polyhydroxyalkanoate (PHA), the content of the second repeating unit (E) may be 0.1 to 50% by weight, and thus the content of the first repeating unit (D) may be 50 to 99.9% by weight. By the contents of the first repeating unit (D) and the second repeating unit (E) being within the above ranges respectively, it is possible to enhance the moldability into a laminate while ensuring the mechanical properties required for the laminate as a packaging material. Specifically, the content of the first repeating unit (D) may be 55 to 98% by weight, 57 to 96% by weight, 60 to 94% by weight, or 65 to 92% by weight based on the total weight of the polyhydroxyalkanoate (PHA). Further, the content of the second repeating unit (E) may be 2 to 45% by weight, 4 to 43% by weight, 6 to 40% by weight, or 8 to 35% by weight based on the total weight of the polyhydroxyalkanoate (PHA).

[0054] As an example, the polyhydroxyalkanoate (PHA) may be a poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (Poly(3HB)-co-(4HB)) copolymer. As another example, the polyhydroxyalkanoate (PHA) may be a poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (Poly(3HB)-co-(3HV)) copolymer.

[0055] The polyhydroxyalkanoate (PHA) may have an average molecular weight of 30,000 to 1,000,000 g / mol, specifically 80,000 to 900,000 g / mol, 150,000 to 850,000 g / mol, or 250,000 to 750,000 g / mol. When the average molecular weight of the polyhydroxyalkanoate (PHA) is less than 30,000 g / mol, it may be difficult to achieve the seal strength and tensile strength required for processing into a laminate (laminated film) due to the low molecular weight, or it may be difficult to use as a packaging material due to a high decomposition rate. Also, when the average molecular weight of the polyhydroxyalkanoate (PHA) exceeds 1,000,000 g / mol, the viscosity of the molten resin (PHA resin) may be too high, making processing with an extruder difficult.

[0056] Furthermore, the polyhydroxyalkanoate (PHA) may have a melt flow index (Melt Flow Index, MFI) measured at 165°C and 5 kg of 0.1 to 40 g / 10 min, specifically 0.5 to 25 g / 10 min, 1 to 15 g / 10 min, or 2 to 10 g / 10 min. When the melt index of the polyhydroxyalkanoate (PHA) is less than 0.1 g / 10 min, the viscosity of the molten resin may be too high, making extrusion coating difficult, or the neck-in may be too large, reducing workability. Also, when the melt index of the polyhydroxyalkanoate (PHA) exceeds 40 g / 10 min, the melt strength of the molten resin may be too low, making processing into a laminate (laminated film) difficult.

[0057] The film layer 12 containing polyhydroxyalkanoate (PHA) may further contain a synthetic resin if necessary. Specifically, when high barrier properties of the laminate 10 are required, the film layer 12 may further contain one or more synthetic resins such as ethylene vinyl alcohol (EVOH), polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), and the like.

[0058] On the other hand, the film layer 12 may have a bio-carbon content (renewable carbon content (carbon ratio)) of 40% (40 pMC (percent Modern Carbon)) or more. Specifically, the film layer 12 may have a bio-carbon content of 40 to 100%, 50 to 95%, 60 to 90%, or 70 to 85%. By the bio-carbon content of the film layer 12 being within the above range, the carbon dioxide emissions in the laminate 10 can be minimized. Here, the bio-carbon content can mean a value measured according to ASTM D6866.

[0059] The film layer 12 may have a tensile strength of 5 MPa or more. Specifically, the film layer 12 may have a tensile strength of 5 to 120 MPa, 10 to 100 MPa, 15 to 80 MPa, 20 to 70 MPa, or 25 to 60 MPa. By the tensile strength of the film layer 12 being within the above range, it will have the mechanical strength and stiffness necessary in the processing step, and the processability and manufacturing efficiency of the laminate 10 can be improved. Here, the tensile strength can mean a value measured according to ASTM D882.

[0060] The film layer 12 may have a seal strength of 0.5 kgf or more, 0.6 kgf or more, 0.7 kgf or more, 0.8 kgf or more, 0.9 kgf or more, 1.0 kgf or more, 1.1 kgf or more, or 1.2 kgf or more. Specifically, the film layer 12 may have a seal strength of 0.6 to 5 kgf, 0.6 to 3 kgf, 0.7 to 2.5 kgf, 0.7 to 2 kgf, or 0.8 to 1.5 kgf. When the seal strength of the film layer 12 is within the above range, the sealability of the laminate 10 is ensured, and the laminate 10 can be used as a packaging material not only for short-term but also for long-term packaging. Here, the seal strength can mean a value measured according to ASTM D882.

[0061] The film layer 12 can account for less than 50% by weight of the total weight of the laminate 10. Specifically, the content of the film layer 12 may be 3 to 49.9% by weight, 5 to 45% by weight, 8 to 40% by weight, 15 to 45% by weight, or 10 to 35% by weight based on the total weight of the laminate 10. When the content of the film layer 12 is within the above range, the gas barrier property, sealability, etc. of the laminate 10 are ensured while being excellent in recyclability.

[0062] Also, the thickness of the film layer 12 is less than 75% of the total thickness of the laminate 10, specifically 70% or less, 65% or less, 60% or less, 50% or less, 40% or less, or 30% or less (for example, 1 to 70%, 1 to 60%, 3 to 50%, 5 to 40%, or 7 to 30%). Specifically, the thickness of the film layer 12 may be 8 to 70 μm, 10 to 70 μm, 12 to 55 μm, 20 to 50 μm, or 25 to 45 μm. When the thickness of the film layer 12 is within the above range, it is excellent in recyclability together with the sealability and gas barrier property of the laminate 10.

[0063] The film layer 12 may further include a functional coating layer as needed. Specifically, when higher barrier properties, heat insulation properties, high strength properties, etc. of the laminate 10 are required, a functional coating layer formed from a coating composition containing one or more selected from the group consisting of aluminum (Al), graphene oxide, clay, montmorillonite, cyclodextrin, nano cellulose, cellulose, silicon oxide (SiO X ) and aluminum oxide (Al 2 O 3 ) may be further formed on one or both surfaces of the film layer 12.

[0064] On the other hand, the laminate 10 according to an embodiment of the present disclosure can further include an adhesive layer 13 depending on the manufacturing method, and this will be described as follows with reference to FIG. 2.

[0065] Adhesive layer The laminate 10 according to an embodiment of the present disclosure can further include an adhesive layer 13 that bonds the paper layer 11 and the film layer 12. Specifically, the adhesive layer 13 is formed between the paper layer 11 and the film layer 12, strongly bonds the paper layer 11 and the film layer 12 to each other, and plays a role in enhancing the processability, usability, etc. of the laminate 10.

[0066] The adhesive layer 13 can include an adhesive substance that can exhibit a high bonding force without degrading the physical properties of the laminate 10. Specifically, the adhesive layer 13 can include one or more adhesive substances selected from the group consisting of polyvinyl alcohol (PVA), ethylene vinyl acetate (EVA) resin, acrylic resin, urethane resin, polyolefin resin, polybutylene succinate (PBS), polybutylene adipate terephthalate (PBAT), and polylactic acid (PLA).

[0067] The adhesive layer 13 may have a thickness of 0.5 to 25 μm, 0.6 to 15 μm, or 0.7 to 8 μm. By having the thickness of the adhesive layer 13 within the above range, the processability, usability, etc. of the laminate 10 can be enhanced.

[0068] The laminate 10 according to an embodiment of the present disclosure includes the paper layer 11 and the film layer 12 whose physical properties are optimized as described above, and thus can have a tensile strength of 15 to 150 MPa, 20 to 130 MPa, or 30 to 80 MPa. By having the tensile strength of the laminate 10 within the above range, the laminate 10 can exhibit improved processability.

[0069] The laminate 10 according to an embodiment of the present disclosure may have a seal strength of 0.8 to 10 kgf, 1 to 7 kgf, or 1.1 to 5 kgf. By having the seal strength of the laminate 10 within the above range, the laminate 10 can be advantageously used as a packaging material in various fields.

[0070] The laminate 10 according to an embodiment of the present disclosure may have a peel strength (bonding strength between the paper layer 11 and the film layer 12) of 80 gf or more, 90 gf or more, 100 gf or more, 150 gf or more, or 200 gf or more (specifically 100 to 2,000 gf, 300 to 1,000 gf, or 400 to 800 gf). By having the peel strength of the laminate 10 within the above range, the laminate 10 can exhibit improved processability. Further, when the adhesive force between the paper layer 11 and the film layer 12 is high and the paper layer 11 is separated between layers and it is impossible to measure the peel strength, it can have the most excellent processability.

[0071] The laminate 10 according to an embodiment of the present disclosure has an oxygen permeability of 1 to 1,200 cc / m 2 ·day, specifically 1 to 950 cc / m 2 ·day, 1 to 500 cc / m 2 ·day, or 1 to 300 cc / m 2 ·day. Further, the laminate 10 according to an embodiment of the present disclosure has a water permeability of 1 to 150 g / m 2 ·day, specifically 1 to 80 g / m 2· per day, 1 to 50 g / m 2 · per day, or 1 to 15 g / m 2 · per day may be sufficient. Since the oxygen permeability and water vapor permeability of the laminate 10 are within the above ranges, respectively, it has excellent gas barrier properties and can be advantageously used as a packaging material in various fields.

[0072] In particular, the laminate 10 according to an embodiment of the present disclosure does not include a barrier layer containing a metal substance or a barrier raw material such as EVOH, PVA, PVDC, etc., but includes a paper layer 11 and a film layer 12 with optimized physical properties and composition, thereby having excellent gas barrier properties for blocking oxygen and / or moisture.

[0073] The laminate 10 according to an embodiment of the present disclosure can have a total bio-carbon content (renewable carbon content (carbon ratio)) of 25% (25 pMC (percent Modern Carbon)) or more. Specifically, the laminate 10 may have a total bio-carbon content of 25 to 100%, 35 to 100%, 50 to 100%, 70 to 100%, or 90 to 100%. Since the total bio-carbon content of the laminate 10 is within the above range, the carbon dioxide emissions in the laminate are minimized, and it can be suitably used as a material for packaging containers or cardboard boxes that meet the required carbon emission reduction both domestically and internationally. Here, the bio-carbon content can mean a value measured according to ASTM D6866.

[0074] The laminate 10 according to an embodiment of the present disclosure may have a thickness of 30 to 600 μm, 40 to 500 μm, 50 to 400 μm, or 80 to 300 μm.

[0075] The laminate 10 according to an embodiment of the present disclosure includes a paper layer 11 and a film layer 12 with optimized physical properties, and thus can have tensile strength, seal strength, peel strength, etc., which are advantageously used as a packaging material for packaging articles in various fields. It also includes a separately disposable paper layer 11 and a film layer 12 with excellent biodegradability in soil and the ocean, and has excellent recyclability and environmental friendliness due to a total bio-carbon content of 25% or more.

[0076] The method for manufacturing the laminate 10 according to an embodiment of the present disclosure is not particularly limited, but it can be manufactured through resin melt coating such as extrusion coating or hot melt coating of a resin composition for forming a film layer (biodegradable resin composition) on the paper base material, or through the process of laminating a film using an adhesive.

[0077] The resin composition for forming the film layer essentially contains polyhydroxyalkanoate (PHA), and the coating amount is 8 - 70 g / m 2 , 15 - 70 g / m 2 , or 25 - 60 g / m 2 and may be sufficient. By having the coating amount within the above range, a film layer 12 that satisfies the required gas barrier property, sealability, recyclability, etc. can be formed.

[0078] Also, when extrusion coating the resin composition for forming the film layer, the appropriate processing temperature of the extruder may be 140 - 240°C, 150 - 220°C, or 160 - 210°C. By having the processing temperature of the extruder within the above range, the film layer 12 can be smoothly formed while preventing the decomposition of polyhydroxyalkanoate (PHA) contained in the resin composition for forming the film layer.

[0079] Packaging material The present disclosure provides a packaging material including the laminate described above. Specifically, the packaging material according to an embodiment of the present disclosure may be the laminate itself described above, or may be the one obtained by adding various functional layers to the laminate described above and subjecting it to post-processing.

[0080] The packaging material according to an embodiment of the present disclosure may further include a surface coating layer as the functional layer to enhance the printability, stain resistance, water resistance, etc. of the packaging material. The surface coating layer may include a substance having water-soluble properties while exhibiting water resistance. As an example, the surface coating layer may include one or more selected from the group consisting of a thermosetting acrylic resin, a urethane resin, and polyhydroxyalkanoate (PHA).

[0081] By including the surface coating layer and the above-described laminate, the packaging material according to an embodiment of the present disclosure can have a structure of surface coating layer / paper layer / film layer, and an adhesive layer or a primer layer can exist between the paper layer and the film layer.

[0082] The packaging material according to an embodiment of the present disclosure can be used by itself to package various articles, or can be used to package after undergoing post-processing. Examples of post-processing include a step of attaching an air cap or a step of molding according to a required shape (e.g., extrusion molding, injection molding, compression molding, pneumatic molding, blow molding, thermoforming, etc.) to enhance impact absorbency.

[0083] The packaging material according to an embodiment of the present disclosure includes a laminate including a paper layer and a film layer as described above, and thus is excellent not only in recyclability and biodegradability but also in seal strength, peel strength, gas barrier properties, etc., and can be advantageously used to package various articles such as foods, pharmaceuticals, cosmetics, industrial products (industrial goods), etc. that require not only short-term sealability but also long-term sealability.

[0084] Specifically, the packaging material according to an embodiment of the present disclosure can be used for food packaging materials such as coffee, cup rice, dried foods, retorts, etc.; mask packaging materials; cosmetic packaging materials; pharmaceutical packaging materials; or paper pack packaging materials such as milk cartons. As an example, the packaging material according to an embodiment of the present disclosure can have forms such as a paper container, a two-sided pouch, a three-sided pouch, an M-sided pouch, a box pouch (flat-bottom pouch), a stick-type pouch, etc.

Example

[0085] Hereinafter, the present disclosure will be described more specifically through examples. However, the scope of the present disclosure is not limited by these examples.

[0086] <Manufacture of laminate> Example 1 On a paper substrate with a bio-carbon content of 95% or more (95 pMC or more), a tensile strength of 50 MPa, a tear strength of 200 gf, and a basis weight of 280 g / m 2 (thickness: 350 ± 15 μm), a resin composition for forming a film layer containing polyhydroxyalkanoate (CJ CheilJedang, PHA (Poly(3HB)-co-(4HB)) containing 28% by weight of 4HB repeating units and polylactic acid (NatureWorks PLA) was extrusion-coated (extruder temperature 200 °C or lower) to form a film layer with a bio-carbon content of 98% or more (98 pMC or more), a tensile strength of 25 MPa, and a seal strength of 0.6 kgf (thickness: 40 μm). Through such a process, a laminate with a total bio-carbon content of 96% or more (96 pMC or more) was manufactured. Here, the tensile strength and seal strength of the paper substrate and the film layer were measured using an Instron 34SC-1 universal material testing machine.

[0087] Examples 2 to 4 A laminate was manufactured in the same manner as in Example 1, except that the physical properties and composition of the paper substrate and the film layer were adjusted as shown in Table 1.

[0088] Comparative Examples 1 to 6 A laminate was manufactured in the same manner as in Example 1, except that the physical properties and composition of the paper substrate and the film layer were adjusted as shown in Table 2. At this time, as PHA in the film layer of Comparative Example 1, poly(3-hydroxybutyrate) (Poly(3HB)) was applied.

[0089]

Table 1

[0090]

Table 2

[0091] <Test Example> Test Example 1. Processability of Packaging Material To confirm whether the resin composition for forming a film layer (biodegradable resin) can be processed as a packaging material, it was evaluated whether a film could be formed by extrusion, and whether printing, slitting, and bag-making of the laminate were possible. Specifically, in the case of film formation by extrusion, the film layer forming possibility of the resin composition, the gel value of the film layer, and the thickness forming possibility that can be used as a packaging material were evaluated. In the case of the laminate, the presence or absence of breakage of the base fabric of the laminate and the presence or absence of defects due to shrinkage or cut defects were evaluated when the printing, slitting, and bag-making processes were in progress.

[0092] When the evaluation result was qualified, it was evaluated as ○, and when it was unqualified due to physical properties, it was evaluated as × and shown in Table 3.

[0093] Test Example 2. Seal Strength The seal strength of the laminate was measured using an Instron 34SC-1 universal material testing machine with a sample width (Width) of 15 mm, a measurement length of 30 mm, and a measurement speed of 200 mm / min.

[0094] When the measured seal strength was 0.8 kgf or more, it was evaluated as ○, and when it was less than 0.8 kgf, it was evaluated as × and shown in Table 3.

[0095] Test Example 3. Peel Strength The peel strength between the paper layer and the film layer of the laminate was measured using an Instron 34SC-1 universal material testing machine with a sample width (Width) of 15 mm, a measurement length of 30 mm, and a measurement speed of 200 mm / min.

[0096] When the measured peel strength is 200 gf or more, or when the adhesive strength between the paper layer and the film layer is strong and the paper layer is delaminated and the peel strength cannot be measured, it is evaluated as ○, and when it is less than 200 gf, it is evaluated as × and shown in Table 3.

[0097] Test Example 4. Gas barrier property The water vapor transmission rate (MVTR) of the laminate was measured using a Mocon Permatran-w3 / 33 water vapor permeability meter under the conditions of 38 ± 0.5 °C and a relative humidity of 90 ± 2%. Also, the oxygen transmission rate (OTR) of the laminate was measured using a Mocon OX2-TRAN2 / 12 oxygen transmission rate measuring machine under the condition of 23 ± 0.5 °C.

[0098] When the measured oxygen transmission rate is 1,200 cc / m 2 · per day or less, and the water vapor transmission rate is 150 g / m 2 · per day or less, it is evaluated as ○, and when the oxygen transmission rate is 1,200 cc / m 2 · more than per day, and the water vapor transmission rate is 150 g / m 2 · more than per day, it is evaluated as × and shown in Table 3.

[0099]

Table 3

[0100] Referring to Table 3, the laminates of Examples 1 to 4 according to the present disclosure have a highly recyclable paper layer and a biodegradable film layer (excluding components such as petrochemical synthetic resins and aluminum), so that they are easy to separate and environmentally friendly, and at the same time, it can be confirmed that the processability into packaging materials and the seal strength, peel strength, and gas barrier property that the packaging materials should have are ensured.

[0101] On the other hand, for the laminates of Comparative Examples 1 to 6, it is impossible to form the film itself (Comparative Example 3), or even after the resin composition for forming the film layer is extrusion-coated on the paper substrate, the physical properties are significantly deteriorated, and it is difficult to process into packaging materials, or it is difficult to use for packaging foods, cosmetics, etc.

[0102] These results support the need to optimize the bio-carbon content, physical properties, etc. of each of the paper layer and the film layer as disclosed herein when manufacturing a laminate including a paper layer and a film layer.

Explanation of Signs

[0103] 10: Laminate 11: Paper layer 12: Film layer 13: Adhesive layer

Claims

1. A laminate comprising a paper layer and a film layer, wherein the paper layer has a biocarbon content of 85% or more and a tensile strength of 8 MPa or more, the film layer contains polyhydroxyalkanoate (PHA), and has a thickness of 8 to 70 μm, the polyhydroxyalkanoate (PHA) is a homopolymer containing repeating units derived from monomers selected from the group consisting of 3-hydroxypropionic acid (3HP), 4-hydroxybutyrate (4HB), 3-hydroxyvalerate (3HV), 5-hydroxyvalerate (5HV), 3-hydroxyhexanoate (3HH), 6-hydroxyhexanoate (6HH), and 3-hydroxyoctanoate (3HO), or a copolymer containing at least one repeating unit derived from monomers selected from the group consisting of 3-hydroxybutyrate (3HB), 3-hydroxypropionic acid (3HP), 4-hydroxybutyrate (4HB), 3-hydroxyvalerate (3HV), 5-hydroxyvalerate (5HV), 3-hydroxyhexanoate (3HH), 6-hydroxyhexanoate (6HH), and 3-hydroxyoctanoate (3HO), and containing the at least one repeating unit in an amount of 0.1 to 50% by weight, a laminate wherein the thickness of the film layer is less than 75% of the total thickness of the laminate.

2. The laminate according to claim 1, wherein the polyhydroxyalkanoate (PHA) is a copolymer containing a first repeating unit and a second repeating unit, and the first repeating unit and the second repeating unit are each derived from monomers selected from the group consisting of 3-hydroxybutyrate (3HB), 3-hydroxypropionic acid (3HP), 4-hydroxybutyrate (4HB), 3-hydroxyvalerate (3HV), 5-hydroxyvalerate (5HV), 3-hydroxyhexanoate (3HH), 6-hydroxyhexanoate (6HH), and 3-hydroxyoctanoate (3HO), and the first repeating unit and the second repeating unit are different from each other.

3. The laminate according to claim 2, wherein the polyhydroxyalkanoate (PHA) is a copolymer containing the first repeating unit or the second repeating unit in an amount of 0.1 to 50% by weight based on the total weight of the polyhydroxyalkanoate (PHA).

4. The polyhydroxyalkanoate (PHA) is a copolymer containing, based on the total weight of the polyhydroxyalkanoate (PHA), 50 to 99.9% by weight of a first repeating unit derived from 3-hydroxybutyrate (3HB), and 0.1 to 50% by weight of a second repeating unit derived from a monomer selected from the group consisting of 3-hydroxypropionic acid (3HP), 4-hydroxybutyrate (4HB), 3-hydroxyvalerate (3HV), 5-hydroxyvalerate (5HV), 3-hydroxyhexanoate (3HH), 6-hydroxyhexanoate (6HH), and 3-hydroxyoctanoate (3HO). The laminate according to claim 2.

5. The film layer has a biocarbon content of 40% or more. The laminate according to claim 1.

6. The oxygen permeability is 1 to 1,200 cc / m ２ ·day, and the water vapor permeability is 1 to 150 g / m ２ ·day, the laminate according to claim 1.

7. The film layer has a tensile strength of 5 MPa or more and a seal strength of 0.5 kgf or more. The laminate according to claim 1.

8. The film layer further contains one or more selected from the group consisting of polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), thermoplastic starch (TPS), polyvinyl alcohol (PVA), polycaprolactone (PCL), bio-derived polyethylene, and bio-derived polypropylene. The laminate according to claim 1.

9. The polyhydroxyalkanoate (PHA) is a poly(3-hydroxybutyrate-co-4-hydroxybutyrate) copolymer. The laminate according to claim 1.

10. The polyhydroxyalkanoate (PHA) has an average molecular weight of 30,000 to 1,000,000 g / mol. The laminate according to claim 1.

11. The paper layer has a tensile strength of 8 to 100 MPa, a tear strength of 20 to 600 gf, and a basis weight of 30 to 350 g / m ２ The laminate according to claim 1, which is as described above.

12. The peel strength is 200 gf or more. The laminate according to claim 1.

13. The total biocarbon content is 25% or more. The laminate according to claim 1.

14. A packaging material containing the laminate according to any one of claims 1 to 13.

Images