Packaging film, packaging container, and packaging product

Abstract

To provide a packaging film, a packaging container, and a packaging product, allowing for improvement in antistatic performance.SOLUTION: A packaging film includes a substrate layer and a sealant layer, wherein an antistatic layer is disposed between the substrate layer and the sealant layer, and the antistatic layer contains conductive particles. The conductive particles may be metal particles. The larger absolute value of electrostatic potentials measured at 20°C and 65% RH for the substrate layer and sealant layer may be 1.0 kV or less.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a packaging film, a packaging container, and a packaged product.

Background Art

[0002] In recent years, packaging films used for packaging contents such as food, pharmaceuticals, and electronic components have been required to have an antistatic function from the viewpoints of preventing adhesion of powders, proper filling of the contents, and preventing double-sheet picking when filling the contents.

[0003] For example, in Patent Document 1 below, in order to suppress the adhesion of powders, a laminate is proposed that includes a base material and a sealant layer, the base material includes a stretched polyethylene layer and a surface layer provided on the stretched polyethylene layer, the surface layer contains an antistatic agent, the stretched polyethylene layer is arranged so as to face the sealant layer side, and the sealant layer contains polyethylene as a main component.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the laminate described in Patent Document 1 above had the following problems. That is, the laminate described in Patent Document 1 above had room for improvement in terms of antistatic properties. The present disclosure has been made in view of the above problems, and an object thereof is to provide a packaging film, a packaging container, and a packaged product capable of improving antistatic properties.

Means for Solving the Problems

[0006] To solve the above problems, one aspect of the present disclosure provides a packaging film including a base material layer and a sealant layer, the packaging film including an antistatic layer between the base material layer and the sealant layer, the antistatic layer including conductive particles. According to the packaging film, antistatic properties can be improved as compared with a packaging film having no antistatic layer between the base material layer and the sealant layer. The inventors of the present disclosure presume that the reason for obtaining the above effect is as follows. That is, it is considered that the charge attached from the outside effectively passes through the base material layer or the sealant layer and is attracted into the antistatic layer, so that the amount of charge remaining on the surface of the base material layer or the surface of the sealant layer is effectively reduced.

[0007] The conductive particles are preferably metal particles. In this case, the antistatic properties can be effectively improved without increasing the proportion of the metal particles. Therefore, this packaging film is excellent in recyclability.

[0008] It is preferable that the absolute value of the electrostatic potential of the base material layer and the sealant layer at 20°C and 65% RH is 1.0 kV or less. In this case, adhesion of powder to the base material layer and the sealant layer can be effectively suppressed.

[0009] The packaging film may further include a barrier layer between the base material layer and the sealant layer. Since this packaging film includes a barrier layer, gas barrier properties can be improved.

[0010] The barrier layer may include a barrier base material and an inorganic oxide layer provided on the barrier base material. This packaging film can contribute to suppressing adverse environmental impacts as compared with a packaging film using a metal layer such as an aluminum foil that emits a large amount of carbon dioxide during production as a barrier layer. In particular, this packaging film can contribute more effectively to suppressing adverse environmental impacts as compared with the case of using a metal layer instead of the inorganic oxide layer.

[0011] The above packaging film may be used for the hydrothermal treatment.

[0012] Another aspect of the present disclosure provides a packaging container obtained by using the above-described packaging film. Since this packaging container can improve the antistatic property, it is difficult to be charged, and even when the content is stored in the packaging container, the adverse effect on the content due to charging can be suppressed.

[0013] Still another aspect of the present disclosure provides a packaging product including the above packaging container and the content stored in the packaging container. According to this packaging product, since the packaging container can improve the antistatic property, it is difficult to be charged, and the adverse effect on the content due to charging can be suppressed. Therefore, a decrease in the quality of the packaging product can be suppressed.

Effects of the Invention

[0014] According to the present disclosure, there are provided a packaging film, a packaging container, and a packaging product that can improve the antistatic property.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present disclosure will be described in detail. However, the present invention is not limited to the following embodiments.

[0017] <Packaging Film> First, an embodiment of the packaging film of the present disclosure will be described with reference to FIG. 1. FIG. 1 is a cross-sectional view showing an embodiment of the packaging film of the present disclosure.

[0018] The packaging film 100 shown in FIG. 1 includes a base material layer 10 and a sealant layer 40. The packaging film 100 includes an antistatic layer 20 between the base material layer 10 and the sealant layer 40. The antistatic layer 20 contains conductive particles.

[0019] Note that the packaging film 100 may further include a barrier layer 30 between the base material layer 10 and the sealant layer 40. Further, the packaging film 100 may further include a printing layer provided on at least one of the base material layer 10, the antistatic layer 20, and the barrier layer 30. In the packaging film 100, the base material layer 10, the antistatic layer 20, the barrier layer 30, and the sealant layer 40 can be laminated by a dry lamination method or an extrusion lamination method or the like. That is, the base material layer 10, the antistatic layer 20, the barrier layer 30, and the sealant layer 40 can be bonded together by an adhesive layer.

[0020] According to the above packaging film 100, the antistatic property can be improved as compared with a packaging film that does not have the antistatic layer 20 between the base material layer 10 and the sealant layer 40. Further, since the packaging film 100 includes the antistatic layer 20 between the base material layer 10 and the sealant layer 40, the conductive particles in the antistatic layer 20 are difficult to detach, and it is also possible to suppress contamination of the contents contained in the packaging container obtained by using the packaging film 100 and filling machines and the like. Further, it is also possible to suppress peeling of the antistatic layer 20 and to maintain the antistatic property.

[0021] Hereinafter, the base material layer 10, the printing layer, the barrier layer 30, the sealant layer 40, the adhesive layer, the antistatic layer 20, and the packaging film 100 will be described in detail.

[0022] (1) Base material layer The base material layer 10 serves as a support layer of the packaging film 100 and contains a resin. Examples of the resin contained in the base material layer 10 include polyolefin resins and polyester resins. Examples of polyolefin resins include polyethylene resins and polypropylene resins. Among polyolefin resins, polypropylene resins are preferred from the viewpoint of heat resistance.

[0023] Examples of polyethylene resins include high-density polyethylene (HDPE), medium-density polyethylene (MDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and very-low-density polyethylene (VLDPE). These can be used alone or in combination of two or more.

[0024] Examples of polypropylene resins include homopolymers, random copolymers, and block copolymers. These can be used alone or in combination of two or more. A homopolymer is a homopolymer of propylene, a polypropylene random copolymer is a random copolymer of propylene and an α-olefin other than propylene (e.g., ethylene, 1-butene, 4-methyl-1-pentene, etc.), and a polypropylene block copolymer is a copolymer having a polymer block composed of propylene and a polymer block composed of an α-olefin other than propylene described above.

[0025] Examples of polyester resins include polyethylene terephthalate resin (PET) and polyethylene naphthalate resin (PEN).

[0026] The resin contained in the base material layer 10 may be a resin derived from biomass or a resin recycled mechanically or chemically.

[0027] The base material layer 10 may have a single-layer structure or a multilayer structure. When the base material layer 10 has a multilayer structure, each layer may be laminated by dry lamination or extruder lamination.

[0028] The base material layer 10 may be a stretched film or an unstretched film, but from the viewpoint of gas barrier properties, it is preferably a stretched film. Here, examples of the stretched film include a uniaxially stretched film and a biaxially stretched film, but a biaxially stretched film is preferred in order to improve the heat resistance of the packaging film 100.

[0029] The content of the resin in the base material layer 10 is preferably 80% by mass or more, and more preferably 85% by mass or more.

[0030] The base material layer 10 may further contain an additive as necessary. Examples of the additive include a crosslinking agent, an antioxidant, an antiblocking agent, a slip agent, an ultraviolet absorber, a light stabilizer, a flame retardant, a reinforcing agent, an inorganic filler, an organic filler, a dye, a pigment, and the like.

[0031] The thickness of the base material layer 10 may be 15 μm or more, and may also be 20 μm or more. The thickness of the base material layer 10 may be 200 μm or less, may also be 150 μm or less, and may also be 100 μm or less. The thickness of the base material layer 10 is preferably 15 to 200 μm. In this case, processing such as printing and laminating on the base material layer 10 becomes easy.

[0032] The base material layer 10 may be surface-treated. The method of the surface treatment is not particularly limited, and examples thereof include corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas and / or nitrogen gas, glow discharge treatment, and oxidation treatment using a chemical.

[0033] (2) Printing layer The printing layer is provided on at least one layer (hereinafter also referred to as "printed layer") of the base material layer 10, the antistatic layer 20, and the barrier layer 30. The printing layer may be provided on only one side of the printed layer, or may be provided on both sides of the printed layer. The printing layer includes an image composed of characters, patterns, symbols, and combinations thereof. The printing layer can be formed using ink. The ink contains a colorant. The ink may further contain a resin. Also, the ink may further contain a plasticizer, a desiccant, a stabilizer, etc., as necessary.

[0034] The ink may be a water-based ink or an oil-based ink, but a water-based ink is preferred. Since water or alcohol is used as a solvent for the water-based ink, the environmental load can be further reduced. Also, the ink may or may not be a biomass ink, but from the viewpoint of reducing the environmental load, it is preferably a biomass ink. Here, the biomass ink refers to an ink containing components obtained from biological resources (biomass) such as cotton, pulp, rice bran, vegetable oil, and seeds of angiosperms. The method for forming the printing layer is not particularly limited, and examples of the method for forming the printing layer include printing methods such as gravure printing, offset printing, and flexographic printing. The printing layer may have a single-layer structure or a multilayer structure.

[0035] (3) Barrier layer The barrier layer 30 is a layer for improving gas barrier properties and can be composed of, for example, a laminate including a barrier substrate and an inorganic oxide layer. In this case, since the inorganic oxide layer is supported by the barrier substrate, even when stress is applied to the barrier layer 30, the stress is relaxed by the barrier substrate, and cracks are less likely to occur in the inorganic oxide layer. Also, the packaging film 100 can contribute to suppressing adverse environmental impacts compared to a packaging film using a metal layer such as an aluminum foil that emits a large amount of carbon dioxide during production as the barrier layer 30. The laminate may further include at least one of an anchor coat layer and an overcoat layer. By the packaging film 100 including the barrier layer 30, the packaging film 100 can have barrier properties against gases such as oxygen and water vapor.

[0036] (Barrier substrate) The barrier base material may contain the same resin as the resin contained in the base material layer 10. Specifically, the barrier base material may contain resins such as polyolefin resins and polyester resins. Examples of the polyolefin resin include polyethylene resins and polypropylene resins.

[0037] Examples of the polyester resin include polyethylene terephthalate resin (PET) and polyethylene naphthalate resin (PEN). In addition, the surface of the barrier base material on the side of the inorganic oxide layer may be subjected to plasma treatment or the like.

[0038] (Inorganic oxide layer) The inorganic oxide layer contains an inorganic oxide. Since the inorganic oxide layer further suppresses the permeation of oxygen and water vapor, the storage stability of the contents in the packaging container formed using the packaging film 100 is further improved. Also, when the inorganic oxide layer contains an inorganic oxide, the packaging film 100 can contribute more effectively to suppressing adverse environmental impacts compared to the case where it contains a metal.

[0039] Examples of the inorganic oxide include aluminum oxide and silicon oxide. The inorganic oxide layer may be a layer that sufficiently transmits visible light (transparent or translucent). In this case, the color and transparency of the contents can be easily visually recognized from the outside, and the barrier layer 30 can be called a transparent barrier film.

[0040] The inorganic oxide layer may be a vapor deposition layer. The vapor deposition layer can be formed on the surface of the barrier base material by a vapor deposition method such as physical vapor deposition or chemical vapor deposition.

[0041] The thickness of the inorganic oxide layer may be 5 nm or more, and may be 10 nm or more. When the thickness of the inorganic oxide layer is 5 nm or more, the packaging film 100 is likely to exhibit sufficient barrier properties. The thickness of the inorganic oxide layer may be 100 nm or less, and may also be 30 nm or less. When the thickness of the inorganic oxide layer is 100 nm or less, it becomes easier to suppress the deterioration of the barrier property due to cracks in the inorganic oxide layer.

[0042] (Anchor coat layer) The anchor coat layer is a layer for further improving the adhesion between the barrier substrate and the inorganic oxide layer, and is provided between the barrier substrate and the inorganic oxide layer.

[0043] The material constituting the anchor coat layer may include a polyurethane resin. The polyurethane resin is composed of, for example, a reaction product of an organosilane or an organometallic compound, a polyol compound, and an isocyanate compound.

[0044] (Overcoat layer) The overcoat layer is composed of a gas barrier coating film formed using a resin composition containing a metal alkoxide and a water-soluble polymer. The resin composition may further contain a silane coupling agent in addition to the metal alkoxide and the water-soluble polymer. The overcoat layer can be formed on the inorganic oxide layer by a coating method such as roll coating, gravure roll coating, kiss coating, or a printing method such as gravure printing, offset printing, or transfer printing using the above resin composition.

[0045] (4) Sealant layer The sealant layer 40 is a surface substrate layer having heat sealability and contains a resin. By including the sealant layer 40 in the packaging film 100, a packaging container can be formed by heat-sealing it with the sealant layer 40 of another packaging film 100.

[0046] Examples of the resin contained in the sealant layer 40 include polyolefin resins and polyester resins. Examples of the polyolefin resin include polyethylene resins and polypropylene resins. Examples of the polyethylene resin include high-density polyethylene (HDPE), medium-density polyethylene (MDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and very-low-density polyethylene (VLDPE). These can be used alone or in combination of two or more. Examples of the polypropylene resin include homopolymers, random copolymers, and block copolymers.

[0047] Examples of the polyester resin include polyethylene terephthalate resin (PET) and polyethylene naphthalate resin (PEN). The resin contained in the sealant layer 40 may be a resin derived from biomass or a resin that has been mechanically recycled or chemically recycled.

[0048] The sealant layer 40 may have a single-layer structure or a multilayer structure. When the sealant layer 40 has a multilayer structure, each layer may be laminated by dry lamination or extruder lamination.

[0049] The sealant layer 40 may further contain additives as needed. Examples of the additives include crosslinking agents, antioxidants, antiblocking agents, slip agents, ultraviolet absorbers, light stabilizers, flame retardants, reinforcing agents, antistatic agents, inorganic fillers, organic fillers, dyes, pigments, and the like.

[0050] The sealant layer 40 may be a stretched film or an unstretched film, but from the viewpoint of heat sealability, it is preferably an unstretched film. Examples of the stretched film include uniaxially stretched films and biaxially stretched films.

[0051] The content of the resin in the sealant layer 40 is preferably 85% by mass or more, and more preferably 95% by mass or more. The melting point of the sealant layer 40 is preferably lower than the melting point of the base material layer 10. In this case, it becomes easier to process the packaging film 100 into a packaging container.

[0052] The thickness of the sealant layer 40 may be 50 μm or more, and may also be 100 μm or more. When the thickness of the sealant layer 40 is 50 μm or more, it becomes easier to obtain sufficient seal strength and excellent self-standing property when producing a packaging container by bonding packaging films 100 together with the sealant layer 40. The thickness of the sealant layer 40 may be 180 μm or less, may also be 150 μm or less, and may also be 100 μm or less.

[0053] (5) Adhesive layer When the adhesive layer is formed by the dry lamination method, it can be formed using an adhesive. Specifically, the adhesive layer is formed by applying an adhesive by a coating method such as roll coating, gravure roll coating, kiss coating, or a printing method such as gravure printing, offset printing, or transfer printing, and then drying.

[0054] The amount of adhesive used (mass per unit area of the adhesive layer) is not particularly limited, but may be 0.1 to 10 g / m 2 in the dry state, and may also be 1 to 5 g / m 2 in the dry state. As the adhesive, it is preferable to use a polyurethane-based adhesive. In this case, excellent flexibility and bendability can be imparted to the adhesive layer. Also, by using a polyurethane-based adhesive, the processability such as lamination processing and printing processing is likely to be improved. As the polyurethane-based adhesive, for example, an adhesive mainly composed of a polyether polyurethane-based resin, a polyester polyurethane-based resin, or a polyacrylate polyurethane-based resin can be used.

[0055] The adhesive may be in any form of aqueous type, solution type, emulsion type, dispersion type, two-component curing type, or solvent-free type. Also, the adhesive may be in any form such as film form, sheet form, powder form, or solid form. The reaction mechanism of the adhesive is not particularly limited, and may be any of chemical reaction type, solvent evaporation type, heat welding type, heat pressing type, etc. From the perspective of reducing environmental impact, the adhesive is preferably a biomass adhesive. Here, the biomass adhesive refers to an adhesive containing components obtained from biological resources (biomass) such as cotton, pulp, rice bran, vegetable oil, and seeds of angiosperms.

[0056] As the adhesive, an adhesive that imparts barrier properties to the adhesive layer (barrier adhesive) may be used.

[0057] When the adhesive layer is formed by the extrusion lamination method, it is formed using an adhesive resin. The adhesive resin is a heat-fusible adhesive thermoplastic resin, and any resin that can be melted by heat and fused with each other may be used. For example, low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear (linear) low-density polyethylene, polypropylene, ethylene-propylene copolymer, methylpentene polymer, polyolefin resins such as polyethylene or polypropylene modified with unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, and others can be used.

[0058] The thickness of the adhesive layer can be appropriately determined according to the purpose, but it may be in the range of 1 to 100 μm.

[0059] (6) Antistatic layer The antistatic layer 20 contains conductive particles. Examples of the conductive particles include carbon nanofibers, particles with the surface of resin particles coated with a metal layer, and metal particles. Among them, metal particles are preferred. In this case, the antistatic property can be effectively improved without increasing the proportion of metal particles. Therefore, this packaging film 100 is excellent in recyclability. The metal particles may be aluminum, copper, silver, etc., but aluminum is preferred. Aluminum is less likely to rust and less likely to become an insulating oxide, and it is easy to maintain the antistatic effect. Also, aluminum is lighter than copper and silver, and the packaging film 100 can be lightened.

[0060] The average particle diameter of the conductive particles is not particularly limited, but is preferably 10 μm or more. In this case, since the surface area of the conductive particles increases, it becomes easier for the packaging film 100 to further improve the antistatic property. The average particle diameter of the conductive particles may be 15 μm or more, or may be 20 μm or more. The average particle diameter of the conductive particles may be 30 μm or less, or may be 25 μm or less.

[0061] The content rate of the conductive particles in the antistatic layer 20 is not particularly limited as long as it is more than 0% by mass, but is preferably 1% by mass or more. In this case, the packaging film 100 can effectively improve the antistatic property. The content rate of the conductive particles in the antistatic layer 20 may be 5% by mass or more, or may be 10% by mass or more. The content rate of the conductive particles in the antistatic layer 20 is preferably 20% by mass or less. In this case, compared with the case where the content rate of the conductive particles in the antistatic layer 20 exceeds 20% by mass, the adhesion to the base material layer 10 can be further improved.

[0062] The thickness of the antistatic layer 20 is preferably 1 μm or more, and more preferably 1.5 μm or more. By the thickness of the antistatic layer 20 being 1.5 μm or more, the packaging film 100 can effectively improve the antistatic property. The thickness of the antistatic layer 20 may be 10 μm or less, may be 5 μm or less, or may be 3 μm or less.

[0063] In FIG. 1, the antistatic layer 20 is provided between the base material layer 10 and the barrier layer 30, but may be provided between the barrier layer 30 and the sealant layer 40. In this case, the barrier base material of the barrier layer 30 may also serve as the base material layer 10. Further, the barrier layer 30 may also serve as the antistatic layer 20.

[0064] (7) Packaging film In the packaging film 100, it is preferable that the resins contained in the base material layer 10, the barrier base material, and the sealant layer 40 are all polyolefin resins or polyester resins. In this case, the recyclability of the packaging film 100 is further improved.

[0065] The content of the polyolefin resin or the polyester resin is preferably 80% by mass or more, more preferably 85% by mass or more, based on the total mass of the packaging film 100. The upper limit of the content of the polyolefin resin or the polyester resin is not particularly limited, but can be 98% by mass from the viewpoint of recyclability.

[0066] The polyolefin resin may be a polyethylene resin or a polypropylene resin.

[0067] The polyester resin may be polyethylene terephthalate (PET) or polyethylene naphthalate (PEN). In the packaging film 100, the polyolefin resin or the polyester resin contained in the base material layer 10, the barrier base material, and the sealant layer 40 may include mechanically recycled resin or chemically recycled resin. Further, the polyolefin resin or the polyester resin contained in the base material layer 10, the barrier base material, and the sealant layer 40 may be a resin containing a biomass-derived component. The absolute value of the electrostatic potential of the base material layer 10 and the sealant layer 40 at 20°C and 65% RH is preferably 1.0 kV or less. That is, when the absolute values of the electrostatic potentials of the base material layer 10 and the sealant layer 40 at 20°C and 65% RH are the same value, it is preferably 1.0 kV or less, and when they are different values, the larger value is preferably 1.0 kV or less. In this case, the adhesion of powder to the base material layer 10 and the sealant layer 40 can be effectively suppressed. It is more preferable that the absolute value of the electrostatic potential of the base material layer 10 and the sealant layer 40 at 20°C and 65% RH is 0.6 kV or less, more preferably 0.5 kV or less, and particularly preferably 0.4 kV or less. The absolute value of the electrostatic potential of the base material layer 10 and the sealant layer 40 at 20°C and 65% RH may both be 0 kV or less.

[0068] The thickness of the packaging film 100 is not particularly limited and may be 50 to 500 μm.

[0069] The packaging film 100 may be used for hydrothermal treatment. Examples of the hydrothermal treatment include retort treatment and boiling treatment.

[0070] <Packaged product> Next, an embodiment of the packaged product of the present disclosure will be described with reference to FIG. 2. Note that FIG. 2 is a cross-sectional view showing an embodiment of the packaged product of the present disclosure. In FIG. 2, the same components as those in FIG. 1 are denoted by the same reference numerals, and redundant descriptions are omitted. As shown in FIG. 2, the packaged product 400 includes a packaging container 300 and a content C accommodated in the packaging container 300. The packaging container 300 shown in FIG. 2 is obtained by using a pair of packaging films 100 and heat-sealing the peripheral portions of the packaging films 100 with the sealant layers 40 facing each other.

[0071] In this packaged product 400, since the packaging container 300 can improve the antistatic property, it is difficult to be charged, and the adverse effect on the content C due to charging can be suppressed. Therefore, a decrease in the quality of the packaged product 400 can be suppressed.

[0072] Note that the packaging container 300 can also be obtained by folding one packaging film 100 and heat-sealing the peripheral portions of the packaging film 100 with the sealant layers 40 facing each other.

[0073] The packaging container 300 shown in Fig. 2 is a four-sided pouch, but the packaging container of the present disclosure is not limited to four-sided pouches, and can be used for various pouches such as three-sided pouches, standing pouches, gusset pouches, standing pouches, pouches with stoppers, gusset pouches, retort pouches, etc., as well as packaging containers such as sachets and gussets, and tubes such as laminated tubes.

[0074] The content C is not particularly limited, and examples of the content C include foods, liquids or liquid substances (such as jelly), pharmaceuticals, electronic components, and the like. When the content C of the packaging product 400 is a food, a liquid or a liquid substance (such as jelly), the packaging product 400 may further include a stopper.

[0075] <Summary of the Present Disclosure> The summary of the present disclosure is as follows. [1] A packaging film including a base material layer and a sealant layer, wherein an antistatic layer is provided between the base material layer and the sealant layer, and the antistatic layer contains conductive particles. [2] The packaging film according to claim 1, wherein the conductive particles are metal particles. [3] The packaging film according to [1] or [2], wherein the larger absolute value of the electrostatic potential at 20°C and 65% RH of the base material layer and the sealant layer is 1.0 kV or less. [4] The packaging film according to any one of [1] to [3], further including a barrier layer between the base material layer and the sealant layer. [5] The packaging film according to [4], wherein the barrier layer includes a barrier base material and an inorganic oxide layer provided on the barrier base material. [6] The packaging film according to any one of [1] to [5], which is used for hydrothermal treatment. [7] A packaging container obtained by using the packaging film according to any one of [1] to [6]. [8] A packaging product including the packaging container according to [7] and a content accommodated in the packaging container.

Examples

[0076] Hereinafter, the present disclosure will be specifically described with reference to examples, but the present disclosure is not limited to these examples.

[0077] (Example 1) First, as a base material layer, a biaxially stretched polypropylene film with a thickness of 20 μm (hereinafter also referred to as “OPP film”. Trade name “U-1”, manufactured by Mitsui Chemicals Toagosei Co., Ltd.) was prepared. On this OPP film, an antistatic coating agent (high-blocking ink manufactured by Tokyo Ink) containing 5% by mass of aluminum pigment and 95% by mass of vinyl chloride-vinyl acetate copolymer was applied and dried to form an antistatic layer with a thickness of 2 μm, and a first laminate was obtained. On the other hand, as a barrier base material, an OPP film with a thickness of 20 μm (trade name “U-1”, manufactured by Mitsui Chemicals Toagosei Co., Ltd.) was prepared. On this OPP film, a vapor deposition layer with a thickness of 30 nm made of silicon oxide was formed to obtain a barrier layer. Then, a first adhesive layer was formed on the antistatic layer of the first laminate using an adhesive for dry lamination. As the adhesive for dry lamination, a two-component reaction type polyester polyurethane resin (trade name “A626”, manufactured by Mitsui Chemicals, Inc.) was used. At this time, the thickness of the first adhesive layer after drying was set to 3 μm. Next, the barrier base material of the barrier layer and the first adhesive layer formed on the first laminate were laminated together to obtain a second laminate (base material layer / antistatic layer / first adhesive layer / barrier layer (barrier base material / vapor deposition layer)). Next, a second adhesive layer was formed on the vapor deposition layer of the second laminate using an adhesive for dry lamination. As the adhesive for dry lamination, a two-component reaction type polyester polyurethane resin (trade name “A626”, manufactured by Mitsui Chemicals, Inc.) was used. At this time, the thickness of the second adhesive layer after drying was set to 3 μm. Finally, on the surface of the second adhesive layer, as a sealant layer, an LLDPE film with a thickness of 100 μm (manufactured by Mitsui Chemicals Toagosei Co., Ltd., type: general grade, item “TC-S”) was attached. Thus, a packaging film was produced.

[0078] (Comparative Example 1) A packaging film was produced in the same manner as in Example 1, except that a first adhesive layer was formed on the OPP film surface of the first laminate.

[0079] (Example 2) A packaging film of Example 2 was produced in the same manner as in Example 1, except that a CPP film with a thickness of 60 μm (manufactured by Mitsui Chemicals Toagosei Co., Ltd., type: general grade, item "GLC") was used as the sealant layer.

[0080] (Comparative Example 2) A packaging film was produced in the same manner as in Example 2, except that a first adhesive layer was formed on the OPP film surface of the first laminate.

[0081] (Example 3) As the barrier substrate, a non-stretched high-density polyethylene film with a thickness of 32 μm (manufactured by Tamapoly Co., Ltd., grade "HD") was used, and as the substrate layer, a non-stretched high-density polyethylene film with a thickness of 30 μm (manufactured by Tamapoly Co., Ltd., grade "HD") was used. When forming the second adhesive layer, as the adhesive, an epoxy-based adhesive A prepared by mixing 16 parts by mass of Maxcebu C93T manufactured by Mitsubishi Gas Chemical Company and 5 parts by mass of Maxcebu M-100 manufactured by Mitsubishi Gas Chemical Company in 23 parts by mass of a solvent obtained by mixing ethyl acetate and methanol at a mass ratio of 1:1 was used. Adhesive A was applied onto the vapor deposition layer using a wire bar to form a coating film, and the coating film was dried at 60 °C to form a gas barrier adhesive layer (thickness: 3 μm). A packaging film (substrate layer / antistatic layer / first adhesive layer / barrier layer (barrier substrate / vapor deposition layer) / second adhesive layer (barrier adhesive) / sealant layer) was obtained in the same manner as in Example 1.

[0082] (Comparative Example 3) A packaging film was produced in the same manner as in Example 3, except that a first adhesive layer was formed on the OPP film surface of the first laminate.

[0083] (Example 4) As the barrier substrate, a biaxially stretched PET film with a thickness of 12 μm (manufactured by Toyobo Co., Ltd., product name "E5102") was used. As the substrate layer, a biaxially stretched PET film with a thickness of 12 μm (manufactured by Toyobo Co., Ltd., product name "E5102") was used. A packaging film was produced in the same manner as in Example 1, except that a non-stretched PET film with a thickness of 30 μm (manufactured by Toyobo Co., Ltd., product name "DE046", hereinafter also referred to as "A-PET") was used as the sealant layer.

[0084] (Comparative Example 4) A packaging film was produced in the same manner as in Example 4, except that a first adhesive layer was formed on the OPP film surface of the first laminate.

[0085] <Evaluation Method> For the packaging films obtained in the examples and comparative examples, the gas barrier properties and antistatic properties before and after heat treatment were evaluated as follows.

[0086] (1) Gas barrier properties before and after heat treatment As the heat treatment, a boiling treatment of immersing in hot water at 90 °C for 10 minutes was performed. The gas barrier properties were evaluated using the oxygen permeability and water vapor permeability as indicators. The oxygen permeability was measured in accordance with the method of JIS K 7126-2 "Plastics - Films and Sheets - Test Method for Gas Permeability - Part 2: Isobaric Method". The results are shown in Table 1. The water vapor permeability was measured in accordance with JIS K 7129-2 "Plastics - Films and Sheets - Method for Determining Water Vapor Permeability - Part 2: Infrared Sensor Method". The results of the oxygen permeability and water vapor permeability before and after heat treatment are shown in Table 1.

[0087] (2) Antistatic property The antistatic property was evaluated based on the electrostatic potential measured for the substrate layer or the sealant layer after the Tribo test. The Tribo test was performed by charging by friction with 100 strokes using a Tribo type friction tester (manufactured by Fukuda Kikai Kogyo Co., Ltd., product name "RT300"). The measurement of the electrostatic potential was carried out using an electrification voltage measuring instrument (manufactured by Achilles Co., Ltd., product name "AS-mini") under the conditions of 20°C and 65% RH. The results are shown in Table 1. In Table 1, the absolute value of the electrostatic potential in the base material layer and the sealant layer is shown as the same value if they are the same, and the larger value if they are different.

[0088] [Table 1]

[0089] From the above, it was confirmed that according to the packaging film of the present disclosure, the antistatic property can be improved. [Explanation of Signs]

[0090] 10... base material layer, 20... antistatic layer, 30... barrier layer, 40... sealant layer, 100... packaging film, 300... packaging container, 400... packaged product, C... contents.

Claims

1. A packaging film comprising a base material layer and a sealant layer, wherein an antistatic layer is provided between the base material layer and the sealant layer, and the antistatic layer contains conductive particles, the packaging film.

2. The packaging film according to Claim 1, wherein the conductive particles are metal particles.

3. The packaging film according to Claim 1, wherein the absolute value of the electrostatic potential at 20°C and 65% RH of the base material layer and the sealant layer is 1.0 kV or less.

4. The packaging film according to Claim 1, further comprising a barrier layer between the base material layer and the sealant layer.

5. The packaging film according to Claim 4, wherein the barrier layer comprises a barrier base material and an inorganic oxide layer provided on the barrier base material.

6. The packaging film according to Claim 1, which is used for hydrothermal treatment.

7. A packaging container obtained by using the packaging film according to any one of Claims 1 to 6.

8. A packaging product comprising the packaging container according to Claim 7 and contents contained in the packaging container.

Images