Laminated film, packaging bag, and package

Abstract

To provide a laminated film which can improve tearability along a half-cut line formed by a laser beam while maintaining good recyclability, and to provide a packaging bag and a package.SOLUTION: A laminated film including a base material layer and a sealant layer containing a polyolefin resin, wherein the base material layer includes a first resin layer containing a polyolefin resin and a second resin layer containing a laser light absorbing resin, the laser light absorbing resin absorbs laser light used for forming a half-cut line, the polyolefin resin contained in the sealant layer and the first resin layer does not absorb laser light, and the total content of the polyolefin resin in the entire laminated film is 90% by mass or more.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a laminated film, a packaging bag, and a package. [Background technology]

[0002] In recent years, there has been an increasing demand for the creation of a recycling-oriented society with less environmental impact, and in response to this, attempts have been made to recycle and reuse packaging materials. For example, Patent Document 1 below proposes a polyethylene laminate for packaging material that includes at least a stretched polyethylene film and a heat-sealable polyethylene layer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-166810 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in a package in which contents are contained in a packaging bag, it is known to form a half-cut line on the surface of the packaging bag in order to make it easier to open the package.

[0005] However, the polyethylene laminate for packaging materials described in Patent Document 1 mentioned above had the problem that even if an attempt was made to form a half-cut line in a packaging bag manufactured using the laminate using laser light from a carbon dioxide laser or the like, the half-cut line was not formed sufficiently, and even if it was formed, it was difficult to tear along the half-cut line.

[0006] Therefore, an object of the present disclosure is to provide a laminated film, a packaging bag, and a packaging body that can improve tearability along a half-cut line formed with laser light while maintaining good recyclability. [Means for solving the problem]

[0007] One aspect of the present disclosure is a laminate film comprising a base layer and a sealant layer containing a polyolefin resin, the base layer comprising a first resin layer containing a polyolefin resin and a second resin layer containing a laser beam-absorbing resin, wherein the laser beam-absorbing resin absorbs laser beams used to form half-cut lines, the polyolefin resins contained in the sealant layer and the first resin layer do not absorb the laser beams, and the total content of polyolefin resins in the entire laminate film is 90 mass% or more.

[0008] According to the laminate film of the present disclosure, the total content of polyolefin resin in the entire laminate film is 90 mass % or more, and therefore good recyclability can be maintained.

[0009] Furthermore, according to the laminate film of the present disclosure, the substrate layer includes a first resin layer containing a polyolefin resin and a second resin layer containing a laser-beam-absorbent resin. The laser-beam-absorbent resin contained in the second resin layer absorbs the laser beam used to form the half-cut line, while the polyolefin resin contained in the sealant layer and the first resin layer does not absorb the laser beam. Therefore, when laser beams are irradiated onto the laminate film from the substrate layer side to form the half-cut line, the laser beams reach the second resin layer without passing through the sealant layer and are irradiated onto the second resin layer with almost no attenuation. As a result, the laser-beam-absorbent resin absorbs the laser beam and is effectively burned away, effectively forming the half-cut line. Therefore, the laminate film of the present disclosure can maintain good recyclability while improving tearability along the half-cut line formed by the laser beam.

[0010] Furthermore, when a packaging bag is produced using the laminate film of the present disclosure, the sealant layer faces inward and the base layer including the second resin layer faces outward, so that the laminate film of the present disclosure makes it possible to easily form a half-cut line even after producing a packaging bag using the laminate film.

[0011] In the laminated film, the laser-light-absorbing resin is preferably made of at least one selected from the group consisting of polyethylene terephthalate, polyamide, and ethylene vinyl alcohol.

[0012] In this case, the laser-light-absorbing resin can effectively absorb the laser light used to form the half-cut line, thereby further improving the tearability along the half-cut line.

[0013] In the laminated film, the substrate layer is preferably obtained by coextrusion.

[0014] In this case, the base layer does not contain an adhesive layer that can absorb the laser light used to form the half-cut line, and the occurrence of interlayer delamination in the base layer can be more sufficiently suppressed, resulting in further improved tear resistance along the half-cut line.

[0015] In the laminated film, it is preferable that in the base layer, the laser-light-absorbent resin is polyamide, and the polyolefin resin contained in the first resin layer is linear low-density polyethylene.

[0016] In this case, the difference in viscosity between the first resin layer and the second resin layer is small, and therefore, when the base layer is obtained by co-extrusion, curvature of either the first resin layer or the second resin layer in the base layer is suppressed.

[0017] In the laminated film, it is preferable that the base layer comprises the second resin layer and two of the first resin layers arranged to sandwich the second resin layer, and that the laser beam absorbing resin is polyamide.

[0018] When the laser-beam-absorbing resin is polyamide, the second resin layer is likely to absorb moisture. In this laminate film, the second resin layer is sandwiched between two first resin layers in the base layer, which are more hydrophobic than the second resin layer, so that moisture is sufficiently prevented from penetrating the second resin layer. This prevents the second resin layer from expanding due to moisture absorption and causing the first resin layer to bend.

[0019] In the laminated film, it is preferable that the base layer comprises the second resin layer and two of the first resin layers arranged to sandwich the second resin layer, and the laser light-absorbing resin is polyethylene terephthalate.

[0020] When the laser beam-absorbing resin is polyethylene terephthalate, when the laser beam-absorbing resin absorbs laser beam, the laser beam-absorbing resin may be burned off, causing debris to fly around, or smoke to be generated. With this laminate film, the second resin layer is sandwiched between two first resin layers in the base layer, and therefore when the second resin layer absorbs laser beam, the second resin layer is sufficiently prevented from burning off, causing debris to fly around, or smoke to be generated.

[0021] The laminated film preferably further comprises a barrier layer between the base layer and the sealant layer, and has the first resin layer between the barrier layer and the second resin layer.

[0022] In this case, since the laminated film has the first resin layer between the barrier layer and the second resin layer, even when the base layer is irradiated with laser light, the influence of heat generated when the second resin layer is burned off by the laser light can be sufficiently prevented from reaching the barrier layer, thereby preventing damage to the barrier layer and reducing the barrier properties of the barrier layer.

[0023] Another aspect of the present disclosure is a packaging bag made using the laminated film described above, with the sealant layer facing inward and the base material layer facing outward.

[0024] According to the packaging bag of the present disclosure, the total content of polyolefin resin in the entire laminate film is 90% by mass or more, and therefore the packaging bag can maintain good recyclability.

[0025] Furthermore, according to the packaging bag of the present disclosure, the base layer of the laminated film includes a first resin layer containing a polyolefin resin and a second resin layer containing a laser-beam-absorbent resin. The laser-beam-absorbent resin contained in the second resin layer absorbs the laser beam used to form the half-cut line, while the polyolefin resin contained in the sealant layer and the first resin layer does not absorb the laser beam. Therefore, when laser beams are irradiated onto the laminated film from the base layer side of the packaging bag to form the half-cut line, the laser beams reach the second resin layer without passing through the sealant layer and are irradiated onto the second resin layer with almost no attenuation. As a result, the laser-beam-absorbent resin absorbs the laser beam and is effectively burned away, effectively forming the half-cut line. Therefore, the packaging bag of the present disclosure can maintain good recyclability while improving tearability along the half-cut line formed by the laser beam. This allows the packaging bag to be easily torn along the half-cut line.

[0026] Furthermore, according to the packaging bag of the present disclosure, the sealant layer faces inward and the base layer including the second resin layer faces outward, so that the half-cut line can be easily formed from the base layer side.

[0027] Yet another aspect of the present disclosure is a package including the above-described packaging bag and contents accommodated in the packaging bag.

[0028] According to the packaging body of the present disclosure, the total content of polyolefin resin in the entire laminate film constituting the packaging bag is 90 mass % or more, and therefore the packaging body can maintain good recyclability.

[0029] Furthermore, according to the packaging body of the present disclosure, in a laminate film constituting a packaging bag, the base layer includes a first resin layer containing a polyolefin resin and a second resin layer containing a laser-beam-absorbent resin layer. The laser-beam-absorbent resin contained in the second resin layer absorbs the laser beam used to form the half-cut line, while the polyolefin resin contained in the sealant layer and the first resin layer does not absorb the laser beam. Therefore, when laser beams are irradiated onto the laminate film from the base layer side of the packaging bag to form the half-cut line, the laser beams reach the second resin layer without passing through the sealant layer and are irradiated onto the second resin layer with almost no attenuation. As a result, the laser-beam-absorbent resin absorbs the laser beam and is effectively burned away, effectively forming the half-cut line. Therefore, according to the packaging body of the present disclosure, it is possible to improve tearability along the half-cut line formed by the laser beam while maintaining good recyclability. Therefore, the packaging body can be easily opened by tearing the packaging bag along the half-cut line, and the contents can be easily removed.

[0030] Furthermore, according to the packaging body of the present disclosure, in the packaging bag, the sealant layer faces inward and the base layer including the second resin layer faces outward, so that the half-cut line can be easily formed from the base layer side. [Effects of the Invention]

[0031] According to the present disclosure, a laminated film, a packaging bag, and a packaging body are provided that can improve tearability along a half-cut line formed with a laser beam while maintaining good recyclability. [Brief explanation of the drawings]

[0032] [Figure 1] 1 is a cross-sectional view showing one embodiment of a laminated film of the present disclosure. [Figure 2] FIG. 2 is a cross-sectional view showing another embodiment of the laminated film of the present disclosure. [Figure 3] FIG. 1 is a front view of one embodiment of a package of the present disclosure. [Figure 4]FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0033] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings as needed. However, the following embodiments are merely examples for explaining the present disclosure and are not intended to limit the present disclosure to the following content. In the description, the same reference numerals will be used for the same elements or elements having the same functions, and redundant description will be omitted as the case may be. Furthermore, the dimensional ratios of the drawings are not limited to those shown in the drawings.

[0034] <Laminated film> 1 is a cross-sectional view showing one embodiment of a laminate film according to the present disclosure. The laminate film 100 comprises, in this order, a base layer 10, an adhesive layer 30, and a sealant layer 20 containing a polyolefin resin. The base layer 10 comprises, from the adhesive layer 30 side, a first resin layer 12 containing a polyolefin resin, a second resin layer 11 containing a laser-beam-absorbing resin, and a first resin layer 13 containing a polyolefin resin, in this order. That is, in the base layer 10, the first resin layer 12 and the first resin layer 13 are disposed so as to sandwich the second resin layer 11 therebetween.

[0035] Here, the second resin layer 11 contains a laser-beam-absorbing resin that absorbs the laser beam used to form the half-cut line, while the polyolefin resin contained in the sealant layer 20 and the first resin layers 12, 13 does not absorb the laser beam. Also, in the laminate film 100, the total content of polyolefin resin in the entire laminate film 100 is 90 mass% or more.

[0036] According to the laminated film 100, the total content of polyolefin resin in the entire laminated film 100 is 90 mass % or more, and therefore good recyclability can be maintained.

[0037] Furthermore, in the laminate film 100, the base layer 10 includes a first resin layer 12 containing a polyolefin resin and a second resin layer 11 containing a laser-beam-absorbent resin. The laser-beam-absorbent resin contained in the second resin layer 11 absorbs the laser beam used to form the half-cut line, while the polyolefin resins contained in the sealant layer 20 and the first resin layers 12 and 13 do not absorb the laser beam. Therefore, when laser beams are irradiated onto the laminate film 100 from the base layer 10 side to form the half-cut line, the laser beams reach the second resin layer 11 without passing through the sealant layer 20, and are irradiated onto the second resin layer 11 with almost no attenuation. As a result, the laser-beam-absorbent resin absorbs the laser beams and is effectively burned away, effectively forming the half-cut line. Therefore, the laminate film 100 can maintain good recyclability while improving tearability along the half-cut line formed by the laser beam.

[0038] Furthermore, when a packaging bag is produced using the laminate film 100, the sealant layer 20 faces inward, and the base material layer 10 including the second resin layer 11 faces outward. Therefore, according to the laminate film 100, even after a packaging bag is produced using the laminate film 100, a half-cut line can be easily formed.

[0039] The laminated film 100 will be described in detail below.

[0040] In the laminate film 100, the total content of polyolefin resin in the entire laminate film 100 may be 90% by mass or more, but from the viewpoint of improving the recyclability of the laminate film 100, it is preferably 95% by mass or more.

[0041] However, the total content of polyolefin resin in the entire laminate film 100 is less than 100% by mass.

[0042] (base material layer) The base material layer 10 may be obtained by co-extrusion or by bonding the second resin layer 11 and each of the first resin layers 12 and 13 together via an adhesive using a dry lamination method, but it is preferable that it is obtained by co-extrusion.

[0043] In this case, the base layer 10 does not contain an adhesive layer that can absorb the laser light used to form the half-cut line, and the occurrence of interlayer delamination in the base layer 10 can be more sufficiently suppressed, thereby further improving the tearability along the half-cut line.

[0044] The thickness of the substrate layer 10 is not particularly limited and may be, for example, 10 μm or more or 50 μm or more. The thickness of the substrate layer 10 may be 100 μm or less or 60 μm or less. The thickness of the substrate layer 10 is adjusted appropriately depending on the application or desired properties.

[0045] (1)Second resin layer The second resin layer 11 only needs to contain a laser-beam-absorbent resin, and may be made entirely of the laser-beam-absorbent resin, or only partly of the second resin layer 11 may be made of the laser-beam-absorbent resin, for example.

[0046] The laser-absorbent resin may be made of a resin that absorbs the laser beam used to form the half-cut line. Here, "absorb" means that the resin is burned away by the laser beam used to form the half-cut line, forming a space.

[0047] Specific examples of the laser light used to form the half-cut line include laser light emitted from a carbon dioxide gas laser or a YAG laser.

[0048] Examples of the laser-beam-absorbing resin include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyamides such as nylon (e.g., 66-nylon), ethylene vinyl alcohol (EVOH), polybutylene terephthalate (PBT), etc. The above laser-beam-absorbing resins may be used either alone or in combination of two or more.

[0049] The laser-beam-absorbing resin may be a resin obtained using a raw material (monomer) obtained from a fossil fuel or a resin obtained using a raw material (monomer) derived from biomass, but from the viewpoint of reducing the environmental load, a resin obtained using a raw material derived from biomass is preferable. Alternatively, the laser-beam-absorbing resin may be a recycled resin. The recycled resin may be a mechanically recycled resin or a chemically recycled resin.

[0050] Of the above laser light-absorbing resins, polyethylene terephthalate, polyamide, ethylene vinyl alcohol, or a mixture of two or more of these is preferred. In this case, the laser-light-absorbing resin can effectively absorb the laser light used to form the half-cut line, thereby further improving the tearability along the half-cut line.

[0051] However, when the laser-beam-absorbent resin is polyamide, the second resin layer 11 usually tends to absorb moisture. In this regard, according to the laminate film 100, the second resin layer 11 in the base layer 10 is sandwiched between two first resin layers 12, 13 that are more hydrophobic than the second resin layer 11. This sufficiently prevents moisture from penetrating the second resin layer 11. This makes it possible to prevent the second resin layer 11 from expanding due to moisture absorption and causing the first resin layers 12, 13 to bend.

[0052] Furthermore, when the laser-beam-absorbing resin is polyethylene terephthalate, when the laser-beam-absorbing resin absorbs laser light, the laser-beam-absorbing resin may be burned off, causing debris to fly around, or smoke to be generated. In this regard, according to laminate film 100, second resin layer 11 is sandwiched between two first resin layers 12, 13 in base layer 10, and therefore when second resin layer 11 absorbs laser light, scattering of debris to fly around, or smoke to be generated is sufficiently suppressed.

[0053] The second resin layer 11 may contain at least one additive selected from a filler, an antistatic agent, a plasticizer, a lubricant, an antioxidant, and the like.

[0054] The second resin layer 11 may be formed by laminating a plurality of the same types of films. The second resin layer 11 may be formed of either a stretched or unstretched film. It may also be formed by laminating at least one stretched film and at least one unstretched film. The second resin layer 11 can improve mechanical strength and dimensional stability by including a film that has been arbitrarily stretched in biaxial directions.

[0055] The thickness of the second resin layer 11 is not particularly limited and may be, for example, 1 to 40 μm, but is preferably 5 to 30 μm, which can improve recyclability while maintaining sufficient ease of cutting.

[0056] (2) First resin layer The first resin layers 12, 13 contain a polyolefin resin. Examples of the polyolefin resin include polyethylene such as low-density polyethylene (LDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), and linear low-density polyethylene (LLDPE); polypropylene; ethylene-vinyl acetate copolymer, ionomer resin, ethylene-acrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene-methacrylic acid copolymer, and ethylene-propylene copolymer. The above polyolefin resins may be used alone or in combination of two or more. The density of LDPE and LLDPE is usually 0.900 to 0.930 g / cm 3 and the density of HDPE is typically 0.930 g / cm 3 Greater than 0.980g / cm 3 The following is the result.

[0057] The polyolefin resin may be a resin obtained using a raw material (monomer) obtained from fossil fuel or a resin obtained using a raw material (monomer) derived from biomass, but from the viewpoint of reducing the environmental load, a resin obtained using a raw material derived from biomass is preferable. Alternatively, the polyolefin resin may be a recycled resin. The recycled resin may be a mechanically recycled resin or a chemically recycled resin.

[0058] When the laser-beam-absorbing resin is polyamide and polyethylene is used as the polyolefin resin contained in the first resin layers 12, 13, and when the base layer 10 is obtained by co-extrusion, the polyethylene is preferably LLDPE. In this case, the difference in viscosity between the first resin layers 12, 13 and the second resin layer 11 is reduced, and curvature of either the first resin layers 12, 13 or the second resin layer 11 is suppressed in the base layer 10 obtained by co-extrusion.

[0059] The first resin layers 12, 13 may be formed by laminating multiple layers of the same type. The first resin layers 12, 13 may be formed of either a stretched or unstretched film. They may also be formed by laminating at least one stretched film and at least one unstretched film. The first resin layers 12, 13 can improve mechanical strength and dimensional stability by including a film that has been arbitrarily stretched in biaxial directions.

[0060] The first resin layers 12 and 13 may be made of the same polyolefin resin or different polyolefin resins.

[0061] The first resin layers 12 and 13 may contain at least one additive selected from the group consisting of a filler, an antistatic agent, a plasticizer, a lubricant, an antioxidant, and the like.

[0062] The thickness of the first resin layers 12, 13 is not particularly limited and may be, for example, 10 to 60 μm, but is preferably 10 to 30 μm, which can improve recyclability.

[0063] The thickness of the first resin layer 12 and the thickness of the first resin layer 13 may be the same or different from each other, but from the viewpoint of suppressing warping of the laminated film 100, it is preferable that the thickness of the first resin layer 13 is the same as the thickness of the first resin layer 12.

[0064] (adhesive layer) The adhesive layer 30 is a layer that functions to bond the base material layer 10 and the sealant layer 20. When the laminated film 100 has the adhesive layer 30, the adhesion between the base material layer 10 and the sealant layer 20 can be further improved, and peeling between the base material layer 10 and the sealant layer 20 can be more sufficiently suppressed.

[0065] The adhesive layer 30 is made of, for example, a polyolefin-based resin. Specific examples of such polyolefin-based resins include high-density polyethylene resin (HDPE), medium-density polyethylene resin (MDPE), LDPE, LLDPE, ethylene-methacrylic acid copolymer (EMAA), ethylene-acrylic acid copolymer (EAA), ionomer, polypropylene (PP), acid-modified polyethylene, and acid-modified polypropylene. When the polyolefin-based resin contains a resin other than polyethylene resin, it is desirable to limit the content of such resin to 10% by weight or less of the total polyolefin-based resin. To enhance adhesive strength, the surfaces of the base layer 10 and the sealant layer 20 may be subjected to corona treatment, ozone treatment, anchor coating, or the like. The thickness of the adhesive layer 30 is not particularly limited, but is preferably 2 μm or more and 50 μm or less. By making the thickness of the adhesive layer 30 2 μm or more, sufficient adhesive strength can be obtained.

[0066] The adhesive layer 30 may be an adhesive layer using an adhesive composition containing a dry laminating adhesive or the like, instead of a layer made of a polyolefin resin.

[0067] Dry lamination adhesives include known adhesives such as urethane adhesives, polyester adhesives, polyamide adhesives, epoxy adhesives, and isocyanate adhesives. Of these, urethane adhesives are preferred. In this case, effective adhesion is possible at low temperatures, and the raw materials are abundant, making it easy to design the adhesive and allowing easy adhesion to a variety of adherends, including plastics and metals.

[0068] The adhesive layer 30 may or may not contain a biomass component, but preferably contains a biomass component from the viewpoint of reducing the environmental impact. Specific examples of biomass components include the "DIC Dry BM Series" manufactured by DIC Corporation and the "ECOAD Series" manufactured by Toyo Ink Co., Ltd. The biomass component may be contained as a polyolefin resin or a component other than a polyolefin resin, or as an adhesive or a component other than an adhesive. Alternatively, the biomass component may be contained as a polyolefin resin or a component other than a polyolefin resin, or as an adhesive or a component other than an adhesive.

[0069] The adhesive composition may be an adhesive composition further containing an organic solvent, or an adhesive composition containing no organic solvent. From the viewpoint of reducing the environmental load, however, it is preferably an adhesive composition containing no organic solvent (solvent-free adhesive composition).

[0070] The thickness of the adhesive layer 30 is not particularly limited, but from the viewpoint of preventing peeling between the base layer 10 and the sealant layer 20 while preventing the laminated film 100 from becoming too thick, it is preferably 1 to 20 μm, and more preferably 2 to 15 μm.

[0071] (sealant layer) The sealant layer 20 contains a polyolefin resin. Examples of such polyolefin resins include polyethylenes such as low-density polyethylene (LDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), and linear low-density polyethylene (LLDPE); polypropylene; ethylene-vinyl acetate copolymers, ionomer resins, ethylene-acrylic acid copolymers, ethylene-methyl acrylate copolymers, ethylene-methacrylic acid copolymers, and ethylene-propylene copolymers. These may be used alone or in combination of two or more. However, when polyethylene is used as the polyolefin resin contained in the first resin layers 12 and 13 of the base layer 10, it is preferable that the polyolefin resin contained in the sealant layer 20 is also polyethylene, from the viewpoint of improving recyclability. When polyethylene is used as the polyolefin resin contained in the sealant layer 20, the density of the polyethylene is 0.890 to 0.930 g / cm 3 It is preferable that:

[0072] The polyolefin resin may be a resin obtained using a raw material (monomer) obtained from fossil fuel or a resin obtained using a raw material (monomer) derived from biomass, but from the viewpoint of reducing the environmental load, a resin obtained using a raw material derived from biomass is preferable. Alternatively, the polyolefin resin may be a recycled resin. The recycled resin may be a mechanically recycled resin or a chemically recycled resin.

[0073] The melting point of the polyolefin resin contained in the sealant layer 20 is preferably lower than the melting point of the polyolefin resin contained in the first resin layers 12, 13, from the viewpoint of suppressing melting of the first resin layers 12, 13 in the base material layer 10 during heat sealing of the laminated film 100. For example, when LLDPE is used as the polyolefin resin contained in the first resin layers 12, 13 in the base material layer 10, LDPE, which has a melting point lower than that of LLDPE, is used as the polyolefin resin contained in the sealant layer 20.

[0074] The sealant layer 20 can be formed by laminating a sheet containing, for example, a polyolefin resin to the adhesive layer 30 .

[0075] The thickness of the sealant layer 20 is not particularly limited and may be, for example, 20 μm or more or 50 μm or more, or 150 μm or less or 60 μm or less.

[0076] 2 is a cross-sectional view showing another embodiment of the laminate film of the present disclosure. As shown in FIG. 2, the laminate film 200 differs from the laminate film 100 in that it further includes a barrier layer 40 between the adhesive layer 30 and the base layer 10, and further includes a printed layer 50 between the adhesive layer 30 and the sealant layer 20.

[0077] In the laminate film 200, since the first resin layer 12 is provided between the barrier layer 40 and the second resin layer 11, even when the base layer 10 is irradiated with laser light, the influence of heat generated when the second resin layer 11 is burned away by the laser light can be sufficiently prevented from reaching the barrier layer 40. This can prevent damage to the barrier layer 40 and a decrease in the barrier properties of the barrier layer 40. Therefore, the laminate film 200 can sufficiently prevent oxygen, water vapor, and the like from penetrating into the packaging bag 400. This can prevent deterioration of the contents C.

[0078] Similarly, in the laminate film 200, since the first resin layer 12 is present between the printed layer 50 and the second resin layer 11, even if the base layer 10 is irradiated with laser light, the laser light can be sufficiently prevented from reaching the printed layer 50. Therefore, damage to the printed layer 50 can be suppressed.

[0079] The barrier layer 40 is a layer that has barrier properties against gases such as oxygen and water vapor. Examples of the barrier layer 40 include a vapor-deposited film made of an inorganic material, a metal foil, a resin film, and a resin film laminated with a vapor-deposited layer. Specific examples include inorganic vapor-deposited films such as silica, aluminum vapor-deposited films, aluminum foil, aluminum foil-laminated PET films, and various barrier films such as nylon-based barrier films and ethylene vinyl alcohol-based barrier films. The barrier layer 40 may include one of these materials alone or a combination of two or more of them.

[0080] The thickness of the barrier layer 40 is not particularly limited. When the barrier layer 40 is made of, for example, a vapor deposition layer, the thickness is, for example, 5 to 100 nm. When the barrier layer 40 is made of, for example, an aluminum foil, the thickness is, for example, 3 to 20 μm. In this way, the thickness is adjusted appropriately depending on the material of the barrier layer 40 and the application of the laminated film 200. The barrier layer 40 can be formed by, for example, a vacuum deposition method, a sputtering method, an ion plating method, a plasma vapor deposition method (CVD), a dry lamination method, an extrusion lamination method, or the like.

[0081] The printed layer 50 is a layer formed using ink made by adding various pigments, plasticizers, drying agents, stabilizers, etc. to a binder resin such as a urethane, acrylic, nitrocellulose, or rubber-based material. This printed layer can display letters, pictures, etc.

[0082] The ink may be either an aqueous ink or an oil-based ink, but is preferably an aqueous ink. An aqueous ink uses water or alcohol as a solvent, which can further reduce the environmental impact. In particular, when the adhesive composition is a solventless adhesive composition, using an aqueous ink as the ink can significantly reduce the environmental impact. Furthermore, the ink may or may not be a biomass ink, but from the perspective of reducing the environmental impact, a biomass ink is preferred. Here, biomass ink refers to an ink containing components obtained from biological resources (biomass), such as cotton, pulp, rice bran, vegetable oil, and angiosperm seeds.

[0083] Examples of printing methods that can be used include known printing methods such as offset printing, gravure printing, flexographic printing, silk screen printing, inkjet printing, etc. Furthermore, by subjecting the surface of the sealant layer 20 to a corona treatment or ozone treatment as a pretreatment, the adhesion of the printing layer 50 to the sealant layer 20 can be improved.

[0084] <Package> Next, an embodiment of the package of the present disclosure will be described with reference to Figures 3 and 4. Figure 3 is a front view showing one embodiment of the package of the present disclosure, and Figure 4 is a cross-sectional view taken along line IV-IV in Figure 3.

[0085] As shown in Figures 3 and 4, the packaging body 500 includes a packaging bag 400 and contents C contained in the packaging bag 400. The packaging bag 400 is formed using a pair of laminate films 100. Here, the sealant layer 20 of the laminate films 100 faces inward, and the base material layer 10 faces outward. The packaging bag 400 is composed of a storage section that stores the contents C, and an adhesive section 501 provided around the storage section. The adhesive section 501 is a section formed by bonding the sealant layers 20 of opposing laminate films 100 together, and the storage section is a section where the sealant layers 20 of opposing laminate films 100 are not bonded together.

[0086] According to the packaging body 500, the total content of polyolefin resin in the entire laminated film 100 constituting the packaging bag 400 is 90 mass % or more, so that the packaging body 500 can also maintain good recyclability.

[0087] Furthermore, according to the packaging body 500, in the laminate film 100 constituting the packaging bag 400, the base material layer 10 includes first resin layers 12 and 13 containing a polyolefin resin and a second resin layer 11 containing a laser-beam-absorbent resin layer. The laser-beam-absorbent resin contained in the second resin layer 11 absorbs the laser beam used to form the half-cut line, while the polyolefin resin contained in the sealant layer and the first resin layer does not absorb the laser beam. Therefore, when laser beams are irradiated onto the laminate film 100 from the base material layer 10 side of the packaging bag 400 to form the half-cut line, the laser beams reach the second resin layer 11 without passing through the sealant layer 20 and are therefore irradiated onto the second resin layer 11 with almost no attenuation. As a result, the laser-beam-absorbent resin absorbs the laser beams and is effectively burned away, effectively forming the half-cut line 510. Therefore, according to the packaging body 500, while maintaining good recyclability, after the half-cut line 510 is formed with a laser beam consisting of infrared light of a specific wavelength, tearability along the half-cut line 510 can be improved. Therefore, by tearing the packaging bag 400 along the half-cut line 510, the package 500 can be easily opened, and the contents C can be easily taken out.

[0088] Furthermore, according to the packaging body 500, in the packaging bag 400, the sealant layer 20 faces inward and the base material layer 10 including the second resin layer 11 faces outward, so that the half-cut line 510 can be easily formed from the base material layer 10 side.

[0089] (Contents) The contents C are not particularly limited and may be appropriately selected depending on the intended use of the packaging bag 400. Examples of the contents C include food, toiletry products such as shampoo, detergent, and bath additives, and cosmetics.

[0090] (packaging bag) The pair of laminated films 100 constituting the packaging bag 400 do not necessarily have to have the same layer structure, and may have different layer structures.

[0091] The packaging bag 400 may have an easy-open processed portion 520 (see FIG. 3) at both ends or one end of the half-cut line 510. Examples of the easy-open processed portion 520 include a group of scars, and a V-shaped, U-shaped, or I-shaped notch.

[0092] In the adhesive portion 501 of the packaging bag 400, the sealant layers 20 of the pair of laminated films 100 may be directly bonded to each other by heat fusion (see FIG. 3), or may be bonded to each other by an adhesive.

[0093] (Packaging manufacturing method) Next, a method for producing the packaging body 500 using the laminated film 100 will be described.

[0094] First, a pair of laminate films 100 are prepared. Then, a laminate is prepared by placing the sealant layers 20 of the pair of laminate films 100 opposite each other, and the sealant layers 20 are bonded together. At this time, parts of the peripheral edge of the laminate are bonded in a U-shape to form bonded parts 501, and also to form unbonded parts (unbonded parts). In this way, a packaging bag having unbonded parts is obtained.

[0095] Next, the contents C are filled into the packaging bag having an unbonded portion through the unbonded portion. Thereafter, the sealant layers 20 of the laminated film 100 are bonded together in the unbonded portion, thereby forming the unbonded portion into a bonded portion 501. In this manner, a package 500 including a packaging bag 400 and the contents C contained therein can be manufactured.

[0096] Although the preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments. For example, in the above embodiments, the base layer 10 includes the first resin layer 12, the second resin layer 11, and the first resin layer 13 in this order from the adhesive layer 30 side, but the first resin layer 12 or the first resin layer 13 may be omitted.

[0097] Furthermore, in the above-described embodiments, the laminated films 100, 200 are provided with the adhesive layer 30, but it is also possible to omit the adhesive layer 30 and directly bond the base material layer 10 and the sealant layer 20 together.

[0098] In addition, in the above embodiment, the laminated film 200 includes the printed layer 50, but the printed layer 50 may be omitted or may be provided between the barrier layer 40 and the adhesive layer 30, or between the barrier layer 40 and the base layer 10. Furthermore, the positions of the printed layer 50 and the barrier layer 40 may be interchanged.

[0099] In the above embodiment, the laminated film 200 includes the barrier layer 40, but a printed layer 50 may be provided instead of the barrier layer 40. Furthermore, when the base material layer 10 is formed by laminating the second resin layer 11, the first resin layer 13, and the first resin layer 12 in this order, the barrier layer 40 may be provided between the first resin layer 13 and the second resin layer 11, or between the first resin layer 12 and the second resin layer 11.

[0100] In the above embodiment, the shape of the packaging bag 400 is not limited to a four-sided bag as shown in Fig. 3, but may be a standing pouch-shaped packaging bag, a two-sided bag, a three-sided bag, a palm-shaped bag, or a gusset bag. The packaging bag 400 may be provided with a stopper or a synthetic resin zipper that can be repeatedly sealed by fitting a strip-shaped protrusion into a strip-shaped groove.

[0101] Furthermore, in the above embodiment, the packaging bag 400 is formed using a pair of laminate films 100, but the laminate film 200 may be used instead of the laminate film 100. Alternatively, a packaging bag may be manufactured by folding one laminate film 100, 200 with the sealant layer 20 facing inward and bonding the overlapping peripheral portions together. [Example]

[0102] The present disclosure will be described in more detail with reference to examples and comparative examples, but the present disclosure is not limited to the following examples.

[0103] Example 1 A co-extruded laminate film (manufactured by Tamapoly Co., Ltd., product name: ZPB102) having, in that order, a 15 μm thick first resin layer made of high-density polyethylene, a 10 μm thick second resin layer made of nylon, and a 15 μm thick first resin layer made of high-density polyethylene was prepared as a base layer.

[0104] Then, a urethane adhesive (manufactured by Mitsui Chemicals, Inc., product name: A626 / A50) was applied onto the first resin layer of the base material layer using a dry lamination machine, and a 100 μm thick LLDPE (density: 0.91 to 0.92 g / cm 3 A laminated film was produced by laminating a sealant layer consisting of a polyolefin resin (high density polyethylene and LLDPE) onto the laminated film. In this way, a laminated film having a laminated structure as shown in Figure 1 was produced. In the laminated film produced in this way, the total content of the polyolefin resins (high density polyethylene and LLDPE) was 92 mass%.

[0105] (Comparative Example 1) The base layer is a 30 μm thick film made of high-density polyethylene (density: 0.945 to 0.955 g / cm 3 A laminated film was produced in the same manner as in Example 1, except that the resin used was changed to a resin having a thickness of 100 μm, manufactured by Tamapoly Co., Ltd., trade name: HS31, and the second resin layer was not provided in the base material layer.

[0106] <Evaluation of tearability> Five sheets of each laminate film of Example 1 and Comparative Example 1 were prepared, and each of the five laminate films was irradiated with laser light from the base layer side of the laminate film along the MD direction (co-extrusion direction of the base layer) and TD direction at a scan speed of 1000 mm / min using a carbon dioxide laser (oscillation wavelength: 10600 nm, output: 25 W).

[0107] The laminated film was then torn along both the MD and TD directions, and the tear strength was measured in accordance with JIS K 7128. The results are shown in Table 1.

[0108] [Table 1] From the results shown in Table 1, in the laminated film of Example 1, even when half-cut lines were formed along the MD and TD directions and tearing was performed, the tear strength (average value) was 3.3 N (average value) in the MD direction and 6.0 N (average value) in the TD direction. On the other hand, in the laminated film of Comparative Example 1, even when an attempt was made to tear along the area irradiated with the laser light, the sealant layer and HDPE layer stretched, making it impossible to tear and measure the tear strength.

[0109] From the above, it was confirmed that the laminated film of the present disclosure can improve tearability along the half-cut line formed by laser light while maintaining good recyclability. [Explanation of symbols]

[0110] 100, 200... laminated film, 10... base material layer, 11... second resin layer, 12, 13... first resin layer, 20... sealant layer, 30... adhesive layer, 40... barrier layer, 50... printing layer, 400... packaging bag, 500... package, 510... half-cut line, C... contents.

Claims

1. a substrate layer; an adhesive layer using an adhesive composition containing an epoxy-based adhesive; a sealant layer containing a polyolefin resin in this order, a laminated film, wherein the substrate layer includes a first resin layer containing a polyolefin resin and a second resin layer containing a laser beam-absorbing resin, the base material layer has the first resin layer between the adhesive layer and the second resin layer, the laser beam-absorbing resin absorbs the laser beam used to form the half-cut line, and the polyolefin resin contained in the sealant layer and the first resin layer does not absorb the laser beam; A laminate film, wherein the total content of polyolefin resins in the entire laminate film is 90 mass % or more.

2. 2. The laminated film according to claim 1, wherein the laser-absorbent resin is at least one selected from the group consisting of polyethylene terephthalate, polyamide, and ethylene vinyl alcohol.

3. The laminated film according to claim 1 or 2, wherein the base layer comprises the second resin layer and two of the first resin layers arranged so as to sandwich the second resin layer.

4. a barrier layer between the substrate layer and the adhesive layer; The laminated film according to any one of claims 1 to 3, wherein the barrier layer is a vapor-deposited layer.

5. A packaging bag made using the laminated film according to any one of claims 1 to 4, wherein the sealant layer faces inward and the base material layer faces outward.

6. A package comprising the packaging bag according to claim 5 and contents accommodated in the packaging bag.

Images