Sealant film, laminate, packaging material, and packaging bag

Abstract

The sealant film (1a) is provided with a recycling material-containing layer (2) and a sealant layer (3) laminated on one main surface of the recycling material-containing layer, and the recycling material-containing layer (2) contains a recycling material containing two or more resins. The arithmetic surface roughness of the surface (S3a) of the sealant layer (3) on the opposite side from the recycled material-containing layer (2) side is 0.5 [mu] m or more and 5 [mu] m or less.

Description

TECHNICAL FIELD

[0001] The present application relates to a sealant film, a laminate, a packaging material, and a packaging bag. BACKGROUND

[0002] Plastic films are used for various substances because they have light weight, chemical stability, easy processability, flexibility, strength, and mass productivity. As their uses, for example, they are used in packaging materials for foodstuffs, pharmaceuticals, and the like, drip bags, shopping bags, posters, optical films, protective films, window films, plastic greenhouses, building materials, and the like. As specific materials, for example, thermoplastic resins such as polyethylene, polypropylene, polystyrene, polymethyl methacrylate, polycarbonate, polyamide, polyethylene terephthalate, polybutylene terephthalate, and the like, thermosetting resins such as epoxy resins, polyurethane, polyimide, and the like can be mentioned.

[0003] A laminate is also produced by selecting appropriate plastic materials according to the use and then stacking them. In addition, there is a method of compensating for the disadvantages of a single material by mixing a plurality of plastic materials in one layer.

[0004] As a countermeasure against environmental problems in recent years, recycling of plastic products is expected, and various recycling methods have been studied. For example, for plastic bottles, material recycling in which the recovered products are cleaned, crushed, and reused as raw materials, and chemical recycling in which monomers are produced have been established as technologies.

[0005] In addition, as material recycling of polyethylene, the use of recycled polyethylene for film and the like is being studied. For example, a sealant film containing recycled polyethylene resin is proposed in Patent Literature 1 below.

[0006] PRIOR ART DOCUMENTS PATENT LITERATURE Patent Literature 1: International Publication No. 2022 / 124229 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION There are also materials containing different types of resins in recycled materials. Therefore, the present inventors have studied the case where such recycled materials are recycled as raw materials for sealant films, and as a result, have found that the reliability at the time of heat sealing can sometimes be reduced in a sealant film provided with a layer containing a recycled material.

[0008] On the other hand, for a film product such as a sealant film, it is required to have a property (hereinafter also referred to as "film forming property") that enables forming processing without causing bending and wrinkling from the start of film forming to the stage of winding up. If the film forming property of the film is insufficient, appearance defects caused by bending and wrinkling are likely to occur in the film after winding up.

[0009] The present application was made in view of the above facts, and aims to provide a sealant film, a laminate, a packaging material, and a packaging bag, which contain a recycled material containing two or more kinds of resins, and which have sufficient reliability at heat sealing and film forming property.

[0010] Means for solving the problem In order to solve the above problem, the present inventors have studied the main cause of the decrease in reliability at heat sealing, and as a result, it has been found that if resins of different kinds are mixed in the layer containing the recycled material, a coagulum is formed from the resin component other than the resin having the largest content ratio, and if a too large protrusion is generated on the surface of the sealant film due to the coagulum, air is mixed in at heat sealing. Furthermore, based on this insight, the present inventors have further studied, and as a result, it has been found that a sealant film prepared in such a way that the surface roughness of the sealant layer reaches a specific condition is capable of solving the above problem, and thus the present application has been completed.

[0011] One aspect of the present application relates to the following [1] to

[15] .

[0012] [1] A sealant film comprising a recycled material-containing layer containing a recycled material containing two or more kinds of resins, and a sealant layer laminated on one main surface of the recycled material-containing layer, wherein the arithmetic surface roughness of the surface of the sealant layer opposite to the recycled material-containing layer side is 0.5 μm or more and 5 μm or less.

[0013] [2] The sealant film according to [1], wherein at least one of the recycled material-containing layer and the sealant layer contains a chemical recycled resin.

[0014] [3] The sealant film according to [1] or [2], wherein the sealant film contains a polyethylene-based resin derived from biomass.

[0015] [4] The sealant film according to any one of [1] to [3], wherein the sealant film has been subjected to electron beam irradiation treatment.

[0016] [5] The sealant film according to any one of [1] to [4], wherein the sealant film contains inorganic particles.

[0017] [6] The sealant film according to any one of [1] to [5], wherein the thickness of the sealant layer is 5 μm or more and 70 μm or less.

[0018] [7] The sealant film according to any one of [1] to [6], wherein the maximum height H of the convex portion on the surface of the sealant layer is 0.5 μm or more and 10 μm or less, and the ratio [W / H] of the width W at half the maximum height H of the convex portion having the maximum height H to the maximum height H is 20 or less.

[0019] [8] The sealant film according to any one of [1] to [7], wherein the resin having the largest content ratio among the two or more resins contained in the recycled material is a polyethylene-based resin or a polypropylene-based resin.

[0020] [9] The sealant film according to any one of [1] to [8], further comprising an auxiliary layer laminated on the other main surface of the recycled material-containing layer.

[0021]

[10] The sealant film according to [9], wherein the auxiliary layer contains a pure resin (virgin resin) of the same kind as the resin having the largest content ratio in the recycled material-containing layer.

[0022]

[11] A laminate comprising the sealant film according to any one of [1] to

[10] , and a gas barrier layer provided on the surface of the sealant film opposite to the side of the sealant layer.

[0023]

[12] A laminate comprising, in order, the sealant film according to any one of [1] to

[10] , an adhesive layer, and a base material film.

[0024]

[13] A packaging material comprising the sealant film according to any one of [1] to

[10] .

[0025]

[14] The packaging material according to

[13] , wherein the content of the plastic material contained in the recycled material is 10 mass% or more, based on the total amount of the plastic material in the packaging material.

[0026]

[15] A packaging bag made of the packaging material according to

[13] or

[14] .

[0027] Effects of Invention According to the present application, it is possible to provide a sealant film, a laminate, a packaging material, and a packaging bag, which contain a recycled material containing two or more resins and have sufficient reliability at heat sealing and film forming properties. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1is a schematic cross-sectional view showing one embodiment of the sealing agent film of the present application.

[0029] Figure 2 is a schematic view for explaining the aspect ratio of the low transmission luminance region.

[0030] Figure 3 is a schematic cross-sectional view showing another embodiment of the sealing agent film of the present application.

[0031] Figure 4 is a schematic cross-sectional view showing one embodiment of the laminate of the present application.

[0032] Figure 5 is a schematic cross-sectional view showing another embodiment of the laminate of the present application.

[0033] Figure 6 is a schematic cross-sectional view showing another embodiment of the laminate of the present application.

[0034] Figure 7 is a schematic cross-sectional view showing another embodiment of the laminate of the present application.

[0035] Figure 8 is a schematic cross-sectional view showing one embodiment of the packaging material of the present application.

[0036] Figure 9 is a schematic cross-sectional view showing another embodiment of the packaging material of the present application.

[0037] Figure 10 is a schematic cross-sectional view showing another embodiment of the packaging material of the present application. DETAILED DESCRIPTION

[0038] Hereinafter, embodiments of the present application will be described in detail. Furthermore, Figures 1-10 is a schematic view, which is shown schematically and appropriately exaggerated in size, shape, etc. of each part for easy understanding. In addition, the following embodiment examples illustrate the configuration for embodying the technical idea of the present application, and the technical idea of the present application is not limited to the materials, shapes, structures, etc. of the constituent parts described below. The technical idea of the present application can be variously changed within the technical scope defined by the claims recited in the claims.

[0039] <Sealing agent film> The sealing agent film of the present embodiment is provided with a recycling material-containing layer containing a recycling material including two or more kinds of resins and a sealing agent layer laminated on one main surface of the recycling material-containing layer.

[0040] Figure 1 is a schematic cross-sectional view showing one embodiment of the sealing agent film of the present application. Figure 1The sealant film 1a shown has a recyclable material layer 2 and a sealant layer 3 laminated on one of the main surfaces of the recyclable material layer 2.

[0041] At least one of the recyclable material layer and the sealant layer in this embodiment may contain a chemically recyclable resin.

[0042] Furthermore, due to increased awareness of preventing global warming and reducing the use of oil as a depleted resource, research is underway to replace traditional petroleum-derived plastics with plastics derived from carbon-neutral plants. Products containing at least 10% plant-derived plastics are certified as biomass by the Japan Organic Resources Association, and those containing at least 25% are certified as biomass plastics by the Japan Bioplastics Association. From the perspective of improving the biomass content of plastic-containing products such as packaging materials, there is a need for sealant films to contain plant-derived plastics.

[0043] The sealant film of this embodiment may contain a polyethylene-based resin derived from biomass. Such a sealant film, while containing recycled materials comprising two or more resins, exhibits sufficient reliability and film-forming properties during heat sealing, and can also improve the biomass content of plastic-containing products.

[0044] In addition, it is necessary to endow the sealant film with properties other than sealing. For example, by incorporating inorganic particles into the resin film, it is expected to impart concealing functions, and thus, based on such sealant films, the diversification of packaging materials can be pursued.

[0045] The sealant film of this embodiment may contain inorganic particles, either in a layer containing recycled material or in an auxiliary layer containing inorganic particles. Such a sealant film, while containing recycled material comprising two or more resins, possesses sufficient reliability and film-forming properties during heat sealing, and also imparts functionality due to the inorganic particles.

[0046] (Including a layer of recyclable materials) The recycled materials contained in the layer of recycled materials can include, for example, beverage / detergent / condiment bottles and bags that have been recycled from the market after being called post-consumer recycled materials (PCR), food containers for boxed meals or cup noodles, food / garbage bags, plastic products such as hangers / stationery / daily necessities / home appliances / toys, etc., or products that are not defective products that will not be exported from the factory, such as scraps generated during the product manufacturing process, plastic products used in transportation or packaging, etc.

[0047] In the case where the recycled material is a material-recycled material, the material-recycled material can be cleaned and crushed as needed. The material-recycled material has an advantage that less energy is required for recycling compared to a resin obtained by chemical recycling using chemical means such as thermal decomposition. Therefore, the larger the proportion of the material-recycled material in the material-recycled material-containing layer, the more the environmental load can be reduced.

[0048] In the sealant film of the present embodiment, from the viewpoint of material recycling of the plastic film, a sealant film made of a laminate (packaging material) in which a plurality of resin sheets are laminated, a packaging bag made by bagging the laminate, a laminate (packaging material) in which the same kind of resin sheets are laminated, or a packaging bag made by bagging the laminate, and a sealant film made by mixing them, and the like can be used. As the packaging bag, for example, a refill bag for toiletries and the like can be given.

[0049] The recycled material contained in the material-recycled material-containing layer contains two or more kinds of resins. As the two or more kinds of resins, thermoplastic resins, thermosetting resins, and cured products (including crosslinked products) thereof can be given. In addition, the two or more kinds of resins may, for example, also contain a resin component (for example, a thermosetting resin or the like) constituting an adhesive and a cured product thereof.

[0050] As the thermoplastic resins, polyolefin resins, acrylic resins, polycarbonate resins, polyester resins, polyamide resins, and the like can be given. As the thermosetting resins, epoxy resins, polyurethane resins, polyimide resins, and the like can be given.

[0051] As the polyolefin resins, for example, low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), polyethylene-based resins such as ethylene-α-olefin copolymers, and polypropylene-based resins such as homopolypropylene (PP), block polypropylene, random polypropylene, and propylene-α-olefin copolymers can be given.

[0052] As the polyester resins, for example, polyethylene terephthalate, polybutylene terephthalate, polylactic acid, and the like can be given.

[0053] As the polyamide resins, for example, nylon 6 and the like can be given.

[0054] The two or more kinds of resins can contain a first resin having the largest ratio among the recycled materials, and a second resin that is not compatible with the first resin or can form an aggregate in the first resin. The kind of the resin contained in the material-recycled material-containing layer can be confirmed by a micro infrared spectrophotometer or the like.

[0055] The first resin and the second resin can be the following combinations.

[0056] (a) thermoplastic resin and thermosetting resin and cured product thereof (b) hydrocarbon-based resin and heteroatom-containing resin (c) resin soluble in a prescribed solvent and resin insoluble in the prescribed solvent As the hydrocarbon-based resin in (b), a polyolefin-based resin, a polystyrene-based resin, or the like can be given, and as the heteroatom-containing resin, an acrylic resin, a polyester resin, a polyamide resin, or the like can be given.

[0057] As the prescribed solvent in (c), an aromatic hydrocarbon, a chlorinated hydrocarbon, or the like can be given. As the resin soluble in the prescribed solvent, an uncrosslinked resin, or the like can be given. As the resin insoluble in the prescribed solvent, a crosslinked resin, a cured thermosetting resin, or the like can be given.

[0058] As the first resin having the largest content ratio among the recycling material, from the viewpoint of recycling the packaging bag for a bag product or the like, a polyethylene-based resin or a polypropylene-based resin can also be given. In this case, as the second resin, at least one of a polyester resin, a polyamide resin, and a resin component constituting an adhesive and a cured product thereof, for example, can be given.

[0059] The content of the first resin in the recycling material-containing layer can be 75 to 98% by mass, 75 to 95% by mass, or 80 to 90% by mass, based on the total mass of the recycling material-containing layer.

[0060] The content of the second resin in the recycling material-containing layer can be 2 to 33 parts by mass, 5 to 33 parts by mass, or 11 to 25 parts by mass, relative to 100 parts by mass of the first resin.

[0061] The content of the recycling material in the recycling material-containing layer can be 13% by mass or more, 33% by mass or more, 50% by mass or more, or 100% by mass, based on the total mass of the recycling material-containing layer.

[0062] The resin having the largest content ratio in the recycling material-containing layer and the resin having the largest content ratio in the recycling material can be the same. As such a resin, at least one polyethylene-based resin selected from the group consisting of low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE), for example, can be given.

[0063] The layer containing recycled materials can also contain a pure resin or the like virgin material. The virgin material can be combined in such a manner that the resin having the largest content ratio in the layer containing recycled materials becomes the same as the resin having the largest content ratio in the recycled materials. As the virgin material, the same substance as the polyolefin resin described above can be used, or at least one polyethylene-based resin selected from the group consisting of low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE) can be used.

[0064] The pure resin can be a petroleum-derived resin or a biomass-derived resin, and from the viewpoint of increasing the biomass content, a biomass-derived resin is preferred.

[0065] The layer containing recycled materials can contain a biomass-derived polyethylene-based resin. By containing a biomass-derived polyethylene-based resin in the layer containing recycled materials, both the recycling rate and the biomass content can be taken into account, and the environmental load can be further reduced.

[0066] As the biomass-derived polyethylene-based resin, a homopolymer of plant-derived ethylene derived from bioethanol obtained from plant raw materials, and a copolymer of the plant-derived ethylene and another monomer can be mentioned.

[0067] The plant-derived ethylene can be obtained by fermenting a sugar solution or starch obtained from plants such as sugar cane, corn, sweet potato, and the like using microorganisms such as yeast, producing bioethanol by heating in the presence of a catalyst, and the like.

[0068] The plant-derived ethylene can also be obtained by fermenting a sugar solution or starch obtained from non-edible plants such as rice straw, sorghum, thinnings, waste mushroom beds, coffee grounds, and the like using microorganisms such as yeast, producing bioethanol by heating in the presence of a catalyst, and the like. By using non-edible plants as raw materials, competition with food resources is not generated, and thus a more sustainable and environmentally friendly film can be produced.

[0069] In addition, the biomass-derived polyethylene-based resin can use a commercially available substance (for example, Green PE, which is commercially available from Braskem Corporation, and the like).

[0070] In addition, the polyethylene-based resins having different densities and branching described above can be obtained by appropriately selecting the polymerization method. For example, a multi-site catalyst such as a Ziegler-Natta catalyst, a single-site catalyst such as a metallocene-based catalyst, or the like is preferably used as a polymerization catalyst, and the polymerization is performed in one stage or two or more stages by any one of gas phase polymerization, slurry polymerization, solution polymerization, and high-pressure ion polymerization.

[0071] The single-site catalyst described above refers to a catalyst capable of forming a uniform active species, and is usually prepared by contacting a metallocene-based transition metal compound, a non-metallocene-based transition metal compound, and an activating cocatalyst. The single-site catalyst is preferred because the active site structure is uniform compared to a multi-site catalyst, and thus a polymer having a high molecular weight and a high degree of uniformity can be polymerized. As the single-site catalyst, a metallocene-based catalyst is particularly preferred. The metallocene-based catalyst is a catalyst comprising a transition metal compound of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton, a cocatalyst, an organic metal compound used as necessary, and a carrier.

[0072] In the transition metal compound of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton described above, the cyclopentadienyl skeleton is a cyclopentadienyl group, a substituted cyclopentadienyl group, or the like. As the substituted cyclopentadienyl group, at least one substituent selected from a hydrocarbon group having 1 to 30 carbon atoms, a silyl group, a silyl-substituted alkyl group, a silyl-substituted aryl group, a cyano group, a cyanoalkyl group, a cyanoaryl group, a halogen group, a halogenated alkyl group, a halogenated silyl group, and the like is present. The substituted cyclopentadienyl group can have two or more substituents, and the substituents can be bonded to each other to form a ring, and can form an indenyl ring, a fluorenyl ring, an azulenyl ring, a hydrogenated product thereof, or the like. The ring formed by the bonding of the substituents to each other can further have substituents.

[0073] In the transition metal compound of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton, as the transition metal, zirconium, titanium, hafnium, and the like can be given, and zirconium and hafnium are particularly preferred. In the transition metal compound, two ligands having a cyclopentadienyl skeleton are usually present, and the ligands each having a cyclopentadienyl skeleton are preferably bonded to each other via a crosslinking group. As the crosslinking group, an alkylene group having 1 to 4 carbon atoms, a substituted silylalkylene group, a dialkylsilylalkylene group, a diarylsilylalkylene group, a substituted silylalkylene group, a dialkylgermylalkylene group, a diarylgermylalkylene group, a substituted germylalkylene group, and the like can be given, and a substituted silylalkylene group is preferred. The transition metal compound of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton described above can be used as a catalyst component alone or as a mixture of two or more kinds.

[0074] As a cocatalyst, it refers to a substance that enables the above-mentioned transition metal compound of Group IV of the periodic table to function as a polymerization catalyst or that enables the ionic charge balance after activation of the catalyst. As a cocatalyst, there are benzene-soluble aluminoxane of an organic aluminum oxide compound, benzene-insoluble organic aluminum oxide compounds, ion-exchangeable layered silicate, boron compounds, ionic compounds composed of a cation containing an active hydrogen group or not containing an active hydrogen group and a non-coordinating anion, lanthanum salts such as lanthanum oxide, tin oxide, phenoxy compounds containing a fluorine group, and the like.

[0075] The transition metal compound of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton can be used by being supported on a carrier of an inorganic or organic compound. As the carrier, a porous oxide of an inorganic or organic compound is preferable, and specifically, there are ion-exchangeable layered silicate such as montmorillonite, SiO2, Al2O3, MgO, ZrO2, TiO2, B2O3, CaO, ZnO, BaO, ThO2, or the like, or a mixture thereof. In addition, as an organic metal compound used further as needed, there are organic aluminum compounds, organic magnesium compounds, organic zinc compounds, and the like. Among them, an organic aluminum is preferably used.

[0076] In the case where the layer containing a recycled material contains a resin derived from biomass, it is easy to reduce Ra, H, and the ratio [W / H] of the sealant layer described later.

[0077] The layer containing a recycled material can also contain a chemically recycled resin. In the present specification, the chemically recycled resin refers to a resin obtained by chemical recycling, and refers to a resin produced by first low-molecularizing a waste resin through a process such as gasification or monomerization, and then polymerizing it. The chemically recycled resin is a new material produced from a raw material obtained by chemically decomposing waste, and thus can reduce foreign matter.

[0078] The chemically recycled resin can be used without particular limitation as long as it is a resin produced by a chemical recycling method. As the chemical recycling method, there are depolymerization, thermal decomposition, gasification, coke oven chemical raw materialization, blast furnace reducing agent method, and the like, and the method of polymerization or repolymerization is not particularly limited, and a publicly known method can be used.

[0079] The chemically recycled resin can also be a polyolefin resin such as a chemically recycled polyethylene and a chemically recycled polypropylene. Such a polyolefin resin can be produced, for example, by thermally decomposing mixed waste plastics containing a polyolefin resin under anaerobic conditions, cracking the obtained thermal decomposition oil (naphtha or the like) to generate ethylene and propylene, and polymerizing them.

[0080] In the case where the layer containing recycled materials contains a chemical recycled resin, it is easy to reduce Ra, H, and the ratio [W / H] of the sealant layer described later.

[0081] In the case where the layer containing recycled materials contains inorganic particles, the inorganic particles can be appropriately selected depending on the function to be imparted. As the function to be imparted, there can be mentioned hiding property, moisture absorption, and the like. The inorganic particles can be used singly or in combination of two or more.

[0082] In the case where the layer containing recycled materials is imparted with a hiding property, as the inorganic particles, white inorganic particles can be used, and from the viewpoint of the interfacial adhesion between the particle surface and the resin, there can be mentioned titanium oxide, zinc oxide, lithopone, calcium carbonate, barium sulfate, and aluminum hydroxide. Among them, from the viewpoint of not having a specific absorption in the visible region and having a high refractive index, titanium oxide is preferred.

[0083] From the viewpoint of dispersibility in the layer containing recycled materials, the average particle diameter of the inorganic particles can be 0.10 to 0.50 μm, 0.15 to 0.40 μm, or 0.20 to 0.30 μm. The average particle diameter of the inorganic particles refers to a value measured by a laser diffraction scattering method.

[0084] The content of the inorganic particles can be 0.10 to 30.00% by mass, based on the total mass of the layer containing recycled materials. In the case where the layer containing recycled materials is imparted with a hiding property, from the viewpoint of more excellent hiding property, the content of the inorganic particles can be 1.00% by mass or more, 5.00% by mass or more, 7.00% by mass or more, or 10.00% by mass or more, based on the total mass of the layer containing recycled materials. In addition, from the viewpoint of suppressing the decrease in cold impact resistance of the sealant film, the content of the inorganic particles can be 23.00% by mass or less, 20.00% by mass or less, 15.00% by mass or less, 12.00% by mass or less, or 8.00% by mass or less.

[0085] The inorganic particles are preferably dispersed in the layer containing recycled materials. In the case where the recycled material contains a resin having a polar group such as a hydroxyl group, an ester group, and an amide group, it is possible to optimize the dispersibility of the recycled material and the inorganic particles in the layer containing recycled materials.

[0086] In the case where the sealant film is imparted with a hiding property, inorganic particles can be contained in the layer containing recycled materials and / or the auxiliary layer described later, in a manner that the transmission density of the sealant film reaches 0.20 or more, 0.40 or more, or 0.50 or more. The transmission density can be measured using a portable transmission densitometer (Model 341C) of X-RITE Co.

[0087] The layer containing recycled material may, for example, contain agglomerates derived from the second resin or the like described above, but from the viewpoint of ensuring reliability at the time of heat sealing, the maximum diameter of the agglomerates can be 20 μm or less. When the maximum diameter of the agglomerates is 20 μm or less, it is easy to suppress the occurrence of protrusions having a height of 10 μm or more on the surface of the sealant layer or protrusions having a height of 0.5 μm to 10 μm and a ratio of the width at half the height to the height of 20 or more.

[0088] The layer containing recycled material can contain agglomerates having a maximum diameter of 40 μm to 100 μm, 50 μm to 90 μm, or 60 μm to 80 μm.

[0089] The agglomerates and the maximum diameter thereof can be confirmed by the following method.

[0090] The agglomerates contained in the layer containing recycled material can be confirmed as regions having a lower transmittance than the surrounding regions (hereinafter also referred to as "low transmittance regions") when performing transmittance observation from a direction in which the sealant film is observed in plan view, and the maximum diameter of the low transmittance regions can be obtained by the following steps.

[0091] (i) Using a stereoscopic microscope system SZX16 (manufactured by Olympus Corporation, product name), 10 observation images of the planar direction of the sealant film (image size: 243 μm x 851 μm) were randomly acquired.

[0092] (ii) The 10 images obtained were subjected to image analysis by WinROOF2021 (manufactured by San-Ei Gen F.F.I., Inc., product name). In the image analysis, the maximum diameter in each low transmittance region was calculated by binarizing the low transmittance regions and the high transmittance regions around them. In addition, in the binarization, the visual shape of the low transmittance regions can be made to coincide with the coloring range by appropriately combining the following operations.

[0093] (a) emphasizing the low transmittance regions by brightness and contrast adjustment (b) adjusting the threshold value so that the low transmittance regions visible coincide with the coloring range (c) in the case where a site having adjacent low transmittance regions is recognized as one region, a site where a low transmittance region of an opening is recognized as a plurality of regions, and the like, performing division and merging processing as necessary In order to reduce the maximum diameter of the agglomerates in the layer containing recycled material, for example, the following adjustment means can be mentioned.

[0094] (1) reducing the content ratio of the recycled material in the layer containing recycled material (2) increasing the content ratio of the first resin described above in the recycled material (3) Increasing the screw speed when extruding a layer containing recycled material. (4) When extruding a layer containing recycled material, try to avoid narrowing the flow path to form a structure that is difficult to apply tensile stress. (5) Recycled materials are granulated using a twin-screw extruder or mixed with pure resin to form a masterbatch for use. The thickness of the layer containing recycled materials can be 20~100μm.

[0095] (Sealant layer) The surface of the sealant layer opposite to the side containing the recycled material layer has an uneven shape, this surface (e.g.) Figure 1 S shown 3a The arithmetic surface roughness Ra of the sealant, as specified in JIS B 0601:2001, is 0.5 μm or more and 5 μm or less. If Ra is 5 μm or less, the reduction in reliability caused by air trapping (e.g., reduced low-temperature heat-sealing performance) can be suppressed during overlapping and heat-sealing of the sealant film. Furthermore, it is less likely to cause localized thinning of the recessed portion, leading to reduced impact resistance and puncture resistance. On the other hand, if Ra is 0.5 μm or more, the coefficient of friction will not become excessively high, providing moderate slippage and reducing the likelihood of wrinkles during film fabrication.

[0096] Based on the above viewpoints, Ra can be 0.5μm or more and 4μm or less, or 0.5μm or more and 3μm or less, or 0.5μm or more and 2μm or less, or 0.5μm or more and 1.5μm or less, or 1.0μm or more and 4μm or less, or 1.0μm or more and 3μm or less, or 1.0μm or more and 2μm or less.

[0097] In addition to adjusting the maximum diameter of the aggregate as described above, other methods for adjusting Ra include changing the thickness of the sealant layer, adding an anti-blocking agent to the sealant layer, and giving the surface of the sealant layer a specified texture (e.g., pressing the clamping roller when cooling and curing the molten resin during film making).

[0098] From the perspective of ensuring reliability during heat sealing, the aforementioned surface of the sealant layer ( Figure 2 S shown 3a ) in the convex part ( Figure 2 P shown 3a ) height ( Figure 2 H shown 3a The thickness can be less than 10μm, or it can be 0.5~9μm, or it can be 0.5~8μm. Furthermore, from the same perspective, the width at half the height of the convex part ( Figure 2 The W shown3a ) can be 200 μm or less, can be 1 to 150 μm, or can be 1 to 100 μm. In addition, Figure 2 is a schematic cross-sectional view for illustrating the shape of the convex portion in the sealant film. Figure 1 As shown in FIG. 2, the convex portion P Figure 2 3a The surface S of the sealant layer 3 is sometimes raised due to the agglomerate 50 generated in the layer containing recycled materials. 3a

[0099] The convex portion on the surface of the sealant layer can be a convex portion having a maximum height H of 0.5 μm or more and 10 μm or less, and a ratio [W / H] of a width W at half the maximum height H to the maximum height H of 20 or less, or can be a convex portion having the above H of 0.5 to 9 μm and a ratio [W / H] of 1 to 18. In this case, it is advantageous in terms of, for example, (1) an increase in the content of recycled materials in the layer containing recycled materials, (2) an increase in the content of recycled materials in the sealant film due to the thinning of the sealant layer, and (3) an increase in productivity due to a reduction in the pressure applied during cooling or heat pressing during film formation.

[0100] As a material forming the sealant layer, a material having moderate flexibility and having good processability, for example, processability using an extruder, can be used. As such a material, for example, low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), and polypropylene having a homopolymer, a random copolymer, a block copolymer, an ethylene-vinyl acetate copolymer obtained by copolymerizing an olefin such as low-density polyethylene (LDPE) with vinyl acetate, an ethylene-methyl acrylate copolymer (EMA) obtained by modifying the side chain of an olefin, an ethylene-ethyl acrylate copolymer (EEA), an ethylene-butyl acrylate copolymer (EBA), and an ethylene-methacrylic acid copolymer (EMAA) can be given. One of them can be used alone, or two or more of them can be used in combination.

[0101] The resin forming the sealant layer can be a chemical recycled resin. The chemical recycled resin can use the above-described resin.

[0102] From the viewpoint of reducing environmental load, the content of the chemical recycled resin in the sealant layer is preferably 40% by mass or more, further preferably 70% by mass or more, further more preferably 90% by mass or more, and particularly preferably 100% by mass, based on the total mass of the sealant layer.

[0103] ​​As the resin forming the sealant layer, a biomass-derived polyethylene-based resin can be included. The biomass-derived polyethylene-based resin can use the resin described above.

[0104] The biomass degree of the biomass-derived polyethylene-based resin in the sealant layer is preferably 50% or more and 100% or less, and more preferably 70% or more and 100% or less. Thereby, the biomass degree in the sealant film can be increased, and the environmental load can be further reduced. Note that the biomass degree refers to the dry weight ratio of the biomass raw material used.

[0105] From the viewpoint of heat sealability, the sealant layer can include the same kind of resin as the resin having the largest inclusion ratio in the inclusion recycled material layer, or can include a pure resin and / or a chemically recycled resin in a manner so as to include the same kind of resin as the resin having the largest inclusion ratio in the inclusion recycled material layer. For example, in the case where the resin having the largest inclusion ratio in the inclusion recycled material layer is a polyethylene-based resin, the sealant layer can include a polyethylene-based resin, or a polyethylene-based resin can be the main component (for example, the inclusion ratio in the sealant layer is 95% by mass or more). In this case, at least one of the inclusion recycled material layer and the sealant layer, or at least one of the inclusion recycled material layer, the sealant layer, and the auxiliary layer described later can include a biomass-derived polyethylene-based resin. In addition, in the case where the resin having the largest inclusion ratio in the inclusion recycled material layer is a polypropylene-based resin, the sealant layer can include a polypropylene-based resin, or a polypropylene-based resin can be the main component (for example, the inclusion ratio in the sealant layer is 95% by mass or more).

[0106] From the viewpoint of reducing the maximum height H and the ratio [W / H] described above, the sealant layer can include a polypropylene-based resin.

[0107] From the viewpoint of film production processability of the film, the MFR of the polyethylene-based resin can be 0.05 to 15 g / 10 minutes, or can be 0.1 to 8 g / 10 minutes. The MFR here refers to a value measured in accordance with JIS K 7210 (190°C, load 2.16 kg).

[0108] From the viewpoint of film production processability of the film, the MFR of the polypropylene-based resin can be 0.05 to 20 g / 10 minutes, or can be 0.1 to 10 g / 10 minutes. The MFR here refers to a value measured in accordance with JIS K 7210 (230°C, load 2.16 kg).

[0109] From the viewpoint of heat sealability and rigidity, the crystallinity of the polypropylene-based resin based on the heat of fusion using a differential scanning calorimeter (DSC) can be 25% or more and 60% or less, or can be 30% or more and 55% or less.

[0110] In the present specification, the crystallinity of the polypropylene-based resin is calculated from the ratio of the heat of fusion ΔHm calculated from the integral of the endothermic peak upon melting of the test sample to the heat of fusion ΔH100 of a perfect crystal having a crystallinity of 100% calculated from theory, as in the following equation, to calculate the crystallinity of the test sample.

[0111] Crystallinity [%] = (ΔHm / ΔH100) x 100 Further, the heat of fusion ΔH100 of a perfect crystal can adopt the value described in the following document. For example, ΔH100 of polypropylene can be 207 J / g. Reference: (Gakkai) Plastic Shaping Processing Society: Plastic Materials in Shaping Processing, 335 (2011), Morikita Publishing Co., Ltd. The sealant layer can contain the above-described resin as a virgin material. Alternatively, from the viewpoint of stability of heat-sealability, the sealant layer can not contain recycled materials.

[0112] The thickness of the sealant layer can be 5 μm or more and 70 μm or less. In this case, it is easy to prevent exposure of the agglomerates contained in the recycled material-containing layer from the sealant layer, and it is easy to ensure the rigidity of the entire sealant film and to increase the proportion of the recycled material contained in the sealant film. Thus, in the sealant film, material recycling of the recycled material containing two or more kinds of resins can be more effectively achieved. The thickness of the sealant layer can also be 5 μm or more and 60 μm or less, 5 μm or more and 55 μm or less, 5 μm or more and 50 μm or less, 5 μm or more and 40 μm or less, 5 μm or more and 30 μm or less, 5 μm or more and 20 μm or less, 10 μm or more and 65 μm or less, 10 μm or more and 60 μm or less, 10 μm or more and 55 μm or less, 10 μm or more and 50 μm or less, 10 μm or more and 40 μm or less, 10 μm or more and 30 μm or less, 15 μm or more and 60 μm or less, or 20 μm or more and 60 μm or less.

[0113] In the recycled material-containing layer and the sealant layer, a compatibilizer, a nucleating agent, a reinforcing filler, an antioxidant, a heat stabilizer, a weathering agent, a light stabilizer, a plasticizer, an ultraviolet absorber, an antistatic agent, a flame retardant, a flame retardant aid, a slip agent, an antiblocking agent, an antifog agent, a lubricant, a pigment, a dye, a dispersant, a copper inhibitor, a neutralizing agent, a bubble preventing agent, a welding strength improver, a natural oil, a synthetic oil, a wax, or the like can be added as needed. The additive can be used alone or in combination with two or more kinds.

[0114] As the nucleating agent and the reinforcing filler, talc, silica, clay, montmorillonite, calcium carbonate, lithium carbonate, alumina, titanium oxide, metals such as aluminum, iron, silver, and copper, hydroxides such as aluminum hydroxide and magnesium hydroxide, cellulose microfibrils, cellulose-based materials such as cellulose acetate, glass fibers, polyethylene terephthalate fibers, nylon fibers, polyethylene naphthalate fibers, aramid fibers, vinylon fibers, polyacrylate fibers, carbon-based materials such as carbon nanotubes, elastomers such as ethylene-propylene rubber (EPR), and the like can be given.

[0115] As the antioxidant, a phenol-based compound, an organic phosphite-based compound, a sulfide-based compound, and the like can be given.

[0116] As the heat stabilizer and the light stabilizer, a hindered amine-based compound and the like can be given.

[0117] As the ultraviolet absorber, a benzophenone-based compound, a benzotriazole-based compound, a benzoate-based compound, and the like can be given.

[0118] As the antistatic agent, a nonionic compound, a cationic compound, an anionic compound, and the like can be given.

[0119] As the flame retardant, a halogen-based compound, a phosphorus-based compound, a nitrogen-based compound, an inorganic compound, a boron-based compound, a silicone-based compound, a sulfur-based compound, a red phosphorus-based compound, and the like can be given.

[0120] As the flame retardant aid, an antimony compound, a zinc compound, a bismuth compound, magnesium hydroxide, clay silicate, and the like can be given.

[0121] As the antiblocking agent, acrylic particles, styrene particles, styrene acrylic particles and crosslinked products thereof, polyurethane-based particles, polyester-based particles, silicon-based particles, fluorine-based particles, copolymers thereof, zeolite, pyrophyllite, talc, montmorillonite, vermiculite, mica, chlorite, kaolin minerals, sepiolite, clay compounds such as clay, silica, titanium oxide, aluminum oxide, silica-aluminum oxide, zirconium oxide, zinc oxide, strontium oxide, aluminum hydroxide, strontium carbonate, strontium chloride, strontium sulfate, strontium nitrate, strontium hydroxide, glass particles, and the like can be given.

[0122] In the sealant film of the present embodiment, the ratio Tr / Ts of the thickness Tr of the recycling material-containing layer to the thickness Ts of the sealant layer can be 0.3 to 16, and can also be 0.5 to 14, and can also be 0.7 to 12.

[0123] The sealant film of the present embodiment is subjected to electron beam irradiation treatment. Thereby, the crosslinking density of the resin contained in the sealant film is increased by electron beam irradiation, and the mechanical strength of the sealant film can be further optimized.

[0124] Packaging bags such as bags are generally produced by bag-making from packaging materials provided with a sealant film, but if a pinhole is generated in the packaging material constituting the packaging bag due to friction or the like during conveyance, external gas or components of the base material layer can intrude into the packaging bag, which can possibly affect the hygiene of the contents. In addition, in the case of filling contents having an acute angle portion, a pinhole can possibly be generated from the inside to the outside of the packaging bag. Therefore, the sealant film used for the packaging material is preferably excellent in puncture strength. The sealant film of the present embodiment can have sufficient reliability at the time of heat sealing, puncture strength, and film-forming property while containing a recycled material containing two or more resins, when subjected to electron beam irradiation treatment.

[0125] The electron beam irradiation treatment can be performed from the side opposite to the side on which the sealant layer is provided (the side opposite to the side in contact with the contents or the filler in the packaging material provided with the sealant film) of the sealant film.

[0126] In addition, the sealant film of the present embodiment can be subjected to electron beam irradiation treatment after being formed into the laminated body or the packaging material described later. For example, an ink layer or a top coat layer that is cured by electron beam irradiation can be provided on the sealant film, and the irradiation conditions of the electron beam can be set in such a manner that the sealant film is irradiated with a prescribed amount of electron beam. In particular, in the case of multi-color printing, the strength can be expected to be further improved by cumulatively irradiating each color with EB. In addition, in the case of a packaging material in which the sealant film is laminated with a gas barrier layer, a base material film, or the like, the irradiation conditions of the electron beam can be set in such a manner that the sealant film is irradiated with a prescribed amount of electron beam in EB sterilization performed after the bag is produced and the contents are filled. From the viewpoint of improving the puncture strength and the like, it is preferable to adjust the acceleration voltage and the irradiation energy of the electron beam in such a manner that the amount of the electron beam in the sealant film is 10 KGy or more and 2000 KGy or less, or 20 KGy or more and 500 KGy or less. From the same viewpoint, the amount of the electron beam and the acceleration voltage and the irradiation energy of the electron beam can be adjusted in such a manner that the gel fraction of the sealant film reaches a range described later.

[0127] The gel fraction of the sealant film of the present embodiment calculated by the following method can be 0.5% or more and 85% or less, or 20% or more and 80% or less. The gel fraction can be an index of the cross-linking density, and when the gel fraction is in the above range, it is easy to balance the improvement in the mechanical strength of the sealant film by increasing the cross-linking density of the layer containing the recycled material and the assurance of the heat sealability by not excessively cross-linking the sealant layer.

[0128] (Method for calculating gel fraction) The gel fraction is a calculation method that takes advantage of the fact that the crosslinked portion does not dissolve in a solvent, and can be calculated by immersing the sealant film in an organic solvent such as xylene, drying the insoluble film remaining after the non-dissolved portion, and measuring the mass, from the mass of the sealant film before dissolution and the mass of the dried insoluble film. Specifically, the gel fraction can be calculated by the following steps.

[0129] (i) First, the sealant film Xg is wrapped with a stainless steel mesh of Yg, and immersed by heating in a solvent. The heating temperature and the immersion time are 120°C and 8 hours, respectively.

[0130] (ii) Next, the sealant film wrapped with the stainless steel mesh is taken out of the solvent, and vacuum-dried. The drying temperature and the drying time are 60°C and 3 hours, respectively.

[0131] (iii) The mass of the sealant film wrapped with the stainless steel mesh after drying (Zg) is measured, and the gel fraction is calculated from the following formula (1).

[0132] Gel fraction (% by mass) = [(Z - Y) / X] x 100 (1) Further, even if the amount of radiation by EB irradiation is low, there are cases where the physical strength is improved by EB irradiation, and even if the gel fraction is increased by a small amount, it is presumed that crosslinking has occurred. In such cases, in DSC (differential scanning calorimeter) analysis, a phenomenon in which the melting peak intensity shifts to a lower temperature and the melting enthalpy is observed.

[0133] The sealant film of the present embodiment can also be a multilayer structure that is completed by further laminating other layers to complement the desired properties. Figure 3 is a schematic cross-sectional view that shows another embodiment of a sealant film. Figure 3 The sealant film 1b shown has a recycled material-containing layer 2, a sealant layer 3 laminated on one main surface of the recycled material-containing layer 2, and an auxiliary layer 4 laminated on the other main surface of the recycled material-containing layer 2. In this case, the surface S 3b of the sealant layer 3 on the side opposite the recycled material-containing layer 2 side is also able to satisfy the above conditions.

[0134] In order to further improve the rigidity of the sealant film 1b, the auxiliary layer 4 can be composed of a resin having a high density, and in order to suppress curling due to thermal shrinkage of the sealant film 1b, the auxiliary layer 4 can be composed of a resin having a density that is the same degree as the resin that constitutes the sealant layer 3 (for example, a density difference of 0.1 kg / m 3 The following).

[0135] Further, when the auxiliary layer 4 has a function as a lamination layer, the auxiliary layer 4 can have the same configuration as the above-described sealant layer 3. From the viewpoint of reducing environmental load, the auxiliary layer 4 can contain a chemically recycled resin. From the viewpoint of improving the biobased content, the auxiliary layer 4 can contain a polyethylene-based resin derived from biomass. Further, the auxiliary layer 4 can contain the same kind of resin as the resin having the largest content ratio in the recycled material-containing layer 2. In this case, the adhesion to other layers is easily improved by higher lamination strength.

[0136] One or two or more of the above-described additives can be incorporated in the auxiliary layer 4 as needed.

[0137] Further, when the auxiliary layer 4 has a function as a lamination layer, the arithmetic surface roughness Ra of the surface of the auxiliary layer 4 on the side opposite to the recycled material-containing layer 2 side, which is defined by JIS B 0601:2001, can be 0.03 μm or more and 5 μm or less, can be 0.04 μm or more and 3 μm or less, or can be 0.05 μm or more and 2 μm or less. In this case, when other layers are stacked on the lamination layer via an adhesive layer, lamination failure due to the occurrence of a defective portion where the adhesive does not adhere is easily suppressed.

[0138] The above-described Ra of the auxiliary layer 4 can be adjusted by changing the thickness of the auxiliary layer. From the viewpoints of suppressing lamination failure and suppressing cost, the thickness of the auxiliary layer in this case can be 5 μm or more and 100 μm or less, can be 10 μm or more and 90 μm or less, or can be 20 μm or more and 80 μm or less.

[0139] From the viewpoint of reducing environmental load, the sealant film of the present embodiment can not contain a pure resin derived from petroleum. For example, in the case of the sealant film 1a shown in FIG. 1, the recycled material-containing layer 2 and the sealant layer 3 can not contain a pure resin derived from petroleum, and in the case of the sealant film 1b shown in FIG. 2, the recycled material-containing layer 2, the sealant layer 3, and the auxiliary layer 4 can not contain a pure resin derived from petroleum. Figure 1 Figure 3

[0140] In the sealant film 1b, the electron beam irradiation treatment can be performed from the side opposite to the side on which the sealant layer is provided (the auxiliary layer side) (the side opposite to the side in contact with the content or the filler in the packaging material provided with the sealant film). The sealant film 1b can have the above-described gel fraction.

[0141] <Method for manufacturing a sealant film> ​​The sealant film of the present embodiment can be manufactured by a method known in the art. For example, a method of extrusion-laminating a recycled material-containing film made of a resin composition constituting the recycled material-containing layer with a resin composition constituting the sealant layer, or a method of film- forming the recycled material-containing layer and the sealant layer by co-extrusion molding can be used.

[0142] In the former method, the recycled material-containing film can be film-formed by a T-die using a feed block or a multi-channel after melting the resin composition constituting the recycled material-containing layer with an injection molding machine or an extrusion molding machine (e.g., a twin-screw extruder), or by a blow molding method. The recycled material can be a material made into pellets by melting and molding an extruder after recycling, cleaning, and pulverizing various plastic waste. The extrusion lamination can use an extrusion laminator or the like.

[0143] In the latter method, for example, a multi-layer extrusion molding machine can be used to melt and knead the resin composition constituting the recycled material-containing layer and the resin composition constituting the sealant layer separately and co-extrude them, thereby producing the sealant film.

[0144] The resin composition constituting the recycled material-containing layer can contain only the recycled material, or can further incorporate a pure resin, an additive, or the like in order to impart various desired properties such as viscosity adjustment, mechanical property enhancement, and the like. In the case of mixing the recycled material and the pure resin, dry blending in which the pure resin and the recycled material are simultaneously fed into a hopper while being melt-kneaded to form a film, or melt blending in which the pure material and the recycled material are separately melt-kneaded by a twin-screw extruder to form a master batch can be used.

[0145] From the viewpoint of reducing the agglomerates in the recycled material-containing layer, re-pelletization using a twin-screw extruder, molding under high shear conditions, or incorporation of an acid-modified polyolefin resin or the like as a compatibilizer can be performed.

[0146] Regarding the cooling method of the film, an air cooling method such as an air cavity, a vacuum cavity, an air knife, or the like, a water cooling method such as immersion of a cooling roll in a cold water tank, or the like can be used depending on the molding machine used.

[0147] Further, for example, in the case of a T-die method, in order to adjust the above-mentioned Ra of the sealant layer, a prescribed surface shape can also be imparted to the sealant layer by pressing with a nip roller when cooling and solidifying the molten resin using a cooling roller having a prescribed surface shape. As a means for imparting a surface shape by molding, it can be a method in which the molten resin is caused to flow into a contact portion of a nip roller and a cooling roller to which a pressure of 0.1 MPa or more is applied, and is cooled. The cooling roller can be a cooling roller obtained by cutting processing a metal, or a cooling roller imparted with a shape by sandblasting processing. The surface shape of the cooling roller can be a random concavo-convex shape, and the surface roughness can be adjusted by changing the particle size, processing time (amount) at the time of sandblasting processing. Further, the above-mentioned Ra of the auxiliary layer can also be adjusted in the same manner as described above.

[0148] Further, the sealant film of the present embodiment can also be produced by a method utilizing heat pressing. In the method utilizing heat pressing, a flat film can be shaped by being compressed between heating rollers or with a heated flat plate. By adjusting the pressure at which compression is performed at this time, the thickness of the shaped product can be controlled. The single layer film produced by heat pressing can be overlapped and heat pressed again to be layered, or a flat film that has been layered in advance can be prepared and the film thickness can be adjusted by heat pressing. Further, as adjustment of the surface roughness, in the case of imparting a prescribed surface shape to the film, the surface of the roller or flat plate can be imparted with a prescribed surface shape and then transferred. The surface shape can be a random concavo-convex shape, and the surface roughness can be adjusted by changing the particle size, processing time (amount) at the time of sandblasting processing.

[0149] In the present embodiment, the above-mentioned produced sealant film can be subjected to electron beam irradiation processing. By electron beam irradiation, the cross-linking density of the resin contained in the sealant film is increased, and the mechanical strength (particularly, the puncture strength) of the sealant film can be optimized. The electron beam irradiation processing is preferably performed from the side of the sealant film opposite to the side on which the sealant layer is provided (the side opposite to the side that contacts the contents or the filler in the packaging material provided with the sealant film).

[0150] Further, the above-mentioned produced sealant film satisfies the above-mentioned condition with respect to the arithmetic surface roughness of the surface of the side of the sealant layer opposite to the side of the layer containing recycled materials, and thus the mechanical strength (particularly, the puncture strength) is easily increased by electron beam irradiation processing. Furthermore, by the above-mentioned method, the maximum height H of the convex portion on the above-mentioned surface of the sealant layer, the ratio [W / H] satisfy the above-mentioned conditions, and thus the mechanical strength (particularly, the puncture strength) is easily increased by electron beam irradiation processing.

[0151] As the device capable of irradiating the electron rays to the sealant film, a device of a low energy type conventionally known is preferably used, and for example, a curtain type electron irradiation device (LB1023, manufactured by I-Electron Co., Ltd.), a line irradiation type low energy electron ray irradiation device (EB-ENGINE, manufactured by Hamamatsu Photonics Co., Ltd.), and a drum roller type electron ray irradiation device (EZ-CURE, manufactured by I-Electron Co., Ltd.), and the like can be mentioned.

[0152] The amount of the electron rays and the acceleration voltage of the electron rays irradiated to the sealant film can be appropriately set, and can be appropriately adjusted in a range where the electron rays do not reach the sealant layer when the electron rays are irradiated to the main surface of the sealant film on the side opposite to the sealant layer side. In this case, the crosslinking density of the sealant layer is increased by the electron rays, and the heat sealability of the sealant layer can be suppressed from being decreased. In addition, the amount of the electron rays and the acceleration voltage of the electron rays and the irradiation energy can also be adjusted in such a manner that the gel fraction of the sealant film reaches the above range.

[0153] The amount of the electron rays can be 10 kGy or more and 2000 kGy or less, and can also be 20 kGy or more and 500 kGy or less.

[0154] The acceleration voltage of the electron rays can be 30 kV or more and 300 kV or less, and can also be 50 kV or more and 300 kV or less, and can also be 50 kV or more and 250 kV or less.

[0155] The irradiation energy of the electron rays can be 20 keV or more and 750 keV or less, and can also be 25 keV or more and 500 keV or less, and can also be 30 keV or more and 400 keV or less, and can also be 20 keV or more and 200 keV or less.

[0156] The oxygen concentration in the electron ray irradiation device can be 500 ppm or less, and can also be 100 ppm or less. By performing the electron ray irradiation under such conditions, the generation of ozone can be suppressed, and the inactivation of the radicals generated due to the electron ray irradiation by the oxygen in the environmental gas can be suppressed. Such conditions can be achieved, for example, by setting the inside of the device to an inert gas (nitrogen, argon, or the like) environmental gas.

[0157] The surface modification treatment for improving the post-process adaptability can be performed to the sealant film. For example, in order to improve the printability and improve the laminating adaptability when layered with other layers or a base material film, the surface modification treatment can be performed to the surface to be laminated. As the surface modification treatment, a method of making a functional group appear by oxidizing the film surface, such as a corona discharge treatment, a plasma treatment, a flame treatment, and the like, a modification using a wet process, such as the coating of an easy-adhesion layer, can be mentioned.

[0158] Further, the method of producing the sealant film is not limited to the above-described method, and the sealant film produced using the forming machine can be subjected to a stretching treatment on-line or off-line. Further, the addition of necessary processes and additives is not limited.

[0159] <laminate> The laminate of the present embodiment is provided with the sealant film of the present embodiment described above.

[0160] The laminate can be provided with the sealant film of the present embodiment and a gas barrier layer provided on the surface of the sealant film on the side opposite to the sealant layer side, for example.

[0161] In the case where the film is used as a food packaging material, a film having gas barrier properties is required. The above-described laminate has sufficient reliability at the time of heat sealing and film forming while containing a recycled material containing two or more kinds of resins, and is also excellent in gas barrier properties.

[0162] Figure 4 is a schematic cross-sectional view showing one embodiment of the laminate of the present embodiment. Figure 4 The laminate 10a shown is provided with a sealant film 1a in which a recycled material-containing layer 2 and a sealant layer 3 are laminated, and a gas barrier layer 12 provided on the recycled material-containing layer 2 of the sealant film 1a. Figure 5 is a schematic cross-sectional view showing another embodiment of the laminate of the present embodiment. Figure 5 The laminate 10b shown is a laminate in which a gas barrier layer 12 is provided on the surface of the sealant film 1b on the side opposite to the recycled material-containing layer 2 side. Figure 3 The side of the auxiliary layer 4 in the sealant film 1b shown is further provided with a gas barrier layer 12 on the side opposite to the recycled material-containing layer 2 side. The laminate 10a and the laminate 10b can be laminates in which the gas barrier properties (for example, oxygen barrier properties and water vapor barrier properties, etc.) are improved. The gas barrier layer can be a single-layer structure or a laminated structure.

[0163] The laminate of the present embodiment can improve the denseness of the gas barrier layer (particularly, the vapor-deposited layer) formed by providing the gas barrier layer and smoothing the surface of the sealant film (in the present embodiment, the surface of the recycled material-containing layer), and the gas barrier properties can be made good.

[0164] The gas barrier layer can be formed on the surface of the sealant film obtained above on the side opposite to the sealant layer side (for example, the surface of the recycled material-containing layer, the surface of the auxiliary layer) using a publicly known method.

[0165] As the gas barrier layer 12, a vapor-deposited layer (vapor-deposited film) composed of a metal or an inorganic oxide, etc., a metal foil such as an aluminum foil, and a film of an ethylene-vinyl alcohol copolymer, a polyamide-based resin, a polyvinylidene chloride-based resin, a polyacrylonitrile-based resin, etc. can be mentioned.

[0166] The vapor deposition layer can be a single layer structure or a stacked layer structure. As the vapor deposition layer, a vapor deposition layer composed of a metal such as aluminum, and an inorganic oxide such as aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, hafnium oxide, and barium oxide can be given.

[0167] The vapor deposition layer can be formed using a publicly known method. The formation method can be appropriately selected from, for example, a physical vapor deposition method (Physical Vapor Deposition method, PVD method) such as a vacuum evaporation method, a sputtering method, and an ion plating method, and a chemical vapor deposition method (Chemical Vapor Deposition method, CVD method) such as a plasma chemical vapor deposition method, a thermal chemical vapor deposition method, and a photochemical vapor deposition method, in accordance with the vapor deposition material, and the like.

[0168] In the case where the vapor deposition layer is an aluminum vapor deposition film, the OD value thereof can be 2 or more and 3.5 or less from the viewpoint of productivity, oxygen barrier property, and water vapor barrier property of the laminate. In addition, in the present specification, the OD value refers to a value measured in accordance with JIS-K-7361.

[0169] In the case where the vapor deposition layer is an inorganic oxide layer using silicon oxide, the O / Si ratio of the inorganic oxide layer can be 1.5 or more from the viewpoint of transparency. In addition, the O / Si ratio can be 2.0 or less from the viewpoint of barrier property. From the viewpoint of more sufficiently obtaining the above-described effects, the O / Si ratio of the inorganic oxide layer can be 1.5 or more and 2.0 or less, or 1.6 or more and 1.8 or less.

[0170] The O / Si ratio of the above-described inorganic oxide layer can be found by X-ray photoelectron spectroscopy (XPS), for example, by measuring with a measuring device using an X-ray photoelectron spectrometer (manufactured by JEOL Ltd., trade name: JPS-90MXV), and an X-ray source using non-monochromatic MgKα (1253.6 eV) at an X-ray output power of 100 W (10 kV-10 mA). In the quantitative analysis for finding the O / Si ratio, the relative sensitivity factors of O1s of 2.28 and Si2p of 0.9 can be used, respectively.

[0171] The thickness of the vapor deposition layer can be 1 nm or more and 150 nm or less, 5 nm or more and 60 nm or less, or 5 nm or more and 40 nm or less. When the thickness of the vapor deposition layer is 1 nm or more, it is easy to obtain oxygen barrier property and water vapor barrier property. When the thickness of the vapor deposition layer is 150 nm or less, it is easy to prevent the generation of cracks in the vapor deposition layer, and it is easy to maintain the recycling property of the sealant film.

[0172] In the case where the gas barrier layer includes a metal foil, the thickness of the metal foil can be 1 μm or more and 15 μm or less, 3 μm or more and 10 μm or less, or 5 μm or more and 8 μm or less from the viewpoints of gas barrier properties and durability.

[0173] In the case where the gas barrier layer includes a resin film, the thickness of the resin film can be 100 nm or more and 50 μm or less, 500 nm or more and 10 μm or less, or 1 μm or more and 5 μm or less from the viewpoint of gas barrier properties.

[0174] The gas barrier layer can also be provided by laminating a vapor deposition film composed of a metal or inorganic oxide or the like on an inorganic material layer formed by a method other than vapor deposition, a laminated film of a metal foil and a plastic film, or a plastic film. As the plastic film, polyethylene terephthalate (PET), a polyester such as polyethylene naphthalate, a polyolefin such as polyethylene or polypropylene, polystyrene, a polyamide such as 6-nylon, polycarbonate, polyacrylonitrile, polyimide, or the like can be mentioned.

[0175] In the case where the gas barrier layer is a resin layer having gas barrier properties such as EVOH or polyvinyl alcohol resin, the resin layer can also be provided by co-extrusion or wet coating. In the case where the gas barrier layer is a resin film, a laminated film, or a vapor deposition film as described above, these gas barrier layers can be formed by lamination using an adhesive described later, extrusion lamination, or the like.

[0176] The auxiliary layer 4 provided with the gas barrier layer can have the same constitution as the sealant layer 3 described above. In the case where the auxiliary layer 4 includes a polyolefin resin, the polyolefin resin is preferably highly crystalline from the viewpoints of printability, vapor deposition suitability, strength, and heat resistance. The polyolefin resin can be a pure resin.

[0177] In the case where the polyolefin resin described above is polyethylene, high-density polyethylene (HDPE) and medium-density polyethylene (MDPE) are preferable from the viewpoints of vapor deposition suitability, printability, strength, and heat resistance, and medium-density polyethylene is more preferable from the viewpoint of stretchability. In the case where the polyolefin resin described above is polypropylene, the crystallinity based on the heat of fusion using a differential scanning calorimeter (DSC) can be 40% or more, and can also be 45% or more from the viewpoints of printability, strength, and heat resistance, and can be 60% or less, and can also be 55% or less from the viewpoint of impact resistance.

[0178] The proportion of non-material recycled resin (pure resin, chemically recycled resin, etc.) in the auxiliary layer 4, which has a gas barrier layer, can be higher than the proportion of non-material recycled resin in the recycled material layer. In this case, the local expansion originating from the aggregate on the surface of the recycled material layer can be smoothed, and the mechanical properties and gas barrier properties of the laminate can be improved.

[0179] From the viewpoint of gas barrier properties and airtightness, the thickness of the auxiliary layer 4, to which the gas barrier layer is provided, can be 20 μm or more, 40 μm or more, or 80 μm or more. From the viewpoint of suppressing the total thickness when used as a packaging material, it can be 150 μm or less, 120 μm or less, or 100 μm or less.

[0180] Alternatively, the laminate may sequentially include, for example, the sealant film, the adhesive layer, and the substrate film of this embodiment.

[0181] In the production of packaging materials with design and gas barrier functions, a substrate film with functional layers such as printed or vapor-deposited layers is sometimes bonded to a sealant film using an adhesive. However, if the sealant film has low smoothness, air bubbles can easily form in the resulting laminate, leading to poor appearance. The laminate described above, containing recycled materials with two or more resins, offers sufficient reliability and film-forming properties during heat sealing, as well as excellent appearance.

[0182] Figure 6 This is a schematic cross-sectional view representing an example of the aforementioned stacked structure. Figure 6 The laminate 10c shown includes a sealant film 1a having a recyclable material layer 2 and a sealant layer 3 laminated thereon, and a substrate film 6 having a recyclable material layer 2 laminated on the sealant film 1a by an adhesive layer 5.

[0183] Figure 7 This is a schematic cross-sectional view showing another example of the aforementioned stacked structure. Figure 7 The stacked body 10d shown has Figure 3 The sealant film 1b shown and the substrate film 6, which is laminated on the auxiliary layer 4 of the sealant film 1b through an adhesive layer 5.

[0184] In the aforementioned laminate, the auxiliary layer 4 can be further provided with a gas barrier layer on the side opposite to the side containing the recycled material layer 2. In this case, the laminate can become a laminate with improved gas barrier properties (e.g., oxygen barrier and water vapor barrier properties). The gas barrier layer can be a single-layer structure or a laminated structure.

[0185] The adhesive layer 5 functions as a layer that bonds the base film 6 to the sealant film. For example, in the laminate 10c, the recycled material-containing layer 2 of the sealant film is bonded to the base film 6 via the adhesive layer 5, and in the laminate 10d, the auxiliary layer 4 of the sealant film is bonded to the base film 6 via the adhesive layer 5.

[0186] Figure 6 and Figure 7 The laminate shown in the above formula (1) can be made into a packaging material.

[0187] As the base film 6, there is no particular limitation as long as it has mechanical strength and dimensional stability, and a plastic film, paper, nonwoven fabric, or the like can be used. As a constituent material of the plastic film, polyethylene terephthalate (PET), a polyester such as polyethylene naphthalate, a polyolefin such as polyethylene or polypropylene, polystyrene, a polyamide such as 6-nylon, polycarbonate, polyacrylonitrile, polyimide, or the like can be given.

[0188] From the viewpoint of mechanical strength and dimensional stability, the base film 6 is preferably a stretched film.

[0189] The base film 6 can be monomaterialized as a whole packaging material by containing the same kind of resin as the resin having the largest content ratio in the sealant film (also referred to as "the same resin"), and the recycling property of the packaging material is improved. In this case, all layers constituting the sealant film (for example, the sealant layer, or the sealant layer and the auxiliary layer) can contain the same kind of resin as the resin having the largest content ratio in the recycled material-containing layer.

[0190] The content of the same resin in the laminate (or the packaging material described later) can be 90% by mass or more, based on the total amount of the laminate (or the packaging material). The laminate (or the packaging material) in this case can be referred to as a packaging material composed of a single raw material (monomaterial). From the viewpoint of further improving the recycling property, the content of the same resin in the laminate (or the packaging material) can be 92.5% by mass or more, and can be 95% by mass or more, based on the total amount of the laminate (or the packaging material).

[0191] From the viewpoint of transparency, the haze value of the base film 6 can be 30% or less, and can be 20% or less. In addition, in the present specification, the haze value of a film refers to a value measured in accordance with JIS K 7105.

[0192] The base film 6 can be subjected to surface treatment. In this case, the adhesion to an adjacent layer can be improved. The method of surface treatment is not particularly limited, and physical treatment such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen and / or nitrogen, glow discharge treatment, and chemical treatment such as oxidation treatment using a chemical agent can be given.

[0193] An anchor coating layer can be provided on the surface of the base film 6 using a conventional anchor coating agent.

[0194] The thickness of the base film 6 can be 10 μm or more and 50 μm or less, or 12 μm or more and 30 μm or less. When the thickness of the base film is 10 μm or more, the strength of the laminate (or the packaging material) is easily improved. In addition, when the thickness of the base film is 50 μm or less, the processability of the laminate (or the packaging material) is easily maintained.

[0195] As the adhesive constituting the adhesive layer 5, there is no particular limitation, and a dry lamination adhesive, a solventless adhesive (also referred to as "solventless adhesive") can be used. As the dry lamination adhesive, a two-component curable urethane-based adhesive, a polyester urethane-based adhesive, a polyether urethane-based adhesive, an acrylic-based adhesive, a polyester-based adhesive, a polyamide-based adhesive, an epoxy-based adhesive, and the like can be given.

[0196] In the case where the packaging material is used for a retort packaging bag, a two-component curable urethane-based adhesive having retort resistance can be used.

[0197] As the solventless adhesive, for example, a two-component curable polyurethane-based adhesive in which a 2 or more functional aromatic or aliphatic isocyanate compound as a curing agent acts on a main agent such as a polyester polyol, a polyether polyol, an acrylic polyol, and the like can be given. Such an adhesive is cured by a reaction (for example, a reaction of a hydroxyl group of the main agent and an isocyanate group of the curing agent) by heating or the like, and thereby an adhesive layer is formed. The adhesive layer in this case can also be referred to as an adhesive layer formed of a reaction cured product of a solventless adhesive (also referred to as "solventless adhesive layer").

[0198] From the viewpoint of seeking improvement in adhesiveness, the solventless adhesive can set the equivalent ratio (NCO group / OH group molar ratio) of the isocyanate group of the curing agent and the hydroxyl group of the main agent to 0.5 to 5, for example. The adhesive layer formed not using a solvent-based adhesive but using a solventless adhesive can be analyzed by Fourier transform infrared spectroscopy, for example.

[0199] As the adhesive constituting the adhesive layer, from the viewpoint of making the appearance of the laminate more favorable, a solventless adhesive can be used. In the case where the base material film is attached to the sealant film using a dry lamination adhesive, the adhesive dissolved in a solvent is usually applied to the base material film, and after the solvent is removed using a drying oven, the sealant film is attached. The dry lamination adhesive after the removal of the solvent is hard, and has low freedom of shape deformation, but the solventless adhesive has high freedom of shape deformation at the time of adhesion, and thus even if the sealant film has a concave-convex shape, the solventless adhesive more easily follows the surface shape. Therefore, the solventless adhesive layer formed using the solventless adhesive is less likely to generate air bubbles between the base material film and the sealant film due to voids, and also enables improvement of adhesion.

[0200] In addition, the solventless adhesive has the characteristics of low environmental load in the manufacturing process, and can be applied thinner than the solvent-based adhesive. Therefore, the adhesive layer formed from the solventless adhesive has a tendency to be thin in thickness. In the laminate of the present embodiment, in the case where the adhesive layer formed from the solventless adhesive is combined with the sealant film of the present embodiment in which the surface concave-convex is sufficiently small, high adhesive strength can be obtained with an even lower adhesive application amount, and a favorable appearance in which the generation of air bubbles is suppressed can be obtained.

[0201] From the viewpoint of environmental protection, the adhesive layer 5 can satisfy at least one of the following conditions.

[0202] (1) does not contain 3-glycidyloxypropyltrimethoxysilane (GPTMS).

[0203] (2) contains a biomass material.

[0204] (3) does not contain a solvent.

[0205] From the viewpoint of suppressing coloring of recycled resins and the like and the generation of an odor caused by heat treatment after recycling, the adhesive layer 5 can not contain chlorine.

[0206] The thickness of the adhesive layer can be 0.3 μm or more and 5.0 μm or less. From the viewpoint of exhibiting adhesive strength, the thickness of the adhesive layer can be 0.3 μm or more, 0.5 μm or more, or 1 μm or more, and from the viewpoint of recyclability, the thickness of the adhesive layer can be 5.0 μm or less, 3.5 μm or less, or 2.5 μm or less. If the thickness of the adhesive layer is the above upper limit value or less, the ratio of a single material in the packaging material can be increased.

[0207] <packaging material> The packaging material of the present embodiment is provided with the above-described sealant film of the present embodiment. Figure 8 is a schematic cross-sectional view showing one embodiment of a packaging material. Figure 8The packaging material 100 shown includes a sealant film 1b having an auxiliary layer 4 and a substrate film 6 laminated on the auxiliary layer 4 via an adhesive layer 5.

[0208] The adhesive layer 5 is the layer that bonds the substrate film 6 to the sealant film. In the packaging material 10, the auxiliary layer 4 of the sealant film and the substrate film 6 are bonded together by the adhesive layer 5.

[0209] The packaging material of this embodiment may further include functional layers such as a printing layer and a gas barrier layer. These functional layers can be disposed on the aforementioned substrate film.

[0210] The printed layer can be formed on the side of the substrate film where the sealant film is located. In this case, the printed layer can be prevented from contacting external gases, thus preventing degradation over time.

[0211] The printed layer can display text, patterns, symbols, and combinations thereof.

[0212] From the perspective of creating packaging materials with a less environmentally impactful approach, the printing layer can be formed using inks derived from biomass.

[0213] There are no particular limitations on the method for forming the printed layer; conventional printing methods such as gravure printing, offset printing, and flexographic printing can be used. Among these, flexographic printing is preferable from an environmental perspective.

[0214] The gas barrier layer can be disposed on the substrate film and can have the same structure as the gas barrier layer 12 described above.

[0215] Alternatively, a gas barrier layer can be provided by laminating a metal foil and a plastic film, or by depositing a vapor-deposited layer (vapor-deposited film) composed of the aforementioned metal or inorganic oxides onto a plastic film. Examples of plastic films include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate, polyolefins such as polyethylene and polypropylene, polystyrene, polyamides such as 6-nylon, polycarbonate, polyacrylonitrile, and polyimide.

[0216] Figure 9 and Figure 10 This is a schematic cross-sectional view illustrating another embodiment of the packaging material.

[0217] Figure 9 The packaging material 101 shown includes a sealant film 1b having an auxiliary layer 4 and a substrate film 6 having a gas barrier layer 12 laminated on the auxiliary layer 4 by an adhesive layer 5.

[0218] Figure 10The packaging material 102 shown has: a laminate 10b in which a sealant film 1b having a sealant layer 3, a layer 2 containing a recycled material, and a sublayer 4 are sequentially stacked, and a gas barrier layer 12; and a base film 6 having a print layer 7 bonded to the gas barrier layer 12 side of the laminate via an adhesive layer 5. In the packaging material 102, as described above, the print layer 7 is formed on the side of the base film 6 on which the sealant film is provided.

[0219] The above-described additives can be contained in each layer of the packaging material of the present embodiment.

[0220] The packaging material of the present embodiment can be modified in various ways other than the above-described configuration, and can have the following configurations.

[0221] (a) Sealant film / adhesive layer / gas barrier film / adhesive layer / base film of the present embodiment (b) Sealant film / adhesive layer / gas barrier film of the present embodiment (c) Sealant film / gas barrier layer (e.g., vapor-deposited layer) / adhesive layer / base film of the present embodiment As the above-described gas barrier film, the above-described base film provided with a gas barrier layer, the laminated film of a metal foil and a plastic film, and the vapor-deposited film can be used, and a metal foil such as an aluminum foil, and a film of an ethylene / vinyl alcohol copolymer, a polyamide-based resin, a polyvinylidene chloride-based resin, a polyacrylonitrile-based resin, and the like can be used.

[0222] The packaging material can further have: a sealant film having a sublayer; a first base film laminated on the sublayer via an adhesive layer; and a second base film having a print layer laminated on the first base film via an adhesive layer. In addition, the packaging material can further have a sealant film having a sublayer, and a first base film laminated on the sublayer via an adhesive layer, and can further have a sealant film having a sublayer, a first base film laminated on the sublayer via an adhesive layer, and a gas barrier layer provided on the first base film, and can further have a sealant film having a sublayer, a first base film laminated on the sublayer via an adhesive layer, and two or more functional layers such as a gas barrier layer and a print layer provided on the first base film.

[0223] From the viewpoint of material recycling, the content of the plastic material contained in the recycled material of the packaging material (or the laminate) of the present embodiment can be 10% by mass or more, and can be 25% by mass or more, based on the total amount of the plastic material in the packaging material (or the laminate). In the case where the packaging material of the present embodiment is a laminated packaging material, materials other than plastic (e.g., an adhesive, printing ink, an aluminum foil, and the like) can be excluded from the weight calculation.

[0224] Examples of plastic materials (so-called recycled plastics) included in recycled materials include the resin contained in the recycled material layer of this embodiment described above. The pre-consumer material in the recycled plastic can be calculated by multiplying its weight by 1 / 2.

[0225] The packaging material (or the laminate of this embodiment) can be used for stand-up pouches, three-side seal pouches, gusseted pouches, accordion pouches, pouches with spouts, pouches with openings, etc.

[0226] <Packaging Bags> The packaging bag of this embodiment is made from the packaging material described above. There are no particular limitations on the style of the packaging bag; it can be a stand-up pouch, a three-side seal pouch, a gusseted pouch, a pouch with a spout, a pouch with an opening, etc.

[0227] Example The following examples illustrate the present invention in detail, but the present invention is not limited to these examples.

[0228] <Preparation of Materials for Material Recycling> (Recycled material 1) A film consisting of an LLDPE film (manufactured by Mitsui Chemicals Tohcello Co., Ltd., product name "TUX FC-S", film thickness 100μm), an adhesive layer, a PET film (manufactured by Toray Film Processing Co., Ltd., product name "VM-PET 1310", film thickness 12μm, aluminum vapor deposition), an adhesive layer, and a Ny film (manufactured by Toyobo, product name "HARDEN FILM N1100", film thickness 15μm) is compressed, cut, and shaped into granules to obtain recyclable material 1. Furthermore, the adhesive layer is formed by dry lamination using an adhesive mixture containing DIC-DRYLX-500 (manufactured by DIC GRAPHICS) as the main agent, KW75 (manufactured by DIC GRAPHICS) as the curing agent, and NC401 (manufactured by Toyo Ink) as the solvent.

[0229] (Recycled material 2) A membrane consisting of sequentially stacked LLDPE membrane (Mitsui Chemicals Tohcello, product name "TUX FC-S", 100 μm thick), adhesive layer, HDPE membrane (Tamapoly, product name "HF31", 35 μm thick), adhesive layer, and HDPE membrane (Tamapoly, product name "HF31", 35 μm thick) is compressed, cut, and shaped into granules to obtain recycled material 2. The adhesive layer is formed in the same manner as recycled material 1.

[0230] Preparation of a chemically recycled resin (CR-PE) Ethylene was polymerized using naphtha generated by anaerobic thermal cracking of waste plastics to obtain a chemically recycled polyethylene (density: 0.94 g / cm3, MFR: 1.0 g / 10 minutes).

[0231] (CR-PP) Propylene was polymerized using naphtha generated by anaerobic thermal cracking of waste plastics to obtain a chemically recycled polypropylene (crystallinity: 48%, MFR: 1.2 g / 10 minutes).

[0232] Preparation of a biomass-derived polyethylene-based resin (biomass LLDPE) A biomass-derived LLDPE "SLL118" (manufactured by Braskem, trade name, density: 0.916 g / cm3, MFR: 1.3 g / 10 minutes, biomass degree: 87%) was prepared.

[0233] Preparation of inorganic particles (inorganic particles 1) As the inorganic particles, titanium oxide (manufactured by DIC Corporation, titanium oxide PEONY HP WHITE series, model number: L-11232-MPT) was prepared.

[0234] Production of a sealant film A (Example A1) A chemically recycled material 1 was fed into a hopper for extruding a recycled material layer, and LLDPE (manufactured by Prime Polymer, product name "Evolue SP1540") to which 6000 ppm of an anti-blocking agent (manufactured by Prime Polymer, product name "EAZ-20") was added by dry blending was fed into a hopper for extruding a sealant layer, and a sealant film was produced by co-extrusion molding using a single-screw multilayer extruder to form a recycled material layer having a thickness of 30 μm and a sealant layer having a thickness of 70 μm. In addition, the screw rotation speed at the time of extruding the recycled material layer was 16 rpm, the narrowing of the flow path before the T die was avoided as much as possible, a mechanism that made it difficult to apply a tensile stress was formed, and the molten resin was cooled by a cooling roll provided with a matte style concave-convex shape (surface roughness Rz: 6 μm) using an air knife and sandblasting processing.

[0235] (Example A2) A recycled material layer having a thickness of 80 μm and a sealant layer having a thickness of 20 μm were produced by adjusting the extrusion amount of each layer (the screw rotation speed at the time of extruding the recycled material layer was changed to 43 rpm), and a sealant film was produced in the same manner as in Example A1, except for this.

[0236] (Example A3) The thickness of the recycled material-containing layer was adjusted to 90 μm and the thickness of the sealant layer was adjusted to 10 μm, and a sealant film was produced in the same manner as in Example Al, except that the extrusion amount of each layer was adjusted (the screw rotation speed when the recycled material-containing layer was extruded was changed to 48 rpm) and the molten resin was cooled at a pressure of 1.4 MPa using a cooling roll provided with a matte-style concave-convex shape (surface roughness Rz: 6 μm) by sandblasting processing and a nip roll (material: fluorine resin).

[0237] (Example A4) The thickness of the recycled material-containing layer was adjusted to 90 μm and the thickness of the sealant layer was adjusted to 10 μm, and a sealant film was produced in the same manner as in Example Al, except that the extrusion amount of each layer was adjusted (the screw rotation speed when the recycled material-containing layer was extruded was changed to 48 rpm) and the molten resin was cooled at a pressure of 1.4 MPa using a cooling roll provided with a matte-style concave-convex shape (surface roughness Rz: 6 μm) by sandblasting processing and a nip roll (material: fluorine resin).

[0238] (Example A5) The thickness of the recycled material-containing layer was adjusted to 80 μm and the thickness of the sealant layer was adjusted to 20 μm, and a sealant film was produced in the same manner as in Example Al, except that the extrusion amount of each layer was adjusted (the screw rotation speed when the recycled material-containing layer was extruded was changed to 43 rpm) and recycled material 2 was fed into the hopper for extruding the recycled material-containing layer.

[0239] (Example A6) The thickness of the recycled material-containing layer was adjusted to 90 μm and the thickness of the sealant layer was adjusted to 10 μm, and a sealant film was produced in the same manner as in Example A5, except that the extrusion amount of each layer was adjusted (the screw rotation speed when the recycled material-containing layer was extruded was changed to 48 rpm).

[0240] (Example A7) The thickness of the recycled material-containing layer was adjusted to 95 μm and the thickness of the sealant layer was adjusted to 5 μm, and a sealant film was produced in the same manner as in Example A5, except that the extrusion amount of each layer was adjusted (the screw rotation speed when the recycled material-containing layer was extruded was changed to 51 rpm).

[0241] (Example A8) The thickness of the recycled material-containing layer was adjusted to 90 μm and the thickness of the sealant layer was adjusted to 10 μm, and a sealant film was produced in the same manner as in Example A5, except that the extrusion amount of each layer was adjusted (the screw rotation speed when the recycled material-containing layer was extruded was changed to 48 rpm) and the molten resin was cooled at a pressure of 1.4 MPa using a cooling roll provided with a matte-style concave-convex shape (surface roughness Rz: 6 μm) by sandblasting processing and a nip roll (material: fluorine resin).

[0242] (Example A9) In the hopper for extruding the layer containing recycled material, recycled material 1 and LLDPE (manufactured by Prime Polymer Co., Ltd., product name "Evolue SP2040") were put in at a weight ratio of 1 : 1, and otherwise, the same as in Example A2, a sealant film was produced.

[0243] (Example A10) To the hopper for extruding the sealant layer, a block polypropylene resin (bPP) (manufactured by Japan Polypropylene Co., Ltd., product name "NOVATEC PP BC6DRF") to which 6000 ppm of an anti-blocking agent (manufactured by Prime Polymer Co., Ltd., product name "EAZ-20") was added by dry blending was put in, and otherwise, the same as in Example A2, a sealant film was produced.

[0244] (Example A11) To the hopper for extruding the layer containing recycled material, only recycled material 1 was put in, to the hopper for extruding the sealant layer, LLDPE (manufactured by Prime Polymer Co., Ltd., product name "Evolue SP1540") to which 6000 ppm of an anti-blocking agent (manufactured by Prime Polymer Co., Ltd., product name "EAZ-20") was added by dry blending was put in, and to the hopper for extruding the auxiliary layer, LLDPE (manufactured by Prime Polymer Co., Ltd., product name "Evolue SP1540") was put in, and using a single-screw multilayer extruder, an auxiliary layer having a thickness of 20 μm, a layer containing recycled material having a thickness of 80 μm, and a sealant layer having a thickness of 20 μm were sequentially produced by co-extrusion molding, and a sealant film was produced. Further, the screw rotation speed at the time of extruding the layer containing recycled material was 43 rpm, the narrowing of the flow path before the T die was avoided as much as possible, a mechanism that made it difficult to apply a tensile stress was formed, the molten resin was cooled by a cooling roll provided with a matte style concave-convex shape (surface roughness Rz: 6 μm) using air knives and sandblasting processing, and a sealant film was produced.

[0245] (Comparative Example A1) A sealant film was produced in the same manner as in Example Al except that no anti-blocking agent was added in the sealant layer.

[0246] (Comparative Example A2) The extrusion amounts of the respective layers were adjusted (the screw rotation speed at the time of extruding the layer containing recycled material was changed to 51 rpm) to produce a layer containing recycled material having a thickness of 95 μm and a sealant layer having a thickness of 5 μm, and otherwise, a sealant film was produced in the same manner as in Example Al.

[0247] (Comparative Example A3) The recycled material 2 was charged into the hopper for extrusion of the recycled material layer, no anti-blocking agent was added to the sealant layer, and the sealant film was produced in the same manner as in Example Al except that the thickness of the recycled material layer was 80 μm and the thickness of the sealant layer was 20 μm and the extrusion amount of each layer was adjusted (the screw rotation speed during extrusion of the recycled material layer was changed to 43 rpm).

[0248] (Comparative Example A4) The recycled material 2 was charged into the hopper for extrusion of the recycled material layer, and the sealant film was produced in the same manner as in Example Al except that the thickness of the recycled material layer was 98 μm and the thickness of the sealant layer was 2 μm and the extrusion amount of each layer was adjusted (the screw rotation speed during extrusion of the recycled material layer was changed to 52 rpm).

[0249] (Comparative Example A5) The sealant film was produced in the same manner as in Example Al except that the amount of the anti-blocking agent added was changed to 600 ppm.

[0250] <Surface roughness of sealant layer> The arithmetic surface roughness Ra of the surface of the sealant layer on the side opposite to the recycled material layer side was measured in accordance with the JIS B 0601:2001 standard.

[0251] <Reliability evaluation at the time of sealing> A heat sealer (Model TP-701-B) manufactured by TESTER Industry was used to seal the heat seal layers of the sealant film to each other with the sealing pressure set to 0.2 MPa, the sealing time set to 1 second, and the sealing width set to 10 mm. The heat seal temperature was a temperature of about 20°C higher than the melting point of the material of the heat seal layer (130°C in the case of LLDPE and 180°C in the case of PP). Then, the heat seal portion was observed with a microscope, and the area ratio of the bubbles present in the 1 mm2observation area was calculated. The case where the area ratio of the bubbles was 0% or more and less than 5% was rated "O", the case where the area ratio was 5% or more and less than 10% was rated "Δ", the case where the area ratio was 10% or more and less than 20% was rated "X", and the case where the area ratio was 20% or more was rated "T". 2

[0252] <Protrusions of laminated layer> The maximum height H of the protrusions on the surface of the laminated layer on the side opposite to the recycled material layer side (the difference between the height of the highest peak and the lowest valley in the prescribed range) and the width W at half the maximum height H of the protrusions were measured using a laser microscope (VK-X200 / VK-X210) manufactured by Keyence Corporation, and the ratio [W / H] of the width W to the maximum height H was calculated.

[0253] <Production property evaluation>​ From the start of film production to the winding, the observation of the appearance was performed by visual observation, and the film production property was evaluated in accordance with the following evaluation criteria.

[0254] "O": No generation of the bending and the wrinkle was observed from the start of the film production to the winding, and no appearance defect accompanying the generation of the bending and the wrinkle was observed in the film after the winding.

[0255] "X": The bending and the wrinkle were generated from the start of the film production to the winding, and the appearance defect accompanying the generation of the bending and the wrinkle was observed in the film after the winding.

[0256] As shown in Tables 1 and 2, it was confirmed that the sealant films of Examples Al to Al l sufficiently had the reliability at the heat sealing and the film production property while containing the recycled material. Therefore, according to the present application, the material recycling of the recycled material containing two or more kinds of resins can be achieved in the sealant film and the packaging material.

[0257] <Manufacture of the sealant film B> (Example Bl) A recycled material 1 was put into a hopper for extruding the recycled material layer, and a CR-PE to which 6000 ppm of an anti-blocking agent (manufactured by Prime Polymer, product name "EAZ-20") was added by dry blending was put into a hopper for extruding the sealant layer, and a recycled material layer having a thickness of 30 μm and a sealant layer having a thickness of 70 μm were manufactured by co-extrusion molding using a single-screw multilayer extruder, and a sealant film was manufactured. In addition, the screw rotation speed at the time of extruding the recycled material layer was 16 rpm, the narrowing of the flow path before the T die was avoided as much as possible, a mechanism in which the tensile stress was difficult to apply was formed, and the molten resin was cooled by a cooling roll provided with a matte style of concave-convex shape (surface roughness Rz: 6 μm) using an air knife and sandblasting processing.

[0258] (Example B2) The extrusion amounts of the layers were adjusted (the screw rotation speed at the time of extruding the recycled material layer was changed to 43 rpm) to manufacture a recycled material layer having a thickness of 80 μm and a sealant layer having a thickness of 20 μm, and a sealant film was manufactured in the same manner as Example Bl except for this.

[0259] (Example B3) The extrusion amounts of the layers were adjusted (the screw rotation speed at the time of extruding the recycled material layer was changed to 48 rpm) to manufacture a recycled material layer having a thickness of 90 μm and a sealant layer having a thickness of 10 μm, and a sealant film was manufactured in the same manner as Example Bl except for this.

[0260] (Example B4) A cooling roll provided with a matte style of concave-convex shape (surface roughness Rz: 6 μm) by sandblasting processing was used, and the molten resin was cooled under a pressure of 1.4 MPa, and the thickness of the recycled material-containing layer was adjusted to 90 μm and the thickness of the sealant layer was adjusted to 10 μm, and a sealant film was produced in the same manner as in Example B1, except that.

[0261] (Example B5) A recycled material 2 was put into the hopper for extruding the recycled material-containing layer, and the thickness of the recycled material-containing layer was adjusted to 80 μm and the thickness of the sealant layer was adjusted to 20 μm by adjusting the extrusion amount of each layer (the screw rotation speed at the time of extruding the recycled material-containing layer was changed to 43 rpm), and a sealant film was produced in the same manner as in Example B1, except that.

[0262] (Example B6) The thickness of the recycled material-containing layer was adjusted to 90 μm and the thickness of the sealant layer was adjusted to 10 μm by adjusting the extrusion amount of each layer (the screw rotation speed at the time of extruding the recycled material-containing layer was changed to 48 rpm), and a sealant film was produced in the same manner as in Example B5, except that.

[0263] (Example B7) The thickness of the recycled material-containing layer was adjusted to 95 μm and the thickness of the sealant layer was adjusted to 5 μm by adjusting the extrusion amount of each layer (the screw rotation speed at the time of extruding the recycled material-containing layer was changed to 51 rpm), and a sealant film was produced in the same manner as in Example B5, except that.

[0264] (Example B8) A cooling roll provided with a matte style of concave-convex shape (surface roughness Rz: 6 μm) by sandblasting processing was used, and the molten resin was cooled under a pressure of 1.4 MPa, and the thickness of the recycled material-containing layer was adjusted to 90 μm and the thickness of the sealant layer was adjusted to 10 μm by adjusting the extrusion amount of each layer (the screw rotation speed at the time of extruding the recycled material-containing layer was changed to 48 rpm), and a sealant film was produced in the same manner as in Example B5, except that.

[0265] (Example B9) A recycled material 1 and a CR-PE were put into the hopper for extruding the recycled material-containing layer in a weight ratio of 1:1, and a sealant film was produced in the same manner as in Example B2, except that.

[0266] (Example B10) To the hopper for extruding the sealant layer, CR-PP to which 6000 ppm of an anti-blocking agent (product name "EAZ-20" manufactured by Prime Polymer) was added by dry blending was charged, and a sealant film was produced in the same manner as in Example B2, except that the sealant film was produced.

[0267] (Example B11) To the hopper for extruding the layer containing recycled materials, only recycled material 1 was charged, to the hopper for extruding the sealant layer, CR-PE to which 6000 ppm of an anti-blocking agent (product name "EAZ-20" manufactured by Prime Polymer) was added by dry blending was charged, and to the hopper for extruding the auxiliary layer, CR-PE was charged, and a sealant film was produced by co-extrusion in the order of an auxiliary layer having a thickness of 20 μm, a layer containing recycled materials having a thickness of 80 μm, and a sealant layer having a thickness of 20 μm, using a single-screw multilayer extruder. Further, the screw rotation speed at the time of extruding the layer containing recycled materials was 43 rpm, the narrowing of the flow path before the T die was avoided as much as possible, a mechanism that made it difficult to apply a tensile stress was formed, the molten resin was cooled by a cooling roll provided with a matte style concavo-convex shape (surface roughness Rz: 6 μm) using sandblasting processing and an air knife, and a sealant film was produced.

[0268] (Comparative Example B1) A sealant film was produced in the same manner as in Example B1, except that no anti-blocking agent was added to the sealant layer.

[0269] (Comparative Example B2) The extrusion amounts of the respective layers were adjusted (the screw rotation speed at the time of extruding the layer containing recycled materials was changed to 51 rpm) to produce a layer containing recycled materials having a thickness of 95 μm and a sealant layer having a thickness of 5 μm, and a sealant film was produced in the same manner as in Example B1, except therefor.

[0270] (Comparative Example B3) To the hopper for extruding the layer containing recycled materials, recycled material 2 was charged, no anti-blocking agent was added to the sealant layer, the extrusion amounts of the respective layers were adjusted (the screw rotation speed at the time of extruding the layer containing recycled materials was changed to 43 rpm) to produce a layer containing recycled materials having a thickness of 80 μm and a sealant layer having a thickness of 20 μm, and a sealant film was produced in the same manner as in Example B1, except therefor.

[0271] (Comparative Example B4) To the hopper for extruding the layer containing recycled materials, recycled material 2 was charged, the extrusion amounts of the respective layers were adjusted (the screw rotation speed at the time of extruding the layer containing recycled materials was changed to 52 rpm) to produce a layer containing recycled materials having a thickness of 98 μm and a sealant layer having a thickness of 2 μm, and a sealant film was produced in the same manner as in Example B1, except therefor.

[0272] (Comparative Example B5) A sealant film was produced in the same manner as in Example B1 except that the amount of the anti-blocking agent added was changed to 600 ppm.

[0273] <Evaluation of the sealant film> The measurement of the surface roughness of the sealant layer, the reliability evaluation at the time of sealing, the evaluation of the convex portion of the laminate layer, and the evaluation of the film production property were performed in the same manner as in the above method, and further, the environmental load was evaluated as follows.

[0274] (Environmental load) As for the environmental load of the sealant film, the evaluation was performed in accordance with the following determination criteria.

[0275] [Determination criteria] : The content of the plastic material contained in the recycled material (including also the chemically recycled resin) in the sealant film was 100% by mass based on the total amount of the plastic material in the sealant film, and the content ratio of the material recycling material was 50% by mass or more based on the total mass of the sealant film.

[0276] : The content of the plastic material contained in the recycled material (including also the chemically recycled resin) in the sealant film was 100% by mass based on the total amount of the plastic material in the sealant film, and the content ratio of the material recycling material was less than 50% by mass.

[0277] : The content of the plastic material contained in the recycled material (including also the chemically recycled resin) in the sealant film was 90% by mass or more and less than 100% by mass based on the total amount of the plastic material in the sealant film.

[0278] : The content of the plastic material contained in the recycled material (including also the chemically recycled resin) in the sealant film was less than 90% by mass based on the total amount of the plastic material in the sealant film.

[0279] As shown in Tables 3 and 4, it was confirmed that the sealant films of Examples B1 to B11 sufficiently had the reliability at the time of heat sealing and the film production property while containing the recycled material. Therefore, according to the present application, it is possible to achieve the material recycling of the recycled material containing two or more kinds of resins in the sealant film and the packaging material.

[0280] [Production of the sealant film C] (Example C1) A recycling material 1 was charged into a hopper for extruding a recycling material layer, and a biomass LLDPE to which 6000 ppm of an anti-blocking agent (manufactured by Prime Polymer, product name "EAZ-20") was added by dry blending was charged into a hopper for extruding a sealant layer, and a sealant film was produced by co-extrusion molding using a single-screw multilayer extruder to form a recycling material layer having a thickness of 30 μm and a sealant layer having a thickness of 70 μm. In addition, the screw rotation speed at the time of extruding the recycling material layer was 16 rpm, and the narrowing of the flow path before the T die was avoided as much as possible to form a mechanism in which a tensile stress could not be applied, and the molten resin was cooled by a cooling roll provided with a matte style concave-convex shape (surface roughness Rz: 6 μm) using air knives and sandblasting processing.

[0281] (Example C2) A recycling material layer having a thickness of 80 μm and a sealant layer having a thickness of 20 μm were produced by adjusting the extrusion amounts of the respective layers (the screw rotation speed at the time of extruding the recycling material layer was changed to 43 rpm), and a sealant film was produced in the same manner as in Example Cl except for this.

[0282] (Example C3) A recycling material layer having a thickness of 90 μm and a sealant layer having a thickness of 10 μm were produced by adjusting the extrusion amounts of the respective layers (the screw rotation speed at the time of extruding the recycling material layer was changed to 48 rpm), and a sealant film was produced in the same manner as in Example Cl except for this.

[0283] (Example C4) A recycling material layer having a thickness of 90 μm and a sealant layer having a thickness of 10 μm were produced by adjusting the extrusion amounts of the respective layers and cooling the molten resin at a pressure of 1.4 MPa using a pinch roll (material: fluororesin) and a cooling roll provided with a matte style concave-convex shape (surface roughness Rz: 6 μm) using sandblasting processing, and a sealant film was produced in the same manner as in Example Cl except for this.

[0284] (Example C5) A recycling material 2 was charged into a hopper for extruding a recycling material layer, and the extrusion amounts of the respective layers were adjusted (the screw rotation speed at the time of extruding the recycling material layer was changed to 43 rpm) to produce a recycling material layer having a thickness of 80 μm and a sealant layer having a thickness of 20 μm, and a sealant film was produced in the same manner as in Example Cl except for this.

[0285] (Example C6) A recycling material layer having a thickness of 90 μm and a sealant layer having a thickness of 10 μm were produced by adjusting the extrusion amounts of the respective layers (the screw rotation speed at the time of extruding the recycling material layer was changed to 48 rpm), and a sealant film was produced in the same manner as in Example C5 except for this.

[0286] (Example C7) The extrusion amount of each layer was adjusted (the screw rotation speed when the layer containing recycled materials was extruded was changed to 51 rpm) to produce a layer containing recycled materials having a thickness of 95 μm and a sealant layer having a thickness of 5 μm, and a sealant film was produced in the same manner as in Example C5, except for this.

[0287] (Example C8) A cooling roll provided with a matte-style concave-convex shape (surface roughness Rz: 6 μm) by sandblasting processing and a nip roll (material: fluororesin) were used to cool the molten resin at a pressure of 1.4 MPa, and the extrusion amount of each layer was adjusted (the screw rotation speed when the layer containing recycled materials was extruded was changed to 48 rpm) to produce a layer containing recycled materials having a thickness of 90 μm and a sealant layer having a thickness of 10 μm, and a sealant film was produced in the same manner as in Example C5, except for this.

[0288] (Example C9) Biomass LLDPE and recycled material 1 were put into the hopper for extruding the layer containing recycled materials at a weight ratio of 1:1, and a sealant film was produced in the same manner as in Example C2, except for this.

[0289] (Example C10) Only recycled material 1 was put into the hopper for extruding the layer containing recycled materials, biomass LLDPE to which 6000 ppm of an anti-blocking agent (manufactured by Prime Polymer, product name "EAZ-20") was added by dry blending was put into the hopper for extruding the sealant layer, and biomass LLDPE was put into the hopper for extruding the auxiliary layer, and a sealant film was produced by sequentially producing an auxiliary layer having a thickness of 20 μm, a layer containing recycled materials having a thickness of 80 μm, and a sealant layer having a thickness of 20 μm by co-extrusion using a single-screw multilayer extruder, in the same manner as in Example C5, except for this. Furthermore, the screw rotation speed when the layer containing recycled materials was extruded was 43 rpm, the narrowing of the flow path before the T die was avoided as much as possible, a mechanism that made it difficult to apply a tensile stress was formed, the molten resin was cooled by a gas knife and a cooling roll provided with a matte-style concave-convex shape (surface roughness Rz: 6 μm) by sandblasting processing, and a sealant film was produced.

[0290] (Comparative Example C1) A sealant film was produced in the same manner as in Example C1, except that an anti-blocking agent was not added to the sealant layer.

[0291] (Comparative Example C2) The extrusion amount of each layer was adjusted (the screw rotation speed when the layer containing recycled materials was extruded was changed to 51 rpm) to produce a layer containing recycled materials having a thickness of 95 μm and a sealant layer having a thickness of 5 μm, and a sealant film was produced in the same manner as in Example C1, except for this.

[0292] (Comparative Example C3) A recycled material 2 was charged to the hopper for extruding the recycled material layer, no anti-blocking agent was added to the sealant layer, and the amounts of extrusion of the respective layers were adjusted (the screw rotation speed at the time of extruding the recycled material layer was changed to 43 rpm) to produce a recycled material layer having a thickness of 80 μm and a sealant layer having a thickness of 20 μm, and a sealant film was produced in the same manner as in Example Cl, except for the above.

[0293] (Comparative Example C4) A recycled material 2 was charged to the hopper for extruding the recycled material layer, and the amounts of extrusion of the respective layers were adjusted (the screw rotation speed at the time of extruding the recycled material layer was changed to 52 rpm) to produce a recycled material layer having a thickness of 98 μm and a sealant layer having a thickness of 2 μm, and a sealant film was produced in the same manner as in Example Cl, except for the above.

[0294] (Comparative Example C5) A sealant film was produced in the same manner as in Example Cl, except that the amount of addition of the anti-blocking agent was changed to 600 ppm.

[0295] <Evaluation of the sealant film> The surface roughness of the sealant layer, the reliability evaluation at the time of sealing, the evaluation of the convex portions of the laminated layers, and the film production property evaluation were performed in the same manner as in the above-described method, and further, the biomass degree was evaluated as follows.

[0296] (Biomass degree) The biomass degree of the sealant film was the content of carbon derived from biomass determined based on the concentration of radioactive carbon (C14), and was evaluated in accordance with the following evaluation criteria.

[0297] [Evaluation criteria] : The content of the biomass raw material in the sealant film was 30% by mass or more, based on the total mass of the sealant film.

[0298] : The content of the biomass raw material in the sealant film was 15% by mass or more and less than 30% by mass, based on the total mass of the sealant film.

[0299] : The content of the biomass raw material in the sealant film was 5% by mass or more and less than 15% by mass, based on the total mass of the sealant film.

[0300] : The content of the biomass raw material in the sealant film was less than 5% by mass, based on the total mass of the sealant film.

[0301] As shown in Tables 5 and 6, the sealant films of Examples C1 to C10 were confirmed to possess sufficient reliability and film-forming properties during heat sealing while containing recycled materials. Furthermore, the sealant films of Examples C1 to C10 contain more than 5% by mass of biomass raw materials, which can improve the biomass content of plastic-containing products. Therefore, according to the present invention, it is possible to achieve material recycling of recycled materials containing two or more resins in sealant films and packaging materials.

[0302] <Preparation of the sealant film D> (Example D1) Recycled material 1 is added to the hopper for extruding the recycled material layer, and LLDPE (Evolue SP1540 manufactured by Prime Polymer, produced by dry blending with 6000 ppm of anti-blocking agent (manufactured by Prime Polymer, product name "EAZ-20") is added to the hopper for extruding the sealant layer. A 30 μm thick recycled material layer and a 70 μm thick sealant layer are produced by co-extrusion molding using a single-screw multilayer extruder, forming a sealant film. Furthermore, the screw speed during extrusion of the recycled material layer is 16 rpm, and the flow path before the T-die is minimized to create a structure that is difficult to apply tensile stress. The molten resin is cooled by an air knife and a cooling roller with a matte textured surface (surface roughness Rz: 6 μm) processed by sandblasting.

[0303] Using an electron beam irradiation device (EES-L-DP01, a low-energy electron beam irradiation device of the line irradiation type, manufactured by Hamamatsu Photonics Co., Ltd.), the side of the sealant film obtained above, opposite to the sealant layer side, was irradiated with electron beams under the following conditions.

[0304] (Irradiation conditions) Voltage: 120kV Radiation dose: 100 kGy Oxygen concentration in the device: below 100 ppm Linear velocity: 25m / min (Example D2) The extrusion rate of each layer was adjusted (the screw speed when extruding the layer containing recycled material was changed to 43 rpm) to manufacture a layer containing recycled material with a thickness of 80 μm and a sealant layer with a thickness of 20 μm. Otherwise, the sealant film was made in the same manner as in Example D1 and irradiated with electron beams.

[0305] (Example D3) The extrusion amount of each layer was adjusted (the screw rotation speed when the layer containing recycled material was extruded was changed to 48 rpm) to produce a layer containing recycled material having a thickness of 90 μm and a sealant layer having a thickness of 10 μm, and a sealant film was produced in the same manner as in Example D1 except for this, and electron rays were irradiated.

[0306] (Example D4) A cooling roll provided with a matte-style concave-convex shape (surface roughness Rz: 6 μm) by sandblasting processing was used, and the molten resin was cooled at a pressure of 1.4 MPa, and the extrusion amount of each layer was adjusted (the screw rotation speed when the layer containing recycled material was extruded was changed to 48 rpm) to produce a layer containing recycled material having a thickness of 90 μm and a sealant layer having a thickness of 10 μm, and a sealant film was produced in the same manner as in Example D1 except for this, and electron rays were irradiated.

[0307] (Example D5) The recycled material 2 was put into the hopper for extruding the layer containing recycled material, and the extrusion amount of each layer was adjusted (the screw rotation speed when the layer containing recycled material was extruded was changed to 43 rpm) to produce a layer containing recycled material having a thickness of 80 μm and a sealant layer having a thickness of 20 μm, and a sealant film was produced in the same manner as in Example D1 except for this, and electron rays were irradiated.

[0308] (Example D6) The extrusion amount of each layer was adjusted (the screw rotation speed when the layer containing recycled material was extruded was changed to 48 rpm) to produce a layer containing recycled material having a thickness of 90 μm and a sealant layer having a thickness of 10 μm, and a sealant film was produced in the same manner as in Example D5 except for this, and electron rays were irradiated under the same conditions as in Example D1.

[0309] (Example D7) The extrusion amount of each layer was adjusted (the screw rotation speed when the layer containing recycled material was extruded was changed to 51 rpm) to produce a layer containing recycled material having a thickness of 95 μm and a sealant layer having a thickness of 5 μm, and a sealant film was produced in the same manner as in Example D5 except for this, and electron rays were irradiated under the same conditions as in Example D1.

[0310] (Example D8) A cooling roll provided with a matte-style concave-convex shape (surface roughness Rz: 6 μm) by sandblasting processing was used, and the molten resin was cooled at a pressure of 1.4 MPa, and the extrusion amount of each layer was adjusted (the screw rotation speed when the layer containing recycled material was extruded was changed to 48 rpm) to produce a layer containing recycled material having a thickness of 90 μm and a sealant layer having a thickness of 10 μm, and a sealant film was produced in the same manner as in Example D5 except for this, and electron rays were irradiated under the same conditions as in Example D1.

[0311] (Example D9) In a hopper for extruding a layer containing recycled material, recycled material 1 and LLDPE (manufactured by Prime Polymer Co., Ltd., product name "Evolue SP2040") were put in a weight ratio of 1 : 1, and otherwise, a sealant film was produced in the same manner as in Example D2, and electron rays were irradiated under the same conditions as in Example Dl.

[0312] (Example D10) To a hopper for extruding a sealant layer, block PP (manufactured by Japan Polypropylene Co., Ltd., product name "NOVATEC PPBC6DRF") to which 6000 ppm of an anti-blocking agent (manufactured by Prime Polymer, product name "EAZ-20") was added by dry blending was put, and otherwise, a sealant film was produced in the same manner as in Example D2, and electron rays were irradiated under the same conditions as in Example Dl.

[0313] (Example D11) To a hopper for extruding a layer containing recycled material, only recycled material 1 was put, to a hopper for extruding a sealant layer, LLDPE (manufactured by Prime Polymer Co., Ltd., product name "Evolue SP1540") to which 6000 ppm of an anti-blocking agent (manufactured by Prime Polymer, product name "EAZ-20") was added by dry blending was put, and to a hopper for extruding an auxiliary layer, LLDPE (manufactured by Prime Polymer Co., Ltd., product name "Evolue SP1540") was put, and an auxiliary layer having a thickness of 20 μm, a layer containing recycled material having a thickness of 80 μm, and a sealant layer having a thickness of 20 μm were sequentially produced by co-extrusion using a single-screw multilayer extruder, and a sealant film was produced. Further, the screw rotation speed at the time of extruding the layer containing recycled material was 43 rpm, the narrowing of the flow path before the T die was avoided as much as possible, a mechanism in which a tensile stress was difficult to apply was formed, the molten resin was cooled by a cooling roll provided with a matte style concave-convex shape (surface roughness Rz: 6 μm) using air knives and sandblasting processing, and a sealant film was produced.

[0314] The sealant film thus obtained was irradiated with electron rays in the same manner as in Example Dl.

[0315] (Reference Example 1) A commercially available sealant film made of PE (manufactured by Tamapoly Co., Ltd., product name "MZ434") was prepared.

[0316] (Comparative Example Dl) A sealant film was produced in the same manner as in Example Dl except that an anti-blocking agent was not added in the sealant layer, and electron rays were irradiated.

[0317] (Comparative Example D2) The extrusion amount of each layer was adjusted (the screw rotation speed at the time of extruding the layer containing recycled material was changed to 51 rpm) to produce a layer containing recycled material having a thickness of 95 μm and a sealant layer having a thickness of 5 μm, and a sealant film was produced in the same manner as in Example Dl except for this, and electron rays were irradiated.

[0318] (Comparative Example D3) The recycled material 2 was fed to the hopper for extruding the layer containing recycled material, no antiblocking agent was added to the sealant layer, the extrusion amount of each layer was adjusted (the screw rotation speed at the time of extruding the layer containing recycled material was changed to 43 rpm) to produce a layer containing recycled material having a thickness of 80 μm and a sealant layer having a thickness of 20 μm, and a sealant film was produced in the same manner as in Example Dl except for this, and electron rays were irradiated.

[0319] (Comparative Example D4) The recycled material 2 was fed to the hopper for extruding the layer containing recycled material, the extrusion amount of each layer was adjusted (the screw rotation speed at the time of extruding the layer containing recycled material was changed to 52 rpm) to produce a layer containing recycled material having a thickness of 98 μm and a sealant layer having a thickness of 2 μm, and a sealant film was produced in the same manner as in Example Dl except for this, and electron rays were irradiated.

[0320] (Comparative Example D5) A sealant film was produced in the same manner as in Example Dl except that the amount of the antiblocking agent added was changed to 600 ppm, and electron rays were irradiated.

[0321] <Evaluation of the sealant film> The surface roughness of the sealant layer was measured, the reliability at the time of sealing was evaluated, the evaluation of the convex portion of the laminated layer, and the evaluation of the film forming property were performed in the same manner as in the above-described method, and further the puncture strength was evaluated as follows.

[0322] (Puncture strength) A test piece was cut out from the sealant film in a size of 50 mm x 50 mm. Using TENSILON AD-7703 (manufactured by A&D Company, product name) and a special needle of a semicircular shape having a diameter of 1.0 mm and a tip shape radius of 0.5 mm, the maximum force (N) until the needle penetrated was measured under the conditions of a test speed of 50 mm / min, a load sensor of 100 N, and a load range of 10 N (10%), and this was evaluated as the puncture strength. At this time, if the strength was shown to be 1 time or more and less than 1.5 times as compared with a commercially available sealant film (Reference Example 1), it was evaluated as "O", and in the case where it was not as good as the commercially available sealant film, it was evaluated as "X".

[0323] As shown in Tables 7 and 8, the sealant films of Examples D1 to D11 were confirmed to possess sufficient reliability, puncture strength, and film-forming properties during heat sealing while containing recyclable materials. Therefore, according to the present invention, it is possible to achieve material recycling of recyclable materials containing two or more resins in sealant films and packaging materials.

[0324] <Preparation of Sealant Film E> (Example E1) Recycled material 1 is added to the hopper containing the recycled material layer, and inorganic particles 1 are further added in such a way that the content of the recycled material layer reaches 10% by mass. LLDPE (Evolue SP1540) with 6000 ppm of anti-blocking agent (EAZ-20) added by dry blending is added to the hopper containing the sealant layer. A 30 μm thick recycled material layer and a 70 μm thick sealant layer are produced by co-extrusion molding using a single-screw multilayer extruder to create a sealant film. Furthermore, the screw speed during extrusion of the recycled material layer is 16 rpm, and the narrowing of the flow path before the T-die is avoided as much as possible to form a structure that is difficult to apply tensile stress. The molten resin is cooled by an air knife and a cooling roller with a matte textured surface (surface roughness Rz: 6 μm) processed by sandblasting.

[0325] (Example E2) The extrusion rate of each layer was adjusted (the screw speed when extruding the layer containing recycled material was changed to 43 rpm) to manufacture a layer containing recycled material with a thickness of 80 μm and a sealant layer with a thickness of 20 μm. Otherwise, the sealant film was made in the same manner as in Example E1.

[0326] (Example E3) Adjust the extrusion rate of each layer (change the screw speed to 48 rpm when extruding the layer containing recycled material) to manufacture a 90 μm thick layer containing recycled material and a 10 μm thick sealant layer. Otherwise, operate in the same manner as in Example E1 to manufacture the sealant film.

[0327] (Example E4) The molten resin was cooled under a pressure of 1.4 MPa using a clamping roller (material: fluoropolymer) and a cooling roller with a matte textured surface (surface roughness Rz: 6 μm) obtained by sandblasting. The extrusion amount of each layer was adjusted to produce a 90 μm thick layer containing recycled material and a 10 μm thick sealant layer. Otherwise, the sealant film was produced in the same manner as in Example E1.

[0328] (Example E5) To the hopper for extruding the layer containing recycled material, recycled material 2 was put in place of recycled material 1, and the extrusion amounts of the layers were adjusted (the screw rotation speed at the time of extruding the layer containing recycled material was changed to 43 rpm) to produce a layer containing recycled material having a thickness of 80 μm and a sealant layer having a thickness of 20 μm, and a sealant film was produced in the same manner as in Example El except for this.

[0329] (Example E6) The extrusion amounts of the layers were adjusted (the screw rotation speed at the time of extruding the layer containing recycled material was changed to 48 rpm) to produce a layer containing recycled material having a thickness of 90 μm and a sealant layer having a thickness of 10 μm, and a sealant film was produced in the same manner as in Example E5 except for this.

[0330] (Example E7) The extrusion amounts of the layers were adjusted (the screw rotation speed at the time of extruding the layer containing recycled material was changed to 51 rpm) to produce a layer containing recycled material having a thickness of 95 μm and a sealant layer having a thickness of 5 μm, and a sealant film was produced in the same manner as in Example E5 except for this.

[0331] (Example E8) A cooling roll provided with a matte style of concave-convex shape (surface roughness Rz: 6 μm) by sandblasting processing and a nip roll (material: fluorine resin) were used to cool the molten resin under a pressure of 1.4 MPa, and the extrusion amounts of the layers were adjusted (the screw rotation speed at the time of extruding the layer containing recycled material was changed to 48 rpm) to produce a layer containing recycled material having a thickness of 90 μm and a sealant layer having a thickness of 10 μm, and a sealant film was produced in the same manner as in Example E5 except for this.

[0332] (Example E9) To the hopper for extruding the layer containing recycled material, recycled material 1 and LLDPE (manufactured by Prime Polymer, product name "Evolue SP2040") were put in at a weight ratio of 1 : 1, and a sealant film was produced in the same manner as in Example E2 except for this.

[0333] (Example E10) To the hopper for extruding the sealant layer, a block PP (manufactured by Japan Polypropylene, product name "NOVATEC PPBC6DRF") to which 6000 ppm of an antiblocking agent (manufactured by Prime Polymer, product name "EAZ-20") was added by dry blending was put in, and a sealant film was produced in the same manner as in Example E2 except for this.

[0334] (Example E11) To the hopper for extruding the recycled material-containing layer, recycled material 1 was charged, and further inorganic particles 1 were charged so as to be contained in the recycled material-containing layer at 10% by mass. To the hopper for extruding the sealant layer, LLDPE (manufactured by Prime Polymer Co., product name "Evolue SP1540") to which 6000 ppm of an anti-blocking agent (manufactured by Prime Polymer Co., product name "EAZ-20") was added by dry blending was charged, and to the hopper for extruding the auxiliary layer, LLDPE (manufactured by Prime Polymer Co., product name "Evolue SP2040") was charged, and a sealant film was produced by sequentially forming an auxiliary layer having a thickness of 20 μm, a recycled material-containing layer having a thickness of 80 μm, and a sealant layer having a thickness of 20 μm by co-extrusion using a single-screw multilayer extruder. Further, the screw rotation speed at the time of extruding the recycled material-containing layer was 43 rpm, and the narrowing of the flow path before the T die was avoided as much as possible, a mechanism that made it difficult to apply a tensile stress was formed, the molten resin was cooled by a cooling roll provided with a matte-style concavo-convex shape (surface roughness Rz: 6 μm) using air knives and sandblasting processing, and a sealant film was produced.

[0335] (Evaluation Example E12) To the hopper for extruding the recycled material-containing layer, recycled material 1 was charged, and further inorganic particles 1 were charged so as to be contained in the recycled material-containing layer at 5% by mass, and to the hopper for extruding the auxiliary layer, LLDPE (manufactured by Prime Polymer Co., product name "Evolue SP2040") was charged, and further inorganic particles 1 were charged so as to be contained in the auxiliary layer at 20% by mass, and a sealant film was produced in the same manner as in Example E11 except for this.

[0336] (Evaluation Example E13) To the hopper for extruding the recycled material-containing layer, only recycled material 1 was charged, and to the hopper for extruding the auxiliary layer, LLDPE (manufactured by Prime Polymer Co., product name "Evolue SP2040") was charged, and further inorganic particles 1 were charged so as to be contained in the auxiliary layer at 40% by mass, and a sealant film was produced in the same manner as in Example E11 except for this.

[0337] (Evaluation Example E14) The amount of inorganic particles 1 charged was adjusted so as to be contained in the recycled material-containing layer at 5% by mass, and a sealant film was produced in the same manner as in Example E2 except for this.

[0338] (Evaluation Example E15) The amount of inorganic particles 1 charged was adjusted so as to be contained in the recycled material-containing layer at 7% by mass, and a sealant film was produced in the same manner as in Example E2 except for this.

[0339] (Example E16) The amount of inorganic particles 1 was adjusted so that the content in the recycled material-containing layer was 20 mass%, and otherwise, the sealant film was produced in the same manner as in Example E2.

[0340] (Example E17) The amount of inorganic particles 1 was adjusted so that the content in the recycled material-containing layer was 23 mass%, and otherwise, the sealant film was produced in the same manner as in Example E2.

[0341] (Comparative Example E1) The sealant film was produced in the same manner as in Example E1, except that no anti-blocking agent was added to the sealant layer.

[0342] (Comparative Example E2) The recycled material-containing layer having a thickness of 95 μm and the sealant layer having a thickness of 5 μm were produced by adjusting the extrusion amount of each layer (the screw rotation speed at the time of extruding the recycled material-containing layer was changed to 51 rpm), and otherwise, the sealant film was produced in the same manner as in Example E1.

[0343] (Comparative Example E3) The recycled material-containing layer having a thickness of 80 μm and the sealant layer having a thickness of 20 μm were produced by adding the recycled material 2 to the hopper for extruding the recycled material-containing layer, not adding the anti-blocking agent to the sealant layer, adjusting the extrusion amount of each layer (the screw rotation speed at the time of extruding the recycled material-containing layer was changed to 43 rpm), and otherwise, the sealant film was produced in the same manner as in Example E1.

[0344] (Comparative Example E4) The recycled material-containing layer having a thickness of 98 μm and the sealant layer having a thickness of 2 μm were produced by adding the recycled material 2 to the hopper for extruding the recycled material-containing layer, adjusting the extrusion amount of each layer (the screw rotation speed at the time of extruding the recycled material-containing layer was changed to 52 rpm), and otherwise, the sealant film was produced in the same manner as in Example E1.

[0345] (Comparative Example E5) The sealant film was produced in the same manner as in Example E1, except that the amount of the anti-blocking agent was changed to 600 ppm.

[0346] (Comparative Example E6) The recycled material-containing layer having a thickness of 95 μm and the sealant layer having a thickness of 5 μm were produced by adjusting the extrusion amount of each layer (the screw rotation speed at the time of extruding the recycled material-containing layer was changed to 51 rpm), and otherwise, the sealant film was produced in the same manner as in Example E1, except that no inorganic particles 1 were added to the hopper for extruding the recycled material-containing layer.

[0347] < Evaluation of the sealant film > The surface roughness of the sealant layer, the reliability evaluation at the time of sealing, the evaluation of the convex portion of the laminated layer, and the film forming property evaluation were performed in the same manner as the above-described method, and further, the appearance (concealability) was evaluated as follows.

[0348] (Appearance: Concealability) The concealability of the sealant film obtained in each example was evaluated using a portable transmittance meter (Model 341C) manufactured by X-RITE. The case where the measured transmittance was less than 0.20 was evaluated as "X", the case where the transmittance was 0.20 or more and less than 0.40 was evaluated as "Δ", the case where the transmittance was 0.40 or more and less than 0.50 was evaluated as "O", and the case where the transmittance was 0.50 or more was evaluated as "◎".

[0349] As shown in Tables 9 to 11, it was confirmed that the sealant films of Examples E1 to E17 sufficiently had the reliability at the time of heat sealing and the film forming property while containing the recycled material. In addition, it was confirmed that the sealant films of Examples E1 to E15 were imparted with sufficient concealability by the addition of the inorganic particles. Therefore, according to the present application, it is possible to realize the material recycling of the recycled material containing two or more kinds of resins in the sealant film and the packaging material.

[0350] <Manufacture of the sealant film and the laminate F> (Example F1) A recycled material 1 was fed to a hopper for extruding the recycled material-containing layer, and LLDPE (manufactured by Prime Polymer, product name "Evolue SP1540") to which 6000 ppm of an anti-blocking agent (manufactured by Prime Polymer, product name "EAZ-20") was added by dry blending was fed to a hopper for extruding the sealant layer, and a recycled material-containing layer having a thickness of 30 μm and a sealant layer having a thickness of 70 μm were manufactured by co-extrusion molding using a single-screw multilayer extruder, thereby manufacturing a sealant film. In addition, the screw rotation speed at the time of extruding the recycled material-containing layer was 16 rpm, the narrowing of the flow path before the T die was avoided as much as possible, a mechanism in which the tensile stress could not be applied was formed, and the molten resin was cooled by a cooling roll provided with a matte style concave-convex shape (surface roughness Rz: 6 μm) using an air knife and sandblasting processing.

[0351] Next, on the recycled material-containing layer of the obtained sealant film, a 40-nm-thick evaporation layer composed of aluminum (aluminum evaporation layer) was formed using a vacuum evaporation device based on an electron beam heating method, and a laminate was produced.

[0352] (Example F2) The extrusion amount of each layer was adjusted (the screw rotation speed at the time of extruding the recycled material-containing layer was changed to 43 rpm) to produce a recycled material-containing layer having a thickness of 80 μm and a sealant layer having a thickness of 20 μm, and a sealant film was produced in the same manner as in Example Fl except for this. Next, an aluminum evaporation layer was formed on the sealant film in the same manner as in Example Fl, and a laminate was produced.

[0353] (Example F3) The extrusion amount of each layer was adjusted (the screw rotation speed at the time of extruding the recycled material-containing layer was changed to 48 rpm) to produce a recycled material-containing layer having a thickness of 90 μm and a sealant layer having a thickness of 10 μm, and a sealant film was produced in the same manner as in Example Fl except for this. Next, an aluminum evaporation layer was formed on the sealant film in the same manner as in Example Fl, and a laminate was produced.

[0354] (Example F4) A cooling roll provided with a matte-style concave-convex shape (surface roughness Rz: 6 μm) by sandblasting processing was used as a pinch roll (material: fluorine resin), and the molten resin was cooled at a pressure of 1.4 MPa, and the extrusion amount of each layer was adjusted to produce a recycled material-containing layer having a thickness of 90 μm and a sealant layer having a thickness of 10 μm, and a sealant film was produced in the same manner as in Example Fl except for this. Next, an aluminum evaporation layer was formed on the sealant film in the same manner as in Example Fl, and a laminate was produced.

[0355] (Example F5) A recycled material 2 was put into the hopper for extruding the recycled material-containing layer, and the extrusion amount of each layer was adjusted (the screw rotation speed at the time of extruding the recycled material-containing layer was changed to 43 rpm) to produce a recycled material-containing layer having a thickness of 80 μm and a sealant layer having a thickness of 20 μm, and a sealant film was produced in the same manner as in Example Fl except for this. Next, an aluminum evaporation layer was formed on the sealant film in the same manner as in Example Fl, and a laminate was produced.

[0356] (Example F6) The extrusion amount of each layer was adjusted (the screw rotation speed at the time of extruding the recycled material-containing layer was changed to 48 rpm) to produce a recycled material-containing layer having a thickness of 90 μm and a sealant layer having a thickness of 10 μm, and a sealant film was produced in the same manner as in Example F5 except for this. Next, an aluminum evaporation layer was formed on the sealant film in the same manner as in Example Fl, and a laminate was produced.

[0357] (Example F7) The extrusion amount of each layer was adjusted (the screw rotation speed at the time of extruding the recycled material-containing layer was changed to 51 rpm) to produce a recycled material-containing layer having a thickness of 95 μm and a sealant layer having a thickness of 5 μm, and a sealant film was produced in the same manner as in Example F5, except for this. Next, an aluminum vapor deposition layer was formed on the sealant film in the same manner as in Example Fl, and a laminate was produced.

[0358] (Example F8) A cooling roll provided with a matte-style concave-convex shape (surface roughness Rz: 6 μm) by sandblasting processing was used, and the molten resin was cooled at a pressure of 1.4 MPa, and the extrusion amount of each layer was adjusted (the screw rotation speed at the time of extruding the recycled material-containing layer was changed to 48 rpm) to produce a recycled material-containing layer having a thickness of 90 μm and a sealant layer having a thickness of 10 μm, and a sealant film was produced in the same manner as in Example F5, except for this. Next, an aluminum vapor deposition layer was formed on the sealant film in the same manner as in Example Fl, and a laminate was produced.

[0359] (Example F9) In the hopper for extruding the recycled material-containing layer, recycled material 1 and LLDPE (manufactured by Prime Polymer, product name "Evolue SP2040") were put in such that the weight ratio became 1 : 1, and a sealant film was produced in the same manner as in Example F2, except for this.

[0360] Next, on the auxiliary layer of the above-obtained sealant film, a transparent vapor deposition layer (aluminum vapor deposition layer) composed of aluminum having a thickness of 40 nm was formed using a vacuum vapor deposition device based on an electron beam heating method, and a laminate was produced.

[0361] (Example F10) To the hopper for extruding the sealant layer, a block PP (manufactured by Japan Polypropylene, product name "NOVATEC PPBC6DRF") to which 6000 ppm of an antiblocking agent (manufactured by Prime Polymer, product name "EAZ-20") was added by dry blending was put, and a sealant film was produced in the same manner as in Example F2, except for this.

[0362] Next, on the auxiliary layer of the above-obtained sealant film, a transparent vapor deposition layer (aluminum vapor deposition layer) composed of aluminum having a thickness of 40 nm was formed using a vacuum vapor deposition device based on an electron beam heating method, and a laminate was produced.

[0363] (Example F11) A sealant film was produced in the same manner as in Example F1, except that the LLDPE to which 6000 ppm of an anti-blocking agent (manufactured by Prime Polymer, product name "EAZ-20") was added by dry blending was used for the sealant layer. Next, an aluminum evaporation layer was formed on the sealant layer of the thus-obtained sealant film in the same manner as in Example F1, and a laminate was produced.

[0364] Next, a transparent evaporation layer (aluminum evaporation layer) composed of aluminum having a thickness of 40 nm was formed on the auxiliary layer of the thus-obtained sealant film using a vacuum evaporation device based on an electron beam heating method, and a laminate was produced.

[0365] (Example F12) A sealant film was produced in the same manner as in Example F11, except that EVOH (manufactured by Kuraray, product name "EVAL L171B") was used instead of LLDPE for the auxiliary layer. Next, an aluminum evaporation layer was formed on the auxiliary layer of the thus-obtained sealant film in the same manner as in Example F1, and a laminate was produced.

[0366] Next, a transparent evaporation layer (aluminum evaporation layer) composed of aluminum having a thickness of 40 nm was formed on the auxiliary layer of the thus-obtained sealant film using a vacuum evaporation device based on an electron beam heating method, and a laminate was produced.

[0367] (Comparative Example F1) A sealant film was produced in the same manner as in Example 1, except that no anti-blocking agent was added to the sealant layer. Next, an aluminum evaporation layer was formed on the sealant film in the same manner as in Example F1, and a laminate was produced.

[0368] (Comparative Example F2) A sealant film was produced in the same manner as in Example F1, except that the amount of extrusion of each layer was adjusted (the screw rotation speed at the time of extrusion of the recycled material-containing layer was changed to 51 rpm) to produce a recycled material-containing layer having a thickness of 95 μm and a sealant layer having a thickness of 5 μm. Next, an aluminum evaporation layer was formed on the sealant film in the same manner as in Example F1, and a laminate was produced.

[0369] (Comparative Example F3) Recycled material 2 was added to the hopper containing the recycled material layer. No anti-blocking agent was added to the sealant layer. The extrusion rate of each layer was adjusted (the screw speed during extrusion of the recycled material layer was changed to 43 rpm) to produce an 80 μm thick recycled material layer and a 20 μm thick sealant layer. Otherwise, a sealant film was fabricated in the same manner as in Example F1. Next, an aluminum vapor-deposited layer was formed on this sealant film in the same manner as in Example F1 to create a laminate.

[0370] (Comparative Example F4) Recycled material 2 was fed into the hopper containing the recycled material layer. The extrusion rate of each layer was adjusted (the screw speed during extrusion of the recycled material layer was changed to 52 rpm) to produce a 98 μm thick recycled material layer and a 2 μm thick sealant layer. Otherwise, a sealant film was made in the same manner as in Example F1. Next, an aluminum vapor deposition layer was formed on the sealant film in the same manner as in Example F1 to create a laminate.

[0371] (Comparative Example F5) Except that the amount of anti-blocking agent added was changed to 600 ppm, the sealant film was prepared in the same manner as in Example F1. Then, an aluminum vapor-deposited layer was formed on the sealant film in the same manner as in Example F1 to form a laminate.

[0372] <Evaluation of Sealant Film> The surface roughness of the sealant layer, the reliability of sealing, the evaluation of the protrusions of the laminate, and the evaluation of film-forming properties were performed in the same manner as described above.

[0373] <Evaluation of Layered Structures> The gas barrier properties of the laminate are evaluated as follows.

[0374] (Gas barrier properties) A water vapor transmission rate measuring device manufactured by MOCON (product name: PERMATRAN3 / 34G, measurement conditions: 40℃-90%RH, unit: g / (m²)) was used. 2 The water vapor transmission rate (WVTR) of the laminates obtained in each embodiment and comparative example was evaluated. The measurement method was based on JIS K-7129-2:2019. The water vapor barrier property was less than 3 g / (m²). 2 The rating was "◎" for 3g / (m²) days. 2 ·day) or more and 5g / (m 2 ·day) or less is rated as "○", greater than 5g / (m 2 The evaluation for day is "×".

[0375] As shown in Tables 13 and 14, it was confirmed that the sealant films and laminates of Examples F1 to F12 sufficiently had reliability at heat sealing and film forming properties while containing recycled materials, and the gas barrier properties were also excellent. Therefore, according to the present application, material recycling of recycled materials containing two or more kinds of resins can be achieved in laminates, packaging materials.

[0376] Preparation of sealant film and laminate G (Example G1) A recycled material 1 was charged into a hopper for extruding a recycled material-containing layer, and LLDPE (manufactured by Prime Polymer Co., Ltd., product name "Evolue SP1540") to which 6000 ppm of an anti-blocking agent (manufactured by Prime Polymer Co., Ltd., product name "EAZ-20") was added by dry blending was charged into a hopper for extruding a sealant layer, and a recycled material-containing layer having a thickness of 30 μm and a sealant layer having a thickness of 70 μm were formed by co-extrusion molding using a single-screw multilayer extruder, to prepare a sealant film. In addition, the screw rotation speed at the time of extruding the recycled material-containing layer was 16 rpm, and a mechanism that makes it difficult to apply a tensile stress was formed by avoiding the narrowing of the flow path before the T die, and the molten resin was cooled by a cooling roll provided with a matte style of concave-convex shape (surface roughness Rz: 6 μm) using an air knife and sandblasting processing.

[0377] Next, on a silicon vapor-deposited PET film (convex plate holding Co., Ltd., "GL-RD", film thickness of the PET film: 12 μm, silicon vapor deposition), a solventless adhesive "TSN-4864A / TSN-4864B3" (manufactured by Oriental Morton Co., Ltd.) (a mixture of a main agent "TSN-4864A" and a curing agent "TSN-4864B3" at a weight ratio of 1:1) was applied in an amount of 2 g / m 2 in the manner of a roll coater, and the recycled material-containing layer of the above sealant film was laminated to prepare a laminate.

[0378] (Example G2) The extrusion amount of each layer was adjusted (the screw rotation speed at the time of extruding the recycled material-containing layer was changed to 43 rpm) to manufacture a recycled material-containing layer having a thickness of 80 μm and a sealant layer having a thickness of 20 μm, and a sealant film was prepared in the same manner as in Example G1 except for this. Next, a laminate was prepared in the same manner as in Example G1 except for using this sealant film.

[0379] (Example G3) The sealant film was produced in the same manner as in Example G1, except that the thickness of the recycled material-containing layer was adjusted to 90 μm and the thickness of the sealant layer was adjusted to 10 μm. Then, the laminate was produced in the same manner as in Example G1, except that the sealant film was used.

[0380] (Example G4) The sealant film was produced in the same manner as in Example G1, except that the cooling of the molten resin was performed using a chill roll provided with a matte-style concavo-convex shape (surface roughness Rz: 6 μm) by sandblasting processing under a pressure of 1.4 MPa, and the thickness of the recycled material-containing layer was adjusted to 90 μm and the thickness of the sealant layer was adjusted to 10 μm. Then, the laminate was produced in the same manner as in Example G1, except that the sealant film was used.

[0381] (Example G5) The sealant film was produced in the same manner as in Example G1, except that the recycled material 2 was fed to the hopper for extruding the recycled material-containing layer, and the thickness of the recycled material-containing layer was adjusted to 80 μm and the thickness of the sealant layer was adjusted to 20 μm. Then, the laminate was produced in the same manner as in Example G1, except that the sealant film was used.

[0382] (Example G6) The sealant film was produced in the same manner as in Example G5, except that the thickness of the recycled material-containing layer was adjusted to 90 μm and the thickness of the sealant layer was adjusted to 10 μm. Then, the laminate was produced in the same manner as in Example G1, except that the sealant film was used.

[0383] (Example G7) The sealant film was produced in the same manner as in Example G5, except that the thickness of the recycled material-containing layer was adjusted to 95 μm and the thickness of the sealant layer was adjusted to 5 μm. Then, the laminate was produced in the same manner as in Example G1, except that the sealant film was used.

[0384] (Example G8) A cooling roll provided with a matte style of concave-convex shape (surface roughness Rz: 6 μm) by sandblasting processing was used, and the molten resin was cooled under a pressure of 1.4 MPa using a pinch roll (material: fluorine resin), and the extrusion amount of each layer was adjusted (the screw rotation speed was changed to 48 rpm when the layer containing recycled material was extruded), to produce a layer containing recycled material having a thickness of 90 μm and a sealant layer having a thickness of 10 μm, and a sealant film was produced in the same manner as in Example G5, except for this. Then, a laminate was produced in the same manner as in Example G1, except for using this sealant film.

[0385] (Example G9) A sealant film was produced by extruding an auxiliary layer having a thickness of 20 μm, a layer containing recycled material having a thickness of 80 μm, and a sealant layer having a thickness of 20 μm using a single-screw multilayer extruder by co-extrusion molding, using recycled material 1 for the hopper for extruding the layer containing recycled material, LLDPE (product name "Evolue SP1540" manufactured by Prime Polymer Co., Ltd.) to which 6000 ppm of an anti-blocking agent (product name "EAZ-20" manufactured by Prime Polymer Co., Ltd.) was added by dry blending for the hopper for extruding the sealant layer, and LLDPE (product name "Evolue SP2040" manufactured by Prime Polymer Co., Ltd.) for the hopper for extruding the auxiliary layer. Furthermore, the screw rotation speed when the layer containing recycled material was extruded was 43 rpm, the narrowing of the flow path before the T die was avoided as much as possible, a mechanism that made it difficult to apply a tensile stress was formed, and the molten resin was cooled by a gas knife and a cooling roll provided with a matte style of concave-convex shape (surface roughness Rz: 6 μm) by sandblasting processing. Then, a laminate was produced in the same manner as in Example G1, except for using this sealant film.

[0386] (Example G10) A sealant film was produced in the same manner as in Example G2, except that recycled material 1 and LLDPE (product name "Evolue SP2040" manufactured by Prime Polymer Co., Ltd.) were put into the hopper for extruding the layer containing recycled material in a weight ratio of 1:1. Then, a laminate was produced in the same manner as in Example G1, except for using this sealant film.

[0387] (Example G11) To a hopper for an extrusion sealant layer, block PP (manufactured by Japan Polypropylene Corporation, product name "NOVATEC PPBC6DRF") to which 6000 ppm of an anti-blocking agent (manufactured by Prime Polymer, product name "EAZ-20") was added by dry blending was charged, and a sealant film was produced in the same manner as in Example G2, except that. Subsequently, a laminate was produced in the same manner as in Example Gl, except that the sealant film was used.

[0388] (Example G12) A sealant film was produced in the same manner as in Example Gl. Subsequently, a laminate was produced in the same manner as in Example Gl, except that the sealant film was used, and a solvent-type adhesive agent "Takelac A626 (manufactured by Mitsui Chemicals, Inc.)" and "Takenate A-50 (manufactured by Mitsui Chemicals, Inc.)", which contain organic solvents, were mixed at a weight ratio of 8: 1 instead of the solventless adhesive agent.

[0389] (Example G13) A sealant film was produced in the same manner as in Example G2. Subsequently, a laminate was produced in the same manner as in Example Gl, except that the sealant film was used, and a solvent-type adhesive agent "Takelac A626 (manufactured by Mitsui Chemicals, Inc.)" and "Takenate A-50 (manufactured by Mitsui Chemicals, Inc.)", which contain organic solvents, were mixed at a weight ratio of 8: 1 instead of the solventless adhesive agent.

[0390] (Example G14) A sealant film was produced in the same manner as in Example G3. Subsequently, a laminate was produced in the same manner as in Example Gl, except that the sealant film was used, and a solvent-type adhesive agent "Takelac A626 (manufactured by Mitsui Chemicals, Inc.)" and "Takenate A-50 (manufactured by Mitsui Chemicals, Inc.)", which contain organic solvents, were mixed at a weight ratio of 8: 1 instead of the solventless adhesive agent.

[0391] (Example G15) A sealant film was produced in the same manner as in Example G4. Subsequently, a laminate was produced in the same manner as in Example Gl, except that the sealant film was used, and a solvent-type adhesive agent "Takelac A626 (manufactured by Mitsui Chemicals, Inc.)" and "Takenate A-50 (manufactured by Mitsui Chemicals, Inc.)", which contain organic solvents, were mixed at a weight ratio of 8: 1 instead of the solventless adhesive agent.

[0392] (Example G16) A sealant film was produced in the same manner as in Example G5. Next, using the sealant film, instead of the solventless adhesive, a reagent in which solvent-type adhesives "Takelac A626 (manufactured by Mitsui Chemicals, Inc.)" and "Takenate A-50 (manufactured by Mitsui Chemicals, Inc.)" containing an organic solvent were mixed at a weight ratio of 8: 1 was used, and a laminate was produced in the same manner as in Example Gl, except for this.

[0393] (Example G17) A sealant film was produced in the same manner as in Example G6. Next, using the sealant film, instead of the solventless adhesive, a reagent in which solvent-type adhesives "Takelac A626 (manufactured by Mitsui Chemicals, Inc.)" and "Takenate A-50 (manufactured by Mitsui Chemicals, Inc.)" containing an organic solvent were mixed at a weight ratio of 8: 1 was used, and a laminate was produced in the same manner as in Example Gl, except for this.

[0394] (Example G18) A sealant film was produced in the same manner as in Example G7. Next, using the sealant film, instead of the solventless adhesive, a reagent in which solvent-type adhesives "Takelac A626 (manufactured by Mitsui Chemicals, Inc.)" and "Takenate A-50 (manufactured by Mitsui Chemicals, Inc.)" containing an organic solvent were mixed at a weight ratio of 8: 1 was used, and a laminate was produced in the same manner as in Example Gl, except for this.

[0395] (Example G19) A sealant film was produced in the same manner as in Example G8. Next, using the sealant film, instead of the solventless adhesive, a reagent in which solvent-type adhesives "Takelac A626 (manufactured by Mitsui Chemicals, Inc.)" and "Takenate A-50 (manufactured by Mitsui Chemicals, Inc.)" containing an organic solvent were mixed at a weight ratio of 8: 1 was used, and a laminate was produced in the same manner as in Example Gl, except for this.

[0396] (Example G20) A sealant film was produced in the same manner as in Example G9. Next, using the sealant film, instead of the solventless adhesive, a reagent in which solvent-type adhesives "Takelac A626 (manufactured by Mitsui Chemicals, Inc.)" and "Takenate A-50 (manufactured by Mitsui Chemicals, Inc.)" containing an organic solvent were mixed at a weight ratio of 8: 1 was used, and a laminate was produced in the same manner as in Example Gl, except for this.

[0397] (Comparative Example G1) A sealant film was produced in the same manner as in Example Gl, except that no anti-blocking agent was added to the sealant layer. Next, a laminate was produced in the same manner as in Example Gl, except that the sealant film was used.

[0398] (Comparative Example G2) The amount of extrusion of each layer was adjusted (the screw rotation speed at the time of extruding the layer containing recycled material was changed to 51 rpm) to produce a layer containing recycled material having a thickness of 95 μm and a sealant layer having a thickness of 5 μm, and a sealant film was produced in the same manner as in Example G1, except for this. Subsequently, a laminate was produced in the same manner as in Example G1, except for using this sealant film.

[0399] (Comparative Example G3) The recycled material 2 was charged into the hopper for extruding the layer containing recycled material, no anti-blocking agent was added to the sealant layer, the amount of extrusion of each layer was adjusted (the screw rotation speed at the time of extruding the layer containing recycled material was changed to 43 rpm) to produce a layer containing recycled material having a thickness of 80 μm and a sealant layer having a thickness of 20 μm, and a sealant film was produced in the same manner as in Example G1, except for this. Subsequently, a laminate was produced in the same manner as in Example G1, except for using this sealant film.

[0400] (Comparative Example G4) The recycled material 2 was charged into the hopper for extruding the layer containing recycled material, the amount of extrusion of each layer was adjusted (the screw rotation speed at the time of extruding the layer containing recycled material was changed to 52 rpm) to produce a layer containing recycled material having a thickness of 98 μm and a sealant layer having a thickness of 2 μm, and a sealant film was produced in the same manner as in Example G1, except for this. Subsequently, a laminate was produced in the same manner as in Example G1, except for using this sealant film.

[0401] (Comparative Example G5) A sealant film was produced in the same manner as in Example G1, except for changing the amount of addition of the anti-blocking agent to 600 ppm. Subsequently, a laminate was produced in the same manner as in Example G1, except for using this sealant film.

[0402] <Sealant film> The measurement of the surface roughness of the sealant layer, the reliability evaluation at the time of sealing, the evaluation of the protrusions of the laminate layer, and the evaluation of the film forming property were performed in the same manner as described above.

[0403] <Appearance evaluation of the laminate (packaging material)> The laminate (packaging material) produced in each of the examples and comparative examples was evaluated for appearance: bubbles as follows.

[0404] (Appearance: bubbles) Each laminate obtained in each of the examples and comparative examples was cut into a square of 100 mm, and evaluated based on the following evaluation criteria.

[0405] [Evaluation criteria] ◎: Number of absence of bubbles having a diameter of 0.1 mm or more O: Presence of bubbles having a diameter of 0.1 mm or more and less than 0.5 mm Δ: Presence of bubbles having a diameter of 0.5 mm or more and less than 1 mm X: Presence of bubbles having a diameter of 1 mm or more As shown in Tables 16 to 19, it was confirmed that the sealant films and laminates of Examples G1 to G20 sufficiently had reliability at heat sealing and film forming property while containing recycled materials, and the appearance was also excellent. Therefore, according to the present application, material recycling of recycled materials containing two or more kinds of resins can be achieved in laminates, packaging materials.

[0406] Explanation of Reference Signs 1a, 1b sealant film, 2 recycled material-containing layer, 3 sealant layer, 4 auxiliary layer, 5 adhesive layer, 6 base material film, 7 printed layer, 10a, 10b, 10c, 10d laminate, 12 gas barrier layer, 50 coagulum, 100, 101, 102 packaging material.

Claims

1. A sealant film comprising a recycled material-containing layer containing a recycled material containing two or more resins, and a sealant layer laminated on one main surface of the recycled material-containing layer, wherein an arithmetic surface roughness of a surface of the sealant layer opposite to the recycled material-containing layer side is 0.5 μm or more and 5 μm or less. The arithmetic surface roughness of the surface of the sealant layer opposite to the recycled material-containing layer side is 0.5 μm or more and 5 μm or less.

2. The encapsulant film of claim 1, wherein, At least one of the recycled material-containing layer and the sealant layer contains a chemically recycled resin.

3. The encapsulant film of claim 1, wherein, The sealant film contains a biomass-derived polyethylene-based resin.

4. The encapsulant film of claim 1, wherein, The sealant film is subjected to electron beam irradiation treatment.

5. The encapsulant film of claim 1, wherein, The sealant film contains inorganic particles.

6. The encapsulant film of claim 1, wherein, A thickness of the sealant layer is 5 μm or more and 70 μm or less.

7. The encapsulant film of claim 1, wherein, A maximum height H of a convex portion on the surface of the sealant layer is 0.5 μm or more and 10 μm or less, and a ratio of a width W at half the maximum height H to the maximum height H is 20 or less in terms of W / H.

8. The encapsulant film of claim 1, wherein, A resin having the largest content ratio among the two or more resins contained in the recycled material is a polyethylene-based resin or a polypropylene-based resin.

9. The sealant film according to claim 1, further comprising an auxiliary layer laminated on the other main surface of the recycled material-containing layer.

10. The encapsulant film of claim 9, wherein, The auxiliary layer contains a pure resin of the same kind as the resin having the largest content ratio in the recycled material-containing layer.

11. A laminate comprising the sealant film according to any one of claims 1 to 10, and a gas barrier layer provided on a surface of the sealant film opposite to the sealant layer side.

12. A laminate comprising, in this order, the sealant film according to any one of claims 1 to 10, an adhesive layer, and a base material film.

13. A packaging material comprising the sealant film according to any one of claims 1 to 10.

14. The packaging material of claim 13, wherein, A content of plastic material contained in the recycled material is 10% by mass or more, based on a total amount of plastic material in the packaging material.

15. A packaging bag produced from the packaging material according to claim 13.

16. A packaging bag produced from the packaging material according to claim 14.

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