Laminate, packaging material and packaging bag

Abstract

To provide a laminate having sufficient lamination suitability, while containing a recycled material containing two or more kinds of resins.SOLUTION: A laminate 1 includes a first layer 11 containing a virgin resin, a second layer 13 containing a virgin resin, and an intermediate layer 12 which is provided between the first layer 11 and the second layer 13 and contains a recycled material containing two or more kinds of resins, wherein the film thickness range of the laminate 1 is 150 μm or less.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a laminate, a packaging material, and a packaging bag. [Background technology]

[0002] In general, plastic films have properties such as being lightweight, chemically stable, easy to process, flexible and strong, and capable of mass production, and are used in a variety of applications. Applications are diverse, including, for example, packaging materials for packaging food and medicine, infusion packs, shopping bags, posters, tapes, optical films for LCD televisions, protective films, window films for attaching to windows, vinyl greenhouses, building materials, and the like. Specific materials include, for example, thermoplastic resins such as polyethylene, polypropylene, polystyrene, acrylic polymethyl methacrylate, polycarbonate, polyamide, polyethylene terephthalate, and polybutylene terephthalate, and thermosetting resins such as epoxy resin, polyurethane, and polyimide.

[0003] Appropriate plastic materials are selected depending on the application, and multiple types of plastic materials are layered to form a laminate. In addition, multiple plastic materials can be mixed in one layer to make up for the shortcomings of a single material. There are also laminates that contain aluminum foil to provide light blocking properties, a printed layer with an ink pattern to give the product a design, and an adhesive layer to bond incompatible plastic materials together.

[0004] Recycling of plastic products is expected to be a part of efforts to address environmental issues, and various recycling methods are being considered. For example, technology has been established for material recycling, in which collected PET bottles are washed and crushed for reuse as raw materials, and chemical recycling, in which the products are converted into monomers.

[0005] For example, Patent Document 1 below discloses a technology related to a sealant film containing recycled polyethylene resin, and describes that the recycled polyethylene is recovered from used polyethylene molded bodies or waste materials from the production thereof, and that the recycled polyethylene can be obtained through various processes such as crushing, washing, filtration, and extraction. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2022 / 124229 Summary of the Invention [Problem to be solved by the invention]

[0007] Patent Document 1 proposes a sealant film in which an intermediate layer containing recycled polyethylene is placed between two virgin polyethylene layers made from virgin materials that have never been processed, and the film is evaluated for its deodorizing and concealing properties, but does not disclose the specific structure or evaluation of a sealant film that uses plastic films composed of various materials as recycled materials.

[0008] Recycled materials may contain different types of resins. From the viewpoint of the freedom of choice of recycled materials, the present inventors have considered recycling recycled materials containing multiple types of resins as raw materials for sealant films, and have found the following problems. A sealant film used in a packaging material may be laminated with a base film for supplementing mechanical strength, or a base film provided with a printed layer, but it has become clear that a film containing recycled materials may have defective parts where the adhesive does not adhere when dry lamination is performed using an adhesive. Such defective parts may cause the packaging material to break.

[0009] The present invention has been made in consideration of the above circumstances, and aims to provide a laminate that contains recycled materials containing two or more types of resins and has sufficient lamination suitability, as well as a packaging material and a packaging bag using the same. [Means for solving the problem]

[0010] In order to solve the above problem, the present inventors have investigated the cause of defective parts where the adhesive does not adhere, and have found that in a layer containing recycled material containing two or more resins, aggregates may be formed by components other than the resin with the largest mass ratio, and when excessively large protrusions are formed on the surface of a film containing recycled material by these aggregates, defective parts where the adhesive does not locally exist between the laminate layer and the substrate during dry lamination are generated. Based on this knowledge, the present inventors have conducted further investigations and found that the above problem can be solved by sandwiching a layer containing recycled material between two resin layers to form a laminate and setting the thickness range of this laminate to a specific value or less.

[0011] One aspect of the present invention relates to the following [1] to [8].

[0012] [1] A laminate comprising a first layer, a second layer, and an intermediate layer disposed between the first layer and the second layer, wherein the first layer and the second layer contain virgin resin, the intermediate layer contains a recycled material containing two or more types of resin, and the laminate has a thickness range of 150 μm or less. [2] The laminate described in [1], wherein the content of the resin having the highest mass ratio in the recycled material is 67 mass% or more based on the total mass of the recycled material. [3] The laminate according to [1] or [2], wherein the thickness of each of the first layer and the second layer is 5 μm or more and 100 μm or less. [4] The laminate according to any one of [1] to [3], wherein the resin having the maximum mass ratio in the recycled material is a polyolefin resin. [5] The laminate according to any one of [1] to [4], wherein the first layer and the second layer contain the same type of virgin resin as the resin having the greatest mass ratio in the recycled material. [6] The laminate according to any one of [1] to [5], wherein the recycled material contains at least one of a polyamide resin and a polyester resin as a resin that does not have the largest mass proportion in the recycled material. [7] The laminate according to any one of [1] to [6], wherein the laminate has an impact resistance of 9 J / mm or more at 23° C. [8] A packaging material comprising the laminate according to any one of [1] to [7]. [9] The packaging material described in [8], wherein the recycled material is contained in an amount of 10 mass% or more, calculated based on the total amount of plastic material in the packaging material, in terms of the mass of plastic material.

[10] A packaging bag made from the packaging material described in [8] or [9]. Effect of the Invention

[0013] According to the present invention, it is possible to provide a laminate that contains recycled materials containing two or more types of resins and has sufficient lamination suitability, as well as a packaging material and a packaging bag using the same.

[0014] According to the laminate described in [1] above, since the fluctuation width of the film thickness is 150 μm or less, it is possible to sufficiently suppress the occurrence of defective parts where the adhesive does not adhere when dry laminating a substrate to the laminate via an adhesive. Therefore, the laminate described in [1] can have sufficient lamination suitability while containing a recycled material containing two or more types of resin.

[0015] According to the laminate described in [2] above, since it is possible to reduce the size of the aggregates formed by components other than the resin having the largest mass ratio, it is easy to keep the film thickness fluctuation range to 150 μm or less while increasing the content of recycled material in the laminate, and it is possible to improve the freedom of selection of recycled materials and to achieve lamination suitability at the same time. In addition, according to the laminate described in [2], since it is possible to reduce the size of the aggregates in the layer containing recycled material, it is possible to suppress the deterioration of film formability and to easily ensure the peel strength between layers in the laminate. [Brief description of the drawings]

[0016] [Figure 1] 1 is a schematic cross-sectional view showing one embodiment of a laminate according to the present invention. [Diagram 2] 1 is a schematic cross-sectional view showing one embodiment of a packaging material according to the present invention. [Diagram 3] FIG. 2 is a schematic cross-sectional view for explaining a method for evaluating peel strength. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, the embodiments of the present invention will be described in detail. Note that Figs. 1-2 are schematic diagrams, and the size and shape of each part are appropriately exaggerated to facilitate understanding. The embodiments shown below are merely examples of configurations for embodying the technical idea of ​​the present invention, and the technical idea of ​​the present invention is not limited to the materials, shapes, structures, etc. of the components described below. The technical idea of ​​the present invention can be modified in various ways within the technical scope defined by the claims described in the claims.

[0018] <Laminate> The laminate of this embodiment includes a first layer containing a virgin resin, a second layer containing a virgin resin, and an intermediate layer containing a recycled material containing two or more types of resins, which is provided between the first and second layers. When the laminate of this embodiment is used as a packaging material, for example, the second layer can be an inner layer and the first layer can be an outer layer. In this case, a base film or the like can be further laminated on the first layer by dry lamination via an adhesive.

[0019] Fig. 1 is a schematic cross-sectional view showing one embodiment of a laminate. The laminate 1 shown in Fig. 1 has a structure in which a first layer 11, an intermediate layer 12, and a second layer 13 are laminated in this order.

[0020] <Middle Class> The recycled materials contained in the middle layer can be called post-industrial recycled (PIR), which are defective products that cannot be made into products discharged from factories, scraps generated during the manufacturing process, and plastic products used for transportation and packaging, and called post-consumer recycled (PCR), which are collected from the market and include bottles and packaging bags for beverages, detergents, and seasonings, food containers for bento boxes and instant noodles, packaging bags for food and garbage bags, and plastic products such as hangers, stationery, daily necessities, home appliances, and toys.

[0021] In the laminate of the present embodiment, from the viewpoint of material recycling of plastic films, a laminate (packaging material) made by bonding together a plurality of types of resin sheets, a packaging bag made by making a bag from the laminate, a laminate (packaging material) made by bonding together the same types of resin sheets, or a packaging bag made by making a bag from the laminate, or a mixture of these may be used. Examples of packaging bags include refill pouches for toiletries.

[0022] The recycled material contained in the intermediate layer contains two or more resins. In the case where the resin contained in the recycled material is a single resin, there are a method of using a material recycled from a packaging bag made of a single material, and a method of refining a single resin from a material containing multiple resins. However, the former method has limited uses for packaging bags made of a single material, making it difficult to collect the amount required for recycling, and the latter method requires energy and cost for refining, which tends to deteriorate recyclability. By using a recycled material containing two or more resins, the above problems can be solved and the recyclability can be improved. Examples of the two or more resins contained in the recycled material include thermoplastic resins, thermosetting resins, and their cured products (including crosslinked products). In addition, the two or more resins include, for example, resin components (such as thermosetting resins) that constitute adhesives and their cured products.

[0023] Examples of the thermoplastic resin include polyolefin resin, acrylic resin, polycarbonate resin, polyester resin, polyamide resin, etc. Examples of the thermosetting resin include epoxy resin, polyurethane resin, polyimide resin, etc.

[0024] Examples of polyolefin-based resins include polyethylene-based resins such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), and ethylene-α-olefin copolymers, as well as polypropylene-based resins such as homopolypropylene (PP), block polypropylene, random polypropylene, and propylene-α-olefin copolymers.

[0025] Examples of polyester resins include polyethylene terephthalate, polybutylene terephthalate, and polylactic acid.

[0026] An example of the polyamide resin is nylon 6.

[0027] The two or more resins may include a first resin that has the largest mass ratio in the recycled material and a second resin that is incompatible with the first resin or that may form aggregates in the first resin. The recycled material may include one type of resin as the second resin, or may include two or more types of resin. The type of resin included in the recycled material can be confirmed by a micro infrared spectrophotometer or the like.

[0028] The first resin and the second resin may be the following combinations. (a) Thermoplastic resins, thermosetting resins and their hardened products (b) Hydrocarbon-based resins and heteroatom-containing resins (c) A resin that dissolves in a specified solvent and a resin that does not dissolve in the specified solvent.

[0029] Examples of the hydrocarbon resin in (b) include polyolefin resins and polystyrene resins, and examples of the heteroatom-containing resin include acrylic resins, polyester resins, and polyamide resins.

[0030] The predetermined solvent in (c) may be an aromatic hydrocarbon, a chlorinated hydrocarbon, etc. The resin that dissolves in the predetermined solvent may be an uncrosslinked resin, etc. The resin that does not dissolve in the predetermined solvent may be a crosslinked resin, a cured thermosetting resin, etc.

[0031] The first resin having the largest mass ratio in the recycled material may be a polyethylene resin or a polypropylene resin. In this case, packaging bags for pouch products and the like can be easily recycled. When the first resin is a polyethylene resin or a polypropylene resin, the second resin may be at least one of a polyester resin, a polyamide resin, and a resin component constituting an adhesive and its cured product.

[0032] The content of the first resin in the recycled material may be 67% by mass or more and less than 100% by mass, 75% by mass or more and less than 95% by mass, or 80% by mass or more and less than 90% by mass, based on the total mass of the recycled material. If the content of the first resin in the recycled material is less than 67% by mass, a problem is likely to occur in which components other than the first resin, which has the largest mass ratio in the recycled material (e.g., the second resin), form aggregates in the intermediate layer.

[0033] The total content of the second resin in the recycled material may be more than 0% by mass and not more than 33% by mass, 5% by mass or more and not more than 25% by mass, or 10% by mass or more and not more than 20% by mass, based on the total mass of the recycled material. When the total content of the second resin is within the above range, aggregates of the second resin are unlikely to be formed, and the second resin is easily dispersed in the first resin.

[0034] The total content of the components other than the first resin (the second resin and the components other than the resin) that have the maximum mass ratio in the recycled material may be more than 0 mass% and not more than 33 mass%, may be 5 mass% or more and not more than 25 mass%, or may be 10 mass% or more and not more than 20 mass%, based on the total mass of the recycled material. When the total content of the components other than the first resin is within the above range, the components other than the first resin are easily dispersed in the first resin.

[0035] The content of the recycled material in the intermediate layer may be 13% by mass or more, 33% by mass or more, 50% by mass or more, 80% by mass or more, or 100% by mass based on the total mass of the intermediate layer. If the content of the recycled material is less than 13% by mass, it is difficult to make the content of the recycled material (converted into plastic material) 10% by mass or more based on the total amount of plastic material in the packaging material, which is not preferable from the viewpoint of recyclability. Note that, when the intermediate layer is made of only recycled material (the content of the recycled material is 100% by mass), the content of the first resin, the total content of the second resin, and the total content of the components other than the first resin in the above-mentioned recycled material can be read as values ​​based on the total mass of the intermediate layer.

[0036] The resin having the maximum mass ratio in the intermediate layer may be the same as the resin having the maximum mass ratio in the recycled material. Such a resin may be, for example, at least one polyethylene resin selected from the group consisting of low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), and ethylene-α-olefin copolymer, or at least one polypropylene resin selected from the group consisting of homopolypropylene (PP), block polypropylene, random polypropylene, and propylene-α-olefin copolymer.

[0037] The intermediate layer may contain a virgin material such as a virgin resin. The virgin material may be blended so that the resin with the maximum mass ratio in the recycled material is the same as the resin with the maximum mass ratio in the intermediate layer. As the virgin material, for example, the same polyolefin resin as described above can be used, and it may be at least one polyethylene resin selected from the group consisting of low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), and ethylene-α-olefin copolymer, or at least one polypropylene resin selected from the group consisting of homopolypropylene (PP), block polypropylene, random polypropylene, and propylene-α-olefin copolymer.

[0038] The intermediate layer may contain aggregates derived from, for example, the second resin, but from the viewpoint of the impact resistance, lamination suitability, and peel strength of the laminate, it is preferable that the aggregates are as small as possible. For example, the following means can be used to reduce the size of the aggregates in the intermediate layer. (a) Decrease the proportion of recycled materials in the middle layer (b) Increasing the content of the first resin in the recycled material. (c) When extruding the middle layer, increase the screw rotation speed. (d) Recycled materials are pelletized using a twin-screw extruder or mixed with virgin resin to form a masterbatch. (e) Adding a compatibilizer to the recycled material

[0039] The thickness of the intermediate layer may be 150 μm or less. In this case, it is easy to suppress the cost. When the thickness of the intermediate layer varies, the maximum thickness of the intermediate layer may be 150 μm or less for the same reason as above.

[0040] <First and second layers> As the material for forming the first layer and the second layer, a material having suitable flexibility and good processability, such as suitability for processing by an extruder, such as a thermoplastic resin, can be used. Examples of such materials include low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), and polypropylene having a homopolymer, random copolymer, or block copolymer, ethylene-vinyl acetate copolymer obtained by copolymerizing olefin such as low-density polyethylene (LDPE) with vinyl acetate, ethylene-methyl acrylate copolymer (EMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-butyl acrylate copolymer (EBA), and ethylene-methacrylic acid copolymer (EMAA) obtained by modifying the side chain of olefin, etc. These may be used alone or in combination of two or more kinds.

[0041] From the viewpoint of adhesion to the intermediate layer, the first layer and the second layer preferably contain the same type of resin as the resin having the largest mass ratio in the intermediate layer. For example, when the resin having the largest mass ratio in the intermediate layer is a polyethylene-based resin, the first layer and the second layer may contain a polyethylene-based resin, or the polyethylene-based resin may be the main component (for example, the content in the first layer and the second layer is 90% by mass or more). When the resin having the largest mass ratio in the intermediate layer is a polypropylene-based resin, the first layer and the second layer may contain a polypropylene-based resin, or the polypropylene-based resin may be the main component (for example, the content in the first layer and the second layer is 90% by mass or more).

[0042] The first layer and the second layer may contain the above-mentioned resin as a virgin resin. Alternatively, the first layer and the second layer may not contain recycled materials. In this case, it is possible to suppress the transfer of low molecular weight components contained in the recycled materials and the adverse effect on the adhesion with the adhesive layer.

[0043] The thickness of the first layer and the second layer may be 5 μm or more and 100 μm or less. In this case, it is easy to suppress the occurrence of excessive unevenness on the surface of the laminate due to the aggregate contained in the intermediate layer, and it is easy to prevent excessive cost increase and increase the content rate of recycled materials in the laminate. This makes it possible to more effectively realize material recycling of recycled materials containing two or more types of resins in the laminate. The thickness of the first layer and the second layer may be 20 μm or more and 80 μm or less, 30 μm or more and 70 μm or less, or 50 μm or more and 65 μm or less. When the thickness of the first layer and the second layer varies, the maximum thickness of the first layer and the second layer may be within the above range for the same reason as above.

[0044] The thickness and maximum thickness of each layer constituting the laminate may be measured in the width direction of the laminate (direction perpendicular to the flow direction during film production).

[0045] The first layer, the second layer and the intermediate layer may contain additives such as compatibilizers, nucleating agents, reinforcing fillers, antioxidants, heat stabilizers, weathering agents, light stabilizers, plasticizers, UV absorbers, antistatic agents, flame retardants, flame retardant assistants, slip agents, antiblocking agents, antifogging agents, lubricants, tackifiers, pigments, dyes, dispersants, copper damage inhibitors, neutralizing agents, bubble inhibitors, weld strength improvers, natural oils, synthetic oils, waxes, etc. The additives may be used alone or in combination of two or more.

[0046] The compatibilizer may be a reactive or non-reactive compatibilizer, and examples thereof include acid-modified polyolefin resins, ethylene-vinyl acetate copolymers, ethylene-methyl methacrylate copolymers, and ethylene-vinyl alcohol copolymers.

[0047] Examples of nucleating agents and reinforcing fillers include talc, silica, clay, montmorillonite, calcium carbonate, lithium alumina carbonate, titanium oxide, metals such as aluminum, iron, silver, and copper, hydroxides such as aluminum hydroxide and magnesium hydroxide, celluloses such as cellulose microfibrils and cellulose acetate, fibrous fillers such as glass fibers, polyethylene terephthalate fibers, nylon fibers, polyethylene naphthalate fibers, aramid fibers, vinylon fibers, and polyacrylate fibers, carbons such as carbon nanotubes, and elastomers such as ethylene propylene rubber (EPR).

[0048] Examples of the antioxidant include phenol-based compounds, organic phosphite-based compounds, and thioether-based compounds.

[0049] Examples of the heat stabilizer include hindered amine compounds.

[0050] Examples of the ultraviolet absorbing agent include benzophenone-based compounds, benzotriazole-based compounds, and benzoate-based compounds.

[0051] The antistatic agent includes nonionic compounds, cationic compounds, anionic compounds, and the like.

[0052] Examples of the flame retardant include halogen-based compounds, phosphorus-based compounds, nitrogen-based compounds, inorganic compounds, boron-based compounds, silicone-based compounds, sulfur-based compounds, and red phosphorus-based compounds.

[0053] Examples of the flame retardant aid include antimony compounds, zinc compounds, bismuth compounds, magnesium hydroxide, and clay silicates.

[0054] Examples of the anti-blocking agent include acrylic particles, styrene particles, styrene acrylic particles and crosslinked products thereof, polyurethane particles, polyester particles, silicon particles, fluorine particles, copolymers thereof, zeolite, pyrophyllite, talc, smectite, vermiculite, mica, chlorite, kaolin minerals, clay compound particles such as sepiolite, silica, titanium oxide, alumina, silica alumina, zirconia, zinc oxide, strontium oxide, aluminum hydroxide, strontium carbonate, strontium chloride, strontium sulfate, strontium nitrate, strontium hydroxide, and glass particles.

[0055] The laminate of this embodiment may have an uneven shape on both main surfaces. One of the causes of the uneven shape of the laminate is an aggregate formed by a component (e.g., a second resin) other than the first resin that has the largest mass ratio in the recycled material. The uneven shape causes the film thickness of the laminate to vary, and the magnitude of this variation can be expressed as a film thickness range.

[0056] The laminate of this embodiment has a thickness range of 150 μm or less. The thickness range of the laminate is calculated by the following method. <How to calculate film thickness range> The film thickness of the laminate was measured in the width direction of the laminate (perpendicular to the flow direction during film production) using a continuous thickness measuring device (FT-A200) manufactured by Fujiwork Co., Ltd., at a measurement pitch of 0.1 mm and a measurement speed of 1.5 m / min. The maximum film thickness during measurement was designated Tmax (μm), and the minimum film thickness during measurement was designated Tmin (μm), and the film thickness range (μm) of the laminate was calculated according to the following formula (1). Film thickness range = Tmax-Tmin … (1)

[0057] When the thickness range of the laminate is 150 μm or less, it is possible to sufficiently suppress the occurrence of defective parts where the adhesive does not adhere when dry laminating the substrate to the laminate via the adhesive. The thickness range of the laminate may be 120 μm or less, 100 μm or less, 50 μm or less, or 30 μm or less. On the other hand, when the thickness range of the laminate is 1 μm or more, the friction coefficient is not too large, and it is possible to have appropriate slip properties, and blocking in which films stick to each other is unlikely to occur. From this viewpoint, the thickness range of the laminate may be 10 μm or more, or 30 μm or more.

[0058] The laminate of the present embodiment can be used as a sealant film. In this case, impact resistance, which is mainly provided by the sealant film in the packaging material, is required. The impact resistance of the laminate is preferably 9 J / mm or more, more preferably 12 J / mm, even more preferably 15 J / mm, and even more preferably 17 J / mm. When the impact resistance of the laminate is 9 J / mm or more, a packaging bag produced using the laminate as a sealant film is less likely to break when dropped.

[0059] The impact resistance of the laminate can be measured using a film impact tester equipped with a thermostatic chamber manufactured by Toyo Seiki Co., Ltd. under conditions of a temperature of 23° C., a weight of 3.0 J, and a bullet size of 1 / 2 inch.

[0060] The total thickness of the laminate may be 12 to 350 μm, 50 to 200 μm, or 100 to 160 μm. The maximum thickness of the laminate may be within the above range.

[0061] <Method of manufacturing laminate> The laminate of the present embodiment can be produced by a conventionally known method, for example, a method of extrusion laminating a film containing a recycled material formed from a resin composition constituting the intermediate layer with a resin composition constituting the first and second layers, or a method of forming the intermediate layer, the first layer, and the second layer by co-extrusion molding.

[0062] In the former method, the film containing the recycled material can be produced by melting the resin composition constituting the intermediate layer in an injection molding machine or an extrusion molding machine (e.g., a twin-screw extruder) and then forming the film in a T-die through a feed block or a multi-manifold, or by an inflation method. The recycled material can be produced by collecting, cleaning, and pulverizing various types of plastic waste material, melt molding the material in an extruder, and pelletizing the material. For extrusion lamination, an extrusion laminating machine or the like can be used.

[0063] In the latter method, for example, a multi-layer extrusion molding machine can be used to melt-knead and co-extrude the resin composition constituting the intermediate layer and the resin compositions constituting the first and second layers to produce a laminate.

[0064] The resin composition constituting the intermediate layer may contain only recycled materials, or may further contain virgin materials and additives to impart various desired properties such as viscosity adjustment, mechanical property reinforcement, etc. In addition, when the recycled material and the virgin material are mixed, they may be dry-blended in which the recycled material and the virgin material are simultaneously put into a hopper and melt-kneaded to form a film, or they may be melt-blended in which the recycled material and the virgin material are separately melt-kneaded in a twin-screw extruder to form a master batch.

[0065] From the viewpoint of reducing the size of aggregates in the intermediate layer, pelletizing using a twin-screw extruder, molding under high shear conditions, or blending an acid-modified polyolefin resin or the like as a compatibilizer may be performed.

[0066] The cooling method for the laminate can be selected according to the molding machine. For example, in the T-die method, air-cooling methods such as an air chamber, a vacuum chamber, or an air knife, or water-cooling methods such as dipping a cooling roll in a cold water pan can be used.

[0067] The laminate of the present embodiment can also be produced by a method using heat pressing. In the method using heat pressing, a flat film can be molded by compressing it between heated rolls or with a heated flat plate. The thickness of the molded product can be controlled by adjusting the compression pressure at this time. Single-layer films produced by heat pressing may be stacked and heat pressed again to laminate, or a pre-laminated flat film may be prepared and the film thickness may be adjusted by heat pressing.

[0068] The laminate may be subjected to a surface modification treatment to improve suitability for subsequent processes. For example, the surface to be laminated may be subjected to a surface modification treatment to improve printability and lamination suitability when laminating with other layers or substrate films. Examples of the surface modification treatment include a method of oxidizing the laminate surface to express functional groups, such as corona discharge treatment, plasma treatment, and frame treatment, and modification by a wet process, such as coating an easy-adhesion layer.

[0069] The method for producing the laminate is not limited to the above-mentioned method, and the laminate formed by the molding machine may be subjected to an in-line or off-line stretching treatment. In addition, there is no restriction on adding other necessary steps or additives as appropriate.

[0070] <Packaging material> The packaging material of this embodiment includes the laminate of this embodiment described above. Fig. 2 is a schematic cross-sectional view showing one embodiment of the packaging material. The packaging material 6 shown in Fig. 2 includes the laminate 1, a first base film 2 laminated on the main surface of the laminate 1 on the first layer 11 side via an adhesive layer 5, and a second base film 4 having a printed layer 3 laminated on the first base film 2 via the adhesive layer 5.

[0071] The base films 2 and 4 are not particularly limited as long as they have mechanical strength and dimensional stability, and may include plastic films, paper, nonwoven fabrics, etc. Constituent materials for the plastic films include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate, polyolefins such as polyethylene and polypropylene, polystyrene, polyamides such as 6-nylon, polycarbonates, polyacrylonitrile, polyimides, etc.

[0072] The adhesive constituting the adhesive layer is not particularly limited, but a dry lamination adhesive can be used. Examples of the dry lamination adhesive include a two-component curing urethane adhesive, a polyester urethane adhesive, a polyether urethane adhesive, an acrylic adhesive, a polyester adhesive, a polyamide adhesive, and an epoxy adhesive.

[0073] The packaging material of the present embodiment may further be provided with a gas barrier film (or a gas barrier layer). In this case, the barrier properties for protecting the packaging material from gases such as oxygen contained in the air, water vapor, and the enclosed contents can be improved. As the gas barrier film, a metal foil such as an aluminum foil, or a laminated film of a metal foil and a plastic film can be used. As the gas barrier film, a transparent deposition film having a deposition layer of an inorganic oxide or a metal on a plastic film can be used. Examples of the plastic film include those described above, and examples of the transparent deposition film include deposition films of metal oxides such as silicon oxide and aluminum oxide. In addition, as the gas barrier film, films of ethylene-vinyl alcohol copolymers, polyamide resins, polyvinylidene chloride resins, polyacrylonitrile resins, and the like can also be used. In addition, in the present embodiment, when a transparent deposition film is used as the gas barrier film, some of the substrate films and adhesive layers may not be provided.

[0074] The packaging material of the present embodiment is not limited to the configuration shown in FIG. 2 , and may be, for example, a packaging material comprising a laminate 1 and a first base film 2 laminated onto the laminate 1 via an adhesive layer 5; a packaging material comprising a laminate 1 and a first base film 2 laminated onto the laminate 1 via an adhesive layer 5, and a gas barrier layer provided on the first base film 2; or a packaging material comprising a laminate 1 and a first base film 2 laminated onto the laminate 1 via an adhesive layer 5, and two or more functional layers, such as a gas barrier layer or a printed layer, provided on the first base film 2.

[0075] Each layer in the packaging material of the present embodiment may contain the additives described above.

[0076] From the viewpoint of material recycling, the mass of the plastic material contained in the recycled material in the packaging material of this embodiment may be 10% by mass or more, 13% by mass or more, or 25% by mass or more based on the total mass of the plastic material in the packaging material. In other words, the packaging material of this embodiment may contain recycled material in a mass equivalent of plastic material of 10% by mass or more, 13% by mass or more, or 25% by mass or more based on the total amount of the plastic material in the packaging material. When the packaging material of this embodiment is a laminate packaging material, materials other than plastic (for example, adhesives, printing inks, aluminum foil, etc.) may be excluded from the mass calculation.

[0077] The plastic material contained in the recycled material (so-called recycled plastic) may be a resin contained in the recycled material contained in the layer containing the recycled material according to the present embodiment described above. The mass of post-industrial plastic among the recycled plastics may be calculated by multiplying the mass by 1 / 2.

[0078] The packaging material of this embodiment can be used for a standing pouch, a three-sided bag, a folded bag, a gusseted bag, a pouch with a spout, a pouch with a beak, and the like.

[0079] <Packaging bag> The packaging bag of this embodiment is made from the packaging material of this embodiment described above. The manufacturing style of the packaging bag is not particularly limited, but the packaging bag may be a standing pouch, a three-sided bag, a palm-shaped bag, a gusset bag, a pouch with a spout, a pouch with a beak, or the like.

[0080] Although the embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to the above-described embodiments. In addition, the above-described embodiments may be used in any combination. EXAMPLES

[0081] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[0082] <Preparing recycled materials> (Recycled materials 1) Recycled material 1 was obtained by compressing, cutting, and forming into granules an LLDPE film (manufactured by Mitsui Chemicals Tocello, product name "TUX FC-S", film thickness 100 μm) and a nylon film (manufactured by Kohjin Film & Chemicals Co., Ltd., product name "Bonny-Lu RX", film thickness 15 μm).

[0083] (Recycled materials 2) An LLDPE film (manufactured by Mitsui Chemicals Tohcello, product name "TUX FC-S", film thickness 100 μm) and a nylon film (manufactured by Kohjin Film & Chemicals, product name "Bonny-Lu RX", film thickness 15 μm) were each compressed, cut, and formed into granules. Recycled material 2 was obtained by dry blending the LLDPE granules and nylon granules so that the mass ratio of the nylon granules in the recycled material was 0.5 mass%.

[0084] (Recycled materials 3) An LLDPE film (manufactured by Mitsui Chemicals Tocello, product name "TUX FC-S", film thickness 100 μm) and a nylon film (manufactured by Kohjin Film & Chemicals, product name "Bonny-Lu RX", film thickness 15 μm) were each compressed, cut, and formed into granules. Recycled material 3 was obtained by dry blending the LLDPE granules and nylon granules so that the mass ratio of the nylon granules in the recycled material was 1 mass%.

[0085] (Recycled materials 4) Recycled material 4 was obtained by compressing, cutting, and forming an LLDPE film (manufactured by Mitsui Chemicals Tocello, product name "TUX FC-S", film thickness 100 μm) and a PET film (manufactured by Toyobo Co., Ltd., product name "E5102", film thickness 12 μm) into granules.

[0086] (Recycled materials 5) Recycled material 5 was obtained by compressing, cutting, and forming into granules an LLDPE film (manufactured by Tamapoly Co., Ltd., product name "UB-106T", film thickness 150 μm), a nylon film (manufactured by Kohjin Film & Chemicals Co., Ltd., product name "Bonny-Lu RX", film thickness 15 μm), and a PET film (manufactured by Toyobo Co., Ltd., product name "E5102", film thickness 12 μm).

[0087] (Recycled materials 6) A film in which an LLDPE film (manufactured by Tamapoly Co., Ltd., product name "UB-106T", film thickness 150 μm), an adhesive layer, an aluminum-deposited PET film (manufactured by Toray Film Processing Co., Ltd., product name "VM-PET 1310", film thickness 12 μm), an adhesive layer, a printed layer, and a nylon film (manufactured by Toyobo Co., Ltd., product name "Harden Film N1100", film thickness 15 μm) were laminated in this order was compressed, cut, and formed into granules to obtain recycled material 6. The adhesive layer was formed by dry lamination using an adhesive made by mixing Dick Dry LX-500 (manufactured by DIC Graphics, product name) as the main agent, KW75 (manufactured by DIC Graphics, product name) as the hardener, and NC401 (manufactured by Toyo Ink, product name) as the solvent.

[0088] (Recycled materials 7) A film in which an LLDPE film (manufactured by Mitsui Chemicals Tocello, product name "TUX FC-S", film thickness 80 μm), an adhesive layer, an aluminum-deposited PET film (manufactured by Toray Film Processing Co., Ltd., product name "VM-PET 1310", film thickness 12 μm), an adhesive layer, a printed layer, and a nylon film (manufactured by Toyobo Co., Ltd., product name "Harden Film N1100", film thickness 15 μm) were laminated in this order was compressed, cut, and formed into granules to obtain recycled material 7. The adhesive layer was formed by dry lamination using an adhesive made by mixing Dick Dry LX-500 (manufactured by DIC Graphics, product name) as the main agent, KW75 (manufactured by DIC Graphics, product name) as the hardener, and NC401 (manufactured by Toyo Ink, product name) as the solvent.

[0089] (Recycled materials 8) Recycled material 8 was obtained by compressing, cutting, and forming a granular shape from a PP film (manufactured by Toray Film Processing Co., Ltd., product name "Torayfan NO ZK207", film thickness 60 μm) and a nylon film (manufactured by Kohjin Film & Chemicals Co., Ltd., product name "Bonny-Lu RX", film thickness 15 μm).

[0090] (Recycled materials 9) A film consisting of an LLDPE film (Mitsui Chemicals Tocello, product name "TUX FC-S", film thickness 50 μm), an adhesive layer, an aluminum-deposited PET film (Toray Film Processing Co., Ltd., product name "VM-PET 1310", film thickness 12 μm), an adhesive layer, a printed layer, and a nylon film (Toyobo Co., Ltd., product name "Harden Film N1100", film thickness 15 μm) laminated in this order was compressed, cut, and formed into granules to obtain recycled material 9. The adhesive layer was formed by dry lamination using an adhesive mixture of Dikdry LX-500 (DIC Graphics, product name) as the base agent, KW75 (DIC Graphics, product name) as the hardener, and NC401 (Toyo Ink, product name) as the solvent.

[0091] <Preparation of Laminate> Example 1 Recycled material 1 was placed in the hopper extruding the intermediate layer, and LLDPE (manufactured by Prime Polymer, product name "Evolue SP2040") was placed in the hopper extruding the first and second layers, and laminate 1 having a laminated structure of first layer / intermediate layer / second layer was produced by co-extrusion molding using a single-screw multi-layer extruder. The thicknesses of the first and second layers were 5 μm, and the thickness of the intermediate layer was 30 μm.

[0092] Example 2 A laminate 2 was produced in the same manner as in Example 1, except that recycled material 2 was charged into the hopper for extruding the intermediate layer.

[0093] Example 3 A laminate 3 was produced in the same manner as in Example 1, except that recycled material 3 was charged into the hopper for extruding the intermediate layer.

[0094] Example 4 A laminate 4 was produced in the same manner as in Example 1, except that recycled material 4 was charged into the hopper for extruding the intermediate layer.

[0095] Example 5 A laminate 5 was produced in the same manner as in Example 1, except that recycled material 5 was charged into the hopper for extruding the intermediate layer.

[0096] Example 6 A laminate 6 was produced in the same manner as in Example 1, except that recycled material 6 was charged into the hopper for extruding the intermediate layer.

[0097] Example 7 A laminate 7 was produced in the same manner as in Example 1, except that recycled material 7 was charged into the hopper for extruding the intermediate layer.

[0098] Example 8 Laminate 8 was produced in the same manner as in Example 1, except that the thickness of the first layer and the second layer was 50 μm.

[0099] Example 9 A laminate 9 was produced in the same manner as in Example 1, except that the thickness of the first layer and the second layer was 100 μm.

[0100] Example 10 A laminate 10 was produced in the same manner as in Example 1, except that recycled material 8 was charged into the hopper extruding the intermediate layer, and a resin mixture obtained by mixing 70 parts by mass of propylene homopolymer and 30 parts by mass of propylene-ethylene random copolymer in pellet form was charged into the hopper extruding the first and second layers.

[0101] Comparative Example 1 A laminate C1 was produced in the same manner as in Example 1, except that recycled material 9 was charged into the hopper for extruding the intermediate layer.

[0102] <Evaluation of thickness range of laminate> For the laminate obtained above, the film thickness range was calculated by the following method. (Calculation of film thickness range) The film thickness of the laminate was measured in the width direction of the laminate (perpendicular to the flow direction during film production) using a continuous thickness measuring device (FT-A200) manufactured by Fujiwork Co., Ltd., at a measurement pitch of 0.1 mm and a measurement speed of 1.5 m / min. The maximum film thickness during measurement was designated Tmax (μm), and the minimum film thickness during measurement was designated Tmin (μm). The film thickness range (μm) of the laminate was calculated according to the following formula (1). Film thickness range = Tmax-Tmin … (1)

[0103] Films with a thickness range of 150 μm or less were marked "good", and films with a thickness range of over 150 μm were marked "bad".

[0104] <Evaluation of lamination suitability> A PET film (Mitsui Chemicals Tohcello, product name "E5202", film thickness 12μm) was dry laminated on the first layer side of the laminate using an adhesive made by mixing DIC Dry LX-500 (DIC Graphics, product name) as the base agent, KW75 (DIC Graphics, product name) as the hardener, and NC401 (Toyo Ink, product name) as the solvent. The obtained laminate was visually observed, and if there was no defective part (part that looks cloudy) where no adhesive was interposed between the substrate and the first layer of the laminate, it was marked as "◯", and if there was a defective part, it was marked as "X".

[0105] <Evaluation of the freedom to choose recycled materials> When the recycled material used in the intermediate layer contained two or more types of resin, it was marked as "good", and when it was a single resin, it was marked as "bad".

[0106] <Evaluation of peel strength> The laminate was cut to a width of 15 mm, and masking tape 21 was applied to the first layer 11 and the second layer 13 of the cut laminate 1 as shown in Fig. 3. The application and peeling of each masking tape 21 was alternately performed 20 times each. Thereafter, the coextrusion interface was visually confirmed, and a mark "◯" was given if no peeling occurred at the coextrusion interface, and a mark "X" was given if peeling occurred at the coextrusion interface.

[0107] <Impact resistance evaluation> The breaking strength of the laminate was measured using a film impact tester with a thermostatic chamber manufactured by Toyo Seiki Seisakusho Co., Ltd. under the conditions of temperature: 23°C, bullet size: 1 / 2 inch, and weight: 3.0 J. The breaking strength obtained was divided by the film thickness at the breaking point to calculate the value, and if this value was less than 9 J / mm it was marked as "x", if it was 9 J / mm or more but less than 12 J / mm it was marked as "△", if it was 12 J / mm or more but less than 17 J / mm it was marked as "◯", and if it was 17 J / mm or more it was marked as "◎".

[0108] [Table 1]

[0109] [Table 2]

[0110] As shown in Tables 1 and 2, the laminates of Examples 1 to 10, which have a thickness range of 150 μm or less, were confirmed to have sufficient lamination properties even though they contained recycled materials containing two or more types of resins. Furthermore, the laminates of Examples 1 to 10 were confirmed to have sufficient peel strength and impact resistance of 9 J / mm or more. [Explanation of symbols]

[0111] 1... laminate, 2... first base film, 3... printing layer, 4... second base film, 5... adhesive layer, 6... packaging material, 11... first layer, 12... intermediate layer, 13... second layer.

Claims

1. A laminate comprising a first layer, a second layer, and an intermediate layer provided between the first layer and the second layer, the first layer and the second layer contain virgin resin; The intermediate layer contains a recycled material containing two or more resins, The laminate has a thickness range of 150 μm or less.

2. The laminate according to claim 1 , wherein the content of the resin having the maximum mass ratio in the recycled material is 67 mass % or more based on the total mass of the recycled material.

3. The laminate according to claim 1 , wherein the first layer and the second layer each have a thickness of 5 μm or more and 100 μm or less.

4. The laminate according to claim 1 , wherein the resin having the largest mass ratio in the recycled material is a polyolefin resin.

5. 2. The laminate of claim 1, wherein the first layer and the second layer comprise the same type of virgin resin as the resin having the greatest mass fraction in the recycled material.

6. The laminate according to claim 1 , wherein the recycled material contains at least one of a polyamide resin and a polyester resin as a resin that does not have the largest mass ratio in the recycled material.

7. The laminate according to claim 1 , wherein the laminate has an impact resistance of 9 J / mm or more at 23° C.

8. A packaging material comprising the laminate according to any one of claims 1 to 7.

9. 9. The packaging material according to claim 8, wherein the recycled material is contained in an amount of 10% by mass or more, calculated as the mass of plastic material, based on the total amount of plastic material in the packaging material.

10. A packaging bag made from the packaging material according to claim 8.

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