Film and packaging material

Abstract

To provide a film and a packaging material in which deterioration in physical properties is suppressed even while containing a material recycled component.SOLUTION: A film includes a recycled-material-containing layer that contains a virgin resin and a material recycled component. The material recycled component contains 90 mass% or more of a resin of the same kind as the virgin resin, based on the total amount of the material recycled component. A content of the material recycled component is 50 mass% or less, based on the total mass of the film.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a film and a packaging material containing a material recycling material.

Background Art

[0002] Generally, 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 various applications. Examples of its uses include packaging materials for packaging food products, pharmaceuticals, etc., drip bags, shopping bags, posters, tapes, optical films used in liquid crystal TVs, etc., protective films, window films attached to windows, plastic greenhouses, building materials, and so on. Specific materials include, for example, thermoplastic resins such as polyethylene, polypropylene, polystyrene, acrylic polymethyl methacrylate, polycarbonate, polyamide, polyethylene terephthalate, polybutylene terephthalate, and thermosetting resins such as epoxy resins, polyurethanes, and polyimides.

[0003] An appropriate plastic material is selected according to the application, and furthermore, a plurality of them are stacked to form a laminate. In addition, there is also a way of using by mixing a plurality of plastic materials in one layer to compensate for the disadvantages of a single material. In addition, there are also laminates provided with an aluminum foil for imparting light-shielding properties, a printed layer printed with a pattern with ink to give the product a design, and an adhesive layer for adhering incompatible plastic materials.

[0004] In recent efforts to address environmental issues, the recycling of plastic products is expected, and various recycling methods are being studied. For example, for PET bottles, material recycling in which the collected products are washed and pulverized and reused as raw materials, and chemical recycling in which they are monomerized, have been established. Material recycling is considered desirable in terms of energy savings and cost reduction compared to chemical recycling.

[0005] By the way, packaging materials using plastic films were often discarded without being recycled after use. The reason is that packaging materials using plastic films usually have multiple materials laminated, and in material recycling, there were problems such as a decrease in processability or a deterioration in physical properties when processing them back into plastic films again.

[0006] Previously, technologies for material recycling of packaging materials have been studied. For example, Patent Document 1 below discloses that pellets were produced from pulverized food pouches and then formed into films using a T-die extruder.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] From the perspective of recyclability, it is desirable that the content of the material recyclable material contained in the film is large. On the other hand, films with a large content of the material recyclable material have deteriorated physical properties compared to virgin resin films.

[0009] In Patent Document 1 above, the formability of the film and the abundance of foreign substances in the pellets and the film are evaluated, but the physical properties of the film are not examined.

[0010] The present invention has been made in view of the above circumstances, and an object thereof is to provide a film and a packaging material that contain a material recyclable material and suppress a decrease in physical properties.

Means for Solving the Problems

[0011] One aspect of the present invention relates to the following [1] to [7]. [1] A film comprising a recycle material-containing layer containing virgin resin and a material recycle material, wherein the material recycle material contains 90% by mass or more of the same type of resin as the virgin resin, based on the total amount of the material recycle material, and the content of the material recycle material is 50% by mass or less based on the total mass of the film. [2] The film according to [1], wherein the material recycle material contains two or more types of resins. [3] The film according to [1] or [2], wherein the virgin resin is polyethylene or polypropylene. [4] The film according to any one of [1] to [3], further comprising a resin layer containing the same type of virgin resin as the virgin resin, laminated on one main surface of the recycle material-containing layer. [5] The film according to any one of [1] to [4], further comprising resin layers containing the same type of virgin resin as the virgin resin, laminated on both main surfaces of the recycle material-containing layer. [6] A packaging material comprising a base material layer and the film according to any one of [1] to [5], laminated on the base material layer. [7] The packaging material according to [6], wherein the content of the material recycle material is 10% by mass or more based on the total amount of the plastic material in the packaging material, in terms of the mass of the plastic material. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a film and a packaging material that contain a material recycle material and suppress a decrease in physical properties. [Brief Description of the Drawings]

[0013]

Figure 1

Figure 2

Figure 3

Mode for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present invention will be described in detail. Note that each figure is a schematically shown figure, and the size, shape, etc. of each part are exaggerated as appropriate for easy understanding. Also, for simplicity of explanation, the same reference numerals are given to corresponding parts in each figure. Further, the embodiments shown below are 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 following in terms of the material, shape, structure, etc. of the components. The technical idea of the present invention can be variously modified within the technical scope defined by the claims described in the claims.

[0015] [Film] The film of the present embodiment is a film including a recycled material-containing layer containing virgin resin and a material recycled material, wherein the material recycled material contains 90% by mass or more of the same resin as the virgin resin based on the total amount of the material recycled material, and the content of the material recycled material is 50% by mass or less based on the total mass of the film.

[0016] By having the above configuration, the film of the present embodiment can have sufficient physical properties (particularly tensile strength, breaking strength, and elongation at break) while containing a material recycled material. Further, since the film of the present embodiment has sufficient processability, film cracking and film breakage are less likely to occur during film formation, and it can be wound up well.

[0017] FIG. 1 is a cross-sectional view schematically showing an example of the film of the present embodiment. The film 1a shown in FIG. 1 includes a recycled material-containing layer 2 containing virgin resin and a material recycled material.

[0018] The content of the material recycling material in Film 1a may be 5% by mass or more, 10% by mass or more, 13% by mass or more, or 15% by mass or more based on the total mass of Film 1a from the viewpoint of the recyclability of the plastic film. The content of the material recycling material in Film 1a may be 50% by mass or less, 40% by mass or less, 30% by mass or less, or 20% by mass or less based on the total mass of Film 1a from the viewpoint of maintaining the processability of the film and suppressing the deterioration of the physical properties of the film. The content of the material recycling material may be 5 to 50% by mass, 15 to 50% by mass, or 15 to 20% by mass based on the total mass of Film 1a.

[0019] <Recycled material-containing layer> The recycled material-containing layer 2 of the present embodiment contains virgin resin and a material recycling material.

[0020] (Virgin resin) Examples of the virgin resin include thermoplastic resins such as polyolefin resins, polyester resins, polyamide resins, polystyrene resins, acrylic resins, and polycarbonate resins. The virgin resin can be used alone or in combination of two or more.

[0021] Examples of the polyolefin resin include polyethylene-based resins and polypropylene-based resins.

[0022] Examples of the polyethylene-based resin include low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), and ethylene-α-olefin copolymer.

[0023] Polyethylene 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 can be regarded as the same kind of resin. The polyethylene resin may contain a plurality of resins that are the same kind of resin but have different melting points, MFRs, etc.

[0024] The melting point of the polyethylene resin may be 100 - 140 °C, may be 105 - 135 °C, or may be 110 - 130 °C.

[0025] The MFR (melt flow rate) of the polyethylene resin may be 1 - 30, may be 2 - 20, or may be 3 - 15.

[0026] Examples of polypropylene resins include homopolypropylene (PP), block polypropylene, random polypropylene, and propylene-α-olefin copolymers.

[0027] Polypropylene resins such as homopolypropylene (PP), block polypropylene, random polypropylene, and propylene-α-olefin copolymers can be regarded as the same kind of resin. The polypropylene resin may contain a plurality of resins that are the same kind of resin but have different melting points, MFRs, etc.

[0028] The melting point of the polypropylene resin may be 120 - 170 °C, may be 130 - 165 °C, or may be 135 - 160 °C.

[0029] The MFR (melt flow rate) of the polypropylene resin may be 1 - 50, may be 2 - 30, or may be 3 - 20.

[0030] Examples of polyester resins include polyethylene terephthalate, polybutylene terephthalate, polylactic acid, etc.

[0031] Examples of the polyamide resin include nylon 6 and the like.

[0032] (Material recycling material) The material recycling material contains 90% by mass or more of a resin of the same type as the virgin resin contained in the recycling material-containing layer 2, based on the total amount of the material recycling material.

[0033] Examples of the material recycling material include post-consumer recycled (PCR) materials such as market-recovered bottles and packaging bags for beverages, detergents, and seasonings, food containers for bento and cup noodles, packaging bags for food and garbage bags, plastic finished products such as hangers, stationery, daily necessities, household appliances, and toys, and post-industrial recycled (PIR) materials such as defective products that do not become products discharged from factories, end materials generated during the process of making products, and plastic products used for transportation and packaging.

[0034] As the material recycling material, the above PIR material may be used. When using the PIR material as the material recycling material, compared with the PCR material, the adhesion of dust and dirt is less, and the quality of the material recycling material can be stabilized because the plastic material is also uniform for recovering specific plastic products.

[0035] When using the PCR material, since dirt may adhere to the surface during use, it may be washed in advance with a surfactant, an alkali, or the like.

[0036] The material recycling material may be a single material or may contain a plurality of materials. When the material recycling material contains a plurality of materials, those having a weight ratio of 90% by mass or more of the material with the largest proportion among the constituent materials (hereinafter also referred to as the "main constituent material") can be used. In this embodiment, when the material recycling material contains a plurality of materials, materials that are not of the same type as the main constituent material are referred to as sub-constituent materials.

[0037] Examples of the main constituent materials of the material recycling material include thermoplastic resins such as polyolefin resin, polyester resin, polyamide resin, polystyrene resin, acrylic resin, and polycarbonate resin.

[0038] Examples of the polyolefin resin include polyethylene-based resins and polypropylene-based resins. In this case, it becomes easy to impart heat sealability to the film.

[0039] Examples of the polyethylene-based resin include low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), and ethylene-α-olefin copolymer.

[0040] 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 copolymer can be regarded as the same kind of resin.

[0041] The polyethylene-based resin is the same kind of resin, but may contain a plurality of resins having different melting points, MFR, etc. The melting point and MFR of the polyethylene-based resin may be within the above-mentioned ranges.

[0042] Examples of the polypropylene-based resin include homopolypropylene (PP), block polypropylene, random polypropylene, and propylene-α-olefin copolymer.

[0043] Polypropylene-based resins such as homopolypropylene (PP), block polypropylene, random polypropylene, and propylene-α-olefin copolymer can be regarded as the same kind of resin.

[0044] The polypropylene-based resin is the same kind of resin, but may contain a plurality of resins having different melting points, MFR, etc. The melting point and MFR of the polypropylene-based resin may be within the above-mentioned ranges.

[0045] Examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, polylactic acid, and the like.

[0046] Examples of the polyamide resin include nylon 6 and the like.

[0047] Examples of the auxiliary constituent materials of the material recycling material containing a plurality of materials include ink, adhesive, thermoplastic resin other than the main constituent material, aluminum, alumina, silica, and the like. The auxiliary constituent material may contain two or more of these. Further, the auxiliary constituent material may be mixed and dispersed in the main constituent material, or may be contained in another layer laminated on the layer containing the main constituent material.

[0048] When using a material recycling material including a printing layer, it is preferable that the printing layer is surface-printed. By using such a material recycling material after physically or chemically removing the printing layer before pelletization, it is possible to suppress the appearance degradation due to coloring derived from the printing layer of the recycling material, and it becomes easy to obtain a highly transparent film.

[0049] The type of resin contained in the material recycling material can be confirmed by a microscopic infrared spectrophotometer or the like.

[0050] The content of the resin contained in the material recycling material can be measured by using a known method such as an extraction method.

[0051] In the recycling material-containing layer 2, the content of the material recycling material may be 20 to 90% by mass, 30 to 80% by mass, or 40 to 50% by mass based on the total mass of the recycling material-containing layer 2.

[0052] In the recycled material-containing layer 2, the content of the virgin resin may be 10 to 80% by mass, 20 to 70% by mass, or 50 to 60% by mass based on the total mass of the recycled material-containing layer 2. Further, the proportion of the same type of resin as the resin that is the main constituent material of the material recycled material in the virgin resin contained in the recycled material-containing layer 2 may be 90% by mass or more, 95% by mass or more, or 100% by mass.

[0053] The thickness of the recycled material-containing layer 2 may be 20 μm or more, 50 μm or more, or 100 μm or more. The thickness of the recycled material-containing layer 2 may be 200 μm or less, 150 μm or less, or 120 μm or less. The thickness of the recycled material-containing layer 2 may be 20 to 200 μm, 50 to 150 μm, or 100 to 120 μm.

[0054] In the recycled material-containing layer 2, additives such as 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 anti-fogging agent, a lubricant, a pigment, a dye, a dispersant, a copper damage inhibitor, a neutralizing agent, an anti-foaming agent, a weld strength improver, a natural oil, a synthetic oil, and a wax may be blended as necessary. The additives may be used singly or in combination of two or more.

[0055] The compatibilizer is appropriately selected according to the combination of the main constituent material and the sub-constituent material of the recycled material. Examples of the type of the compatibilizer include maleic anhydride-modified polyolefin, styrene-ethylene-butylene-styrene block copolymer (SEBS), ethylene-vinyl acetate copolymer (EVA), and the like.

[0056] Examples of the nucleating agent and reinforcing filler include talc, silica, clay, montmorillonite, calcium carbonate, lithium aluminum carbonate, alumina, titanium oxide, metals such as aluminum, iron, silver, and copper, hydroxides such as aluminum hydroxide and magnesium hydroxide, cellulose microfibril, celluloses such as cellulose acetate, fibrous fillers such as glass fiber, polyethylene terephthalate fiber, nylon fiber, polyethylene naphthalate fiber, aramid fiber, vinylon fiber, and polyacrylate fiber, carbons such as carbon nanotube, and elastomers such as ethylene propylene rubber (EPR).

[0057] Examples of the antioxidant include phenolic compounds, organic phosphite compounds, thioether compounds, and the like.

[0058] Examples of the heat stabilizer include hindered amine compounds and the like.

[0059] Examples of the ultraviolet absorber include benzophenone compounds, benzotriazole compounds, benzoate compounds, and the like.

[0060] Examples of the antistatic agent include nonionic compounds, cationic compounds, anionic compounds, and the like.

[0061] Examples of the flame retardant include halogen compounds, phosphorus compounds, nitrogen compounds, inorganic compounds, boron compounds, silicone compounds, sulfur compounds, red phosphorus compounds, and the like.

[0062] Examples of the flame retardant aid include antimony compounds, zinc compounds, bismuth compounds, magnesium hydroxide, clay silicate, and the like.

[0063] Examples of the anti-blocking agent include acrylic particles, styrene particles, styrene-acrylic particles and their crosslinked products, polyurethane particles, polyester particles, silicone particles, fluorine particles, copolymers thereof, zeolite, pyrophyllite, talc, smectite, vermiculite, mica, green mudstone, clay compound particles such as kaolin minerals and sepiolite, silica, titanium oxide, alumina, silica alumina, zirconia, zinc oxide, strontium oxide, aluminum hydroxide, strontium carbonate, strontium chloride, strontium sulfate, strontium nitrate, strontium hydroxide, glass particles and the like.

[0064] The film of the present embodiment may further include a resin layer containing virgin resin laminated on one main surface of the recycled material-containing layer. In this case, since the virgin resin layer can be made the outermost surface layer of the film, properties closely related to the surface state, that is, properties such as hygiene, printability, and heat sealability can be made equivalent to those of a virgin resin film.

[0065] The film of the present embodiment may further include resin layers containing virgin resin laminated on both main surfaces of the recycled material-containing layer. In this case, since the recycled material-containing layer is sandwiched by resin layers containing virgin resin, in addition to the fact that properties such as hygiene, printability, and heat sealability can be made equivalent to those of a virgin resin film, the above properties can be obtained without distinction between the front and back.

[0066] Figure 2 is a cross-sectional view schematically showing another example of the film of the present embodiment. The film 1b shown in Figure 2 includes a recycled material-containing layer 2 and two resin layers 3 laminated on both main surfaces of the recycled material-containing layer 2. The recycled material-containing layer 2 may be the same as that in the above-described film 1a.

[0067] The resin layer 3 may contain the same type of virgin resin as the virgin resin contained in the recycled material-containing layer 2 (i.e., the resin that is the main constituent material of the material recycled material) (hereinafter also referred to as a predetermined virgin resin). In this case, the films 1a and 1b can have characteristics (e.g., processability, physical properties, etc.) close to those of the film of the predetermined virgin resin. For example, by using the same type of virgin resin, advantages such as easily obtaining an integrated film by coextrusion processing in processing can be enjoyed.

[0068] Also, when the predetermined virgin resin is a polyethylene-based resin or a polypropylene-based resin, it becomes easy to impart heat sealability to the film.

[0069] From the viewpoint of the recyclability of the plastic film, the content of the material recycled material in the film 1b may be 5% by mass or more, 10% by mass or more, 13% by mass or more, or 15% by mass or more based on the total mass of the film 1b. From the viewpoint of maintaining the processability of the film and suppressing the deterioration of the physical properties of the film, the content of the material recycled material in the film 1b may be 50% by mass or less, 40% by mass or less, 30% by mass or less, or 20% by mass or less based on the total mass of the film 1b. The content of the material recycled material may be 5 to 50% by mass, 15 to 50% by mass, or 15 to 20% by mass based on the total mass of the film 1a.

[0070] The thickness per layer of the resin layer 3 may be 1 μm or more, 5 μm or more, 10 μm or more, 20 μm or more, or 50 μm or more, or may be 20 μm or less, 10 μm or less, or 5 μm or less.

[0071] The thickness of the recycled material-containing layer 2 in the film 1b may be 20% or more, 25% or more, or 35% or more based on the thickness of the film 1b. The thickness of the recycled material-containing layer 2 may be 75% or less, or 60% or less based on the thickness of the film 1b.

[0072] The thickness of the recycled material-containing layer 2 in the film 1b may be 100 μm or less, 80 μm or less, or 60 μm or less.

[0073] The total thickness of the film of this embodiment can be appropriately selected according to the intended use. For example, when used as a sealant for packaging materials, it may be 10 μm or more and 200 μm or less.

[0074] [Method for manufacturing the film] The film of this embodiment can be manufactured using a known method. For example, a method of finely cutting a material recycled material in advance, pelletizing it, blending it with virgin resin, melting it using an extrusion molding machine, and forming a film with a T-die through a feed block or a multi-manifold, or forming a film by an inflation method can be mentioned.

[0075] Also, when forming a multi-layer structure as shown in FIG. 2, it can be manufactured by a co-extrusion method. That is, using a plurality of extrusion molding machines, melting the resin compositions for forming the recycled material-containing layer and the resin layer with each extruder, merging them with a feed block or a multi-manifold, and forming a film with a T-die, or forming a film by an inflation method to manufacture a multi-layer film.

[0076] As a method of mixing the material recycled material and the virgin resin, it may be a dry blend in which the virgin resin and the material recycled material are simultaneously charged into a hopper and film is formed while melt-kneading, or a melt blend in which the virgin material and the material recycled material are separately melt-kneaded with a twin-screw extruder to form a masterbatch.

[0077] In order to enhance the dispersibility of the main constituent material and the auxiliary constituent material contained in the material recycling material, and the virgin resin of the same type as the main constituent material, repelletizing using a twin-screw extruder, molding under high shear conditions, and blending an acid-modified polyolefin resin or the like as a compatibilizer, one or more of these means may be used.

[0078] The film of this embodiment can be used as a sealant film for a packaging material, a base film for a packaging material, or a label base material.

[0079] [Packaging material] The packaging material of this embodiment includes a base material layer and the film of this embodiment laminated on the base material layer.

[0080] FIG. 3 is a cross-sectional view schematically showing an example of the packaging material of this embodiment. The packaging material 10 shown in FIG. 3 includes a functional layer 5 laminated via an adhesive layer 4 on the resin layer 3 of the film 1b, and a base material layer 7 having a printing layer 6 laminated via an adhesive layer 4 on the functional layer 5.

[0081] The adhesive constituting the adhesive layer 4 is not particularly limited, and for example, a dry lamination adhesive can be used. Examples of the dry lamination adhesive include two-component curable urethane adhesives, polyester urethane adhesives, polyether urethane adhesives, acrylic adhesives, polyester adhesives, polyamide adhesives, epoxy adhesives, and the like.

[0082] The functional layer 5 is a layer appropriately provided according to the characteristics required for the use of the packaging material 10, and can be provided, for example, to reinforce the mechanical strength of the packaging material or to impart gas barrier properties or the like.

[0083] Examples of the material constituting the functional layer 5 for imparting gas barrier properties include gas barrier films, metal foils such as aluminum foil, and vapor deposition films having a vapor deposition layer on a plastic film. Examples of the material constituting the vapor deposition layer include alumina, silica, and aluminum. Examples of the gas barrier film include films of ethylene-vinyl alcohol copolymer, polyamide-based resin, polyvinylidene chloride-based resin, polyacrylonitrile-based resin, etc.

[0084] Examples of the material constituting the functional layer 5 for reinforcing mechanical strength include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate, polyolefins such as polyethylene and polypropylene, polyamides such as polystyrene and 6-nylon, polycarbonate, polyacrylonitrile, polyimide, etc.

[0085] When there are a plurality of properties required for the packaging material 10, a plurality of functional layers 5 may be provided. For example, two or more functional layers may be laminated via an adhesive layer.

[0086] The base material layer 7 is not particularly limited as long as it has mechanical strength and dimensional stability, but plastic films, paper, non-woven fabrics, etc. can be used. Examples of the constituent material of the plastic film include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate, polyolefins such as polyethylene and polypropylene, polyamides such as polystyrene and 6-nylon, polycarbonate, polyacrylonitrile, polyimide, etc.

[0087] A printing layer 6 may be laminated on the base material layer 7. At this time, the printing layer may be a front printing or a back printing. Note that by making it a front printing, it becomes easier to remove the printing layer when the packaging material 10 is recycled again. From the viewpoint of recyclability, the printing layer may be a front printing.

[0088] Each layer in the packaging material 10 may contain the above-described additives.

[0089] From the perspective of material recycling, the content of the material recycling material contained in the packaging material of this embodiment may be 10% by mass or more, or 25% by mass or more, based on the total amount of the plastic material in the packaging material in terms of the mass of the plastic material. When the packaging material of this embodiment is a laminated packaging material, materials other than the plastic material (for example, adhesives, printing inks, aluminum foils, etc.) may be excluded from the weight calculation.

[0090] In the packaging material of this embodiment, for example, by means such as reducing the thickness of the functional layer and the base material layer, or making the resin contained in each layer constituting the packaging material the same type of resin as the main constituent material of the material recycling material, the total content of the resin of the same type as the main constituent material of the material recycling material in the film of this embodiment may be adjusted so that it is 90% by mass or more based on the total mass of the packaging material. In this case, the packaging material has enhanced recyclability because 90% by mass is composed of the same type of resin, and it can be reused as the material recycling material for the film of this embodiment.

[0091] The packaging material of this embodiment can be used for standing pouches, three-side bags, clasp bags, gusset bags, pouches with spouts, pouches with beaks, etc.

Examples

[0092] Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

[0093] [Production of Recycling Material] (Recycling Material 1) A linear low-density polyethylene (LLDPE) film (manufactured by Prime Polymer Co., Ltd., product name "SP3530", melting point 123 °C, film thickness 100 μm), a nylon (Ny) film (manufactured by Unitika Ltd., product name "A1025SR", film thickness 10 μm), and a high-density polyethylene (HDPE) film (manufactured by Japan Polyethylene Corporation, product name "HY350", melting point 132 °C, film thickness 12 μm) were each prepared. These films were dry laminated using an adhesive (Dick Dry LX-500 (manufactured by DIC Graphics Co., Ltd.) as the main agent and KW75 (manufactured by DIC Graphics) as the curing agent) to produce a film in which the LLDPE film, Ny film, and HDPE film were laminated in this order. After compressing and cutting this film into a fluff shape, it was pelletized by heat melting to obtain a pelletized recycled material 1. The pelletization was carried out under the conditions of a temperature of 230 °C and a shear rate of 1530 sec -1 .

[0094] The main constituent material of the recycled material 1 is polyethylene (PE), and the ratio of the main constituent material in the recycled material 1 is 90% by mass based on the total amount of the recycled material 1.

[0095] (Recycled material 2) A polypropylene (PP) film (manufactured by Japan Polypropylene Corporation, product name "BC6DRF", melting point 163 °C, film thickness 100 μm), a Ny film (manufactured by Unitika Ltd., product name "A1025SR", film thickness 10 μm), and a polypropylene (PP) film (manufactured by Japan Polypropylene Corporation, product name "BC6DRF", film thickness 12 μm) were each prepared. These films were dry laminated in the same manner as the recycled material 1 to produce a film in which the PP film, Ny film, and PP film were laminated in this order. After compressing and cutting this film into a fluff shape, it was pelletized by heat melting to obtain a pelletized recycled material 2. The pelletization was carried out under the conditions of a temperature of 230 °C and a shear rate of 1530 sec -1 .

[0096] The main constituent material of the recycled material 2 is polypropylene (PP), and the ratio of the main constituent material in the recycled material 2 was 90% by mass based on the total amount of the recycled material 2.

[0097] (Recycled material 3) An LLDPE film (manufactured by Prime Polymer Co., Ltd., product name "SP3530", film thickness 100 μm), a Ny film (manufactured by Unitika Ltd., product name "A1025SR", film thickness 24 μm), and an HDPE film (manufactured by Japan Polyethylene Corporation, product name "HY350", film thickness 12 μm) were each prepared. These films were dry laminated in the same manner as the recycled material 1 to produce a film in which the LLDPE film, Ny film, and HDPE film were laminated in this order. After this film was compressed, cut into a fluff shape, and pelletized by heat melting, pellet-shaped recycled material 3 was obtained. The pelletization was carried out under the conditions of a temperature of 230°C and a shear rate of 1530 sec -1 of.

[0098] The main constituent material of the recycled material 3 is polyethylene (PE), and the ratio of the main constituent material in the recycled material 3 was 80% by mass based on the total amount of the recycled material 3.

[0099] [Production of film] (Example 1) The pellets of the recycled material 1 as the material recycled material and the pellets of LLDPE (manufactured by Prime Polymer Co., Ltd., product name "SP3530") as the virgin resin were dry blended so that the mass ratio of the material recycled material to the virgin resin was 50:50, and this was formed into a film with a film thickness of 100 μm by an extruder.

[0100] (Example 2) As the material recycling material, pellets of recycling material 2 and, as virgin resin, PP (manufactured by Nippon Polypro Co., Ltd., product name "BC6DRF") pellets were dry-blended so that the mass ratio of the material recycling material to the virgin resin was 50:50, and this was formed into a film by an extruder to produce a film with a thickness of 100 μm.

[0101] (Example 3) As the material recycling material, pellets of recycling material 1 and, as virgin resin, LLDPE (manufactured by Prime Polymer Co., Ltd., product name "SP3530") pellets were dry-blended so that the mass ratio of the material recycling material to the virgin resin was 70:30 to obtain a mixed resin for forming a recycling material-containing layer. Using this mixed resin and LLDPE (manufactured by Prime Polymer Co., Ltd., product name "SP3530") for forming a resin layer, a film having a three-layer structure of resin layer / recycling material-containing layer / resin layer was produced by co-extrusion film formation using a multi-layer extruder. At this time, co-extrusion film formation was performed so that the thickness of the recycling material-containing layer, which is the inner layer, was 70 μm and the thickness of each of the resin layers, which are the two outer layers, was 15 μm.

[0102] (Example 4) As the material recycling material, pellets of recycling material 2 and, as virgin resin, PP (manufactured by Nippon Polypro Co., Ltd., product name "BC6DRF") pellets were dry-blended so that the mass ratio of the material recycling material to the virgin resin was 70:30 to obtain a mixed resin for forming a recycling material-containing layer. Using this mixed resin and PP (manufactured by Prime Polymer Co., Ltd., product name "SP3530") for forming a resin layer, a film having a three-layer structure of resin layer / recycling material-containing layer / resin layer was produced by co-extrusion film formation using a multi-layer extruder. At this time, co-extrusion film formation was performed so that the thickness of the recycling material-containing layer, which is the inner layer, was 70 μm and the thickness of each of the resin layers, which are the two outer layers, was 15 μm.

[0103] (Example 5) The pellets of recycled material 1 as the material recycling material and the pellets of LLDPE (manufactured by Prime Polymer Co., Ltd., product name "SP3530") as virgin resin were dry-blended so that the mass ratio of the material recycling material to the virgin resin was 20:80, and this was formed into a film by an extruder to produce a film with a thickness of 100 μm.

[0104] (Example 6) The pellets of recycled material 1 as the material recycling material and the pellets of LLDPE (manufactured by Prime Polymer Co., Ltd., product name "SP3530") as virgin resin were dry-blended so that the mass ratio of the material recycling material to the virgin resin was 90:10 to obtain a mixed resin for forming a recycled material-containing layer. Using this mixed resin and LLDPE (manufactured by Prime Polymer Co., Ltd., product name "SP3530") for forming a resin layer, a film having a three-layer structure of resin layer / recycled material-containing layer / resin layer was produced by coextrusion film formation using a multi-layer extruder. At this time, coextrusion film formation was performed so that the thickness of the recycled material-containing layer, which is the inner layer, was 20 μm and the thickness of each of the resin layers, which are the outer layers, was 40 μm.

[0105] (Comparative Example 1) A film with a thickness of 100 μm was produced in the same manner as in Example 1 except that the pellets of recycled material 3 were used instead of the pellets of recycled material 1.

[0106] (Comparative Example 2) The pellets of recycled material 1 and the pellets of LLDPE (manufactured by Prime Polymer Co., Ltd., product name "SP3530") as virgin resin were dry-blended so that the mass ratio of the material recycling material to the virgin resin was 60:40, and this was formed into a film by an extruder to produce a film with a thickness of 100 μm.

[0107] (Comparative Example 3) The pellets of recycled material 1 as the material recycling material and the pellets of LLDPE (manufactured by Prime Polymer Co., Ltd., product name "SP3530") as the virgin resin were dry blended so that the mass ratio of the material recycling material to the virgin resin was 70:30 to obtain a mixed resin for forming a recycled material-containing layer. Using this mixed resin and LLDPE (manufactured by Prime Polymer Co., Ltd., product name "SP3530") for forming a resin layer, a film having a three-layer structure of resin layer / recycled material-containing layer / resin layer was produced by coextrusion film formation using a multi-layer extruder. At this time, coextrusion film formation was performed so that the film thickness of the recycled material-containing layer as the inner layer was 80 μm and the film thicknesses of both outer resin layers were each 10 μm.

[0108] (Comparative Example 4) The pellets of recycled material 3 as the material recycling material and the pellets of LLDPE (manufactured by Prime Polymer Co., Ltd., product name "SP3530") as the virgin resin were dry blended so that the mass ratio of the material recycling material to the virgin resin was 50:50 to obtain a mixed resin for forming a recycled material-containing layer. Using this mixed resin and LLDPE (manufactured by Prime Polymer Co., Ltd., product name "SP3530") for forming a resin layer, a film having a three-layer structure of resin layer / recycled material-containing layer / resin layer was produced by coextrusion film formation using a multi-layer extruder. At this time, coextrusion film formation was performed so that the film thickness of the recycled material-containing layer as the inner layer was 70 μm and the film thicknesses of both outer resin layers were each 15 μm.

[0109] (Reference Example 1) LLDPE (manufactured by Prime Polymer Co., Ltd., product name "SP3530") as the virgin resin was formed into a film with a film thickness of 100 μm by an extruder.

[0110] (Reference Example 2) PP (manufactured by Nippon Polypro Co., Ltd., product name "BC6DRF") as the virgin resin was formed into a film with a film thickness of 100 μm by an extruder.

[0111] [Evaluation of Film Properties] For the films of Examples 1 to 6 and Comparative Examples 1 to 4, the processability, tensile strength, breaking strength, elongation at break, and heat sealability were evaluated by the following methods, respectively.

[0112] [Evaluation of Processability] From film formation to winding of the film, the appearance was visually observed, and the film formation processability was evaluated according to the following criteria. "〇": No film cracking or film breakage occurs, and it can be wound in the form of a film. "×": Holes are formed in the film due to film cracking, and cracks enter both ends of the film due to film breakage.

[0113] [Tensile Test] For the prepared films, a tensile test was performed by a method conforming to "JIS K7161 Plastics - Method for Determination of Tensile Properties". The tensile test was carried out using a tensile testing machine (manufactured by Shimadzu Corporation, model number AGS - 500NX), with the film cut to a width of 15 mm and tested under the conditions of a chuck - to - chuck distance of 50 mm and a tensile speed of 100 mm / min. The tensile strength, breaking strength, and elongation at break of each film were obtained by this tensile test.

[0114] [Evaluation of Tensile Strength] Taking the film of Reference Example 1 as the reference for the film whose main constituent material is PE, and the film of Reference Example 2 as the reference for the film whose main constituent material is PP, the tensile strengths of the films of Examples 1 to 6 and Comparative Examples 1 to 4 were evaluated according to the following evaluation criteria. The evaluation of the tensile strengths of the films of Reference Examples 1 and 2 was set as "◎". "◎": The numerical value of the tensile strength is 90% or more with respect to the tensile strength of the reference film. "○": The numerical value of the tensile strength is 75% or more and less than 90% with respect to the tensile strength of the reference film. "△": The numerical value of the tensile strength is 60% or more and less than 75% with respect to the tensile strength of the reference film. "×": The numerical value of the tensile strength is less than 60% with respect to the tensile strength of the reference film.

[0115] [Evaluation of Tensile Strength] For the films whose main constituent material is PE, based on the film of Reference Example 1, and for the films whose main constituent material is PP, based on the film of Reference Example 2, the tensile strengths of the films of Examples 1 to 6 and Comparative Examples 1 to 4 were evaluated according to the following evaluation criteria. Note that the evaluation of the tensile strength of the films of Reference Examples 1 and 2 was rated as "◎". "◎": The numerical value of the tensile strength is 90% or more with respect to the tensile strength of the reference film. "○": The numerical value of the tensile strength is 75% or more and less than 90% with respect to the tensile strength of the reference film. "△": The numerical value of the tensile strength is 60% or more and less than 75% with respect to the tensile strength of the reference film. "×": The numerical value of the tensile strength is less than 60% with respect to the tensile strength of the reference film.

[0116] [Evaluation of Elongation at Break] For the films whose main constituent material is PE, based on the film of Reference Example 1, and for the films whose main constituent material is PP, based on the film of Reference Example 2, the elongations at break of the films of Examples 1 to 6 and Comparative Examples 1 to 4 were evaluated according to the following evaluation criteria. Note that the evaluation of the tensile strength of the films of Reference Examples 1 and 2 was rated as "◎". "◎": The numerical value of the elongation at break is 90% or more with respect to the elongation at break of the reference film. "○": The numerical value of the elongation at break is 75% or more and less than 90% with respect to the elongation at break of the reference film. "△": The numerical value of the elongation at break is 60% or more and less than 75% with respect to the elongation at break of the reference film. "×": The numerical value of the elongation at break is less than 60% with respect to the elongation at break of the reference film.

[0117] [Evaluation of Heat Sealability (HS Property)] Using a heat sealer (model number TP-701-B) manufactured by Tester Sangyo Co., Ltd., films were sealed under the conditions of seal pressure: 0.2 MPa, seal time: 1 second, and seal width: 10 mm. The seal temperature was 130 °C for films whose main constituent material was PE and 170 °C for films whose main constituent material was PP. The sealed films were cut into pieces measuring 15 mm in width and 100 mm in length, and a tensile test was conducted using a tensile testing machine (manufactured by Shimadzu Corporation, model number AGS-500NX) under the conditions of a distance between chucks of 50 mm and a tensile speed of 300 mm / min. The maximum tensile strength was taken as the seal strength of the film.

[0118] For films whose main constituent material was PE, based on the film of Reference Example 1, and for films whose main constituent material was PP, based on the film of Reference Example 2, the heat sealability of the films of Examples 1 to 6 and Comparative Examples 1 to 4 was evaluated according to the following evaluation criteria. Note that the evaluation of the tensile strength of the films of Reference Examples 1 and 2 was rated as "◎". "◎": The numerical value of the seal strength is 90% or more with respect to the seal strength of the reference film. "○": The numerical value of the seal strength is 75% or more and less than 90% with respect to the seal strength of the reference film. "×": The numerical value of the seal strength is less than 75% with respect to the seal strength of the reference film.

[0119] The evaluation results of Examples 1 to 6, Comparative Examples 1 to 4, and Reference Examples 1 to 2 are shown in Tables 1 and 2 below, respectively. Note that the notations of the main constituent material and virgin resin in Tables 1 and 2 are as follows. PP: Polypropylene (manufactured by Polypro Co., Ltd., product name "BC6DRF", melting point 163 °C) PE: Linear low-density polyethylene (LLDPE) (manufactured by Prime Polymer Co., Ltd., product name "SP3530", melting point 123 °C)

[0120]

Table 1

[0121]

Table 2

[0122] (Evaluation results) As shown in Table 1, it was confirmed that the films of Examples 1 to 6, while containing a recycled material, sufficiently suppressed the deterioration of physical properties compared to virgin resin films. Further, it was confirmed that the films of Examples 1 to 6 had good processability and sufficiently exhibited heat seal strength. Therefore, the film of the present invention can be applied as a sealant film for packaging materials.

[0123] It was confirmed that the films of Examples 3 to 4, which further include a resin layer containing virgin resin, had heat sealability close to that of virgin resin films.

[0124] It was confirmed that the films of Examples 5 to 6, in which the content of the material recycled material in the film was 18% by mass, had physical properties (tensile strength, breaking strength, elongation at break) and heat sealability close to those of virgin resin films.

Explanation of symbols

[0125] 1a, 1b... films, 2... recycled material-containing layer, 3... resin layer, 4... adhesive layer, 5... functional layer, 6... printing layer, 7... base material layer, 10... packaging material.

Claims

1. A film comprising a recycle material-containing layer containing virgin resin and a material recycle material, wherein the material recycle material contains 90% by mass or more of the same type of resin as the virgin resin, based on the total amount of the material recycle material, the content of the material recycle material is 50% by mass or less based on the total mass of the film.

2. The film according to Claim 1, wherein the material recycle material contains two or more types of resins.

3. The film according to Claim 1, wherein the virgin resin is polyethylene or polypropylene.

4. The film according to Claim 1, further comprising a resin layer containing the same type of virgin resin as the virgin resin, laminated on one main surface of the recycle material-containing layer.

5. The film according to Claim 1, further comprising a resin layer containing the same type of virgin resin as the virgin resin, laminated on both main surfaces of the recycle material-containing layer.

6. A packaging material comprising a base material layer and the film according to any one of Claims 1 to 5 laminated on the base material layer.

7. The packaging material according to Claim 6, wherein the content of the material recycle material is 10% by mass or more based on the total amount of the plastic material in the packaging material, in terms of the mass conversion of the plastic material.

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