Laminated film for packaging material, and packaging bag

Abstract

To provide a packaging bag which is made of an environmentally friendly laminated film for a packaging material and has processing suitability, physical properties, and especially durability which are comparable to those of a packaging bag made of a petroleum resin.SOLUTION: A laminated film 12 for a packaging material comprises: a sealant film 13 made of a resin composition containing a plant-derived low-density polyethylene resin obtained by polymerizing plant-derived ethylene by a high-pressure method; and a base material film 14 having a printed pattern. The base material film is a polyester resin film. The base material film having the printed pattern and the sealant film are laminated by an adhesive for lamination. The laminated film for the packaging material has a biomass degree of at least 25% as calculated from a measurement value of radioactive carbon dating. The sealant film does not contain 0.2 mass% or more of silica, and 5.0 mass% or more of titanium oxide, an ionomer and an ethylene-methacrylic acid copolymer.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a laminate film for packaging materials and a packaging bag, and more specifically, to a laminate film for packaging materials laminated with a film made of a resin composition containing a plant-derived low-density polyethylene resin, and a packaging bag using the film. [Background technology]

[0002] For example, flexible packaging (light packaging) that is widely used as a packaging form for frozen foods such as dumplings, pan-fried shumai, fried rice, and pizza is composed of a flexible packaging material consisting of a sealant film and a base film. However, many of the raw materials for flexible packaging materials are derived from petroleum, and there is a need to address environmental issues and the conservation of exhaustible resources such as petroleum. A packaging bag (e.g., Patent Document 1) is known that contains a biodegradable resin composition in which a polylactic acid resin, which is a carbon-neutral material, contains a predetermined amount of an ethylene-α-olefin copolymer and a polymer having an epoxy group, with the aim of reducing the amount of petroleum resources used in packaging materials. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-155516 A Summary of the Invention [Problem to be solved by the invention]

[0004] The ratio of petroleum-derived raw materials can be reduced by adding a biodegradable resin other than petroleum-derived raw materials to the resin composition constituting the packaging bag. However, such packaging bags are significantly inferior in processability such as tensile strength, tear strength, seal strength, and stiffness compared to those made of petroleum-based resins, making it difficult to improve the productivity and durability.

[0005] Therefore, an object of the present invention is to provide an environmentally friendly laminated film for packaging materials that conserves petroleum resources and reduces carbon dioxide emissions, and a packaging bag made from this film that has processability and physical properties, particularly durability, that are comparable to those of packaging bags made from petroleum-based resins. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention provides a laminate film for packaging materials, comprising a sealant film made of a resin composition containing a plant-derived low-density polyethylene resin obtained by polymerizing plant-derived ethylene using a high-pressure method, and a base film having a printed pattern, the base film being a polyester-based resin film, the base film having the printed pattern and the sealant film being laminated together via a laminating adhesive, the laminate film for packaging materials having a biomass degree of at least 25% calculated from a measurement value of 14C radiocarbon dating, and the sealant film not containing 0.2% by mass or more of silica, 5.0% by mass or more of titanium oxide, ionomer, or ethylene-methacrylic acid copolymer. Furthermore, the plant-derived low-density polyethylene resin is characterized by having a biomass ratio of 10 to 100%. Furthermore, the base film is characterized in that it is a film made of a resin composition containing a plant-derived polyethylene terephthalate resin obtained by condensation polymerization of plant-derived ethylene glycol and petroleum-derived terephthalic acid. Furthermore, the sealant film contains 10 to 15% by weight of the plant-derived low-density polyethylene resin. The present invention is characterized in that the resin composition contains 100% by weight of polyethylene terephthalate derived from petroleum and 0 to 90% by weight of a petroleum-derived low-density polyethylene resin, and is composed of either (A) or (B) below. (A) A single layer structure made of the resin composition (B) A multi-layer structure in which the middle layer is made of the resin composition, and the outer and inner layers are made of the petroleum-derived low-density polyethylene resin. Furthermore, the packaging bag of the present invention is characterized in that it is made using the above-mentioned laminated film for packaging materials. Effect of the Invention

[0007] According to the present invention, a laminated film for packaging material is provided by laminating a base film and a sealant film made of a resin composition containing a plant-derived low-density polyethylene resin obtained by polymerizing plant-derived ethylene by a high-pressure method, and the laminated film for packaging material is capable of being subjected to radiocarbon dating. 14 Since the biomass degree calculated from the measured value of C is at least 25%, it is possible to reduce the amount of petroleum resources used as a raw material for the sealant film constituting the laminated film for packaging materials, and to suppress the amount of petroleum-derived carbon dioxide emissions during the production and disposal of the film. Furthermore, since the physical properties are comparable to those of petroleum-derived low-density polyethylene resins, the manufacturing process can be the same as that of existing laminated films for packaging materials, and raw materials can be changed without impairing the processing suitability of the packaging material. Furthermore, the origin of the raw materials of the low-density polyethylene resin constituting the laminated film for packaging materials can be identified using this biomass degree as an index, and the origin of the raw materials can be confirmed from the time of production to the time of disposal of the film. Therefore, it is possible to provide a laminated film for packaging materials containing a low-density polyethylene resin that has a reduced environmental load, is excellent in production efficiency, and allows the origin of the raw materials to be identified.

[0008] Furthermore, when the plant-derived low-density polyethylene resin has a biomass ratio of 10 to 100%, the petroleum-derived content of the low-density polyethylene resin constituting the sealant film can be further reduced, thereby further reducing the amount of petroleum resources used and further suppressing petroleum-derived carbon dioxide emissions during film production and disposal.

[0009] Furthermore, when the base film is a film made of a resin composition containing a plant-derived polyethylene terephthalate resin obtained by condensation polymerization of plant-derived ethylene glycol and petroleum-derived terephthalic acid, the ratio of petroleum-derived raw materials used in the base film can be reduced, further reducing the amount of petroleum resources used and further suppressing petroleum-derived carbon dioxide emissions during the production and disposal of the laminated film for packaging materials. The laminated film for packaging materials has tensile strength, seal strength, and stiffness suitable for use in packaging bags, for example, soft packaging bags, and shows excellent processability.

[0010] Furthermore, the sealant film is produced by using a resin composition containing 10 to 100 mol % of a plant-derived low-density polyethylene resin and 0 to 90 mol % of a petroleum-derived low-density polyethylene resin, and is formed by the following processes (A) and (B): (A) Single layer structure made by mixing a resin composition and a petroleum-derived low-density polyethylene resin (B) A multi-layer structure in which the middle layer is a layer made of a mixture of a resin composition and a petroleum-derived low-density polyethylene resin, and the outer layer and inner layer are made of petroleum-derived low-density polyethylene resin. According to any one of the above configurations, the ratio of petroleum-derived low-density polyethylene resin used in the laminate film for packaging can be reduced, reducing the amount of petroleum resources used and suppressing petroleum-derived carbon dioxide emissions during film production and disposal. In addition, by using petroleum-derived low-density polyethylene resin in the inner and outer layers constituting the sealant film such as (B), the film can be produced with the properties of existing production processes. Therefore, a laminate film for packaging with better processability can be provided.

[0011] Furthermore, by providing an intermediate layer between the sealant film and the base film, the laminate film for packaging material can be configured to have various functions, for example, gas barrier properties.

[0012] Furthermore, since the packaging bag of the present invention is made using the above-mentioned laminated film for packaging material, the ratio of petroleum-derived low-density polyethylene resin used in the laminated film for packaging material constituting the packaging bag can be reduced, the amount of petroleum resources used can be reduced, and petroleum-derived carbon dioxide emissions during the manufacture and disposal of the packaging bag can be suppressed. Furthermore, the ratio of petroleum-derived raw materials used in the packaging bags that are widely distributed in the world as disposable can be reduced. Furthermore, as described above, the processing suitability and physical properties of the laminated film for packaging material are comparable to those of petroleum-derived materials. Therefore, it is possible to provide a packaging bag that contains a plant-derived low-density polyethylene resin that saves petroleum resources and reduces the environmental load, and has processing suitability and physical properties, especially durability, that are comparable to those of petroleum-based resins. [Brief description of the drawings]

[0013] [Figure 1] 1 is a flow chart illustrating the manufacturing process of sugarcane-derived low density polyethylene film. [Diagram 2] FIG. 1 is a cross-sectional view showing a sealant film containing a sugar cane-derived low-density polyethylene resin according to an embodiment of the present invention. [Diagram 3] FIG. 2 is a cross-sectional view showing a schematic diagram of a film having a multilayer structure in which a middle layer is made of bio-based low-density polyethylene resin. [Figure 4] 1 is a cross-sectional view showing a schematic example of a laminate film for packaging material according to the present embodiment. FIG. [Diagram 5] 1 is a flow chart illustrating a process for producing a plant-derived polyethylene terephthalate film. [Figure 6] FIG. 1 is a cross-sectional view showing a schematic example of a packaging bag produced by heat-sealing a laminated film for packaging materials. [Figure 7] 1 is a perspective view showing a four-side sealed bag as an example of a packaging bag formed using the packaging laminate film according to the present embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0015] Flexible packaging, which is widely used for food and daily necessities, is made of laminated film. Some laminated films are made by laminating a sealant film (heat-sealable film) that serves as a heat-sealing material for the inner surface of the flexible packaging onto a base film. For example, polyester resins are used as materials for the base film. Meanwhile, low-density polyethylene (LDPE: Low Density PolyEthylene (PE-LD)) resins are used as materials for the sealant film. Low-density polyethylene resins are inexpensive and have excellent flexibility, transparency, extrusion coating properties, thermal adhesion, etc.

[0016] Thus, low-density polyethylene resins and polyester-based resins are often used as materials for laminated films. These low-density polyethylene resins and polyester-based resins are produced using petroleum as the starting material. For example, low-density polyethylene is produced by addition polymerization of ethylene (ethene) obtained by refining crude oil under high-temperature and high-pressure conditions such as 300°C and 2000 atmospheres.

[0017] On the other hand, awareness of environmental issues such as the depletion of resources such as oil and global warming due to increased carbon dioxide emissions is increasing year by year. The use of ethylene resins and the like means that large amounts of carbon dioxide that was fixed in petroleum is emitted into the atmosphere from the production to disposal of petrochemical products, which means that no consideration is given to the environment.

[0018] Against this background, the development of technology to manufacture plastics from plants, which are carbon-neutral and renewable resources, has progressed, and technology has been established to produce polyethylene, the most widely used plastic, using biomass sugarcane as the starting material (Compiled by Processing Technology Research Association, Convertec 2009.9, pp. 63-67). Carbon neutral means that the amount of carbon dioxide absorbed by plants during growth is roughly equal to the amount of carbon dioxide emitted during combustion or decomposition, in other words, that they are neutral with respect to the amount of carbon circulating in the environment.

[0019] Next, the manufacturing process of the sealant film constituting the laminated film for packaging material according to this embodiment will be described. FIG. 1 is a flow chart illustrating the manufacturing process of the low-density polyethylene film derived from sugarcane, and FIG. 2 is a cross-sectional view showing a sealant film containing the low-density polyethylene resin derived from sugarcane according to this embodiment. In this embodiment, an example is shown in which sugarcane is used as the starting material for the laminated film for packaging material and the packaging bag. However, the raw material for the laminated film for packaging material and the packaging bag according to this embodiment is not limited to sugarcane, and may be any plant that is a raw material for producing low-density polyethylene resin, and may further be a renewable, biologically derived organic resource excluding fossil resources.

[0020] As shown in Figure 1, first, the sugar juice extracted from sugarcane harvested in the field is heated and concentrated, and the mixture of crystallized raw sugar and non-crystalline sugarcane molasses 1 is separated in a centrifuge. This sugarcane molasses 1, a by-product of sugar production, is used as the raw material.

[0021] Sugarcane molasses 1 is diluted with water to an appropriate concentration, fermented by yeast, and distilled to produce bioethanol 2 (step S101).

[0022] Bioethanol 2 is heated in the presence of a catalyst, and plant-derived bioethylene 3 is obtained by an intramolecular dehydration reaction (step S102).

[0023] Bioethylene 3 (monomer) is polymerized by a high pressure method to obtain a plant-derived bio-based low-density polyethylene resin 10 (step S103).

[0024] Thus, the bio-low density polyethylene resin 10 used in the sealant film constituting the laminated film for packaging material according to this embodiment is produced from ethylene derived from plants such as sugar cane as a starting material. It has been confirmed that plant-derived ethylene and polyethylene have the same quality as petroleum-derived ethylene and polyethylene. Therefore, the bio-low density polyethylene resin 10 can be produced in the same manner as low-density polyethylene resin is produced from petroleum-derived ethylene. That is, the bio-low density polyethylene resin 10 can be produced by addition polymerization of the bio-ethylene 3 under high-temperature and high-pressure conditions such as 300°C and 2000 atm.

[0025] The bio-based low-density polyethylene resin 10 has a density d of 0.910 to 0.925 g / cm, similar to petroleum-derived low-density polyethylene resins. 3 , Melt flow rate (MFR) is 0.5~ The viscosity may be in the range of 8.0 g / 10 min, and more preferably 0.7 to 5.0 g / 10 min.

[0026] The density (d, unit: g / cm 3 ) is a material with a thickness of 1 A sheet of 1 mm was used and the measurement was performed in accordance with JIS K 6760 (1981). Furthermore, the melt flow rate (MFR, unit: g / 10 min) was measured in accordance with JIS K 7210 (1995) under the conditions of a test temperature of 190°C and a test load of 21.18 N. The melt flow rate value is the amount (g) of the measurement object placed in a cylinder with a hole of 2 mm diameter at the bottom heated to 190°C and extruded in 10 minutes by applying a load of 21.18 N. The higher the degree of polymerization of the polymer, the higher the viscosity when melted, and therefore the lower the melt flow rate value tends to be.

[0027] The bio-based low-density polyethylene resin 10 having these physical properties is used to manufacture a sealant film constituting a laminate film for packaging material. At that time, petroleum-derived low-density polyethylene resin 11 is mixed as necessary. The bio-based low-density polyethylene resin 10 is mixed with the petroleum-derived low-density polyethylene resin 11 so that the content of the bio-based low-density polyethylene resin 10 is an appropriate ratio of 10 to 100 mass%.

[0028] A resin composition containing bio-based low-density polyethylene resin 10 in an appropriate ratio of 10 to 100 mol % and mixed with petroleum-derived low-density polyethylene resin 11 is formed into a film F1 containing bio-based low-density polyethylene as shown in Figure 2 (step S104).

[0029] The method for producing the sealant film constituting the laminated film for packaging material according to the present embodiment is not particularly limited, but it is preferable to use melt extrusion molding, and the inflation method, flat die method, etc. are preferably used. Furthermore, the sealant film may be processed into a multilayer structure in which a plurality of layers are superimposed, and in that case, the co-extrusion method is preferably used.

[0030] In this embodiment, the plant-derived bio-based low-density polyethylene resin 10 obtained as described above is used to manufacture a sealant film constituting a laminate film for packaging materials. This reduces the ratio of petroleum-derived resins used in the resin composition used in the laminate film for packaging materials, thereby reducing consumption of petroleum, which is a fossil resource (a depletable resource), and contributing to the prevention of global warming by reducing carbon dioxide emissions.

[0031] In this embodiment, radiocarbon dating 14 A bio-based low-density polyethylene resin 10 having a biomass ratio of 80 to 100% based on C is used.

[0032] Here, it is difficult to distinguish between plant (biomass)-derived resins and petroleum-derived resins based on physical properties such as molecular weight, mechanical properties, and thermal properties. Therefore, the biomass degree is used as a general indicator to distinguish the content ratio of plant-derived resins in a resin composition. This biomass degree is calculated by dividing the carbon content of petroleum-derived resins by the following: 14 This is because it does not contain (remain) any C (radioactive carbon-14, half-life 5730 years). 14 The biomass content is calculated by measuring the C concentration using accelerator mass spectrometry. Therefore, by measuring the biomass content of the film, it is possible to identify whether plant-derived raw materials are used and the content ratio of plant-derived resin in the resin composition.

[0033] In the first step of the biomass content measurement, the carbon dioxide generated by burning the sample to be measured and purified in a vacuum line is reduced with hydrogen using iron as a catalyst to produce graphite. This graphite is then subjected to a tandem accelerator-based 14 C-AMS (Accelerator Mass Spectrometry) dedicated equipment ( By installing it on the NEC 14 Counting C, and 13 Concentration of C ( 13 C / 12C), and 14 Concentration of C ( 14 C / 12 From these measurements, the carbon content of the sample relative to the standard modern carbon is calculated. 14 The ratio of C concentration is calculated. 14 C Measurement Standard Quantitation is performed using oxalic acid (HOx II) provided by the National Institute of Standards and Technology (NIST) as a sample.

[0034] In this embodiment, a sealant film having such a biomass degree is used. In addition, instead of being made entirely of petroleum-derived resins, in this embodiment, a petroleum-derived low-density polyethylene resin 11 is mixed (substituted) with a bio-based low-density polyethylene resin 10 that is comparable to the petroleum-derived resin in terms of physical properties, etc. This makes it possible to reduce petroleum-derived carbon dioxide emissions during the manufacture and disposal of the sealant film.

[0035] Furthermore, in this embodiment, the bio-based low-density polyethylene resin 10 contained in the resin composition has a density d of 0.910 to 0.925 g / cm 3 , Melt flow rate is 0.5~8.0 A plant-derived low-density polyethylene having a density of 10 g / 10 min is used. This allows a plant-derived sealant film with physical properties comparable to those of petroleum-derived films to be produced in the existing film manufacturing process. Therefore, the raw materials can be switched without impairing the processing suitability of the packaging material. Furthermore, the plant-derived sealant film according to this embodiment is comparable in durability to petroleum-derived films.

[0036] Further, in this embodiment, the sealant film is suitable for radiocarbon dating. 14Since the biomass degree is calculated from the measured value of C, this biomass degree can be used as an indicator to identify the origin of the raw materials of the low-density polyethylene resin that constitutes the sealant film, and it is possible to confirm the origin of the raw materials from the time of production of the film to the time of disposal.

[0037] In this embodiment, the melt flow rate (MFR) of the bio-based low-density polyethylene resin 10 constituting the sealant film is preferably 0.5 to 4.0 g / 10 min. Furthermore, in order for the sealant film to have a high biomass content and to obtain good tensile strength and seal strength as a packaging bag, the melt flow rate (MFR) of the bio-based low-density polyethylene resin 10 is more preferably 0.7 to 3.8 g / 10 min.

[0038] Next, in this embodiment, the following sealant film can be constructed using the above-mentioned bio-based low-density polyethylene resin 10 and the petroleum-derived low-density polyethylene resin 11. That is, the sealant film can be constructed as described below in (A) and (B) so that the blending amount of the bio-based low-density polyethylene resin 10 is 10 to 100 mol % and the blending amount of the petroleum-derived low-density polyethylene resin 11 is 0 to 90 mol % relative to the entire film.

[0039] First, as shown in Fig. 2 as the film F1 of (A) described above, it can have a single layer structure made of a resin composition in which bio-based low-density polyethylene resin 10 and petroleum-derived low-density polyethylene resin 11 are mixed. Here, as described above, the resin composition constituting the film F1 contains 10 to 100 mol % of the bio-based low-density polyethylene resin 10 and 0 to 90 mol % of the petroleum-derived low-density polyethylene resin 11. Therefore, when the content of the petroleum-derived low-density polyethylene resin 11 is 0 mol %, the film F1 has a single layer structure consisting of the bio-based low-density polyethylene resin 10 alone.

[0040] Fig. 3 is a cross-sectional view showing a film having a multilayer structure in which a middle layer is made of bio-based low-density polyethylene resin 10. As shown in Fig. 3 as film F2 of (B), it can also have a multilayer structure having a middle layer made of a resin composition in which bio-based low-density polyethylene resin 10 and petroleum-derived low-density polyethylene resin 11 are mixed, and outer and inner layers made of petroleum-derived low-density polyethylene resin 11. Here, similarly to film F1, The resin composition constituting the middle layer of the film F2 contains 10 to 100 mol % of bio-based low-density polyethylene resin 10 and 0 to 90 mol % of petroleum-derived low-density polyethylene resin 11. Therefore, when the content of petroleum-derived low-density polyethylene resin 11 is 0 mol %, the middle layer of the film F2 has a single layer configuration consisting of only the bio-based low-density polyethylene resin 10.

[0041] With this configuration, the ratio of petroleum-derived raw materials used in the resin composition constituting films F1 and F2 can be reduced, and petroleum-derived carbon dioxide emissions during film production and disposal can be suppressed. In addition, the use of petroleum-derived low-density polyethylene resin 11 in the inner and outer layers constituting film F2 as shown in (B) allows the film F2 to be produced, used, and processed with the same properties as existing films. The multi-layered film F2 can be produced by co-extrusion molding.

[0042] Next, in this embodiment, the above-mentioned film F1 or F2 can be used to form a laminate film for packaging material. Fig. 4 is a cross-sectional view showing a schematic example of the laminate film for packaging material.

[0043] First, the laminated film for packaging material 12 is basically constituted by laminating the above-mentioned film F1 or F2 as a sealant film 13 with a base film 14. The laminated film for packaging material 12 according to this embodiment is also suitable for radiocarbon dating. 14It is preferable that the film has a biomass degree of at least 25% calculated from the measured value of C. With this configuration, it is possible to reduce the usage ratio of the petroleum-derived low-density polyethylene resin 11 constituting each film F1 and F2 of the sealant film 13 used for heat sealing. The laminated film 12 for packaging materials according to this embodiment can conserve petroleum resources and suppress petroleum-derived carbon dioxide emissions during its production, disposal, etc.

[0044] Here, the Japan Bioplastics Association (JBPA) defines biomass plastic as "a polymeric material with a molecular weight (Mn) of 1,000 or more that contains substances derived from renewable organic resources as raw materials and is obtained by chemical or biological synthesis (excluding chemically unmodified non-thermoplastic natural organic polymeric materials)." And, by including 25.0% or more by weight of biomass-derived components in the raw material composition of biomass plastic or biomass-derived thermosetting plastic, the product can be made compliant with the "Biomass Plastic Mark."

[0045] The laminated film for packaging material 12 may have an intermediate layer 15. By changing the intermediate layer 15 in various ways, it is possible to impart various functions to the laminated film for packaging material 12, such as gas barrier properties, impact resistance, pinhole resistance, aroma retention, and chemical resistance. For example, a barrier material that suppresses the transmission of water vapor and oxygen is used for the intermediate layer 15. For example, the barrier material may be a biaxially oriented polyamide (nylon (ONy: Oriented Nylon)) film as a barrier resin, or a biaxially oriented polyethylene terephthalate (OPET: Oriented PolyEthylene Terephthalate) film as a barrier resin. ) film may be used. Furthermore, for example, a vapor deposition film in which a vapor deposition film of silica, aluminum, or the like is formed on the surface of a barrier resin may be used as the barrier material. Furthermore, for example, a metal foil of aluminum, or the like may be used as the barrier material.

[0046] The intermediate layer 15 is laminated by being bonded to the sealant film 13 by an adhesive layer 16 and to the base film 14 by an adhesive layer 17. The materials of the adhesive layer 16 and the adhesive layer 17 are appropriately selected depending on the type of base material and the bonding method. Examples of the lamination (bonding) method include a dry lamination method and a melt extrusion lamination method.

[0047] The adhesive layer 16, which is the lamination adhesive layer in the dry lamination method, and the adhesive layer 17 are made of a material such as a polyester adhesive or a polyether adhesive. Preferably, a two-liquid curing urethane adhesive is used. On the other hand, materials for the adhesive layer 16 and adhesive layer 17, which become the melt-extruded resin layer in the melt-extrusion lamination method, include polyethylene and polypropylene, and it is preferable to use low-density polyethylene from the viewpoint of substrate adhesion depending on the type of substrate. Furthermore, a dry lamination method and a melt-extrusion lamination method may be used in combination. Surface modification treatments such as corona discharge treatment, ozone treatment, and plasma treatment may be performed on the surfaces before each layer is bonded as necessary to improve adhesion, and an anchor coating agent may be applied.

[0048] A printed layer 18 may be formed on any of the layers constituting the laminated film for packaging material 12. The printing of characters, figures, symbols, patterns, etc. is not particularly limited as long as it is in a position that is visible from the outside of the packaging container, and may be surface printing. In the layer structure illustrated in FIG. 4, the printed layer 18 is formed on the inside of the base film 14. A white underlayer may be provided on the printed layer 18. The printed layer 18 is formed by printing using gravure printing ink or the like by a printing method such as gravure printing, letterpress printing, screen printing, transfer printing, flexography printing, etc.

[0049] The packaging laminate film 12 may further have an outer layer (not shown) laminated on the base film 14 .

[0050] Examples of the base film 14 that can be used include various resin films and sheets such as polyethylene resins, polypropylene resins, cyclic polyolefin resins, polystyrene resins, acrylonitrile-styrene copolymers (AS resins), acrylonitrile-butadiene-styrene copolymers (ABS resins), polyvinyl chloride resins, fluorine resins, poly(meth)acrylic resins, polycarbonate resins, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, polyamide resins such as various nylons, polyimide resins, polyamideimide resins, polyarylphthalate resins, silicone resins, polysulfone resins, polyphenylene sulfide resins, polyethersulfone resins, polyurethane resins, acetal resins, and cellulose resins.

[0051] It is preferable to use a biaxially oriented polypropylene film (OPP: Oriented Polypolypropylene) or a biaxially oriented polyethylene terephthalate (OPET) for the base film 14. The biaxially oriented polypropylene film is excellent in moisture resistance, water resistance, chemical resistance, etc., and is highly versatile and inexpensive. The biaxially oriented polyethylene terephthalate has low moisture absorption and excellent aroma retention in addition to scratch resistance, heat resistance, water resistance, etc. The packaging laminate film 12 using these base films 14 has tensile strength, seal strength, and stiffness suitable for a packaging bag, for example a soft packaging bag, and shows excellent processability.

[0052] Furthermore, in this embodiment, the raw material of the biaxially oriented polyethylene terephthalate used for the base film 14 may be derived from plants.

[0053] Next, a manufacturing process of the plant-derived base film 14 constituting the packaging laminate film 12 according to this embodiment will be described. FIG. 5 is a flow chart illustrating an example of a manufacturing process of a plant-derived polyethylene terephthalate film. In this example, sugar cane is used as a starting material for the plant-derived polyethylene terephthalate film, i.e., the bio-PET film F3 (see FIG. 1). However, the raw material for the bio-PET film F3 according to this embodiment is not limited to sugar cane, and may be any plant that is a raw material for producing polyethylene terephthalate resin, and may further be a renewable, biologically derived organic resource excluding fossil resources.

[0054] First, by going through steps S101 and S102 in FIG. Bioethylene 3 is obtained.

[0055] Bioethylene oxide 4 (1,2-epoxyethane) is obtained by oxidizing bioethylene 3 (step S201). Bioethylene oxide 4 is obtained, for example, by pressurizing and heating bioethylene 3 to 1 to 3 MPa and 200 to 300°C in the presence of a silver catalyst and catalytically oxidizing it with molecular oxygen or a molecular oxygen-containing gas. Bioethylene oxide 4 may also be produced by reacting bioethylene 3 with hydrogen peroxide or a peracid.

[0056] Bioethylene oxide 4 is hydrolyzed under an acid catalyst to obtain plant-derived bioethylene glycol (MEG: Mono Ethylene Glycol) (ethane-1,2-diol) 5 (step S202). The biomass content of this bioMEG 5 can be set to 100%.

[0057] Meanwhile, paraxylene 6, a secondary product of petroleum, is oxidized and refined to a high purity to obtain purified terephthalic acid (PTA) 7 (step S203).

[0058] Bio-PET resin 19 containing plant-derived raw materials is obtained by condensation polymerization of bio-MEG5 and purified terephthalic acid (PTA) 7 (step S204). Note that the bio-PET resin 19 has a biomass content of 30% since 30% of the raw materials are bio-MEG5 and 70% are purified terephthalic acid (PTA) 7.

[0059] The bio-PET resin 19 is formed into a film to form a bio-PET film F3 (step S205). The bio-PET film F3 thus obtained is used as the base film 14 constituting the laminate film for packaging material 12 as required. In this way, the present embodiment further reduces the ratio of petroleum-derived resin to the resin composition used in the laminate film for packaging material 12, thereby further reducing consumption of petroleum, which is a fossil resource (a depletable resource), and contributing to the prevention of global warming by reducing carbon dioxide emissions. More specifically, the bio-PET film F3 can reduce CO2 by about 10% over its entire life cycle from raw material procurement to disposal compared to petroleum-derived PET film.

[0060] In addition, the bio-PET film F3 has 2 carbon atoms derived from bio-MEG5 and 8 carbon atoms derived from purified terephthalic acid (PTA)7, so the biomass ratio is 20%. On the other hand, the molecular weight of the PET structural unit is 192, and the molecular weight derived from ethylene glycol is 60. Therefore, the biomass ratio by weight method is 60 / 192=31.25%.

[0061] 6 is a cross-sectional view showing a schematic example of a packaging bag produced by heat sealing a packaging laminate film 12. The packaging laminate film 12 is produced by heat sealing (thermocompression bonding) its peripheral edge. The packaging laminate film 12 shown here is an example consisting of two layers, a sealant film 13 and a base film 14. Here, the adhesive layer is omitted from the illustration.

[0062] One laminate film 12 for packaging material is folded or two laminate films 12 for packaging material are overlapped so that the surfaces of the sealant films 13, which are the inner layers of the laminate film 12 for packaging material, face each other, and the outer peripheral edges are heat-sealed. As a heat-sealing method, bar sealing, rotary roll sealing, belt sealing, impulse sealing, high frequency sealing, ultrasonic sealing, etc. can be used. Fig. 6 shows an example in which two laminate films 12A and 12B for packaging material are overlapped.

[0063] Heating and pressure are applied from the sides of the base films 14A and 14B, which are the outer layers of the two laminate films for packaging material 12A and 12B, using a heating roller or the like (not shown). The heat melts the sealant films 13A and 13B, and the pressure brings the sealant films 13A and 13B into close contact with each other. As a result, a seal portion 21 is formed at the outer peripheral ends of the two laminate films for packaging material 12A and 12B.

[0064] Such a sealed portion 21 is formed on three sides of, for example, two rectangular laminated films for packaging material 12A and 12B, and the remaining side is used as a filling port for the contents. Then, a sealed portion 21 is further formed on the side after the contents are filled from the filling port, thereby forming a completed packaging bag (four-side sealed bag 20).

[0065] 7 is a perspective view showing a four-side sealed bag 20 as an example of a packaging bag formed using the packaging laminate film 12 according to this embodiment. In this manner, a flexible packaging bag in which frozen foods such as fried rice are filled and packaged can be formed using the flexible packaging material consisting of the sealant film 13 according to this embodiment and the base film 14.

[0066] By adopting such a configuration, the ratio of petroleum-derived raw materials used in the laminated film 12 for packaging material constituting the packaging bag can be reduced, and petroleum resources can be saved and petroleum-derived carbon dioxide emissions can be suppressed during the manufacture and disposal of the packaging bag. In particular, since soft packaging bags tend to be disposable, the laminated film 12 for packaging material according to this embodiment, which reduces the amount of petroleum resources used and suppresses petroleum-derived carbon dioxide emissions, can provide an effect of providing an environmentally friendly packaging bag. Furthermore, as described above, the processing suitability and physical properties of the laminated film 12 for packaging material according to this embodiment are comparable to those of petroleum-derived materials. Therefore, according to the configuration according to this embodiment, a packaging bag can be provided that contains the bio-low-density polyethylene resin 10 that conserves petroleum resources and reduces the environmental load, and has processing suitability and physical properties, especially durability, that are comparable to those of petroleum-based resins.

[0067] The end of the packaging bag may be provided with a cut line for opening using a laser or the like. Furthermore, the packaging bag according to this embodiment may be optionally equipped with a one-piece or two-piece type spout, a fastener for resealing, etc. Naturally, the bio-based low-density polyethylene resin 10 or the bio-based PET resin 19 may be used as the material for these.

[0068] In addition to the four-sided sealed bag 20 illustrated in FIG. 7, various types of packaging bags according to this embodiment can be manufactured by heat sealing in a heat sealing form such as a side seal type, a two-sided seal type, a three-sided seal type, an envelope seal type, a grooving seal type (pillow seal type), a pleated seal type, a flat bottom seal type, a square bottom seal type, and others. Furthermore, in this embodiment, by using the above-mentioned laminated film for packaging material 12, it is possible to manufacture self-supporting packaging bags (standing pouches), containers including tube containers, liquid paper containers, container lids, container labels, and the like. Furthermore, the contents of the packaging bag according to this embodiment are not limited to the exemplified foods and beverages, but can also contain cosmetics, medicines, miscellaneous goods, and the like, which further reduces the ratio of petroleum-derived materials used and greatly suppresses petroleum-derived carbon dioxide emissions.

[0069] In this embodiment, it is preferable that the biomass degree of the entire packaging material is 25% or more. Therefore, when the base film 14 is made of a bio-PET film F3 having a biomass degree of 20%, the sealant film 13 may contain, for example, about 35% of the bio-low density polyethylene resin 10. On the other hand, when the base film 14 has a biomass degree of 0%, the sealant film 13 may contain, for example, about 35% of the bio-low density polyethylene resin 10. The proportion of 0 is increased to, for example, 70%. In this manner, in this embodiment, the biomass degree of the entire packaging material is set to at least 25% or more.

[0070] The present invention can further have the following aspects as a means for solving the above problems. The present invention relates to a laminated film for packaging material, which is obtained by laminating a base film and a sealant film made of a resin composition containing a plant-derived low-density polyethylene resin obtained by polymerizing plant-derived ethylene by a high-pressure method, and the laminated film for packaging material is a film that can be used for radiocarbon dating. 14 The biomass ratio calculated from the measured value of C is at least 25%. Furthermore, the plant-derived low-density polyethylene resin is characterized by having a biomass ratio of 10 to 100%. Furthermore, the base film is characterized in that it is a film made of a resin composition containing a plant-derived polyethylene terephthalate resin obtained by condensation polymerization of plant-derived ethylene glycol and petroleum-derived terephthalic acid. Furthermore, the sealant film is characterized in that it is composed of either (A) or (B) below using the resin composition containing 10 to 100 mol % of the plant-derived low-density polyethylene resin and 0 to 90 mol % of the petroleum-derived low-density polyethylene resin. (A) A single-layer structure obtained by mixing the resin composition and the petroleum-derived low-density polyethylene resin (B) A multi-layer structure in which a middle layer is a layer made of a mixture of the resin composition and the petroleum-derived low-density polyethylene resin, and an outer layer and an inner layer are made of the petroleum-derived low-density polyethylene resin. The present invention is further characterized in that an intermediate layer is provided between the sealant film and the base film. Furthermore, the packaging bag of the present invention is characterized in that it is made using the above-mentioned laminated film for packaging materials. EXAMPLES

[0071] The present disclosure will be described in more detail and specifically below with reference to examples. However, the present disclosure is not limited to the following examples.

[0072] [Example 1] (1) Resin composition Low-density polyethylene (Japan Polyethylene Corporation LC525: density d = 0.923 g / cm 3 50.0 parts by weight of ethylenediaminetetraacetate (melt flow rate (MFR) = 3.5 g / 10 min) Omas low-density polyethylene (SEB853 manufactured by Braskem Corporation: density d = 0.923 g / cm 3 50.0 parts by weight of a polymer having a melt flow rate (MFR) of 2.7 g / 10 min. The mixture was kneaded to prepare a resin composition.

[0073] (2) Film Next, the resin composition prepared in (1) was used to produce a monolayer film having a thickness of 30 μm according to this example using a single-layer top-blown air-cooled inflation co-extrusion film-forming machine. That is, the monolayer film according to Example 1 is a film F1 containing bio-based low-density polyethylene as shown in Figure 2. One surface of the produced monolayer film was subjected to a corona discharge surface treatment (hereinafter referred to as corona treatment).

[0074] (3) Laminated materials One side of a 15 μm thick biaxially oriented nylon 6 film is corona-treated, and the desired print pattern is formed on the corona-treated surface by gravure printing using a normal gravure ink composition. After that, a two-component curing polyurethane laminating adhesive is applied to the entire surface including the print pattern. The coating agent was applied to a thickness of 4.0 g / m2 using the gravure roll coating method. 2 (Dry state) The laminate was coated with a coating to form an adhesive layer for lamination, and then the corona-treated surface of the monolayer film produced in (2) was placed against the adhesive layer for lamination, and then the two were dry-laminated to produce a laminate.

[0075] (4)Flexible packaging products Next, two sheets of the laminate produced in (3) were prepared and overlapped with the film sides of (2) facing each other, and then the edges around the periphery were heat-sealed on three sides to form a sealed portion 21 and produce a three-sided sealed flexible packaging bag having an opening at the top. Snack food was filled and packaged in the three-sided sealed flexible packaging bag through the opening, and then the edges of the opening were heat-sealed to form a sealed portion 21, producing a flexible packaging product.

[0076] [Example 2] (1) Resin composition Low-density polyethylene (Japan Polyethylene Corporation LC522: density d = 0.923 g / cm 330.0 parts by weight of ethylenediaminetetraacetate (melt flow rate (MFR) = 4.0 g / 10 min) Omas low-density polyethylene (SPB681 manufactured by Braskem Corporation: density d = 0.922 g / cm 3 , melt flow rate (MFR) = 3.8 g / 10 min) 70.0 parts by weight The mixture was kneaded to prepare a resin composition.

[0077] (2) Film Next, the resin composition prepared in (1) was used to produce a monolayer film having a thickness of 50 μm according to this example using a single-layer top-blown air-cooled inflation co-extrusion film-forming machine. That is, the monolayer film according to Example 2 is a film F1 containing bio-based low-density polyethylene as shown in Figure 2. One surface of the produced monolayer film was subjected to a corona treatment.

[0078] (3) Laminated materials One side of a biaxially oriented PET film with a thickness of 12 μm was subjected to a corona treatment, and a desired print pattern was formed on the corona-treated surface by a gravure printing method using a normal gravure ink composition. After that, a two-component curing polyurethane laminating adhesive was applied to the entire surface including the print pattern to a thickness of 4.0 g / m using a gravure roll coating method. 2 (Dry state) The laminate was then laminated with the corona-treated surface of the monolayer film produced in (2) facing the adhesive layer, and then the two were dry-laminated to produce a laminate.

[0079] (4)Flexible packaging products Next, two sheets of the laminate produced in (3) were prepared and overlapped with the film sides of (2) facing each other, and then the edges around the periphery were heat-sealed on three sides to form a sealed portion 21 and produce a three-sided sealed flexible packaging bag having an opening at the top. Snack food was filled and packaged in the three-sided sealed flexible packaging bag through the opening, and then the edges of the opening were heat-sealed to form a sealed portion 21, producing a flexible packaging product.

[0080] [Example 3] (1) Resin composition First, the following resin compositions (a), (b), and (c) were prepared. (A) Resin composition constituting the first layer Low-density polyethylene (Japan Polyethylene Corporation LC522: density d = 0.923 g / cm 3 , melt flow rate (MFR) = 4.0 g / 10 min) 100.0 parts by weight, A resin composition was prepared by thoroughly kneading 0.5 part by weight of synthetic silica and 0.05 part by weight of erucic acid amide. (b) Resin composition constituting the second layer Biomass low-density polyethylene (SPB681 manufactured by Braskem Corporation: density d = 0.922 g / cm 3 , melt flow rate (MFR) = 3.8 g / 10 min) 100.0 parts by weight was prepared. (C) Resin composition constituting the third layer Low-density polyethylene (Japan Polyethylene Corporation LC522: density d = 0.923 g / cm 3 , melt flow rate (MFR) = 4.0 g / 10 min) 100.0 parts by weight, A resin composition was prepared by thoroughly kneading 0.5 part by weight of synthetic silica and 0.05 part by weight of erucic acid amide.

[0081] (2) Film Next, the resin compositions prepared in (1) were used, and these were co-extruded using a three-kind, three-layer, top-blown, air-cooled inflation co-extrusion film-forming machine to produce a layer of resin composition (A) at 10 μm, a layer of resin composition (B) at 30 μm, and a layer of resin composition (C) at 10 μm, respectively, to produce a multilayer laminate film according to this embodiment, which is a co-extruded inflation film with a total thickness of 50 μm for the three layers. That is, the multilayer laminate film according to Example 3 is a film F2 having a multilayer structure in which the middle layer is a bio-low density polyethylene resin 10 as shown in FIG. 3. The surface of the first layer (A) of the produced multilayer laminate film was subjected to a corona treatment.

[0082] (3) Laminated materials One side of a biaxially oriented PET film with a thickness of 12 μm was subjected to a corona treatment, and a desired print pattern was formed on the corona-treated surface by a gravure printing method using a normal gravure ink composition. After that, a two-component curing polyurethane laminating adhesive was applied to the entire surface including the print pattern to a thickness of 4.0 g / m using a gravure roll coating method. 2 (Dry state) The laminate was then laminated with the corona-treated surface of the layer made of the resin composition of the first layer (a) of the multilayer laminate resin film produced in (2) facing the surface of the adhesive layer for lamination, and then the two were laminated by dry lamination to produce a laminate.

[0083] (4)Flexible packaging products Next, two sheets of the laminated material produced in (3) were prepared and overlapped with the faces of the third layers (c) facing each other, and then the edges around the periphery were heat-sealed on three sides to form a sealed portion 21 and produce a three-sided sealed flexible packaging bag having an opening at the top. Snack food was filled and packaged in the three-sided sealed flexible packaging bag through the opening, and then the edges of the opening were heat-sealed to form a sealed portion 21, producing a flexible packaging product.

[0084] [Example 4] (1) Resin composition Low-density polyethylene (Japan Polyethylene Corporation LC520: density d = 0.923 g / cm 3 30.0 parts by weight of ethylenediaminetetraacetate (melt flow rate (MFR) = 3.6 g / 10 min) Omas low-density polyethylene (SEB853 manufactured by Braskem Corporation: density d = 0.923 g / cm 3 , melt flow rate (MFR) = 2.7 g / 10 min) 70.0 parts by weight The mixture was kneaded to prepare a resin composition.

[0085] (2) Film Next, the resin composition prepared in (1) was used to produce a monolayer film having a thickness of 50 μm according to this example using a single-layer top-blown air-cooled inflation co-extrusion film-forming machine. That is, the monolayer film according to Example 4 is a film F1 containing bio-based low-density polyethylene as shown in Figure 2. One surface of the produced monolayer film was subjected to a corona treatment.

[0086] (3) Laminated materials One side of a 12 μm-thick biaxially oriented PET film was corona-treated, and a two-component curing polyurethane laminating adhesive was applied to the corona-treated surface at a thickness of 3.0 g / m. 2 (dry form Then, a 12 μm-thick biaxially oriented PET film that had been corona-treated on both sides was laminated on the adhesive layer, and a two-component curing polyurethane-based laminating adhesive was applied to a thickness of 3.0 g / m2 on the laminated biaxially oriented PET film that had been corona-treated on both sides in the same manner as above. 2 Apply so that the surface becomes dry. An adhesive layer was formed to obtain a base film 14. The adhesive layer surface of the base film 14 and the corona-treated surface of the single layer film produced in (2) were placed opposite each other to obtain a multilayer laminate film with the base film 14 of this example laminated thereon.

[0087] (4)Flexible packaging products Next, two sheets of the laminate produced in (3) were prepared and overlapped with the film sides of (2) facing each other, and then the edges around the periphery were heat-sealed on three sides to form a sealed portion 21 and produce a three-sided sealed flexible packaging bag having an opening at the top. Snack food was filled and packaged in the three-sided sealed flexible packaging bag through the opening, and then the edges of the opening were heat-sealed to form a sealed portion 21, producing a flexible packaging product.

[0088] [Example 5] (1) Resin composition First, the following resin compositions (a), (b), and (c) were prepared. (A) Resin composition constituting the first layer Low-density polyethylene (Japan Polyethylene Corporation LC522: density d = 0.923 g / cm 3 , melt flow rate (MFR) = 4.0 g / 10 min) 100.0 parts by weight, A resin composition was prepared by thoroughly kneading 0.5 part by weight of synthetic silica and 0.05 part by weight of erucic acid amide. (b) Resin composition constituting the second layer Biomass low-density polyethylene (SPB681 manufactured by Braskem Corporation: density d = 0.922 g / cm 3 , melt flow rate (MFR) = 3.8 g / 10 min) 100.0 parts by weight was prepared. (C) Resin composition constituting the third layer Low-density polyethylene (Japan Polyethylene Corporation LC522: density d = 0.923 g / cm 3 , melt flow rate (MFR) = 4.0 g / 10 min) 100.0 parts by weight, A resin composition was prepared by thoroughly kneading 0.5 part by weight of synthetic silica and 0.05 part by weight of erucic acid amide.

[0089] (2) Film Next, the resin compositions prepared in (1) were used, and these were co-extruded using a three-kind, three-layer, top-blown, air-cooled inflation co-extrusion film-forming machine to produce a layer of resin composition (A) at 10 μm, a layer of resin composition (B) at 30 μm, and a layer of resin composition (C) at 10 μm, respectively, to produce a multilayer laminate film according to this embodiment, which is a co-extruded inflation film with a total thickness of 50 μm for the three layers. That is, the multilayer laminate film according to Example 5 is a film F2 having a multilayer structure in which the middle layer is a bio-low density polyethylene resin 10 as shown in FIG. 3. The surface of the first layer (A) of the produced multilayer laminate film was subjected to a corona treatment.

[0090] (3) Laminated materials One side of a 12 μm-thick biaxially oriented PET film was corona-treated, and a two-component curing polyurethane laminating adhesive was applied to the corona-treated surface at a thickness of 3.0 g / m.2 (dry form Then, a 15 μm-thick biaxially oriented nylon 6 film that had been corona-treated on both sides was laminated on the adhesive layer, and a 3.0 g / m-thick two-component curing polyurethane laminating adhesive was applied to the surface of the biaxially oriented nylon 6 film that had been corona-treated on both sides in the same manner as above. 2 (Dry state) The adhesive layer was formed to obtain a base film 14. The adhesive layer surface of the base film 14 and the corona-treated surface of the coextruded multilayer laminate film (2) were placed opposite each other to obtain a multilayer laminate film laminated with the base film 14 of this example.

[0091] (4)Flexible packaging products Next, two sheets of the laminated material produced in (3) were prepared and overlapped with the faces of the third layers (c) facing each other, and then the edges around the periphery were heat-sealed on three sides to form a sealed portion 21 and produce a three-side sealed flexible packaging bag having an opening at the top. The three-side sealed flexible packaging bag was filled and packaged with quick-frozen fried rice through the opening, and then the edges of the opening were heat-sealed to form a sealed portion 21, producing a flexible packaging product.

[0092] [Example 6] (1) Resin composition Low-density polyethylene (Japan Polyethylene Corporation LC525: density d = 0.923 g / cm 3 20.0 parts by weight of ethylenediaminetetraacetate (melt flow rate (MFR) = 3.5 g / 10 min) Omas low-density polyethylene (SEB853 manufactured by Braskem Corporation: density d = 0.923 g / cm 3 80.0 parts by weight of a polymer having a melt flow rate (MFR) of 2.7 g / 10 min. The mixture was kneaded to prepare a resin composition.

[0093] (2) Film Next, using each of the resin compositions prepared in (1), a monolayer film having a thickness of 30 μm according to this example was produced using a single-layer top-blown air-cooled inflation co-extrusion film-forming machine. That is, the monolayer film according to Example 6 is a film F1 containing bio-based low-density polyethylene as shown in Figure 2. One surface of the produced monolayer film was subjected to a corona treatment.

[0094] (3) Laminated materials One side of a 12 μm-thick biaxially oriented biomass PET film (Bio-PET Film F3) was corona-treated, and a desired print pattern was formed on the corona-treated surface by gravure printing using a normal gravure ink composition. After that, a two-component curing polyurethane laminating adhesive was applied to the entire surface including the print pattern to a thickness of 4.0 g / m using the gravure roll coating method. 2 (dry state) to form an adhesive layer for lamination, and then Next, the corona-treated surface of the monolayer film produced in (2) was placed against the surface of the laminating adhesive layer, and then the two were dry-laminated to produce a laminate.

[0095] (4)Flexible packaging products Next, two sheets of the laminate produced in (3) were prepared and overlapped with the film sides of (2) facing each other, and then the edges around the periphery were heat-sealed on three sides to form a sealed portion 21 and produce a three-side sealed flexible packaging bag having an opening at the top. The three-side sealed flexible packaging bag was filled and packaged with quick-frozen fried rice through the opening, and then the edges of the opening were heat-sealed to form a sealed portion 21, producing a flexible packaging product.

[0096] As described above in detail, the films F1 and F2 made of the low-density polyethylene resin of the present disclosure are made of a resin composition containing the bio-based low-density polyethylene resin 10 obtained by a high-pressure polymerization method. The laminated film 12 is laminated with the base film 14 to form a packaging material laminate film 12, and the packaging bag is made of this laminated film 12. [Industrial Applicability]

[0097] The present disclosure can be applied to any product using a polyethylene-based resin, such as a film made of a polyethylene-based resin, and a packaging bag or container made of this film. [Explanation of symbols]

[0098] 10. Bio-based low density polyethylene resin 11 Petroleum-derived low-density polyethylene resin 12 Laminated film for packaging materials 13 Sealant film 14 Base film 19 Bio-PET resin 20 Four-sided sealed bag (packaging bag) F1, F2 film (sealant film) F3 Bio PET film

Claims

1. A laminated film for packaging material, comprising: A sealant film made of a resin composition containing a plant-derived low-density polyethylene resin obtained by polymerizing plant-derived ethylene by a high-pressure method; An intermediate layer for imparting gas barrier properties; A substrate film having a printed pattern, the base film is a polypropylene-based resin or a polyester-based resin, the base film having the printed pattern, the intermediate layer for imparting gas barrier properties, and the sealant film are laminated via a laminating adhesive; The laminated film for packaging is radiocarbon dated. 14 C has a biomass degree of at least 25% calculated from the measured value, The plant-derived low-density polyethylene resin has a biomass content of 10 to 100%, The sealant film does not contain 0.2% by mass or more of silica, 5.0% by mass or more of titanium oxide, an ionomer, or an ethylene-methacrylic acid copolymer; The sealant film is a laminated film for packaging materials, characterized in that the constituent resin of the sealant film is a resin composition consisting of 10 to 100% by weight of the plant-derived low-density polyethylene resin and 0 to 90% by weight of a petroleum-derived low-density polyethylene resin, and is composed of either (A) or (B) below. (A) A single layer structure made of the resin composition (B) A multi-layer structure in which the middle layer is made of the resin composition, and the outer and inner layers are made of the petroleum-derived low-density polyethylene resin.

2. The laminate film for packaging materials according to claim 1, characterized in that the base film is a film made of a resin composition containing a plant-derived polyethylene terephthalate resin obtained by condensation polymerization of plant-derived ethylene glycol and petroleum-derived terephthalic acid.

3. A packaging bag comprising the laminated film for packaging materials according to claim 1 or 2.

Images